Search

Alcohol-blended gasoline is recognized as an effective strategy for reducing carbon emissions during combustion and enhancing fuel performance. However, the carbon footprint associated with its production process in refineries deserves equal attention. This study introduces a refinery modeling framework to evaluate the long-term economic and environmental performance of utilizing alcohols derived from fossil, biomass, and carbon capture sources in gasoline blending processes. The proposed framework integrates Extreme Learning Machine-based models for gasoline octane blending, linear programming for optimization, carbon footprint tracking, and future trends in feedstock costs and carbon taxes. The results indicate that gasoline blended with coal-based alcohol currently exhibits the best economic performance, though its carbon footprint ranges from 818.54 to 2072.89 kgCO2/t. Gasoline blended with biomass-based alcohol leads to a slight reduction in benefits and an increase in the carbon footprint. Blending gasoline with CCUM (CO2 capture and utilization to methanol) results in the lowest economic performance, with a gross margin of 8.91 CNY/toil at a 30% blending ratio, but achieves a significant 62.4% reduction in the carbon footprint. In long-term scenarios, the additional costs brought by increased carbon taxes result in negative economic performance for coal-based alcohol blending after 2040. However, cost reductions driven by technological maturity lead to biomass-based alcohol and CCUM blending gradually showing economic advantages. Furthermore, owing to the negative carbon emissions characteristic of CCUM, the blending route with CCUM achieves a gross margin of 440.60 CNY/toil and a gasoline carbon footprint of 282.28 kgCO2/t at a 20% blending ratio by 2050, making it the best route in terms of economic and environmental performance. [ABSTRACT FROM AUTHOR]

The refining industry is shifting from decarbonization to hydrogenation for processing heavy fractions to reduce pollution and improve efficiency. However, the carbon footprint of hydrogen production presents significant environmental challenges. This study couples refinery linear programming models with life cycle assessment to evaluate, from a long-term perspective, the role of low-carbon hydrogen in promoting sustainable and profitable hydrogenation refining practices. Eight hydrogen-production pathways were examined, including those based on fossil fuels and renewable energy, providing hydrogen for three representative refineries adopting hydrogenation, decarbonization, and co-processing routes. Learning curves were used to predict future hydrogen cost trends. Currently, hydrogenation refineries using fossil fuels benefit from significant cost advantages in hydrogen production, demonstrating optimal economic performance. However, in the long term, with increasing carbon taxes, hydrogenation routes will be affected by the high carbon emissions associated with fossil-based hydrogen, losing economic advantages compared to decarbonization pathways. With increasing installed capacity and technological advancements, low-carbon hydrogen is anticipated to reach cost parity with fossil-based hydrogen before 2060. Coupling renewable hydrogen is expected to yield the most significant economic advantages for hydrogenation refineries in the long term. Renewable hydrogen drives the transition of refining processing routes from a decarbonization-oriented approach to a hydrogenation-oriented paradigm, resulting in cleaner refining processes and enhanced competitiveness under emission-reduction pressures. [ABSTRACT FROM AUTHOR]

Climate change severely affects urban water systems (UWSs). Infrastructure historically designed for milder conditions cannot manage growing water demands and extreme events. To obtain a resilient water sector, adaptation and mitigation strategies must address rising water challenges while striving for net-zero emissions. Researchers have noted that extreme decentralization is positively associated with closing cycles while reducing transport costs. However, part of the scientific community defends centralized schemes due to economies of scale. The objective of this systematic review is to understand the trade-offs associated with the adoption of different scales at UWSs design and how this impacts system resilience. This process includes identifying different scale trade-offs and unique environmental aspects that influence the optimal scale suitability. A clear distinction was made in terms of scale concept and classification, considering different design levels. That is, considering the UWS at the city level and water management units (WMUs) at the local level. Similarly, a classification of different scales for each level, covering all water streams—supply, wastewater, and stormwater—was introduced. We defined the key environmental aspects that influence the optimal scale and location suitability: ten at the city-catchment level and eleven at the site-neighbourhood level. Scale impacts three major UWSs functionalities that have repercussions on urban resilience: net energy, net water, and ecosystem services (ES). [ABSTRACT FROM AUTHOR]

Oilfield brine is the largest byproduct stream generated during the extraction of crude oil and natural gas and may be considered a resource for the production of potable water and valuable raw materials. The high salinity of such waters limits the application of typical membrane-based techniques. In most oilfields, waste cold energy from the process of the low-temperature separation of natural gas is available and may be used as a source of cold for the freezing desalination (FD) of brine. As a result of the FD process, two streams are obtained: partially desalinated water and concentrated brine. The partially desalinated water may be suitable for non-potable applications or as a feed for membrane desalination. The concentrated brine from the FD could be used as a feed for the recovery of selected chemicals. This paper focuses on verifying the above-described concept of the freezing desalination of oilfield brine on a laboratory scale. The brine from a Polish oilfield located in the Carpathian Foredeep was used as a feed. Four freezing–thawing stages were applied to obtain low-salinity water, which subsequently was treated by reverse osmosis. The obtained permeate meets the criteria recommended for irrigation and livestock watering. The concentrated brine enriched with iodine (48 mg/L) and lithium (14 mg/L) was subjected to recovery tests. Ion exchange resin Diaion NSA100 allowed us to recover 58% of iodine. Lithium recovery using Mn- and Ti-based sorbents varies from 52 to 93%. [ABSTRACT FROM AUTHOR]

Around 65% of the mitigation needed for the targeted net-zero carbon aviation emissions in 2050 is expected to come from Sustainable Aviation Fuels (SAFs). In this study, an alternative gasification-driven Biomass-to-Liquid (BtL) concept for the production of SAFs is introduced and evaluated. In particular, a fuel synthesis scheme based on the double-stage fermentation of the produced syngas (syngas → acetic acid → TAGs) is assessed instead of the conventional Fischer-Tropsch (FT) or Alcohol-to-Jet (AtJ) synthesis. The objective of the present work is the techno-economic evaluation of a large-scale (200 MWth) replication of the mentioned BtL concept, whose performance has been simulated in Aspen PlusTM (V.11) with reasonable upscaling considerations and models validated at a pilot scale. The estimated baseline Total Capital Investment (TCI) of €577 million lies in the typical range of €500–700 million that many recent techno-economic studies adopt for gasification-driven BtL plants of similar capacity, while the estimated annual operating costs of €50 million correspond to a 15–40% OpEx reduction compared to such plants. A discounted cash flow analysis was carried out, and a baseline Minimum Jet Selling Price (MJSP) equal to 1.83 €/L was calculated, while a range of 1.38–2.27 €/L emerged from the sensitivity analysis. This study sets the biological conversion of gasification-derived syngas into triglycerides (TAGs) as a promising alternative route for the production of SAFs. In general, gasification-driven BtL pathways, led by the relatively mature FT and AtJ technologies, are capable of thriving in the coming years based on their capability of advanced feedstock flexibility. [ABSTRACT FROM AUTHOR]

