Stalk is heterogeneous, the same as its conversion property. According to the het­erogeneous characteristics of stalk, three platforms have been set up including low pressure, non-pollution steam explosion platform, solid-state fermentation platform and solid enzyme hydrolysis, fermentation, and separation coupling platform. For each platform, pilot test apparatus are designed, as well as industrial equipment. By process integration, multi-layered stalk refining has been established and indus­trialized in plant about ethanol, sheet, spinning. Especially, in September, 2010, Laihe Chemcial Co., Ltd., located in Jilin Province, China introduced this integrated process (Fig. 4.4 and 4.5). Steam explosion-alkali extraction-mechanical carding integrated pretreatment is applied. Its capacity is 300 thousand tons corn stalk annu­ally. The products from this technology are 50 thousand tons butanol, acetone, and

ethanol, 30 thousand tons pure lignin which could be converted into 20 thousand tons phenol formaldehyde resin adhesive, 120 thousand tons cellulose which could be converted into 50 thousand tons biological polyether polyol. The cost of solvent products reduce more than 50 % after cost apportion by lignin and cellulose. Many other stalk refining plants are also on the way.

Cost apportion Cost Multiple products oriented model Single product oriented model