汽爆预处理对废弃烤后烟叶产甲烷潜力的影响

为资源化利用涉烟有机废弃物,以废弃烤后烟叶为底物进行了中温厌氧发酵实验,通过对比研究蒸汽爆破预处理及5种汽爆条件对烤后烟叶产甲烷潜力的影响,探讨汽爆在烤后烟叶厌氧发酵中应用的可行性。结果表明:未处理烤后烟叶L0的生化产甲烷潜力值高于绝大多数木质纤维素类废弃物,达到了252.7 mL·g~(-1)VS,且产气周期短,是优良的发酵原料;烤后烟叶在汽爆过程中发生固液组分分离,液体糖难以完全回收进而影响产气。与L0相比,汽爆后烟叶的生化产甲烷潜力均有下降,L1～L5分别降低了11.6%、23.0%、24.0%、22.4%及26.3%。对于烤后烟叶,尽管汽爆预处理能打开物料结构,但也会导致液体糖分大量流失,甲烷产量下降。综合考虑产品价值和处理能耗等因素,在实际应用中直接将烤后烟叶进行厌氧发酵是更优的选择。

Assessment of biomethane production from cured tobacco leaves using steam explosion pretreatment

For utilizing organic waste of tobacco, discarded and cured tobacco leaves were subjected to medium-temperature anaerobic fermentation with steam explosion pretreatment. By comparing the biochemical methane potential(BMP)of cured tobacco in five different steam explosion gradients, the feasibility of steam explosion in cured tobacco anaerobic applications is discussed. The results show that the BMP value of untreated cured tobacco leaves(L0)is the highest, reaching 252.7 mL·g^-1 VS, which is higher than most lignocellulosic wastes. Moreover, the methane production cycle is short, which means that it is a suitable material for fermentation. In the process of steam explosion, solid and liquid components of tobacco are separated and liquid sugar precipitation is hard to recover completely, resulting in the loss of part of the sugar that can be used to produce methane. Consequently, it is not favorable for methane production. Compared with that of untreated tobacco leaves(L0), the BMP of all tobacco samples after the steam explosion decreased; L1~L5 decreased by 11.6%, 23.0%,24.0%, 22.4%, and 26.3%, respectively. Although steam explosion pretreatment can open the material structure, it leads to a large loss of liquid sugar and decrease in methane production. Considering the value of the product and energy consumption of the pretreatment, it is better to directly use cured tobacco for anaerobic fermentation without steam explosion treatments, in practical applications.