Recovery of butanol from fermentation broth by gas stripping

This is an overview of the butanol (usually called acetone butanol ethanol, ABE) fermentation in various types of reactor systems and recovery by gas stripping. Gas stripping is a simple technique which does not require expen sive apparatus, does not harm the culture, does not remove nutrients and re action intermediates and reduces butanol toxicity (inhibition). As a result of butanol removal by gas stripping, concentrated sugar solutions can be u sed to produce butanol/ABE. Compared to sugar utilization of 30 gl(-1) in a control batch reactor, sugar utilization of 199 gl(-1) has been reported w ith 69.7 gl(-1) solvent production. In fed-batch reactors concentrated suga r solutions (350 gl(-1)) have been used. Additionally, the process of ABE p roduction results in concentrated product streams containing 9.1-120 gl(-1) butanol/ABE. In the integrated ABE production and recovery systems, select ivities of 4-30.5 have been reported. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.