The Heterogeneous Reaction Between Tar And Ash From Waste Biomass Pyrolysis And Gasification

Fossil energy resources that are available in the world are exhaustible. Therefore, the renewable biomass resource has attracted a lot of attention as the future energy resource. In addition, it is an advantage that the biomass grows while absorbing CO2, contributing to the prevention of global warming. Biomass utilization technologies are classified as pyrolysis and gasification, fermentation, and combustion. Fuel gases and synthesis gases produced by the pyrolysis and gasification is used as power generation, heating, chemical products, etc. However, pyrolysis and gasification processes also generated condensable organic compounds, so-called “tar”. Most tar contents are present as the gases at high temperature. However, when the temperature is cooled down lower than their boiling point, causing a black oily liquid lead to the equipment failure, the appropriate processing is required. As the processing method, using the catalytic tar decomposition has been widely studied. In the present study, we have carried out the thermal decomposition of cellulose, in the experimental apparatus modeling a fluidized bed gasifier. The thermal decomposition of cellulose, tar and gas is generated, tar is collected and cooled, and the gases were measured by a gas-chromatograph with a flame ionization detector (GC-FID) and with a thermal conductivity detector (GCTCD). Then, K and Ca are selected as the catalysts of alkali metals and alkaline earth metals contained in the waste biomass. They are present in the state of oxide or carbonate during pyrolysis and gasification. We conducted a similar experiment. The amount of condensable products and heavy tar were decreased by installing K2CO3 and Ca(OH)2. Additionally, they brought further gas