Dry Reforming Of Coke Oven Gas Over Perovskite-type Catalysts

Carbon dioxide reforming of coke oven gas have been a research hot spot in the last several decades. Its significance is as follow:(1) It can make full use of metallurgical waste gas, relieve the energy crisis, and achieve the sustainable development of economy.(2) Reduces the emission of greenhouse gas emissions and mitigate global warming.(3) Its H2/CO ratio is more suitable for the synthesis of methanol and FT.(4) Carbon dioxide reforming of coke oven gas is an energy storage medium. But carbon dioxide reforming of coke oven gas to syngas has not succeeded in industrial application, one problem is that the catalyst(especially non-precious metal catalyst) coke seriously, which leads to its deactivation. For the noble metal catalysts, despite their good resistance to carbon deposition, they contain expensive precious metal that needs to be recycled, which limits their industrial application. Therefore, the successful development of non-precious metal catalyst with good stability is the key to the industrialization of dioxide reforming of methane.These perovskite-type oxides were synthesized using a sol–gel method and characterized using X-ray diffraction(XRD), N2 adsorption-desor, temperature programmed reduction of H2, scanning electron microscopy, transmission electron microscopy, and thermogravimetry-differential scanning calorimetry. XRD results showed that the La0.6Sr0.4NixCo1-xO3 has formed quaternary solid solutions. The effects of Ni substitution(x) and calcination temperature on the properties of La0.6Sr0.4NixCo1-xO3 were investigated. XRD analysis of the tested catalysts showed the formation of Ni0, Co0, and La2O2CO3, among which the third one is the main active phase responsible for the high activity and stability, and the suppressed the formation of coke under severe reaction conditions. COG(rich in H2) can also reduce the deposition of carbon by inhibiting CH4 decomposition.The influence of five different support compositions(Al2O3, Ce O2, Mg Al2O4, Si O2 and SBA-15) on the catalytic performance of LN-M catalysts was further measured. LN-Al2O3 showed the lowest catalytic properties, which gained conversions of CH4 and CO2 of 80.2% and 96.1%, respectively. The XRD and TPR analyses showed the reduced nickel from the La Ni O3 deposited on the Al2O3 reacts with the latter to give rise to a spinel Ni Al2O4, which leads to its catalytical properties. LN-Ce O2 showed the highest catalytic properties and excellent resistance to carbon deposition due to the good interaction between the metal and support.Finally, the x Ni%/LNC were used in the dry reforming of coke oven gas to further study the influence of the nickel contents on the catalysts. The results showed their catalytical activity was significantly raised with the increase of Ni contents from 5wt% to 15wt%. However, when Ni content increased to 20%, the catalyst showed low catalytic activity, which was caused by the large amount of carbon deposition attached to the catalyst surface.