Fossil Feedstocks Research Articles

Sustainable nitrogen photofixation: Considerations on the state of the art of non critical carbon materials

AbstractThe achievement of a carbon‐neutral energy economy is nowadays mandatory to face global warming and the current energy crisis. To mitigate the present and future environmental issues, replacing fossil feedstocks with renewable sources is of primary importance, aiming to meet future generations' demands for energy and commodities. In light of this, the revamp of the ammonia synthesis, which today consumes almost 2% of the energy globally produced, gained increasing interest. The ammonia generation by reacting air and water and using sunlight as an inexhaustible source of energy is the closest approach to the ideal situation for zero‐carbon energy and chemical production. To promote solar‐to‐ammonia production, the photocatalyst plays a crucial role. However, for large‐scale implementation and long‐term utilization, the selection of noncritical raw materials in catalyst preparation is central aiming at resource security. In this context, herein are reviewed different strategies developed to improve the photocatalytic performances of carbon‐based materials. The introduction of vacancies and surface doping are discussed as valuable approaches to enhance the photocatalytic activity in the nitrogen fixation reactions, as well as the construction of heterojunctions to finely tune the electronic properties of carbon‐based materials.

Optimization of UV-Curable Polyurethane Acrylate Coatings with Hexagonal Boron Nitride (hBN) for Improved Mechanical and Adhesive Properties.

Polymer coatings are widely used in industries for protection, decoration, and specific applications, typically including volatile organic compounds (VOCs) to achieve low viscosity. The growing environmental concerns and the anticipated limits on fossil feedstock have driven the coating industry towards eco-friendly alternatives, with UV-curing technology emerging as a promising solution due to its energy efficiency, low-temperature operation, reduced VOC emissions, and high curing speed. Polyurethane acrylates (PUAs) are critical in UV-curable formulations, offering excellent flexibility, impact strength, optical, and adhesion properties. However, UV-cured PUA coatings face limitations in thermal stability and tensile strength, which can be addressed by incorporating fillers. This study investigates the effects of multi-functionalized hexagonal boron nitride (hBN) nanoparticles on the mechanical, thermal, optical, and adhesion properties of UV-cured PUA films and coatings for pre-coated metals. The results demonstrated that incorporating hBN nanoparticles enhanced the mechanical and thermal properties of the nanocomposite films, with optimal performance observed at 0.5% hBN loading. Despite the improved properties, the FTIR spectra indicated that the low concentration of hBN did not produce significant changes, potentially due to the overshadowing signals from the difunctional polyurethane acrylate.

Prediction of hydrogen consumption scale and hydrogen price based on LEAP model and two-factor learning curve

Under the dual-carbon target, hydrogen energy, as a zero-carbon secondary energy source, has great scope for replacing fossil feedstocks in the fields of energy, transportation and industry. However, the current research on the competitiveness of hydrogen energy in various fields is not sufficiently addressed. In this paper, we use the LEAP model to predict the future scale of hydrogen use and the two-factor learning curve to predict the trend of hydrogen price change from 2025 to 2050, using Qinghai Province as the research background. At the same time, considering the carbon emission reduction benefits and raw material costs, the competitiveness of hydrogen energy in energy, transportation, industry and other fields in the future is compared. The results show that: 1) The hydrogen load scale in Qinghai Province will grow fast from 2025 to 2030. From 2030 to 2040, it slows under the steady and basic scenarios but remains high under the accelerated one. By 2040, the consumption scales are 1.057 million, 649,000 and 442,000 tons respectively. 2) The price of hydrogen energy will drop rapidly from the current 28 CNY/kg to about 20 CNY/kg in the next 5 years. By 2040, the price of hydrogen energy will be reduced to about 17 CNY/kg. 3) In terms of hydrogen energy competitiveness, when carbon emissions are not taken into account, hydrogen energy is currently competitive in the transportation field. During 2032–2038, it will be competitive in the field of methanol synthesis. By 2040, hydrogen energy will not be competitive in the fields of ammonia synthesis and power/heating. When considering carbon emissions, the competitiveness of hydrogen energy in the transportation field will become greater. The competitive year in the field of methanol synthesis will be 1–2 years ahead. By 2040, it will not be competitive in the field of synthetic ammonia and power/heating, but the gap will be significantly reduced due to the consideration of carbon emissions.

