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Replacing petrochemicals with refined waste biomass as a sustainable chemical source has become an attractive option to lower global carbon emissions. Popular methods of refining lignocellulosic waste biomass use thermochemical processes, which have significant environmental downsides. Using electrochemistry instead would overcome many of these downsides, directly driving chemical reactions with renewable electricity and revolutionizing the way many chemicals are produced today. This review mainly focuses on two furanic platform chemicals that are produced from the dehydration of cellulose, 5-hydroxymethylfurfural and furfural, which can be electrochemically reduced or oxidized to replace fuels and monomers that today are obtained from petrochemicals. Critical parameters such as electrode materials and electrolyte pH are discussed in relation to their influence on conversion efficiency and product distribution. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'. [ABSTRACT FROM AUTHOR]

Ethylene glycol (EG) is an industrial chemical with multiple applications in polymers, anti-freeze agents, coolants, desiccants and de-icing fluids. It is prepared mainly from fossil feedstock resources. However, its manufacture from renewable sources like lignocellulosic biomass is attractive from the view points of carbon-neutrality and environmental benefits. A few industries have already ventured or committed to produce biomass-derived EG (bio-EG) on a pilot to demonstration scale. At present bio-EG is more expensive than the EG made from fossil resources. Advances are happening in developing more efficient and selective catalysts for the direct conversion of raw biomass and its hydrolysis products (cellulose and glucose) into bio-EG. This review presents the recent advances in catalysts for producing bio-EG. [ABSTRACT FROM AUTHOR]

5‐Hydroxymethylfurfural (HMF) is a widely used biomass platform chemical that plays a crucial role in bridging biomass and fossil resources. Electrocatalytic oxidation of HMF provides an efficient way to obtain high‐value‐added biomass‐derived chemicals, among which the intermediate product 5‐formyl‐2‐furan carboxylic acid (FFCA) has attracted considerable attention. However, the weak adsorption ability of monometallic nickel oxide (NiOx) to HMF in neutral electrolyte restricts its further development, resulting in low HMF conversion and FFCA yield. In this study, we successfully constructed a novel nickel oxide‐platinum oxide hybrid catalyst supported on carbon felt (NiOx‐PtOx/CF), which exhibits an optimized adsorption ability of HMF, leading to the outstanding FFCA yield up to 77 % in the neutral media. The high activity of the NiOx‐PtOx/CF catalyst can be attributed to the redistribution of the electrons and the optimization of the electronic structure on the Ni active site due to the introduction of PtOx on NiOx nanosheets. This study offers valuable insights for the design of efficient multicomponent electrocatalysts for electrocatalytic biomass refinery systems. [ABSTRACT FROM AUTHOR]

Meeting aggressive decarbonization targets set by the International Civil Aviation Organization (ICAO) will require the rapid development of technologies to produce sustainable aviation fuel (SAF). Catalytic fast pyrolysis (CFP) can support these efforts by opening pathways for the conversion of woody biomass into an upgraded biogenic oil that can be further processed to SAF and other fuels. However, the absence of end-to-end experimental data for the process leads to uncertainty in the yield, product quality, costs, and sustainability of the pathway. The research presented here serves to address these needs through a series of integrated experimental campaigns in which real biomass feedstocks are converted to a final SAF product using large bench-scale continuous reactor systems. For these campaigns, the degree of catalytic upgrading during CFP was varied to produce CFP-oils with oxygen contents of 17 and 20 wt% on a dry basis. The CFP-oils were then hydrotreated and distilled into gasoline, diesel, and SAF fractions. Detailed yield and compositional data were obtained for each step of the process to inform technoeconomic and lifecycle analyses, and the fuel properties of the SAF fraction were evaluated to provide first-of-its-kind insight into the quality of the final product. This research reveals opportunities to optimize process carbon efficiency by tuning the degree of catalytic upgrading during the CFP step and highlights routes to produce a high-quality cycloalkane-rich SAF with 85-92% reduction in greenhouse gas emissions compared to fossil-based pathways. [ABSTRACT FROM AUTHOR]

Torrefaction is an effective method to improve the quality of biomass feedstocks for a subsequent thermal conversion process. Torrefaction has been widely developed for biomass upgrading in terms of increasing bulk and energy densities, reducing water and oxygen contents, and improving hydrophobic properties, which are favorable for transportation and storage. Moreover, the torrefied biomass can be easily ground to even particle sizes, which favor the downstream thermochemical conversion process such as gasification. This paper reports on the progress in the dry and wet torrefaction of biomass sources. Key findings and challenges of torrefied biomass gasification are highlighted as well. In general, the properties of biomass feedstocks can be improved by the torrefaction process. Torrefaction for biomass gasification can improve the quality of syngas. In particular, gasification of torrefied biomass involves a merit of volatile matter (tar precursor) removal prior to the gasification process. The properties of torrefied biomass are significantly affected by the torrefaction conditions mainly including atmosphere, temperature, and pressure. The presence of an appropriate amount of oxygen gas leads to a superior performance for biomass torrefaction. The oxygen-containing gas and the waste heat from industrial flue gas can be utilized to reduce the operating cost, thus making the biomass torrefaction pretreatment more commercially feasible. [ABSTRACT FROM AUTHOR]

Biomass–derived feedstocks for hydrogen production are crucial as an alternative to fossil fuel especially in those areas where green electricity and clean water are scarce. In this framework the transformation of simple (formic acid, alcohols) and more complex (polyalcohols, sugars and cellulose) bio–derivatives in pure hydrogen is recognized as a promising approach. Parallel to great effort in heterogeneous catalysis, milder molecular systems represent a more selective eye for alternative solutions and mechanistic insights. In the present review the introduction summarizes the challenges in the catalytic utilization of biomass–derived feedstocks, followed by the advances in homogeneously catalyzed hydrogen production from different substrates which will cover formic acid, with oustanding efficiency with noble metals and promising results with earth abundant ones and alcohols and polyalcohols, with particular emphasis to the development of heterogenized systems, ligand assisted catalysts and bi‐catalytic synergistic solutions which allow to avoid base and to promote catalyst stability and recyclability. In the last part, description of hydrogen production from more complex substrates, such as sugars and cellulose, will show the role of molecular complexes in main and side reactions. Critical comments on the reported advances are provided along the whole discussion. [ABSTRACT FROM AUTHOR]

