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• The hygroscopic property of paper fiber is used to prepare a bifunctional catalyst. • The impregnation time for preparing the hollow microtubular Ni-MgO-CaO is 1 min. • 94.1 % of hydrogen is stably produced on 5Ni-10MgO-CaO from biogas for 50 cycles. • Only 37.1 % loss of the sorption-enhanced effect is shown during the entire cycle. Sorption-enhanced steam reforming (SESR) process is a promising technology aiming at the production of high purity hydrogen with CO 2 capture. The key to the success of this process is the availability of high-performance bifunctional catalysts. Herein, we develop a hollow microtubular Ni-MgO-CaO bifunctional catalyst with paper fiber as template. Due to the strong hygroscopic properties of paper fibers, it provides a method for the rapid synthesis of catalysts with design components by adsorbing solution. The characterizations indicate that the impregnation time (1 min vs 24 h) has no effect on the structural properties of Ni-MgO-CaO bifunctional catalysts. MgO as an inert spacer can weaken the sintering of CaO to ensure a stable CO 2 uptake. Moreover, the agglomeration of Ni particles is inhibited by the MgO coating on their surface. 5Ni-10MgO-CaO as the best performing catalyst displays high stability for the SESR of biogas (SESRB) reaction, during which 94.1 % purity of hydrogen with a 95.2 % conversion of CH 4 is stably produced and only 37.1 % decrease of sorption-enhanced effect is observed in 50 SESRB-calcination cycles. [ABSTRACT FROM AUTHOR]

A scalable papermaking process was employed herein to manufacture cellulosic papers from native and phosphorylated cellulose microfibers (referred to as CMF and PCMF, respectively) impregnated with polyethyleneimine (PEI) for Direct Air Capture (DAC) applications. These papers were analyzed in terms of their physico-chemical properties using several techniques. The impact of PEI content on desorbing the co-adsorbed H 2 O and CO 2 from the air, as well as on the anisotropic microporous network, was explicitly analyzed. The results indicated that phosphorylation promotes the uptake of both CO 2 and H 2 O in the corresponding neat and PEI-loaded papers, reaching a superior CO 2 adsorption capacity of ∼0.7–0.9 mmol.g−1 for PCMF papers versus 0.07–0.3 mmol.g−1 for CMF papers. Furthermore, the CMF and PCMF papers exhibited H 2 O adsorption capacities in the range of 1.5–1.8 mmol.g−1 and 2.2–3.8 mmol.g−1, respectively. This work further highlights the combined role of phosphorylation and favorable PEI impregnation in tuning the cellulose CO 2 adsorption properties under humid conditions, facilitating the rapid release of the adsorbed CO 2 under mid conditions. [Display omitted] • Manufacturing of scalable solid cellulosic papers with amine functionalities and enhanced carbon capture. • Microstructural and chemical characterization of amine functionalized paper with various amine ratios. • Valorization of Alfa biomass in Carbon capture applications. • The combined role of phosphorylation and PEI impregnation in tuning the H 2 O and CO 2 co-adsorption properties. [ABSTRACT FROM AUTHOR]

Hydrogen Economy and Cyclic Economy are advocated, together with the use of perennial (solar, wind, hydro, geo-power, SWHG) and renewable (biomass) energy sources, for defossilizing anthropic activities and mitigating climate change. Each option has intrinsic limits that prevent a stand-alone success in reaching the target. Humans have recycled goods (metals, water, paper, and now plastics) to a different extent since very long time. Recycling carbon (which is already performed at the industrial level in the form of CO 2 utilization and with recycling paper and plastics) is a key point for the future. The conversion of CO 2 into chemicals and materials is carried out since the late 1800s (Solvay process) and is today performed at scale of 230 Mt/y. It is time to implement on a scale of several Gt/y the conversion of CO 2 into energy products, possibly mimicking Nature which does not use hydrogen. In the short term, a few conditions must be met to make operative on a large scale the production of fuels from recycled-C, namely the availability of low-cost: i. abundant, pure concentrated streams of CO 2 , ii. non-fossil primary energy sources, and iii. non-fossil-hydrogen. The large-scale production of hydrogen by Methane Steam Reforming with CO 2 capture (Blue-H 2) seems to be a realistic and sustainable solution. Green-H 2 could in principle be produced on a large scale through the electrolysis of water powered by perennial primary sources, but hurdles such as the availability of materials for the construction of long-living, robust electrochemical cells (membranes, electrodes) must be abated for a substantial scale-up with respect to existing capacity. The actual political situation makes difficult to rely on external supplies. Supposed that cheap hydrogen will be available, its direct use in energy production can be confronted with the indirect use that implies the hydrogenation of CO 2 into fuels (E-fuels), an almost ready technology. The two strategies have both pros and cons and can be integrated. E-Fuels can also represent an option for storing the energy of intermittent sources. In the medium-long term, the direct co-processing of CO 2 and water via co-electrolysis may avoid the production/transport/ use of hydrogen. In the long term, coprocessing of CO 2 and H 2 O to fuels via photochemical or photoelectrochemical processes can become a strategic technology. • Hydrogen Economy and Cyclic Economy are discussed as an option for defossilizing anthropic activities and mitigating climate change. • In the short term, a few conditions must be met to make operative on a large scale the production of fuels from recycled-C. • In the medium-long term, the direct co-processing of CO 2 and water via co-electrolysis may avoid the production/transport/ use of hydrogen. • In the long term, coprocessing of CO 2 and H 2 O to fuels via photochemical or photoelectrochemical processes can become a strategic technology. [ABSTRACT FROM AUTHOR]

Blue hydrogen (H 2) serves as a pivotal initial step towards emissions reduction and a seamless transition to green hydrogen by providing a cleaner alternative to grey hydrogen. Blue H 2 can be obtained through diverse pathways (i.e. , distinct processes and stages) within the hydrogen supply network (HSN), resulting in varying greenhouse gas emission levels. This paper uses the Life Cycle Assessment methodology to compare 18 different blue HSN pathways. Blue hydrogen is produced from three different processes (i.e. , Steam Methane Reforming (SMR), Partial Oxidation of Methane (POM), and Auto-Thermal Reforming (ATR)) that are coupled with carbon capture unit (CCU). Moreover, it can be conditioned to different states or carriers (i.e. , liquefied H 2 , compressed H 2 , ammonia, and methanol), stored using various methods, transported by different means according to its state, and reconditioned to its original state at end-users. The LCA results indicate that the NH 3 pathway has the least environmental impact measuring just 2.12 kgCO 2equ / kgH 2 compared to the other 18 blue HSN pathways. This pathway involves producing hydrogen from ATR process coupled with CCS, and eventually delivering as ammonia to consumers. Additionally, the blue H 2 results of this paper are compared to the green H 2 results discussed in the previous paper. The comparison highlights that integrating renewable energy in the form concentrated photovoltaic collectors produces the lowest emissions compared to all pathways. It reduces the emissions from 45.3% to 67% depending on the pathways, compared to the ATR process coupled with CCU. • SMR, POM, or ATR with carbon capture for blue hydrogen production. • This LCA study compares 18 blue HSN pathways for their environmental performance. • Different pathways within the HSN lead to various levels of GHG emissions. • NH 3 path emits the least emissions (2.12 kgCO 2equ /kgH 2) among blue H 2 paths. • CH 2 path emits the least emissions (0.080 kgCO 2equ /kWh) among all paths. [ABSTRACT FROM AUTHOR]

This paper explores green hydrogen-based carbon dioxide (CO 2) hydrogenation for the production of oxygenates, presenting it as a pivotal strategy for mitigating carbon emissions and advancing sustainable energy solutions. The conversion of CO 2 into oxygenates through hydrogenation emerges as a promising avenue, particularly in the context of transportation applications where the storage of hydrogen poses challenges. The substitution of fossil diesel and gasoline fuels with green hydrogen-derived dimethyl ether, or methanol/ethanol, is advantageous from a life cycle analysis (LCA) CO 2 emission perspective even without the capture of the CO 2. However, the greatest sustainability appeal is contingent on the crucial aspect of capturing CO 2 when utilizing these fuels, which is an aspect currently absent in the literature. This narrative review comprehensively explores catalytic processes, mechanisms, sustainability perspectives, and the current state of research in this evolving area. It encompasses both the production of oxygenates through CO 2 hydrogenation and the subsequent utilization of these oxygenates in fuel cells or combustion systems, emphasizing the integration of CO 2 capture technologies. The paper contributes to the discourse surrounding the environmental and technological dimensions of energy storage ecosystems, providing a holistic view of their potential to foster sustainable energy solutions. [ABSTRACT FROM AUTHOR]

South Africa is an energy-intensive developing country in Africa and ranked as the 1st and 14th emitter of greenhouse gas (GHG) in Africa and the world, respectively. The abundance and availability of coal in South Africa make it the mainstay primary source of energy contributing 56% of national total GHG emissions. This paper focused on the duo of energy generation and emission associated with coal processing and utilization in South Africa, and the urgent need to advance coal processing technologies marked by high carbon footprints in consonance with the sustainable development goals. Different gasification techniques and their performances have been compiled and discussed. The economic, environmental impact, energetic, and exergetic characteristics of existing hydrogen production technologies for renewable and non-renewable energy sources have been examined along with hydrogen production from plasma gasification of coal. Hydrogen production via coal or coal/biomass plasma gasification technology (nuclear-, wind-, PV solar-, and concentrated solar power-driven) in addition to carbon capture technology for transforming the captured CO 2 into value-added products appears to be the most viable option to considerably reduce emissions and meet the energy demand of South Africa. This proposed technology can be pivotal to achieving a low-carbon economy (medium-term) and transition to hydrogen economy (long-term) as championed by the global sustainable development agenda. Conclusively, hydrogen (stored in different forms e.g., liquid hydrogen, ammonia, and organic hydride) seems to find more applications (in the space industry, transport, energy storage, defense industry, etc.) than coal owing to its immediate use in distribution/demand centers and remote areas. • Coal is the primary energy source of South Africa and key driver of national CO 2 emissions. • Traditional coal gasification technologies are marked by high CO 2 emissions. • Coal plasma gasification technology is a viable option for low-carbon energy economy. • Hydrogen production via coal or coal/biomass plasma gasification technology leads to zero-carbon economy. • This immensely supports the drive towards attaining the sustainable development goals. [ABSTRACT FROM AUTHOR]