Impact of Hole Scavengers on Efficient Photocatalytic Hydrogen Production

AbstractHydrogen is one of the most promising alternative energy resources to replace fossil feedstocks, with so‐called “green” hydrogen, derived by water splitting (WS) using renewable electricity or sunlight, the most sustainable. Photocatalytic hydrogen production, in which sunlight is the sole energy input, has been extensively studied, and requires the creation of photogenerated excitons (through irradiation of semiconductors) and their transport to aqueous media. Chemical scavengers, notably electron donating molecules, are widely used to quench photogenerated holes and thereby suppress exciton recombination which otherwise limits the hydrogen yield. Despite their prevalence, the role and significance of such scavengers (also termed sacrificial agents) in photocatalytic WS remains poorly understood, hindering their rational selection. This review focuses on the importance of electron donors in photocatalytic WS, and their participation in the reaction mechanism.

Accelerated Development and Optimization of Adiponitrile Production via Kolbe Electrolysis of Biomass-Derived Precursors

Environmental and societal pressures are demanding a transition from fossil-based resources to renewable and sustainable feedstocks for the production of materials. In this context, biomass streams emerge as scalable candidates for creating sustainable chemicals. Electrocatalytic transformation of biomass can facilitate the production of chemicals under mild conditions and can be easily integrated with renewable energy sources. These transformations could lead to the production of sustainable monomers and polymers from biomass, significantly enhancing the sustainability of plastics production. Amongst a large number of plastics manufactured by the chemical industry, Nylon 6,6 is one of the most important fossil-derived polymers for the production of high-performance textiles and structural materials. Central to Nylon 6,6 production is adiponitrile (ADN), predominantly synthesized via energy-intensive thermochemical processes. An alternative route, electrochemical hydrodimerization of acrylonitrile (AN), although successful, still depends on fossil feedstocks. A promising sustainable source for ADN is renewable glutamic acid, derived from hydrolysis of waste proteins.1,2 This process involves transforming glutamic acid to 3-cyanopropanoic acid (CPA) and then to ADN through Kolbe electrolysis, a reaction with a historical background and multiple pathways. Our study utilizes an electrochemical reaction engineering approach to examine the Kolbe electrolysis of CPA to ADN and AN, focusing on a hierarchical research methodology. This approach allowed us to simultaneously accelerate the exploration of numerous reaction parameters while also conducting detailed studies under optimal conditions. This method has enabled us to gain deeper insights into the factors controlling reaction selectivity. We discovered that platinum electrodes favor ADN formation, with selectivity increasing at higher current densities. Optimal CPA concentrations, the presence of larger alkali cations, solvent composition, and controlled pH levels significantly influence ADN production, reducing side reactions such as the oxygen evolution reaction (OER). When using graphite electrodes, an increase in AN production was observed, with the solvent composition playing a crucial role in determining the rate of ADN formation. Our investigation has led to a deeper understanding of the electrochemical conversion of CPA to ADN, revealing key parameters that influence reaction selectivity and rate. The insights obtained from this study are not only pivotal for the specific case of ADN production but also have broader implications for a range of electrochemical decarboxylation reactions. The hierarchical research approach employed here demonstrates its potential for speeding the development of sustainable electrochemical processes. Our insights and methodology used for the electrosynthesis of ADN from biomass-derived feedstocks can be deployed to the deployed to the development of other biomass transformations advancing our ability to produce essential chemicals sustainably.

