餐厨垃圾两相厌氧消化小试工艺研究

Bench Scale Study of Methane Production from Food Waste in Combined Two-Stage Process

摘要: 本文以餐厨垃圾为原料，利用两相厌氧消化装置开展了厌氧消化工艺的实验研究。实验建立了四个进料浓度梯度，通过逐步提高进料料浆的浓度，研究了在不同进料负荷率情况下，厌氧消化系统的变化趋势，分析了进料负荷率与挥发性脂肪酸、氨氮浓度的变化关系。实验发现，当酸化相有机负荷率为22.65kgVS/m³•d，甲烷相有机负荷率为6.25kg VS/m³•d时，单位产气率最佳，可到0.551m³/kgVS。实验发现，当有机负荷率从2.97上升至8.15kgTS/m³•d时，虽然单位产气率出现下降，但是厌氧系统的容积产甲烷率从1.61上升到3.91m³/m³•d。这对于商业运行的餐厨垃圾厌氧消化工程而言，容积产气率的上升，提高了每日进场餐厨垃圾的总量，增加了每日的沼气绝对产量，提升了沼气发电量或者提纯后天然气的总量，对项目的经济性有明显的改善。

Abstract: To investigate the fermentation features of food waste at different loading rates, a lab scale fer-mentation process for the anaerobic treatment of food waste was carried out with a two phase bioreactor. The experiment set up four step-wisely increased loading rates, the effects of volatile fatty acid, ammonia nitrogen, retention time and loading rates on fermentation process were studied. At the organic loading rate of 22.65 kg VS/m³•d in hydrolysis reactor and 6.25 kg VS/m³•d in methane reactor, specific methane yield of 0.551 m³/kg VS is achieved. The research shows that the specific methane yields declined when organic loading rates increased from 2.97 to 8.15 kg TS/m³•d, but the volume biogas production rate increased from 1.61 to 3.91 m3/m³•d.With regarding to commercial food waste anaerobic digestion project, higher volume biogas production rate means more biogas production and more economic profits.