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• Carbon mineralization in mafic and ultramafic formations offers an attractive CO2 storage option. • Several key technical factors affecting the success, scale, and cost of in-situ carbon mineralization projects are discussed. • Overview of pilot tests, projects, and associated costs is provided. Carbon mineralisation in underground mafic and ultramafic formations, known as in-situ carbon mineralisation, has emerged as an attractive technology for permanent CO 2 storage. Despite its potential, this method has received limited attention compared to conventional CO 2 storage in sedimentary formations. However, increasing interest from countries and companies in utilising this approach to permanently store CO 2 via carbon mineralisation has grown in recent years as part of the wider carbon capture and storage expansion seen globally. This review paper aims to provide an in-depth overview of in-situ carbon mineralisation technology. The paper covers key factors crucial for successful implementation, including water consumption, CO 2 injection rate, risk of CO 2 leakage, injectivity, fracture characterisation, pressure management and induced seismicity, thermal effects, surface area of minerals, groundwater contamination, injection strategy, monitoring of confinement, and reservoir modelling. The paper also discusses pilot tests and projects, highlighting their outcomes. Furthermore, it discusses the costs associated with in-situ carbon mineralisation and provides a case study. The primary objective of this paper is to increase awareness and understanding of this relatively new technology within the carbon capture and storage industry. By shedding light on the benefits and challenges of carbon mineralisation in mafic and ultramafic formations, this review aims to encourage further research, development, and adoption of this promising approach for CO 2 emissions reduction and permanent CO 2 storage. [ABSTRACT FROM AUTHOR]

In the context of carbon emission reduction in the shipping industry, CCUS technology can modify ships to reduce carbon emissions, providing a new direction for the green development of the shipping industry. Based on this, this paper investigates the technology related to carbon capture on ships, firstly puts forward the applicable requirements of carbon capture technology; and analyses the adaptability of the existing carbon capture solutions to the shipping industry; and discusses the development prospect of carbon capture on ships through the three challenges of space utilisation, safety, and economy; and finally analyses the related policies. After analysis and discussion, this paper concludes that the alcohol-amine method is the most suitable carbon capture solution for ships, but there are challenges in economics and space utilisation. The future research direction lies in optimising the performance of the absorber, improving the energy efficiency of the system and solving the CO 2 storage problem. • It analyzes the current situation of the development of the carbon emission reduction business in the shipping industry, and introduces the application of carbon capture, utilization and storage technology (CCUS) in the shipping industry; • The applicable requirements for carbon capture on ships are proposed with regard to the ship's own characteristics; • Carbon capture process types are described in detail and the feasibility of different processes applied to the shipping industry is analyzed; • Summarises the existing cases of carbon capture on board ships and describes the challenges faced by carbon capture technology on board ships. [ABSTRACT FROM AUTHOR]

According to the construction of the cascade hydropower stations in the lower reaches of the Yalong River and the ecological environment condition of the river, a medium and long-term optimal dispatching model with the goal of maximizing the power generation benefits of the cascade hydropower stations is established, and the dynamic programming method is used to optimize the solution, so as to obtain the ten-day average maximum power generation of cascade hydropower stations. According to the latest relevant research at home and abroad, it is found that during the power generation process of the hydropower station, the discharge will produce certain greenhouse gas (GHG) emissions during the delivery process. In this paper, the greenhouse gas emissions existing in the power generation process of cascade reservoirs are considered, and the typical values are selected to calculate the average greenhouse gas (mainly CO 2) emissions from 2001 to 2018, twelve plants with strong carbon sequestration and oxygen release capacity and suitable for growing in the basin are selected, and the mitigation and improvement measures of greenhouse gas emissions around the reservoirs in the basin are given. A new research idea is provided for the Yalong River cascade reservoirs to focus on the power generation benefits while reducing the greenhouse gas emission situation to a certain extent. [ABSTRACT FROM AUTHOR]

Interest in low emissions hydrogen as an energy vector to assist in deep decarbonization goals has gained momentum recently. In this paper, we explore local hydrogen production from natural gas with CO 2 capture and sequestration (known as "blue" H 2) to support Singapore's intended inclusion of low-carbon intensity H 2 fuel as a way to achieve significant CO 2 emission reduction through 2050. A superstructure-based model is used to minimize the total cost or emissions of the entire supply chain, from H 2 production to consumption in the power, industry, domestic, marine, and road transport sectors. H 2 demand for each sector is projected for three H 2 penetration scenarios (low, medium, and high). The results are analyzed for the levelized cost of H 2 , reduction in carbon emissions, and cost of carbon avoidance. Costs associated with direct and indirect CO 2 emissions, as well as H 2 and CO 2 infrastructure costs, are included in total costs. A comparison of blue H 2 and direct natural gas utilization with post-combustion CO 2 capture and sequestration is also presented. We find that decarbonizing Singapore via local production of blue H 2 will involve a relatively high carbon avoidance cost. • A Multi-Period hydrogen supply chain optimization model is developed. • Decarbonizing Singapore via local production of blue H 2 is investigated. • The local production capacity could reach as high as 32,000 TPD to meet all H2 demand. • For marine transport, LNH3 is less expensive than LH2. • H2 fuel cell electric vehicles should be considered for heavy-duty vehicles. [ABSTRACT FROM AUTHOR]

This paper investigates the viability of CO 2 storage in geological formations, including depleted hydrocarbon reservoirs applying 3-dimensional seismic and well data of the Niger Delta region as a case study for CO 2 sequestration, which represents an essential initiative for the reduction of greenhouse gas emissions. Different theoretical and experimental studies from literature on CO 2 sequestration in geological formations across the world, including the Niger Delta, are reviewed. The Niger Delta basin has a high potential for CO 2 sequestration, and this indication is shown through the review of research papers undertaken outside and within the basin, which reveal the presence of massive hydrocarbon fields, lateral continuity of reservoir, reservoir-seal pairs, faults, and traps, developed hydrocarbon fields, appropriate reservoir depth. The gaps identified from the review of various research studies are analyzed to form the basis of a future research investigation for capturing, removing, and storing CO 2 in depleted hydrocarbon reservoirs and other geological formations. The authors deduced that accurate injection pressure, rate, and depth estimation are critical factors for CO 2 sequestration and need to be thoroughly investigated. • Niger Delta depleted oil/gas reservoir CO 2 capture, utilization & storage reviewed • Potential issues relating to CO 2 sequestration and modeling in Niger Delta noted • Appropriate CFD solution should combine static and dynamic model. • Research gaps identified and future directions recommended. [ABSTRACT FROM AUTHOR]

Reducing greenhouse gas emissions in the shipping sector is a challenging task. While renewable fuels stand out as the most promising long-term solution, their near- and mid-term viability is hampered by limited availability and high costs. An alternative approach is onboard carbon capture, which can reduce emissions from new ships as well as retrofitted vessels. This paper examines the techno-economic potential of oxyfuel combustion based carbon capture on ships. The oxyfuel concept uses an oxygen-rich atmosphere in the combustion process, resulting in a mixture of carbon dioxide and water. After the condensation of water, the carbon dioxide rich gas can be directly stored on board. Various onboard oxygen supply concepts are investigated, including different technologies for onboard air separation and liquid oxygen bunkering. Influences on the ship energy system are studied by system simulation of a deep-sea container vessel. Benchmarked against a technologically mature post-combustion carbon capture system, the results show that the oxyfuel concepts have limited competitiveness because of reduced engine efficiencies and high energy demands for onboard oxygen supply. Avoiding onboard oxygen supply by using liquefied oxygen as a byproduct from onshore electrolysis increases energy efficiency and the competitiveness of oxyfuel combustion but requires additional storage space. Sensitivity analyses highlight that the engine combustion concept and engine efficiency are the most critical influences on the techno-economic performance. • Oxyfuel combustion faces significant challenges compared to post combustion concepts • High fuel penalty mainly caused by the drop in efficiency of the combustion engine • The use of onboard liquid oxygen storage tanks offers techno-economic advantages • High potential for significantly reduce total CO 2 emissions with oxyfuel combustion [ABSTRACT FROM AUTHOR]

[Display omitted] • Recent advances in state-of-the-art membranes for H 2 /CO 2 separation were reviewed. • The performance and advantages of these H 2 /CO 2 separation membranes were provided. • Key aspects of membrane design and simple economic evaluation were summarized. • Future research directions based on the development bottlenecks were proposed. H 2 /CO 2 separation is an essential step to produce clean energy and reduce greenhouse gas emissions, contributing to sustainable development and addressing climate change challenges. As a promising strategy for carbon capture and hydrogen purification, membrane separation technology has attracted lots of attention due to its simple operation process, efficient and energy-saving characteristics. This paper reviews recent advances in inorganic membranes, organic membranes, mixed matrix membranes (MMMs), and heterostructured membranes for H 2 /CO 2 separation, introduces their characteristics and advantages, and clarifies the optimal using conditions. Key aspects of membrane design such as multiphase design, microstructure control, separation mechanisms, and simple economic evaluation are also summarized. Finally, the main challenges and future research prospects of H 2 /CO 2 separation membrane are proposed, aiming to provide enlightening insights for the development of H 2 /CO 2 separation membranes. [ABSTRACT FROM AUTHOR]