Interest has emerged recently in addressing the long‐standing issue of waste plastic disposal and environmental challenges through the co‐liquefaction of waste plastics with eco‐friendly renewable biomass resources, including microalgae biomass and lignocellulosic biomass, to produce biofuels. Co‐liquefaction provides a viable alternative for managing plastic waste while contributing to biofuel production. The purpose of this article is to provide a comprehensive review of the advances in the co‐liquefaction of various mixtures of plastic waste and different types of biomass feedstocks (lignocellulosic and algal) for the production of biofuels. The influence of various reaction parameters, such as feedstock composition (blending ratio), temperature, catalyst type and loading, solvents, and reaction time on the product yield are explored. The synergistic interaction during the co‐liquefaction of biomass and plastic and the distribution and properties of biofuel products are also discussed. The findings demonstrate that maximum product yields vary depending on the final temperature, and the blending ratio plays a crucial role in determining the distribution of liquefaction products. Of particular interest is biocrude oil, the components of which are influenced by the composition of the feedstock material. The distribution of organic elements in the biochar is contingent upon the type of plastic used. Although the analysis of gas‐phase components is often overlooked, the reaction medium's composition is shown to impact the resulting gas composition. Finally, based on the insights gleaned from the literature, this review presents future perspectives on the subject matter. In general, the co‐liquefaction process offers a viable option for sustainable biofuel production and is a promising approach to address the waste plastics disposal challenges effectively, contributing to the valorization of plastic waste to achieve a circular bioeconomy in the future. [ABSTRACT FROM AUTHOR]

This study investigates the correlation between both the chemical compositions and physicochemical properties of pretreated oil palm empty fruit bunch (OPEFB) fibre and their enzymatic saccharification/total glucose yield (TGY). Twenty OPEFB samples, pretreated with various aqueous pretreatments, with diverse cellulose (25.63–44.23%), hemicellulose (0.01–42.49%), and lignin (3.7–47.1%) levels, were examined for their correlation with TGY (8.5–40%). The quadratic regression model was verified significant (p-value = 0.0006, R2 = 0.8006). It was found that the pre-refined OPEFB experienced greater cellulose loss (35%) compared to unrefined ones (9%), adversely affecting TGY. Among physicochemical properties analysed using SEM, FTIR, XRD, Py-GCMS, and XPS, only crystallinity index (CrI) was significantly correlated with TGY based on theoretical glucose concentration (TGC) (R2 = 0.77, 0.91). Other characteristics (morphology, functional groups, crystallite size, S/G ratio, and O/C ratio) exhibited no significant correlation to saccharification efficiency, exhibiting random trends (R2 < 0.5). OPEFB fibres with CrI of 30–40 could achieve 100% TGY based on TGC. In conclusion, regardless of pretreatments, chemical compositions predominantly affected TGY in the enzymatic saccharification of biomass. Among commonly used physicochemical analytical methods, CrI is most significant in this evaluation and OPEFB should be unrefined before treatment to avoid cellulose loss. [ABSTRACT FROM AUTHOR]

This study investigates the gasification of cellulose, lignin, corn stover (rich in cellulose) and walnut shells (rich in lignin) using CaO as a catalyst. The objective was to understand the effect of the different biomass components on the gasification products and the performance of the CaO catalyst. Notable results indicate distinctive product distribution: cellulose yields higher liquid (58%) and CO (95.36%) products, while lignin produces increased H2 (47.88%), CH4 (34.34%), and CO2 (29.58%). Gasification of biomass feedstocks, corn stover (cellulose-rich) and walnut shell (lignin-rich), aligns with pure cellulose and lignin trends. Catalyst characterization highlights that cellulose exhibits a greater tendency for coke formation, leading to elevated tar compounds and coke deposition on the catalyst surface. The solid residue from cellulose gasification displays a smaller pore volume (5.70 m2/g) and specific surface area, indicating undesirable catalyst rearrangement. XRD analysis indicates a higher carbonation rate of CaO in lignin-rich gasification, leading to increased CaCO3 formation. Further results show a higher CO2 concentration (3.35 mol/kg) and lower CO production (0.54 mol/kg) in corn stover gasification, contrasting with walnut shell (CO2: 14.24 mol/kg, CO: 1.24 mol/kg). The study underscores the quantitative assessment of biomass composition for optimizing gasification processes, vital for catalyst selection and ensuring efficient CO2 capture in industrial applications. [ABSTRACT FROM AUTHOR]

The development of biodegradable materials from biomass is a crucial strategy for leveraging biomass resources. A key component in this process is 2,5-bis(hydroxymethyl)furan (BHMF), a significant biomass-derived platform chemical. However, producing BHMF with high selectivity through the selective hydrogenation of 5-hydroxymethylfurfural, while avoiding the creation of unwanted byproducts, is a complex challenge. In our research, we have developed a novel catalyst featuring a magnetic core. This catalyst, which consists of platinum loaded onto a graphene-like shell, has been applied to the catalytic hydrogenation of HMF in an aqueous environment. Under the optimized conditions of 373 K, 3 MPa H2, and 1 h reaction time, a BHMF yield exceeding 99% was achieved. This method presents a promising and effective approach for the high-value conversion of biomass waste into polymer materials and pharmaceutical chemicals. [ABSTRACT FROM AUTHOR]

We developed a series of heteropolyacid-modified lignin-MOF derived bimetallic catalyst for the efficient in situ hydrogenation/hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural using isopropanol as hydrogen-donating solvent. [Display omitted] Catalytic conversion of biomass-derived value-added chemicals was of great significance for the utilization of renewable biomass resources to instead of fossil chemicals. Biomass-derived lignin was regarded as an important support and 5-hydroxymethylfurfural (HMF) was a vital platform chemical derived from cellulose. Herein, a series of lignin-MOF hybrid catalysts were prepared and modified with different heteropolyacids (HPAs), which were then successfully introduced into the selective conversion of HMF to 5-hydroxymethylfurfuryl alcohol (MFA). The effect of different HPA, calcination temperature, etc. were all studied, and all catalysts were well characterized. It was confirmed that silicotungstic acid modified catalyst (Ni 3 Co-MOF-LS@HSiW) exhibited the best catalytic performance, while the highest conversion of HMF was up to 100%, with the best MFA yield of 86.5%. The finding in this study could provide novel insights for the utilization of lignin and preparation of value-added biomass-derived chemicals. [ABSTRACT FROM AUTHOR]

γ‐Valerolactone (GVL) derived from non‐edible biomass resources has attracted much intense attention from both academia and industry, due to its excellent properties as green solvent and ideal renewable feedstock for production of bioenergy and biorefinery. However, the practical application of current synthetic technologies is restricted by complicated catalyst system and high production cost so far. Here we report a simple but highly efficient method to realize one‐pot synthesis of bio‐derived GVL by a series of Lewis acidic triflates (M(OTf)3 (M=Sc3+, Ln3+)) under mild condition, achieving up to 78 % GVL yield from furfural (FUR) without any additives or pretreatments. Systematic mechanistic studies, including reaction monitoring, identification of key intermediates and deuterium control experiments disclose the nature of such one‐pot conversion by all‐in‐one Sc(OTf)3. This system exhibits several excellent features such as commercially available and inexpensive catalyst, 100 % carbon atom‐economy, environmentally friend, simple preparation and separation procedures. This method could also be applied to the upstream raw materials, including xylose, hemicellulose and even corncob, achieving GVL in 36 %, 35 % and 21 % yields in one‐pot manner, respectively. [ABSTRACT FROM AUTHOR]