Attention to greenhouse gases is carried out by reducing CO2 emissions. Emission reduction is achieved using mixed fuels, primarily derived from plant oils. The pertasol-diethyl ether and tamanu oil (PDETO) fuel mixture were tested using a spark ignition engine. The research objective is to obtain fuel specifications and test engine performance using the resulting fuel. Mixed fuels were created from various compositions with codes ranging from BE0 to BE10. Performance testing was conducted using a 110-cc gasoline engine with specific specifications using mixed fuels and compared to commercial gasoline. The research results indicate that engine torque, power, and MeP are higher when using mixed fuels BE0 - BE10 than retail gasoline. The maximum torque that can be achieved is 8.51 NM at 5000 rpm using BE10 mixed fuel, higher than the maximum torque of commercial gasoline, which is 6.81 NM. The highest full power is generated by BE10 fuel, at 7.75 HP at an engine speed of 7000 rpm. The minimum capacity is produced by BE0 fuel, with a power of 6.78 HP at an engine speed of 7000 rpm. Optimal SFC occurs in the BE0 fuel mixture at 7000 rpm engine speed at 0.25 kg/Hp·h. BE10 thermal efficiency reached 31.8%, which is better than commercial gasoline. [ABSTRACT FROM AUTHOR]

Spain, in the framework of the European Green Deal, has set ambitious climate and energy goals for 2030. Lignocellulosic biorefineries can make a strong contribution to these goals; however, advanced biofuels generally cannot be produced in a profitable way compared to fossil and first-generation fuels. To address this problem, the efficient production of a wide range of bioproducts, not only biofuels and bioenergy, may be the solution. Therefore, a systematic evaluation of the near-term economic potential bio-building blocks (xylitol, sorbitol, succinic, glutamic, glucaric, levulinic, lactic, and itaconic acids) is presented. Many possible combinations of feedstock and conversion technologies can be considered feasible pathways to manufacture advanced biofuels and bio-based building blocks. To map the optimal groups of technologies in the framework of Spain's biorefineries, we apply a methodology based on a network optimization approach that combines minimum cost and energy criteria together with feedstock availability and demand constraints. The feedstocks analyzed are pine and eucalyptus residues and olive tree pruning wastes, being three largely available agroforesty residues in Spain. The results show that building blocks show good economic and energy performance compared to advanced transportation biofuels, and although their demand is much lower, they should be considered to improve the profitability of biorefineries. Secondly, advanced gasoline, bioethanol, hydrogen, and building blocks demands can be satisfied with pine, eucalyptus, and olive residues available in Spain. Finally, lactic acid production is profitable, but the remaining routes do not reach the break-even point, suggesting that further research is still needed. [ABSTRACT FROM AUTHOR]

The air quality in petroleum refineries is one of the most critical factors in the petroleum refining processes. Several parameters in the air usually have a direct influence on human health and the environment, including poisoning gases, vapors, and particulate matter (PMs). In the present study, the air quality was evaluated in petroleum refineries sites to provide more understanding of the effect of the presence of such polluted materials on the environment and the operator's health in the refinery. It was found that petroleum refineries produce a series of fatal compounds such as sulfur compounds hydrocarbons (gases and vapors), and PM0.1, PM2.5, and PM10. All these materials have a solid impact on human health. It was found that they used many types of air filters, such as personal masks or central air filtration units reducing the concentration of such polluted material dramatically. Also, the results showed that the used crude oil (API) and sulfur contents are the main two important factors that reflect air quality. The high API crude oil with low sulfur compounds produces low polluted material in the air. Moreover, it was found that the modern refineries that used Euro-5 (eco-friendly design) produced fewer emissions with a cleaner environment in comparison with old versions of the refining design. [ABSTRACT FROM AUTHOR]

A lot of research has been carried out to improve the sustainability of seawater desalination. Despite progress, relatively few studies have analyzed the sustainability of seawater desalination processes integrated on two fronts, i.e., (i) process integration and (ii) energy integration. In addition, life cycle assessment studies on multi-stage flash (MSF) desalination often neglect the impact of the disposed brine by assuming that dilution of the discharged brine impacts on ecological systems less. The present study contributes to these omissions by exploring the environmental sustainability of seawater desalination systems using life cycle impact assessment (LCIA). More specifically, the LCIA of Seawater Reverse Osmosis (SWRO) integrated with (i) an Electro-Dialysis (EDBMED) process and (ii) solar photovoltaics (PV) is investigated. Life cycle analysis was used to identify pertinent indicators of the LCIA and their implications in SWRO. The comparative analysis reveals that the advantage of SWRO as compared to other technologies such as MSF is energy efficiency, at estimated levels of 75.0%. The study concludes that despite the technological challenges associated with sustainable desalination and sustainable brine management, integrating renewable energy into seawater desalination can contribute to the sustainability improvements of seawater desalination systems. The findings of this paper provide an initial assessment of the ecological footprints of seawater desalination systems. [ABSTRACT FROM AUTHOR]

A comprehensive life cycle assessment was conducted on fermentation, pyrolysis, and gasification systems to compare their environmental performance of converting corn stover to biofuels. In addition, the normalization method was applied to compare different environmental impact categories. The differences and similarities in their environmental performance were explored, and the reasons for the differences were discussed. Comparatively, based on 1 GJ biofuel consumed, fermentation performs poorly on almost all environmental impact categories, while the equivalent CO2 emission of pyrolysis is the highest. Comparing with pyrolysis, the equivalent CO2 emission reductions can be more than 50% for the other systems. There are also similar regularities in the environmental performance of the three systems. The acidification potential is the most arresting impact category. Biofuel production and agriculture are identified as the processes that mainly affect the environment. Furthermore, sensitivity analysis on all 5 impact categories was conducted, demonstrating that biofuel yield is the most sensitive factor to nearly all impact categories. [ABSTRACT FROM AUTHOR]

