双螺杆物化组合预处理对秸秆产沼气的影响

为解决沼气工程实践中秸秆预处理的问题，该研究提出一种双螺杆物化组合处理途径用于秸秆的预处理。以稻草为原料，设计4组试验：双螺杆物化组合预处理组、单纯双螺杆物理预处理组、单纯化学预处理组和未预处理组，每组投料量均为干质量20 g。试验结果是：1）各组累积产气量依次为2 275.5、1 750、2 025.5和1 868.5 mL；2）单位原料产气量方差分析结果（P<0.05），化学作用P=0.0158，物理作用P=0.4828，物化交互作用P=0.0422，表明物化组合预处理效果显著；3）双螺杆疏解原料的长度在5～10 mm，宽度在0.1～0.2 mm。研究表明：双螺杆物化组合预处理是秸秆沼气原料预处理有潜力的处理手段。此外，原料形态的改变符合工程中全混式沼气池对进出料的要求，也改善了发酵池内搅拌时的流态条件。

Effect on biogas yield of straw with twin-screw extruder physical-chemical combination pretreatment

In order to solve the problem of straw pretreatment in biogas engineering, this study proposed a physical-chemical combination pretreatment of the straw based on twin-screw extruder for biogas production. Taking rice straw as the material, the experiments were divided into twin-screw physical-chemical combination pretreatment group, unique twin-screw physical pretreatment group, unique chemical pretreatment group and no pretreatment group, and the feeding amount above was 20 g by dry weight. The results of the experiments showed that: (1) the cumulative biogas yield of the four groups were 2 340.5, 1 750, 2 025.5 and 1 868.5 mL respectively; (2) the results of analysis of variance (p<0.05) on the biogas yield per gram of total solid (TS) were that: for chemical method p=0.0158, for physical method p=0.4828, for physical-chemical interaction method p=0.0422; this showed the physical-chemical combination pretreatment was significance to biogas yield; (3) after twin-screw pretreatment, the length of the material was 5-10 mm and the width was 1-2 mm. The results showed that the physical-chemical pretreatment with twin-screw extruder is one of the potential pretreatment, and the transformation in the form of the straw can meet the need of accessing and discharge for CSTR and change the flow field in the CSTR when stirring.