Study On The Preparation Of Gas Modified Supported Pyrolysis Coke Catalyst And Its Mechanism In Heavy Tar Cracking

In this paper,pyrolysis coke(PC)was used as the carrier,and ZnO/PC catalyst was prepared by gas modification and plasma roasting.Gas tar produced by pyrolysis of raw coal was catalyzed by the catalyst.The experiment adopted a two-stage pyrolysis fixed bed,coal was placed in a furnace,and a catalyst was placed in a two-stage furnace.Gas tar generated by a frrnace passed through a two-stage furnace,cracking reaction occurred under the catalyst,and the gas production volume and the quality of tar was improved.The catalysts were characteri.zed by FT-IR,XRD,XPS,BET and SEM.The cracking mechanism of catalyst cracking tar was studiedFirstly,PC with different final temperatures and different constant temperatures time was prepared and cracked tar.The effects of PC on pyrolysis products were studied.Optimal preparation conditions of PC were selected.Secondly,the optimal PC was used as the carrier,the optimal PC was modified by gases(H2O,CO2,NH3),and the optimal PC with different flow rate modification,different temperature modification and different time modification were prepared and modified PC cracked tar.The effects of PC modified on tar cracking products were studied,and the optimum preparation conditions were selected.Finally,the optimal PC modified by gas was used as the carrier,and the load-type PC catalysts with plasma different roasting time,different roasting power and ZnO different load(5%,10%,15%)were prepared.The effects of ZnO/PC catalyst on tar cracking products were studied,and the optimal plasma roasting ZnO/PC catalyst was preparedThe results showed that:(1)the optimal preparation conditions for PC was 750°C and 2h;(2)the optimal modified gas was H2O,and the optimal preparation conditions were 450mL/min,650? and 60min,the optimal modified PC had better cracking of tar,and the gas production,tar quality and tar composition had been further improved;(3)when plasma roasting time was 5min,roasting power was 60W,and ZnO load was 10%,the load-type PC catalyst was the best for cracking tar;(4)the tar was cracked by the optimum plasma roasting ZnO/PC catalyst,the quality of the cracked tar was increased by 119.8%,gas production was increased by 66.2%,and the total content of light oil,phenolic oil,naphthalene oil and washing oil in tar was increased by 85.8%.