Biorenewable hydrogen is requisite to replace non-renewable hydrogen. Decarbonization is assured. Hydrogen demand is severely rising due to mitigating climate change and reducing fossil fuel dependency. Green Hydrogen from agro waste proposition makes bio-circular economy upcycling. The main objective of this study is to reinforce the hope of renewable, sustainable H 2 production from agro-waste. Initially, this paper shows the demand for green hydrogen, the sustainable availability of agro waste, and their capability to produce H 2. Insights into the gasification of agro waste about cellulose, hemicellulose, and lignin with conventional gasification. The effect of catalyst and supercritical gasification and their challenges is discussed. Most uniquely, other reviews highlight various aspirations behind agro-waste gasification to attain a strong business model, such as co-production, co-gasification, and CO 2 reforming with H2 yield. This review exhibits some main insight into various aspects of agro-waste gasification. H 2 from agrowaste gasification has high energy content (122 kJ/g) and high energy conversion efficiency in the range of 55–58 %, in addition to gaining the economic penalties of 2.2–2.5 net points for decarbonization. Agro waste is composed of lignocellulosic material that is relatively richer in hydrogen than fossil fuel resources. In SCWG, water is one of the natural solvents, which means feedstock effectively dissolves with water solvents. Intermittent density, low viscosity, and surface tension are nearly zero values due to SCW having no specific phase boundary, which enhances the gasification and substantially reduces tar formation during SCWG. Catalyst utilization enhances H 2 production. The present study comprehensively exhibits the role of catalyst and their supporter and promoter. Ni-based catalysts are mostly suggested for H2 production but fall into reusability issues. The main reason behind this is that Ni is inefficient in removing HCl, H 2 S, and total trace elements during gasification. Recently, low-cost and waste-to-wealth transformation aspects of biochar-based catalysts have gained attention. Renewable-assisted gasification significantly improves the energy and exergy of the system and suppresses the important concern of energy consumption during gasification. Renewable assisted and various aspiration incorporation into gasification is solidly recommended for future implementation based on energy, economic, and environmental benefits from them. Plastic and biomass are richer in hydrocarbon and oxygen, respectively; this synergistic effect has the potential to enhance the H 2 yield. From this study, PP plastic is mostly preferred for co-gasification with biomass. Compared to 100 wt% of biomass, the introduction of plastic slightly increased the coke formation, but the H 2 yield was improved. When the plastic mixture of 10 wt% increases coke deposition, however, significant coke deposition is not reported when 20 wt% of plastic concentration is not reported. Carbon capture via CO 2 inert gas supply enhances the H 2 yield, provides a route to carbon trade, and substantially contributes to GHG pollution mitigation. Agro-waste gasification is produced by a product that has the potential to be used in a wide range of applications due to its unique properties, such as large specific surface area, porosity, functional groups, high reliability, and minimum cost. Hopefully, this review will be an optic to the most appropriate green hydrogen production path for sustainable clean energy production and effective agro-waste management. • This review acts as an optic to the most appropriate green hydrogen production path. • Hydrogen separation, purification, and storage need more care. • Carbon dioxide reformation aids a carbon trading system and reduces environmental effect. • These research provide direction for energy nexuses that may be derived from agricultural waste. [ABSTRACT FROM AUTHOR]

The first part of the current study highlights the importance of developing a clean hydrogen supply chain (CHSC) in Iran to enhance energy security and contribute to global efforts towards sustainable energy transition. Depending on whether the focus is on domestic consumption or export of hydrogen, the study provides valuable insights into the prioritization of CHSC development pathways via multi-criteria decision-making tools (AHP, AHOP-TOPSIS, and AHP-VIKOR). The results show that for domestic hydrogen consumption (internal scenario), the best path of the supply chain includes blue hydrogen from steam methane reforming coupled with carbon capture and storage, H 2 -carriers (ammonia and methanol), natural gas grid for transportation and distribution, and industry sector as the end user. In the external scenario, however, the best path of the CHSC consists of green hydrogen production based on solar energy, and the other parts of the path include liquid hydrogen as the storage method, ship as the distribution and transportation, and industrial sector as the end user. By identifying the most suitable methods and technologies for each stage of the supply chain, this paper offers a comprehensive analysis that can guide decision-making in CHSC development. [ABSTRACT FROM AUTHOR]

Hydrogen is considered a truly clean energy source with great potential for replacing fossil fuels. However, the special physical and chemical properties of this source make large-scale, safe, and efficient storage challenging, thus limiting its widespread use. Consequently, an underground hydrogen storage system inspired by underground methane storage and CO 2 geological sequestration has been proposed, and it is increasingly becoming a focus of research. Depleted oil reservoirs are ideal sites for such systems. Nevertheless, research on these types of underground hydrogen storage systems is limited to a few feasibility assessments, and the hydrogen seepage laws in reservoirs with residual oil are not well understood. In this paper, a study was conducted involving mathematical modeling and numerical simulation of underground hydrogen storage, which was converted from the SSZ low-permeability depleted oil reservoir in Bohaiwan Basin, eastern China, to reveal the seepage patterns between hydrogen and complicated in situ fluids (oil, gas, and water). First, a comprehensive analysis was conducted using numerous rock samples and experimental data to identify the composition, genesis, and distribution patterns of the sandstone reservoir, detailing its internal pore structure and fluid distribution postdepletion characteristics. Then, the hydrogen seepage properties in the presence of oil films in the three main throat types of low-permeability sandstone were analyzed, and corresponding mathematical models of the different throats were established. Finally, a numerical simulation of underground hydrogen storage was conducted to assess the impacts of various parameters, such as injection speed, reservoir heterogeneity, and residual oil saturation, on hydrogen seepage. The planar and vertical diffusion patterns of hydrogen were clarified, and the key factors affecting the efficiency of underground hydrogen storage were analyzed, offering suggestions for the establishment of stable and efficient underground hydrogen storage systems. • Selection and description of typical low-permeability reservoirs for UHS. • Mathematical model establishment for hydrogen percolation in porous rock. • Numerical simulation of the storage process of hydrogen. • Percolation laws of hydrogen in rock porous. [ABSTRACT FROM AUTHOR]

This paper presents the preliminary design and thermodynamic analysis of hydropower and solar integrated e-fuel production system for a tea factory. In this regard, an integrated hydro-solar e-fuel production system has been developed, which is mainly able to produce e-methanol and green hydrogen. The system contains five main subsystems: i) Proton exchange membrane electrolyzer system, ii) CO 2 capture and storage system, iii) Methanol production system, iv) Photovoltaic system, and v) Penstock hydroelectric power plant. In terms of the general system operating principle, it is important to emphasize that the energy need of the system is supplied by solar power plant during the sunshine duration (the case 1) and provided by hydropower plant in the period when solar energy is not sufficient (the case 2). Considering the required assumptions, in the first step, preliminary design was performed, and in the second step, the energy and exergy analyzes were achieved, and in the final step, the effects of parameters such as CO 2 capture efficiency, methanol reactor conversion ratio, and environmental temperature on the system performance were parametrically investigated. Accordingly, in the case 1, the maximum energy and exergy efficiencies of the integrated e-fuel production system were respectively obtained to be 7.132% and 6.569% while, in the case 2, those were respectively calculated to be 39.44% and 42.36%. Moreover, approximately 235.9 tons of CO 2 emission in operation period of the tea factory considered in this work can be reduced by the integrated hydro-solar e-fuel production system that has a production capacity of 399.8 kg/h for methanol and 37.73 kg/h for hydrogen. It is expected that the integrated system concept may contribute to the researchers, system designers, policy makers, investors, and different enterprises for practical applications. • Hydropower and solar integrated e-fuel production system for a tea factory is proposed. • The preliminary design and thermodynamic analysis have been performed. • Thanks to the developed systems, 235.9 tons of CO 2 emissions can be reduced. • The maximum exergy efficiency of case-1 and case-2 are obtained to be 6.569% and 42.36%, respectively. [ABSTRACT FROM AUTHOR]

In continuation of the previous part, this paper comprehensively focuses on energy, exergy, exergo-economic, and environmental (4E) analyses of two prioritized clean hydrogen (H 2) supply chains pathways. The first scenario relies on domestic demand , involves blue H 2 production and storage using steam methane reforming coupled with carbon capture and storage through H 2 conversion to hydrogen carriers in liquid form (ammonia and methanol) aligned with the existing infrastructure. The second scenario involves green H 2 production from photovoltaic panels as the power source follows by storing H 2 in liquid form which is more suitable to export. The findings indicate that the blue H 2 system outperforms the green H 2 system in terms of energy and exergy, boasting 41.38% and 22.15% compared to 12.16% and 12.75%, respectively. However, when examining economic parameters, the blue H 2 system shows a total cost rate of 1976 US$/h, a net profit of $747.2 million (mn) at the end of its lifetime, and a payback period of approximately nine years. Conversely, the green H 2 system demonstrates economic indicators of a 125.2 $/h as a total cost rate, $1.26 billion (bn) net profit, and an 8.17 year payback period. Moreover, the production cost rates for blue and green H 2 are 1.32 $/kg and 2.55 $/kg, respectively; while the CO 2 emissions rate in the blue H 2 system is 10.71 kg/s. The green H 2 system prevents 19.84 kg/s of CO 2 emissions resulted a significant environmental cost reduction of 2.28 $/kg H 2. This analysis facilitates a thorough comparison of these two clean H 2 production and storage systems, offering insights for policymakers across performance, economic, and environmental dimensions. • A comprehensive 4E analysis was applied for the selected H 2 value chain scenarios. • Blue H 2 scenario is superior economically while environmentally the green one takes precedence. • Carbon credit makes the green H 2 scenario emerges frontrunner utilizing PV solar technology. • Methanol was recognized as the most cost-effective H 2 carrier for storage in Iran. [ABSTRACT FROM AUTHOR]

