To valorize the combustible, non-biodegradable fraction of sorted municipal solid waste as process heat for glasshouse operation,complementing thereby the process heat generated through biomethanation and biogas burning of the biodegradable part of that municipal solid waste.

The project concerns 26 000 tons including 85 % municipal solid waste and 15 % sewage sludge and 3 ha of glasshouses at the city of Gueret, France.
The combustible, non bio-degradable fraction of sorted municipal solid waste will be burned in a 2 325 kW boiler, equipped with a post-combustion unit, a waterjacket, a neutralizing unit and a recovery unit, as well as, upstream, a 100 m3 feedstock storage place and, downstream, a 100 m3 hot water storage tank at 85 C.
Process heat will be furnished to the glasshouses via 2500 kW high-Joule/low-Joule heat exchangers. Yearly 25 000 MWh are needed in the plant:
80 % originates from the proposed combustion, 15 % from biogas and 5 % from city gas. The complete system includes therefore 2 furnaces totalizing 8 700 kW to generate process heat from biogas and from complementary city gas. The latter are not part of the present project. Safety will be ensured by a set of air coolers totalizing 1988 kW.
32 % of the 25 000 MWh of the yearly produced process heat are needed for internal use, leaving 68 % for glasshouse operation and other uses.
Heat and temperature at various places will be continuously monitored. The colleted data will be stored and regularly treated. The economics of the system will be based on a 20 years exploitation. The present system offers a simple payback of 3.3 years when compared to a standard solution solely based on gas and not including this combustion unit.