Energy Saving Bioethanol Distillation Process with Self-heat Recuperation Technology

Abstract

Bioethanol is a renewable liquid fuel that has become established as a viable alternative to gasoline. Bioethanol is produced mainly in the US and Brazil from corn and sugarcane as feedstock, and world-wide production has been expanding. However, a distillation process is essential for refining bioethanol, which requires a large amount of heat, and thus offsets the carbon-neutral value. The energy efficiency of the distillation process with "Self-heat recuperation" technology was studied, which recovers sensible and latent heats by compressing the vapor from the top of the distillation column. In this study, the effect of energy saving in the distillation of bioethanol with self-heat recuperation technology was analyzed in comparison to the conventional counterpart using a temperature-heat diagram, as well as demonstrated on a pilot scale. Further demonstration tests were conducted for enzyme-recovering distillation that is used in the cellulosic ethanol production process from cellulosic biomass as feedstock to study the effect of energy saving using distillation with self-heat recuperation.