초록 |
Pretreatment is one of the necessary elements in the biomass-to-chemicals conversion process. The primary purpose of pretreatment is to make the cellulosic biomass amenable to the action of the cellulase enzyme. An ideal pretreatment should fractionate the biomass into three main streams: cellulose, hemicellulose, and lignin. A two-temperature dilute acid process(DA) and an ammonia recycled percolation(ARP) as the pretreatment of biomass feedstocks have been investigated. The main technical features of percolation is a packed-bed flow-through-type (percolation) reactor is operated under a recirculation mode. In biomass pretreatment, a percolation process offers a unique advantage in that the lignin and other extraneous components are separated from the biomass structure. In an attempt to increase the fractionation, combined pretreatment methods were investigated. The overall combined ARP-DA reaction removed 100% of the hemicellulose and 76% of the lignin, while leaving 74% of the cellulose in the solid. An analysis of the liquid portion showed that nearly all of the solubilized cellulose was conserved in the liquid rather than being decomposed. |