Xu Zeng

Production of Formic Acid and Acetic Acid by Hydrothermal Oxidation of Alkali Lignin

The production of formic acid and acetic acid by hydrothermal oxidation of alkali lignin, a kind of biomasses, was investigated using a batch reactor with H2O2 oxidant. Experiments were performed over a wide range of conditions with temperature varying from 260 to 320°u2009C, oxygen supply varying from 60% to 120%, and reaction time varying from 30 to 150 s. The highest yield of formic acid was 4.9% at 280°u2009C for 120 s with the additive ratio of H2O2 100%. The highest value of acetic acid was 12.3% at 300°u2009C for 120 s with the additive ratio of H2O2 100%. Based on the intermediate products identified by GC/MS and HPLC, reaction pathways of alkali lignin are discussed. It was found that maleic acid and fumaric acid were two primary unsaturated intermediate products. The production of formic acid and acetic acid were come from the oxidative decomposition of intermediate products in the oxidation process. Increasing the formation of saturated dicarboxylic acids and glutaconic acid would enhance the acetic acid y...

The direct utilization of water for the reduction of CO2 by solar/renewable energy-driven two-step process

The Earth’s environment is threatened by an increase of CO2 concentration in the atmosphere. One of efficient methods for diminishing the imbalance of CO2 should involve the rapid conversion of CO2 into fuels and chemicals. One of the major challenges in the reduction of CO2 is the development of economical hydrogen sources. Water is the most abundant hydrogen resource. The direct utilization of water for the reduction of CO2 would be one of the most promising approaches for sustainable development in energy and environment. This paper outlines some recent advances in our researches on the reduction of CO2 with biomass as a reductant under hydrothermal conditions to directly utilize hydrogen in water.