湿生物质催化气化固体产物的微观结构分析

Microstructure Analysis of Solid Products of Wet Biomass Catalytic Gasification with CO_2 Absorption

为深入地认识一种伴随有CO2吸收的湿生物质催化气化技术,对该过程中有代表性的固相:如,半焦、吸收剂、催化气化固体残留物进行微观结构分析.结果表明:湿生物质半焦具有更加丰富的微孔结构,其比表面积和孔容积相对于干物质半焦分别增加了17%和19%;Ca(OH)2以及水合Ca(OH)2的高温分解能提高比表面积和孔容积,且产物CaO的孔径分布随水合Ca(OH)2中水分含量的增加而上升.温度对湿生物质催化气化固体残留物的微观结构有较大的影响,随着温度的升高,其比表面积曲线呈S型,孔容积曲线则先略微降低后迅速升高.

To investigate the catalytic gasification of wet biomass with CO2 absorption, the microstructure of several representative solids, such as biomass semicoke, absorbents, and solid residues of catalytic gasification of biomass, was determined with N2 adsorption. The results show that the semicoke of wet biomass has more plentiful micropores than that of dry biomass, and its specific surface area（ABET） and total pore volume（Vp） is increased by 17% and 19%, respectively. Both ABET and Vp of CaO are much higher than that of its precursors （Ca（OH）2 and hydrated Ca（OH）2）. The PSD of CaO increases as the ratio of water to Ca（OH）2 increases. Furthermore, with the increase of reactor temperature, the trend of ABET curve presents ＇S＇ type, and Vp curve decreases slightly, and then fast increases.