Transformation Of Biomass Research Articles

Catalytic Transformation of Biomass into Sustainable Carbocycles: Recent Advances, Prospects, and Challenges.

Organic compounds bearing one or more carbocycles in their molecular structure have a discernible presence in all major classes of organic products of industrial significance. However, sourcing carbocyclic compounds from exhaustible, anthropogenic carbon (e. g., petroleum) raises serious concerns about sustainability in the chemical industries. This review discusses recent advances in the renewable synthesis of carbocyclic compounds from biomass components following catalytic pathways. The mechanistic insights, process optimizations, green metrics, and alternative synthetic strategies of carbocyclic compounds have been detailed. Moreover, the renewable syntheses of carbocycles have been assessed against their existing synthetic routes from petroleum for better perspectives on their sustainability and technological preparedness. This work will assist the researchers in acquiring updated information on the sustainable synthesis of carbocyclic compounds from various biomass components, comprehending the research gaps, and developing superior synthetic processes for their commercial production.

Small Molecules Effective for Conversion of Lignocellulosic Biomass to Furfural and Its Derivatives

This review summarizes recent applications of small organic and inorganic molecules as catalysts or solvents (chemical hands and scissors) in the production of furfural (FA), 5-(hydroxymethyl)furfural (HMF), and 5-(chloromethyl)furfural (CMF). The possible transformation of lignocellulosic biomass into a one-pot configuration and two-step technique based on the preliminary separation of hemicellulose, lignin and cellulose with the subsequent hydrolysis of separated polysaccharides is compared and discussed. Interestingly, these rather simple and cheap molecules are catalytically active and enable a high rate of conversion of polysaccharides into furfural and its derivatives. Usually, elevated pressure and reaction temperatures above 150 °C are necessary for effective hydrolysis and dehydration of in situ formed monosaccharides; nevertheless, ionic liquids or deep eutectic solvents enable a significant decrease in the reaction temperature and performance of the discussed process at ambient pressure.

Efficient Production of Platform Chemicals from Lignocellulosic Biomass by Using Nanocatalysts: A Review

This paper discusses significant advancements in using lignocellulosic biomass for the sustainable production of biofuels and chemicals. As fossil-based resources decline and environmental concerns rise, the paper emphasizes the role of integrated biorefineries in producing renewable liquid fuels and high-value chemicals from biomass. It highlights exploring various green pathways for biomass conversion, with a particular focus on nanocatalysis. Due to their large surface area-to-volume ratio, nanocatalysts provide enhanced catalytic activity and efficiency in biomass transformation processes. The review delves into the synthesis of value-added and furfural platform chemicals alongside the hydrogenolysis of 5-hydroxymethylfurfural (5-HMF) into biofuels like 2,5-dimethylfuran (DMF) and 2,5-dimethyltetrahydrofuran (DMTHF). The paper ultimately underscores the importance of nanotechnology in achieving high yield and selectivity in the biomass conversion process, positioning it as a promising approach for future sustainable energy and chemical production.

Sustainable production of organic acids from chitin biomass catalyzed by Keggin-type heteropolyacid under hydrothermal condition

The “shell biorefinery,” which valorizes the shell waste chitin into fine chemicals, has developed rapidly in recent years. Herein, we present a novel base-free heteropolyacid-catalyzed oxidation method for the transformation of chitin biomass into organic acid. After a series of optimization experiments, a 5.93 % yield of formic acid and 25.09 % yield of acetic acid were achieved in the presence of 0.5 equivalent of Mo–V–P heteropolyacids (H4PMo11VO40·2H2O) and air at 180 °C under hydrothermal conditions for 4 h. Meanwhile, we have demonstrated that the Keggin-type heteropolyacid catalysts are capable of efficiently converting microcrystalline chitin into organic acids. The synthesized heteropolyacids are well characterized with FT-IR, XRD, ICP-AES, and TGA. The possible reaction pathway was speculated accordingly. This method offers several advantages, including readily available raw materials, simple operation, and relatively higher yield.