This study investigated the integrated valorization of defatted rice bran (DRB) by converting it into lactic acid (LA) and subsequently utilizing the residues from LA production for biomethane generation through anaerobic digestion (AD). Processing 480 kg of DRB resulted in the production of 70 L of pure LA and generated significant waste streams, primarily consisting of 572 kg of decanted hydrolysate pellet (Pellet DEC) and 220 kg of microfiltration retentate (Retentate MF). Exceptionally high methane yields of 374-434 LN kgVS -1 were observed for residues from LA fermentation in biochemical methane potential tests, indicating their high potential for biogas production. During long-term semi-continuous AD, varying organic loading rates (OLRs) from 0.5-2.5 kgVS m-3 d-1 demonstrated feedstock- and OLR-dependent methane production. Reactor failure at higher OLRs was attributed to the accumulation of total ammoniacal nitrogen (TAN). The co-digestion of Pellet DEC and Retentate MF proved to be more resilient, with OLRs up to 2 kgVS m-3 d-1, mitigating TAN inhibition. Methane yields, ranging from 265-334 LN kgVS-1 before reaching inhibitory OLR levels, were higher than those found in the literature. Process integration has emerged as a promising approach because the biogas generated from residues could effectively offset the energy demands of LA production. Supported by life cycle assessment, the integrated processes showed a 67% lower environmental impact at the midpoint and a 71% lower environmental impact at the endpoint, along with an 80% reduction in energy costs compared to the standalone LA production. Results proved a significant enhancement of the sustainability and economic viability of this integrated biorefinery approach. [ABSTRACT FROM AUTHOR]

Biochar is a carbon-rich product obtained by pyrolyzing biomass under oxygen-limited conditions and has a wide range of potential for environmental applications. In particular, dissolved organic matter (DOM) released from biochar has an important impact on the fate of pollutants. The study aimed to systematically assess how varying pyrolysis temperatures and biomass feedstocks influence the characteristics of biochar-derived DOM. DOM samples were comprehensively characterized utilizing UV-vis spectroscopy and excitation–emission matrix (EEM) fluorescence spectroscopy, coupled with parallel factor (PARAFAC) analysis. The study discovered that pyrolysis temperature significantly affects DOM characteristics more than feedstock type. An increase in pyrolysis temperature correlated with a notable decrease in dissolved organic carbon content, aromaticity, and fluorescence intensity, alongside a marked increase in pH and hydrophilicity. PARAFAC analysis identified three distinct DOM components: two humic-like substances (C1 and C2) and one protein-like substance (C3). The proportion of protein-like substances increased with higher pyrolysis temperatures, while the humic-like substances' proportion declined. The compositional shifts in DOM with pyrolysis temperature may significantly influence its environmental behavior and functionality. Further research is necessary to explore the long-term environmental impact and potential applications of biochar-derived DOM. [ABSTRACT FROM AUTHOR]

Biomass feedstocks are established as a key resource and a viable alternative for an economy less dependent on fossil inputs. This review offers an examination exemplified by fresh references covering strategies to reach a sustainable conversion of biomass to emerging chemicals and materials. Biobased chemicals lead to reduced climate change impacts compared with their fossil‐based counterparts. There is a broad range of products that can be targeted for biobased production, and it is important to select both the feedstocks and the target chemicals, which have a positive environmental impact and opportunity of commercial success. From the perspective of polymer science, we summarize emerging polymers that can be derived from biomass with promising properties. Furthermore, as challenges in the field of emerging biobased materials and chemicals are driven both by performance constraints and economic factors, we also examine recent progress in catalytic and biochemical process towards successful end products. [ABSTRACT FROM AUTHOR]

The activated carbons (ACs) derived from okara powder waste with high surface areas were modified with ammonia aqueous solution impregnation in an autoclave to enhance their CO2 adsorption properties. The impregnated ACs were characterized, where the chemical composition and properties of the ACs were analyzed by SEM-EDX and FTIR. Activated carbons were functionalized with ammonia aqueous solution (25%) through a hydrothermal process within 24, 48, and 72 h. The adsorption performance of CO2 onto carbon samples was experimentally evaluated through a TPD CO2 measurement. FTIR spectra confirm the N-containing in N-modified activated carbons and the presence of the –C=O stretch and N-H groups. CO2 uptakes of activated carbons are 0.24; 1.78; 2.24; and 1.26 mmol/g, which are relatively comparable with those of activated carbons studied in the literature. [ABSTRACT FROM AUTHOR]

Metal–water interfaces are central to understanding aqueous-phase heterogeneous catalytic processes. However, the explicit modeling of the interface is still challenging as it necessitates extensive sampling of the interfaces' degrees of freedom. Herein, we use ab initio molecular dynamics (AIMD) simulations to study the adsorption of furfural, a platform biomass chemical on several catalytically relevant metal–water interfaces (Pt, Rh, Pd, Cu, and Au) at low coverages. We find that furfural adsorption is destabilized on all the metal–water interfaces compared to the metal–gas interfaces considered in this work. This destabilization is a result of the energetic penalty associated with the displacement of water molecules near the surface upon adsorption of furfural, further evidenced by a linear correlation between solvation energy and the change in surface water coverage. To predict solvation energies without the need for computationally expensive AIMD simulations, we demonstrate OH binding energy as a good descriptor to estimate the solvation energies of furfural. Using microkinetic modeling, we further explain the origin of the activity for furfural hydrogenation on intrinsically strong-binding metals under aqueous conditions, i.e., the endothermic solvation energies for furfural adsorption prevent surface poisoning. Our work sheds light on the development of active aqueous-phase catalytic systems via rationally tuning the solvation energies of reaction intermediates. [ABSTRACT FROM AUTHOR]

