Abstract:

The process of producing 40 000 t/a benzene anhydride with o-xylene by means of Aspen software was simulated, and the simulation results were analyzed. Cis-butendioic anhydride, benzoic acid and phthalide in light fraction column T201 were removed on the column top, the overhead component: benezene anhydride 25.74%, cis-butendioic anhydride 39.11%,  benzoic acid 25.37%, phthalide 9.78%. For product column T202 top, except that very small amount of benzoic acid and  phthalide were contained, the rest was benzene anhydride, the column bottom was heavy component, which can meet the separation requirement. In actual production, benzene anhydride content in light fraction was about 50%, therefore the reflux ratio in production operation can be enlarged, which can optimize the operation.