Energy Saving For Close Boiling Mixture

Abstract

We have simulated close Boiling Mixture using Aspen Hysys 2004.2 version software. As we know separation of close boiling mixture by conventional distillation consumes lot of energy. To reduce the load on the reboiler and for energy saving as well as total annual cost saving energy efficient technologies like MVRHP, BFHP, Double effect feed forward and Feed split distillation technologies have been used for binary mixture as well as Multicomponent close boiling mixture of propane, isobutene, n-butane, C4olefins, Neopentane, Iso-pentane and n-pentane have been performed. Separation of this mixture by i-butane/n-butane fractionator requires many stages and large amount of energy to meet stringent product purity specifications. Mechanical vapor recompression heat pumps (MVRHPs) can recycle the energy of the vapor and can thus be used in such distillation processes to save steam cost and total annual cost of this separation task. Three different distillation schemes, conventional distillation, top MVRHP distillation, and bottom-flashing MVRHP distillation, were simulated for the separation of the above mixture using Aspen HYSYS software to determine the energy savings. The research result indicates that, compared to conventional distillation, energy savings for BFHP case and MVRHP case are respectively 62.65% and 57.36%. Other than this energy saving in case of double effect feed split distillation and feed forward distillation was compared with single column distillation.