Business-as-usual (BAU) cement production is associated with a linear model that contributes significantly to global warming and is dependent on volatile energy markets. A novel circular model is proposed, by adding three power-to-gas system components to current production systems: a calcium-looping (CaL) CO 2 capture unit; water electrolysis for hydrogen and oxygen generation; and a methanation unit for synthetic natural gas (SNG) production. The paper presents the first analysis of the combined industrial-scale operation of these components in a closed loop, where the SNG fuels the cement kiln and the CaL unit, while the O 2 produced feeds it. The circular, hybrid, and BAU models are compared in three feasibility scenarios. It is concluded that the circular model outperforms the other alternatives environmentally, opening a potential pathway for the cement industry to achieve near net-zero CO 2 emissions, reduce energy dependence and improve economic efficiency. [Display omitted] • Innovative circular model proposed for carbon-neutral cement production. • Novel integration of CaL CO 2 capture, water electrolysis and methanation units. • Comparative techno-economic and environmental analysis conducted. • Circular model outperformed current and hybrid models. • Near net-zero CO 2 emissions and increased energy independence achieved. [ABSTRACT FROM AUTHOR]

• A review with over 300 references on the utilization of challenging ashes. • Metal and phosphorus recovery from different ashes was addressed. • The key beneficial properties of biomass and MSW ashes were identified. In line with the objectives of the circular economy, the conversion of waste streams to useful and valuable side streams is a central goal. Ash represents one of the main industrial side-products, and using ashes in other than the present landfilling applications is, therefore, a high priority. This paper reviews the properties and utilization of ashes of different biomass power plants and waste incinerations, with a focus on the past decade. Possibilities for ash utilization are of uttermost importance in terms of circular economy and disposal of landfills. However, considering its applicability, ash originating from the heat treatment of chemically complex fuels, such as biomass and waste poses several challenges such as high heavy metal content and the presence of toxic and/or corrosive species. Furthermore, the physical properties of the ash might limit its usability. Nevertheless, numerous studies addressing the utilization possibilities of challenging ash in various applications have been carried out over the past decade. This review, with over 300 references, surveys the field of research, focusing on the utilization of biomass and municipal solid waste (MSW) ashes. Also, metal and phosphorus recovery from different ashes is addressed. It can be concluded that the key beneficial properties of the ash types addressed in this review are based on their i) alkaline nature suitable for neutralization reactions, ii) high adsorption capabilities to be used in CO 2 capture and waste treatment, and iii) large surface area and appropriate chemical composition for the catalyst industry. Especially, ashes rich in Al 2 O 3 and SiO 2 have proven to be promising alternative catalysts in various industrial processes and as precursors for synthetic zeolites. [ABSTRACT FROM AUTHOR]

Aiming at the excessive power fluctuation of large-scale wind power plants as well as the consumption performance and economic benefits of wind power curtailment, this paper proposes a hybrid energy storage capacity configuration strategy for virtual power plants based on variable-ratio natural gas-hydrogen blending. Firstly, a natural gas-hydrogen blending virtual power plant architecture with the synergy of power-to-gas and carbon capture is established in terms of low-carbon performance, and then a natural gas-hydrogen blending capacity configuration with the synergy of carbon capture and power-to-gas is carried out for the architecture. Secondly, the mathematical modeling is carried out for the liquid storage carbon capture, power-to-gas, hydrogen storage, flywheel energy storage, hydrogen blending gas turbine and hydrogen blending gas boiler. Finally, the objective function of minimizing the cost of carbon trading and storage, the cost of startup and shutdown of coal-fired units and the cost of coal consumption, the cost of wind power curtailment, the cost of purchasing gas, the cost of power-to-gas, the cost of hydrogen blending, and the cost of hydrogen blending is proposed based on the modelings. After the linearization of the models, the Gurobi commercial solver was invoked through MATLAB software to solve the model, and five scenarios were set up for comparative analysis. The results further verified the effectiveness of the proposed strategy. • Empirical mode decomposition algorithm is used to achieve wind power decomposition. • Flywheel energy storage is configured to suppress the wind power. • In-depth analysis of hydrogen blending ratios improves economic benefits. [ABSTRACT FROM AUTHOR]

The transition to increasingly renewable electricity grids and the electrification of industrial processes are two recent developments promising to be potential solutions towards net zero in industrial production processes. Generally, grid electricity is perceived as a stable and reliable resource that can be accessed on demand. However, that is not always the case for large industrial users (100 MW+), and a key future challenge that must be overcome is the inherent uncertainty of the electricity supply by renewable sources, as well as in pricing. In methanol production, the concept of using electrolysis and CO2 capture is being explored as a way of replacing reforming to produce syngas for "green" methanol production. With the omission of the reforming process which supplies energy as steam for the process, there is now a need to electrify the affected downstream unit operations. Distillation is a key unit operation in chemical operations that consumes large amounts of energy for reboiler duty and holds the key to making on-specification AA-grade methanol, a precursor chemical. With the volatility of the electricity market, hence supply, these columns must be able to withstand a sudden large reboiler duty drop. This paper developed a novel process operations and control principle to allow for the flexible operation of a high-purity methanol distillation column in volatile energy markets. At its core is the concept of using a distillation column as a "process battery". Results obtained from a validated process simulation show that the novel "process battery" operations principle can withstand a supply-side change as great as 75% within a time span of 5 min without breaking complex quality and performance specifications of the column. This control philosophy is a major departure from the traditional process control and operating regimes that are focused on maintaining steady operations under all conditions. • Novel control philosophy developed for flexible operation of high-purity methanol distillation in volatile energy markets. • A major change from traditional operations and control focused on maintaining steady operations under all conditions. • The concept of using a distillation column as a "process battery" is defined. • Validated process simulation results show the strategy withstands large supply-side changes without breaking specifications. [ABSTRACT FROM AUTHOR]

Hydrogen is expected to be a game changer in the fight against climate change, being able to support the clean energy transition through a variety of roles: decarbonizing different hard-to-abate industrial sectors (such as steel, cement production) and transport (in long haul vehicles, maritime transport, and aviation), direct use as a fuel, chemical feedstock or in the form of synthetic fuels, and providing the ability to integrate with hybrid energy systems and renewables, enhancing energy storage and tapping the full potential of renewable energy sources. As a consequence, a substantial expansion in hydrogen production, due to rise in the demand, is expected by 2050, with all the generation coming from zero-carbon processes (electrolysis/thermochemical cycles using clean electricity and heat) or from a low-carbon production process using steam methane reforming with carbon capture and storage. Nuclear energy can be capitalized on both electricity and heat to provide a clean and reliable source of hydrogen through various processes. There are currently various demonstration projects undergoing in several countries to showcase the use of nuclear energy to produce clean hydrogen, considering both the current reactor fleet and advanced reactors. This paper provides an overview of these projects, giving an insight on the potential use of nuclear energy for hydrogen production and the current status of existing projects. It also highlights the activities of the International Atomic Energy Agency on technical and economic assessment of hydrogen production using nuclear energy for near term deployment. • Hydrogen is anticipated to be a game-changer in the fight against climate change. • Nuclear energy is positioned favourably to serve the developing hydrogen economy. • A single 1000 MW nuclear reactor could produce more than 200,000 t of H2 per year. • Several countries are considering nuclear hydrogen demonstration projects. • The IAEA has multiple resources available for nuclear hydrogen production. [ABSTRACT FROM AUTHOR]

Hydrogen is a versatile energy carrier and storage medium that is expected to have a key role in the energy transition, as it can be employed in a variety of applications. Hydrogen can be produced from different feedstocks and using different processes. Based on the production technology used, hydrogen is conventionally identified by a color. In this work, we compare different hydrogen generation processes: (i) green hydrogen, obtained by electrolysis of water using electricity from floating photovoltaic platforms, (ii) grid hydrogen, also obtained by electrolysis but using grid electricity, (iii) grey hydrogen, produced from natural gas using steam reforming and (iv) blue hydrogen, which is similar to grey hydrogen, but uses hot potassium carbonate as the solvent for carbon capture and storage. The paper considers the production of hydrogen necessary for 2 trips per day of a medium size ferryboat to navigate full electric for 7 h in the Adriatic Sea. Process simulation is applied to solve material and energy balances for each process investigated, as well as for the evaluation of capital and operating costs. Process simulation outcomes are then used to estimate three key performance indicators focused on energetic, economic, and environmental sustainability issues: the energy return on energy invested, the levelized cost of hydrogen, and the life cycle assessment. The energy indicator for grid and green hydrogen has a value of 13.39–14.29, versus a value of 4.59–5.48 for other hydrogen production methods from natural gas. The cost for green hydrogen is slightly higher (8.76) compared to the blue hydrogen (5.50) however green hydrogen has a much lower impact to the environment. Considering the combined results obtained by all the indicators, it is concluded that the most sustainable hydrogen production method is green hydrogen. • Process simulation provides data to design hydrogen production processes. • Green hydrogen has larger return of energy invested than natural gas-based routes. • Floating photovoltaic production is competitive for green hydrogen production. • Life cycle assessment shows excellent results for green hydrogen. • Indicators are evaluated for hydrogen use in the maritime industry. [ABSTRACT FROM AUTHOR]