Well-ordered aluminosilicates (MAs) were prepared by in-situ assembly of pre-crystallized units of zeolite Y precursors at a commercial scale, and applied in an industrial fluid catalytic cracking unit for the first time. Compared with incumbent equilibrium catalyst, the surface area of trial equilibrium catalysts (30% inventory ratio) increased from 110 m² g-1 to 120 m² g-1. Moreover, a significant increase of the mesoporous surface area of trial equilibrium catalysts (30% inventory ratio) from 33 m² g-1 to 40 m² g-1 (22% increase). Furthermore, the equilibrium catalyst that contain 80% LPC-65 yields significantly lower heavy oil (0.23%) and higher total liquids (0.53%) compared with LDO-70. The industrial results demonstrated excellent hydrothermal stability and superior catalytic cracking properties, showing the promising future in the industrial units. [ABSTRACT FROM AUTHOR]

Methanol-to-gasoline (MTG) and dimethyl ether-to-gasoline (DTG) fuels are rich in heavy aromatics such as 1,2,4,5-tetramethylbenzene, resulting in low volatilities due to a lack of light ends, increased emission tendencies and drivability problems due to crystallization. Approaches addressing these issues mainly focus on single aspects or are optimized for petroleum-based feedstocks. This research article introduces an upgrading strategy for MTG and DTG fuels through hydroprocessing (HP) heavy-ends and applying a sophisticated blending concept. Different product qualities were prepared by HP heavy gasoline (HG) and Fischer-Tropsch wax using commercially available Pt/HZSM-5 and Pt/SAPO-11 catalysts in a fixed-bed reactor. The products were used for blending experiments, focusing on gasoline volatility characteristics. Accordingly, methanol, ethanol, methyl tert-butyl ether (MTBE), and ethyl tert-butyl ether (ETBE) were evaluated in a second blending experiment. The results were finally considered for preparing blends meeting EN 228. HP of HG was found to improve the amount of light-ends and the vapor pressure of the DTG fuel with increasing reaction temperature without, however, satisfying EN 228. The front-end volatility was further improved by blending methanol due to the formation of near-azeotropic mixtures, while ethyl tert-butyl ether (ETBE) considerably supported the mid-range volatility. A final blend with an alcohol content of less than 3 vol.%, mostly meeting EN 228, could be provided, making it suitable even for older vehicles. [ABSTRACT FROM AUTHOR]

The global contamination of water resources by organic contaminants such as pharmaceuticals and pesticides is calling for advanced remediation techniques, yet conventional water treatments are incomplete or generate toxic byproducts such as chlorinated compounds. As a consequence, safer methods such as treatment with ferrate are needed. Here, we review the utilization of ferrate(VI), the tetraoxy anion FeO42−, with emphasis on synthesis and activation of ferrate. Ferrate synthesis is done by wet, thermal, and electrochemical processes. An increase in the oxidation capacity can be obtained by activation of ferrate(VI), which generates highly reactive high-valent iron species such as iron(V) and iron(IV) species. We present activation of ferrate(VI) by iron(III), copper(II), and colloidal Mn(IV), which are present in natural minerals. We compare various ferrate(VI)–metal ion systems to reveal the most effective systems to remove organic contaminants from contaminated water. [ABSTRACT FROM AUTHOR]

The synthesis of gasoline-range hydrocarbons by gas-phase dimethyl ether (DME) conversion was investigated on various ZSM-5 zeolites with different morphologies and Fe contents. The different morphologies of ZSM-5 significantly altered the distributions of the acidic sites, which showed different selectivities to gasoline-range hydrocarbons. Nanostructured ZSM-5 (N-ZSM-5) revealed the highest C5+ selectivity of 41.7% with an aromatics selectivity of 23.6% at ~100% DME conversion. The superior catalytic activity of N-ZSM-5 was attributed to the largest strong Brønsted acidic sites and smaller crystallite sizes, which were beneficial for the faster removal rate of heavy hydrocarbons due to its shorter diffusion pathlength compared to conventional ZSM-5 (C-ZSM-5). In addition, 10 wt% Fe-impregnated N-ZSM-5 revealed an enhanced C5+ selectivity of 60.6% with a smaller C1–C4 selectivity of 21.9%, which were attributed to the adjusted acidic sites by suppressing the cracking reactions of the surface intermediates, which are responsible for the selective formation of smaller light hydrocarbons. However, the excess amount of Fe on N-ZSM-5 showed a lower DME conversion of 83.5% with a lower C5+ selectivity of 38.5% due to the blockages of the active acidic sites. Nanostructured N-ZSM-5 possessing a larger amount of strong Brønsted acid sites with 10 wt% Fe modification clearly showed a higher formation rate of gasoline-range hydrocarbons due to an enhanced secondary oligomerization of surface intermediates to form heavier aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]

Complex pollutants are discharging and accumulating in rivers and oceans, requiring a coupled strategy to resolve pollutants efficiently. A novel method is proposed to treat multiple pollutants with C,N co-doped TiO2 hollow nanofibers coated stainless steel meshes which can realize efficient oil/water separation and visible light-drove dyes photodegradation. The poly(divinylbenzene-co-vinylbenzene chloride), P(DVB-co-VBC), nanofibers are generated by precipitate cationic polymerization on the mesh framework, following with quaternization by triethylamine for N doping. Then, TiO2 is coated on the polymeric nanofibers via in-situ sol–gel process of tetrabutyl titanate. The functional mesh coated with C,N co-doped TiO2 hollow nanofibers is obtained after calcination under nitrogen atmosphere. The resultant mesh demonstrates superhydrophilic/underwater superoleophobic property which is promising in oil/water separation. More importantly, the C,N co-doped TiO2 hollow nanofibers endow the mesh with high photodegradation ability to dyes under visible light. This work draws an affordable but high-performance multifunctional mesh for potential applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

Decarbonization of the aviation sector relies on deployment of sustainable aviation fuels (SAF) at commercial scale. Hydrothermal liquefaction (HTL) has been recognized as a promising technology to help supply the increasing projected SAF demand. High availability of agro-industrial residues, combined with a well-established biorefinery system, makes the sugarcane industry in Brazil a good option for HTL technology deployment. Moreover, challenges regarding the economic feasibility of SAF from HTL could be partially addressed by the RenovaBio policy, a market-driven incentive mechanism of carbon credits implemented in Brazil. This study investigated both the techno-economic and life cycle assessment of SAF production from sugarcane lignocellulosic residues, considering HTL integrated to a first-generation ethanol distillery and a HTL stand-alone facility. The evaluated scenarios showed great climate mitigation potential, reaching a reduction of up to 73–82% when compared to fossil jet fuel. The minimum fuel selling price of SAF at 15.4 USD/GJ indicated potential of economic competitiveness with fossil jet fuel in the best integrated scenario. The economic benefits obtained from carbon credits are not enough to enable feasibility of HTL in the stand-alone scenarios, even with carbon prices projected at 125 USD/tonne CO2-eq avoided. [ABSTRACT FROM AUTHOR]