As major strategic development areas in China, the provinces around the Yangtze River are facing the pressure of large aggregate CO 2 emissions and high per capita CO 2 emissions. The study on the pathway of reducing CO 2 emissions and increasing carbon sequestration will help China better clarify the ways realize the goals of carbon peak and carbon neutrality as soon as possible. In this paper, the extended STIRPAT model and OLS regression were used to establish a prediction model to estimate the CO 2 emissions during 2010–2060 under different scenarios. Meanwhile, the InVEST model was used to estimate the carbon sequestration, and the comparison with the CO 2 emissions was analyzed. The results show that Qinghai and Yunnan have achieved the goal of carbon neutrality in 2010. Under the low-carbon and energy-saving scenario and the baseline scenario, all provinces within the study area are anticipated to attain their emissions peak by 2030 or earlier, and the CO 2 emissions peak value of the whole study area is 3111 Mt and 3199 Mt, respectively. While under the high emissions scenario, only Chongqing and Qinghai will reach the emissions peak in 2030, and the whole study area will reach the emissions peak in 2040, with peak value of 3470 Mt. Under the three scenarios, the whole study area cannot achieve carbon neutrality before 2060. Only Sichuan and Hubei can achieve carbon neutrality in 2050 and 2060 under the low-carbon and energy-saving scenario. All provinces and municipalities in the lower reaches of the Yangtze River are facing huge pressure of emissions reduction. The research reveals that the goals of carbon peak and carbon neutrality should be achieved by developing clean energy, transforming industrial structure, increasing carbon sequestration and improving carbon emissions trading system. [Display omitted] • The CO 2 emissions showed a pattern of increase during 2010–2020. • The whole study area will achieve carbon peak by 2040 or earlier. • The whole study area cannot achieve carbon neutrality before 2060. • The realization pathway of carbon peak and neutrality was proposed. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions have led to severe global climate change, and countries around the world are taking measures to mitigate the greenhouse effect caused by carbon emissions. Carbon dioxide capture, utilization and storage (CCUS) is emerging as a large-scale greenhouse gas emission reduction technology and can potentially become an important means to mitigate the greenhouse effect in the future. There are a series of problems in the implementation of this technology, among which the geomechanical problems due to the thermal effect should not be neglected. This paper summarizes the non-isothermal processes in CCUS and the impacts and hazards caused by the thermal effects of non-isothermal processes. We show that CO 2 injection and sequestration will experience heat exchange with high-temperature formations and wellbores, exothermic dissolution, cooling by the Joule–Thomson effect, exothermic adsorption and exothermic hydrate formation when CO 2 replaces CH 4. These non-isothermal processes can lead to risks including reservoir stability, fault activation and induced seismicity. Thermal effects can also alter reservoir characteristics, such as the effect on CO 2 injection and storage efficiency. This work presents the challenges and future perspectives of thermodynamic studies in CCUS, which will help to fully understand the thermal effects and risks in CCUS and provide a reference for future CCUS operation, monitoring, and research. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) is a promising technology for reducing greenhouse gas emissions, however, leakage of CO 2 constitutes a major concern for aquifers. Despite abundant literature on petrophysical and geochemical changes at storage conditions, few studies address the impact of CO 2 leakage on petrophysical and at aquifer-like pressures, flow rates and temperatures. The aim of the paper is to study and quantify at the core scale, the effects of various factors, including flow rates, fluid salinities, CO 2 concentrations and limestone carbonate facies, on the petrophysical and geochemical parameters of a carbonate freshwater aquifer during an experimental CO 2 leakage. To achieve this, successive CO 2 -rich water percolation experiments were performed at the core scale, while monitoring changes in petrophysical parameters and water chemistry. During our experiments, initial permeability increments were observed for both rock samples, followed by decreases in later experiments. Evidence of pore clogging and wormholes was also observed. It was found that the transport of particles led to significant porosity creation. The water monitoring sensors were sensible to the experimental leakage conditions, particularly electrical conductivity. The results of this study contribute to the understanding of petrophysical changes in carbonate aquifer systems by anticipating which type of aquifers are more vulnerable to dissolution and to what extent the CO 2 leakage conditions modify the petrophysical parameters. • Water-rich CO 2 percolation experiments on limestones at different conditions. • Transport of fine particles led to pore clogging and porosity increase. • Increasing the CO 2 concentrations, salinities and flow rates encouraged dissolution. • Significant difference in porosity increase depending on sedimentary facies. [ABSTRACT FROM AUTHOR]

System modelling efforts have shown that carbon capture is a key technology to enable a cost-effective reduction of hard-to-abate emissions in energy-intensive industries. The CO 2 that is captured can either be utilised (CCU), or stored with carbon capture and storage (CCS). This paper examines the implications of both European carbon pricing mechanisms (ETS I & ETS II) on the level-playing field between CCS and CCU investments. Our contribution is threefold. First, we develop an equilibrium model that enables us to mimic market outcomes under different regulatory conditions. With a numerical case study applied to a fuel production chain, the model confirms that the current ETS regulation can have an adverse effect on CCU uptake. Especially with zero or low ETS II prices a lock-in effect can occur on CCS, potentially prolonging conventional refinery activities. Second, we propose an alternative approach to better integrate CCUS into the EU ETS. Results show that this approach maintains the level-playing field between CCU and CCS, regardless of any carbon price differentials. That results in a closer to Pareto optimal outcome in terms of welfare and emission abatement. Third, we present an analytic analysis to express the CCUS trade-off from a theoretical point of view. This provides generalised and concrete insights into how EU ETS influences the profitability and likelihood of CCUS. Our results help policymakers to gain a better understanding of the impact of ETS regulations on decarbonisation efforts in the industry. [ABSTRACT FROM AUTHOR]

Abstract Global warming due to the emission of greenhouse gases, especially carbon dioxide (CO 2), has a significant effect on the climate change and has become a widespread concern in the recent years. Carbon capture, utilization, and sequestration (CCUS) strategy appears to be effective in decreasing the carbon dioxide level in the atmosphere. Despite a great progress in this field, there are still major limitations in commercialized the CO 2 capture methods that rely on absorption phenomena. High capital costs of for the CO 2 capture, low absorption and desorption rates (which require large facilities), solvent losses due to evaporation, and the use of corrosive solvents are among main obstructions. Recently, CO 2 capture with ionic liquids (ILs) has appreciably attracted researchers’ attention. The distinct properties of ILs such as negligible vapor pressure and their affinity to capture the CO 2 molecules make them a feasible alternative for currently available solvents including, different amines. This paper covers a brief review of previous engineering and research works on various CO 2 capture techniques, the description of CO 2 capture process using ILs, mechanisms of the CO 2 capture with ILs at molecular level, CO 2 and ILs properties, characterization of the CO 2 /IL systems, impacts of operating and fluids conditions on CO 2 absorption capacity by ILs, and CO 2 solubility and selectivity in ILs. Moreover, the technical and economic aspects of the CO 2 capture with ILs, screening criteria for ILs/CO 2 systems, and important results obtained from previous studies will form the last parts of this manuscript. This review offers a proper/systematic guideline that assists researchers and engineers to comprehensively understand and to effectively design the CO 2 /ILs processes, focusing on the thermodynamic and mass transfer aspects. Highlights • CO 2 capture with ionic liquids (ILs) appears to be a promising strategy in the future. • This review paper describes carbon capture process using ILs, mechanisms, and challenges. • This paper discusses about different characterization tools for ILs/CO 2 systems. • CO 2 capture efficiency is studied at various conditions through parametric sensitivity analysis. • Technical and economic aspects and screening criteria for ILs/CO 2 systems are highlighted. [ABSTRACT FROM AUTHOR]

• Proposed BECCS deployment criteria are based on socio-enviro-economic objectives. • Life cycle emissions and carbon abatement costs are calculated. • Some of the BECCS pathways are less likely to achieve net negative emissions. • Balancing between socioeconomic aspects such as local job creation opportunities, cost, feedstock supply chain disruptions, and emission reduction targets is discussed. Countries are considering different options to achieve net zero emissions including Bioenergy with carbon capture and storage (BECCS), which is the process of capturing and storing CO 2 from processes that use bioenergy to produce heat, electricity, or biofuels. However, this technology faces sustainability concerns and possesses complex value chains of its emissions. Adding further to this complexity, the literature indicates two opposing views with respect to the potential of BECCS in terms of being able (or unable) to achieve negative emissions. Hence, this paper analyzes in detail a wide range of BECCS pathways in terms of their ability to achieve negative emissions along with their associated costs. Out of seven assessed pathways, our analysis shows that corn to ethanol and biomethane production from maize BECCS pathway in the USA, biomethane production from wet manure in Europe, and baling of straw pellets with trans-Atlantic shipment can achieve negative emissions at a cost of 50, 108, 159, and 232 dollars per ton of CO 2 ($/tCO 2) respectively. Other technologies like poplar pellets, forest residue, and agricultural residue with trans-Atlantic shipment are not able to achieve negative emissions. [ABSTRACT FROM AUTHOR]

