Abstract:
This work has been studied of the continuous column fermentor for production of ethanol. Pure culture of S. ellipsoideus was used to ferment with the pineapple juice as substrate using fermentation condition and supplement from the previous work (วิชาพงษ์, 2525) The continuous system consists of 2 parts, aerated and non-aerated columns. The aerated column is the same as in batch type while the non-aerated columns consist of series of columns. The number of the non-aerated columns used depend on the fermentation condition. To maintain the steady state of the fermentation condition the aeration rate has been studied in semicontinuous process. It was found that a suitable condition was 0.04-0.06 vvm after the 4th hours which 8% (by volume) of ethanol was obtained every 4 hours of 25% transference. Preliminary study was done on the continuous condition with dilution rate of 0.11 h⁻¹. It was found that the final ethanol concentration were 7% and 10% (by volume) with the initial ethanol concentration 2.6% and 7% (by volume), respectively, both were obtained from the column number 5 and the aeration rate of 0.5 vvm for 4 hours. This fermentation condition cannot be maintain at steady state and the system has a trend to decrease. To confirm the suitable aeration condition as studied in semicontinuous process, the dilution rate of 0.17 h⁻¹ was used with the initial ethanol concentration 7% and 9% (by volume). It was found that the final ethanol concentration were 8% and 10% (by volume) obtained from the column number 9 and 5, respectively. The best fermentation condition in this study was the dilution rate of 0.17 h⁻¹ with the aeration rate of 0.5 vvm for 4 hours, after that reduce to 0.04-0.06 vvm all the time of the fermentation. The initial ethanol concentration was 9% (by volume) and 10% (by volume) of ethanol was obtained from the column number 5.