Enhancement in hydrogen production by thermophilic anaerobic co-digestion of organic fraction of municipal solid waste and sewage sludge – Optimization of treatment conditions

This study evaluated the technical feasibility of the anaerobic co-digestion process in the context of typical North American solid waste. Using biological activity tests, an optimal mixture was identified with 25% organic fraction of municipal solid waste (OFMSW) and 75% sewage sludge (65% raw primary sludge (RAW), 35% thickened WAS (TWAS)) based on biogas production. Also, based on the rate of biogas production, the most anaerobically biodegradable components of the OFMSW were paper and grass. The TWAS and the newspaper were found to be the least biodegradable components. Lab-scale testing indicated that alkaline pretreatment increased the biodegradability of the sewage sludge/OFMSW mixture the most, as compared to the untreated control. Thermochemically pretreated feedstocks inhibited anaerobic biodegradability as compared to the control, whereas the anaerobic biodegradability of thermally pretreated feed was not found to be significantly different from that of the control. Empirical models were developed based on alkaline dose, feed total solids concentration and particle size for biogas production and removal of TS and VS. All three experimental factors were found to be significant with respect to the response variables studied.

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Influence of the pH control strategy and reactor volume on batch fermentative hydrogen production from the organic fraction of municipal solid waste

Waste Management & Research ◽

10.1177/0734242x19826371 ◽

2019 ◽

Vol 37 (5) ◽

pp. 478-485 ◽

Cited By ~ 7

Author(s):

Francesco Baldi ◽

Renato Iannelli ◽

Isabella Pecorini ◽

Alessandra Polettini ◽

Raffaella Pomi ◽

...

Keyword(s):

Hydrogen Production ◽

Municipal Solid Waste ◽

Solid Waste ◽

Control Strategy ◽

Ph Control ◽

Organic Fraction ◽

Experimental Conditions ◽

Reactor Volume ◽

Fermentative Hydrogen Production ◽

Fermentative Hydrogen

Three different experimental sets of runs involving batch fermentation assays were performed to evaluate the influence of the experimental conditions on biological hydrogen production from the source-separated organic fraction of municipal solid waste collected through a door-to-door system. The fermentation process was operated with and without automatic pH control, at a pH of 5.5 and 6.5, food-to-microorganism ratios of 1/3 and 1/1 (wet weight basis) and with different working volumes (0.5 and 3 L). The experimental results showed that the pH control strategy and the reactor volume did not affect the final hydrogen production yield but played an important role in determining the time evolution of the process. Indeed, although the different experimental conditions tested yielded comparable hydrogen productions (with maximum average values ranging from 68.5 to 88.5 NLH2 (kgTVSOF)−1), the automatic pH control strategy improved the process from the kinetic viewpoint resulting in a t95 reduction from an average of 34.9 h without automatic pH control to an average of 19.5 h.

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