Fossil materials demand within deep decarbonization scenarios: A feasibility assessment

Integrated Assessment Models (IAMs) are cornerstone tools in guiding decarbonization policies. However, the petrochemical sector, which is crucial to the future of oil and gas due to its non-energy fossil feedstock demands, has been overlooked in IAMs. This study aims to evaluate the implications of this under-representation on decarbonization strategies. We assessed the Illustrative Mitigation Pathways from the Intergovernmental Panel on Climate Change in its Sixth Assessment Report. Our analysis indicates that, without stringent material policies, the feedstock demand can reach unattainable levels from 2050 onwards. This is evidenced by the required disruptive yields of primary oil in feedstocks, which exceed 80 % in some cases. The findings highlight the necessity for improved modelling of the petrochemical sector within IAMs.

Highly stable mesoporous-controlled corncob biochar confined paraffinic material with exceptional latent heat retention performance

Bio-based composites fabricated from bio-sourced waste feedstocks have attracted increasing interest and have shown potential applications in sustainable energy infrastructure development. Thermal management using phase-change materials (PCMs) has appeared as an innovative approach for energy storage and cooling, where pure PCMs that lack thermal stability are encapsulated in solid matrices to ensure the charge/discharge of the latent heat of the composite. However, their energy storage density, thermal stability, and durability are reduced after multiple thermal cycles, besides the complicated and expensive nonrenewable fossil feedstock utilization. Biochar, mostly used for soil remediation, can be redirected and repurposed for the encapsulation of PCMs in renewable energy storage infrastructures. In this study, a “greener” biochar-based composite was fabricated from agricultural corncob-derived biochar (88.9 % mesopore proportion) and a commercially available paraffinic PCM (n-hexadecane) following vacuum impregnation strategies. Corncob biochar combined with hexadecane exhibited an efficient energy per unit mass of 250.6 kJ kg−1 and a latent heat retention of 110.3 % after 500 consecutive thermal cycles. In addition, the corncob biochar/hexadecane composite demonstrated high fractional crystallinity and relative latent heat efficiency (98.9 %). The composite exhibited promising chemical compatibility with composite components, stability, and competitive energy density even compared with a composite made of nonrenewable fossil-based materials, like exfoliated graphene nanoplatelets, which demonstrated reduced latent heat retention after multiple heating-cooling cycles. Intermolecular interactions, such as hydrogen bonding, between the guest molecular chains and host materials played a significant role in the thermal performance of the as-synthesized composite materials. This approach will contribute to overcoming the complexities and costs of composite PCM development in thermal management and thermal energy storage applications and support and advance the UN's sustainable development goal (affordable and clean energy).

Atomically Dispersed Metal Catalysts for the Conversion of CO2 into High-Value C2+ Chemicals.

The conversion of carbon dioxide (CO2) into value-added chemicals with two or more carbons (C2+) is a promising strategy that cannot only mitigate anthropogenic CO2 emissions but also reduce the excessive dependence on fossil feedstocks. In recent years, atomically dispersed metal catalysts (ADCs), including single-atom catalysts (SACs), dual-atom catalysts (DACs), and single-cluster catalysts (SCCs), emerged as attractive candidates for CO2 fixation reactions due to their unique properties, such as the maximum utilization of active sites, tunable electronic structure, the efficient elucidation of catalytic mechanism, etc. This review provides an overview of significant progress in the synthesis and characterization of ADCs utilized in photocatalytic, electrocatalytic, and thermocatalytic conversion of CO2 toward high-value C2+ compounds. To provide insights for designing efficient ADCs toward the C2+ chemical synthesis originating from CO2, the key factors that influence the catalytic activity and selectivity are highlighted. Finally, the relevant challenges and opportunities are discussed to inspire new ideas for the generation of CO2-based C2+ products over ADCs.

Modelling environmental life cycle performance of alternative marine power configurations with an integrated experimental assessment approach: A case study of an inland passenger barge

