| Syngas is an important material of organic synthesis in the chemical industry.CH4-CO2 reforming is one of the most effective methods for producing synthesis gas.This method simultaneously utilizes two major greenhouse gases to realize resource utilization,which is of great significance to reduce environmental pollution and achieve the strategic goal of carbon peak and carbon neutrality.Fe and Ni are two kinds of green cheap metal catalysts,but their catalytic activity is low,and easy to carbon deposition and sintering.The existence of the electric field will polarize the electron orbits of the reactant molecules,and improve the adsorption capacity of the molecules.At the same time,the hot electrons generated by the electric field excited on the metal surface have a synergistic effect with the catalysts,which improves the catalyst activity,reduces the reaction temperature and activation energy,and effectively reduces the energy consumption required by the reforming process.In this paper,a cheap catalyst was prepared with activated carbon as carrier and Fe and Ni as active components.Based on the coupling between electric field and catalyst,the feasibility of using electric field as a new catalytic process combined with a cheap catalyst to replace the precious metal catalyst was discussed.And the analysis of the influencing factors of the reforming reaction and the study of the process characteristics was carried out.Using activated carbon after washing treatment and Al2O3 as two carriers,the effect of the conductivity of the catalyst carrier on the electric field catalytic reforming reaction was studied.When the coconut shell granular activated carbon was washed 8 times at 100?,the conductivity was 9.326?S/cm,which has the best electric field catalytic effect.The synergy between the electric field and the catalysts was studied,and the effects of the catalysts,active component loading,current,and air velocity on the conversion rate of the reforming reaction were mainly investigated at a low temperature of 400?.The main findings are as follows:1)Compared with a single metal catalyst,Fe-Ni bimetallic catalyst has a better catalytic effect;2)Due to the existence of the electric field,the reforming reaction has a good conversion rate at a lower temperature of 400?.When the current intensity increases from OmA to 9mA,the conversion rates of CO2 and CH4 increase from 0 to 29.4%and 19.6%,respectively,and the reforming reaction does not occur at this temperature when there is no electric field;3)Regardless of monometallic or bimetallic catalyst,as the content of active components Fe and Ni increases,its catalytic activity first increases and then decreases.In this experiment,when the Fe-Ni loading is 10%,the conversion rate of CO2 and CH4 is the highest,and the selectivity of CO and H2 is the best;4)When the current intensity increases from 0mA to 9mA,the temperature increase on the catalyst bed is less than 26?,indicating that the thermal effect of the current is not the main reason for the improvement of the reforming reaction efficiency;5)The conversion rate of CO2 and CH4 and H2/CO ratio decrease with the increase of air velocity.In order to reveal the change characteristics and mechanism of the reforming reaction,the reforming reaction process under electric field was studied.It was found that,according to the reaction rate,the reforming reaction could be divided into three stages:the rapid rise stage(0-3min),a slow rise stage(3-6min).and a steady stage.The reforming reaction tends to be stable as a whole when the reaction lasts about 6min.In the test time of 200min,the CO2 conversion rate and CH4 conversion rate almost remained unchanged,and the H2/CO ratio remained stable.The catalysts before and after the reaction were characterized and analyzed,and it was found that as the reaction proceeded,the specific surface area and total pore volume of the catalyst increased.The average pore size showed a downward trend with the progress of the reaction,and at the same time,the active components diffused and migrated,and the degree of dispersion increased.According to the results,the mechanism of Fe-Ni bimetallic catalyst used in reforming reaction under the electric field was analyzed. |
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