The adoption of soil organic carbon sequestration (SCS) practices on agricultural land offers the double advantage of offsetting greenhouse gas (GHG) emissions and improving soil quality. However, little is known about the drivers that might influence winegrowers to adopt these practices, whose uptake remains low on viticultural land. Better understanding these drivers will be crucial to evaluate the efficacy of current policies in the viticulture sector in promoting and incentivising soil organic carbon sequestration in vineyards. This paper identified the factors influencing the adoption of SCS practices by winegrowers in France. A survey of 400 winegrowers investigated current rates of adoption and winegrowers' perceptions of the practices. A binary logistic model suggested that winegrower's age, being an independent winegrower, farm size, the number of workers hired, vine's age, being certified High Environmental Value (HVE), being certified organic, practising irrigation, receiving subsidies, and winegrower's perceived resources, attitude towards SCS practices and confidence significantly influenced the decision to adopt the practices, though their influence differed depending on the practice. The findings provide insights for GHG mitigation planning targeting the viticulture sector • We examined the factors influencing the adoption of viticultural practices in France. • We focused on practices enhancing soil organic carbon sequestration. • A survey of 400 winegrowers investigated uptake and perceptions of the practices. • Organic certification, resources and winegrowers' confidence significantly influenced practice adoption. • Results provide insights for policy making in the viticulture sector. [ABSTRACT FROM AUTHOR]

The major contributor to global warming is human-generated greenhouse gases (GHGs) emissions that pollute the air. GHGs emissions are a global issue dominated by emission of carbon dioxide (CO 2 ). Notably, CO 2 accounts for an estimated 77% of GHGs and thus has a huge impact on the environment. The capture, sequestration, and utilization of CO 2 emissions from flue gas are now becoming familiar worldwide. These methods are a promising solution to promote sustainability for the benefit of future generations. Previously, many researchers have focused on capturing and storing CO 2 ; however, less effort has been spent on finding ways to utilize flue gas emissions. Moreover, several issues must be overcome in the field of carbon capture and sequestration (CCS) technology, especially regarding the cost, capacity of storage and the durability of the storage reservoir. In addition, this paper addresses new technology in carbon capture and sequestration. To make CCS technology more feasible, this paper suggests a sustainable method combining CCS and biofuel production using CO 2 as a feedstock. This method offers many advantages, such as CO 2 emission mitigation and energy security through the production of renewable energy. Due to the many advantages of biofuels, the conversion of CO 2 into biofuel is a best practice and may provide a solution to pollution while encouraging sustainability practises. [ABSTRACT FROM AUTHOR]

• Investigations on different types of nanofluids and their performance. • Understanding the effects of nanoparticle types on the behaviour of nanofluid. • Analysis of CO 2 capture using nanofluids. Development of novel, efficient and cost-effective strategies to diminish the permanent emission of greenhouse gases (GHGs) to the atmosphere has been an indisputable concern for scientists. CO 2 is known as the most prominent GHG, which its abnormal amount in the atmosphere accelerates the occurrence of unfavorable environmental events such as acid rain, ocean acidification, global warming, and soil degradation. Nowadays, application of various nanofluids for increasing separation efficiency of CO 2 has been an attractive subject due to their certain privileges such as chemical compatibility and great specific area. This paper tries to provide an up-to-date overview of the commonly-employed nanofluids accompanying with their properties and applications to enhance the separation efficiency of CO 2. Moreover, important mechanisms toward improving the mass transfer rate and the separation proficiency of CO 2 through the nanofluids are comprehensively discussed and summarized. Single material nanofluids (SMNFs) and hybrid nanofluids (HNFs) are considered as major categorizations of commonly-employed nanofluids in the scientific scope of membrane-based gas separation process (MGSP), which are aimed to be discussed in this paper. True recognition of nanofluids application in the CO 2 separation process leads to finding its advantages/disadvantages in comparison with other conventional procedures. [ABSTRACT FROM AUTHOR]

• Advanced clean coal technologies and CCS could provide promising solutions for reducing CO 2 emissions up to 45% in comparison to BAU by 2050. • Coal demand changes to 1100-1400 Mt in 2030 and 1132-2200 Mt in 2050 under alternate future scenarios • CO 2 emissions from coal changes to 45-69% in 2030 and 34-67% of the total emissions in 2050 under alternate future scenarios. • Mitigation measures first decarbonize the power sector due to availability of flexible choices. Simultaneously it decarbonizes the other economic sectors. • Analysis shows that energy security and deep GHG emission mitigation is possible. Rapid shift from traditional energy intensive pathways is required to pace-up economic growth before exhausting remaining carbon budget under 2 °C global stabilization target. Within this larger context, in this paper we have used AIM/End-use, a bottom-up, techno-economic model to analyze India's energy security and greenhouse gas (GHG) emissions from the year 2000 to 2050 with a focus on possibilities of coal continuance in India. Our analysis shows that by adopting advanced coal technologies and carbon dioxide capture and sequestration (CCS) options, up to 45% CO 2 emission reduction can be achieved over business-as-usual scenario (BAU) by 2050. This is possible even when coal use would increase to nearly 2200 Mt in 2050 as against 870 Mt in 2017-18. Without CCS, coal use could peak at 1200 Mt with 22% CO 2 reduction over BAU in 2050 but in that case nuclear and renewable energy would become pivotal in meeting energy demand. The paper concludes that a win-win integration of energy security and deep GHG emission mitigation is possible through a large-scale integration of advanced coal technologies and CCS in Indian energy systems. We have also provided a brief PESTLE analysis for finding the enabling environment necessary for achieving the results discussed in various scenarios. [ABSTRACT FROM AUTHOR]

This paper critically reviewed the current knowledge and challenges of rice husk biochar (RHB) production and its effects on soil properties, plant growth, immobilization of heavy metals, reduction of nutrient leaching and mitigation of greenhouse gas emissions. The characteristics of RHBs produced at various pyrolysis temperatures were discussed and compared to biochars derived from other agro- industrial wastes. RHBs produced at higher pyrolysis temperatures show lower hydrogen/carbon ratio, which suggests the presence of higher aromatic carbon compounds. The increase of pyrolysis temperature also results in production of RHBs with higher ash content, lower yield and higher surface area. RHB usually has higher silicon and ash contents and lower carbon content compared to biochars derived from other feedstocks at the same pyrolysis conditions. Although it depends on soil type, RHB application can improve soil organic carbon content, cation exchange capacity, available K concentration, bulk density and microbial activity. The effect of RHB on soil aggregation mainly depends on soil texture. The growth of different crops is also enhanced by application of RHB. RHB addition to soil can immobilize heavy metals and herbicides and reduce their bioavailability. RHB application shows a significant capacity in reduction of nitrate leaching, although its magnitude depends on the biochar application rate and soil biogeochemical characteristics. Use of RHB, especially in paddy fields, shows a promising mitigation effect on greenhouse gas (CH 4 , CO 2 and N 2 O) emissions. Although RHB characteristics are also related to other factors such as pyrolysis heating rate and residence time, its performance for specific applications (e.g. carbon sequestration, pH amendment) can be manipulated by adjusting the pyrolysis temperature. More research is needed on long-term field applications of RHB to fully understand the advantages and disadvantages of RHB as a soil amendment. [ABSTRACT FROM AUTHOR]

Recently, the decarbonization of the power industry has gained increasing attention as global warming problem has become more acute. However, the existing system planning models targeting to tackle emission reduction rarely consider to improve the flexibility of power system. In this paper, a co-planning model considering the expansion of carbon capture and storage (CCS) units and energy storage systems (ESSs) is proposed, in which the carbon emission target is embedded in the objective function via setting different carbon emission tax. Here, the system flexibility is improved by Source-Load-Storage (SLS) response, which is achieved via CCS units, ESSs and flexible load. In addition, a subsidy method for cost recovery based on Vickrey-Clark-Groves (VCG) mechanism is proposed to stimulate market members participating in SLS response. Numerical results from a modified IEEE 118-bus power system illustrate the impact on system cost and emission results owing to specific carbon emission tax, investment budget and SLS response. Finally, we display the contribution rate and subsidy of different participants in a typical day. • We propose an expansion co-planning model of ESSs and CCS units. • Source-load-storage response is considered at operation stage. • A methodology based on VCG mechanism is designed for cost recovery. • Our model provides a transition solution towards low-carbon power systems. [ABSTRACT FROM AUTHOR]

The transition to a deeply decarbonized energy system requires coordinated planning of infrastructure investments and operations serving multiple end-uses while considering technology and policy-enabled interactions across sectors. Electricity and natural gas (NG), which are vital vectors of today's energy system, are likely to be coupled in different ways in the future, resulting from increasing electrification, adoption of variable renewable energy (VRE) generation in the power sector and policy factors such as cross-sectoral emissions trading. This paper develops a least-cost investment and operations model for joint planning of electricity and NG infrastructures that considers a wide range of available and emerging technology options across the two vectors, including carbon capture and storage (CCS) equipped power generation, low-carbon drop-in fuels (LCDF) as well as long-duration energy storage (LDES). The model incorporates the main operational constraints of both systems and allows each system to operate under different temporal resolutions consistent with their typical scheduling timescales. We apply our modeling framework to evaluate power-NG system outcomes for the U.S. New England region under different technology, decarbonization goals, and demand scenarios. Under a global emissions constraint, ranging between 80%–95% emissions reduction compared to 1990 levels, the least-cost solution relies significantly on using the available emissions budget to serve non-power NG demand, with power sector using only 14%–23% of the emissions budget. Increasing electrification of heating in the buildings sector results in greater reliance on wind and NG-fired plants with CCS and results in similar or slightly lower total system costs as compared to the business-as-usual demand scenario with lower electrification of end-uses. Interestingly, although electrification reduces non-power NG demand, it leads to up to 24% increase in overall NG consumption (both power and non-power) compared to the business-as-usual scenarios, resulting from the increased role for CCS in the power sector. The availability of low-cost LDES systems reduces the extent of coupling of electricity and NG systems by significantly reducing fuel (both NG and LCDF) consumption in the power system compared to scenarios without LDES, while also reducing total systems costs by up to 4.6% for the evaluated set of scenarios. • A decarbonized joint electric power and natural gas model is developed. • Impact of electrification, coupling constraints, and new technologies are analyzed. • Joint planning with cross-sectoral emission limit is the most cost-effective pathway. • Increased use of carbon capture technologies can increase overall NG consumption. [ABSTRACT FROM AUTHOR]