In this research, based on kinetic and pyrolysis modelling, a model of 1-MW th biomass chemical looping gasification (BCLG) was prepared using the Aspen Plus process simulation software; the involved biomass feedstock was corn stover. The model reliability was verified using experimental data, and the energy and exergy performances of the modeled BCLG were analyzed in detail. Further, thermodynamic modelling was compared with kinetic modelling to determine the fuel utilization efficiency. In addition, the effects of operating conditions such as the gasification temperature, oxygen/carbon (O/C) ratio, and water/carbon (H 2 O/C) ratio on the modeled BCLG were investigated under steady-state conditions. Results revealed that the involved H 2 /CO ratio, syngas yield, and cold-gas efficiency were optimal at a gasification temperature of 850 °C, an O/C ratio of 0.45, and an H 2 O/C ratio of 0.6. Moreover, the heat output power and heat efficiency were 15.42% and 60.99%, respectively. In addition, the involved exergy destruction was found to primarily result from the fuel reactor (50.29%), with the total exergy destruction being 54.59%. The product exergy efficiency and total exergy efficiency of the model were 91.40% and 41.64%, respectively. Overall, this research aims to guide the stable operation of the demonstration plant as well as offer theoretical support and data accumulation for industrialized BCLG application. [Display omitted] • Biomass chemical looping gasification was modeled using kinetic and pyrolysis modelling. • Identified optimal operational conditions for maximizing syngas yield and cold gas efficiency. • The system heat efficiency of the kinetic model is increased by 22.27%. • Kinetic modelling has higher product exergy efficiency and total exergy efficiency. [ABSTRACT FROM AUTHOR]

Catalytic transformation of renewable biomass into value-added chemicals is an appealing strategy to upgrade biomass resources. Due to the presence of abundant oxygen-containing groups such as hydroxyl and aldehyde, biomass and its derived platform molecules have been served as ideal starting feedstock to synthesize valuable N-containing chemicals through reductive amination. In this mini review, we overviewed the recent advances in the reductive amination of several key bio-platform molecules including hydroxyl carboxylic acids, furfural, 5-hydroxylmethyl furfural and levulinic acid, with a focus on the production of amino acids, furan amines and pyrrolidones using thermocatalysis, electrocatalysis or photocatalysis. Moreover, the functions of active sites and the reaction mechanisms in different catalytic systems are discussed to get insights into the key factors in the reductive amination of biomass resources. [ABSTRACT FROM AUTHOR]

This review focuses on functional materials that contain terpyridine (terpy) units, which can be synthesized from biomass-derived platform chemicals. The latter are obtained by the chemical conversion of raw biopolymers such as cellulose (e.g., 2-furaldehyde) or lignin (e.g., syringaldehyde). These biomass-derived platform chemicals serve as starting reagents for the preparation of many different terpyridine derivatives using various synthetic strategies (e.g., Kröhnke reaction, cross-coupling reactions). Chemical transformations of these terpyridines provide a broad range of different ligands with various functionalities to be used for the modification or construction of various materials. Either inorganic materials (such as oxides) or organic ones (such as polymers) can be combined with terpyridines to provide functional materials. Different strategies are presented for grafting terpy to materials, such as covalent grafting through a carboxylic acid or silanization. Furthermore, terpy can be used directly for the elaboration of functional materials via complexation with metals. The so-obtained functional materials find various applications, such as photovoltaic devices, heterogeneous catalysts, metal–organic frameworks (MOF), and metallopolymers. Finally, some possible developments are presented. [ABSTRACT FROM AUTHOR]

The conversion of biomass to chemicals/fuels has emerged as a valuable solution that offers both environmental and economic benefits, with the transformation of carbohydrate into formic acid garnering escalating scholar interest. However, the relative limited efficiency of catalyzed-oxidation or expensive cost of H2O2 and alkali in wet hydrothermal oxidation impose limitations on industrialization. This paper proposed a new idea for formic acid production by O2-H2O2 co-oxidation of carbohydrate. A two-step reaction method was developed, where the initial step is engineered to regulate the carbon chain cleavage of carbohydrates to augment the production of active intermediate. Oxygen was employed in the subsequent step as effective oxidant through free radical mechanism, resulting in a formic acid yield of 82.6%. Theoretical calculation, intermediates detection and real time EPR confirmed the reaction mechanism. Finally, the universality of the reaction was verified by using disaccharides and polysaccharides such as cellulose as substrates. [ABSTRACT FROM AUTHOR]

The combination of chemo- and photocatalyses with biocatalysis, which couples the flexible reactivity of the photo- and chemocatalysts with the highly selective and environmentally friendly nature of enzymes in one-pot linear cascades, represents a powerful tool in organic synthesis. However, the combination of photo-, chemo- and biocatalysts in one-pot is challenging because the optimal operating conditions of the involved catalyst types may be rather different, and the different stabilities of catalysts and their mutual deactivation are additional problems often encountered in one-pot cascade processes. This review explores a large number of transformations and approaches adopted for combining enzymes and chemo- and photocatalytic processes in a successful way to achieve valuable chemicals and valorisation of biomass. Moreover, the strategies for solving incompatibility issues in chemo-enzymatic reactions are analysed, introducing recent examples of the application of non-conventional solvents, enzyme–metal hybrid catalysts, and spatial compartmentalization strategies to implement chemo-enzymatic cascade processes. [ABSTRACT FROM AUTHOR]

The supercritical water gasification (SCWG) of different kinds of feed including glycerol, lignin, humic acid, and ethylene glycol is investigated to predict product gas yields using a non-stoichiometric thermodynamic model. This model employs Gibbs free energy minimization, coupled with the penalty method as an optimization method. The results demonstrate excellent prediction accuracy for hydrogen yield, with average absolute relative deviations (AARDs) of 2.70%, 11.23%, and 0.17% for glycerol, humic acid, and ethylene glycol, respectively. Lignin prediction showed a higher AARD of 25.95%. Furthermore, the penalty method exhibited superior performance compared to the Lagrange method, achieving a reduction in error ranging from 66% to 88%. Moreover, the effect of reaction temperature and feed concentration on the molar gas yields was elucidated. This study establishes that the penalty method within the thermodynamic model effectively predicts product gas yields from biomass and bio-renewable feedstocks, with deviations below 10%. The developed thermodynamic model provides a reliable method for optimizing gasification processes, potentially improving the efficiency and accuracy of hydrogen production from diverse biomass and bio-renewable resources. This advancement supports the reduction in greenhouse gas emissions and promotes the use of sustainable energy sources. [ABSTRACT FROM AUTHOR]