Second-generation biomass (BM) can be produced in amounts that meet worldwide fuel demands. However, BM favors parallel and undesirable reactions in its transformation chain. We circumvent this problem by first modifying BM by ketalization, giving a user-friendly liquid we named BP (bio-petroleum). This study converted a representative compound of BP, DX (1,2:3,5-di-O-isopropylidene-α-D-xylofuranose), mixed with n-hexane by beta zeolites and catalysts containing beta zeolite. Beta zeolite showed low coke and high liquid product yields in converting this mixture (having 30 wt. % DX) into hydrocarbons in a fixed-bed reactor at 500 °C with a space velocity of 16 h−1 (0.3 catalyst/feed). Its performance was further improved by steam treatment (lowering the coke yield by lowering the acid site density) or incorporation into a catalyst (improving DX participation due to the active sites in the matrix). Further, by changing the conversion process from a fixed bed to a fluidized cracking unit, a much larger amount of the deactivated catalyst could be used (catalyst/feed = 3), remarkably reducing oxygenates and fully converting DX. Additionally, the green hydrocarbon efficiency (olefin, aromatics, furans, and cyclo-alkanes) of DX was approximately 77%. Hence, beta catalysts were shown to have a great potential to provide green fuels for future bio-refineries. [ABSTRACT FROM AUTHOR]

The elevated increase of CO2 emissions related to activities of the extractive industry is becoming a challenging issue gradually affecting climate change and global warming. In this frame, the effective utilisation of CO2 through the techniques of Carbon Capture and Storage (CCS) as well as Carbon Capture and Utilisation (CCU) can alleviate the greenhouse effect. Converting CO2 into a value-added chemical or liquid fuel (e.g., methanol, hydrocarbons, propylene, dimethyl ether, ethylene, etc.) is a promising approach in this regard. Methanol (MeOH) synthesis offers a key feedstock for industries, being both an industrial commodity for several chemical products and an efficient transportation fuel. This article presents a review of the CCS and CCU technologies for the production of MeOH in extractive industries. The CCS technologies investigated in this framework are the amine-based absorption and the WGS-enhanced CCS. The CCU technologies are CO2 hydrogenation and enhanced CO2 transformation by the Fischer-Tropsch reaction. Incorporating these systems for the processing of the flue-gases of the extractive industries significantly reduces the CO2 emissions, while creating new revenues by the production of valuable MeOH. [ABSTRACT FROM AUTHOR]

Different dynamics of climate change, population growth, and urbanisation challenge water service providers (WSPs) and those managing urban planning. The scientific community has been evidencing the concept of sustainable urban water management (SUWM) as a driver to foster the integration of the urban water cycle with its environmental, economic, and social sustainability dimensions. This article studies the approaches addressed by recent research on sustainable urban water management, focusing on the attention given by the scientific community to the way WSPs and city planners address the new challenges brought by climate change. A systematic review of existing literature shows how emergent challenges address the articulation between urban water cycle management and city planning. The results underline the need for the technical and economic evaluation of the overarching concept of SUWM systems, integrating values that go beyond financial issues; the need to address water scarcity not only from the supply side but also from the demand point of view; and the deepening of the relationship between new sources of water, such as the reuse, with the city planning in a context of climate change. Nevertheless, strategies for collaboration are still poorly addressed. The insights and gaps emerging from the analysis suggest new paths for research and practice in the field. [ABSTRACT FROM AUTHOR]

Myeloid-derived suppressor cells MDSCs are a heterogeneous population of cells that expand beyond their physiological regulation during pathologies such as cancer, inflammation, bacterial, and viral infections. Their key feature is their remarkable ability to suppress T cell and natural killer NK cell responses. Certain risk factors for severe COVID-19 disease, such as obesity and diabetes, are associated with oxidative stress. The resulting inflammation and oxidative stress can negatively impact the host. Similarly, cancer cells exhibit a sustained increase in intrinsic ROS generation that maintains the oncogenic phenotype and drives tumor progression. By disrupting endoplasmic reticulum calcium channels, intracellular ROS accumulation can disrupt protein folding and ultimately lead to proteostasis failure. In cancer and COVID-19, MDSCs consist of the same two subtypes (PMN-MSDC and M-MDSC). While the main role of polymorphonuclear MDSCs is to dampen the response of T cells and NK killer cells, they also produce reactive oxygen species ROS and reactive nitrogen species RNS. We here review the origin of MDSCs, their expansion mechanisms, and their suppressive functions in the context of cancer and COVID-19 associated with the presence of superoxide anion •O2− and reactive oxygen species ROS. [ABSTRACT FROM AUTHOR]

Catalytic fast pyrolysis of sunflower seed shells was performed using a two‐stage fixed bed reactor to produce partially deoxygenated bio‐oils. Ketonization and aldol condensation reactions were performed in a dual bed reactor using a CeO2 catalyst followed by a bifunctional Cu/Ni/ZrO2 catalyst. An ethanol‐saturated N2 stream was supplied to increase the H/C ratio of the pyrolysis intermediates. The oxygen content decreased from 23 to 13 wt % over the CeO2 fixed‐bed due to the almost complete conversion of methoxy phenols and the formation of ketones and alkyl‐substituted phenols. The Cu/Ni/ZrO2 catalyst in the presence of ethanol vapor increased the fraction of alkanes in the condensed product and favored the formation of larger ketones and higher molecular weight species. Miscibility tests showed that the partially upgraded bio‐oil could be homogeneously blended with fossil fuel oil in a 1:4 mass ratio. The oily fraction of the non‐catalytic pyrolysis bioliquid (oxygen content up to 23 wt %) was also partially miscible with the petroleum‐derived fuel. [ABSTRACT FROM AUTHOR]

In the future, synthetic fuels could replace fossil fuels to minimize the CO2 emissions of combustion engines. Dimethyl carbonate (DMC) and methyl formate (MeFo) represent not only possible synthetic fuels but, due to their oxygen content, also have properties to reduce the pollutant emissions. For a good combustion process, the spray targeting and evaporation properties are important. Due to the less known injection behavior of DMC and MeFo, the spray characteristics were examined in a pressure chamber. The penetration depth, projected spray area, and spray angle were investigated at injection pressures of 100 and 200 bar, chamber pressures of 1 and 2.5 bar, and a temperature variation of up to 90°C for two different injector spray angles and flow rates in comparison with gasoline E5. The spray was recorded with a high-speed camera in a constant-volume chamber with a N2 environment. Both fuels showed a faster evaporation than E5 even with a higher injection mass due to their lower LHV. MeFo showed extreme spray collapse and flash boiling effects, which lead to even faster evaporation rates and higher penetration velocities. [ABSTRACT FROM AUTHOR]