The climate impact of the iron and steel industry can be mitigated through increased energy efficiency, emission efficiency, material efficiency, and product use efficiency resulting in reduced product demand. For achieving ambitious greenhouse gas (GHG) mitigation targets in this sector all measures could become necessary. The current paper focuses on one of those four key measures: emission efficiency via innovative primary steelmaking technologies. After analysing their techno-economical potential until 2100 in part A of this publication, the current research broadens the evaluation scope for the crucial year 2050, based on a Multicriteria-Analysis (MCA). 12 criteria from five different categories (“technology”, “society and politics”, “economy”, “safety and vulnerability” and “ecology”) are used to assess the same four future steelmaking technologies in a systematic and holistic way in Germany, as one possible location. The technologies in focus are the blast furnace route (BF–BOF), blast furnace with carbon capture and storage (BF–CCS), hydrogen direct reduction (H–DR), and iron ore electrolysis (EW). These four technologies have been selected, as explained in part A of this paper, because they are the most commonly discussed technological options under discussion by policymakers and the iron and steel industry. The results of the current work should provide decision makers in industry and government with a long-term guidance on technological choices. In 2050 the MCA shows significantly higher preference scores for the two innovative routes H–DR and EW compared to the blast furnace based routes. The main reasons being higher scores in the economical and environmental criteria. BF–CCS shows its greatest weakness in the social acceptance and the safety and vulnerability criteria. BF–BOF has the lowest economy and ecology score of all assessed routes, which is due to the projected high cost for carbon dioxide emission and increasing prices for fossil fuels. A first indicative trend assessment from today towards 2050 shows that H–DR is the preferred MCA option from today on. Three exemplary weighting distributions (representing the perspectives of the steel industry, environmental organisations and the government), used to simulate different stakeholder angle of view, don't have a strong influence on the overall evaluation of the steelmaking routes. The results remain very similar, with the highest scores for the innovative routes (H–DR and EW). This leads to the conclusion that EW and in particular H–DR can be identified as the preferred future steelmaking technology across different perspectives. Specific innovation efforts and dedicated programs are necessary to minimize the time until marketability and to share the development burden. The similarity of the MCA results from different perspectives indicates a great opportunity to reach a political consensus and to work together towards a common future goal. Regarding the pressing time horizon a concentrated engagement for one (or few) technological choices would be highly recommended. [ABSTRACT FROM AUTHOR]

• Compared the impact of solvent (e.g. amine) versus Cryocap™ H2 cryogenic technology on CO2 emission reductions rates for hydrogen production with SMR. • Assessed direct and indirect emissions for solvent (e.g. amine) and Cryocap™ H2 technologies for various electrical carbon footprint scenarios. • Total CO2 emissions are reduced with Cryocap™ H2 compared to solvent technologies. • CO2 emissions reduction rates for Cryocap™ H2 are higher than solvent technologies across all power grid footprint scenarios. As hydrogen is increasingly being recognized as a critical energy vector in the energy transition, capturing CO 2 from existing H 2 production facilities plays a significant role towards decarbonisation. Air Liquide has industrialized an innovative technology Cryocap™ H2, combining membranes and cryogenic solutions to capture CO 2 most efficiently, at the lowest cost, and at a very high purity. This paper illustrates the impact of cost-effective partial capture technology choices (e.g. amine wash versus Cryocap™ H 2) to CO 2 emission reduction rates and overall carbon footprint. Direct and indirect emissions (i.e. Scopes 1, 2, and 3) were defined for each technology choice, alongside scenarios for low, medium, and high carbon footprint environments. The paper also explores an optimization path on the CO 2 emissions reduction rate using a network configuration within a refinery. The study demonstrates that with Scope 1 emissions, the partial capture net CO 2 emission reduction rate is 62% with a Cryocap™ standalone, 80% with a Cryocap™ Network, but only 56% with an amine wash due to its additional requirement of steam. Analysis of all emissions Scopes illustrates that Cryocap™ 's net CO 2 emissions reduction rate ranges from 52% to 66% across low, medium, to high carbon footprint scenarios, and 39% to 44% for amine wash. The advantageous case for Cryocap™ across all three Scopes remains regardless of the additional steam production method (i.e. natural gas vs electric boiler). [ABSTRACT FROM AUTHOR]

This paper examines the life-cycle greenhouse gas (GHG) emissions reduction and associated marginal costs (MC) in Japan when the government enhances the transition to battery electric passenger vehicles (BEVs) by implementing a rapid investment regime for charging stations and fossil-fueled vehicle bans. Important factors affecting BEV emissions are battery performance, battery production technology, electricity generation mix and battery minimum state of charge (SOC min). We find that in addition to a rapid investment regime, a fossil-fueled vehicles ban policy is necessary to significantly increase the uptake of BEVs and achieves the deepest reduction in life cycle GHG emissions. Under this policy, with carbon neutral electricity by 2050 and a low SOC min charging regime, life-cycle GHG emissions are reduced by 48% and the MC by 53% in 2060. A carbon neutral light transport fleet in 2050 will require carbon capture and storage to offset 24 million tonnes-CO 2 equivalent of emissions even if electricity is carbon neutral by 2050 and users adhere to a low SOC min charging regime. [Display omitted] • Enhanced infrastructure development has a little impact on the uptake of BEVs. • The more stringent vehicle ban reduces life cycle GHG emissions the most. • Battery charging regime is crucial to GHG emissions reduction and associated cost. • Improving battery and vehicle production is crucial to GHG emissions reduction. • Carbon neutral light vehicle transport by 2050 requires carbon capture and storage. [ABSTRACT FROM AUTHOR]

• The tendency of mineral dissolution in hydrocarbon reservoir during CO 2 injection varies in different rock types. • A higher temperature condition is expected to increase the rate of CO 2 -brine-rock chemical reaction. • Carbonate rocks have a higher tendency to chemically react and more susceptible to rock properties alteration. • Permeability and porosity of rock would considerably increase when large pores become opened due to mineral dissolution. • A more elaborate study of the possibility of injecting CO 2 in volcanic rocks is proposed. Enhanced oil recovery (EOR) by carbon dioxide (CO 2) injection is a critical technique in the decarbonization process of the world. This method involves injecting CO 2 into existing hydrocarbon reservoirs to increase oil recovery. CO 2 -EOR has been used as a tertiary oil recovery technique for many years, and it has proven to be effective in enhancing oil recovery while reducing greenhouse gas emissions since the reservoir could serve as permanent storage site for CO 2 sequestration. The composition of CO 2 allows it to dissolve in crude oil, reducing its viscosity and promoting hydrocarbon flow. However, when CO 2 is injected into the reservoirs, it can react with the rock minerals and water, leading to the alteration of petrophysical properties of the hydrocarbon reservoirs. The precipitation of certain minerals can lead to pore blockage in the reservoir formation, which could reduce the performance of the CO 2 -EOR injection process and the integrity of the reservoir for storage. The complex nature of the tight pore throat of hydrocarbon reservoirs indicates that the pore structure could vary significantly in size from the microscale to the nanoscale, affecting the properties of the reservoir and oil-displacement efficiency. The magnitude of the rock property alteration during CO 2 injection has been reported to vary depending on the rock type and injection strategies adopted. Thus, to evaluate the effects of CO 2 injection in rocks, laboratory experiments are being used to analyse the processes using core samples, while numerical simulation approaches have also been employed to model the processes of fluid migration from the reservoir to the caprock layer. The dynamics of fault opening and mechanical failure in rocks have also been addressed using coupled thermo-hydro-mechanical-chemical (THMC) processes modelled on different scales. Overall, CO 2 -EOR and carbon sequestration is an important technique for enhancing oil recovery and reducing greenhouse gas emissions. However, it is essential to prioritize the effects of the CO 2 injection on different rock types, pore type, and technology used to achieve efficient results as reviewed in this paper. [ABSTRACT FROM AUTHOR]

