The conversion of xylan to xylitol is commonly realized via the two separate process steps hydrolysis and hydrogenation (or fermentation). Recent research activities aim at developing one-pot processes to facilitate this conversion to save resources and operation time. To avoid hazardous chemicals like liquid acids for the initial xylan hydrolysis, enzymes are a suitable green alternative. A series of experiments are discussed wherein process conditions for chemical conversion were adjusted to more enzyme-friendly reaction conditions to overcome xylose-induced product inhibition by direct hydrogenation of sugar to xylitol. A novel combination of enzymes and precious metal catalyst (Ru/C) in an one-pot process is demonstrated. Based on these results, limiting factors and potentially advantageous process parameters as well as catalyst combinations are discussed.
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