Post-combustion carbon dioxide (CO 2) capture via flue gas is an advanced technology for mitigating greenhouse gas emissions. Its significance lies in the potential for retrofitting this technology to the current inventory of coal-fired power plants. This review paper aims to present the state of art in the technologies of adsorption techniques in post-combustion technologies to capture CO 2 from flue gas streams. These techniques have demonstrated numerous potential benefits when compared to conventional CO 2 capture methods that utilize aqueous amine solvents. Additionally, this overview presents the development in the field of novel solid sorbents for post-combustion CO 2 capture, focusing on their enhanced performance and favorable economic feasibility. The promising potential of mesoporous silica has been recognized to evaluate the enhanced capacity of CO 2 adsorption offered by these materials. Several research studies have reported different techniques of functionalizing porous silica by introducing amine groups. Various methods of functionalization for mesoporous silica, such as impregnation, grafting, and hybrid approaches, have been examined to improve the efficiency of the sorbents. Furthermore, this work summarises the research challenges with porous silica materials and indicates the possibilities for future studies to improve post-combustion carbon. [ABSTRACT FROM AUTHOR]

Oilfield wastewater with high moisture content can be efficiently treated by supercritical water gasification (SCWG) technology to produce hydrogen. This paper conducted a thermodynamic and environmental analysis of the oilfield wastewater SCWG system to provide optimization strategies. The waste heat utilization technology can enhance the heat integration of the system to reduce the exergy destruction and increase the H 2 yield. Sensitivity analysis showed that a ratio of preheating water to emulsion 3 can promote water-sensitive reactions to produce H 2 and save the H 2 needed to maintain the energetically self-sufficient system. Low system pressures, high feedstock preheating temperatures, and low oxidation reactor temperatures can reduce system energy destruction to obtain high H 2 yield and system efficiency. Meantime, the developed SCWG system has the potential to achieve natural enrichment of greenhouse gases after the H 2 separation has been completed. The use of waste heat utilization technology and carbon capture and storage (CCS) technology is expected to increase system efficiency to 53.43 % and reduce global warming potential (GWP) of 5.52 kg CO 2 -eq/kg H 2. This work would be of great value to the process design and optimization for the SCWG system of oilfield wastewater. [Display omitted] • The process of supercritical water gasification of oilfield wastewater was simulated. • Optimization strategies were given by thermodynamic and environmental analysis. • Operational details were revealed by comprehensive sensitivity analysis. • The exergy efficiency of 53.43 % were obtained. • Global Warming Potential decreased to 5.52 kg CO 2 -eq/kg H 2 with CCS. [ABSTRACT FROM AUTHOR]

This study investigates the potential of natural gas-based plants designed to produce blue hydrogen and decarbonized electric power, conceived to operate flexibly depending on the electricity price. This paper considers plants based on fired-tubular reforming (FTR) and auto-thermal reforming (ATR) technologies, with MDEA-based pre-combustion CO 2 capture process and partial electrification of the reformer, designed to achieve CO 2 capture efficiency higher than 95 %. Heat and mass balances for the chemical and power island are evaluated at both full and part load to define the corresponding operating maps. With pre-combustion CO 2 capture only, FTR plants can achieve CO 2 capture rates higher than 90 %, H 2 production efficiency of 73–74 % and power generation efficiency of around 47 %. Reformer electrification allows increasing overall capture efficiency to 95 %. Plants based on ATR can approach 95 % capture efficiency without electrification and achieve H 2 efficiency similar to FTR but higher electric efficiency, close to 51 %. An economic analysis is performed to assess profitability of the plants under electricity price scenarios with different penetration of renewables. The economic analysis shows that flexible plants may be profitable in future scenarios with high penetration of renewables and high price variance, resulting in IRR around 10–17 % for hydrogen selling prices of 2.0–2.5 €/kg, natural gas price of 9 €/GJ and carbon tax of 100 €/t CO2. [Display omitted] • Techno-economic study of low-emission H 2 & power plants with CO 2 capture. • Fired tubular reformers and autothermal reformers compared. • Reformer electrification increases capture rate and gives operational flexibility. • 71.3–75.2 % hydrogen production efficiency and 47.4–50.9 % electric efficiency estimated. • IRR 10–17 % in future high wind electricity market with hydrogen prices of 2.0–2.5 €/kg. [ABSTRACT FROM AUTHOR]

The gas adsorption/desorption-induced coal deformation effect is a significant factor governing the evolution of coalbed permeability. Current theoretical investigations typically coal bulk and fracture deformation induced by gas are equivalent, neglecting the matrix-fracture interactions. Based on internal adsorption stress, this paper proposes Internal Differential Strain Coefficient (IDSC) to quantitatively characterize the relationship between coal bulk and fracture strain under equilibrium conditions. Coupling this coefficient constructs a binary gas permeability evolution model considering matrix-fracture interactions. Through numerical simulations of CO 2 -ECBM processes under various internal differential strain circumstances using this model, dynamic evolution patterns of diverse parameters are obtained. The research findings indicate that along the direction of CO 2 injection, matrix-fracture interactions exhibit a complex trend of initially increasing, then decreasing and then increasing, and the increase in internal differential strain levels results in a downward trend in permeability peak. Additionally, the evolutionary characteristics of CH 4 recovery and cumulative CO 2 storage rising with increasing internal differential strain levels were obtained on time scales using a fixed-point monitoring methodology. Inspired by the aforementioned laws, this paper discusses the macroscopic influence of burial depth on the effects of internal differential strain, providing new theoretical support for CO 2 sequestration injection methods in deep coal seams. • A coefficient capable of quantitatively analyzing the internal differential strain in the CO 2 -ECBM process is proposed. • Based on IDSC, a model describing the evolution of coal seam permeability in CO 2 -ECBM process is established. • Analyzed the influence of internal differential strain on the permeability of coal beds in the CO 2 -ECBM process. • Analyzed the influence of internal differential strain characteristics on CO 2 injection capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Calcium looping (CaL) captures carbon dioxide and waste heat from industrial flue gases. • Methane dry reforming (MDR) produces blue hydrogen with high thermal energy penalty. • Synergy of MDR and CaL shows huge potentials for industry decarbonisation. • Major challenges are catalyst deactivation, sorbent sintering and system integration. Industry is the biggest sector of energy consumption and greenhouse gas emissions, whose decarbonisation is essential to achieve the Sustainable Development Goals. Carbon capture, energy efficiency improvement and hydrogen are among the main strategies for industrial decarbonization. However, novel approaches are needed to address the key requirements and differences between sectors to ensure they can work together to well integrate industrial decarbonisation with heat, CO 2 and hydrogen. The emerging Calcium Looping (CaL) is attracting interest in designing CO 2 -involved chemical processes for heat capture and storage. The reversibility, relatively high-temperature (600 to 900 °C) and high energy capacity output, as well as carbon capture function, make CaL well-fit for CO 2 capture and utilisation and waste heat recovery from industrial flue gases. Meanwhile, methane dry reforming (MDR) is a promising technology to produce blue hydrogen via the consumption of two major greenhouse gases, i.e., CO 2 and CH 4. It has great potential to combine the two technologies to achieve in-situ CO 2 utilization with multiple benefits. In this paper, progresses on the reaction conditions and performance of CaL for CO 2 capture and industrial waste heat recovery, as well as MDR were screened. Secondly, recent approaches to CaL-MDR synergy have been reviewed to identify the advantages. The major challenges in such a synergistic process include MDR catalyst deactivation, CaL sorbents sintering and system integration. Thirdly, the paper outlooks future work to explore a rational design of a multi-function system for the proposed synergistic process. [ABSTRACT FROM AUTHOR]

CO 2 sequestration has proven to be an attractive way to combat global warming. However, due to the corrosive nature of CO 2 , chemical reactions between CO 2 and the host rock can happen after the injection. This study reviews the current state of knowledge about chemical reactions and their effects on the mineralogy, structure, mechanical, deformation, and transport properties of different types of rocks from research papers published in 2004–2024. In addition to drawing a comprehensive picture of the research that has been done on the subject and the gaps that need to be filled, this review combined the data from the papers to introduce the relationships between exposure conditions (CO 2 pressure, exposure duration, and temperature) and mineralogy, strength, and elastic properties, and permeability of multiple types of rocks. Results showed that some minerals like quartz are not affected by CO 2 while others like carbonates can easily be dissolved. Datapoints from various papers showed a negative effect of CO 2 pressure and exposure duration, and a positive effect of temperature on the strength properties of rocks. An increase in permeability was another consequence of CO 2 treatment in most cases. This study is one of the first works to gather data from multiple sources in developing relationships between CO 2 treatment conditions and the strength properties of rocks. Results will potentially improve understanding and prediction of the effect of CO 2 on the properties and behavior of rocks. [Display omitted] • Quartz, unlike carbonates, is not impacted by CO 2. • Dissolution/precipitation of minerals leads to increase/decrease in pore volume. • The compressive strength mostly decreases with an increase in CO 2 pressure. • Bulk and elastic moduli of rocks decrease after CO 2 treatment. • CO 2 increases the permeability of most rocks. [ABSTRACT FROM AUTHOR]

