Study on pore structure properties of steam activated biomass chars

摘要

Wheat straw and rice husk chars were prepared in a fixed bed reactor at different pyrolysis temperatures (673K,873K and 1073K) and different pyrolysis procedure. The steam activated chars were also prepared in a fixed bed reactor at the following conditions: activation temperature is 1073K, the flow rate of N2 is 5 L/min,and N2 and H2O molar ratio is 1:1. The specific surface area,pore structure and micro-morphology of different kinds of prepared biomass chars were measured by NOVA1000e analysis instrument and JSM-5610LV scanning electron microscopy (SEM),respectively.Results indicated that the internal structure was improved significantly by steam activation through enlarging the specific surface area and enriching the porosity. The wheat straw char prepared by both rapid pyrolysis at 873K and activation by steam is better than others,whose DR surface area increases from 3.10m2/g to 1099.99m2/g. The N2 adsorption volume of steam activated biomass chars has been significant promoted.