554 / 2018-09-28 16:01:09

Gasification of Anaerobic Digestion Based Residuals for H2-Rich Gas Production

生物质燃气 > 生物质燃气

Proper disposal of digestate is an inevitable problem in the development of anaerobic digestion process. An overall scheme for utilization of both solid digestate and liquid biogas slurry in the residuals is introduced. Relevant experiments and evaluations are involved. Due to the lignin rich property and the energy attributes of solid digestate, it was utilized for H2-rich gas production through thermo-gasification. Downdraft fixed bed gasification of solid digestate was performed, improved molar ratio of H2/CO close to 1 was observed, which was much higher than the value obtained from the biomass (0.6-0.7) not subjected to anaerobic digestion process. Anaerobic digestion pretreatment of corn straw (CS) with duration time of 14 d could significantly improve the H2 yield during gasification, compared with the raw CS, the value increased about 63%. Catalytic steam reforming of liquid biogas slurry was performed over Ni/a-Al2O3 catalyst. The influence of different digestion substrates and the catalytic behavior during this progress were researched. Among cattle manure, fish intestine and wheat straw digested biogas slurry, cattle manure digested biogas slurry showed highest H2 yield and feedstock conversion rate, which were about 13L(H2)/L(biogas slurry) and 97.1%, respectively. The enhanced H2 generation performance is attributed to higher TOC value in cattle manure digested biogas slurry and a special catalyst reconstruction behavior during its reforming progress. The results seem interestingly valuable in promoting the utilization of anaerobic digestion based residuals.