Explosive decompression pretreatment: nitrogen vs. compressed air
Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56
EE51014 Tartu, Estonia
Lignocellulosic material is the most promising feedstock for the bioethanol production however, due to complicated physico-chemical characteristics of biomasses, it is necessary to pretreat the biomass before the bioethanol production. The goal of the pretreatment is to open the biomass structure for enzymatic hydrolysis to gain higher sugar and ethanol yields in further processes. In this paper a novel explosive decompression pretreatment is studied where two gases – nitrogen and compressed air are utilized for pressure generation. For this, traditional three-step bioethanol production process was used, where explosive decompression pretreatment with N2 gas or compressed air was applied for biomass pretreatment. Glucose and ethanol concentrations were measured during the process. Glucose and ethanol yields and process efficiencies were used to evaluate the effect of explosive decompression pretreatment and its suitability for biomass pretreatment in bioethanol production process. Results show that the highest glucose yield was gained when nitrogen gas was used, while difference in glucose yield compared to that of autohydrolysis was negligible when compressed air was applied.