Type of CHP system: Extraction from landfill

Plant owner: Afvalsturing Friesland

Commissioned: 2001

Status of plant: Commercial

Contractor details:

Van de Wiel Stortgas for gas extraction

Waukesha gas engines from ABB

Caterpillar gas engines from Geveke

Power generation: Gas engine

The gas is collected with the biogas and used in the engines for CHP production

Main fuel: Landfill gas

Nominal capacities & efficiencies:

Thermal input, biomass & waste: 6,5 MW

Total thermal input, incl. fossil fuels: 6,5 MW

Gross electrical output: 3,6 MWe

Net electrical output: 2,4 MWe

Heat output: 4,4 MJ/s

Electrical efficiency, gross: 36 %

Electrical efficiency, net: 36 %

Overall efficiency, gross: 86 %

Capacity figures are total of this landfill location + one digestion plant.

Both plants are the same order of magnitude regarding energy production.

Input biomass is calculated as biogas flow (1200 m3/hr) times heating value (19 MJ/m3)

How is plant controlled: By the amount of landfill gas

Heat backup: Natural gas for hot water

Heat usage: Heating only

Energy usage: Heating of buildings, influent of waste water treatment plant and feedstock of the anaerobic digestion plant.

Capacity of the heating network is 2.2 MW, with

1.1 MW for the digestor,

350 kW for the waste water treatment plant and

750 kW for the buildings

District heat coverage (% of total demand in DH network):100 %

DH inlet temperature: 110 °C

DH return temperature: 90°C

Waste water: No waste water is generated

Plant description:

From the landfill location of 20 hectares of MSW and industrial waste, about 1200 m3/h/ gas is extracted. This landfill gas is desulphurised and dried before combusted in the engines

Emission regulation is the NER

Annual gas production:

10 million m3 Nm3

Gas quality:

Typical composition of the landfill:

57.7% Methane,

37.4% Carbondioxide,

4.7% Nitrogen,

0.2% Oxygen,

Silicium compounds about 1 ppm,

Sulphur compounds about 900 ppm,

Halogen compounds about 6 ppm

Lower heating value about 18,5 MJ/Nm3

Engine:

Two 1.1 MW Caterpillars (36% electric efficiency + 50% heat efficiency) and

Four Waukesha engines from 300 to 475 kW (33% electric efficiency + 36% heat efficiency)

Caterpillars have flue gas heat recovery system

The gasproduction declines by about 10% per year

Staff: Usually 2 hours per day

Electricity sale info: Peak/low load periods

Total capital cost: € 2,500,000

Data collected and quality assured by: Biomass Technology Group BV.

Contact person: Harrie Knoef