Simultaneous gasification and reforming of biomass on Ni/Dolomite in fluidized bed

Abstract

Pyrolysis of biomasses accompanied by its successive steam gasification to synthesis gas was studied by a Temperature Programmed Reaction (TPR) method. Tars were produced at 200-400 ℃ and little tars were produced above 400 ℃. Reactions of char, which was formed during pyrolysis of biomass, were subjected to the reactions with steam by Temperature Programmed Reaction (TPR) method. Gas formations started at around 600 ℃ and reached the maximum level about 830 ℃ irrespective of the low material and finished at 850 ℃. The main gaseous products of the char gasification were H₂, CO, CO₂ and lesser amount of CH₄. The carbon conversion in the fixed bed was around 62-77% in carbon basis. Among the four types (pine wood chip, bamboo, coconut and corncob), corncob was the most suitable biomass to be pyrolyzed. On the other hand, pine wood chip was more difficult to be pyrolized. The amount of char obtained in the pyrolysis was the largest for pine wood chip (28.2 wt%) and the smallest for corncob (21.7wt%) in dry basis. Simultaneous gasification and steam reforming of the biomass on Ni/dolomite catalyst in fluidized bed reactor were studied in the gaseous production in the one stage reactor. The parameters such as temperature, steam flow rate, biomass feed rate, gas flow rate for fluidization, oxygen flow rate and catalyst types were studied to produce the high gaseous products including tar elimination. The temperature at 780 ℃, steam flow rate of 222 mmol/h, gas flow rate for fluidization 450 ml/min and oxygen input 50 ml/min were found to be the suitable conditions. The Ni/Dolomite and the developed Ni/Dolomite were also studied about their performance. It can be confirm that Ni/Dolomite and the newly developed Ni-WO₃/Dolomite show high performance in biomass gasification. The various types of biomass (pine wood chip, coconut shell, bamboo, corncob and palm shell) were selected to study the difference of gas production in gasification and reforming.