Gasification of α-O-4 linkage lignin dimer in supercritical water into hydrogen and carbon monoxide: Reactive molecular dynamic simulation study

Gasification of lignin in supercritical water is an efficient and clean way to convert biomass to high value-added fuel. The gasification mechanism of alpha-O-4 linkage lignin dimer in supercritical water is investigated by using ReaxFF reactive molecular dynamic simulation in this study. The gasification process of alpha-O-4 linkage lignin dimer, the effects of temperature and alpha-O-4 linkage lignin dimer/H2O ratio on the gasification of alpha-O-4 linkage lignin dimer are investigated. The results indicated that the major products of alpha-O-4 linkage lignin dimer are H2 and CO, and the yield of former is higher than that of latter. The first stage of the gasification process of alpha-O-4 chain lignin dimers under supercritical water conditions is the pyrolysis of alpha-O-4 chain lignin dimers, in which the alpha-O-4 bonds are broken to generate corresponding C5-C10 products. The conversion of C5-C10 and other C1 -C4 products to H-2 and CO is promoted by the H2O molecules. This work could provide an environmentally friendly, efficient and viable way for the conversion of lignin into high value-added fuel and relieve the stress of energy shortages and environmental pollution.

Automated summary

Gasification of lignin in supercritical water is an efficient and clean method for converting biomass into high value-added fuel. This study investigated the gasification mechanism of alpha-O-4 linkage lignin dimer in supercritical water using ReaxFF reactive molecular dynamic simulation. The results showed that the major products were H2 and CO, and the conversion of C5-C10 and other products to H2 and CO was promoted by H2O molecules.