Distillation has long been the go-to separation method in chemical process industries and small fuel alcohol plants alike, serving as an efficient separation technique that requires no special training to design directly. While its popularity remains undiminished by climate change concerns, industrial designers are searching for more energy-efficient separation techniques.
The greatest strides have been taken with the advent of process intensification technologies like reactive distillation, dividing wall columns and hybrid processes – these provide significantly better separation energy performance than traditional column interiors such as trays or packed columns.
Reactive distillation made its debut during the 1990’s when Eastman-Kodak’s high-purity methyl acetate process adopted it to operate more quickly with lower reflux ratio and shorter operation times. Now, most commercial process simulators, including AspenPlus and gPROMS Process incorporate this technology.
Distillation columns equipped with dividing walls enable liquid and vapor phases to be more effectively directed along their paths for maximum energy efficiency, saving over 20% in energy costs while being easier to clean than traditional plate-type columns. This has been demonstrated through laboratory studies.
Distillation will likely remain the primary method for small-scale fuel alcohol plants in the future, although the industry must work toward improving energy efficiency, and considering new sources of heating aside from fossil fuels.