Profit maximization of the normal hexane recovery process through a thermal integration method

• Published in: The Korean journal of chemical engineering 2012, 29(9), 150, pp.1239-1245
• Main Authors: Kim, Hye-Ran, Kim, Dong Sun, Cho, Jungho
• Format: Article
• Language: English
• Subjects: Biotechnology; Catalysis; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Materials Science; Separation Technology; Thermodynamics; 화학공학
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-011-0296-x

We developed a separation process that can minimize utility consumption in order to obtain normal hexane from crude raffinates for electronic-grade reagents. For the separation of normal hexane from the crude raffinate mixtures, a two-column configuration was selected. The first distillation column removes lighter constituents than normal hexane as a column top product, after which heavier constituents containing normal hexane are put into the middle of the second distillation column. This allows normal hexane with a purity of 95.5 wt% to be obtained from the top of the second distillation column by removing the constituents that are heavier than normal hexane as a second column bottom product. When both distillation columns are operated at approximately atmospheric pressure, it requires about 5.2 tons of steam per hour both for the reboiling heating source. However, when the operating pressure of the second distillation column is increased, the vapor stream coming out of the top of the second distillation column can be used as a heating medium for the reboiling source of the first distillation column. In this way, steam of only 3.1 tons per hour is required, potentially reducing the amount of steam used to 59.6% of the original amount.