A non-precious metal catalyst coated with carbon doped nitrogen supported cobalt by titanium oxide (Co/NC-TiO2-800) was prepared by hydrogen reduction at high temperature using poly (N-vinylimidazole), cobalt nitrate hexahydrate, and tetrabutyl titanate as the raw materials. The carbon network catalyst containing metal-nitrogen can effectively generate isolated active substances to catalyze the reduction amination reaction. Titanium oxide is introduced to stabilize cobalt nanoparticles on nitrogen-doped carbon, which enhances the stability of the catalyst. The samples were characterized by X-ray diffractometer (XRD), specific surface and aperture analyzer (BET), infrared spectrum analyzer (FT-IR), transmission electron microscope (TEM) and scanning electron microscope (SEM). The composition and structure of Co/NC-TiO2-800 were analyzed, and the active center and characteristics of Co/NC-TiO2-800 were revealed. The catalytic activity of Co/NC-TiO2-800 was tested using furfural reduction amination as the model reaction, and the reaction path was discussed. In addition, the effects of different nitrogen sources such as hydrazine hydrate, ammonia water and hydroxylamine hydrate on the reactivity were investigated. The results showed that the yield of furfuryl amine reached 99% at 100 °C and a H2 pressure of 2.0 MPa for 18 h with hydrazine hydrate as nitrogen source and hydrogen as hydrogen source. After 6 times of recycling, the catalytic activity is still high and has excellent stability. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) is a promising method for the conversion of agricultural and agro-industrial residues into valuable products. HTC processes biomass through chemical reactions that produce hydrochar, a carbon-rich solid similar to lignite. Unlike other thermochemical processes, HTC can handle high-moisture biomass without pre-drying. This article evaluates the efficiency of HTC on wood chips, wheat straw, and grape pomace, examining their chemical and structural characteristics and critical operational parameters such as the temperature, pressure, biomass/water ratio, and reaction time. The obtained results highlight that the two key process parameters are the temperature and the ratio between the solid biomass and liquid phase. Increasing the first parameter increases the energy content by 20% and increases the carbon concentration by up to 50%, while reducing the oxygen content by 30% in the hydrochar. Varying the second parameter leads to the alternating reduction of the ash content but simultaneously reduces the energy content. The reaction time seems to have a limited influence on the quality parameters of the biochar produced. Lastly, HTC appears to successfully enhance the overall quality of widely available agricultural wastes, such as grape pomace. [ABSTRACT FROM AUTHOR]

The elucidation of the ring–opening reaction mechanism is a critical step towards improving the catalytic performance for the conversion of biomass into value–added chemicals. Herein, we focused on the stepwise C−O bond hydrogenolysis mechanism of oxygen–containing heterocycles (O‐heterocycles) into α,ω‐diols, in particular THFA to 1,5‐PeD, over selective Ni−La(OH)3 in hydrogen–donor isopropanol. A mechanistic study was carried out on a structurally well–defined Ni−La(OH)3, where the mechanism was elucidated using a combination of kinetic and 13C NMR isotope labeling experiments. It was suggested that both Ni nanoparticles and La(OH)3 support play a critical role in the reaction mechanism, where basic hydroxide species of the support initially deprotonate the CH2OH and −OH modified furan, tetrahydrofuran and tetrahydropyran rings, adsorbing them chemically on the catalyst surface. This step is followed by a direct hydride attack on the second carbon atom of these rings, which is proposed to be the key step for ring cleavage, as indicated by the increased deuteration at this position. In addition to the direct hydrogenolysis using gaseous H2, it is assumed that a catalytic transfer hydrogenolysis reaction (CTH) reaction of THFA is proposed to proceed via the dehydrogenation of isopropanol over isolated Ni species, forming hydrogen species that can be adsorbed on the Ni surface or desorb as H2 molecules. [ABSTRACT FROM AUTHOR]

A simple, solvent‐free arginine‐catalyzed aldol dimerization of levulinic acid was achieved via the simultaneous formation of a eutectic mixture. Dimers of levulinic acid are valued as biomass‐derived fine chemical precursors, with potential to upgrade to bio‐jet fuels or N‐containing functional chemicals. Typically, these dimers are produced as isomeric mixtures using high temperatures and a variety of solid inorganic catalysts or mineral acids. In this study, an organocatalytic and regioselective dimerization was achieved at 22 % conversion on either a bench or kilogram scale using mild temperatures and only L‐arginine as both a co‐solvent and catalyst. The intricate H‐bonding network comprising the eutectic solvent was harnessed to produce only one product, minimizing side reactivity and preserving the reactants for recycling. [ABSTRACT FROM AUTHOR]

The "Felina 32" variety of industrial hemp (Cannabis sativa L.) is among the most popular cultivated varieties in Lithuania. In 2020 to 2021, the height of the above-ground portion of "Felina 32" ranged from about 1.37 to 2.52 m. In the less favorable year of 2021, 9.8% lower height and 28.5% lower mass plants grew. However, the impact of meteorological conditions on their comparative indicators was not confirmed. Two critical intervals were distinguished, which essentially influence the dynamics of plant growth: crop density of 90 to 150 plants·m2 and plant height of 1.9 m to 1.99 m. Lower crop density results in larger plants, and plants taller than 1.9 m gain mass 2.58 times faster than shorter plants. In addition, industrial hemp of different heights is characterized by differences in the development of morphological parts. This directly affects the physical and chemical properties of biomass. It was determined that when the height of "Felina 32" variety changes, the heat value of biomass increases 0.342 MJ/kg, carbon concentration increases 0.70%, and ash content, sulfur, nitrogen, and chlorine concentrations decreased. [ABSTRACT FROM AUTHOR]

The compound 5-(hydroxymethyl)furfural (HMF) has emerged as a versatile intermediate with the ability to undergo conversion into both fuel and a variety of platform chemicals. Lignocellulosic biomass, such as hazelnut shells and tea processing residues, was employed in this study for HMF production through two distinct methods. In the first method, cellulose from biomass was converted to sugars using a 4% acid solution, followed by catalytic conversion with NaCl/CrCl3.6H2O. After a 1-h reaction at 131 °C in a high-pressure system, HMF was obtained from tea processing waste and hazelnut shells with yields of 8.6% (82.3 mg/g) and 6.7% (66.7 mg/g), respectively. The second method involved LiCl/NaCldoped N,N-dimethylacetamide (DMA) as an ionic solvent system for HMF production. After a 2-h reaction at 131 °C in the DMA-NaCl/[EMIM]Cl ionic solvent system, HMF was obtained from tea processing waste and hazelnut shell celluloses with yields of 5.7% (57.5 mg/g) and 3.1% (31.3 mg/g), respectively. This study contributes to the economic conversion of various food wastes into valuable chemicals, highlighting the potential of lignocellulosic biomass in sustainable chemical production. [ABSTRACT FROM AUTHOR]

The increasing emergence of multidrug-resistant (MDR) pathogens causes difficult-to-treat infections with long-term hospitalizations and a high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treating MDR infections consists of inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS on mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks at 200–1000 °C in the limited presence of O2. Recently, it has been demonstrated that BC's capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2, or persulfate in the presence or absence of transition metals by electron transfer, thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC-containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs. [ABSTRACT FROM AUTHOR]

