2.4 总产气量与单位产气量
厌氧消化前后TS的去除率及单位TS的产气量
见表2。在总产气量、TS去除率、单位TS产气率和消化单位TS产气量,油菜和油麦菜在60和80 g/L
的有机负荷率下都较对照有明显的提高,其中以油菜产气量的提高最为显著,总产气量都较对照提高
了9倍左右,TS减少量由9.4%提高到了57.8%和65.8%。油麦菜的产气状况不如油菜的好,可能与其成分有关,但是其单位TS产气率仍然达到了104.7和138.9mL/g,远远优于对照实验。
3 结论
(1)经过两步批次处理,油菜和油麦菜的产气性能与对照比较都得到极大提高,油菜在60和80 g/L的有机负荷率下日平均产气量分别为360mL/d和352mL/d,即0.24L/ (d·L)和0.23 L/ (d·L);油麦菜分别为314mL/d和417mL/d,即0.21 L/ (d·L) 和0.28 L/ (d·L)。
(2)油菜产气量的提高最为显著,消化时间由常规批式厌氧消化的10d左右延长到了58d,在60和80 g/L的有机负荷率下的总产气量分别达到了20.86L和20.42L,约为对照的9倍;单位TS产气量也由23.1 mL/g上升至231.7和226.8 mL/g;最高甲烷体积分数达70.7%和83.9%。
参考文献
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Two-step batch anaerobic biogasification of vegetable wastes
ZHENG MingXia LI XiuJin* LI LaiQing LIU YanPing
( College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China)
Abstract:Two-step batch technology was used to anaerobically digest cole and lettuce wastes to produce biogas. Two loading rates of 60 and 80 g/L and mesophilic temperatures of 35℃ were used. The wastes were first acidified and the liquid then separated for biogasification. The results showed that average daily biogas yield of the cole and the lettuce wastes at loading rates of 60 and 80 g/L were 360mL/d, 352mL/d, 314mL/d, and 417mL/d, respectively. The cumulative biogas production of the cole wastes was higher than that of the lettuce wastes. As compared to the single-step processes (control), two-step batch anaerobic digestion processes lasted longer times and the cumulative biogas production of the cole wastes was 20.86L and 20.42L, 9 times higher than the control; biogas yield per gram total solid (TS) loaded also increased from23.1 mL/g to 231.7 and 226.8 mL/g; the highest methane content was increased to 70.68% and 83.91%.
Key Words::Vegetable waste; two-step batch anaerobic digestion; biogas