The Degradation and Repolymerization Analysis on Solvolysis Liquefaction of Corn Stalk

Abstract

One of the most effective and renewable utilization methods for lignocellulosic feedstocks is the transformation from solid materials to liquid products. In this work, corn stalk (CS) was liquified with polyethylene glycol 400 (PEG400) and glycerol as the liquefaction solvents, and sulfuric acid as the catalyst. The liquefaction conditions were optimized with the liquefaction yield of 95.39% at the reaction conditions of 150 °C and 120 min. The properties of CS and liquefaction residues (LRs) were characterized using ATR–FTIR, TG, elemental analysis and SEM. The chemical components of liquefied product (LP) were also characterized by GC–MS. The results indicated that the depolymerization and repolymerization reaction took place simultaneously in the liquefaction process. The depolymerization of CS mainly occurred at the temperature of <150 °C, and the repolymerization of biomass derivatives dominated at a higher temperature of 170 °C by the lignin derivatives repolymerization with cellulose derivatives, hemicellulose derivatives and PEG400 and self-condensation of lignin derivatives. The solvolysis liquefaction of CS could be classified into the mechanism of electrophilic substitution reaction attacked by the hydrogen cation.

Lignocellulose Biomass Liquefaction: Process and Applications Development as Polyurethane Foams

“…The most intensely used glycolysis agents are PEG, glycerol, ethylene glycol, and ethylene carbonate (EC), with the highest reaction rate being registered for EC [ 44 ], due to its high permittivity value [ 45 , 46 , 47 ] which makes it a very good choice for microwave-assisted glycolysis. The reaction steps in EC glycolysis are presented in Scheme 5 .…”

“…The flowchart for the research and development of a lignocellulose biomass glycolysis process is presented in Figure 4 [ 47 ].…”

“…The first stage of the technological process ( Figure 4 ) consists of the grinding and mechanical separation of the fraction with a size of less than 250 µm from the corn stalks [ 47 ]. After this stage, the selected lignocellulose biomass reacted with polyols for the depolymerization reaction in basic or acidic conditions in accordance with the selected procedure.…”

Ambient-Pressured Acid-Catalysed Ethylene Glycol Organosolv Process: Liquefaction Structure–Activity Relationships from Model Cellulose–Lignin Mixtures to Lignocellulosic Wood Biomass

“…However, it is required to firstly depolymerize and convert the macromolecular components of wood into a liquid. This can be achieved through a thermochemical process via wood liquefaction, resulting in an effective transformation of LC biomass into high-added value intermediates like bio-based adhesives and polyols [ 10 , 11 , 12 ]. The use of liquefied wood in the preparation of new polymers is not only important for the efficient utilization of renewable resources, but also provides a way to replace the raw materials otherwise produced from crude oil.…”

“…One pathway to transform lignocellulosic biomass is its direct liquefaction, which is usually accomplished using a super- or subcritical fluid at high temperatures (250–400 °C) and high pressures (5–40 MPa) for a couple of hours [ 12 ]. A more cost-effective wood liquefaction could be achieved at atmospheric pressure however, in order to attain an appropriate degree of wood liquefaction, high acid concentrations are used to catalyse the process, which at the end affects the properties of the synthesized polymers [ 13 ].…”