Liquid Fuels from Thermochemical Conversion of Biomass
Karumuri Subbarayudu, Ph.D, 03
Supervisor(s): Anuradda Ganesh, Kannan N. Iyer
In view of the growing interest in pyrolysis of biomass for fuels for fuels and chemicals, there have been many attempts to maximize the yields of the liquid product and optimize process conditions specific to the chemicals required. Even though the liquid yields obtained are as high as even 80 pecent, water constitutes for almost 30 pecent of the fraction. To be able to use as fuel, further processing (which in itself is difficult because of thermally unstable nature of oil) is generally assorted to, thereby further increasing the complexity. The first part of the study involves investigation on the influence of staged condensation on in-situ separation of the bio-oil from total liquid during the condensation process itself. The bio-oil quality thus obtained and their respective yields have been analysed for. Having established the condensation technique for in-process oil separation, further studies on oil yields and their major constituents, specific to various biomass have been attempted. Correlations to predict char, oil and total liquid yields have been developed. The difference in the behaviour of groundnut shell and rice husk is explained. Also, the influence of preatreatment on the product distribution has been experimentally investigated. Correlations to predict char, oil and total liquid yields from pyrolysis of treated biomass have also been developed. An important contribution has been the study of bio-oil to liquid ratios for various biomass (for both untreated and treated biomass). This has relevance while deciding the biomass, biomass mix and feedstock preparation, for a particular end-use.