刈割时间对杂交狼尾草成分及厌氧发酵性能影响试验

Effect of Growth Stages on Performance of Anaerobic Digestion and Physico-chemical Properties of Pennisetum Hybrid

以杂交狼尾草为原料，采用批式中温厌氧发酵工艺，研究生长期为30、60、91、128、175d的杂交狼尾草的成分及厌氧发酵沼气产量。研究结果表明：刈割时间对原料成分有较大的影响，原料中C质量分数、碳氮比，干物质（Ts）、挥发性固体物（Vs）和木质素的质量分数随着刈割时间的延长呈升高的趋势。杂交狼尾草在单位土地面积上的干物质产量随刈割时间的延长先增加而后降低，其中生长128d时刈割干物质产量最高，可达15．01t／hm^2。原料的产气率也随刈割时间的延长先升高而后降低，其中生长60d的杂交狼尾草的产气性能最高，其挥发性固体物的产气率和产甲烷率分别为0．68、0．37L／g。综合干物质产量和原料产气率，杂交狼尾草在不同刈割时间下单位面积土地上的生物质量可产沼气量为848．07～6279．73m。／hm^2，相应的年产能为165．49～292．66GJ，可见杂交狼尾草是一种有潜力的厌氧发酵原料。

The effects of growth stages on the physico-chemical properties and anaerobic digestion performance of Pennisetum hybrid were studied in batch mesophilic experiments. The results indicated that the content of C,TS, VS and lignin increase over time at different growth stages. The dry matter yield per hectare firstly increases then declines, with the highest dry matter of 15.01 t/hm2. Biogas production performance of Pennisetum hybrid firstly increases and then deceases, and the maximum biogas yield is obtained when Pennisetum hybrid is harvested at 60 d growth stage, which are 0.68 L biogas/g VS and 0. 37 L methane/g VS. Based on the biomass yield per hectare and biogas production of Pennisetum hybrid, the area specific biogas yields of 848.07 - 6 279.73 m3/hm2 can be achieved from the Pennisetum hybrid harvested at different growth stage, the corresponding energy production of 165.49 292.66 GJ per year. Biogas production from Pennisetum hybrid suggests that the energy grass is a potential material for anaerobic digestion.