Promoting role of Ru species on Ir-Fe/BN catalyst in 1,2-diols hydrogenolysis to secondary alcohols

Noble metal-based-bimetallic catalysts have been highly investigated and applied in wide applications including biomass transformation via regioselective C−O hydrogenolysis while further modification especially with noble metal is highly promising yet still under investigation. Herein, Ru was found as an effective modifier among the screened noble metals (Ru, Pt, Rh, Pd, Au, and Ag) for Ir-Fe/BN (Ir = 5 wt%, Fe/Ir = 0.25) catalyst in terminal C−O hydrogenolysis of 1,2-butanediol (1,2-BuD) to 2-butanol (2-BuOH). Only trace amount of Ru (up to 0.5 wt%) was effective in terms of high 2-BuOH selectivity (> 60%) and activity (about twice). Larger amount of Ru species (3 wt%) highly enhanced the activity but gave low selectivity to 2-BuOH with by-products of terminal C−C bond scission. Optimized catalyst (Ru(0.5)-Ir-Fe/BN) was reusable at least 4 times and gave moderate 2-BuOH yield (47%) in hydrogenolysis of 1,2-BuD. The promoting effect of Ru addition (0.5 wt%) to Ir-Fe/BN on hydrogenolysis of various alcohols was also confirmed. Combining catalytic tests with various characterizations, the promotion mechanism of Ru species in trimetallic catalysts was clarified. The Ru species in Ru(0.5)-Ir-Fe/BN form alloy with Ir and are enriched at the interface with BN surface, and direct interaction between Ru and Fe was not necessary in Ru-Ir-Fe alloy. The interface of Ir and Fe on the surface of Ir-Fe alloy may work as active sites for 1,2-diols to secondary alcohols via direct C−O hydrogenolysis, in which Ru-modified Ir activates H2 to form hydride-like species. The activity of Ru species in C−C bond cleavage was highly suppressed due to the direct interaction with Ir species and less exposed to substrate. Larger loading amount of Ru species (3 wt%) led to the formation Ru-rich trimetallic alloy, which further works as active sites for C−C bond scission.

Characterization of bio-crude produced by graphene carbon tetranitrate catalyzed hydrothermal liquefaction and ultrasonication of Ulva prolifera mixed Chicken waste

<p style="text-align:justify;"><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">The utilization of macroalgae, specifically </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, for the manufacture of bio-crude demonstrates great potential as a viable alternative to conventional fossil fuels. This is mostly owing to its abundant availability and renewable characteristics, making it an optimal choice for bio-oil production. This study examined the synthesis of bio-crude through the Hydrothermal Liquefaction (HTL) method. The combination of Ultra-sonicated </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, Chicken Waste, and water facilitated the transformation of the moist biomass into Bio-crude. The study also examined the influence of process parameters, including the optimal operational temperature, retention time, and feedstock mixing ratio (275 <sup>o</sup>C, 30 minutes, and 1:4 ratio) for the graphene-C<sub>3</sub>N<sub>4 </sub>catalyst, KOH. The study's findings verified that a significant amount of bio-oil, specifically 23.5wt.% based on dry weight measurements, was successfully produced. The bio-oil mostly consists of alcohols, esters, phenols, ketones, and acidic chemicals. Furthermore, the bio-oil exhibited a significant heating value of 38.15 MJ/kg, which can be attributed to the presence of carboxylic acid groups and aliphatic hydrocarbons. Furthermore, the carbon content in the bio-oil was found to be double that of the macroalgae used as feedstock. Additionally, the heating value of the bio-oil was shown to be 2.5 times greater than that of the macroalgae. Hydrothermal liquefaction may be used to efficiently create bio-oil from </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, a third-generation fuel that has great potential as an environmentally benign and sustainable energy source.</span></p>

