Location: Functional Foods ResearchTitle: Recovery of butanol by counter-current carbon dioxide fractionation with its potential application to butanol fermentation
Submitted to: Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2016
Publication Date: 6/30/2016
Publication URL: http://handle.nal.usda.gov/10113/5642492
Citation: Solana, M., Qureshi, N., Bertucco, A., Eller, F. 2016. Recovery of butanol by counter-current carbon dioxide fractionation with its potential application to butanol fermentation. Materials. 9(7):530-540.
Interpretive Summary: This research studied the use of counter-current carbon dioxide fractionation as a means to separate butanol from a mixture with water. Several factors which could influence the separation, including solvent-to-feed ratio, temperature, pressure, and feed solution composition were investigated. The effects of these factors on separation efficiency, butanol removal rate, total removal and butanol concentration in the extract were measured after the extraction. Starting with a feed solution of 20 g L-1, the highest separation efficiency was obtained at 35°C and 10.34 MPa at a solvent-to-feed of 2.5. Under these conditions, 92.3 % of the butanol present in the feed solution was removed giving a concentration of 787.5 g l-1 of butanol in the extract. The results obtained in this study demonstrate the potential of counter-current CO2 fractionation as an alternative method to recover butanol from butanol fermentation broths.
Technical Abstract: A counter-current CO2 fractionation method was studied as a means to recover butanol (also known as 1-butanol or n-butanol) and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating parameters, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally investigated in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. Results show that the highest separation efficiency (351.5) is obtained at 35 °C and 10.34 MPa, with a removal rate of 0.0011 kg h-1. At these operating conditions, 92.3 % of the butanol present in the feed solution was removed and a concentration of 787.5 g l-1 of butanol in the extract was obtained, starting from a feed solution of 20 g L-1. Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was obtained in the water rich fraction (raffinate) whereas the highest concentration of acetone was found in the butanol rich fraction (extract).