Acetone-butanol-ethanol (ABE) fermentation of soluble and hydrolyzed sugars in apple pomace by Clostridium beijerinckii P260

Authors: JIN, QING - Virginia Polytechnic Institution & State University; Qureshi, Nasib; WANG, HENGJIAN - Virginia Polytechnic Institution & State University; HUANG, HAIBO - Virginia Polytechnic Institution & State University

Submitted to: Fuel
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2019
Publication Date: 1/30/2019
Citation: Jin, Q., Qureshi, N., Wang, H., Huang, H. 2019. Acetone-butanol-ethanol (ABE) fermentation of soluble and hydrolyzed sugars in apple pomace by Clostridium beijerinckii P260. Fuel. 244:536-544. https://doi.org/10.1016/j.fuel.2019.01.177.
DOI: https://doi.org/10.1016/j.fuel.2019.01.177

Interpretive Summary: Butanol, a superior biofuel than ethanol, contains 33% higher energy and burns cleaner. It can be used in gasoline in any proportion. Butanol can be produced from corn, and molasses. However, higher prices of these feedstocks make butanol production costly. For this reason, we focused its production from apple pomace, a feedstock that is inexpensive and readily available. In 2015 approximately 70 million metric tons of apples were produced in the United States of which 30% were industrially processed to produce juice, cider or puree which generated large amounts of pulp, skin, and seed wastes called pomace. We used apple pomace to produce butanol as this feedstock (apple pomace) is economically available. We were successful producing 203-262 g of acetone butanol ethanol (ABE), of which butanol was the main product, from 1 kg of dried apple pomace. Development of butanol or ABE production from this feedstock is expected to improve apple growers’ economy, create employment opportunities, and benefit automobile industry.

Technical Abstract: The decreasing supply of fossil fuels and increasing environmental concern of food waste disposal have raised interests in food waste conversation to biofuels such as butanol. Apple pomace, a food processing waste rich in carbohydrates, is a good candidate for butanol production. The goal of this study is to thoroughly convert apple pomace water soluble sugars (WSS) and hydrolyzed sugars from structural carbohydrates to acetone-butanol-ethanol (ABE) by fermentation. WSS was extracted from apple pomace by hot water. The solid residue was pretreated with acid or alkali followed by enzymatic hydrolysis to obtain acid hydrolyzed sugars (ACHS) or alkali hydrolyzed sugars (ALHS). Finally, WSS, ACHS, and ALHS were mixed to produce acetone-butanol-ethanol (ABE) by Clostridium beijerinckii. As a result, a total of 202.8, 260.1, and 262.2 g of ABE were obtained from each kg of dry apple pomace using WSS, WSS+ACHS, WSS+ALHS as the substrates, respectively, based on the mass balance.