A Systematic Study of Metal Triflates in Catalytic Transformations of Glucose in Water and Methanol: Identifying the Interplay of Brønsted and Lewis Acidity

Directional methanolysis of kitchen waste for the co-production of methyl levulinate and fatty acid methyl esters: Catalytic strategy and machine learning modeling

To add value to ordinary kitchen waste, heterogeneous acid-base catalytic methanolysis was conducted to produce high-value liquid biofuels, methyl levulinate (ML) and fatty acid methyl esters (FAMEs). Yields of 53.3 % ML and 98.5 % FAME were achieved by methanolysis of kitchen waste under the co-catalysis of carbon-silica composite (C/Si-SO₃H) and zirconium modified ultrastable Y zeolite (Zr/USY). These target products can be easily recovered from the methanolic phase and can be purified at the end of the reaction. The collaborative combination of C/Si-SO₃H and Zr/USY exhibited higher activity than their commercial counterpart. This strategy can be applied to differently composed kitchen waste and kitchen waste with different water content. Product yields were predicted using an artificial neural network method, and the relative importance of the influencing factors was investigated by the random forest method. The systematic insight gained from this work supports the value-added utilization of kitchen waste.

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

5-(Chloromethyl)furfural (CMF), a versatile bio-platform molecule, was first synthesized in a three-constituent deep eutectic solvent (3c-DES) including choline chloride, AlCl₃  ⋅ 6H₂ O, and oxalic acid. In particular, 3c-DES was conducive for the production of CMF from glucose and provided a CMF yield of 70 % at 120 °C within 30 min. In addition, CMF yields reached up to 86, 80, 30, 29, and 35 % from fructose, sucrose, cellulose, bamboo, and bamboo pulp, respectively. This study opens new avenues for the preparation of CMF.

High Yielding Acid-Catalysed Hydrolysis of Cellulosic Polysaccharides and Native Biomass into Low Molecular Weight Sugars in Mixed Ionic Liquid Systems

Ionic media comprising 1‐butyl‐3‐methylimidazolium chloride and the acidic deep eutectic solvent choline chloride/oxalic acid as co‐solvent‐catalyst, very efficiently convert various cellulosic substrates, including native cellulosic biomass, into water‐soluble carbohydrates. The optimum reaction systems yield a narrow range of low molecular weight carbohydrates directly from cellulose, lignocellulose, or algal saccharides, in high yields and selectivities up to 98 %. Cellulose possesses significant potential as a renewable platform from which to generate large volumes of green replacements to many petrochemical products. Within this goal, the production of low molecular weight saccharides from cellulosic substances is the key to success. Native cellulose and lignocellulosic feedstocks are less accessible for such transformations and depolymerisation of polysaccharides remains a primary challenge to be overcome. In this study, we identify the catalytic activity associated with selected deep eutectic solvents that favours the hydrolysis of polysaccharides and develop reaction conditions to improve the outcomes of desirable low molecular weight sugars. We successfully apply the chemistry to raw bulk, non‐pretreated cellulosic substances.

The role of the molecular formula of ZnCl2·nH2O on its catalyst activity: a systematic study of zinc chloride hydrates in the catalytic valorisation of cellulosic biomass

We show the efficient and direct transformation of a range of low value cellulosic substrates such as lignocellulose and algal biomass, into higher value chemicals, including low molecular weight reducing saccharides and furanoid products.