DESIGN AND CONTROL OF POLY(OXYMETHYLENE) DIMETHYL ETHERS PRODUCTION PROCESS DIRECTLY FROM FORMALDEHYDE AND METHANOL IN AQUEOUS SOLUTIONS

摘要

Poly(oxymethylene) dimethyl ethers (OME) are widely used in the reduction of soot formation in diesel engines, and also as physical solvents for absorbing carbon dioxide from natural gas. In this work, a new production process of OME is designed and rigorously studied. In the conventional process, multiple process sections are required to first separately produce trioxane and methylal, and then to react of these two intermediates to produce OME. In this paper, the plant-wide process via a much simply direct synthesis of OME from formaldehyde and methanol in aqueous solutions is newly developed. The overall process includes an upstream section and a downstream product purification section. After the steady-state simulation of the process is established, the process flowsheet is optimized by minimizing total annual cost (TAC). The dynamics and control of the proposed OME production process is also investigated in this study. A proper control strategy is developed for the optimized process to reject the process disturbances.