Table 1 Operating data of the investigated waste utilizing biogas plants
From: Foam formation in full-scale biogas plants processing biogenic waste
Biogas plant | Substrate | Organic loading rate | Mode of operation | Installed electric capacity | Retention time | Number of digesters | Agitation |
|---|---|---|---|---|---|---|---|
BP A | 50 thousand t/a swine and cattle manure, 30 thousand t/a biogenic industrial wastes from trade and industries | 2 to 2.5 kg VS/(m3 × day) | Mesophilic, two-stage (with an upstream hydrolysis stage) | 2× 469 kWel, (7.4 mil. kWhel/a) | 25 days | Two hydrolysis digesters (520 m3 each) 2× digesters (2,300 m3 each) | Continuous stirring with two paddles |
BP B | 8.320 t/a commercial food waste, 3.070 t/a vegetable materials, 3.040 t/a grease separator contents and flotation tailings, 1.400 t/a pastry wastes, 170 t/a miscellaneous (dairy wastewater, potato wastes, old bread grain sieving wastes) | 2.8 kg VS/(m3 × day) | Mesophilic, one-stage | 860 kWel | 29 days | Two digesters (1,000 m3 each) | Recirculation and pneumatic |
BP C | Sewage sludge, approximately 480 to 640 t grease separator contents in December 2009 to March 2010 | 2.5 to 3 kg VS/(m3 × day) | Mesophilic, one-stage | No information | 20 days | Four digesters (8,000 m3 each) | Recirculation |
BP D | 36.500 t/a wastes and sludge from potato processing | 2.8 kg VS/(m3 × day) | Thermophilic, one-stage | 400 kWel; the biogas is burned and heat is used for the preparation of potato products | 36 days | One digester (3,600 m3) | Recirculation |
BP E | 22.800Â t/a grain waste products, 1.200Â t/a grease separator contents | No information | Mesophilic, two-stage (with open mash and hydrolysis stage) | No information | 30 to 35Â days | One digester (5,000Â m3) | Hydraulic |