Catalytic etherification of 5-hydroxymethylfurfural into 5-ethoxymethyfurfural over sulfated bimetallic SO42−/Al-Zr/KIT-6, a Lewis/Brønsted acid hybrid catalyst

Mesoporous SO42- / kit-6-catalyzed hydrocracking of waste chicken oil

In this study, we studied the hydrocracking of waste chicken oil (WCO) catalyzed by mesoporous SO42-/KIT-6. The study included WCO extraction, SO42-/KIT-6 catalyst synthesis, hydrocracking, and catalytic characterization. XRD patterns revealed intense peaks in the low-angle region, with shoulder peaks showing an increase in sulphate loading from 10% to 30%. The BET-specific surface area for the pure KIT-6 supports measured at 1003 m2/g, indicative of a well-defined mesoporous structure. Thermogravimetric analysis (TGA) showed a two-stage weight loss, attributed to the elimination of hydrated water (about 200 °C) and decomposition of sulphate ions (400-450 °C). SEM analysis highlighted the surface morphology of the active SK-2 catalyst. Hydrocatalytic and catalytic cracking reactions were performed, and about 99.8% conversion was achieved with 20 mL/H H2 flow, whereas higher production of bioliquids was observed at a flow of 15 mL/h. The hydrocracking mechanism was also studied to understand the formation of lower hydrocarbons. GC analyses of simulated distilled gasoline, kerosene, and diesel showed diverse hydrocarbon compositions. For engine testing, non-hydrocracked fuel rose to 28 kW at 3000 rpm and declined to 21 kW at 3500 rpm. Emission analysis revealed decreasing trends in NOX emissions of hydrogen-rich blends, with values of 65 ppm, 54 ppm, and 48 ppm for petrol, NHBL, and HBL, respectively. Similarly, SO2 emissions reduced from petrol to NHBL and HBL at 910 ppm, 800 ppm, and 600 ppm, respectively, suggesting reduced environmental impact. CO emissions exhibited a substantial reduction in NHBL (0.90%) and HBL (0.54%) compared to petrol (2.70%), emphasizing the cleaner combustion characteristics. Our results provide a comprehensive exploration of waste chicken oil hydrocracking, emphasizing catalyst synthesis, fuel characterization, engine performance, and environmental impact, thereby contributing valuable insights to the field of sustainable bioenergy.

5-Hydroxymethylfurfural and its Downstream Chemicals: A Review of Catalytic Routes

Biomass assumes an increasingly vital role in the realm of renewable energy and sustainable development due to its abundant availability, renewability, and minimal environmental impact. Within this context, 5-hydroxymethylfurfural (HMF), derived from sugar dehydration, stands out as a critical bio-derived product. It serves as a pivotal multifunctional platform compound, integral in synthesizing various vital chemicals, including furan-based polymers, fine chemicals, and biofuels. The high reactivity of HMF, attributed to its highly active aldehyde, hydroxyl, and furan ring, underscores the challenge of selectively regulating its conversion to obtain the desired products. This review highlights the research progress on efficient catalytic systems for HMF synthesis, oxidation, reduction, and etherification. Additionally, it outlines the techno-economic analysis (TEA) and prospective research directions for the production of furan-based chemicals. Despite significant progress in catalysis research, and certain process routes demonstrating substantial economics, with key indicators surpassing petroleum-based products, a gap persists between fundamental research and large-scale industrialization. This is due to the lack of comprehensive engineering research on bio-based chemicals, making the commercialization process a distant goal. These findings provide valuable insights for further development of this field.

Synthesis of 5-(Hydroxymethyl)furfural Monoesters and Alcohols as Fuel Additives toward Their Performance and Combustion Characteristics in Compression Ignition Engines

The synthesis of 5-(hydroxymethyl)furfural (HMF) and conversion to the corresponding HMF-monoesters upon certain treatment are presented with their properties that are validated in a diesel engine. With a collection of fatty acids (C8-C18) using cyanuric acid as a catalyst under mild reaction conditions, the subsequent reduction of the HMF-monoesters with NaBH4 produced the corresponding alcohols. After purification, both HMF-monoesters and their alcohol derivatives were determined for their solubility, cetane index, heat of combustion, viscosity, and specific gravity. HMF-Capric (1-C10), HMF-Oleic (1-C18:1), HMF-Caprylic-OH (2-C8), and HMF-Oleic-OH (2-C18:1) were soluble in a neat diesel fuel. The observed highest cetane index and heat of combustion of 1-C10 and 1-C18:1 were evaluated for combustion characteristics in a single-cylinder compression ignition engine. The diesel fuel containing 3% 1-C10 displayed comparable properties during burning in terms of thermal efficiency, cylinder pressure, and heat release rate with respect to the neat diesel fuel (D100) for all usage engine speeds. In general, all tested fuels initiated their burning onset with a similar ignition delay period. The 3% 1-C10-blended diesel fuel emitted slightly higher smoke opacity but an equivalent nitric oxide level compared to those of D100. The HMF-Capric (1-C10) synthesized in this study represents a promising additive for diesel fuel. Blended fuel lubricity and other unregulated emissions upon broader engine test cycles are suggested to be accomplished in future work.

Catalytic Upgrading of Lignocellulosic Biomass Sugars Toward Biofuel 5-Ethoxymethylfurfural

The conversion of biomass into high-value chemicals through biorefineries is a requirement for sustainable development. Lignocellulosic biomass (LCB) contains polysaccharides and aromatic polymers and is one of the important raw materials for biorefineries. Hexose and pentose sugars can be obtained from LCB by effective pretreatment methods, and further converted into high-value chemicals and biofuels, such as 5-hydroxymethylfurfural (HMF), levulinic acid (LA), γ-valerolactone (GVL), ethyl levulinate (EL), and 5-ethoxymethylfurfural (EMF). Among these biofuels, EMF has a high cetane number and superior oxidation stability. This mini-review summarizes the mechanism of several important processes of EMF production from LCB-derived sugars and the research progress of acid catalysts used in this reaction in recent years. The influence of the properties and structures of mono- and bi-functional acid catalysts on the selectivity of EMF from glucose were discussed, and the effect of reaction conditions on the yield of EMF was also introduced.

Catalytic Synthesis of the Biofuel 5-Ethoxymethylfurfural (EMF) from Biomass Sugars

A new generation of bioplatform molecule 5-ethoxymethylfurfural (EMF) has excellent energy density and combustion performance, which makes it a potential fuel additive. This article reviews the factors that affect the production of EMF from different feedstocks, including platform compounds, monosaccharides, polysaccharides, and raw lignocellulosic biomass. Focus is placed on discussing the catalytic efficiency with pros and cons of different acid catalysts, including homogeneous catalysts (i.e., liquid acids and metal salts), heterogeneous catalysts (i.e., zeolites, heteropolyacid-based hybrids, and SO3H-based catalysts), ionic liquids, mixed acid catalysts, and deep eutectic solvents (DESs). Except for the commonly used ethanol solvent, this review also summarizes the influence of the cosolvent system (e.g., ethanol/dimethylsulfoxide (DMSO), ethanol/tetrahydrofuran (THF), and ethanol/γ-valerolactone (GVL)) on the EMF yield.