Biomass CHP Technology
Decentralised heat and power from biomass CHP
We have been researching and developing solutions for biomass heat and power (CHP) for over 10 years in partnership with our network of experienced partners. We now have a range of options available to suit the customers requirements and site constraints.
BIOMASS CHP FUEL OPTIONS
Medium scale biomass chp
Due to the large fuel volumes required for medium scale systems it is often important that the combustion system is capable of operating with fuel that is readily available and does not need extensive pre-treatment such as drying. Also the Biomass CHP RHI tariff (4.1p/kWh) is much lower than the Biogas Tariff (7.6p/kWh) so the material needs to be secured at a lower cost than that for gasification to ensure this is a commercial proposition.
Medium Biomass - Description of Operation
Product development in this area is increasing rapidly with a number of different technologies hitting the market. These devices can be split into 2 general categories, Organic Rankine Cycle and Steam.
Organic Rankine Cycle
ORC devices are low pressure closed systems operating in accordance with the steam or Rankine Cycle, usually containing an organic oil. A biomass combustion chamber transfers heat energy to the organic oil medium generally by one of three mediums, directly by the combustion flue gasses (cooled to 550degC), by thermal oil (330degC) or by hot water would (150degC). The organic oil medium vaporises and is then used to drive a turbine or screw expander which are direct coupled to a generator. The vapour is then condensed to extract useful heat. Most hot water ORC devices only produce heat at up to 55degC, which is not all that useful for typical commercial heating applications so if commercial grade heat is required then the flue gas or Thermal oil ORC devices are generally used.
All of these generally use a traditional design Biomass combustion unit so the fuel quality constraints are generally minimal with the larger units (>500kWth) usually being able to burn wet and dry fuels and often waste woods and other waste materials as required (manufacturer dependent).
Organic Rankine Cycle Costs
These devices are suitable for high duty commercial and industrial heat applications, require relatively low maintenance when compared to gasification units. Their fuel flexibility allow for sourcing of very cheap materials which significantly reduces the OPEX costs against the gasification units