• Published Vex data in Table 5 and in Figure 2a are not the same. • Published Redlich-Kister equation does not back-calculated Vex values reported in Table 5. • Published Redlich-Kister equation does not back-calculated Vex values depicted in Figure 2a. • Inconsistencies also noted between tabulated and graphed values of Δ η and Δ G *E. A polemic is given regarding the volumetric properties that Wang and coworkers reported in their published paper. The tabulated excess molar volumes, Vex , reported by the authors are not the same values as graphically depicted in the paper. Our analysis of the experimental data indicated that the tabulated were likely calculated assuming a ternary system, while the graphically depicted values were likely calculated using a pseudo-binary system treatment. Similar inconsistences were noted between several of the tabulated and graphed viscometric properties in the published paper. [ABSTRACT FROM AUTHOR]

Geological carbon storage and sequestration (GCS), a key method within carbon capture and sequestration (CCS), is globally recognized as an effective strategy to reduce atmospheric carbon dioxide (CO 2) levels and combat the greenhouse effect. However, discrepancies between projected and actual storage capacities, especially in large-scale CO 2 storage, have raised concerns among stakeholders regarding potential overestimations. This paper reviews the definitions and methods used to estimate storage capacity, highlighting variations and providing a practical guide for predictions while suggesting directions for future research. We discuss numerous analytical and numerical models that account for dynamic constraints such as safety considerations, trapping mechanisms, and reservoir performance, primarily focusing on local scales. These models enhance the accuracy of capacity estimations over conventional static models by quantifying CO 2 storage capacity both spatially and temporally. Additionally, this review underscores the need for sophisticated evaluations of large-scale storage. We introduce two pivotal tools designed for basin-scale capacity estimation and discuss the challenges associated with expanding dynamic capacity assessments to larger scales. In conclusion, the paper explores the burgeoning use of machine learning-based models, advocating for future research efforts to leverage machine learning in developing integrated tools that offer more comprehensive and precise capacity estimations for GCS. • Reviews CO2 storage capacity definitions, noting the discrepancies. • Dynamic capacity: safety, trapping, reservoir performance limits beyond static. • Reviews models, uncertainties and influencing factors for capacity estimation. • Focusing on large-scale storage, introduces two efficient estimation tools. • Addresses needs, challenges and techniques of scaling up dynamic capacity. [ABSTRACT FROM AUTHOR]

Active methods for promoting gas hydrate formation, such as agitation, bubbling, and spraying, can lead to increased energy consumption and safety risks. Conversely, studies exploring chemical additives have been extensively reviewed, revealing that these methods often come with certain adverse effects, including reduced gas selectivity, increased mass transfer resistance and shortened lifespan of chemicals involved. However, these adverse effects could be potentially mitigated by using passive methods, which are promising to improve the safety, viability, scalability and lifespan of hydrate-based carbon capture. In this current review paper, passive methods refer to alterations within gas hydrate systems that stimulate hydrate formation without relying on non-mechanical or non-chemical techniques. These passive approaches encompass nano-confinement, surface treatment, suspended nanoparticles, and distributed hydrate systems. The promotion mechanisms, key features, limitations, and challenges associated with these passive methods are summarised in this paper, which provides guidance for the design of CO 2 hydrate reactors for effective carbon capture. • Four categories of passive methods for enhancing gas hydrate formation were reviewed. • Promotion mechanisms, features, and limitations of each method were summarised. • Overarching design guidance for each passive technology was provided. [ABSTRACT FROM AUTHOR]

Blue carbon, a concept that emerged in the last decade, has received increasing attention in recent years. The development of blue carbon as a nature-based solution is crucial to global climate governance, biodiversity conservation, and restoration of fishery resources. This study utilized CiteSpace visualization software to conduct bibliometric and systematic analyses of 3474 papers retrieved from the Web of Science Core Collection in 2003–2022, depicting a comprehensive framework of international research on blue carbon, exploring hotspots and trends, and proposing future directions and implications for ocean and coastal management. Overall, blue carbon research has experienced the early exploration period (2003–2007) based on scientific concepts, the development period (2008–2015) of research on carbon sequestration mechanisms and functions of different organisms and ecosystems, and the outbreak period (2016–2022) of carbon sink system quantification and management based on model prediction. Co-authorship analysis indicated that blue carbon research collaborates well across intuitions and countries, while collaboration among authors needs to be strengthened. Thematic evolution and hotspot analysis based on cited references and keywords revealed that coastal wetlands, especially mangroves, are a popular research theme, and the functional protection and development of management strategies for coastal ecosystems are major current research hotspots. In addition, it emphasized the need to focus on the protection, restoration and creation of blue carbon ecosystems (BCEs), develop sustainable marine ranching to promote blue carbon trading, explore more potential emerging blue carbon, and strengthen the management of blue carbon from the social level in the future. This paper combines traditional bibliometric review with modern visual analysis software to carry out network metrics, clustering and visualization of the blue carbon thematic literature from multiple perspectives, which reflects its novelty. It provides the latest, in-depth and comprehensive insights into blue carbon research that will serve as valuable reference for relevant scholars, managers and governments. [Display omitted] • Blue carbon field has experienced exploration, development and outbreak periods. • Blue carbon research is well-collaborated across institutions and countries. • Coastal wetlands, especially mangroves, have been a popular central research area. • Protection and management of coastal ecosystems are new hotspots in research. • Propose ocean and coastal management implications for realizing the potential of blue carbon. [ABSTRACT FROM AUTHOR]

Residential green spaces are an integral part of urban green infrastructure and its role in climate change adaptation and mitigation. Various urban typologies and changing planning practices affect the amount and structure of residential greenery, which has a direct impact on climate benefits. While urban green and its climate benefits have received increasing attention, there is still limited knowledge on how changing planning practices and related urban typologies impact residential vegetation and its capacity to deliver climate benefits. This paper aims to address this gap by determining the impact of planning practices on residential vegetation, focussing specifically on climate mitigation and adaptation. With the case study of Helsinki, characterized by a high share of green areas, the paper first examines how construction year and urban density affect the amount and structure of vegetation on residential properties. Second, it estimates the carbon sequestration and summer temperatures in the present-day climate. The paper applies spatial modelling and regression analysis to estimate the impact of construction year on the studied dependent variables, while controlling density via gross floor area of buildings. The study demonstrates that the average amount of residential vegetation, as measured using canopy and vegetation cover, has declined 15 percentage points from the 1970 s to early 2010 s and the canopy to low vegetation ratio has decreased constantly over the periods studied. The decline of the canopy cover in particular has reduced the climate benefits of residential vegetation. The paper highlights the significant impact of gross floor area and planning practices on urban vegetation cover and the climate benefits it provides. It also stresses the importance of ensuring sufficient tree cover and permeable surfaces in cities with progressive climate mitigation agenda throughout the chain of urban planning, construction, and subsequent property management stages. [Display omitted] • Residential areas are a vital but understudied part of urban green infrastructure. • The amount of residential vegetation has diminished since the late 1970 s • The decline in canopy cover has reduced the climate benefits of residential areas. • Density and spatial patterns affect the climate benefits of residential vegetation. • Climate-wise, residential areas require sufficient vegetated and permeable surfaces. [ABSTRACT FROM AUTHOR]

Many nations have pledged to reach carbon neutrality by 2050. Embarking on the decarbonization journey, they posited geological carbon storage (GCS) as a pivotal technology within the carbon capture, utilization, and storage (CCUS) framework. The CCUS chain operates to reduce "hard-to-abate" emissions at key sectors by capturing carbon dioxide (CO 2), reusing it, transporting it, or disposing of it via injection into underground geological formations for permanent storage. Despite the global success of GCS ventures, mainly driven by the oil and gas industry, GCS initiatives are still in their early stages in several developing countries. In Brazil, for instance, a full setup covering precise storage capacity databases, potential CCUS clusters, national regulatory structure, and auxiliary computer-aided engineering is underway. Intended to push the frontier in the latter subject, this paper introduces mathematical models for qualifying underground CO 2 storage sites. Our research explores a family of multivariate functionals endowed with underlying reservoir features and distinct weighting functions, thus envisioning two primary objectives. Firstly, it clarifies non-linear interactions between rock and fluid properties using quality indicators. Secondly, it evaluates geographical regions considering structural traps/caprocks settings. Backed by the Matlab Reservoir Simulation Toolbox (MRST) capabilities, the methodology is a subsidiary resource for identifying suitable injection and storage sites. A case study using the UNISIM-I-D model generated dozens of volumetric quality maps that point to unique potential storage sites. Numerical simulation experiments of injection comparing legacy and novel wells reveal storage surpluses improved by up to 50%. The paper seeks to establish foundational knowledge in GCS efficiency for general underground settings. One expects that these outcomes leverage well-repurposing perspectives and stimulate field appraisal actions to scale up GCS projects both in Brazil and worldwide. • Introduction of a family of mathematical functionals for site qualification. • Trap analysis and supercritical gas injection over a Brazilian offshore reservoir model. • Comparison of storage surplus in theoretically-proposed and legacy well locations. [ABSTRACT FROM AUTHOR]

• The government's clean electricity subsidy and carbon utilization subsidy have pushed the timing of CCS retrofitting significantly forward, but the initial investment subsidy has little impact on it. • Under the cooperation mode of coal-fired power plants and oilfield enterprises, the optimal cost-sharing ratio of the initial investment for coal-fired power plants is about 0.4 to promote both sides to reach cooperation faster. • The carbon tax policy effectively propels the development of CCS-EOR technology. When the carbon tax rises from 30 CNY/t to 120CNY/t, power plants will conduct CCS retrofitting investment two years in advance. Carbon capture and storage with enhanced oil recovery (CCS-EOR) technology plays a crucial role in achieving dual carbon targets in China. And the rapid diffusion of technology requires collaboration among various stakeholders involved in industrial chain of CCS-EOR project and then it will cause conflict of interest among the participants. In order to solve the problem existing in CCS-EOR promotion and propel the rapid deployment of low-carbon technology in China, the paper constructs a tripartite evolutionary game model by incorporating the strategic choices of coal-fired power plants, oilfield enterprises and governments into the framework, explores the respective dynamic evolutionary path of three parties and analyzes the impact of each parameter change on the system evolution results Through the numerical simulation, the paper identifies the optimal evolutionary path to spur the application of CCS-EOR and determine their strategy choices of three involved subjects in the game framework. Based on the sensitivity analysis, results are given as follows: (1) The government's clean electricity subsidy and carbon utilization subsidy have pushed the timing of CCS retrofitting significantly forward, but the initial investment subsidy has little impact on it; (2) Under the cooperation mode of coal-fired power plants and oilfield enterprises, the optimal cost-sharing ratio of the initial investment for coal-fired power plants is about 0.4 to promote both sides to reach cooperation faster. Once it exceeds 0.4, the probability of cooperation between them will be significantly reduced; (3) The carbon tax policy effectively propels the development of CCS-EOR technology. When the carbon tax rises from 30 CNY/t to 120CNY/t, power plants will conduct CCS retrofitting investment two years in advance. [ABSTRACT FROM AUTHOR]

