Design and Control of Various Etherification Processes of Glycerol and Isobutene

Nowadays, due to the increasing biodiesel production, large amounts of glycerol are available at low cost. The development of new process routes for alternative uses of glycerol has gained a lot of attention in recent years. This work studies the process design and control issues about glycerol etherification with isobutene to produce glycerol tertiary butyl ethers. The diether and triether products can be used as an octane booster for gasoline or as diesel additive. The conventional process for etherification of glycerol with isobutene first proposed by Behr and Obendorf (2002) is short of complete feasibility and simulation analysis. According to the design concept of Behr et al. (2008), Cheng et al. (2011) have first carried out the optimal flowsheet of the conventional etherification process. Moreover, they present an improved etherification process with lower total cost and higher selectivity. It is known reactive distillation (RD) can effectively combine catalytic reaction and separation in a single unit and truly offer significant advantages such as high conversion, selectivity improvements, reduced energy use and simple operation. Recently RD has received considerable attention due to its significant benefits and potential applications over traditional processes. The RD process for etherification of glycerol with isobutene first proposed by Vlad et al. (2011) is also short of complete feasibility and simulation analysis. In this work, by replacing the flash with a stripper, a modified reactive distillation etherification process has been developed to meet the required product specification. By minimizing the total annual cost, the results of economic evaluation and control analysis show that the proposed reactive distillation process has almost 50% lower total cost than the optimal design of the improved process.

Project ID:PB10608-3598
External Project ID:MOST106-2221-E182-055