Study On Catalytic Pyrolysis Of ShangWan Bituminous Coal And Deactivation And Regeneration Of Catalyst

Coal pyrolysis refers to the complicated process of a series of physical and chemical conversions under the isolated air or inert atmosphere conditions,different temperatures and pressure effects.This technology not only can realize efficient utilization and clean conversions of coal,but also can gain high value-added chemical products and clean fuels under the different states,such as solid fuels,liquid fuels and gas fuels.Meanwhile,the mutual synergy of each conversion process is used to do global optimization on the material flow,energy flow and energy consumption.Meanwhile,it can realize rational utilization of H/C ratio,gradient utilization of heat and sufficient utilization of substances.Pyrolysis plays a direct action on the multi-joint process for subsequent conversion of coal in all coal conversion process technology,such as gasification,combustion and liquidation,and so on.Coal pyrolysis characteristics cause a direct influence on coal conversion utilization rate,thus studying pyrolysis poly-generation technology has the important guiding significance in the experimental stage or industrial stage.By aiming at influences of different catalysts,different size particles,different atmospheric working conditions and different reaction system pressure on coal pyrolysis characteristics,the author analyzed deactivation and regeneration of catalysis.The findings showed that under the different catalysts,Ni/Al₂O₃ and Mo/HZSM-5 catalysts in CH₄ reaction atmosphere could be mixed up with coal to gain the best tar yield at the specific pyrolysis temperature.When pyrolysis temperature was 550?,tar yield was up to 17.1%,gaining the increase of gas yield and reduction of semi-coke yield.At the same time,this was good for removing heteroatom in tar.Size particles caused a great influence on coal catalytic pyrolysis and the yield changes were relatively obvious.With the increase of coal size particles,the yield of tar and gases was reduced with it,while the semi-coke yield was increased with it,indicating that conversion rate was slightly reduced.As inspecting different atmospheres,under CH₄+CO₂ working condition,with the constant increase of temperature,tar yield was slightly improved.At 750?,tar yield reached the maximum 16.4%.As adding CO₂,the yield for H₂ and CO was significantly affected and the yield was increased.This was beneficial to come off sulphur content in semi-coke and the effect was relatively obvious.Under the different pressure effects,with the increase of pressure,tar yield was firstly increased and then reduced.When pressure was 1.20 MPa,the yield was up to 17.9%,which was greatly higher than the normal pressure environment and coal gray-king dry-tar yield.Coal pyrolysis semi-coke was conducted by SEM analysis,finding that under the high-pressure condition,there was irregular structure and opening hole in interior.The superficial area of catalysts not only will affect catalytic activity,but also will weaken activation efficiency of reaction atmosphere.The roasting manner can regenerate inactivated catalysts and show the significant regeneration effects.Based on the above-mention study,the author inspected coal pyrolysis under the different catalytic,different size particles,different reaction atmospheres,pressure changes in the reactions system,catalytic deactivation and regeneration technology process in reaction process,thus to carrying out coal pyrolysis poly-generation technology has the important guiding significance on improving tar yield and quality in coal pyrolysis and coal pyrolysis poly-generation technology,hoping to provide the reference and guide for catalytic coal pyrolysis poly-generation technology study in the later phase on the basis of exploration and study.