Current global challenges associated with energy security and climate emergency, caused by the combustion of fossil fuels (e.g., jet fuel and diesel), necessitate the accelerated development and deployment of sustainable fuels derived from renewable biomass-based chemical feedstocks. This study focuses on the production of long-chain (straight and branched) ketones by direct α-alkylation of short chain ketones using both homogenous and solid base catalysts in water. Thus, produced long-chain ketones are fuel precursors and can subsequently be hydrogenated to long-chain alkanes suitable for blending in aviation and liquid transportation fuels. Herein, we report a thorough investigation of the catalytic activity of Pd in combination with, (i) homogenous and solid base additives; (ii) screening of different supports using NaOH as a base additive, and (iii) a comparative study of the Ni and Pd metals supported on layered double oxides (LDOs) in α-alkylation of 2-butanone with 1-propanol as an exemplar process. Among these systems, 5%Pd/BaSO4 with NaOH as a base showed the best results, giving 94% 2-butanone conversion and 84% selectivity to alkylated ketones. These results demonstrated that both metal and base sites are necessary for the selective conversion of 2-butanone to alkylated ketones. Additionally, amongst the solid base additives, Pd/C with 5% Ba/hydrotalcite showed the best result with 51% 2-butanone conversion and 36% selectivity to the alkylated ketones. Further, the screening of heterogenous acid-base catalysts 2.5%Ni/Ba1.2Mg3Al1 exhibited an adequate catalytic activity (21%) and ketone selectivity (47%). [ABSTRACT FROM AUTHOR]

The selective hydrogenation of furfural (FFA) to furfuryl alcohol (FA) is regarded as attractive transformation to achieve the sustainable synthesis of value‐added chemicals from biomass resources. However, the conventional supported catalysts are significantly restricted by their narrow pore size, ununiform dispersion and easy leaching or aggregation of catalytic sites. Herein, we designed hollow UiO‐66‐NH2 as the support to encapsulate Pd nanoparticles (Pd@H‐UiO‐66‐NH2) to achieve the highly active and selective conversion of FFA to FA. Benefiting from the void‐confinement effect and substrate enrichment of hollow structure, as well as the surface wrinkles, the as‐prepared catalyst Pd@H‐UiO‐66‐NH2 exhibited 96.8 % conversion of FFA with satisfactory selectivity reaching up to 92.4 % at 80 °C, 0.5 MPa H2 in isopropanol solvent within 6 h. More importantly, as‐prepared Pd@H‐UiO‐66‐NH2 catalyst exhibited excellent long‐term stability, as well as good universality toward a series of hydrogenation of unsaturated hydrocarbons. [ABSTRACT FROM AUTHOR]

Carboxylic acids are widely available and generally inexpensive from abundant biomass feedstocks, and they are suitable and generic coupling partners in synthetic chemistry. Reported herein is an electroreductive coupling of stable and versatile carboxylic acids with (hetero)arenes using protons as the hydrogen source. The application of an earth-abundant titanium catalyst has significantly improved the deoxygenative reduction process. Preliminary mechanistic studies provide insights into the deoxygenative reduction of in-situ generated ketone pathway, and the intermediacy generation of ketyl radical and alkylidene titanocene. Without the necessity of pressurized hydrogen or stoichiometric hydride as reductants, this protocol enables highly selective and straightforward synthesis of various functionalized and structurally diverse alkylbenzenes under mild conditions. The utility of this reaction is further demonstrated through practical and valuable isotope incorporation from readily available deuterium source. Carboxylic acids are excellent theoretical candidates for alkylation reactions given their low cost and high availability as products from traditional and also modern feedstock derivatization reactions. Here the authors use simple carboxylic acids to functionalize the C–H bonds of electron-rich arenes under electroreductive conditions with a titanium catalyst. [ABSTRACT FROM AUTHOR]

This article explores the search for alternative energy and chemical sources in response to the depletion of fossil resources. It focuses on the synthesis of furanic diols from biomass feedstocks using a zinc/bismuth-mediated allylation reaction. The authors propose a user-friendly, inexpensive, and high-yielding green method for the synthesis of biobased diols. The article provides experimental results, optimization of reaction conditions, and a protocol for the synthesis of various allyl-substituted diols. It also includes chemical data and synthesis procedures for various compounds. The document concludes with an acknowledgment and dedication to Prof. Dennis Curran. [Extracted from the article]

Nanocellulose is increasingly important due to its abundance and sustainability sources, outstanding physicochemical properties, low density, high specific surface area, and easily modified surface chemistry. Nanocellulose is obtained from various sources, such as plants, algae, and bacteria, with plant-derived nanocellulose being the most common. Their presence significantly benefits many applications, especially in developing advanced materials for high end-use. Despite these benefits, the intrinsic hydrophilic behavior complicates dispersion in hydrophobic polymer matrices due to aggregation issues that result in deterioration properties. Nanocellulose modification and surface tuning are identified as fundamental approaches for improving the compatibility of the interfacial interaction between nanocellulose and polymer matrix to impart new functionalities to novel advanced materials. This article offers insight into nanocellulose by highlighting various lignocellulosic biomass sources and their chemical constituents. Three categories of nanocellulose are discussed in this review, including cellulose nanocrystals, cellulose nanofibrils, and bacterial nanocellulose. This article also featured several methods for promoting surface modification of nanocellulose to overcome the compatibility barrier between nanocellulose and polymer matrix to achieve a balanced hydrophilic-hydrophobic behavior. A few recent and emerging applications of nanocellulose-based composites are also presented in this review. [ABSTRACT FROM AUTHOR]

The demand for 2-ethylhexanol is rising in several sectors, yet this chemical is actually almost exclusively produced from petroleum resources, calling for sustainable alternatives. Here we review the production of 2-ethylhexanol from lignocellulosic biomass-derived chemicals with emphasis on 2-ethylhexanol synthesis and applications. 2-Ethylhexanol can be synthesized from ethanol, butanol, butyraldehyde, and syngas. Applications comprise biofuels, lubricants, plasticizers, and surfactants. [ABSTRACT FROM AUTHOR]