There is pressure on the global shipping industry to move towards greener propulsion and fuel technologies to reduce greenhouse gas emissions. Hydrogen and electricity are both recognised as pathways to achieve a net-zero. However, in the evaluation of the environmental performance of these alternative marine power configurations, conventional life cycle assessment (LCA) methods have limitations reflecting the varied nature of ship design and operational modes. The integration of LCA with experimental assessment could remedy the shortcoming of conventional approaches to data generation. The system energy demand data in this study was generated based on specific ship design and directly fed into life cycle assessment. To demonstrate the effectiveness and potential the approach was applied to a case study of inland waterway vessel. Suitable hybrid PV/electricity/diesel and hydrogen powered fuel cell systems for the case vessel were modelled; and hydrodynamic testing and dynamic system simulation was undertaken to provide ship performance data under various operational/environmental profiles. Lifecycle assessment (LCA) indicated hydrogen and electrical propulsion technologies have the potential for 85.7 % and 56.2 % emissions reduction against an MGO base case, respectively. The results highlight that implementation of both technologies is highly dependent on energy production pathways. Hydrogen systems reliant on fossil feedstocks risk an increase in emissions of up to 6.3 % against the MGO base case. Sensitivity analysis indicated an electrical system with electricity production from 79.5 % renewables could achieve savings of 82.2 % in GHG emissions compared to the MGO base case. Crucially, the results demonstrate a further development of the LCA approach which can enable a more accurate environmental performance evaluation of alternative marine power configurations considering specific ship design and operational characteristics. Ultimately this addition makes the results more meaningful for commercial operations and decision making in the selection of alternative marine power systems to support the transition to net-zero.

Gasification for material recycling—A solution to the plastic flood?

AbstractSince 1950, only 9% of all plastic produced has undergone recycling, and a mere 10% of that has been recycled multiple times. Most discarded plastic (around 73%) ends up in landfills or is improperly managed, resulting in widespread littering. The main reason for low recycling rates is the lack of recycling technology for multi‐polymer and multi‐layer materials and unsortable mixed plastic waste. This plastic waste is one of the most accumulating types, including for example single‐use food packaging with an average lifetime of less than 6 months. These multi‐layer films, consisting of various polymer types, are not feasible for traditional mechanical recycling, which requires well‐sorted, clean, and homogeneous materials. Several methods for plastic recycling have been proposed to address this issue and tackle the overwhelming influx of plastic waste, among which steam gasification stands out as one of the most promising approaches for recycling mixed, contaminated, and unsortable plastics. This method utilizes high temperatures (800°C) to atomize the plastics, resulting in a gas mixture of , CO, and and small hydrocarbons. The resulting gas can be reformed through hydrocarbon syntheses, for example, via methanol to propylene and ethylene, and successive into new mono‐ and polymers of equal quality to fossil‐based plastics. Moreover, since the high temperatures atomize any organic structure, biomass can be used as a substitute for an extension of the carbon feed, ultimately reducing reliance on fossil feedstock. With these advantages, steam gasification can significantly increase recycling rates and contribute to a bio‐integrated circular carbon economy.

Sustainable Aviation Fuel Production through Catalytic Processing of Lignocellulosic Biomass Residues: A Perspective

Currently, the transportation sector represents about one third of the total energy consumed in the world, most of this energy being obtained almost exclusively from oil. However, the world is changing, as well as the aviation industry. Since lignocellulosic biomass is a low-cost feedstock that does not compete with food, it has drawn great attention as one of the most attractive alternatives to replace fossil feedstocks for the production of fuels. Renewable jet fuels could have a significant impact on lowering greenhouse gas emissions and providing a long-term sustainable alternative to petroleum-derived fuels. However, the catalytic upgrading of lignocellulosic residues in industry still remains a big challenge and the development of highly integrated systems that allow the direct conversion of lignocellulosic wastes is essential to achieve that goal. The importance of renewable jet fuels and the potential of lignocellulosic biomass have already been extensively reviewed. However, this work presents a new perspective on the main catalytic routes and challenges for the sustainable production of aviation fuels from biomass wastes.