Nickel doped enhanced LaFeO3 catalytic cracking of tar for hydrogen production

The transformation of biomass into green energy was pivotal for sustainable development, yet the efficient conversion of biomass-derived tar into hydrogen-rich syngas remained a significant challenge. This study addressed the catalytic demand for hydrogen production from tar, focusing on the development of LaNixFe1-xO3 perovskites as catalysts. A series of LaNixFe1-xO3 perovskites with varying nickel doping levels (x=0, 0.25, 0.5, 0.75, 1) were synthesized to evaluate their catalytic performance in converting toluene, a representative tar component, into hydrogen. The LaNi0.5Fe0.5O3 catalyst demonstrated the highest hydrogen yield (14.5L/6h) and volume percentage (82.9V/V%), highlighting the optimal nickel doping level for enhancing hydrogen production. The hydrogen production performance of LaNixFe1-xO3 was significantly affected by nickel doping. In particular, a small amount of nickel doping can significantly enhance the hydrogen production capacity of LaFeO3 and maintain good reaction stability. The enhanced performance was attributed to the high oxygen storage capacity of perovskite, which facilitated the removal of surface carbon and promotes the methanation reaction. Notably, the total content of defect oxygen and surface adsorbed oxygen/hydroxyl groups significantly impacted the hydrogen production efficiency. These findings indicated that LaNi0.5Fe0.5O3 was an effective catalyst for converting biomass-derived tar into hydrogen-rich syngas, offering a promising solution to the catalytic demand in the hydrogen production system.

Cellulose extraction from Cladophora rupestris for extraction of nanomaterials

Abstract Cellulose from macroalgae is potential for the extraction of nanomaterials due to its availability and its great fraction in the biomass. Cladophora rupestris is a macroalgae and is a good material to which a cellulose may be extracted. The said macroalgae has no value-added products or uses yet. It has a lignocellulosic profile of: alpha-cellulose, 33.43 %; hemicellulose, 15.48%; holocellulose, 48.93; acid soluble lignin, 2.22%; acid insoluble lignin, 22.33%, extractives, 5.67% and total ash, 39.65%. Identifying the best method and conditions for the extraction of cellulose from the said material is a challenge that needs to be addressed. The process for the cellulose extraction considered variations on drying (oven, air, and sun drying), defatting (using solvents: methanol and hexane; and extraction time: 8 hrs and 4 days), solvent drying (oven and air drying), alkaline pre-treatment (0.1, 0.5, and 1M NaOH), fixed conditions on bleaching, bleached biomass oven drying. The biomass weight losses were monitored for some steps, attributing this on the removal of the lignin and extractives. The lignocellulosic profile of the crude cellulose extracted from the macroalgae using the best conditions was determined indicating an increased fraction of the cellulose components in the biomass and a transformation of the rigid biomass into a soft and paper-like texture. The functional groups present on the cellulose was determined. The extracted cellulose was used to produced cellulose nanofibril (CNF) with fiber diameter of the CNF ranges on 14.29 – 37.50 nm and crystallinity index of 92.48%. Attempts were done on extraction of cellulose nanocrystal (CNC) utilizing microwave-assisted acid hydrolysis (MAAH) and semi-batch acid hydrolysis (SBAH); and variation on the acid used (sulfuric acid, and oxalic acid), concentration of the acid, and the temperature conditions.

Полициклические ароматические углеводороды в снежном покрове заповедных территорий Республики Коми

We studied the content of polycyclic aromatic hydrocarbons (PAHs) in snow cover of protected northern areas Komi Republic. PAHs in snow were determined by high-performance liquid chromatography. Insignificant PAHs levels in the range of 30–46 ng/L were found in the snow cover of protected areas. Naphthalene and phenanthrene were the main PAHs in the snow cover. Light PAHs were mainly present in dissolved form. The heavy PAHs in the snow cover were present in trace amounts and accumulated on the aerosol particles. Low toxicological activity was observed in all tested samples. The natural, non-pyrogenic origin of the PAHs was established on the basis of their diagnostic ratios. This may be an indication that PAHs enter the snowpack mainly through transformation of plant biomass and global air mass transport. The PCA showed a significant similarity of the PAH composition of all investigated sites. All the above facts allow relating the studied areas to background. It was found that the level of low-volatility PAHs entering the protected areas in 2023 is the same as the level of entering the background areas of the taiga zone of the Komi Republic in 2005–2007. The highest content of heavy PAHs and toxicological activity was found in the snow cover near the Yaksha settlement in the Pechoro-Ilychsky Reserve. Aerosol polyarenes were the main contributors to PAH toxicity. In comparison with low-intensity roads near the “Paraskiny Lakes” Reserve, it is shown that furnace heating has a greater effect on the PAHs composition in the snow cover.

