National Research Council Canada, 6100 Royalmount, Montreal, QC, Canada.
Bioprocess Biosyst Eng. 2012 Mar;35(3):341-9. doi: 10.1007/s00449-011-0572-5. Epub 2011 Jul 22.
The owners of farm-scale anaerobic digesters are relying on off-farm wastes or energy crops as a co-digestion feedstock with animal manure in order to increase their production of methane and thus revenues. Switchgrass represents an interesting feedstock for Canadian digesters owners as it is a high-yielding low-maintenance perennial crop, well adapted to northern climate. Methane potential assays in batch tests showed methane production of 19.4 ± 3.6, 28.3 ± 1.7, 37.3 ± 7.1 and 45.7 ± 0.8 L kg(-1), for raw manure, blended manure, manure and mulched switchgrass, manure and pretreated switchgrass, respectively. Two 6-L lab-scale anaerobic digesters were operated for 130 days in order to assess the benefit of co-digesting switchgrass with bovine manure (digester #2), at a 20% wet mass fraction, compared with a manure-only operation (digester #1) The digesters were operated at an hydraulic retention time of 37 ± 6 days and at loads of 2.4 ± 0.6 and 2.6 ± 0.6 kg total volatile solids (TVS) L(-1) day(-1) for digesters #1 (D1) and #2 (D2), respectively. The TVS degradation reached 25 and 39%, which resulted in a methane production of 1.18 ± 0.18 and 2.19 ± 0.31 L day(-1) for D1 and D2, respectively. The addition of 20% on a wet mass ratio of switchgrass to a manure digester increased its methane production by 86%. The co-digestion of switchgrass in a 500 m(3) manure digester could yield up to 10.2 GJ day(-1) of purified methane or 1.1 MWh day(-1) of electricity.
农场规模的厌氧消化器所有者依赖场外废物或能源作物作为与动物粪便共消化的饲料原料，以增加其甲烷产量，从而增加收入。柳枝稷代表了加拿大消化器所有者一种有趣的饲料原料，因为它是一种高产、低维护的多年生作物，非常适应北方气候。批式试验中的甲烷潜力试验表明， raw manure、blended manure、manure and mulched switchgrass、manure and pretreated switchgrass 的甲烷产量分别为 19.4±3.6、28.3±1.7、37.3±7.1 和 45.7±0.8 L kg(-1)。为了评估与牛粪共消化柳枝稷的好处，在 130 天的时间里，使用两个 6-L 实验室规模的厌氧消化器进行了试验。与单独使用牛粪（消化器 #1）相比，在 20%湿质量分数下，与牛粪共消化柳枝稷（消化器 #2），水力停留时间为 37±6 天，负荷分别为 2.4±0.6 和 2.6±0.6 kg 总挥发性固体（TVS）L(-1)day(-1)。对于消化器 #1（D1）和 #2（D2），TVS 降解率分别达到 25%和 39%，导致甲烷产量分别为 1.18±0.18 和 2.19±0.31 L day(-1)。在牛粪消化器中，按湿质量比添加 20%的柳枝稷，可使甲烷产量增加 86%。在 500 m(3)的牛粪消化器中，共消化柳枝稷可产生高达 10.2 GJ day(-1)的净化甲烷或 1.1 MWh day(-1)的电力。
