Comparison of single-stage and two-stage anaerobic co-digestion of food waste and activated sludge for hydrogen and methane production

RENEWABLE ENERGY

卷:143

Article

Baldi, F.¹  Pecorini, I.²  Lannelli, R.² 

[1] Univ Florence, Dept Ind Engn, DIEF, Via Santa Marta 3, I-50139 Florence, Italy

[2] Univ Pisa, Dept Energy Syst Terr & Construct Engn, DESTEC, Via CF Gabba 22, I-56122 Pisa, Italy

关键词: Hydrogen;    Methane;    Food waste;    Activated sludge;    Co-digestion;    Two-stage process;   

DOI  :  10.1016/j.renene.2019.05.122

来源: Elsevier

【 摘 要 】

In this study, the co-digestion of food waste and activated sludge was evaluated in a two-stage anaerobic system and compared to the traditional single-stage process. The two-stage system was composed by two reactors connected in series able to perform the fermentative and the methanogenic phases separated. Experiments were carried out in semi-continuous mode under mesophilic conditions (37 degrees C). The two-stage technology achieved an overall improvement of the anaerobic performances. Results highlighted an increase in biogas production and volatile solids degradation of 26% and 9%, respectively. Considering the whole two-stage system, i.e. the sum of the biogas productions of the first and the second digester, these percentages increased up to 35.0%. Concerning gas quality, the two-stage system achieved a hydrogen rich biogas in the first fermentative reactor and an improvement of methane content in the second methanogenic digester. The average methane content shifted from 61.2% to 70.1%. The highest methane production of the two-stage process was due to improved substrate hydrolysis, with increased amounts of volatile fatty acids made readily available in the second stage. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

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