[Display omitted] • The displacement and miscible behaviors of CO 2 and octane in calcite nanoslits are investigated by molecular dynamics simulations. • Increase of the temperature and slit aperture could promote the miscible progress of CO 2 and octane. • The calcite nanoslits have a remarkable ability to store CO 2 even at high temperatures and pressures. CO 2 -Enhanced recovery has attracted extensive attention, meanwhile reducing greenhouse gas emissions via CO 2 geological sequestration is causing global concern in recent years, combining CO 2 -EOR and CO 2 sequestration has been recognized as one of the CCUS approach with high potential, and tight reservoirs such as shale oil are the most promising resource in this respect, which has become one of the hot topics unsurprisingly. The understanding about the microscopic molecular behaviors and interaction mechanisms between CO 2 , shale oil, and reservoirs is critical for the development of the techniques, while still incomplete, which makes it challenging for efficient large-scale application in the world. In this paper, molecular dynamics (MD) simulations are used to investigate the displacement and miscible behaviors of CO 2 /octane in calcite nanoslits under reservoir conditions, the effects of temperature, pressure and slit apertures on the molecular behaviors have been studied comprehensively. The interaction energy between CO 2 and octane molecules and calcite surface were calculated to quantitatively analyze the mechanisms in the process of CO 2 flooding. The significant strong interactions between calcite surface and CO 2 on one hand benefit the displacement of octane by CO 2 increasing the miscible flooding efficiency, on the other hand ensure the high adsorption capacity of CO 2 inside the calcite nanoslits, thereby plenty of CO 2 can be stored inside the calcite nanoslits after the flooding. It could be concluded that the carbonate reservoir could be the most promising field combining CO 2 -EOR and CO 2 sequestration. This work provides theoretical guidance for both the optimization of the CO 2 -enhanced oil recovery and effective CO 2 sequestration in unconventional tight reservoirs, especially carbonate reservoir. [ABSTRACT FROM AUTHOR]

• ScCO 2 -water interaction has significant influence on coal structures and mechanical properties. • Approximately 62.75–85.92% of aliphatic groups within coal are extracted by ScCO 2 -water. • The UCS is reduced by < 13% after ScCO 2 saturation on dry coal, but it is greatly decreased by 26.58–44.21% in the presence of water. • Water accelerates hydrocarbon extraction and mineral dissolution for mechanical degradation. Injection of CO 2 into deep unminable coal reservoirs is regarded as an effective method to reduce greenhouse gas emissions. Coal seams with burial depth > 800 m are the potential reservoirs for CO 2 sequestration, and CO 2 is stored in the form of supercritical state. The interactions between supercritical CO 2 (ScCO 2) and coal are a complex process, which has influence on coal structures and strength. Recent studies are rarely reported regarding the impact of ScCO 2 -coal-water reactions on coal microstructures and mechanical strength. In this paper, comparative analysis was conducted on the microstructural changes and mechanical degradation of coal induced by ScCO 2 treatment and ScCO 2 -water saturation. The results show that water has great influence on coal pore structure, functional groups, mineral compositions and mechanical properties during the reaction. ScCO 2 saturation only triggers a small decline of 11.27–17.65% in aliphatic groups in coal, while approximately 62.75–85.92% of aliphatic groups are extracted by ScCO 2 -water. The largest hysteresis loops are found in samples saturated by ScCO 2 -water, followed by the specimens treated by ScCO 2 , illustrating that the complexity of coal pore structure is enhanced by ScCO 2 interaction, and the presence of water can further increase the pore roughness. The UCS is reduced by < 13% after ScCO 2 saturation on dry coal, but it is greatly decreased by 26.58–44.21% in the presence of water. In the process of interaction, water accelerates the hydrocarbon extraction and mineral dissolution to aggravate the degradation of coal strength. This work is conducive to understanding the process of CO 2 geological sequestration. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influencing factors of MOFs for CO 2 capture and CO 2 -to-alcohols are discussed. • Strategies for improving the CO 2 capture of MOFs-based materials are introduced. • The catalytic systems used for CO 2 -to-alcohols are summarized. • The hydrogenation pathway of CO 2 -to-alcohols by MOFs-based materials are presented. • The challenges and trends of MOFs in CO 2 capture and conversion are prospected. The global climate change caused by the continuous increase of carbon dioxide (CO 2) emissions has seriously threatened the survival of human beings, so it is imperative to control its emission reduction and achieve its utilization. The adsorption of CO 2 and conversion into high-value-added chemicals can not only reduce the exhaust emission of greenhouse gas, but also help to solve the problems of excessive dependence on fossil fuels and the storage of renewable energy. As a promising carbon recycling technology, carbon capture and utilization (CCU) has attracted wide attention in the past decades. Various functional materials such as metal-organic frameworks (MOFs), metal oxides, molecular sieves and porous carbon materials have sprung up for CO 2 capture and conversion. MOFs have become a more promising candidate due to their highly tunable pore structure, easy surface functionalization and abundant active sites. This paper reviews most studies published in the last five years on MOFs used for capturing CO 2 and CO 2 -to-alcohols conversion. The main topics include 1) The influencing factors of MOFs-based materials for CO 2 capture and CO 2 -to-alcohols; 2) strategies to improve CO 2 adsorption performance and the role of high throughput computational screening (HTCS) on the development and screening of MOFs adsorbent; 3) MOFs-based materials used for CO 2 -to-alcohols conversion in photo-, electro-, thermal-catalytic and their hybrid catalytic systems, as well as the corresponding mechanistic studies. The purpose of this review is to offer a technical and theoretical direction for the creation and industrial implementation of high-performance MOFs-based materials in the field of CO 2 adsorption and conversion, highlight the associated challenges and opportunities. [ABSTRACT FROM AUTHOR]

Geological sequestration of CO 2 in unminable coal seams is one of the effective ways to reduce greenhouse gas emissions and increase coalbed methane production. However, changes in the pore structure after CO 2 injection may affect the mechanical properties of the coal reservoir, posing a challenge to the long-term safety of CO 2 sequestration. Therefore, a proper understanding of the relationship between pore structure and mechanical properties of coal under CO 2 treatment is essential. In this paper, Low-field nuclear magnetic resonance tests were carried out on bituminous coal after sub/super-critical CO 2 (Sub-CO 2 /Sc-CO 2) treatment, and uniaxial compression tests were used to analyze the mechanical properties and energy evolution of coal samples. The results demonstrate that the CO 2 treatment increased the porosity and proportion of macropores, and the effect of Sc-CO 2 treatment on the pore structure was more significant. Compared to the Sub-CO 2 treated sample, the uniaxial compressive strength and elastic modulus decreased more in the Sc-CO 2 treated sample, which may be related to the extraction capacity of Sc-CO 2. Analysis of the energy evolution shows that more energy was converted into dissipated energy in the loading process of Sc-CO 2 treated coal samples, which was used to form, expand and connect fractures. Moreover, the correlation between the rate of change in porosity and the rate of change in uniaxial compressive strength was 0.9579, indicating that changes in pore structure were the main cause of the change in the mechanical properties of coal. A conceptual model was proposed to explain the mechanism of the effect of the pore structure on the mechanical properties, and pressure selection during CO 2 sequestration was discussed. Therefore, the results of this study are expected to provide references for the long-term safety assessment and injection pressure selection of CO 2 sequestration. • The effect of Sc-CO 2 treatment on the pore structure is more significant. • Changes of pore structure is the main reason for changes of mechanical properties. • More energy was converted into dissipated energy of Sc-CO 2 treated coal samples. • A conceptual model was proposed to linke pore structures and mechanical properties. • Positive and negative effects of high-pressure injection method were discussed. [ABSTRACT FROM AUTHOR]

This paper examines leakage from agricultural greenhouse gas reduction programs stimulated by reductions in regional commodity supply. This paper develops an extension of the leakage discount formula in Murray et al. (2004) that incorporates changes in input (land) usage rather than product output (crop or forest product quantity). Additionally the leakage discount developed here allows for land conversion and production replacement involving multiple alternative uses. In an empirical application in the Southeast Texas we compute leakage discounts of 14.8% for the conversion of rice to no-till sorghum and 14.9% for rice to pasture program. Most of the sources of GHG offset leakage come from conversions of cotton to rice and pasture to rice in the other regions. [ABSTRACT FROM AUTHOR]

Abstract: This review paper discusses the perspectives for development of carbon capture and storage (CCS) technologies in the global fight against climate change, such as low-carbon technology which is a vital component to reduce future carbon emissions. The information on the level and growth of CO2 emissions, their source and geographic distribution, will be essential to lay the foundation for a global agreement; considering only for energy-related CO2, and not for any other greenhouse gases. We analyzed the distribution of the CO2 emission intensity related to them. Besides, in order to predict possible future situations of energy consumption, CO2 emissions intensity and the CCS role like the largest emission reduction potential, the International Energy Agency (IEA) has developed a number of scenarios; the baseline scenarios and comparative scenarios. We used the approach of the Blue Map Scenarios, bringing the 2005s emissions to a level of 50% by 2050 for a non-catastrophic human intervention in the climate system. Moreover, this paper shows the barriers, strategies for accelerating and the stages in the technology deployment. We also analyzed the CCS projects status; Challenges, SWOT analysis, and the currently Global CCS Technology Activity. For this, we consider the Large Scale Integrated Projects (LSIP), and the asset life-cycle model was used to categorize the status of a project according to its development stage. Alongside, the analysis involves: Total LSIPs by geographic region, by Industry and CO2 Capture Technology. In addition, we also made a scope on some of the most relevant international actions in order to stimulate the fulfillment of the CO2 intensity target. [Copyright &y& Elsevier]