Inverse ceria-nickel catalyst for enhanced C-O bond hydrogenolysis of biomass and polyether.

Regulating interfacial electronic structure of oxide-metal composite catalyst for the selective transformation of biomass or plastic waste into high-value chemicals through specific C-O bond scission is still challenging due to the presence of multiple reducible bonds and low catalytic activity. Herein, we find that the inverse catalyst of 4CeOx/Ni can efficiently transform various lignocellulose derivatives and polyether into the corresponding value-added hydroxyl-containing chemicals with activity enhancement (up to 36.5-fold increase in rate) compared to the conventional metal/oxide supported catalyst. In situ experiments and theoretical calculations reveal the electron-rich interfacial Ce and Ni species are responsible for the selective adsorption of C-O bond and efficient generation of Hδ- species, respectively, which synergistic facilitate cleavage of C-O bond and subsequent hydrogenation. This work advances the fundamental understanding of interfacial electronic interaction over inverse catalyst and provides a promising catalyst design strategy for efficient transformation of C-O bond.

Enhanced hydrothermal stability by a semi-embedded structure: An efficient Ru catalyst for levulinic acid conversion in the aqueous phase

Catalyst stability is believed to be one of the greatest challenges faced for the supported metal catalysts in the catalytic conversion of biomass and its derivatives because many biomass transformations are conducted in the aqueous phase. In this work, we report a simple yet efficient coating-impregnation-pyrolysis (CIP) strategy to fabricate Al2O3 supported Ru catalyst (Ru-Al2O3@CN) with Ru NPs (nanoparticles) semi-embedded into N-doped carbon (CN) layer for the efficient hydrogenation of levulinic acid (LA) to γ-valerolactone in the aqueous phase. Benefit from the special structure of Ru-Al2O3@CN catalyst, it possesses both high catalytic activity and stability, giving a TOF of 28,099 h-1 for LA hydrogenation at 120 °C and 2 MPa H2, which is superior to the most of reported Ru-based catalysts. More importantly, compared with conventional impregnated Ru/Al2O3 catalyst, the Ru-Al2O3@CN catalyst exhibits a remarkably improved hydrothermal stability. Based on series of catalyst characterizations and control experiments, it was found that the presence of CN can weak the interaction between Ru and Al2O3, as well as protect the Al2O3 and Ru NPs from hydrolysis and aggregation, respectively. We anticipate that such a novel strategy may provide some valuable insights into the synthesis of oxides-supported metal catalyst with high hydrothermal stability.

TiO2 promoted alcohol dehydrations on the Wells-Dawson type heteropolyacids

The catalytic dehydrations of methanol and n-butanol on strongly acidic solids have been tested in two types of microreactors in the gas phase between 80 – 240 ºC. For the methanol transformation to dimethyl ether, the conversion was evaluated in situ with an innovative use of the FTIR spectroscopy in batch microreactor. The same catalysts were used for the conversion of n-butanol to butenes and n-butyl-ether under similar conditions, determined using a flow microreactor with the conventional gas chromatography downstream analysis. The catalysts included the Wells-Dawson type heteropolyacids, H6P2W18O62 and H6P2Mo18O62, supported on TiO2 and/or BN. The activity orders obtained in those methods were compared to that obtained by the ammonia sorption using the gas-flow through microcalorimeter at 150 ºC. The significant effect of TiO2 and BN supports in the methanol and butanol dehydrations makes the TiO2 and BN-supported Well-Dawson type heteropolyacids potentially relevant for industrial transformations of biomass derived feedstock.

