High-purity DMC Production by Indirect Alcoholysis of Urea:Optimal Design and Control

摘要

This work shows that it is feasible to convert a greenhouse gas to a green solvent.Dimethyl carbonate(DMC)is an eco-friendly chemical compound which can be obtained by indirect alcoholysis of urea with propylene glycol,followed be the trans-esterification of propylene carbonate(PC)with a large excess of methanol.However,this process route requires the energy-intensive separation of the DMC-methanol azeotrope.Here,we propose a new process in which the transesterification reaction is performed with excess of PC,which allows obtaining high purity DMC(99.8%wt)in a less complex process.By optimizing the new process,the total annual cost is minimized to 4.71 M$/year(for a production capacity of 32 ktpy DMC),and by heat integration the energy requirement is reduced to only 2.64 kWh/kg DMC.The dynamics and control of the process show that ±10% changes of the production are easily accommodated.