Distillation has long been used as the separation process in the chemical and petroleum industries because of its reliability, simplicity, and low-capital cost. It is employed to separate benzene from toluene, methanol or ethanol from water, acetone from acetic acid, and many multicomponent mixtures. Fractionation of crude oil and the production of deuterium also rely on distillation.
Today, with 40,000 distillation towers in operation, distillation makes about 95% of all current industrial separation processes; however, distillation systems also have relatively high energy consumption. Significant effort, therefore, has been made to reduce the energy consumption and to improve the efficiency in distillation systems. This includes incorporating new analytical sensors and reliable hardware into the system to achieve advanced process control, using heat rejected from a condenser of one column to reboil other columns, and coupling other advanced process such as adsorption and crystallization with distillation to form energy-saving hybrid operation systems.