The scarcity of energy and water resources and rising temperatures due to climate change has set the focus on improving the energy efficiency of power plant thermodynamic cycles to adapt to higher heat sink temperatures and use fewer resources for energy production. In this work, a review of power production thermodynamic cycles is presented: from Brayton to Rankine and combined cycles, alongside particular cycles such as Organic Rankine Cycles, Kalina, Goswami or the more recently developed Hygroscopic Cycle. The efficiency of these cycles and their possible improvements are considered, as well as their environmental impact. Costs associated with existing power plants found in the literature have also been included in the study. The main existing facilities for each cycle type are assessed, and the most sustainable options in terms of resource consumption (fuel, water, etc.) and future perspectives to ensure both their energy efficiency and sustainability are identified. [ABSTRACT FROM AUTHOR]

A ruthenium catalyst based on hexagonal mesoporous silica modified with aluminum (Al-HMS structural type) of a Si/Al ratio equal to 10 was studied in the hydrodeoxygenation reaction of bio-oil components containing a guaiacol fragment. The catalyst was tested in the hydrodeoxygenation of guaiacol, methoxyguaiacol, formylguaiacol, and propylguaiacol in the presence of water at a hydrogen pressure of 6.0 MPa and a temperature of 250°C. The effect of the substrate structure on the conversion and selectivity of hydrotransformation towards fully hydrogenated and deoxygenated products is shown. The effect of temperature in the range of 210–290°C on the conversion and distribution of guaiacol hydrodeoxygenation products at various hydrogen pressures (2.5 and 6.0 MPa) is demonstrated. Experiments were carried out on the hydrodeoxygenation of guaiacol in a mixture with water, n-dodecane, and methanol at a hydrogen pressure of 6.0 MPa and a temperature of 250°C. The effect of the model mixture composition on the conversion and distribution of guaiacol hydrodeoxygenation products is shown. [ABSTRACT FROM AUTHOR]

We have been developing a three‐step conversion of biomass‐derived syngas to methanol to dimethyl‐ether (DME) to non‐aromatic hydrocarbons for use as high‐octane gasoline and sustainable aviation fuel. This process produces branched alkanes from DME using a Cu/BEA catalyst and is a promising alternative to other syngas conversion processes such as Fischer–Tropsch to linear alkanes and traditional ZSM‐5 catalyzed methanol to aromatic gasoline. In this short article we describe some advances in our understanding related to separation and purification via the use of more detailed experimental speciation in an updated process model involving multiple‐phase equilibrium‐based separation steps. The primary modeled reactor outlet constituents (and wt%) are: C3 and lighter hydrocarbon gases (11.1%), C4s (54.5%), H2 (1.2%), CO2 (2.9%), water (5.0%), unreacted DME (16.5%), methanol (2.3%) and C5+ hydrocarbons (6.4%). Dimethyl‐ether (the primary reactant) and H2 recycling and reuse are important for the overall process efficiency, and the recycling of C4s is important to increase the C5+ yield via reactivation and homologation. Thus H2, C4s and DME are targeted for recycling, while methanol and water need to be removed from the product to conform with fuel specifications. Model predictions from Aspen Plus using the NRTL‐RK property method indicate a fuel composition with a C5+ content of 97.1 wt%, with the minor constituents 2.4 wt% C4s, 0.3 wt% methanol, 0.1 wt% DME, 0.03 wt% water and 0.01 wt% C3s. These ranges of minor components conform with fuel quality requirements, and the modeled product is amenable for unconstrained blending to boost gasoline octane ratings. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The production of bio‐ethylene is a promising way to replace fossil‐based ethylene production, reducing greenhouse gas emissions and working towards China's carbon neutrality goals. This study elaborates on five bio‐ethylene technological pathways: first‐ and second‐generation bioethanol dehydration, direct and indirect thermochemical synthesis, and methanol‐to‐olefins (MTO). It retrieves information about them from commercial patents and the scientific literature, and comprehensively assesses their potential for application in large‐scale ethylene production in China. The techno‐economic feasibility of these five technological pathways is discussed in terms of feedstock availability, investment level, technological development level, and political issues such as the carbon neutrality goal to which China's government is committed. Overall, two pathways (indirect thermochemical synthesis and MTO) exhibited competitive minimum ethylene selling prices at 5243 yuan/t (822 USD t–1) and 6767 yuan/t (1061 USD t–1), respectively, of which both are lower than the average ethylene market price of 7000 yuan/t (1098 USD t–1). In comparison with the conventional fossil‐derived ethylene, bio‐ethylene could decrease carbon emission by 3.2%–15.1% under a scenario of 20% bio‐ethylene substitution in 2019, showing promising potential for decarbonizing the ethylene industry and contributing to the achievement of China's carbon neutrality goals. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio‐based products. Short rotation coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, easy to manage cultivation system with vegetative propagation of plant material and multiple harvests from the same plantation. The aim of the present paper is to provide an overview of the main challenges and key issues in willow genetic improvement toward sustainable biofuel value chains. Primarily based on results from the research project "Optimized Utilization of Salix" (OPTUS), the influence of Salix wood quality on the potential for biofuel use is discussed, followed by issues related to the conversion of Salix biomass into liquid and gaseous transportation fuels. Thereafter, the studies address genotypic influence on soil carbon sequestration in Salix plantations, as well as on soil carbon dynamics and climate change impacts. Finally, the opportunities for plant breeding are discussed using willow as a resource for sustainable biofuel production. Substantial phenotypic and genotypic variation was reported for different wood quality traits important in biological (i.e., enzymatic and anaerobic) and thermochemical conversion processes, which is a prerequisite for plant breeding. Furthermore, different Salix genotypes can affect soil carbon sequestration variably, and life cycle assessment illustrates that these differences can result in different climate mitigation potential depending on genotype. Thus, the potential of Salix plantations for sustainable biomass production and its conversion into biofuels is shown. Large genetic variation in various wood and biomass traits, important for different conversion processes and carbon sequestration, provides opportunities to enhance the sustainability of the production system via plant breeding. This includes new breeding targets in addition to traditional targets for high yield to improve biomass quality and carbon sequestration potential. [ABSTRACT FROM AUTHOR]

