Hydrolytic de-polymerization of hydrolysis lignin using alkaline catalysts: effects of process parameters and optimization
Hydrolysis lignins (HL) are a byproduct from acid or enzymatic biomass pretreatment processes such as the ones employed in cellulosic sugar and/or ethanol plants. They are mainly composed of lignin , unreacted cellulose and mono and oligosaccharides. These lignins are, to a great extent, covalently bonded to cellulose and/or hemicellulose to form lignin carbohydrate complexes (LCCs) thereby making them insoluble in alkali and most common organic solvents â this, obviously, limits the range of applications in which they can be used, in particular, as a bio-substitute for aromatic chemicals for the synthesis lignin-based materials such as lignin-based phenol formaldehyde, polyurethane and epoxy resins. To address the above challenges in the valorization of HL as a chemical feedstock, this research targets hydrolytic depolymerization of HL in water in the presence of an alkaline catalyst to obtain de-polymerized hydrolysis lignin (DHL) with a much lower molecular weight, a higher solubility in various common solvents and, as a result, a higher chemical reactivity. In this proposal, different types of alkaline catalysts will be tested as catalysts for the process. TO BE CONT.