汽爆预处理对互花米草厌氧发酵产气特性的影响

Effect of steam explosion pretreatment on biogas production characteristics of anaerobic fermentation of Spartina Alterniflora

针对互花米草厌氧发酵过程存在的结构抑制问题,采用高速汽爆设备,在1.5,2.0,3.0MPa条件下分别对其进行蒸汽爆破预处理试验,并采用揉搓处理作为对照.厌氧发酵试验结果表明,随汽爆压力的增加,累积产气率呈下降趋势,1.5,2.0,3.0MPa处理原料的单位挥发性固体(VS)累积产气量分别为293.6,176.1,145.4mL/g,对照为238.7mL/g.经2.0,3.0MPa处理的原料在发酵过程中存在酸积累现象,挥发性有机酸(VFA)中乙酸最高达10599.42mg/L,丙酸浓度高于1000mg/L,这是导致这2组原料累积产气量低于对照的主要原因.

Aming at resolving the structural inhibition of Spartina alterniflora on its anaerobic digestion, experiments were performed for investigating effects of steam explosion pretreatment by a high-speed steam explosion equipment under 1.5, 2.0 and 3.0MPa pressure on biogas yields, and rubbing treatment was used as control. Anaerobic digestibility and biogas yield of S. alterniflora were evaluated by anaerobic batch digestion experiments. With the increase of steam explosion pressure, the cumulative biogas yield declined. The maxium cumulative biogas yield of 293mL/g VS was obtained at 1.5MPa after 55 days of digestion, which was the double of that at 3.0MPa. The cumulative biogas yield of S. alterniflora by rubbing treatment was 239 mL/gVS, which was much more than that of the 2.0 and 3.0MPa treatments. The acidogenic rate of 2.0 and 3.0MPa treatments were fast than that of 1.5MPa treatment and caused VFA accumulation. Propionic acid concentration of 2.0 and 3.0MPa treatments was higher than 1000mg/L at the first 2025 days, which resulting in the inhibition of the activity of methane-gens, but steam explosion at 1.5MPa could operate well.