The study on exhaust gas recycling process of n-butane oxidation to MA：

• 1、Wuhan University of Science and Technology, School of Chemistry and Chemical Engineering, Wuhan, 430065
• 2、Zhejiang University, College of Chemical and Biological Engineering, Hangzhou, 310024

Abstract：In this paper, the reaction kinetics of n-butane oxidation to maleic anhydride on the domestic FVO-1 VPO was studied and the corresponding kinetic model was developed based on the separately considered CO and CO2 double-triangle reaction network. It is found that the present model can accurately predict the product contents including CO and CO2 via statistical tests and comparison of model predicted results and experiment results. A high flux exhaust gas recycling technology has been developed aiming at MA synthesizer with air as oxidizer and high n-butane conversion. Aspen plus is applied to study the recycling process combined with the model proposed. The study shows that after recycling 40% exhaust gas, n-butane consumption decreases by 5.7% with the same MA production maintained. However, the recycling of exhaust gas is not infinite and it is restricted to the temperature sensitive of catalyst. With the increasing amount of exhaust gas, lower limiting values of explosion limits of n-butane gas mixture tend to increase which is beneficial to the safe operation according to Le Chatelier's principle.

Keywords： chemical reaction engineering n-butane MA VPO catalyst exhaust gas recycling process simulation