Development of a Unique Downdraft Gasifier System for Low Bulk Density Biomass Materials

摘要

Gasification is a proven technology that has been used for over 100 years to convert carbonaceous feed into gaseous products of useable heating value. A unique downdraft gasifier has been designed andfabricated to generate synthesis gas from low bulkdensity biomass materials such as wheat straw, corn cobs, wood chips and sorghum stalks etc. Gasifier performance was evaluated using distillers dried grains with solubles (DDGS) and wood chips as the feedstocks. Gas Chromatograph (GC) was employed to analyze syngas quality. Gasification of DDGS resulted in a syngas composition (mol %) of 19% H_2 and 20% CO; as for wood chips gasification, 20% H_2 and 15% CO. Both had high concentration of N_2, which ranged from 50% to 60%. Small amount of O_2, CO_2 andCH_4 were also included in the syngas. A Tar and Particulates sampling and analysis system was also configured to measure the tars and particulates concentration in the syngas. Tar concentrations were 4.20 g/Nm~3for wood chips and 1.65 g/Nm~3 for DDGS.Future work will focus on syngas purification and system optimization.