The dependence on fossil fuels is the primary cause of the increased carbon dioxide emissions into the atmosphere that have resulted in drastic global climate changes due to greenhouse effects and associated global warming. Carbon capture and sequestration (CCS) is a multidisciplinary technology that is gaining momentum in the quest to mitigate the effects of CO 2 emissions. In this paper, we review the current status of research pertinent to the geomechanical modeling of CO 2 sequestration and highlight the key research accomplishments, unresolved problems, and pending challenges and opportunities. The paper begins with a brief overview of the geological sequestration process and then proceeds to review the main aspects of geomechanical modeling, including different numerical methods for modeling the reservoir pressure, ground uplift due to pressure buildup, caprock fault reactivation, carbon dioxide leakage, and induced seismicity. The effects of the number and distribution of injection and production wells on the pore pressure buildup are discussed. Finally, a topical overview of monitoring techniques for stored carbon dioxide is presented. [Display omitted] • Geomechanical modeling of sequestration sites is essential to ensure stability and safety of the deep geological reservoirs. • The effectiveness of a CO 2 storage geomechanical model is mainly dependent on the choice of numerical method. • Geomechanical modeling monitors the injection induced stress changes, reactivation of existing faults, and ground uplift. • The injected CO 2 should be monitored using various satellite, surface and subsurface techniques to avoid any possible leakage. [ABSTRACT FROM AUTHOR]

The core of the energy transformation under the carbon-neutral vision is the gradual replacement of high-carbon energy by zero-carbon and low-carbon energy. However, the large-scale deployment of clean energy technology in turn relies on key minerals such as copper, aluminum, zinc, and nickel. Based on this, this paper conducts research on the demand for key minerals in clean energy transition and the role of key minerals in clean energy transition. In particular, this paper calculated the demand for mineral supply for China's carbon neutrality target, and the impact of some mineral resource constraints on the carbon neutrality path. Relevant results can provide a decision-making basis for the future development and utilization of key mineral resources, as well as the implementation of future carbon-neutral goals. • We evaluate the impact of crucial mineral resource on the carbon neutrality path. • Copper's availability greatly affects the adoption of new energy technologies. • Limited resources hinder early carbon capture and storage development. • Negative emission technologies are necessary for China's carbon neutrality. [ABSTRACT FROM AUTHOR]

[Display omitted] • The typical kinetics and reaction mechanism of fly ash carbonation were described. • Accelerated CO 2 mineralization technology was summarized in terms of reactor design and pretreatment. • The mechanism of different types of chemical additives to accelerate the carbonation of fly ash was summarized. • Carbonation products obtained from different pathways and utilization were analyzed and compared. • Scale-up applications and main challenges of fly ash carbonation technology were summarized and prospected. As global climate issues become increasingly pronounced, human society is confronting unprecedented environmental challenges. The escalating anthropogenic carbon dioxide (CO 2) emissions have intensified the global warming process, resulting in a cascade of environmental degradation issues. CO 2 mineralization stands out as a highly promising approach for carbon capture, utilization, and storage (CCUS) to mitigate global warming. This paper provides a comprehensive review of the current state of accelerated CO 2 mineralization using typical industrial solid waste, "fly ash," as a raw material. The article commences by introducing the physicochemical properties of fly ash, and various typical CO 2 mineralization kinetic models. Subsequently, it provides a comprehensive evaluation of accelerated CO 2 mineralization pathways, encompassing reactor design (reactor types, operational parameter design, etc.), fly ash activation pretreatment (milling, calcination, etc.), and chemical additives (organic amines, amino acid salts, sodium salts, ammonium salts, etc.). A summarization and analysis of the integrated utilization of products obtained through different mineralization pathways are presented. Finally, the paper discusses the scale-up applications and potential challenges faced by reported fly ash carbonation, emphasizing that research on accelerated solid waste carbonation is an inevitable process for the industrial application of this technology. We hope that this review will contribute to advancing the industrialization of CO 2 sequestration through mineralization of solid waste. [ABSTRACT FROM AUTHOR]

Chemical Looping Combustion (CLC) is a carbon capture technology that uses an oxygen carrier to transfer the oxidizing agent to the fuel for combustion. This study used different machine learning algorithms, Artificial neural network and Response surface methodology to estimate the surface region process performance and optimize the process condition for the CLC of different solid fuels waste paper, plastic waste, and sugarcane bagasse blends. Based on the combustion efficiency, CO 2 yield and CO 2 capture efficiency responses, A high performance correlation (R2 > 0.8) was obtained for all the combustion parameters analyzed. The perturbation plot derived from the RSM analysis indicated that the most significant input parameters include the steam to fixed carbon, blend ratio and the fuel reaction temperature. The CLC process was optimized using RSM. For blends of SCB/WP, the best operating conditions were found to be 800 °C, a solid flow rate of 197.7 kg/h, an oxygen carrier to fuel ratio of 1.1, a steam to fixed carbon ratio of 2.16, and a blend ratio of 1. Similarly, for blends of SCB/PW, the optimal operating conditions were 800 °C, a solid flow rate of 199.4 kg/h, an oxygen carrier to fuel ratio of 1.3, steam to fixed carbon ratio of 2, and a blend ratio of 0.3. The optimum combustion performance was found to be 0.98, 0.78, and 0.96 for SCB/WP and 0.99, 0.62, and 0.96 for SCB/PW, respectively. • The process performance of the CLC of MSW/biomass blend was compared using ANN and RSM. • The optimal blend ratios for SCB/WP and SCB/PW blends were 1 (25% WP) and 0.3 (42.5% PW). • The combustion performance of the WP improved by 6.2% and 3.5% in terms of combustion efficiency and CO 2 yield, respectively. • The most significant input factors were discovered to be the blend of fuels ratio and the steam to fixed carbon ratio. [ABSTRACT FROM AUTHOR]

Biomass direct-fired power plant integrated with carbon capture system can achieve negative CO 2 emission during the power generation, which provides an important technology pathway for the transformation of energy system towards carbon neutrality. Understanding the economic competitiveness and CO 2 reduction potential of the plant, and identifying the optimal operating mode are the key to fully exert the advantages of the technology. For this reason, this paper develops life cycle economic and CO 2 emission assessment models for the biomass direct-fired circulating fluidized bed boiler power plant (BCFBP) integrated with solvent-based post-combustion carbon capture (PCC) system. The levelized cost and CO 2 emission of energy indexes are then applied to evaluate the performance of the BCFBP-PCC system. Based on the life cycle assessment, a novel economy and CO 2 reduction dual-objective operating optimization approach is proposed for the BCFBP-PCC to find the optimal hourly power generation and CO 2 capture level of the plant under given market conditions. The static investment payback period is employed as a constraint in the optimization to narrow down the range of the solution set and provide clearer guidance for system operation. This paper provides the first work pioneered the economic and negative carbon operation optimization of the BCFBP-PCC system. [ABSTRACT FROM AUTHOR]

In recent years, there has been a notable surge in focus on the mitigation of carbon emissions, mostly motivated by the urgent concern about global warming and its adverse impacts on the Earth's climate. Power-to-gas (PtG) systems have emerged as a promising technological solution in the pursuit of mitigating carbon emissions. This paper presents a mathematical modeling framework that aims to accurately represent the power-to-gas system integrated with wind power plants while taking into account the technological constraints of the system in practical scenarios. To analyze the proposed system under the stresses, worst situations caused by existing uncertain parameters, especially wind power, is modeled using a risk modeling technique called downside risk constraints (DRC). The DRC endeavors to mitigate the likelihood of situations resulting in significant stresses by incorporating an expected downside risk into the proposed framework. This paper will provide a number of conservative tactics to be employed in the decision-making process under the realizations of uncertainties. These tactics, including strategic operational control strategies, provide a structured approach for decision-making under uncertain conditions. By incorporating downside risk constraints, the framework enables conservative decision-making that prioritizes mitigating potential losses and minimizing the operational risk within scheduling horizon of proposed PtG facility. The findings demonstrate that the implementation of PtG technology has the potential to yield a substantial reduction in external energy consumption, namely by 39.1 %. Additionally, it has been seen that PtG may effectively mitigate carbon emissions, resulting in a decrease of 38.9 %. The utilization of PtG technology and gas storage will result in a substantial reduction in wind curtailment, ultimately leading to a near elimination of curtailment. Further study is conducted on the model in order to explore the benefits of carbon and methane storage, as supported by the results obtained. [ABSTRACT FROM AUTHOR]

