Separation of Aqueous Solutions By Sustainable Hybrid Process Design

Separation of Aqueous Solutions by Sustainable Hybrid Process Design

Nooshin Shahlari BS. Chemical Engineering University of Kansas ; Kyle V. Camarda PhD. University of Kansas, Lawrence, KS 66045; Rafiqul Gani PhD. Technical University of Denmark, S¿ltofts Plads Lyngby

Abstract

            Distillation is an extremely energy intensive process, consuming about 10-15% of the worldÕs energy consumption. The rise of carbon dioxide in the atmosphere leads to the greenhouse effect, which traps the sunÕs energy on earth and results in an overall temperature increase. 90% of separation processes energy in the chemical and petroleum industries, which results in a large carbon footprint.² Replacement of energy intensive distillation processes with a hybrid membrane-distillation processes is proposed for aqueous separations in this paper to improve the energy efficiency the large energy consumption and greenhouse gas emissions. Three sets of aqueous separation systems simulated using Pro II, comparing traditional distillation with hybrid membrane distillation systems. Results show that an energy and CO₂ savings of 95% for acetic acid/water solutions are possible, 92% for acetone/water, while 42% for methanol/water with the hybrid systems. For the three separations investigated, the payback period for small scale systems was 0.13, 0.07, and 0.53 years respectively. A hybrid distillation process decreases energy usage by 63-99% to reach purities of 90-99.5% in these aqueous mixtures. This study showed that hybrid membrane distillation systems are economically attractive for important industrial separations.

Sources

1.     Sholl, D. S., & Lively, R. P. (2016). Seven chemical separations to change the world. Nature, 532(7600), 435-437. doi:10.1038/532435a

2.     Oak Ridge National Laboratory. Materials for Separation Technologies: Energy and Emission Reduction Opportunities (2005).