Abstract Biochar-based carbon management networks (CMNs) offer a means of achieving negative net greenhouse gas (GHG) emissions. Such systems rely on relatively mature technologies for biochar production, distribution and application by tillage; thus, the prospects for near-term scale-up, especially in developing countries with agriculture-intensive economies, are promising. The main technological gap lies in the capability to predict, optimize and monitor the actual climate change mitigation benefits. Computer-aided planning of biochar-based CMNs will be needed to maximize GHG reductions while minimizing any potential adverse environmental impacts. Such models can help decision-makers to understand and optimize the cost/benefit aspects of such systems to accelerate their commercial deployment. This paper gives a brief review of the available scientific literature, and discusses prospective areas for further research to facilitate the large-scale use of biochar as a negative emissions technology (NET). Highlights • Biochar application to soil is a potentially scalable negative emissions technology. • Biochar-based carbon management networks can be operated based on this concept. • Computer-aided planning, optimization and monitoring are required. • An integrated modelling framework should be developed for effective decision support. [ABSTRACT FROM AUTHOR]

Abstract For many agricultural commodity sectors, efforts to meet international obligations regarding emissions reduction are increasing. The Australian cotton industry has already made advances in this regard and the high yields associated with Australian cotton production dramatically minimise greenhouse gas emissions intensity. However, certainty about the quantum of greenhouse gas emissions and the relative contribution of different components of the emissions profile is somewhat unclear; and opportunities for farm-level practice change have not been fully explored. The objectives of this paper were to, (a) build a robust greenhouse gas emissions profile for the product-chain of Australian cotton fibre (lint) grown in northwest New South Wales, (b) using Life Cycle Assessment (LCA), compare the relative contributions of the different industries involved in the product-chain of cotton fibre (e.g. fertiliser producers, cotton farmers, cotton ginning plants) and (c) assess the effects of an array of on-farm mitigation options. Testing the various management options provides information for growers and policy-makers about the relative emissions reduction benefits possible. Additionally, we compared results of previous Australian cotton production studies using similar assumptions and extrapolated the emissions profile to a national scale, with the intention of informing commodity and carbon markets. The foreground data for the study were for the three production seasons from 2011-2012 to 2013–2014 in northwest New South Wales, with a functional unit of one tonne of cotton lint at port. We also drew upon published data, survey data, scientific literature and Australian and international databases. To ensure consistency between our approach and that applied to meet international emissions reporting obligations, we applied emissions formulae and factors from the Australian National Inventory Report, except where more specific published data were available. We assumed that 96% of production was from irrigated systems, with 85% of irrigation water pumped by diesel-powered irrigation pumps and a median irrigated yield of 10.3 bales per ha. We tested the sensitivity of the resulting emissions profile to a wide array of enterprise assumptions and calculation variables. The climate change impact of cotton lint on a cradle-to-port basis was 1601 kg CO 2 e per tonne of cotton lint. The 'hot-spots' within the emissions profile included the production and use of synthetic nitrogen (N) fertilisers (46% of emissions), the production and use of electricity and diesel used for irrigation (10%) and the production and use of diesel for farm machinery (9%). Farm level management options with potential to minimise life cycle GHG emissions were: reducing N fertiliser rate from a commercial rate of 255 kg N/ha to 240 kg N/ha or 180 kg N/ha (2.6% and 13.2% emissions reduction); use of controlled-release and stabilised N fertilisers (5.9% reduction), changing from diesel to solar-powered irrigation pumps (8.1% reduction), changing from diesel to biofuel-powered farm machinery (3.4% reduction), changing from continuous cotton to a cotton-legume crop rotation (3.9% reduction) and use of N fertigation (2.1% reduction). Whilst we focused on farm-level mitigation strategies, these changes were placed in the context of the cradle-to-gate system, to account for associated changes in pre-farm and post-farm emissions. Graphical abstract Image Highlights • Greenhouse gas emissions from cotton production were calculated as 1601 kg CO2e per tonne of cotton lint delivered to port. • Sensitivity testing was conducted to ascertain the robustness of the present study. • Previous findings were adjusted on the basis of the assumptions established for this study. • Greenhouse gas emissions mitigation strategies were evaluated and compared. [ABSTRACT FROM AUTHOR]

Abstract: Ecosystem services (ES) are provided by healthy ecosystems and are fundamental to support human life. However, natural systems have been degraded all over the world and the process of degradation is partially attributed to the lack of knowledge regarding the economic benefits associated with ES, which usually are not captured in the market. To valuate ES without using conventional approaches, such as the human''s willingness-to-pay for ecosystem goods and services, this paper uses a different method based on Energy Systems Theory to estimate prices for biogeochemical flows that affect ecosystem services by considering their emergy content converted to equivalent monetary terms. Ecosystem services related to water, carbon and nitrogen biogeochemical flows were assessed since they are connected to a range of final ecosystem services including climate regulation, hydrological regulation, food production, soil formation and others. Results in this paper indicate that aquifer recharge, groundwater flow, carbon dioxide sequestration, methane emission, biological nitrogen fixation, nitrous oxide emission and nitrogen leaching/runoff are the most critical biogeochemical flows in terrestrial systems. Moreover, monetary values related to biogeochemical flows on a global scale could provide important information for policymakers concerned with payment mechanisms for ecosystem services and costs of greenhouse gas emissions. [Copyright &y& Elsevier]

Abstract: This paper presents an overview of the wellbore integrity research component of the IEA GHG Weyburn-Midale CO2 Monitoring and Storage Project. The Weyburn and Midale fields are located adjacent to one another in southeast Saskatchewan, Canada, and have been undergoing full-scale CO2 flooding starting in 2000 and 2005, respectively. Given that there are over four thousand wellbore penetrations in these fields, combined, effective implementation of CO2 storage requires an understanding of the hydraulic properties of these wellbores, their response to CO2 exposure, appropriate tools for monitoring their performance, and knowledge of appropriate remediation options. The objectives of the wellbore integrity research program in this project are all oriented towards developing an understanding of these issues, and towards documenting this information in the Project’s Best Practices Manual. Research activities summarized in this paper include an overview of a downhole testing program which is planned for October 2010, a review of literature and regulatory policies on current practices in oil and gas production and injection which are relevant to wellbore integrity in CO2 storage projects, and the development of a wellbore database and its use in support of a ranking system to classify wells based on their potential for leakage and a ‘life of well’ numerical modelling project. [Copyright &y& Elsevier]

Abstract: CO2 avoidance cost economics are an essential tool for analysis of the potential for future CO2 capture and storage (CCS) utilization. The CO2 avoidance cost is the CO2 tax at which the product cost is the same for either a fossil fuel plant without CO2 mitigation (but paying the CO2 tax) or the same fossil fuel plant that includes the added capital and efficiency losses of adding CCS (but avoiding most of the CO2 tax). The CO2 tax must be higher than this CO2 avoidance cost to justify the higher risks, capital, and lower efficiency of utilizing CCS. Understanding which issues impact CO2 avoidance costs the most is fundamental to economically encouraging the massive CO2 reductions enabled with CCS. SFA Pacific recently completed two similar economic analyses of coal-based power plant CO2 mitigation costs. Both analyses included the options of converting to lower CO2 emissions with natural gas (with and without CCS) and continued coal use with and without CCS. One analysis was for an existing coal-based power plant baseline as part of a Massachusetts Institute of Technology (MIT) Workshop and Report entitled Retrofitting of Coal-Fired Power Plants for CO2 Emissions Reductions . The second analysis was for a new coal-based power plant baseline as part of an analysis of CO2 mitigation options by the U.S. Business Roundtable entitled The Balancing Act: Climate Change, Energy Security and the U.S. Economy . However, the resulting CO2 avoidance costs for these two analyses were very different. Specifically, the CO2 avoidance cost was about twice as high for the existing coal power plant than for the new coal power plant baseline. There are basic technical and economic reasons for this big difference in CO2 avoidance costs. They are best explained by simply showing the costs and performance of each baseline without and then with CCS in simple, transparent, and consistent one-page models. This enables easy, insightful side-by-side direct comparisons. Since first developing a cost and performance economic screening model of CCS for our GHGT-4 paper in 1998 , SFA Pacific has continued to improve the model which focuses on objectivity by stressing transparency and consistency with easy to compare cases. SFA Pacific has clearly shown identical inputs for key items such as fuel costs, non-fuel operating costs, unit capital costs, contingencies, site location factors, cost indexes, and especially capital charges. This makes it easy to see that power costs for the existing coal power plant baseline can be very low when the power plant is old and most of the existing capital is already paid-off. This GHGT-10 paper presents the most updated SFA Pacific analysis of CCS retrofit for existing coal power plant CO2 mitigation. The paper focuses on showing and explaining why the CO2 avoidance costs can be much higher for the existing plants versus new fossil fuel power plants. CO2 taxes which are high enough to discourage new coal power plants with high CO2 emissions would likely have little or no impact on existing coal power plants. Until the over 1,200 GW of existing old coal power plants begin reducing their high CO2 emissions, there can be little net reduction in worldwide CO2 growth. Converting or replacing this large capacity of existing coal power plants is essential to obtaining large CO2 reductions . [Copyright &y& Elsevier]

