Water transfer in steam explosion process of corn stalk

Steam explosion is one of the leading and most promising biorefinery technologies for lignocellulosic biomass. Water as the only transfer medium participated in steam explosion process is closely correlated with refining efficacy and energy consumption, while researches on steam explosion are neglected from transfer mechanism. In this work, from water transfer perspective, steam explosion process was innovatively divided into four specific stages and the multi-stage mass transfer model of steam explosion process was firstly established. From this model, quantitative relation of water composition in each stage and final water content formula were evaluated, which is efficient to guide the process energy efficiency with several proposed regulation strategies. By combining transfer process simulation with pretreatment efficacy evaluation, much water in feedstock presented a buffering effect on reaction and transfer issues during steam explosion process, thereby weakening the actual severity of treatment. 40% water content of cellulosic biomass was optimized from the compromise between treatment efficacy and energy efficiency. The yield of overall glucose through pretreatment and enzymatic hydrolysis was increased by over 20% with a potential cost savings of steam consumption by simply coordinating water content of cellulosic biomass prior to steam explosion treatment. Thus, results in the work emphasize the water transfer and regulation during steam explosion process on understanding water reaction mechanism, enhancing pretreatment efficacy and saving energy, leading to more efficient use of biomass. (C) 2015 Elsevier B.V. All rights reserved