Experimental Study On The Catalytic Gasification Of Pine Sawdust And The Cracking Of Toluene On Copper Slag Supported Nickel Catalyst

Biomass gasification is one of the most effective ways which use biomass energy,its main purpose is to produce high quality gas,but the hydrogen content produced by the direct gasification of biomass is low,and tar is inevitably produced.Tar not only has serious effects on gasification system,gas equipment,ecological environment and human health,but also contains energy that is not utilized which causes reduction in gasification efficiency.Copper slag is an important waste in the smelting process of copper,a lot of copper slag is produced during the process of copper smelting and frosting.Main deposits of copper slag are 2FeO·SiO₂,Fe₃O₄ and Ca?Fe,Mg??SiO₃?₂,and the chemical composition is very similar to that of olivine.In this paper,high efficient Ni/copper slag?Ni/CS?catalyst which improved the gas quality and reduced the tar content was prepared by waste copper slag.Ni/CS catalyst was prepared by impregnation method with copper slag as the carrier,Ni?NO₃?₂·6H₂O as the precursor.The catalyst which was calcined in high temperature had great changes in structure and properties,and the effective active factors such as NiO,MgNiO₂,Mg_0.4Ni_0.6O,NiFe₂O₄,Fe₃O₄,MgFe₂O_4,Fe₂O₃ and CaO was obtained.XRD,TEM,BET,SEM,H₂-TPR,et al were used to characterize the catalyst of different calcination temperatures and different nickel loadings before and after reaction in order to analyze the morphology characteristics,the phase structure,reduction performance,et al of the catalyst.Focus on evaluation of catalytic activity of catalyst and explore catalytic mechanism of Ni/CS catalyst in the process of biomass gasification and toluene steam reforming reaction.In order to optimize the experimental parameters,the experiment of biomass steam catalytic gasification was carried out by using the secondary fixed bed reactor in the laboratory.The effects of different nickel loadings,catalyst calcination temperatures,steam flow and catalytic temperatures on catalytic gasification were investigated.The results showed that the copper slag Ni-based catalyst had a relatively low surface area.However,it showed an excellent resistance performance to the coke deposition and displayed the high tar removal ability.The H₂ yield,carbon conversion and carbon deposit were respectively 26.91mmol/g,94.86%and 0.16%under the condition of2.0%nickel loading and 600?calcination temperature.When the catalytic temperature increased from 850?to 900?,H₂ yield increased by only 0.28 mmol/g.Based on the comprehensive consideration of energy consumption,catalytic performance and equipment spoilage,the optimal catalytic temperature was 850°C.Toluene is one of the most representative organic compounds produced in the process of gasification and is a stable aromatic compound,thus being selected as a model compound for biomass tar.Still adopting two-stage fixed bed reactor for toluene steam reforming experiment,the effects of different nickel loadings,catalyst calcination temperatures,calcination temperature,catalyst toluene flow,the S/C on toluene conversion rate were investigated,at the same time,change of catalyst activity in the reaction process was observed.The results showed that on the reaction conditions of catalytic temperature for 850?,toluene flow rate for 2.0 mL/min,and S/C for 3,the catalyst of 2.0%nickel loading and 600?calcination temperature got the biggest initial toluene conversion rate of 99.8%,and the catalytic stability was good.It can be seen the application of copper slag in nickel catalyst could realize the reutilization of waste materials,indicating significant practical values.