Catalytic Oxidative Conversion of Ethane to Ethylene. Development of a Process Technology
Current industrial processes for ethylene production are based on highly energyintensive steam cracking or catalytic dehydrogenation of hydrocarbon feedstock at temperature more then 850 °C yielding ethylene 25-30 % from naphtha and at about 50 % from C2-C4 alkanes. The goal of the present study is development of the basis for generation a new catalytic technology for ethylene production from ethane. Therein we report the data on the catalyst optimization, reaction kinetics and reactor modeling as well. Various oxide catalysts on the base of molybdenum and vanadium have been used. As the catalyst composition become more complex – from individual oxides to the binary ones and mixed VMoTeNbO eventually, ethylene yield increases approaching the acceptable for commercial application value – no less then 70 %. Kinetic study allows specifying the impact of reaction conditions on catalytic performance. Longevity test during 500 h at 400 °C in reaction mixture 15 % vol. C2H6 in air have confirmed the stability of the catalyst developed. Within 360-450 °C temperature was determined does not affect the selectivity to reaction products at the equal value of ethane conversion. Therefore, multi-tubular reactor was chosen to implementation the process of oxidative dehydrogenation ethane on VMoTeNbO catalyst. The characteristics and process parameters for industrial tubular fixed bed reactor for ethylene production from ethane at capacity of 1,000 TPA are determined by using the two-dimensional pseudo-homogeneous mathematical model. Thus, the process developed is capable of ensuring high ethane conversion at temperature lower 450 °C together with high selectivity to ethylene and in doing so it causes the significant reduction of energy consumption and increase an efficiency of the process in whole.