Categories and characteristics of organic wastes As mentioned

According to the structure of lignocellulosic material, high-strength lignin, like in the outer membrane of the plants, exists to protect the morphology of the plant. However, for utilization of the lignocellulosic material, high-strength lignin structures play a role of barriers in the conversion of LY2409881 and hemicellulose. And, most conversion processes have employed cellulose and hemicelluloses as substrate. Therefore, pretreatment is a necessary and important process for this conversion. Some research indicated that pretreatment took up more than one third of the whole cost of process [41]. With the wide application of lignocellulose in industrial biorefineries, improvement and development of the pretreatment process is still a hotspot in recent research. The main targets are trying to decrease the processing costs, or to find a suitable pretreatment process continuously which can remove lignin. The main achievements of recent researches into the pretreatment process were described in Table 3. The pretreatment technology has been developed from single physical methods, chemical methods or biological methods, to complex methods based on the composition of the raw materials. Complex pretreatment can obtain a better quantity of cellulose by removing lignin more completely, but the costs still need to be decreased by simplification of the whole process [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52] and [53]. Some studies even established the feasibility of using an electron beam or protein beam in lignocellulose pretreatment, which can save time in the pretreatment process [42] and [44]. With the stable composition of crops and forest products and the developed pretreatment technologies, these kinds of organic wastes have received high attention for applications in an industrial scale [45], [46], [47], [48], [49], [50], [51], [52], [53], [54] and [55]. In some countries in South America, and even the U.S., methods for utilizing the organic waste from agricultural residues have already been designed, and applied in industrial biorefieneries [4].