Effect of calcium based catalyst on production of synthesis gas in gasification of waste bamboo chopsticks

This study investigated the effects of calcium based catalyst (calcium oxide) on variation of gas composition in catalytic gasification reaction stages by controlling the gasification temperature between 600 °C and 900 °C whilst varying a catalyst/biomass ratio from 0 to 0.2 w/w. The tested biomass generated from used bamboo chopsticks were used as the feedstock. To assess the gas composition variation, the ratio of H2/CO, H2/CO2, CO/CO2, and 3H2/CH4 are four important factors that affect the performance of catalytic gasification process. The maximum ratio of H2/CO increased from 0.23 to 0.72 in the gasification temperature range between 600 °C and 900 °C and 0%–20% calcium based catalyst addition ratio. This is due to enhanced H2 production as a result of the facilitated water–gas shift reaction. The ratios of CO/CO2 and 3H2/CH4 increased significantly from 0.9 to 2.1 and from 2.6 to 4.1, respectively, when the gasification temperature increased from 600 °C to 900 °C and 20% catalyst addition ratio. Obviously, the high temperature and catalyst addition are favorable for production of CO and H2 during gasification of tested biomass. In conclusion, the tested mineral calcium based catalyst (CaO) can help facilitating the reaction rate of partial oxidation and water–gas shift reaction, enhancing the quality of synthesis gas, and reduction of the gasification reaction time. This catalyst has potential application in gasification of waste bamboo chopsticks in the future.

► High temperature and CaO addition are favorable for syngas production in gasification.
► The catalyst can help facilitating the rate of water–gas shift reaction.
► The catalyst can enhance the syngas quality and reduce the gasification reaction time.