晶格氧部分氧化甲烷制合成气及其氧扩散行为研究

介绍了一种在熔融盐中利用金属氧化物的晶格氧部分氧化甲烷制合成气的新方法。以NiO为氧载体对其部分氧化甲烷的氧扩散行为进行了初步研究。利用XRD和GC等分析手段,在自行设计的氧扩散行为研究反应器中对熔融盐体系和产物气进行了分析研究。结果表明,在800℃的碳酸熔融盐中,CH4通过不含NiO氧载体的熔融盐层时H2、CO浓度仅为13.67%和20%,而通过含NiO氧载体的熔融盐层时H2、CO浓度明显增至45.9%和24.5%;实验表明NiO能够提供出自身晶格氧把CH4部分氧化成n(H2)/n(CO)接近理论值2的合成气;NiO在熔融碳酸盐体系中虽有少量溶解,但主要不以离子化形式扩散氧,而是CH4与NiO分子间发生气固反应占主导,在这一过程中NiO分子中晶格氧是甲烷部分氧化的活性氧物种。

Partial Oxidation of Methane to Syngas by Lattice Oxygen and Oxygen Diffusibility Study

A new technique-partial oxidation of methane to syngas by lattice oxygen of metal oxides in molten salt is introduced.Oxygen diffusibility of NiO for partial oxidation of methane to syngas in molten salt medium system is studied through XRD and GC in a self-designed reactor.The results showed that the concentrations of H2 and CO were 13.67% and 20% when CH4 entered into molten salt without NiO,but the the concentrations of H2 and CO were 45.9% and 24.5% when CH4 entered into molten salt including NiO.The lattice oxygen could react with methane to H2 and CO,and the n(H2)/n(CO) was about 2.Although NiO could dissolve a little in molten salts,the gas-solid reaction of CH4 with NiO was the dominant reaction,and in the process the lattice oxygen was the active oxygen species for partial oxygen methane.