Catalytic Steam Reforming Of Phenol As Model Compound Of Tar In Biomass Gasification Over A Novel Palygorskite

As a source of renewable energy,biomass is interested increasingly by the people. The technology of biomass gasification is one of the main utilization technologies of biomass.The produce gas of biomass contents 1.0-10.0%tar,which will be condensed on boilers,pipelines of transportation and the inlet devices of diesel engine in the process of utilization.So tar is a fatal weakness in the development of gasification technology.The main objective of this paper is study on catalytic removal of tar.Using Phenol as the model compound,the steam reforming of tar has been performed with the synthesized catalysts of palygorskite and the palygorskite doped with NiO.The catalyst of Ni-Palygorskite is prepared by impregnation of raw palygorskite with nickel nitrate.Before acting,the catalysts are reduced fully for 2h at 500℃by N₂.The steam reforming reactions of phenol are performed under the following reaction conditions:liquor's injection rate is equal to 0.51g/min,the catalyst quality is equal to 1.5g,space time is 0.1s,0.3s,0.5s,0.7s,S/C ratio is 0.87, 1.741,2.611,3.481,4.352,5.222,and reaction temperature is 400,500,600,700 and 800℃.The gas composition such as H₂,CO and CO₂ are investigated by GC.The performance of the series of catalysts was evaluated by the conversion ratio of Phenol.The results are as follows:all the steam reforming reaction of the catalysts, doped by 5wt%Ni(5wt%Ni/PG) has the best effect under the same reaction conditions. As the temperature increasing,the level of catalytic cracking gradually deepened,the yields of H₂ and the H₂ selectivity also added.The influence of the steam/carbon molar(S/C) ratio on gas yields has been studied for values from 5.222 to 0.87,yields of H₂ decrease,while CO yields increase when S/C diminishes.And then,apply one set of composition model and Arrhenius for tar Catalytic theorem,analysis of experiment data,calculate reaction speed and activation energy for caloric reforming and catalytic reforming process.The result is catalytic reforming need low activated energy 141.1kJ/mol compared with thermal cracking reforming 176.7kJ/mol,it show anastomose with experiment.