The phenol-based antioxidants as free radical scavengers are expected to continue increasing as additives in industries. As an antioxidant, lignin has low oxidative stability in pure solid form, so stabilization is needed to produce lignin-based antioxidants. This research focuses on the valorization of alkaline lignin by hydrogenolysis using a Pt/C catalyst and formic acid as a hydrogen donor. Three treatment variables, namely the amount of formic acid (FA), the amount of ethanol (EtOH), and radiation time (T), were observed for their contribution to the three responses, namely the total phenol content (TPC), the degree of depolymerization (DD), and the IC50 value of DPPH as an antioxidants activity. This study found that the best results were obtained at operating conditions FA, EtOH, and T 5 mL, 100 mL, 3 min in sequence, producing TPC, DD, and IC50 worth 4792,055 mg/ L, 23.650%, and 35.860 mg/L, respectively. The results were optimized using the response surface methodology with the Design Expert 11 program with the optimized result being FA, EtOH, and T 10 mL, 100 mL, 3 min consecutively and resulted in TPC, DD, and IC50 of 4987.12 mg/L, 26.451%, and 33.865 mg/L, respectively. The results of this study indicate that OPFEB is a source of lignin that has the potential to produce phenolic compounds, which are sources of renewable fine chemicals based on biomass. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenolysis systems of C-O bonds in furan ring, tetrahydrofuran ring and tetrahydropyran ring in biomass-derived cyclic compounds are reviewed. Furfural or its hydrogenation products (furfuryl alcohol and tetrahydrofurfuryl alcohol) have been frequently used as substrates for this type of reactions. Ring-opening of furfuryl alcohol over metal catalysts combined with basic components gives a mixture of 1,2-pentanediol, 1,5-pentanediol and other by-products. The selectivity much depends on catalysts and reaction conditions, and good 1,2-pentanediol selectivity can be obtained. For 1,5-pentanediol synthesis, more selective approaches have been reported such as Cu-zeolite catalysts for furfuryl alcohol hydrogenolysis in flow reactor and M-M'Ox-type (M: noble metal; M': transition metal) supported catalysts or Ni-LnOx (Ln: rare earth element) catalysts for tetrahydrofurfuryl alcohol hydrogenolysis. The metal catalysts and M-M'Ox-type catalysts can be applied to ring-opening hydrogenolysis of other furan- and tetrahydrofuran-based compounds, respectively. Among the products of ring-opening hydrogenolysis of biomass-derived compounds, 1,5-pentanediol seems to be the most important because of the potential use as a monomer. The recent progress and reported properties of polymers using 1,5-pentanediol as a monomer are also summarized. [ABSTRACT FROM AUTHOR]

Among the different polyoxometalate compounds, Keggin heteropolyacids have been extensively used as catalysts in several acid-catalyzed reactions, due to their strong strength of Bronsted acidity. These metal–oxygen clusters have a highly versatile structure that allows their conversion to derivatives, which are catalysts that are much more efficient than their precursors, with a greater catalytic activity in a plethora of reactions of industrial interest. Particularly, due to the inevitable exhaustion of fossil sources, reactions to valorize biomass have attracted significant attention, since it is a precious renewable raw material that can provide fine chemicals or fuels, minimizing our dependence on petroproducts. Biorefinery processes can produce platform molecules to achieve this goal. In this review, the recent advances achieved in the development of routes to converting biomass feedstocks to levulinic acid and furfural, which are valuable ingredients in biorefinery processes, using Keggin heteropolyacid catalysts were assessed. [ABSTRACT FROM AUTHOR]

Simultaneous conversion of CO2 and biomass into value-added chemicals through solar-driven catalysis holds tremendous importance for fostering a sustainable circular economy. Herein, plasmonic Bi quantum dots were immobilized on phosphoric acid modified attapulgite (P-ATP) nanorod using an in-situ reduction–deposition method, and were employed for photocatalytic reduction of CO2 coupled with oxidation of biomass-derived benzyl alcohol. Results revealed that Bi atoms successfully integrated into the basal structure of P-ATP, forming chemically coordinated Bi–O–Si bonds that served as efficient transportation channels for electrons. The incorporation of high-density monodispersed Bi quantum dots induced a surface plasmon resonance (SPR) effect, expanding the light absorption range into the near-infrared region. As a consequence, the photo-thermal transformation was significantly accelerated, leading to enhanced reaction kinetics. Notably, 50% Bi/P-ATP nanocomposite exhibited the highest plasmon-mediated photocatalytic CH4 generation (115.7 µmol·g−1·h−1) and CO generation (44.9 µmol·g−1·h−1), along with remarkable benzaldehyde generation rate of 79.5 µmol·g−1·h−1 in the photo-redox coupling system under solar light irradiation. The hydrogen protons released from the oxidation of benzyl alcohol facilitated the incorporation of more hydrogen protons into CO2 to form key CH3O− intermediates. This work demonstrates the synergistic solar-driven valorization of CO2 and biomass using natural mineral based catalyst. [ABSTRACT FROM AUTHOR]

The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals. [ABSTRACT FROM AUTHOR]

The catalytic isomerization of glucose to fructose plays a pivotal role in the application of biomass as a feedstock for chemicals. Herein, we propose a facile solid-state-grinding strategy to construct ZrO2/MgO mixed oxides, which offered an excellent fructose yield of over 34.55% and a high selectivity of 80.52% (80 °C, 2 h). The co-mingling of amphiphilic ZrO2 with MgO improved the unfavorable moderate/strongly basic site distribution on MgO, which can prohibit the side reactions during the reaction and enhance the fructose selectivity. Based on the catalyst characterizations, MgO was deposited on the ZrO2 surface by plugging the pores, and the addition of ZrO2 lessened the quantity of strongly basic sites of MgO. Additionally, the presence of ZrO2 largely enhanced the catalyst stability in comparison with pure MgO by recycling experiments. [ABSTRACT FROM AUTHOR]

The chemoselective hydrodeoxygenation of natural lignocellulosic materials plays a crucial role in converting biomass into value‐added chemicals. Yet their complex molecular structures often require multiple active sites synergy for effective activation and achieving high chemoselectivity. Herein, it is reported that a high‐entropy alloy (HEA) on high‐entropy oxide (HEO) hetero‐structured catalyst for highly active, chemoselective, and robust vanillin hydrodeoxygenation. The heterogenous HEA/HEO catalysts were prepared by thermal reduction of senary HEOs (NiZnCuFeAlZrOx), where exsolvable metals (e.g., Ni, Zn, Cu) in situ emerged and formed randomly dispersed HEA nanoparticles anchoring on the HEO matrix. This catalyst exhibits excellent catalytic performance: 100% conversion of vanillin and 95% selectivity toward high‐value 2‐methyl‐4 methoxy phenol at low temperature of 120 °C, which were attributed to the synergistic effect among HEO matrix (with abundant oxygen vacancies), anchored HEA nanoparticles (having excellent hydrogenolysis capability), and their intimate hetero‐interfaces (showing strong electron transferring effect). Therefore, our work reported the successful construction of HEA/HEO heterogeneous catalysts and their superior multifunctionality in biomass conversion, which could shed light on catalyst design for many important reactions that are complex and require multifunctional active sites. [ABSTRACT FROM AUTHOR]