In order to increase the typically low equilibrium CO2 conversion to methanol using commercially proven technology, the addition of two intermediate condensation units between reaction steps is evaluated in this work. Detailed process simulations with heat integration and techno-economic analyses of methanol synthesis from green H2 and captured CO2 are presented here, comparing the proposed process with condensation steps with the conventional approach. In the new process, a CO2 single-pass conversion of 53.9% was achieved, which is significantly higher than the conversion of the conventional process (28.5%) and its equilibrium conversion (30.4%). Consequently, the total recycle stream flow was halved, which reduced reactant losses in the purge stream and the compression work of the recycle streams, lowering operating costs by 4.8% (61.2 M€·a−1). In spite of the additional number of heat exchangers and flash drums related to the intermediate condensation units, the fixed investment costs of the improved process decreased by 22.7% (94.5 M€). This was a consequence of the increased reaction rates and lower recycle flows, reducing the required size of the main equipment. Therefore, intermediate condensation steps are beneficial for methanol synthesis from H2/CO2, significantly boosting CO2 single-pass conversion, which consequently reduces both the investment and operating costs. [ABSTRACT FROM AUTHOR]

We propose a methodology to add new technologies into Environmentally Extended Input–Output (EEIO) models based on a Supply and Use framework. The methodology provides for adding new industries (new technologies) and a new commodity under the assumption that the new commodity will partially substitute for a functionally-similar existing commodity of the baseline economy. The level of substitution is controlled by a percentage (%) as a variable of the model. In the Use table, a percentage of the current use of the existing commodity is transferred to the new commodity. The Supply or Make table is modified assuming that the new industries are the only ones producing the new commodity. We illustrate the method for the USEEIO model, for the addition of second generation biofuels, including naphtha, jet fuel and diesel fuel. The new industries' inputs, outputs and value-added components needed to produce the new commodity are drawn from process-based life cycle inventories (LCIs). Process-based LCI inputs and outputs per physical functional unit are transformed to prices and assigned to commodities and environmental flow categories for the EEIO model. This methodology is designed to evaluate the environmental impacts of substituting products in the current US economy with bio-versions, produced by new technologies, that are intended to reduce negative environmental impacts. However, it can be applied for any new commodity for which the substitution assumption is reasonable. [ABSTRACT FROM AUTHOR]

Anaerobic digestion of lignocellulosic biomass faces changes such as biomass floating and effluent discharge. To overcome these challenges, a unique removable cartridge anaerobic digester was built and tested using corn stover as the feedstock. Three operating methods differing in the number of cartridges and days of rotation were tested. The first method used three cartridges, with each cartridge being rotated every 7 days. The second and third methods employed four cartridges, with cartridges being rotated every 7 and 9–10 days, respectively. The retention time for methods 1, 2, and 3 was 21, 28, and 38 days, respectively. After observation spanning 1 year, it was found that the cartridge digester was capable of generating a stable amount of biogas for energy without biomass floating or effluent discharging issues. The average daily methane yield from each method was 7.57, 7.11, and 6.82 L/day/kg-VS, and the cumulative methane yield was 158.95, 199.04, and 259.00 L/kg-VS, respectively. Ammonium nitrogen and pH values were in normal ranges throughout the experiment. This study provided new knowledge in operating and optimizing this cartridge digester, which may be broadly used for the anaerobic digestion of lignocellulosic biomass in the near future. [ABSTRACT FROM AUTHOR]

In this paper, we describe multiple scenarios to assess the techno‐economic results of producing hydrocarbon fuels from corn stover‐derived ethanol and the impact of co‐producing higher‐value, ethanol‐derived n‐butanol and 1,3‐butadiene to improve economic feasibility. In our baseline process, the stover‐derived lignin is burned for its energy content to raise process steam and electricity. We evaluated an alternative approach based on the same stover‐to‐ethanol process, but instead of burning residual lignin to produce heat and electricity, it was fed to a hydrothermal liquefaction process and converted into hydrocarbon fuel, while the ethanol from fermentation is used to make only butanol or butadiene. Our results indicate that the hydrothermal liquefaction pathways have significant cost advantages over the pathways that burn the lignin. For comparison purposes, two more scenarios were evaluated based on the assumption that ethanol was purchased at market prices and converted to butanol or butadiene exclusively. This comparison evaluates the economics for making higher‐valued chemicals which, in the absence of incentives, would be the most profitable approaches in our study. The results for these evaluations indicated that the ethanol‐to‐butanol economics were generally favorable and achieved or exceeded the 10% internal rate of return target. The butadiene process had less favorable economic performance in some years when the market price for butadiene was less than the selling price needed to achieve the internal rate of return. Economic incentives for low‐carbon chemicals and fuels were not considered in our analysis. © 2022 Battelle Memorial Institute. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Biofuel consists of non-fossil fuel derived from the organic biomass of renewable resources, including plants, animals, microorganisms, and waste. Energy derived from biofuel is known as bioenergy. The reserve of fossil fuels is now limited and continuing to decrease, while at the same time demand for energy is increasing. In order to overcome this scarcity, it is vital for human beings to transfer their dependency on fossil fuels to alternative types of fuel, including biofuels, which are effective methods of fulfilling present and future demands. The current review therefore focusses on second-generation lignocellulosic biofuels obtained from non-edible plant biomass (i.e., cellulose, lignin, hemi-celluloses, non-food material) in a more sustainable manner. The conversion of lignocellulosic feedstock is an important step during biofuel production. It is, however, important to note that, as a result of various technical restrictions, biofuel production is not presently cost efficient, thus leading to the need for improvement in the methods employed. There remain a number of challenges for the process of biofuel production, including cost effectiveness and the limitations of various technologies employed. This leads to a vital need for ongoing and enhanced research and development, to ensure market level availability of lignocellulosic biofuel. [ABSTRACT FROM AUTHOR]