Hybrid NenG/ZSM‐5 Towards Highly Selective and Efficient Photocatalysis for Generation of Leucodopaminechrome and Gluconic Acid Under Solar Light

AbstractGlucose, an abundant and renewable form of biomass, has garnered significant attention in research for its conversion into high‐value chemicals such as gluconic acid. Traditional methods for biomass transformation typically involve high energy input, elevated temperature, pressure, and costly systems. In contrast, photocatalysis emerges as a promising approach to produce organic molecules under mild conditions, harnessing energy from natural sunlight or lamps. This study presents the nitrogen‐enriched graphene with zeolite second Mobil–5 (NenG/ZSM‐5) photocatalyst, evaluated for generating high‐value chemicals (gluconic acid and leucodopaminechrome) under solar light irradiation. The NenG/ZSM‐5 photocatalyst, synthesized from nitrogen‐doped graphene and ZSM‐5, successfully converted dopamine into leucodopaminechrome (71.54 %) — a critical step in dopamine regeneration and transformed glucose into gluconic acid (85 %). The addition of ZSM‐5 to NenG provided stability and enhanced product selectivity. The outstanding performance of the NenG/ZSM‐5 photocatalyst can be attributed to its heightened solar light harvesting potential, appropriate energy band gap, and uniformly arranged π‐electron channels. This research focuses on solar conversion of glucose to gluconic acid and dopamine regeneration, with potential for further exploration in the research domain.

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.

Direct transformation of rice straw to electricity and hydrogen by a single yeast strain: Performance and mechanism

Lignocellulosic waste is one of the most abundant renewable energy sources. However, pretreatment or complex microbial consortia are usually required for the biological transformation into energy products. This study demonstrates the direct transformation of raw rice straw biomass into electricity and hydrogen without any pretreatment by employing a single yeast strain, Cystobasidium slooffiae JSUX1, in microbial fuel cells (MFCs). The yeast-MFCs exhibit a maximum power density of 28.56 ± 2.54 mW/m2 with simultaneous production of hydrogen gas (4.9 ± 0.52 L/m3) from raw straw. Further analysis reveals that enzymes secreted by the yeast strain degraded rice straw into sugars or organic acids, serving as fuel for electricity and hydrogen production. In addition, humic acid (HA) and Fe-HA derived from biomass consumption serve as electron mediators for extracellular electron transfer (EET) in MFCs. This study demonstrates the power of the yeast strain for renewable energy recovery from straw, diversifying the toolbox for the lignocellulose industry.

A Combination of Transcriptome and Enzyme Activity Analysis Unveils Key Genes and Patterns of Corncob Lignocellulose Degradation by Auricularia heimuer under Cultivation Conditions.

The cultivation of Auricularia heimuer, a species of edible mushroom, heavily relies on the availability of wood resources serving as substrate for the growth of the species. To ensure the sustainable development of the A. heimuer industry and optimize the utilization of corncob as a substrate, this study sought to investigate the potential use of corncob as a substrate for the cultivation of A. heimuer. The purpose of this study was to explore the utilization of corncob lignocellulose by A. heimuer at the mycelium, primordium, and fruiting stages, by specifically examining the expression profiles of both carbohydrate-active enzymes (CAZymes) and the transcriptome of differentially expressed genes (DEGs) relevant to corncob biomass degradation. The results revealed 10,979, 10,630, and 11,061 DEGs at the mycelium, primordium, and fruiting stages, respectively, while 639 DGEs were identified as carbohydrate-active enzymes. Of particular interest were 46 differentially expressed CAZymes genes that were associated directly with lignocellulose degradation. Furthermore, the study found that A. heimuer exhibited adaptive changes that enabled it to effectively utilize the cellulose present in the corncob. These changes were observed primarily at the primordium and fruiting stages. Key genes involved in lignocellulose degradation were also identified, including g6952, g8349, g12487, and g2976 at the mycelium stage, g5775, g2857, g3018, and g11016 at the primordium stage, and g10290, g2857, g12385, g7656, and g8953 at the fruiting stage. This study found that lytic polysaccharide monooxygenase (LPMO) played a crucial role in the degradation of corncob cellulose, further highlighting the complexity of the molecular mechanisms involved in the degradation of lignocellulose biomass by A. heimuer. The study sheds light on the molecular mechanisms underlying the ability of A. heimuer to degrade corncob biomass, with implications for the efficient utilization of lignocellulose resources. The findings from this study may facilitate the development of innovative biotechnologies for the transformation of corncob biomass into useful products.

