Table 2 Operational elements of the valorization units
From: Anaerobic digestion and integration at urban scale: feedback and comparative case study
Name | Process studied | Wastes | Collection | Storage | Pretreatment | In flow | Reactor | Condition | Biogas production | Digestate/lixivia | Biogas valorization |
|---|---|---|---|---|---|---|---|---|---|---|---|
Bedzed | Living Machine1 | Wastewater | By pipe directly from household; district area restricted | – | – | – | – | – | – | – | – |
LEAP | AD in situ | Food waste | Transport by inhabitant; collection from local deposits (bike) | Pre-feed tank with grinder | – | 2m3 reactor | – | – | Composting fertilizer | CHP unit | |
Les Grisettes (Montpellier) | AD in situ | Household waste and green waste | Collection truck; district area extended | Mechanical-biological treatment and heating | 140,000 tons/year of household waste (organic + inorganic) | Based on the Valorga® process Dry condition co-digestion | Annual production: 11800000 m3 of biogas estimated | Composting 33,000 t/year | CHP unit generate yearly 22 GWh as electricity and 12 GWh as heat. Used for local installation and dwellings | ||
Brest | Compost in situ | Green waste and a fraction of organic waste from household | Transport | – | – | – | – | – | – | – | – |
Freiburg im Breisgau | AD ex situ | Organic waste from household and local commercial establishments | Transport; urban area extended | – | Mechanical sorting and crushing: Addition of water | 39,200 tons/year | Based on the Valorga® process Thermophilic condition; Dry condition; Mono-digestion; 4000 m3 | 110–120 Nm3/t input digestion | Screw press; Fertilizer 12,600 tons/year and Composting 9500 tons/year | CHP plant; 11 600,000 kWh as electricity | |
Flintenbreite (Lübeck) | AD in situ | Wastewater and organic waste from household | Independent wastewater system and collection directly from household | Shredding storage tank and sanitation | 1217 m3/year of blackwater; 3 tons/year kitchen waste | CSTR of 72 m3 | Wet condition; mesophilic temperature; HRT: 21–24 days; co-digestion | 4700 m3 CH4/year; 22,500 m3 CH4/year estimated for maximal conditions and additional co-digestion | Screw press; fertilizer and composting | CHP valorization unit | |
Jenfelder Au (Hamburg) | “Local” AD | Black water; greasy water; kitchen waste and lawn cutting | District area extended | Silage for lawn cutting | Macerator or press for lawn cutting | 30m3/days | Semi- CSTR of 900m3 | Wet condition; mesophilic condition; HRT: 25 days; co-digestion | – | Separation; fertilizer and composting; annual production estimated 1700–3500 t of compost and 50–120 t of fertilizer | CHP unit |
Quartier Vauban (Freiburg) | AD in situ | Wastewater | From one building by pipe; district area restricted | – | – | – | – | – | – | – | CHP unit |
Allermöhe (Hamburg) | Compost in situ | Wastewater and organic waste from household and green waste | Collected directly by inhabitants; transport | – | – | – | – | – | – | 40 l/cap/year | – |
Nashik | AD ex situ | Food waste (from local hotels) and blackwater | Community toilet complex and transport truck; city area restricted | Storage in septic tank | Shredding and sanitation process | 30 tons/day | 1300 m3 | Wet condition; HRT: 35 days; co-digestion | 2500 m3 of biogas/days | 1.5–2 million tons/day as manure | CHP unit to produce 3300 kWh/day (estimation) |
Noorderhoek (Sneek) | AD in situ | Blackwater, kitchen waste, and grey water (study) | Pipe directly from household; district area restricted | – | Flocculation for grey water; used of macerator for kitchen waste. | 280–670 l/days | UASB of 2.5–7 m3 | Wet condition, mesophilic temperature, HRT: 0.8–27 days; co-digestion; mono-digestion (study) | 13.8–12.2 m3 CH4/cap/year | Struvite precipitation and nitrification/denitrification tank | CHP unit; 133–148 kWh/cap/year (heat) |
Eva-Lanxmeer (Culemborg) | AD in situ; Living Machine1 | Blackwater, food waste and green waste | Independent wastewater system; social program for collect and transport | Shredding and acidification tank | 1073 m3/year | 70 m3 | Wet condition, mesophilic condition; HRT: 20 days; co-digestion | 27,000 m3 biogas/year | Composting and fertilizer | CO2 extraction and CHP | |
Malmö | AD ex situ (Sjölunda) | Blackwater and a fraction of household and food waste | Specific collect truck and vacuum collection points; urban area extended | Storage tank (vacuum collection) | Sludge thickener | 1350 l wastewater/second, only a fraction is used for AD | 6 reactor of 16,000 m3 | Wet condition; mesophilic temperature HRT: 40 days (wastewater); co-digestion | Capacity of the gas upgrading plant: 550 Nm3/h | Dewatering and fertilizer | 80% of the biogas produced is converted into fuel |
Bo01/Fullriggaren (Malmö) | AD ex situ (Kristianstad) | Food waste (co-digestion with manure) | Vacuum system; sink shredders; urban area extended | Separated tank | Mechanical sorting; shredding; extruding; sanitation | 62,500 tons/year (5500 tons of food waste) | CSTR of 2 × 5000 m3 | Wet condition; mesophilic temperature; HRT: 22 days; co-digestion | – | Fertilizer; 63,000 tons/year of liquid bio manure | Upgrading as biofuel capacity of 200 Nm3/h; 40,000 MWh/year; heating: 65% fuel: 35% |
AD ex situ (Sjölunda) | Wastewater (+ fraction of food waste greasy waste) | Pipe directly from household; urban area extended | WWTP pretreatment; sludge thickener | 1350 l wastewater/second | 6 × 1 6000 m3 | Wet condition; mesophilic temperature; HRT: 40 days; co-digestion | – | Fertilizer | Upgrading as biofuel capacity of 550 Nm3/h | ||
Hammarby Sjöstad (Stockholm) | AD in situ (Henriksdal) | Wastewater (+ fraction of food waste greasy waste) | Pipe directly from household; urban area extended | – | Chemically precipitated | 54,000 tons/year (based on dry sludge) | CSTR; 7 reactors for a total of 39,000 m3 | Wet condition; mesophilic condition (thermophilic forthcoming); HRT: 19 days | – | Dewatering and fertilizer; 56,500 tons/ year of de-watering sludge | Upgrading as biofuel; 58,000 MWh (maximum) upgraded from Henriksdal WWTP, majorly in fuel and a small fraction is upgrading in household gas for the district |
AD ex situ (Södertörn) | Food waste | Vacuum collection points and transport trucks | Storage tank (vacuum collection); urban area extended | Mechanical thickener; sanitation process | 50,000 tons/year (extended soon to 260,000 tons/year) | 2 reactors of 4500 m3 | – | Increased to 20 million Nm3 of upgraded biogas | Centrifugation and evaporation plant; 14,000 tons of bio-fertilizer yearly | Upgrading as biofuel; 80 GWh biogas (which will increase to 200 GWh). | |