Using the benzenepolycarboxylic acid (BPCA) method to assess activated biochars and their PFAS sorption abilities

Activated carbon (AC) has important industrial and environmental applications as it has excellent abilities to sorb contaminants such as per- and polyfluoroalkyl substances (PFAS). Current research aims to develop activated biochars (AB) from renewable biomass to replace AC that is produced from fossil feedstock. Both AC and AB are primarily comprised of condensed aromatic carbon (ConAC), the component that is the focus of this study. ConAC is characterized to determine its relationship with biochar activation conditions and PFAS sorption, which are understudied at present.Benzenepolycarboxylic acid (BPCA) markers for ConAC were quantified in steam-activated biochars (AB-Steam) and carbon dioxide-activated biochars (AB-CO2) prepared from waste timber at different temperatures (800, 850, 900 °C) and molar ratios of feedstock-carbon:steam (0.50 – 1.25). A non-activated biochar was also included as a reference. ConAC relative to total organic carbon content was higher in AB-Steam than in AB-CO2 (92 ± 2 % vs. 81 ± 11%). The ratio of benzenehexa- (B6CA) to benzenepentacarboxylic (B5CA) acids revealed that AB-Steam also had larger ConAC clusters than AB-CO2. These findings provide novel evidence that steam activation is more effective than CO2 activation in creating ConAC.To assess how ConAC impacts AB sorption abilities, AB-Steam were used to remediate PFAS from contaminated soils. The observed strong correlations between ConAC content and sorption of long-chain PFAS suggest the importance of hydrophobic interactions between PFAS tails and ConAC. Poor correlations for short-chain PFAS, on the other hand, indicated the existence of electrostatic repulsion interactions between PFAS head groups and ConAC. Collectively, these results explain the great ability of AB-Steam to sorb PFAS from contaminated soils (up to 100% remediation). More broadly, this work demonstrates that the BPCA method can be a valuable tool to assess the quality of biochars and other carbonaceous sorbents in relation to their production conditions or contaminant sorption abilities.

Construction of plasmonic CuS/attapulgite nanocomposites toward photothermal reforming of biomass for hydrogen production

As a naturally abundant resource, biomass holds significant potential as an alternative to non-renewable fossil feedstock for producing value-added chemicals and fuels. However, its applications are limited by low conversion efficiency and product selectivity. In this study, we synthesized plasmonic CuS/phosphoric acid-modified attapulgite (P-ATP) nanocomposites using a microwave hydrothermal approach. The formation of an S-type heterostructure between CuS and P-ATP markedly improved the separation of electrons and holes. Additionally, the CuS/P-ATP nanocomposites featured numerous acidic sites, significantly enhancing the conversion of 5-hydroxymethylfurfural (HMF) into furan-2,5-dicarbaldehyde (DFF). CuS-induced localized surface plasmon resonance (LSPR) extended the absorption spectrum into the near-infrared region, raising the surface temperature and substantially improving photocatalytic activity. The 30 % CuS/P-ATP exhibited the highest hydrogen evolution rate of 286 μmol g−1 h−1 and the highest DFF generation rate of 31 μmol g−1 h−1, while maintaining a 95 % selectivity for DFF. This study demonstrates the commercial potential of clay minerals for biomass valorization coupled with hydrogen production.

The catabolism of lignin-derived p-methoxylated aromatic compounds by Rhodococcus jostii RHA1.

