Study On Reforming Process Of Methane With Carbon Dioxide

Seeking for clean energy to adapt the social development due to the decrease of reserves of petroleum day by day and with environment pollution generated. In the meanwhile, CO2 emission is becoming more and more with industrial development, which brings significant impact on the environment. Synthesis gas prepared by CO2 reforming of methane is utilizing two greenhouse gases, CH4 and CO2, which is crucial to environment protection and eco-balance. Therefore, the reaction of CO2 reforming of methane has been receiving people's attention. However, this technology has not applied to larger-scale industrialization because of inactivation of catalyst with carbon deposition in dry reforming of methane. Today, researchers mainly study how to enhance the ability of catalyst to anti-carbon deposition and its stability.In this study, the effects of different process conditions on the three catalysts in dry reforming of methane were investigated. To different catalyst, the best process condition of dry reforming of methane is different, too. The best process condition of each catalyst in dry reforming of methane could be obtained from these tests below. In the first, through co-precipitation and impregnation, three catalysts were prepared, namely 10wt%Ni/Mg-Al-LDO,10 wt%Ni-6wt%Co/Mg-Al-LDO and 10 wt%Ni-6wt% CeO2/Mg-Al-LDO. After characterized by XRD, TPR, BET and TG, it was found that all the prepared catalysts could be applied to the reaction of dry reforming of methane. Secondly, we used WFSM-3060 catalyst activity evaluation device from Tianjin Xianquan Company and SP-6890 gas chromatograph to imitate the process of dry reforming of methane. We first took CH4 conversion rate as the target and used orthogonal experiment to find the best process condition range of each catalyst in dry reforming of methane. And then the effects of temperature, ratio of CH4/CO2 and GHS V on dry reforming of methane of each catalyst were investigated by single factor experiment. At last, the best process condition was determined according to reactant conversion rate, product selection. As a result, the conclusions were as follows:1. The best process condition of dry reforming of methane by Ni/Mg-Al-LDO catalyst was that temperature was 750?, ratio of CH4/CO2 was 1:1.5 and GHSV was 18000ml·gcat-1·h-1. Under this condition, after reaction of 10h, CH4 and CO2 conversion rate were respectively reduced from 80.6% to 70.7% and from 55.1% to 49.2%. The selection of H2 and CO was also decreased from 96.3% to 90.5% and from 95.9%to 91.5%. The catalyst stability was low.2.The best process condition of dry reforming of methane by Ni-Co/Mg-Al-LDO bimetallic catalyst was that temperature was 765?, ratio of CH4/CO2 was 1:1.3 and GHSV was 21000ml-gnt-1·h-1. Under this condition, after reaction of 10h, CH4and CO2 conversion rate were respectively reduced from 83.9% to 78.8% and from 65.5% to 61.6%. The selection of H2 and CO was also decreased from 97.9% to 93.4% and from 98.5% to 92.1%. The catalyst stability was fair.3.The best process condition of dry reforming of methane by Ni-CeO2/Mg-Al-LDO catalyst was that temperature was 765?, ratio of CH4/CO2 was 1:1.1 and GHSV was 21000ml·gcat-1h-1. Under the condition, after 10h reaction, the CH4 and CO2 conversion was separately 83% and 75%, while H2 and CO selection was 95.6% and 94.5%. The catalyst stability was fine. By comparing, it was concluded that under the best process condition, Ni-CeO2/Mg-Al-LDO is better than the other two catalysts on catalyzing the reaction of dry CH4 reforming.