LIGNIN PYROLYSIS IN A CIRCULATING FLUIDIZED BED-INFLUENCE OF TEMPERATURE AND CHAR FORMATION ON BED MATERIAL

摘要

In this work, the pyrolysis of Kraft lignin in a circulating fluidized bed has been studied.The focus lies on the pyrolysis mechanism and on the influences of temperature and char accumulation in the bed on liquid product yields and composition.Also the yield and composition of gaseous products and char are investigated.The pyrolysis oil yield has its maximum at 650℃.The char yield decreases with rising temperature, while the gas yield in contrary rises.With increasing char deposition on the bed material, oil yield decreases in the considered range by about 10-20 ％.It can be observed that with increasing char deposition on the bed material the pyrolysis oil composition is shifted towards smaller molecular weight.