Abstract: Integrated Gasification Combined Cycle (IGCC) is a power generation technology in which the solid feedstock is partially oxidized with oxygen and steam to produce syngas. In a conventional IGCC design without carbon capture, the syngas is purified for dust and hydrogen sulphide removal and then sent to a Combined Cycle Gas Turbine (CCGT) for power generation. Carbon capture technologies are expected to play an important role in the coming decades for reducing the greenhouse gas emissions. In a modified IGCC design for carbon capture, the syngas is catalytically shifted to maximize the hydrogen level and to concentrate the carbon species in the form of carbon dioxide which can be later captured in a pre-combustion arrangement. After carbon dioxide capture, the hydrogen-rich syngas can be either purified in a Pressure Swing Adsorption (PSA) unit and exported to the external customers (e.g., chemical industry, PEM fuel cells) or used in a CCGT for power generation. This paper investigates the most important energy and process integration issues for hydrogen and electricity co-production scheme based on coal gasification process with carbon capture and storage (CCS). The evaluated coal-based IGCC case produces around 400 MW net electricity and has a flexible hydrogen output in the range of 0–200 MW (LHV) with a 90% carbon capture rate. The principal focus of the paper is on the evaluation of energy integration aspects so as to maximize the overall plant energy efficiency. Optimization includes heat and power integration of the main plant sub-systems (e.g., integration of steam generated in gasification island, with the requirements for syngas treatment, power generation in the combined cycle, best use of PSA tail gas in the power block, heat and power demand for acid gas removal unit, integration of air separation unit and gas turbine compressor etc.), sensitivity analysis (e.g., influence on ambient conditions). [Copyright &y& Elsevier]

The reduction of anthropogenic greenhouse gas emission rates alone appears insufficient to limit the rise in global temperatures. Negative Emission Technologies (NETs) can be helpful in this critical goal by actively removing CO 2 from the atmosphere. Industrialised countries like Scotland will require NETs to address their climate targets and reach net-zero carbon emissions in a timely manner. However, the implementation of NETs has varied energy, economic and environmental implications that need to be analysed in detail. In this paper, we explore the potential energy and economic costs for implementation of land-based NETs in Scotland. This analysis is based on the calculated averaged costs of the different technologies and the availability of resources for its implementation in Scotland. We found that the country has a maximum technical potential to abate 90–100% of its annual CO 2 emissions by means of land-based NETs, thanks to its low annual emissions and large land area for implementation of NETs. Even in less optimistic scenarios, Scotland is exceptionally well suited for land NETs, which can complement and enhance the potential of more conventional technologies, like renewable energy resources. Our results show that Scotland could lead the transformation towards a carbon-neutral society. [ABSTRACT FROM AUTHOR]

To maximize safety and cost-efficiency of CO 2 storage, it is necessary to understand how a high permeability in the near-well region can be maintained. All the injected CO 2 needs to pass through this zone before entering the reservoir, and pore clogging/closing here can cause fracturing and channelling of the formation – and will require costly mitigation measures. Recent storage pilots have reported incidents of permeability loss during injection, and these have been ascribed to salt precipitation, bacterial activity, and pressure/temperature variations caused by starts and stops in the injection pattern. As we move to larger scale CO 2 storage projects (gigatonnes/year), a higher number of wells and larger quantities of CO 2 will be dealt with. This means that injectivity issues will become more frequent – and thus have a greater impact on Carbon Capture and Storage (CCS) project economics. Until now, salt precipitation has completely dominated the field of injectivity – and is by far the most studied loss mechanism. In the present publication, we show that there are other important injectivity loss mechanisms that should not be overlooked. These are fines migration, geomechanical factors (e.g. borehole deformation), geochemical factors (e.g. clay content) and rock heterogeneity. We summarize laboratory and field studies of these topics, and discuss their relevance for CO 2 injectivity – particularly in unconsolidated sands. The paper reviews when such injectivity problems occur in the context of CO 2 injection, and how they can be prevented and mitigated. [ABSTRACT FROM AUTHOR]

Combatting climate change has risen to the top of the international policy discourse. Effective governance necessitates the generation of concise information on the costs-effectiveness of policy instruments aimed at reducing atmospheric greenhouse gas (GHG) emissions. The marginal abatement cost curve (MACC) approach is a framework commonly used to summarise information of potential mitigation effort, and can help in identifying the most cost-effective managerial and technological GHG mitigation options. Agriculture offers key opportunities to mitigate GHG emissions and utilise carbon (C) sink potentials. Therefore, a number of countries have developed national agricultural MACCs in the last decade. Whilst these MACCs have undoubtedly been catalysers for the information exchange between science and policy, they have also accentuated a range of constraints and limitations. In response, each of the scientific teams developed solutions in an attempt to address one or more of these limitations. These solutions represent ‘lessons learned’ which are invaluable for the development of future MACCs. To consolidate and harness this knowledge that has heretofore been dispersed across countries, this paper reviews the engineering agricultural MACCs developed in European countries. We collate the state-of-the-art, review the lessons learnt, and provide a more coherent framework for countries or research groups embarking on a trajectory to develop an agricultural MACC that assesses mitigations both within the farm gate and to the wider bioeconomy. We highlight the contemporary methodological developments, specifically on 1) the emergence of stratified MACCs; 2) accounting for soil carbon sequestration 3) accounting for upstream and downstream emissions; 4) the development of comprehensive cost-calculations; 5) accounting for environmental co-effects and 6) uncertainty analyses. We subsequently discuss how the mitigation potential summarised by MACCs can be incentivised in practice and how this mitigation can be captured in national inventories. We conclude that the main purpose of engineering MACCs is not necessarily the accurate prediction of the total abatement potential and associated costs, but rather the provision of a coherent forum for the complex discussions surrounding agricultural GHG mitigation, and to visualise opportunities and low-hanging fruit in a single graphic and manuscript. [ABSTRACT FROM AUTHOR]

Mexico has a strong commitment to reduce its greenhouse gas (GHG) emissions. The electrical and the industrial sectors have been the second and third largest contributors to GHG emissions–excluding fugitive emissions-. This paper analyzes the potential contributions of Carbon Capture and Storage (CCS) systems on the electrical sector, as well as the participation of the cement, metal and chemical industries. This study was carried out using a computational mathematical model, the MEM70, which is a partial equilibrium model that represents the Mexican energy system. It was found that, even considering energy efficiency measures, a high penetration of electric vehicles and the electrical sector with high participation of low carbon emission technologies such as renewable and nuclear sources. Further, it is necessary to implement CCS to achieve the goal for reducing national greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

As greenhouse gas emissions are a key driver of climate change, sources of CO 2 must be mitigated, particularly from carbon-intensive sectors, like power production. Natural gas provides an increasingly large percentage of electricity; however its lower carbon intensity is insufficient to make proportional reduction contributions to circumvent 2 °C global warming. The low partial pressure of CO 2 in its flue gas makes post-combustion capture more challenging – increasing the CO 2 in the exhaust assists in enhancing capture efficiency. This paper experimentally investigates the impact of the combination of humidified air turbines and exhaust gas recirculation to increase CO 2 partial pressures, with the aim of evaluating their effects on emissions and turbine parameters at various turndown ratios. It was found that CO 2 levels could be increased from 1.5 to 5.3 vol%, meaning more efficient post-combustion capture would be possible. CO 2 and steam additions increased incomplete combustion when used together at high levels for low turndown ratios (below 60%), with CO increasing from 49 to 211 ppm and CH 4 from 2.5 to 52 ppm; this effect was negated at higher power outputs. Turbine cycle humidification resulted in net improvements to the turbine efficiency, by up to 5.5% on a specific fuel consumption basis. [ABSTRACT FROM AUTHOR]

Summary This paper uses 620 forest plot measurements taken from a nationally representative sample of 130 Nepal community forests combined with information on forest collective action to estimate the effects of collective action on carbon per hectare and three additional measures of forest quality. We use three measures of forest user group collective action, including membership in the Nepal Community Forestry Programme (CFP). Collective action shows large, positive, and statistically significant carbon effects vis-à-vis communities exhibiting no evidence of forest collective action, which do not necessarily correspond with results for other measures of forest quality. We find that depending on the collective action definition and physiographic region, forests controlled by communities exhibiting no evidence of forest collective action may have as little as 34% of the carbon of forests governed under collective action. We do not, however, find evidence that CFP forests, our narrowest measure of collective action, store more carbon than forests outside the CFP. Our results therefore suggest that it is the collective action behavior and not the official CFP label that offers the largest gains. Carbon benefits from collective action are therefore not found to be conditional on CFP participation. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) has been globally gaining popularity as a viable greenhouse gases mitigation strategy throughout the last decade. Calcium looping (CaL) is an emerging technology to capture carbon dioxide from flue gases of fossil fueled power plants exploiting the reversible gas-solid reaction between the carbon dioxide (CO 2 ) and calcium oxide (CaO) to form calcium carbonate (CaCO 3 ) in a fluidized bed. In this paper, the concept of calcium looping application using alternating fluidized beds is explored as well as a proposed scheme to allow smooth gas switching between reactors using an intermediate third reactor. The latter scheme enables energy saving as well. A dynamic model of a bubbling bed carbonator, the key reactor in the capture process, is presented. The model incorporates both hydrodynamics and chemical kinetics to provide more reliable predictions. The model has been validated with experimental results obtained at combustion lab, Mansoura University, Egypt using an atmospheric fluidized bed reactor of 10.5 cm inner diameter. The key parameters have been investigated to check for system sensitivity. Bed temperature has a non-monotonic effect on CO 2 capture efficiency. Maximum CO 2 capture efficiency was found to occur around a temperature of 675 °C. Capture efficiency increases with either decreasing fluidization velocity or increasing bed particle size due to enhanced mass transfer and increased residence time. These findings almost accord with published data. Also, the average CO 2 capture efficiency was found to increase with increasing static bed height up to a certain limit. Further increase in bed height doesn’t considerably affect the capture efficiency. The proposed model can be used as a design tool that would enable the optimization and commercialization of calcium looping. [ABSTRACT FROM AUTHOR]