Co‐processing biogenic feedstocks in oil refineries will reduce the greenhouse gas emissions normally associated with fossil‐derived transportation fuels. The fluid catalytic cracker (FCC) within a refinery is a robust processing unit and will probably be a preferred insertion point if biocrudes, produced by the liquefaction of biomass, are co‐processed within a refinery. Fluid catalytic cracking results in a wide range of intermediate products which can be upgraded to gasoline, diesel, heavy fuel oil and liquified petroleum gas blendstocks. Coke is also produced and provides heating for feedstocks, the endothermic catalytic cracking reactions and the regeneration of the FCC catalyst. However, coke combustion also generates carbon dioxide and is a significant source of refinery greenhouse gas emissions. As detailed here, the continuous nature of the process makes the physical evaluation of any biogenic coke fraction, via methods such as C14 isotope analysis, quite challenging. However, quantifying the stack gases provides one way of assessing the renewable content of the carbon dioxide derived from coke combustion. The hourly data from 1 year of commercial operation was assessed using linear and Bayesian ridge regression to quantify the burning coefficient of the coke when co‐processing lipids at the FCC. When a bootstrap method was used to reduce the uncertainties of the coefficients, this allowed us to quantify the renewable (green) fraction of the coke component, indicating the reduction in carbon dioxide emissions when commercially co‐processing biogenic feedstocks. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Feedstock attributes of lignocellulosic biomass, such as particle size, compositional makeup, and moisture content, can vary substantially even within pre‐processed materials and have a significant effect on conversion in fast pyrolysis‐based processes. However, the economic impacts of these attributes are not well understood. To address this, biomass deconstruction phenomena captured with a versatile particle‐scale simulation were linked to techno‐economic impacts via reduced‐order models. Parametric analysis of the particle‐scale model, which was validated using literature data, was used in combination with multiple linear regression models to develop correlations between feedstock attributes and yields of pyrolysis oil, gas, and char. Yields were then correlated with the minimum fuel selling price (MFSP) using a techno‐economic model, bridging the gap between physics‐based biomass conversion simulations and predictions of MFSP for a catalytic fast‐pyrolysis process. Empirical correlations derived from the literature regarding the impact of mineral matter (ash) on oil yield were also considered. The model correlations deployed in the integrated framework capture the impacts of variation in feedstock attributes on the MFSP. Variations in ash were shown to have the biggest impact, varying MFSP by −13%/+22% due to catalytic effects and lower relative amounts of convertible lignocellulosic material. It was also found that, if ash can be controlled to low levels, the increased extractives in forest residues can help compensate for some yield losses associated with increased ash. Other inputs considered (particle size, moisture content, and reactor temperature) had relatively negligible effects on process economics within the ranges analyzed considering particle‐scale effects alone. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Background: Microalgae possess numerous advantages for use as a feedstock in producing renewable fuels and products, with techno-economic analysis (TEA) frequently used to highlight the economic potential and technical challenges of utilizing this biomass in a biorefinery context. However, many historical TEA studies have focused on the conversion of biomass with elevated levels of carbohydrates and lipids and lower levels of protein, incurring substantial burdens on the ability to achieve high cultivation productivity rates relative to nutrient-replete, high-protein biomass. Given a strong dependence of algal biomass production costs on cultivation productivity, further TEA assessment is needed to understand the economic potential for utilizing potentially lower-cost but lower-quality, high-protein microalgae for biorefinery conversion. Results: In this work, we conduct rigorous TEA modeling to assess the economic viability of two conceptual technology pathways for processing proteinaceous algae into a suite of fuels and products. One approach, termed mild oxidative treatment and upgrading (MOTU), makes use of a series of thermo-catalytic operations to upgrade solubilized proteins and carbohydrates to hydrocarbon fuels, while another alternative focuses on the biological conversion of those substrates to oxygenated fuels in the form of mixed alcohols (MA). Both pathways rely on the production of polyurethanes from unsaturated fatty acids and valorization of unconverted solids for use as a material for synthesizing bioplastics. The assessment found similar, albeit slightly higher fuel yields and lower costs for the MA pathway, translating to a residual solids selling price of $899/ton for MA versus $1033/ton for MOTU as would be required to support a $2.50/gallon gasoline equivalent (GGE) fuel selling price. A variation of the MA pathway including subsequent upgrading of the mixed alcohols to hydrocarbon fuels (MAU) reflected a required solids selling price of $975/ton. Conclusion: The slight advantages observed for the MA pathway are partially attributed to a boundary that stops at oxygenated fuels versus fungible drop-in hydrocarbon fuels through a more complex MOTU configuration, with more comparable results obtained for the MAU scenario. In either case, it was shown that an integrated algal biorefinery can be economical through optimal strategies to utilize and valorize all fractions of the biomass. [ABSTRACT FROM AUTHOR]

The global demand for acrylic acid (AA) is increasing due to its wide range of applications. Due to this growing demand, alternative AA production strategies must be explored to avoid the exacerbation of prevailing climate and global warming issues since current AA production strategies involve fossil resources. Investigations regarding alternative strategies for AA production therefore constitute an important research interest. The present study assesses waste apple pomace (WAP) as a feedstock for sustainable AA production. To undertake this assessment, process models based on two production pathways were designed, modelled and simulated in ASPEN plus® software. The two competing production pathways investigated included a process incorporating WAP conversion to lactic acid (LA) prior to LA dehydration to generate AA (denoted as the fermentation–dehydration, i.e., FD, pathway) and another process involving WAP conversion to propylene prior to propylene oxidation to generate AA (denoted as the thermochemical–fermentation–oxidation, i.e., TFO, pathway). Economic performance and potential environmental impact of the FD and TFO pathways were assessed using the metrics of minimum selling price (MSP) and potential environmental impacts per h (PEI/h). The study showed that the FD pathway presented an improved economic performance (MSP of AA: USD 1.17 per kg) compared to the economic performance (MSP of AA: USD 1.56 per kg) of the TFO pathway. Crucially, the TFO process was determined to present an improved environmental performance (2.07 kPEI/h) compared to the environmental performance of the FD process (8.72 kPEI/h). These observations suggested that the selection of the preferred AA production pathway or process will require a tradeoff between economic and environmental performance measures via the integration of a multicriteria decision assessment in future work. [ABSTRACT FROM AUTHOR]