Emergent strategies to valorize lignin, an abundant but underutilized aromatic biopolymer, include tandem processes that integrate chemical depolymerization and biological catalysis. To date, aromatic monomers from C-O bond cleavage of lignin have been converted to bioproducts, but the presence of recalcitrant C-C bonds in lignin limits the product yield. A promising chemocatalytic strategy that overcomes this limitation involves phenol methyl protection and autoxidation. Incorporating this into a tandem process requires microbial cell factories able to transform the p-methoxylated products in the resulting methylated lignin stream. In this study, we assessed the ability of Rhodococcus jostii RHA1 to catabolize the major aromatic products in a methylated lignin stream and elucidated the pathways responsible for this catabolism. RHA1 grew on a methylated pine lignin stream, catabolizing the major aromatic monomers: p-methoxybenzoate (p-MBA), veratrate, and veratraldehyde. Bioinformatic analyses suggested that a cytochrome P450, PbdA, and its cognate reductase, PbdB, are involved in p-MBA catabolism. Gene deletion studies established that both pbdA and pbdB are essential for growth on p-MBA and several derivatives. Furthermore, a deletion mutant of a candidate p-hydroxybenzoate (p-HBA) hydroxylase, ΔpobA, did not grow on p-HBA. Veratraldehyde and veratrate catabolism required both vanillin dehydrogenase (Vdh) and vanillate O-demethylase (VanAB), revealing previously unknown roles of these enzymes. Finally, a ΔpcaL strain grew on neither p-MBA nor veratrate, indicating they are catabolized through the β-ketoadipate pathway. This study expands our understanding of the bacterial catabolism of aromatic compounds and facilitates the development of biocatalysts for lignin valorization.IMPORTANCELignin, an abundant aromatic polymer found in plant biomass, is a promising renewable replacement for fossil fuels as a feedstock for the chemical industry. Strategies for upgrading lignin include processes that couple the catalytic fractionation of biomass and biocatalytic transformation of the resulting aromatic compounds with a microbial cell factory. Engineering microbial cell factories for this biocatalysis requires characterization of bacterial pathways involved in catabolizing lignin-derived aromatic compounds. This study identifies new pathways for lignin-derived aromatic degradation in Rhodococcus, a genus of bacteria well suited for biocatalysis. Additionally, we describe previously unknown activities of characterized enzymes on lignin-derived compounds, expanding their utility. This work advances the development of strategies to replace fossil fuel-based feedstocks with sustainable alternatives.

Plastic recycling stripped naked - from circular product to circular industry with recycling cascade.

This perspective combines various expertise to develop and analyse the concept of technology cascade for recycling waste plastics with the goal of displacing as much fossil crude oil as possible. It thereby presents archetype recycling technologies with their strengths and weaknesses. It then combines them in various cascades to process a representative plastic mix, and determines how much (fossil) naphtha could be displaced and at which energy consumption. The cascades rely on a limited number of parameters that are fully reported in supplementary information and that were used in a simple and transparent spreadsheet model. The calculated results bust several common myths in plastic recycling, e. g. by prioritizing here recycled volume over recycling efficiency, and prioritizing circular industry over circular products . It unravels the energy cost of solvent-based recycling processes, shows the key role of gasification and the possibility to displace up to 70 % of the fossil feedstock with recycled carbon, a recycling rate that compares well with that aluminium, steel or paper. It suggests that deeper naphtha displacement would require exorbitant amount of energy. It therefore argues for the need to complement recycling with the use of renewable carbon, e. g. based on biomass, to fully defossilise the plastic industry.

Large-scale atomistic model construction of subbituminous and bituminous coals for solvent extraction simulations with reactive molecular dynamics

Large-scale atomistic models for complex polycyclic aromatic hydrocarbon systems help understand the chemical properties and behaviors of complex feedstocks such as coal or petroleum. However, the development and utilization of large-scale models remain limited due to the difficulty in achieving the varied structural characteristics necessary to capture stochastic nature of these feedstocks. We demonstrate a systematic workflow to construct stochastic molecular systems from a broad analytical suite: high-resolution transmission electron microscopy (HRTEM), carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), laser desorption ionization mass spectroscopy (LDI-MS), and elemental analysis. We present a model construction and analysis utility of a new Python-based module. We selected one subbituminous and three high-volatile bituminous coals to construct large-scale models (∼40,000 atoms). The constructed models were utilized to examine the affinity for solvent extraction (naphthalene or tetralin) and the effect of structural properties (e.g., aromatic cluster size, functional groups, and cross-linking) in reactive molecular dynamics simulations. Complex chemical reactions were monitored with bond order transitions, intermediates formation, and mass distributions. Reactive molecular dynamics simulations suggest a plausible chemical extraction process and products for the complex fossil feedstocks. The results indicated that radical formations with bond breaking of bridging oxygens and carbons were required at high temperatures to facilitate hydrogeneration and extraction of gas molecules from radical-free molecules. We observed that aliphatic chains of tetralin were easily decomposed and combined with radicals to form small size of molecules with aryl bonding, mainly increasing molecules in the 500–1000 Da, while naphthalene had little impact on chemical extraction process.

