Type of CHP system: Gasification

Plant owner: Brook Hall Estate

Commissioned: (reconstructed):1997 (2002)

Status of plant: Demonstration

Contractor details:

Brook Hall Estate constructed the gasifier, with the assistance of Rural Generation Ltd.  All of the plant is purpose designed with the exception of the IVECO diesel engine, which is a standard item.

Power generation: Choose from list

The producer gas is fed into the air intake of engine and on turbine it is pressurised

Main fuel: Wood chips

300 tonnes willow chips consumption per year, typical moisture content is 8-10% plus 10,000 liters of diesel fuel (5 liters per hour of operation, 2000 oper. hours)

Nominal capacities & efficiencies:

Thermal input, biomass & waste: 0,43 MW

Total thermal input, incl. fossil fuels: 0,5 MW

Gross electrical output: 0,12 MWe

Net electrical output: 0,096 MWe

Heat output: 0,32 MJ/s

Electrical efficiency, gross: 32 %

Electrical efficiency, net: 28 %

Overall efficiency, gross: 72 %

Gasifier produces 180 m3 per hour

Average diesel consumption is 18%

How is plant controlled: By electricity demand

Heat backup: Heat recovery from generator using two heat exchangers W/W and G/W and hot water storage tank

Heat usage: Heating only

Energy usage: All electricity is exported to the National Grid.  Heat is used on site for space heating of buildings, grain drying and wood chip drying

District heat coverage (% of total demand in DH network): 75 %

DH inlet temperature: 70°C °C

DH return temperature: 62°C°C

Heat storage size: 9m³ tank m3

Hours of full load that the heat storage can meet: 6 hours

Fuel storage: Batch fed system containing 12 m3 approx. 18hrs operation

Waste water: 1.2 liter per hour stubble ground

Ash discharge: Spread on stubble ground

Plant description:

This is a wood fuelled gasifier that runs mainly on willow chip.  The gasifier delivers gas to the air intake of a standard diesel engine.  The diesel engine typically runs on 18% diesel and 82% wood gas.  The diesel engine is connected directly to a generator.  Heat is recovered from the engine jacket and from the exhaust.  The gasifier can also connected to a gas turbine, which is also situated on site.  This has been installed as a “proof of concept” demonstrator and the gas turbine does not have a power generation facility.

Fuel feeding system: Batch

Gasifier: Pressurised down draft

Gas quality:

27% CO

3.4% CH4

11% H2


Gas cleaning: Cyclones and scrubbing tower.

Engine: IVECO 8210i 02 diesel engine

Flue gas cleaning: not applicable

Staff: Plant only operates at daytime (10 hr/day).  2hrs per day maintenance.

Electricity sale info: SATOD – Season and time of day tariff.

Total capital cost: € 210,000

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

Contact person: Harrie Knoef