Department of Engineering, Aarhus University, Tjele, Denmark.
Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
Environ Technol. 2020 Mar;41(8):997-1006. doi: 10.1080/09593330.2018.1516802. Epub 2018 Sep 7.
Wheat straw and animal wastes are important feedstock for biogas production in Europe. Yet, the high content of lignocellulosic and refractory materials causes the process to be relatively slow. Therefore, pretreatment methods have been proposed to shorten the hydrolysis phase. The present study examined the effectiveness of alkali pre-treatment (AP), ultrasonic pre-treatment (UP), and alkali-ultrasonic pre-treatment (AUP) applied on wheat straw (WS), solid fraction of cattle manure (SCM) and solid fraction of slaughterhouse waste (SSHW), by monitoring solubilisation ratio, anaerobic biodegradability and methane yield. The results indicate that the solubilisation ratio of the substrates improved regardless of the types of pre-treatment applied. Though, AP was more effective on WS and SSHW than other pre-treatments (UP and AUP), with approximately 47% and 17% extra methane, respectively. Moreover, AP of SCM caused an increased in methane production rate by 100% and minimised lag phase from 16 days to 1 day during anaerobic digestion. Based on Danish conditions, only AP of WS was economical prior to the biogas process due to high extra methane yield. A positive energy budget of 8 € t was calculated. High-energy consumption during UP and AUP in laboratory scale hindered the positive benefits of these pre-treatments.
麦草和动物废物是欧洲沼气生产的重要原料。然而，高含量的木质纤维素和难处理材料导致该过程相对较慢。因此，已经提出了预处理方法来缩短水解阶段。本研究通过监测溶解比、厌氧生物降解性和甲烷产量，考察了碱预处理（AP）、超声预处理（UP）和碱-超声预处理（AUP）在麦草（WS）、牛粪固相（SCM）和屠宰废物固相（SSHW）上的应用效果。结果表明，无论应用何种预处理方法，底物的溶解比都有所提高。然而，AP 对 WS 和 SSHW 的效果优于其他预处理方法（UP 和 AUP），分别额外产生了约 47%和 17%的甲烷。此外，AP 处理 SCM 可使甲烷产率提高 100%，并将厌氧消化过程中的迟滞期从 16 天缩短至 1 天。根据丹麦的情况，只有在沼气工艺之前进行 WS 的 AP 预处理在经济上是可行的，因为其具有较高的额外甲烷产量。计算得出的正能预算为 8 欧元/t。在实验室规模下，UP 和 AUP 的高能耗阻碍了这些预处理方法的积极效益。