Feedstock cost and cost variability is expected to increase with the number of biorefineries. To quantify this effect, this spatial‐economic analysis simulates feedstock cost and cost variability of an industry based on corn stover as a function of the number of biorefineries. Results are reported for nine scenarios (a base case and sensitivity analysis of four variables – harvest efficiency, sustainability constraints, opportunity cost, and corn grain yield) under deterministic and stochastic simulations, assuming biorefineries using 658 000 Mg (725 000 tons) year−1 of corn stover in 2019. The resulting supply curves are highly elastic (i.e. little change in cost) for the first 50 of the 121 biorefineries, with price increases in subsequent biorefineries depending on scenario. In the base‐case deterministic scenario, weighted‐average stover costs are $66 Mg−1 ($60 ton−1), $69 Mg−1 ($62 ton−1), and $156 Mg−1 ($142 ton−1), at the first, 60th, and 121st biorefineries, respectively. The stochastic simulations, subject to observed 30‐year corn yield variability, follow a similar pattern, with price distributions that vary by scenario. The base‐case stochastic simulations illustrate minimal cost variability for the first 60 biorefineries, but rapid increases in cost variability in the second half of potential biorefineries, with similar patterns observed in the other scenarios. Of the four variables explored, price was most sensitive to harvest efficiency, followed by sustainability constraints, corn yield, and opportunity cost. Results suggest that, under conventional logistics, about half of the US corn stover resource is reliably available with minimum cost increase and variability. Interactive visualization is available at https://doi.org/10.11578/1828779. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Global climate change will make it necessary to transform transportation and mobility away from what we know now towards a sustainable, flexible, and dynamic sector. A severe reduction of fossil-based CO2 emissions in all energy-consuming sectors will be necessary to keep global warming below 2 °C above preindustrial levels. Thus, long-distance transportation will have to increase the share of renewable fuel consumed until alternative powertrains are ready to step in. Additionally, it is predicted that the share of renewables in the power generation sector grows worldwide. Thus, the need to store the excess electricity produced by fluctuating renewable sources is going to grow alike. The "Winddiesel" technology enables the integrative use of excess electricity combined with biomass-based fuel production. Surplus electricity can be converted to H2 via electrolysis in a first step. The fluctuating H2 source is combined with biomass-derived CO-rich syngas from gasification of lignocellulosic feedstock. Fischer-Tropsch synthesis converts the syngas to renewable hydrocarbons. This research article summarizes the experiments performed and presents new insights regarding the effects of load changes on the Fischer-Tropsch synthesis. Long-term campaigns were carried out, and performance-indicating parameters such as per-pass CO conversion, product distribution, and productivity were evaluated. The experiments showed that integrating renewable H2 into a biomass-to-liquid Fischer-Tropsch concept could increase the productivity while product distribution remains almost the same. Furthermore, the economic assessment performed indicates good preconditions towards commercialization of the proposed system. [ABSTRACT FROM AUTHOR]

Novolac resins are produced by reacting phenol and formaldehyde, which are both conventionally obtained from petroleum refining. However, phenolic compounds present in bio‐oil obtained via fast pyrolysis of lignocellulosic biomass can be used to partially substitute petroleum‐derived phenol. Thus, the objective of this study was to analyze the techno‐economic feasibility of producing novolac resin by partially substituting petroleum‐derived phenol with biomass‐based phenol in the U.S. The analysis was done at two different annual novolac resin production capacities of 25, 000 and 100, 000 t, respectively, representing the existing small‐ and large‐scale resin production facilities in the U.S. Mass balance and energy analyses of the system were performed to estimate resources (equipment, raw materials, consumables, utilities, and labor) requirements, capital and operating costs, and the financial parameters, including the minimum selling price (MSP). The MSPs for biomass‐based novolac resin for 25, 000 and 100, 000 t capacities were estimated to be $1,585 t–1 and $1,250/t–1, respectively, which falls below its current market price range ($1,700‐3,200 t–1). The bio‐oil to phenol substitution ratio, phenol content in bio‐oil, phenol cost, plant size, biomass feedstock cost, and resin synthesis residence time were the most sensitive parameters affecting the production cost and MSP of novolac resin. The production of biobased novolac resin has the potential to be economically feasible at the current state of technology, and could be an important outlet for diversifying the use of bio‐oil. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Summary: In this study, a multiobjective optimization problem (MOOP) with two objective functions (maximization of di‐methyl‐ether (DME) production rate and minimization of carbon dioxide release) was applied to the direct synthesis of DME from a natural gas‐derived synthesis gas (syngas). Twelve degrees of freedom were considered. The MOOP results suggest that the process with a maximum DME production rate of 1686 kmol/hr releases 4788 kmol/hr CO2 while the CO2 release of the process with DME production rate of 1282 kmol/hr is 1761 kmol/hr. The higher the DME production rate, the lower net CO2 emission to the air, natural gas consumption, and energy consumption per kg of the DME produced. In addition, the process with a higher DME production rate has a higher carbon efficiency and power production from the produced steam. The annual profit criteria of the overall process were used as a posterior preference index to select the best point from the resultant multiobjective optimization Pareto front. It was shown that the plant with the topmost DME production rate has the utmost annual profit compared to other Pareto optimum points. Lastly, the effect of degrees of freedom on the maximum DME production rate is discussed. [ABSTRACT FROM AUTHOR]

A new forest biorefining model is emerging in which high‐value materials would be produced alongside a cellulosic sugar by‐product in facilities scaled to match fiber availability in northern forests. As these emerging biorefining technologies are being developed by private entities, the economics associated with them are little known. The goal of this study is to use publicly available information to carry out an initial techno‐economic assessment for two emerging biorefining technologies: one that produces sugar and hydrolysis lignin (H‐lignin) from thermomechanical pulping (TMP) and another that produces sugar, lignosulfonate, and nanocellulose. The break‐even price for H‐lignin and nanocellulose is estimated for the respective technology and a credit is applied for cellulosic sugar and other co‐product sales based on current market value. It was found that the minimum product selling price (MPSP) for H‐lignin was within the range of high purity lignin but not enough is known about the properties of H‐lignin to determine if this is a reasonable value for prospective end uses. The estimated MPSP of nanocellulose was found to be considerably lower than for more conventional nanocellulose‐producing methods that use Kraft or dissolving pulp as a starting point. The nanocellulose produced through the second process modeled has different properties than conventional nanocellulose, which need to be further explored. Having a sense of the cost to produce these novel materials will help to direct research on viable end uses. The methodology presented, using only publicly available information, can also be replicated for other emerging technologies. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Replacing fossil jet fuel with biojet fuel is an important step towards reducing greenhouse gas (GHG) emissions from aviation. To this end, Sweden has adopted a GHG mandate on jet fuel, complementing those on petrol and diesel. The GHG mandate on jet fuel requires a gradual reduction in the fuel's GHG emissions to up to 27% by 2030. This paper estimates the potential production of biojet fuel in Sweden for six integrated production pathways and analyzes what they entail with regard to net biomass input and the amount of hydrogen required for upgrading to fuel quality. Integrated production of biofuel intermediates from forestry residues and by-products at combined heat and power plants as well as at the forest industry, followed by upgrading to biojet fuel and other transportation fuels at a petroleum refinery, was assumed in all the pathways. The potential output of bio-based transportation fuels was estimated to 90 PJ/y, including 22 PJ/y of biojet fuel. The results indicate that it will be possible to meet the Swedish GHG mandate for jet fuel for 2030, although it will be difficult to simultaneously achieve the GHG mandates for road transportation fuels. This highlights the importance of pursuing complementary strategies for bio-based fuels. [ABSTRACT FROM AUTHOR]