Green Process for 5-(Chloromethyl)furfural Production from Biomass in Three-Constituent Deep Eutectic Solvent

Economical production of 5-hydroxymethylfurfural from sorghum juice as inexpensive feedstock in an acetone/water solvent system

5-Hydroxymethylfurfural (HMF), regarded as a vital link between bio-refining and petrochemical refining, demonstrates significant potential to produce sustainable chemicals, fuels, and materials. However, its reliance on food-grade sugars as feedstock limits economic feasibility. This study demonstrates that sweet sorghum juice, rich in fructose, glucose, and sucrose, is an ideal, low-cost raw material for HMF production. Using HCl as catalyst, fructose in sweet sorghum juice was fully converted, yielding over 90% HMF in 80/20 (v/v) acetone/ water solvent system, with more than 85% of glucose retained for recycling. When AlCl3 was used as catalyst, all sugars were efficiently converted, yielding over 70% HMF. Impurities in the pretreated juice did not impede sugar conversion but did partially neutralize the acidic catalyst. Techno-economic analysis revealed that utilizing sweet sorghum juice as feedstock produces HMF at a minimum selling price of $1909 per ton, a 39.6% reduction compared to fructose-based.

Recent advances in the chemical-catalytic approaches for the production of 5-(halomethyl)furfurals from cellulose and its derivatives: A review

5-Hydroxymethylfurfural (HMF) is recognized by the U.S. Department of Energy as a key platform chemical derived from renewable C6 sugars obtained from lignocellulosic biomass. Despite its importance, the economic utilization of HMF is limited by its hydrophilic properties and insufficient stability. In contrast, 5-(halomethyl)furfurals, which are hydrophobic analogs of HMF, demonstrate improved stability, making their extraction and purification easier while extending their shelf life. These compounds present an alternative opportunity for HMF in derivative chemistry. However, the literature on halogenated HMF derivatives is scattered and lacks a comprehensive review. This review aims to fill this gap by synthesizing current research, evaluating achievements and challenges, discussing pathways for the production of 5-(halomethyl)furfurals (XMF, where X = Cl, Br) from cellulose and its derivatives, detailing reaction mechanisms, and proposing improvements in catalytic systems. Future research may focus on the innovative and economically viable direct synthesis of these derivatives from biomass-derived sources for scale-up and commercialization.

Industrial Routes from Sugars and Biomass to CMF and Other 5-(Halomethyl)furfurals

The synthesis of 5-(halomethyl)furfurals (XMFs, X=F, Cl, Br, I), including 5-(chloromethyl)furfural (CMF), 5-(bromomethyl)furfural (BMF), 5-(iodomethyl)furfural (IMF), and 5-(fluoromethyl)furfural (FMF), from biomass represents a pivotal advancement in renewable chemistry and engineering. Harnessing waste biomass as a raw material offers a sustainable alternative to fossil-based resources, mitigating environmental degradation and addressing pressing energy needs. CMF and BMF, characterized by their enhanced stability over the hydroxyl analog, 5-(hydroxymethyl)furfural (HMF), exhibit promise as renewable building blocks for scale-up and commercialization. The surge in research interest, particularly from 2010 to 2024, reflects a growing recognition of XMFs' potential as novel platform chemicals. This review highlights the evolution of XMF synthesis methods, focusing on their transformation from saccharides and lignocellulosic biomass. Mechanistic insights and experimental setups are scrutinized for industrial feasibility and scalability, shedding light on technical challenges and avenues for further research. The analysis underscores the burgeoning significance of XMFs in the transition towards sustainable chemical production, emphasizing the importance of process optimization and mechanistic understanding for commercial deployment.

Catalytic Transformation of Carbohydrates into Renewable Organic Chemicals by Revering the Principles of Green Chemistry

Adherence to the principles of green chemistry in a biorefinery setting ensures energy efficiency, reduces the consumption of materials, simplifies reactor design, and rationalizes the process parameters for synthesizing affordable organic chemicals of desired functional efficacy and ingrained sustainability. The green chemistry metrics facilitate assessing the relative merits and demerits of alternative synthetic pathways for the targeted product(s). This work elaborates on how green chemistry has emerged as a transformative framework and inspired innovations toward the catalytic conversion of biomass-derived carbohydrates into fuels, chemicals, and synthetic polymers. Specific discussions have been incorporated on the judicious selection of feedstock, reaction parameters, reagents (stoichiometric or catalytic), and other synthetic auxiliaries to obtain the targeted product(s) in desired selectivity and yield. The prospects of a carbohydrate-centric biorefinery have been emphasized and research avenues have been proposed to eliminate the remaining roadblocks. The analyses presented in this review will steer to developing superior synthetic strategies and processes for envisaging a sustainable bioeconomy centered on biomass-derived carbohydrates.

