Steam gasification of biomass-derived char for the production of carbon monoxide-rich synthesis gas

There is growing interest in the conversion of biomass and related materials into gaseous and liquid fuels. During fast pyrolysis of biomass in a fluidized-bed reactor, 15% of biomass is converted to char whereas 70% is converted to liquid, and the rest to gas. In the present work, a systematic study has been conducted to explore the possibilities of using biomass-derived char for the production of various types of gaseous fuels and synthesis gas through pyrolysis and steam gasification in a tubular reactor. The pyrolysis experiments were carried out in the presence of nitrogen ( flow rate of 20 mL/min) in the temperature range of 700-800 degreesC. Steam gasification,experiments were carried out in the temperature range of 650-800 degreesC, steam now rate of 2.5- 15 g/h/g of char, The reaction time was Varied from, 0.5 to 2.0 h. It has been found that a combination of lower steam now rate (about 2.5 g/h/g of char), lower temperature (about 700 degreesC along with fewer reaction time (about 0.5 h) produces synthesis gas having a molar ratio of H-2/CO favorable for Fischer-Tropsch synthesis. On the other hand, synthesis gas having very high H-2/CO molar ratio (about 5-6) can be produced via the steam gasification reaction at a temperature of 800 degreesC, steam flow rate of about 10 g/h/g of char and a reaction time of 0.5 h: The heating value of the product gas at different process conditions has also been calculated.