Heat pump assisted divided wall column for ethanol azeotropic purification

Extractive Dividing Wall Column for Separating Azeotropic Systems: A Review

“…4,57 The goal of a heat pump is to decrease TAC by lowering the utilities cost even with the additional cost of the heat pump. 4,57,58 Intermediate heating can involve either preheating the feed and entrainer feed steams or installing an intermediate reboiler on the right-hand side of a traditional EDWC, as shown in Figure 7. The intermediate reboiler would use a combination of low-pressure steam and heat from the recycling entrainer stream.…”

“…1−3 Distillation is a reliable technique, but it is very energy-intensive accounting for 40% of the chemical industry energy consumption and consuming 3% of the world's energy. 1,4 This energy is generated primarily from fossil fuels and therefore emits large amounts of carbon dioxide. Along with the large energy demand, distillation has a thermal efficiency of only 5%−20%.…”

“…Separating chemicals is a core technique within the chemical, petroleum, and pharmaceutical industries, with distillation being the most common separation technique accounting for 95% of fluid separation. − Distillation is a reliable technique, but it is very energy-intensive accounting for 40% of the chemical industry energy consumption and consuming 3% of the world’s energy. , This energy is generated primarily from fossil fuels and therefore emits large amounts of carbon dioxide. Along with the large energy demand, distillation has a thermal efficiency of only 5%–20%. − Because the future of the chemical and pharmaceutical industry is targeted toward a more environmentally conscious process, distillation energy demand must be improved.…”

“…The DWC has lower energy demand and capital cost and a smaller plant footprint while still maintaining the product purities that conventional distillation would obtain. It has been shown that DWCs can decrease the capital cost by 30% and the operating cost by 40%. ,, The energy savings are around 30%, and the plant space saved is 40%. − DWCs are typically used to separate ternary, nonazeotropic hydrocarbon systems . The first industrial DWC was implemented in 1985 by BASF, with more companies following suit and implementing their own DWC units. , As of 2010, there were 100 DWCs in operation.…”

“…The solvent recovery step in the second column uses a large amount of energy. By having the ED process combine with DWC to form an extractive dividing wall column (EDWC), the amount of energy needed for the solvent recovery step will decrease as will the overall economics and energy costs. , …”