Electrochemical Incorporation of Electrophiles into the Biomass-Derived Platform Molecule 5-(Chloromethyl)furfural

The 5-(chloromethyl)furfural (CMF) derivative ethyl 5-(chloromethyl)furan-2-carboxylate undergoes two-electron electrochemical reduction in a simple, undivided cell to give the corresponding furylogous enolate anion, which can either be quenched with carbon dioxide to give a 5-(carboxymethyl)furan-2-carboxylate or with hydrogen ion to give a 5-methylfuran-2-carboxylate, thereby expanding the derivative scope of CMF as a biobased platform molecule.

Thermochemical Conversion of Untreated and Pretreated Biomass for Efficient Production of Levoglucosenone and 5-Chloromethylfurfural in the Presence of an Acid Catalyst

Levoglucosenone (LGO) and 5-chloromethyl furfural (5-CMF) are two bio-based platform chemicals with applications in medicines, green solvents, fuels, and the polymer industry. This study demonstrates the one-step thermochemical conversion of raw and pretreated (delignified) biomass to highly-valuable two platform chemicals in a fluidized bed reactor. Hydrochloric acid gas is utilized to convert biomass thermochemically. The addition of hydrochloric acid gas facilitates the formation of LGO and CMF. Acid gas reacts with biomass to form 5-CMF, which acts as a catalyst to increase the concentration of LGO in the resulting bio-oil. The presence of higher cellulose content in delignified biomass significantly boosts the synthesis of both platform chemicals (LGO and CMF). GC-MS analysis was used to determine the chemical composition of bio-oil produced from thermal and thermochemical conversion of biomass. At 350 °C, the maximum concentration of LGO (27.70 mg/mL of bio-oil) was achieved, whereas at 400 °C, the highest concentration of CMF (19.24 mg/mL of bio-oil) was obtained from hardwood-delignified biomass. The findings suggest that 350 °C is the optimal temperature for producing LGO and 400 °C is optimal for producing CMF from delignified biomass. The secondary cracking process is accelerated by temperatures over 400 °C, resulting in a low concentration of the target platform chemicals. This work reveals the simultaneous generation of LGO and CMF, two high-value commercially relevant biobased compounds.

Unraveling the unique butyrate re-assimilation mechanism of Clostridium sp. strain WK and the application of butanol production from red seaweed Gelidium amansii through a distinct acidolytic pretreatment

Exploration of the algae-derived biobutanol synthesis has become one of the hotspots due to its highly cost-effective and environment-friendly features. In this study, a solventogenic strain Clostridium sp. strain WK produced 13.96 g/L butanol with a maximal yield of 0.41 g/g from glucose in the presence of 24 g/L butyrate. Transcriptional analysis indicated that the acid re-assimilation of this strain was predominantly regulated by genes buk-ptb rather than ctfAB, explaining its special phenotypes including high butyrate tolerance and the pH-independent fermentation. In addition, a butyric acid-mediated hydrolytic system was established for the first time to release a maximal yield of 0.35 g/g reducing sugars from the red algal biomass (Gelidium amansii). Moreover, 4.48 g/L of butanol was finally achieved with a significant enhancement by 29.9 folds. This work reveals an unconventional metabolic pathway for butanol synthesis in strain WK, and demonstrates the feasibility to develop renewable biofuels from marine resources.

Preparation of Furfural From Xylose Catalyzed by Diimidazole Hexafluorophosphate in Microwave

In this work, functionalized alkyl imidazolium hexafluorophosphate ILs were synthesized and characterized; then, they were applied in the conversion of xylose to furfural under the microwave method. The results showed that when C_nMF was used as a catalyst, an acidic environment was provided to promote the formation of furfural. In addition, the heating method, the solvent, and the different structures of cations in the ionic liquid influenced their catalytic activity. In an aqueous solution, the yield of furfural obtained using the microwave method was better than that of the conventional heating method, and the catalytic activity of diimidazole hexafluorophosphate was better than that of monoimidazole. Meanwhile, for the diimidazole hexafluorophosphate, the change of the carbon chain length between the imidazole rings also slightly influenced the yield. Finally, the optimal yield of 49.76% was obtained at 205°C for 8 min using 3,3′-methylenebis(1-methyl-1H-imidazol-3-ium), C₁MF, as a catalyst. Mechanistic studies suggested that the catalytic activity of C₁MF was mainly due to the combined effect of POF_n (OH)_3-n and imidazole ring. Without a doubt, the catalytic activity of C₁MF was still available after five cycles, which not only showed its excellent catalytic activity in catalyzing the xylose to prepare the biomass platform compound furfural but also could promote the application of functionalized ionic liquids.