Carbon Dioxide Reforming Of Coke Oven Gas To Produce Carbon Monoxide Over Ni/Fly-ash

Carbon dioxide emission from fossil fuels is increasing, which accelerats the greenhouse effect. Therefore, CO2 resource utilization has become an urgent task to be solved. Coke oven gas is a byproduct of the coke plant, which contains large amounts of hydrogen and methane. Realization of utilization of clean coke oven gas has been very significant. It is researched that CO is produced to synthesize basic organic chemicals through CO2 reforming of coke oven gas in the paper. The research of catalyst is essential in this study. Fly ash has the heat resistance and a certain amount of specific surface area. Thus it can be used as the carrier for catalyst at the low price. It can have also created a new process for the research of CO2 reforming of coke oven gas to produce CO.Firstly, the blank fly ash catalyst activity has been studied in the condition of a volume ratio of feed gas V(CH4):V(H2):V(CO2)=1:2.23:5.23 and total space velocity of 3500h-1 at 700-1100?. It shows that the presence of Fe2O3 in fly ash causes CO2 conversion higher than CH4 conversion. Through loading 5 wt% Ni and impregnated with different nitric acid concentrations, the activity of 5 wt%Ni/fly ash is related to nitric acid concentration. It is taken into account that the anti-coking ability of 5 wt%Ni/fly ash modified with 1.0 mol/L nitric acid is the best, which the coke yield reaches 5.87% at 1100?. XRD and H2-TPR show that Ni species has the strong interaction with Fe species present in mullite lattice of fly ash. NiAl2O4 spinel is generated and can be reduced to Ni°that has played a catalytic role during the preparation of the catalyst. It is taken consideration that the catalytic activity modified with 1.0 mol/L HNO3 is the best. In addition, the reduction way also has a significant impact on catalytic activity and anti-coking property.Secondly, three kinds of different additives are added into Ni/fly ash, which are as following:the alkaline earth metal oxides CaO and MgO, the transition metal oxides CuO and Fe2O3, the rare earth oxide CeO2. The conclusions are obtained that adding 1 wt% CaO and MgO additives can improve catalytic activity. Especially, CH4 conversion of CaO-Ni/fly ash reaches 100% at 800?. However, its anti-coking capacity is slightly weaker than MgO-Ni/fly ash and Ni/fly ash. CuO and Fe2O3 are added to improve the catalyst activity and reduce the interaction between NiO and carrier, resulting in the reduction temperature decreasing. Meanwhile,1 wt% CuO introduced slightly reduces carbon deposition of the catalyst. CH4 and CO2 conversion on CeO2-Ni/fly ash reach 100% and 64.17% at 1100?, respectively. Adding CeO2 greatly improves the ability of the anti-carbon catalyst. Therefore, the modified Ni/fly ash catalyst exhibits superior reactivity at high temperature in the present reaction system through adding additives.