Green pathways for biomass transformation: A holistic evaluation of deep eutectic solvents (DESs) through life cycle and techno-economic assessment

The utilization of renewable biomass resources to manufacture biofuels, chemicals, and materials has garnered considerable attention. Deep eutectic solvents (DESs) have surfaced as a promising instrument within the realm of biomass conversion, owing to their distinctive attributes such as biodegradability, negligible toxicity, easier fabrication, liquid-phase stability and renewability as opposed to ionic liquids (ILs). Research into DESs, particularly those derived from natural sources, is expanding to advance affordable and sustainable biomass conversion. However, the bottlenecks of DES are its limited solubility for certain biomass constituents, cost and availability. To overcome these hurdles, ongoing research and technological innovations strive to tap into the complete potential of DESs in biomass conversion. This review underscores the importance of evaluating DESs' eco-friendly potential comprehensively, encompassing ecological, financial, and technological standpoints which aims to illuminate how DESs can effectively contribute to sustainable biomass utilization, fostering an environmentally conscious circular bio-based economy.

Catalytic Biomass Transformation to Hydrocarbons under Supercritical Conditions over Nickel Supported on Schungite

Liquid fuel production from biomass-derived molecules has received great attention due to the diminished fossil fuel reserves, growing energy demand, and the necessity of CO2 emission reduction. The deoxygenation of oils and fatty acids is a promising process to obtain “green” diesel. Herein, we report the results of the study of the deoxygenation of stearic acid to alkanes as a model reaction. Series of Ni-supported on schungite were obtained by precipitation in subcritical water (hydrothermal deposition) and for comparison via wetness impregnation followed, in both cases, by calcination at 500 °C and a reduction in H2 at 300 °C. The catalyst obtained via hydrothermal synthesis showed a three-fold higher specific surface area with a four-fold higher active phase dispersion compared to the catalysts synthesized via conventional impregnation. The catalysts were tested in stearic acid deoxygenation in supercritical n-hexane as the solvent. Under optimized process conditions (temperature of 280 °C, hydrogen partial pressure of 1.5 MPa, and 13.2 mol of stearic acid per mol of Ni), a close to 100% yield of C10–C18 alkanes, containing over 70 wt.% of targeted n-heptadecane, was obtained after 60 min of reaction.

High-efficient microwave-assisted conversion of fructose to 5-hydroxymethylfurfural over rice straw-derived sulfonated porous carbonaceous catalyst

5-Hydroxymethylfurfural (HMF) has emerged as a pivotal platform chemical derived from biomass, attracting considerable attention for its renewable applications. In this study, sulfonated rice straw biochar (RSBC-SA) catalysts were developed and employed for microwave-assisted catalytic conversion of fructose to HMF. The RSBC-SA catalysts, synthesized by pyrolyzing rice straw biomass at different temperatures and subsequent functionalization with sulfonic acid groups, were characterized using X-ray photoelectron spectroscopy (XPS), elemental analysis, temperature programmed desorption (TPD) and Fourier-transform infrared spectroscopy (FT-IR). A comparative analysis of catalytic performance between microwave irradiation and conventional oil bath heating revealed a substantial enhancement in efficiency with the former. Notably, the 700 ℃ pyrolyzed RSBC-SA catalyst demonstrated the highest HMF yield of 92.6 % within just 5 min of reaction time under a microwavehydrothermal condition, surpassing the conventional oil bath heating method. In addition, moderate to high yields of HMF were achieved from different carbohydrates in our developed microwave reaction system, demonstrating significant catalytic activity. This superior catalytic effect under microwave irradiation can be attributed to the responsive dipole polarization of sulfonic acid groups, selective heating of the RSBC carrier via microwave absorption, and synergistic interactions among these factors. Overall, this study highlights the innovative use of agricultural waste and introduces a new method for creating microwave-responsive catalysts with biochar. This strategy enables efficient fructose conversion to HMF, promotes sustainable biomass transformation, and offers value-added uses for agricultural residues in chemical production.

Advanced Thermochemical and Biochemical Processes for Biomass Transformation To Biofuels and Biochemicals

Advanced Thermochemical and Biochemical Processes for Biomass Transformation To Biofuels and Biochemicals