(690d) Minimizing Enzyme Inhibition through in-Situ Recyclable Ammonia Detoxification of the Whole Slurry Derived from Acid-Catalyzed Pretreatment of Lignocellulosic Biomass

Acid-catalyzed pretreatment has been commonly used to break down the cell wall structure of lignocellulosic biomass and enhance the accessibility of cellulose, while it generates various soluble compounds in the pretreated whole slurry that are strongly inhibitory to the enzymatic cellulose hydrolysis. Although many previous studies have reported various detoxification strategies to minimize the inhibitory effect of the water-soluble compounds on the cellulose hydrolysis, many of these strategies needs excessive amount of chemicals or adsorbents as well as additional solid-liquid separation step. In order to mitigate the enzyme inhibition and achieve high concentration of fermentable sugars, it is desirable to develop a facile and economically viable approach to alleviate the enzyme inhibition caused by pretreatment-derived inhibitors. In this study, a novel in-situ recyclable ammonia detoxification (RAD) has been applied to alleviate the enzyme inhibition. By applying RAD directly to the pretreated whole slurry, a significantly improved cellulose hydrolysis was achieved at relatively low enzyme loadings, while no solid-liquid separation step was involved. This presentation will show how such strategy could help to minimize the enzyme inhibition during enzymatic hydrolysis of the pretreated whole slurry. The effects of detoxification conditions on the toxicity of the soluble compounds, the total sugar recovery and the hydrolyzability of pretreated biomass were systematically assessed. In addition, the detoxification mechanism of RAD was illustrated and an economical analysis was presented to suggest its potential application in the biorefinery process.