Experimental Investigation of Tar Reduction Properties by Coupling Oxidative Pyrolysis and Partial Oxidation in a Continuous Reactor for Biomass Gasification

摘要

To develop a deep understanding of multistage biomass gasification technology, the effect of oxygen concentration in the pyrolysis stage on the overall performance of the gasification process was investigated. The results showed that oxygen in the pyrolysis stage promoted the yields of permanent gases and reduced the yield of tar. The GC–MS analysis of pyrolyzed tar compounds indicated that oxidative pyrolysis promoted the conversion of the reactive primary tar compounds to more stable secondary tar compounds. The FTIR analysis of pinewood char showed that oxidative pyrolysis reduced the content of oxygen-containing functional groups and improved the aromatization of char. The partial oxidation results showed that the CO and CO2 yields both increased with the increase of oxygen concentration in the first stage. The tar yield after the partial oxidation stage was reduced from 0.0809 (0% O2 in the first stage) to 0.0064 kg kg_(pinewood)~(-1) (15%O2 in the first stage).