Over 30% of the U.S. corn crop is directed at ethanol production but market-forces and policy uncertainties represent significant challenges to this industry. As part of our efforts to develop alternative and sustainable technologies that could be readily adopted by producers, we are exploring the manufacture of acetaldehyde via enzyme catalysts. The production of acetaldehyde from ethanol via Saccharomyces cerevisiae-catalyzed dehydrogenation occurs with near perfect selectivity utilizing a cofactor, nicotinamide adenine dinucleotide (NAD). It is essential to regenerate the expensive cofactor and this presentation will provide a brief review of various methods of NAD regeneration and describe a coupled substrate approach, in which n-butyraldehyde is converted to n-butanol in 85 ± 1% conversion and a selectivity greater than 91 ± 1% at pH 8 in 3 hrs. Additionally the reaction has been demonstrated at 5% w/w ethanol, which is a representative concentration from cellulosic ethanol plants. Studies evaluating the stability of the catalytic system toward substrate and product inhibition suggests that acetaldehyde concentrations greater than 1.5% w/w inhibit performance and prompt additional research to couple product separation to reaction. Techno-economic models simulated in Aspen Plus will be described. Increasing the enzyme stability and productivity are the key requirements leading to the profitability of the enzymatic process.

Enzymatic production of acetaldehyde with coupled NAD regeneration

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.