Biomass is a renewable energy source abundantly available in nature. Their degradation by chemical or biological means produces various transition compounds. These transition compounds can be further transformed into valuable chemicals and biofuels that exhibit a wide range of applications and benefits. Recently, there has been a significant focus on this research area. Among the transition compounds, 5‐hydroxymethylfurfural (HMF), derived from the degradation of hexose, is an important biomass‐based platform compound that has hydroxymethyl and aldehyde functional groups in its molecular structure. This study reviews the recent progress in the transition metal‐catalysed conversion of HMF using Co and Mn to generate high‐value‐added downstream products. Furthermore, the active components, the carbon supporter, the reaction mechanism, the oxidants and the reaction conditions of the catalysts are discussed in detail. The oxidation of HMF deserves further research as an important and complete value‐added process for generating biomass‐based valuable chemicals. [ABSTRACT FROM AUTHOR]

Furfural is an industrial renewable platform chemical, which can be converted to useful furanics such as α-angelica lactone, carboxylic acids such as levulinic acid and valeric acid, or to higher carbon content products via condensation routes for producing drop-in fuel replacements and chemicals with diverse applications. These important conversion processes may be carried out in selective fashions, although they require adequate catalysts. They were successfully carried out using versatile, stable silica-wrapped niobium oxide nanostructured catalysts. For example, α-angelica lactone was converted in an integrated fashion to ethyl levulinate in 90% yield, and the esterification of levulinic and valeric acids gave ethyl levulinate in quantitative yield and ethyl valerate in 90% yield, respectively, at 140 °C. Catalytic, mechanistic and kinetic modelling studies shed light on the influence of the materials properties on the catalytic performances. These catalysts outperformed pure Nb2O5, as well as hydrothermally synthesized composites consisting of Nb2O5 nanoparticles embedded in a mesoporous siliceous matrix. [ABSTRACT FROM AUTHOR]

As we work to transition the modern society that is based on non‐renewable chemical feedstocks to a post‐modern society built around renewable sources of energy, fuels, and chemicals, there is a need to identify the renewable resources and processes for converting them to platform chemicals. Herein, we explore a strategy for utilizing the p‐hydroxybenzoate in biomass feedstocks (e. g. poplar and palm trees) and converting it into a portfolio of commodity chemicals. The targeted bio‐derived product in the first processing stage is p‐hydroxybenzamide produced from p‐hydroxybenzoate esters found in the plant. In the second stage a continuous reaction process converts the p‐hydroxybenzamide to p‐aminophenol via the Hofmann rearrangement and recovers the unreacted p‐hydroxybenzamide. In the third stage the p‐aminophenol can be acetylated to form paracetamol, which is readily isolated by liquid/liquid extraction at >95 % purity and an overall p‐hydroxybenzamide‐to‐paracetamol process yield of ~90 %. We explore how utilization of protecting groups alters the challenges in this process and expands the portfolio of possible products to include p‐(methoxymethoxy)aniline and N‐acetyl‐p‐(methoxymethoxy)aniline. These target compounds could become value‐added renewably‐sourced platform chemicals that could be used to produce biodegradable plastics, pigments, and pharmaceuticals. [ABSTRACT FROM AUTHOR]

The distance a solid biomass feedstock could be used to transport the feedstock when used as biobased fuel is critical information for transportation analysis. However, this information is not available. The break-even transportation distance (BTD) of various fuels from biomass feedstocks and fossil sources was analyzed for truck, rail, and ship transport modes based on bulk density, moisture content, and specific energy. Fourteen different biomass feedstocks, such as crop residues (e.g., corn stover), woody biomass (e.g., wood chips), including thermally pretreated (torrefied) and densified forms (pellets), cattle feedlot compost, and three standard fossil fuels, namely, coal, lignite, and diesel, were considered for BTD analysis and comparison. The BTD values were derived by comparing the energy content of biomass feedstocks with the energy expended in transporting the fuels through selected transportation modes. For ready reference, an alternative derivation of BTD equations and example calculations were also presented. Among the biomass feedstocks, torrefied pellets had the highest BTD (4.16 χ 10[sup 4],12.47 χ 10[sup 4], and 54.14 χ 10[sup 4] km), and cattle feedlot compost had the lowest BTD (1.29 χ 10[sup 4], 3.88 χ 10[sup 4], and 9.23 χ 10[sup 4] km), respectively, for truck, rail, and ship. Higher bulk density and higher specific energy of the biomass feedstocks increased the BTD for all modes of transport. Transport is most efficient when mass-limited. Biomass feedstock bulk densities where transportation becomes mass-limited are 223, 1,480, and 656 kg/m[sup 3] for truck, rail, and ship, respectively. Truck transport is typically mass-limited (payload limit restriction; increased BTD), whereas rail transport is entirely volume-limited (cargo space restriction; decreased BTD), and ship transport is mostly volume-limited for biomass feedstocks and mass-limited for densified biomass feedstocks. Ship transport is the most efficient, followed by rail and truck; on average for the materials (17) studied, rail is 3.1 times and ship is 9.2 times the truck's BTD. Based on the bulk density and higher specific energy of the biomass feedstocks, regardless of the refinery location, interstate truck transport of these feedstocks is not a limiting factor in the bio-refining process., with the studied biomass feedstock BTD per truckload representing between 0.89 and 2.88 times the US perimeter. [ABSTRACT FROM AUTHOR]

Direct conversion of inexpensive biomass into value-added chemicals via furanic platform molecules is highly attractive. In this work, we present a straightforward chemobiocatalytic route for glucose valorization into 2,5-bis(hydroxymethyl)furan (BHMF) in one pot, with no purification of the intermediate 5-hydroxymethylfurfural (HMF). Six candidate alcohol dehydrogenase (ADH) genes were located from Meyerozyma guilliermondii SC1103, based on comparative transcriptome analysis and real-time quantitative polymerase chain reaction. An ADH (MgADH1) was identified upon evaluation of catalytic performances of recombinant Saccharomyces cerevisiae harboring candidate ADHs in HMF reduction. Soluble expression of the enzyme in S. cerevisiae was greatly enhanced by its codon optimization, leading to improved HMF tolerance (up to 400 mM). In a fed-batch process, the desired product of approximately 473 mM (60.5 g/L) was produced within 30 h by recombinant S. cerevisiae_MgADH1. A chemobiocatalytic route toward BHMF was constructed by merging CaCl2-mediated isomerization and dehydration with biocatalytic reduction with an overall yield of approximately 42%, starting from glucose. This work may pave the way for green manufacture of valuable biobased chemicals. [ABSTRACT FROM AUTHOR]