Simulation And Optimization Of Synthesis Process Of Trioxane

Trioxane (trioxymethylene) is the important mid-body of POM which is a kind ofengineering plastic and other chemical products. At present, domestic productingmethods still lags behind, for example less production scale, higher materials andenergy consumption, unstable product quality, and so on. The article was about thesimulation and optimization of energy consumption and the separation of productionsduring the process.1. The article analyzed the status of the aqueous solution of formaldehyde, andused Aspen Plus software to complete the simulation of water absorption offormaldehyde with Maurer Model, and determined the theoretical number of plates andthe inlet temperature of the formaldehyde. At this point, the mass fraction offormaldehyde was63.1%.2. Preparating formaldehyde of method was methylal oxidation instead ofdirecting oxidation of methanol; the method of Methylal refining was double effectdistillation. The article was used Aspen Plus software for simulating and optimizatingabout the methylal reactor and Methylal distillation. The results showed that: in thesynthetic reaction of methylal, the best molar ratio of methanol to formaldehyde was2:1; in the production, mass fraction of methylal was99.8%.3. The article also had the simulation and analyzing in the refining process oftrioxane with extraction method and pressure swing distillation method. Bycomparison with the energy consumption to find pressure swing distillation methodwas better. The distillation column removal of methyl formate: NSTM was N=37, thefeed entrance point on the27th, minimum reflux ratio was3.5. The mass fraction oftrioxane had got with extraction method was99.8%; the swing distillation process was99.996%. The low-pressure column and high-pressure column during double-effectdistillation process energy saving rate were35%,29%respectively.In the process of synthesising trioxane, this article adopted methylal oxidationmethod instead of direct oxidation of methanol. According to this method couldimprove the concentration of formaldehyde and solve formaldehyde concentrationduring the poocess; moreover could reduce the energy consumption. Used pressureswing distillation for purifing trioxide in the process, also could greatly improve theefficiency of the column, and avoide the problem of extraction recycling.