Feasibility of wood as a renewable carbon feedstock for the production of chemicals in Europe

AbstractIn transitioning to a carbon‐neutral chemical industry, the intake of fossil feedstocks will have to be reduced by maximizing end‐of‐life product recycling and introducing alternative feedstocks based on renewable carbon. This perspective article analyses the potential of domestically grown and sourced woody biomass for the supply of renewable carbon for chemicals in Europe. The European chemical industry can become a major consumer of woody biomass in a context where burning wood for energy production is viewed as an unsustainable practice.

Entrained flow gasification-based biomass-to-X processes: A techno-economic assessment

In the pursuit of a successful energy transition, synthetic basic chemicals and fuels, alongside renewable energies, play pivotal roles. This study focuses on the utilization of biomass as a carbon source to replace conventional fossil feedstocks, conducting detailed process simulations and techno-economic analyses for various biomass-to-x pathways. Six key products—Methanol, Dimethyl Ether, Methane (SNG), Fischer-Tropsch syncrude, Hydrogen, and Ammonia—derived from entrained flow gasification of a representative biomass are systematically compared. The uniformity of simulation detail and economic methodology enables a direct and comprehensive comparison of these products. Notably, carbon-based products exhibit up to 34% lower average investment costs compared to their hydrogen-based counterparts, namely ammonia and hydrogen. This cost discrepancy is reflected in the levelized costs of manufacturing, with hydrogen-based products emerging as the most energy-expensive. The analysis identifies variable costs as the primary contributor to overall costs with around 50%, followed by fixed investment. The study underscores the critical impact of full load hours, plant lifetime, and feedstock costs on results. This emphasise the importance of detailed planning if alternative feedstock is used to balance fuel costs and enhance plant availability. Among the evaluated products, methanol emerges as the most promising across the evaluated KPIs with costs of 283.48 € MWh−1. However, regarding hydrogen-based products, it is suggested that, especially in the context of CO2 abatement costs, a comprehensive consideration of the long-term system effects is essential to prevent misinvestments during the early stages of the energy transition. This emphasizes the need for strategic planning to ensure a sustainable and economically viable shift towards biomass-derived synthetic fuels.

Biobased Glycols – Towards the Use of Solid Bases in the Hydrogenolysis of Sorbitol

AbstractIn this study, mixed metal oxides of alkaline earth metals and Ti or Zr were synthesized and investigated as solid bases in the hydrogenolysis of sorbitol in combination with Ru/C. Desired products of this reaction are glycols, which are today produced from fossil feedstock and find application as monomers or anti‐freezes. The most promising mixed metal oxide CaZr−O possesses CaO, Ca(OH)2, perovskite and ZrO2 phases. CaO and Ca(OH)2 leach out over the reaction making the solid a depot for the homogeneous base. Additionally, catalytic activity also results from a synergistic effect of the solid perovskite and ZrO2 phases increasing the sum of liquid phase products. After an optimization of the process parameters, a maximum selectivity to glycols of 50 % was achieved at 74 % conversion within 4 h at 220 °C.

Two-Dimensional Zeolites-Potential Catalysts for Biomass Valorization.

Valorization of biomass and biomass-derived molecules has become a viable route to get fuels and useful chemicals as fossil feedstocks are dwindling and the demand for renewable feedstocks and sustainable energy sources are rising. Zeolites have been promising catalysts for biomass conversion owing to their structural features and active sites. However, the use of conventional zeolites was limited due to molecular diffusion constraints, which paved the way for the emergence of two-dimensional (2D) zeolites. The high external surface area, bimodal porosity (micropores and mesopores), and 2D structure of these zeolites envisage smooth diffusion of bulky molecules, enhanced accessibility to active sites, and slow deactivation, which are benefits in the valorization of biomass. In this brief review, current advancements in the use of layered 2D zeolites for biomass conversions are discussed. The relationship between the structural features and the catalytic potential of 2D zeolites in some of the major biomass conversion processes like pyrolysis, hydrodeoxygenation, alkylation, acetalization, condensation, and dehydration is discussed and multistep reactions that proceed via a cascade mechanism are highlighted.