With the increasing severity of global warming, the goal of carbon sequestration and emission reduction in various industries has become an important responsibility for sustainable development. As an important part of carbon sink, the improvement of net carbon efficiency in the plantations industry will make a great contribution to the realization of the "double carbon" target in agriculture. However, there are large spatial and temporal differences in the net carbon efficiency of the plantations sector in various provinces, and there is still a large scope for increasing carbon sink and reducing carbon emission. In this paper, we have analyzed spatial and temporal trends in the net carbon sink efficiency of the plantations' production processes in 31 provinces in China (excluding Hong Kong, Macao and Taiwan) from 2000 to 2020. On this basis, we have analyzed the influencing factors of net carbon efficiency in the plantations' production process through an extended Kaya constant equation. Through the geographically and temporally weighted regression model, we explore the spatio-temporal heterogeneity of the influencing factors, and further analyze the driving and restraining factors of net carbon efficiency in plantations' production process, in order to propose appropriate countermeasures. The study shows that: (1) The net carbon efficiency of plantations sector in China increase between 2000 and 2020, and the development of net carbon efficiency is uneven across regions. (2) The geographic center of net carbon efficiency of China's plantations industry shift from the northeast to the southwest and is consistent with the migration direction of agricultural inputs. (3) The influencing factors of net carbon efficiency in the plantations sector show large regional differences, and can be specifically divided into four major types of zones. In this regard, this paper provides more appropriate countermeasure suggestions for increasing carbon sink and reducing carbon emission in each zone, with a view to achieving the goal of double carbon in agriculture with practical significance. • Net carbon efficiency is a new objective indicator to measure the carbon sink level of cropland. • Cultivated land carbon sink capacity is closely related to agricultural inputs. • Regional differences in the factors influencing net carbon efficiency. [ABSTRACT FROM AUTHOR]

• Step-by-step procedure to develop the tabulation and map component of UIC class VI permit. • Qualitative risk assessment methodology for all types of wells within AoR penetrating the confining zones. • Highlights the need for crossflow modelling of CO 2 leakage through improperly plugged wells. • Generalized categorization of legacy wells based on geologic penetrations and protections. Carbon Capture & Storage (CCS) refers to capturing the anthropogenic carbon dioxide (CO 2) at a source followed by injecting and storing it safely in the subsurface. The success of the CCS projects therefore heavily relies on how efficiently the confining zones (containment seals) prevent migration of the CO 2 to the surface and/or to the underground sources of drinking water (USDW) through leakage pathways. CCS projects requires drilling of Underground Injection Control (UIC) Class VI wells for permanent storage of CO 2 in subsurface. Detailed information of all the wells within the Area of Review (AoR) is needed to develop the map and tabulation components of the Class VI well permit application. This paper discusses the generic process that can be used by permit applicants to develop the dataset necessary for preparing the map and tabulation components of the Class VI permit application and perform qualitative risk assessment of all the wells within the AoR. This methodology directs the corrective action plans as well as monitoring plans to some extent. Results of the application of the newly developed methodology for wells in Illinois basin is discussed in detail. This methodology can be applied to all wells including orphaned wells, abandoned wells, active oil and gas wells, stratigraphic wells, disposal wells, etc. This methodology generalized categorization of legacy wells that will help in easier comparison of different CCS projects across the globe. The qualitative risk assessment methodology discussed in this paper is a good starting point for developing crossflow modeling. [ABSTRACT FROM AUTHOR]

The escalating global warming has intensified concerns about climate change and prompted a swift shift towards worldwide carbon neutrality and a sustainable future. Among various carbon capture, utilization, and storage technologies, mineral carbonation enables the transformation of waste materials into valuable construction resources while mitigating their adverse impacts on the environment and public health. During the past two decades, mineral carbonation has found widespread application in carbon sequestration, primarily employing industrial by-products, notably those generated within the iron and steel sector. The inherent properties of these by-products, characterized by alkalinity, reactivity for carbonation, widespread availability, and substantial quantities, hold great potential for carbon mitigation. Developing efficient and resilient carbon sequestration protocols utilizing iron and steel by-products is vital, as it addresses key challenges associated with mineral carbonation, such as high costs, slow reaction kinetics, and environmentally detrimental feedstock mining. In this review paper, various carbonation techniques for iron and steel by-products are evaluated and summarized. Different stages of essential carbonation processes are examined, along with their detailed physicochemical mechanisms. The review also explores recent technological advancements in this field, including the utilization of additives, supercritical carbonation, microwave irradiation, and ultrasonic enhancement, while assessing their potential to enhance process efficiency and sustainability. Additionally, the paper critically assesses representative processes from economic, environmental, and health perspectives. By providing an in-depth discussion of scalability, industrial implementations, economic feasibility, environmental toxicity, health impacts, and current technical barriers, this paper presents a comprehensive summary that addresses challenges, opportunities, prospects, and key insights in the field of mineral carbonation using iron and steel by-products. This effort represents a unique contribution to fill critical knowledge gaps in the mineral carbonation of iron and steel by-products, encompassing state-of-the-art technical advances and addressing their economic, environmental, and health implications. [Display omitted] • Mineral carbonation techniques for iron and steel by-products are reviewed. • Technological advances have enhanced process efficiency and economic feasibility. • Processes are assessed for economic, environmental, and health impacts. [ABSTRACT FROM AUTHOR]

Using geopolymer concrete (GC) is a technically feasible decarbonization strategy in the cement and concrete industry shown by numerous papers. A key factor determining its commercial application is whether its cost is competitive. However, related study is scarce. In this paper, we present the analysis of GC's CO 2 avoidance cost, the cost incurred to reduce one metric ton of CO 2 emissions. The results show that among the 486 GC mixtures analyzed, only seven yield negative CO 2 avoidance costs, while 379 are even more expensive than capturing CO 2 from cement plants, which is another technically feasible decarbonization strategy and has been evaluated to have a CO 2 avoidance cost of 55 USD/tCO 2 in Chinese demonstration project. Only a few GC mixtures with lower CO 2 avoidance costs will be considered by the industry, and they are associated with low activator dosage and high compressive strength. To quantify this relationship, we introduce the activator index (Ai), which refers to the activator dosage (kg·m−3) required to achieve 1 MPa of compressive strength. The result shows that Ai values below certain thresholds correspond to lower CO 2 avoidance costs and significant emission reductions of GC. This Ai -based criterion helps identify the optimal GC mixture that effectively reduces CO 2 emissions at the lowest possible cost, thereby promoting its commercial application. [Display omitted] • Only 7 of 486 geopolymer concrete (GC) mixtures have negative CO 2 avoidance costs. • CO 2 avoidance costs of most GC in literature exceed CO 2 capture. • The lower activator dosage per MPa strength, the lower CO 2 avoidance cost of GC. [ABSTRACT FROM AUTHOR]

• A new method for quantitatively monitoring CO 2 saturation in depleted gas reservoirs is proposed. • The ratio of the near detector's neutron capture gamma-ray count rate to the far detector's thermal neutron count rate measured by a four-detector pulsed neutron logging tool can effectively differentiate between CO 2 and CH 4. • The new method has higher CO 2 sensitivity compared to conventional count ratio methods. With favorable trap conditions and comprehensive infrastructure, depleted gas reservoirs create ideal spaces for the economic and efficient storage of carbon dioxide (CO 2). Accurate monitoring of CO 2 saturation is important for understanding CO 2 storage efficiency and distribution status. This paper proposes a new method for the quantitative monitoring of CO 2 saturation in CO 2 sequestration projects within depleted gas reservoirs. The new method uses the ratio of the near detector's neutron capture gamma-ray count rate to the far detector's thermal neutron count rate (RCN) measured by a four-detector pulsed neutron logging tool. In this paper, the RCN responses for different CO 2 saturation levels are studied using the Monte Carlo method, and the methods for roughly and accurately calculating CO 2 saturation are given. Moreover, the effects of formation factors such as lithology, clay mineral content, bound water salinity, and borehole environment on the RCN response are studied. Finally, the applicability of the RCN method is verified through a simulation example. The results show that the RCN method not only has high CO 2 sensitivity, but it also can accurately determine CO 2 saturation in depleted gas reservoirs and control the error of CO 2 saturation calculation within 2%. This study offers robust technical support for the evaluation of CO 2 saturation in depleted gas reservoirs. In addition, the proposed method has been proved applicable in the evaluation of CO 2 saturation in low-porosity reservoirs. [ABSTRACT FROM AUTHOR]

• CCUS development among EU countries with the latest progress in the field. • Realization of EGD targets with CCUS technology in EU. • Applicability of benchmarking method to compare environmental profiles. • UK and the Netherlands are among top countries with rapid CCUS development. • Poland and Germany with a high level of difficulty in achieving the EGD targets. Carbon Capture Utilization and Storage (CCUS) is a technology highlighted as one of the tools in climate change mitigation and one of the ways to reach the goal of 1.5℃ set by the Paris Agreement. The European Commission (EC) developed this goal by creating and implementing the European Green Deal (EGD) – the European Union's (EU) environmental policy. This paper provides an analysis of environmental policies and an overview of crucial CCUS projects of selected member states based on a benchmarking analysis of 27+ UK member states. An overall review of a total of 28 countries was undertaken based on economic and environmental factors. Afterward, a benchmarking analysis was performed ranking the countries according to the TOP10 for the selected five categories: total net emissions with international transport, percentage share of the energy sector, percentage share of fossil fuels, percentage share of fossil fuels in the Gross Electricity Production (GEP), and numbers of CCUS projects. Subsequently, a detailed and comprehensive overview of four selected member states was done, with a special focus on the national energy policy towards net-zero emission goals, the role of CCUS in domestic environmental policy, with current projects and facilities development. Finally, this paper outlines how the EGD has reformed the national energy policies of selected member states, and what is the part of CCUS technology in the national efforts towards climate neutrality. [ABSTRACT FROM AUTHOR]

