Study On Semi-cokes And Modifide Semi-cokes As Catalysts For CO₂ Reforming Of CH₄ Production Of Synthesis Gas

In this paper,in order to avoid deactivation of the metal catalysts and reduce the high price of the metal catalysts,we put forward using semi-coke and modified semi-coke as the catalysts of CO2 reforming of CH4 reaction innovated.In this paper,using HongCe semi-coke?ShenMu semi-coke?JinCheng semi-coke?HongXin semi-coke?LiuLin semi-coke and QinYuan semi-coke as catalysts,research their catalysis on the reaction,and using related technology(XRD?SEM?FTIR?TG?BET and Acid-base Titration)to get the characterization of the semi-cokes before and after reaction.In order to study the semi-coke catalytic function deeply,using H2O2 and NH3· H2O modified HongCe semi-coke?ShenMu semi-coke and JinCheng semi-coke,Research modification conditions on the influence of reforming reaction and using related technology to get the characterization of the modified semi-cokes.Fluent was applied to study the operating parameters on the reforming process for the future experiments,such as temperature,pressure,CH4/CO2 rate and Gas-solid contact time,to provide a theoretical basis for reforming experiment,The main results as follows.1.Six semi-cokes of CH4-CO2 reforming reaction catalytic activity in order:HongCe>ShenMu>JinCheng>LiuLin>HongXin>QinYuan,the coal rank and specific surface area is the main factors of different catalytic properties,functional groups and alkaline metal compounds varieties and contents of reaction activity also have certain effect.2.Temperature effect is the main factor,the temperature rise to the transformation of gas reactions;Along with the increase of gas-solid contact time,the methane and carbon dioxide conversion rate increase first and stable trend later;Along with the increase of H2/CO rate,the H2/CO rate increase also,the reaction temperature and gas—solid contact time on the influence of the ratio of H2/CO is not obvious.3.with different semi-coke catalyst,the transformation of methane carbon dioxide showed the same change rule,that is the initial stage conversion rate is higher,with the reaction,the conversion rate gradually reduce and stabilize,for six semi-cokes for 480 min of focal research activity,catalyst remain stable catalytic performance.4.The current technology were used to characterize the active sites?the surface and the structure of semi-cokes,found after the reaction the semi-cokes surface absorption peaks of functional groups weaken or disappear,so functional groups that participated in the reforming reaction;Specific surface area reduced,semi-cokes surface have changed after reaction,Blocked gap of the HongCe semi-coke's surface were open,ShenMu semi-coke surface appear many microspores.The surface of JinCheng semi-coke made by big granular attachments become smaller and tact fragment.5.The semi-coke modified by H2O2 under high temperature and high pressure C02 reforming of CH4 catalytic effect obviously better than the unmodified semi-cokes catalytic effect,meanwhile,modified by 5%H2O2 are best.6.Modification temperature of 200 ?,250 ? and 300 ? conditions,methane and carbon dioxide conversion rate with the modification temperature increased.In the modified pressure for 4 to 8 Mpa range,the methane and carbon dioxide conversion rate increase first and reduce later.In the modification time respectively for 2 h,3 h and 4 h conditions,Along with the increase of time,the conversion rate increase too,but the increase of the small scale.7.The current technology were used to characterize the catalysts,so as to disscuss the active sites?the surface and the structure of modified semi-cokes,found modified semi-cokes surface absorption peaks of functional groups improve,Semi-cokes acid-base functional groups have been surface strengthening;alkaline functional group content increased obviously,for CO2 absorption function to strengthen;After modification,the semi-coke surface area increased.8.The semi-coke modified by H2O2 under high temperature and high pressure CO2 reforming of CH4 catalytic effect obviously better than the unmodified semi-cokes catalytic effect,meanwhile,modified by 5%H202 are better than the 2%and 10%modified one.In the modified concentration is 2%,5%and 8%,Along with the increase of Ammonia concentration,CH4 and CO2 conversion rate increase.This experiment,modified by 8%Ammonia are best?9.Modification temperature of 200 ?,250 ? and 300 ? conditions,methane and carbon dioxide conversion rate with the modification temperature increased.In the modified pressure for 2 to 6 Mpa range,the methane and carbon dioxide conversion rate increase,but the increase of the small scale.In the modification time respectively for 2 h,3 h and 4 h conditions,Along with the increase of time,the conversion rate gradually increase and stabilize.10.The current technology were used to characterize the modified semi-cokes,found modified semi-cokes surface absorption peaks of functional groups improve,Semi-cokes acid functional groups have been surface reduce;alkaline functional group content increased obviously,for CO2 absorption function to strengthen;After modification,the semi-coke surface area increased.11.Fluent was applied to study the operating parameters on the reforming process for the future experiments,such as temperature,pressure,CH4/C02 rate and Gas-solid contact time,and found that the higher the reaction temperature and Gas-solid contact time to grow more,can promote reforming reaction.Simulation data which in the ideal state is a little different from the experimental.