Ethanol Production from Date Syrup: Continuous Ethanol Fermentation Using Flocculent Yeast

The present investigation deals with continuous ethanol production from date syrup by using a flocculent yeast. The main portion of the system consisted of a jacketed cylindrical Pyrex glass bioreactor where the date syrup was pumped from its base and the product was received from the top. Box-Wilson composite rotatable design was constructed to obtain the proper conditions of ethanol fermentation [temperature, date syrup concentration and feeding flow rate]. It is possible to obtain from this technique a polynomial equation which describes how these variables affect ethanol production. The optimum conditions are: Temperature: 29.5º C, Date syrup concentration: 64.47 mg/cm3, Feeding flow rate: 200 cm3/hr. The study shows that flocculent yeast is more efficient in continuous ethanol production process when it is compared with non-flocculent yeast. Flocculent yeast cells are able to aggregate and make flocs so that, the cells will remain in the column. Date syrup was used in this research as a sugar substrate because it was the available sugar source in Iraq and usually used in ethanol production. Maximum conversion of date syrup to ethanol is 92.99%.