Steam pretreatment of lignocellulosic material for enhanced enzymatic hydrolysis - Lab scale studies and pilot scale application

Pressure, temperature, and retention time are the most studied parameters in steam explosion pretreatment. However, this work aimed to fix these parameters and to evaluate the influences of less investigated scales on the saccharification yield in hydrolysis. In this study, firstly, mixed hardwood samples smaller than 5 ㎝ were treated with steam explosion at 225 ℃ for 5 min. The variable parameters were biomass loading, and scale. Steam-exploded samples were hydrolyzed with the enzyme for saccharification for 72 h. The sugar content of the resultant products was analyzed to estimate the yield of sugars (such as glucose, xylose, galactose, mannose, and arabinose). The best glucose yield in the steam exploded mixed hardwood was achieved with 0.2 ㎏ of the sample, the pressure of 25 ㎏f, and lab scale. These conditions gave a glucose yield of 85.8% in the steam exploded mixed hardwood. Although steam explosion-treated mixed hardwood exhibited a higher glucose content at the lab scale, the difference was statistically insignificant (p>0.05; approximately 1.2 times). Therfore, the pilot scale is suggested as suitable for the industrial production of steam explosion-treated mixed hardwood.