Thermodynamic Analysis on the Reaction of Oxidative Dehydrogenation of 1-Butene to 1, 3-Butadiene With CO2 as the Soft Oxidant

A thermodynamic study was conducted to analyze the reaction of oxidative dehydrogenation of 1-butene to 1, 3-butadiene with CO2 as the soft oxidant. The results show that the target reaction cannot occur at room temperature, but the reaction is reversible at 873.15 K (the optimum laboratory reaction temperature). The introduction of CO2 promotes the dehydrogenation of 1-butene, and the reaction can proceed through both the one-step pathway (through oxidative dehydrogenation) and the two-step pathway (direct dehydrogenation coupled with inverse water gas transformation). Moreover, it is found that the isomerization reactions are more likely to occur than the oxidative dehydrogenation reaction thermodynamically. Under the condition of free competitive reaction without catalyst, the conversion of 1-butene could reach up to 93.68%, while the 1, 3-butadiene yield could only reach to 54.64%. These findings demonstrate that the occurrence of the isomerization reactions is the cause of the low selectivity of the target reaction. Therefore, the design and development of the catalyst which inhibit the isomerization reactions will effectively improve the catalytic performance of the catalyst. © 2021, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.