This paper investigates the cost reduction opportunity of lower CO 2 capture ratios (CCR) on membrane-based CO 2 capture. A numerical model based on the attainable region approach is used to optimise and assess the cost of membrane-based processes for CO 2 capture from post-combustion flue gases containing 10–35% CO 2 , analysing five membranes and CO 2 capture ratios from 50 to 90%. Overall, these cost evaluations demonstrate that membrane-based post-combustion CO 2 capture can significantly benefit from lower CCRs (up to 55% reduction in CO 2 avoidance cost for a flue gas containing 35% CO 2 ). Considering lower CCRs could therefore enable early deployment of CCS despite low carbon emission cost, however the evaluations show that the optimal CCR and corresponding cost reduction potential shall be assessed considering the whole chain characteristics (CO 2 content in the flue gas, impurities, membrane module properties, CO 2 transport system, etc.). [ABSTRACT FROM AUTHOR]

In this paper, an integrated power generation system of Kalina cycle system (KCS) and organic Rankine cycle (ORC) with LNG cold energy exploitation and CO 2 capture is introduced. The composite circulation system can fully recover and use the medium and low temperature waste heat to reduce the greenhouse gas emissions. To evaluate the system performances, the thermodynamics model was established and the system was simulated by using Aspen HYSYS software. Thermodynamic analysis has been performed to study the effects of turbine inlet temperature, NH 3 mass fraction, evaporation pressure and CO 2 capture pressure on the KCS/ORC integrated system. The optimal conditions were also investigated and identified. Exergy analysis of the components operated on KCS or ORC has also been demonstrated. The results showed that the optimal values of the network output, thermal efficiency and CO 2 captured quantity of the system were respectively 394.685 kW, 53.25% and 0.3 t/t CO2 (0.6 t/t LNG ), while the evaluation indexes of the power recovery efficiency and exergy efficiency were respectively 36% and 41.42%. The exergy loss efficiency of each component was examined. It was indicated that the whole system has significant advantages in waste heat recovery. [ABSTRACT FROM AUTHOR]

Agriculture and forestry activities are one of the many sources of greenhouse gas (GHG) emissions, but they are also sources of low-cost opportunities to mitigate these emissions compared to other economic sectors. This paper provides a first estimate of the potential for mitigation in the whole Spanish agriculture. A set of mitigation measures are selected for their cost-effectiveness and abatement potential and an efficient mix of these measures is identified with reference to a social cost of carbon of 40 €/tCO 2 e. This mix of measures includes adjusting crop fertilization and managing forests for carbon sequestration. Results indicate that by using the efficient mix of mitigation measures the annual abatement potential could reach 10 million tCO 2 e, which represents 28% of current agricultural emissions in Spain. This potential could further increase if the social cost of carbon rises covering the costs of applying manure to crops. Results indicate also that economic instruments such as input and emission taxes could be only ancillary measures to address mitigation in agriculture. These findings can be used to support the mitigation efforts in Spain and guide policymakers in the design of country-level mitigation strategies. [ABSTRACT FROM AUTHOR]

Carbon capture and sequestration technology is a major approach developed to mitigate the amount of greenhouse gases released into the atmosphere. Technically, depleted oil and gas reservoirs are one of the feasible subsurface geologic media for large-scale carbon dioxide (CO 2 ) storages. Trapping mechanisms during and after CO 2 injection in geologic formations ensure the long-term safety and security of a storage task. However, depending on characteristics of geologic sites and subsurface conditions, different trapping mechanisms may come to play during sequestration, among which residual trapping is by far the most efficient one in a short-term scale. Although there have been many experimental and numerical studies carried out in the past years to evaluate this trapping potential prior to injection, there is not any field-scale approaches developed to assess CO 2 residual trapping at the depletion stage of oil and gas reservoirs. The aim of this paper is to present a method for residual trapping assessment of CO 2 storage sites by considering related and effective constraints such as residual hydrocarbon saturation, interfacial tension, pore geometry, and wettability. An analytical method based on a adjustment factor was proposed which could be used to determine the residual CO 2 saturation/residual trapping for different rock types having different wetting characteristics. Two wells out of a total number of 20 wells (mostly depleted) from the largest gas field in Malaysia were considered as part of this study to show how the proposed method can be executed in the field scale for determination of the residual trapping ability of the reservoir. The results obtained indicated that the average residual CO 2 saturation by the proposed method is around 26% and 27% for Well A and Well B, respectively. Thus, the maximum volume of CO 2 residual trapped could be approximately 0.96 Tscf or 0.97 Tscf of the effective pore volume (excluding 30% Sgr), based on the average saturations estimated from the data of Well A and Well B. The results were validated both experimentally and numerically where it was found that the proposed method and three phase core flooding experimental data are in good agreement, indicating a strongly water wet system. However, more experimental studies on the core samples taken from the same field are required to further validate the results before fully implementing CO 2 storage in the site. [ABSTRACT FROM AUTHOR]

To alleviate the negative influence caused by curtailment of renewable energy resulting from the "power determined by heat" of CHP, recent studies have proposed hybrid concentrated solar power and combined heat and power (CSP-CHP) to provide additional flexibility to power system to reduce renewable energy curtailment. However, for the power system with high wind power penetration in the future, hybrid CSP-CHP can only partially absorb wind power, and the CO2 emission from isolated CHP can also cause environmental pollution. Therefore, this paper extends the coupled power to gas (P2G) and carbon capture and storage (CCS) technologies to the hybrid CSP-CHP integrated energy system (IES), aiming to accommodate more wind power and further reduce CO2 emissions. First, the operation mechanism and mathematical model of the proposed integrated energy system are developed. Second, considering the increase in wind power permeability, a low carbon economic dispatch model to minimize economic cost is presented to optimize the proposed IES operation. Finally, in order to verify the validity of the proposed IES, different cases are compared in the simulation. The simulation result shows that the proposed IES has an excellent performance in wind power absorption and CO2 emission reduction. The proposed model emission is less than the base case by 72.4%, and greatly improve the level of wind power absorption. • Hybrid concentrated solar power and combined heat and power is used in energy system. • Power-to-Gas technology and Carbon Capture System are coupled in proposed system. • The system is put into a day ahead dispatch considering electro-thermal-gas trade. • 100% wind power absorption and 72.4% CO2 emission reduction are realized. [ABSTRACT FROM AUTHOR]

This paper assesses the impact of an EU-wide policy to expand grassland areas and promote carbon sequestration in soils. We use the economic Common Agricultural Policy Regionalized Impact (CAPRI) model, which represents EU agriculture using 2450 mathematical programming farm-type models in combination with the biogeochemistry CENTURY model, which provides carbon sequestration rates at a high resolution level. Both models are linked at the NUTS3 level using location information from the Farm Accounting Data Network. We simulated a flexible grassland premium such that farmers voluntary and cost efficiently increase grassland area by 5%. We find that the GHG mitigation potential and the costs depend on carbon sequestration rates, land markets and induced land use changes, and regional agricultural production structures. In Europe, the calculated net effect of converting 2.9 Mha into grassland is a reduction of 4.3 Mt CO2e (equivalents). The premium amounts to an average of EUR 238/ha, with a total cost of EUR 417 million for the whole EU. The net abatement costs are based on the premium payments, and account on average EUR 97/t CO2e. However, substantial carbon sequestration (28% of total sequestration) can be achieved at a rate of EUR 50/t CO2e. Carbon sequestration would be most effective in regions of France and Italy and in Spain, the Netherlands and Germany. Larger farms and farm-types specialized in ‘cereals and protein crops’, ‘mixed field cropping’ and ‘mixed crop-livestock’ farming systems have the highest mitigation potential at relatively low costs. [ABSTRACT FROM AUTHOR]

Power generation is one of the largest anthropogenic greenhouse gas emission sources; although it is now reducing in carbon intensity due to switching from coal to gas, this is only part of a bridging solution that will require the utilization of carbon capture technologies. Gas turbines, such as those at the UK Carbon Capture Storage Research Centre's Pilot-scale Advanced CO 2 Capture Technology (UKCCSRC PACT) National Core Facility, have high exhaust gas mass flow rates with relatively low CO 2 concentrations; therefore solvent-based post-combustion capture is energy intensive. Exhaust gas recirculation (EGR) can increase CO 2 levels, reducing the capture energy penalty. The aim of this paper is to simulate EGR through enrichment of the combustion air with CO 2 to assess changes to turbine performance and potential impacts on complete generation and capture systems. The oxidising air was enhanced with CO 2 , up to 6.29%vol dry, impacting mechanical performance, reducing both engine speed by over 400 revolutions per minute and compression temperatures. Furthermore, it affected complete combustion, seen in changes to CO and unburned hydrocarbon emissions. This impacted on turbine efficiency, which increased specific fuel consumption (by 2.9%). CO 2 enhancement could therefore result in significant efficiency gains for the capture plant. [ABSTRACT FROM AUTHOR]