Technology advances for continuous compression milling pretreatment of lignocellulosics for enzymatic hydrolysis

The feasibility of a continuous compression milling pretreatment process for the enzymatic hydrolysis of lignocellulosics has been demonstrated. Pretreatment efficiency was improved significantly by adjustment of feedstock moisture content prior to milling and/or increasing the roll pressure on the feedstock. Optimum moisture contents for newspaper (24%). corn stover (17%), popular (12–20%) were determined. Sugar Yields of 48% were obtained from air‐dried newspaper after six passes through even‐pressure rolls and the specific energy input was 0.21kW h/lb. The Effect of roll speed on enzymatic hydrolysis improvement was constant over a roll speed range of from 30–110 ft/min (65 rpm). Enzymatic hydrolysis results from commercial‐scale pretreatment of moist newspaper processed at 6 tons/h/ correlated well with laboratory mill data while energy consumption was 26% less.