Ethanol concentration of fermented broth by ohmic-assisted hydrodistillation

Abstract

Abstract Ohmic-assisted hydrodistillation (OAHD) as an innovative extraction method was employed to concentrate ethanol from corn beer. OAHD reduces the time and energy required for distillation of bioethanol production compared to traditional method. OAHD process was compared to traditional hydrodistillation (HD) for 3 l of 13% (v/v) beer at a constant wattage of 168 W. Test results indicate that the required energy for separation of ethanol in OAHD is 77% less than HD. Moreover, OAHD completed the distillation process in 70.6 ± 1.8 min while HD required 116.1 ± 7.8 min. The concentrations of ethanol in the final distilled product from both methods were similar (56.5% ± 1.3 for OAHD vs. 52.3% ± 4.0 for HD). Interestingly, the process control in OAHD is faster and distillation can be stopped quickly, and consequently, it will contain less unwanted distillate in comparison with HD. The findings of this study introduce OAHD as a potentially economical and environmentally friendly method for bioethanol distillation process. Industrial relevance In this research, ohmic-assisted hydrodistillation (OAHD) was used as an advanced hydrodistillation (HD) technique and compared with traditional HD in concentration of ethanol from industrial fermented corn beer. OAHD method was quicker, more economical, more sustainable and with a better ability of process control than HD method. Such advantages can make OAHD as an alternative technique for the production of larger quantities and higher concentrations of ethanol by scaling up the equipments and process in biofuel factories, instead of the conventional HD process.