Performance of oscillatory flow reactor and stir tank reactor in solvent fermentation from palm oil mill effluent

Abstract

Advance in mixing technology has developed a new way of mixing fluids by introducing an oscillatory motion to replace the conventional mechanical agitation or an air bubble displacement. This new way of mixing breakthrough has been implemented in an Oscillatory Flow Reactor (OFR). This research will be focus on the performance of OFR as a bioreactor by comparing with Stir Tank Reactor (STR), which is the traditional device in fermentation. The experimental work was conducted in an OFR and a STR with a working volume of 1.5 l. Solvent production strain, Clostridium acetobutylicum NCIMB 13357 was grown in OFR and STR, using fresh Palm Oil Mill Effluent (POME) as growth medium. All of the experiments were conducted anaerobically under batch mode for 72 hours at constant temperature of 35°C. Comparisons of the growth trend and solvent fermentation performance for both devices were investigated. Total solvents (acetone, butanol and ethanol) produced in an OFR was comparable with that of STR. Total solvents production in OFR is 1.8 times higher than that of STR resulted in total 1.6 g/l of solvents. The results of this investigation showed that OFR has an excellent potential as an alternative device in fermentation processes.