Pathways to decarbonisation are commonly explored by government and industry through the use of energy system models. However, such models rarely consider where new energy infrastructure might be located. This is problematic as the spatial context of new renewable energy infrastructure will determine, in part, the environmental, social, and technical impacts of the energy transition. This paper presents the ADVENT-NEV model which brings together innovations in energy and natural capital modelling to identify the optimal locations of multiple renewable energy technologies at a national scale and high spatial resolution. Using Great Britain as a case study, the results show how the spatial distribution of renewable energy technologies changes when a natural capital approach is taken. In particular, the least-cost locations for onshore wind farms and bioenergy crops are highly influenced by the value of carbon sequestration, or emissions associated with their land use change. Siting using a natural capital approach produced appreciable ecosystem service benefits, such that the overall welfare gain to society was estimated at nearly £25 B. Overall, this paper demonstrates that understanding the geospatial context of the energy transition is essential to identifying which renewable energy pathways are consistent with decarbonisation and environmental objectives. [Display omitted] [ABSTRACT FROM AUTHOR]

Capturing CO 2 from air (DAC) is becoming an attractive technological route to face the climate crisis. This paper reviews the existing research efforts to integrate DAC with conversion technologies to transform the captured CO 2 into chemicals or fuels. The approach can potentially lead to net zero carbon emissions, thus being of interest in a circular economy framework. A growing amount of research has been devoted to the combination of DAC with CO 2 conversion, leading to creative strategies which start to be scaled up. In this review, we have critically analysed the existing approaches by the degree of process integration. From the point of view of process intensification, the integration of both capture and reaction in the same vessel can potentially lead to equipment and energy cost savings besides other synergistic effects. In this vessel, the DAC and conversion can occur either in consecutive stages with change of feed or spontaneously in a cascade reaction without changing the conditions. As a side effect, the benefits entailed by process intensification in different levels of integration may be a decisive driving force for the widespread deployment of DAC. This paper discusses the ongoing research and perspectives to guide researchers in this promising new field. • Direct air CO 2 capture is a promising measure to close the carbon cycle. • Different integration levels of DAC with conversion have been identified. • Higher integration levels can potentially reduce energy and equipment costs. • Obtaining a valuable product is an incentive to the deployment of DAC technology. [ABSTRACT FROM AUTHOR]

Drones, lasers and satellites measure forests with seemingly unprecedented detail. In Scotland, private companies are bringing these Advanced Measurement Technologies (AMTs) from ecological science to market. Companies offer landowners the chance to independently measure and verify natural capital commodities, such as woodland carbon credits, using these technologies. Drawing from 61 interviews with stakeholders in the Scottish land sector, alongside six months of ethnographic research, this paper explores the climate governance consequences of high-tech forest carbon measurement. The argument develops from the well-established premise within environmental STS that technologies' apparent objectivity and impartiality obscures the political-economic motivations shaping their use. In Scotland, AMTs are reflexively developed to generate increased financial value from forest creation schemes. AMTs find more carbon in forests than standard measurement practices allow. Carbon is 'known not grown': more numerous and legitimate carbon credits can be created through a shift in knowledge practices rather than a material shift in nature-based carbon sequestration. Three epistemic processes allow for more carbon to be 'known not grown'. Firstly, more carbon volume can be identified within a forest by using sophisticated measurement techniques. Secondly, conservative carbon estimates can be bypassed because of the perceived precision of AMTs. Thirdly, AMT developers cultivate a situated form of measurement accuracy by drawing upon a selective uptake of science. This paper argues 'known not grown' is a novel type of mitigation deterrence. It is a dangerous yet increasingly widespread phenomenon in neoliberal environmental governance and requires further empirical investigation. • Carbon measurement is developing along a privatised and technocratic trajectory. • Measurement technologies are taken from science to 'find' more carbon in forests. • Carbon is 'known not grown': more carbon is measured but not necessarily sequestered. • 'Known not grown' is a novel frontier of mitigation deterrence. • Finding natural capital is increasingly likely in neoliberal nature restoration. [ABSTRACT FROM AUTHOR]

Energy system autonomous control is influenced by day-ahead forecasting, despite being carried out independently in the literature. This paper develops an energy management modular platform that integrates multi-variable timeseries prediction and autonomous energy infrastructure scheduling in real-time. Firstly, an ensemble prediction model is developed for the day-ahead multi-energy and renewable power prediction, which is implemented by coupling variants of CNN, GRU, and BiLSTM models into a global model using an ensemble approach. Secondly, a deep reinforcement learning (DRL) with a soft actor critic (SAC) algorithm that include safety-guided network to make the policy network constraint-aware is proposed. A multi-energy system with renewable energy and carbon capture technology is then anticipated as the energy infrastructure for achieving a carbon neutral community and evaluating our proposed model. The proposed models are trained and tested on a real-world dataset from Arizona, USA. The ensemble prediction model achieved the least root mean squared error (RMSE). On the other hand, the improved DRL method exhibits superior performance in reducing energy cost, minimum constraint violation, and fast deployment compared to state-of-the-art DRL methods. Finally, the two models are coupled and carry out generalization performance on the prediction and energy management scheme, including the sensitivity analysis on carbon capture price, in the case studies. • A novel ensemble prediction model is proposed for multi-variable prediction. • A novel safe soft-actor DRL is proposed for real-time autonomous energy management. • The proposed method deals with physical constraint and security issue. • The coupling prediction and safe DRL control achieved optimal result. [ABSTRACT FROM AUTHOR]

This paper introduces the Possibilistic-Probabilistic Risk-based Smart Energy Hub (PPR-SEH) scheduling model, addressing cybersecurity challenges in the transition to advanced energy systems characterized by decarbonization, decentralization, and digitalization. The model integrates cutting-edge technologies like Carbon Capture Utilization and Storage (CCUS) and demand response programs. It addresses uncertainties from renewable energy sources, demand variability, fuel supply, and energy price fluctuations using a Z-number-based approach. Covering various energy types—electricity, heat, cooling, gas, and water—the PPR-SEH model offers a comprehensive energy management solution. Employing a mixed-integer linear programming (MILP) framework optimized with the CPLEX solver in GAMS software, it uses an epsilon constraint method and a fuzzy satisfying approach for solution selection. The model also evaluates the economic and environmental impacts of peer-to-peer energy-sharing markets linked with carbon emission trading, enhancing the efficiency and sustainability of energy distribution. The findings reveal that incorporating robust cybersecurity measures and integrating demand response and CCUS significantly influence operational efficiency and sustainability, evidenced by an increase in costs and pollution by approximately 11.43 % and 1.8 %, respectively, compared to deterministic approaches. This study underscores the importance of robust planning and the beneficial impact of a carbon system on load curve management and economic returns in smart energy systems. • Economic-Environmental Multi-Objective Model with demand Response Program. • Uncertainty Modeling with Possibilistic-Probabilistic Methods. • Cybersecurity Measures in Energy Systems. • Bi-Level P2P Energy Sharing Market Framework. • Simultaneous Implementation of Carbon Absorption System. [ABSTRACT FROM AUTHOR]

Organic Rankine cycle (ORC), biomass combustion and single-effect lithium bromide absorption refrigeration are appealing and promising technologies for combined heat, cool and power (CCHP) system. A novel biomass-fired CCHP system incorporating ORC and single-effect lithium bromide absorption refrigeration integrated with monoethanolamine (MEA)-based CO 2 capture is proposed in this paper, in which the pressurized hot water is used as heat source for ORC system and refrigeration cycle. Specifically, the condensation heat of ORC can be properly harvested for domestic hot water supplying. The refrigeration coefficient of r C is defined to characterize energy distribution relationship between ORC and refrigeration cycle. Results show the optimal evaporating temperature and heat source temperature are determined with refrigeration efficiency and net present value through gray correlation method when achieving excellent thermo-economic performance simultaneously. Besides, the optimal condensation temperature is directly affected by domestic hot water temperature. It further suggests that biomass-fired CCHP system incorporating ORC with cyclopentane owns the best thermo-economic performance with the maximum power efficiency of 7.4 %, refrigeration efficiency of 14 %, thermal efficiency of 81.5 % and primary energy saving ratio of 13.3 %. The optimized bioenergy system is thermodynamically and economically attractive, environment-friendly with negative CO 2 emissions substantially attributed to CO 2 capture. • A novel biomass-fired ORC-CCHP system integrated with SeBrLi absorption refrigeration and CO 2 capture is developed. • Optimal evaporation temperature and heat source temperature are determined with η C and NPV through gray correlation method. • Condensation temperature of the bioenergy system is optimized with a thermo-economic evaluation. • Thermo-economic comparison of different candidate working mediums concerning CO 2 capture is conducted. • Bioenergy system is thermodynamically and economically attractive with negative carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

• Multi-sensor fusing and soft computing in CO 2 leakage measurement. • Integration of BP-ANN, RF, and LS-SVM models. • Feature extraction and analysis of AE and temperature signals. • Effect of impurity gas on CO 2 leakage. CO 2 leakage from carbon capture and storage (CCS) networks may lead to ecological hazards, bodily injury and economic losses. In addition, captured CO 2 often contains impurities which affect the leakage behavior of CO 2. This paper presents a method for continuous and quantitative measurements of CO 2 leakage flowrate and the volume fraction of impurities by combining data-driven models with acoustic emission (AE) and temperature sensors. Three data-driven models based on artificial neural network (ANN), random forest (RF), and least squares support vector machine (LS-SVM) algorithms are established. The outputs from the three data-driven models are then integrated to give improved results. Experimental work was conducted on a purpose-built CO 2 leakage test rig under a range of conditions. N 2 was injected to the CO 2 gas stream as an impurity medium. Results show that the integrated model yields a relative error within ±4.0 % for leakage flowrate and ±3.4 % for volume fraction of N 2. [ABSTRACT FROM AUTHOR]