马铃薯茎叶青贮时间对厌氧发酵产沼气性能的影响

Effect of Silage Time on Anaerobic Biogas Production of Potato Vines

为提高农业废弃物能源化利用率,保障沼气工程原料长期供给,该研究探讨了青贮时间对马铃薯茎叶成分、品质及厌氧发酵产沼气特性的不同影响。研究结果显示:除粗蛋白和粗脂肪含量小幅波动外,青贮过程中马铃薯茎叶挥发性固体、可溶性碳水化合物、中性洗涤纤维等有机成分指标均逐渐下降;30~180 d青贮周期内,pH值始终维持在4.10~4.40,乳酸含量30 g·kg^-1以上,乙酸含量、氨氮/总氮比值均较低,丁酸无检出,青贮品质良好。以青贮30 d,60 d,120 d,180 d马铃薯茎叶为原料进行厌氧发酵,发酵前期酸化更快,产气启动更迅速,后期酸碱更平衡,累积产气量分别提高7.88%,18.03%,25.56%和26.11%,最高甲烷浓度提高5.36%~8.59%。添加0.2%丙酸条件下对马铃薯茎叶进行30~180 d的青贮,可显著提高其厌氧发酵产沼气性能。

In order to improve the efficiency of energy utilization of agricultural waste,and guarantee the long-term supply of raw materials for biogas projects,in this paper,effects of silage time on potato vine composition,quality and its anaerobic biogas production were studied.The results showed that,in the process of silage,organic components such as volatile solid,water soluble carbohydrate and neutral detergent fiber of potato vines decreased gradually,while crude protein and crude fat content fluctuated slightly.Within the silage period of 30~180 d,the pH value was always maintained at 4.10~4.40,and the lactic acid content was above 30 g·kg^-1,the acetic acid content and the ammonia nitrogen/total nitrogen ratio were relatively low,butyric acid was not detected,thus the silage was of good quality.The potato vines silaged for 30,60,120 and 180 days were used as raw materials for anaerobic fermentation respectively.Comparing with the control,the acidification was faster in the early stage of fermentation,the biogas production started more quickly,the acid and alkali were more balanced in the later stage of fermentation,the cumulative gas production increased by 7.88%,18.03%,25.56%and 26.11%respectively,and the maximum methane concentration increased by 5.36%~8.59%.In conclusion,with the addition of 0.2%propionic acid and silage for 30~180 d,the biogas production performance of potato vines could be significantly improved.