Anaerobic digestion of grape pomace: Biochemical characterization of the fractions and methane production in batch and continuous digesters

• Published in: Waste management (Elmsford) 2016-04, Vol.50, p.275-282
• Main Authors: El Achkar, Jean H., Lendormi, Thomas, Hobaika, Zeina, Salameh, Dominique, Louka, Nicolas, Maroun, Richard G., Lanoisellé, Jean-Louis
• Format: Article
• Language: English
• Subjects: Anaerobic digestion; Anaerobiosis; Batch to continuous reactor; Biochemistry; Biodegradability; Biofuels - analysis; Biogas; Bioreactors; By-product valorization; Chemical Sciences; Food-Processing Industry; Grape pomace; Grapes; Industrial Waste - analysis; Material chemistry; Methane; Methane - analysis; Pilot plants; Refuse Disposal; Seeds; Vitaceae; Vitis - chemistry; Waste management; Waste Management - methods
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2016.02.028

[Display omitted] •Methane potential of grape pomace, pulp and seeds was assessed in batch mode.•Grinding increases the anaerobic biodegradability by a maximum of 22.2% for seeds.•Scale-up to pilot test succeeded, with an efficiency of 81%.•A correlation exists between biochemical fractions and methane production. In this study, we have estimated the biogas and methane production from grape pomace (variety Cabernet Franc). The physical and chemical characteristics of the raw material were determined, and the structural polysaccharides were identified and analyzed by the Van Soest method. Batch anaerobic digestions were carried out to assess the methane production of the grape pomace, pulp and seeds. The obtained cumulative methane productions are 0.125, 0.165 and 0.052Nm3kgCOD−1 for grape pomace, pulps and seeds, respectively. The effect of grinding on the methane potential of the substrates, as a mechanical pretreatment, was evaluated. We found that it increased the anaerobic biodegradability for grape pomace, pulp and seeds by 13.1%, 4.8% and 22.2%, respectively. On the other hand, the methane potential of the grape pomace was determined in a laboratory pilot plant (12L) continuously mixed with an organic loading rate of 2.5kgCODm3d−1 and a hydraulic retention time of 30days. The corresponding biogas production was 6.43×10−3Nm3d−1, with a methane content of 62.3%. Thus, the pilot plant’s efficiency compared to that achieved in the batch process was 81.2%. Finally, a significant correlation was found between the biochemical content and methane production.