An industrial project of producing green electricity from waste heat is being trailled in UK’s Hartlepool. Huntsman Pigments, which develops titanium dioxide pigment to be used in paints at its Greatham site, has partnered with DRD Power for the project that uses 160 year old technology.
The £1m project, partially funded by the Carbon trust, can recover the vast quantities of low-grade heat – between 90-130°C – generated by process industries, which is currently emitted into the atmosphere. Hot water from the Huntsman plant will generate up to 200 kilowatts of electricity – saving between 600 and 750 tonnes of a year. It is thought that the project could save between 600 and 750 tonnes of carbon emissions per year and will be capable of generating 200kW of electricity. According to the companies this is a massive opportunity on Teesside because of its heavy industry, including steel, cement, power generation and processing sectors.
From March 2011, the plant will be trialling the system that uses the waste water to heat liquid with a lower boiling temperature, which in turn powers a generator. The advantage lies in the use of low temperature heat. The technology is based on the Organic Rankine Cycle (ORC) which has been around since the 1850’s. In the Rankine cycle an external heat source heats a working fluid (commonly water) increasing it’s temperature and pressure (steam) and, therefore, it’s potential energy. This energy is converted into rotational energy through an expander, which, in turn, drives a generator to produce electricity. An ORC unit uses an organic working fluidthat has a lower boiling point than waterto extract energy from low-grade heat sources.