site.btaProject Mulled to Produce Cheap Power Using High-calorific Gas from Waste Water

The water supply and sewerage utility in Stara Zagora and a local company called Elfie Tech plan to develop an installation which will generate high-calorific gas from decomposition pyrolysis of sludge from the waste water treatment plant which can be used for the production of cheap electricity, BTA learned from the manager of the company, Zheko Ganev. 

Ganev said that one tonne of lignite coals contains an average of 370 kg of hydrogen while one tonne of sludge from waste water treatment contains 400 kg. A patented pyrolitic installation will transform the hydrogen into high-calorific gas which contains 90% methane. This is close to natural gas. Unlike coal, the sludge is sulphur-free which eliminates one step in the treatment process. 

If the project is implemented, each tonne of the nearly 90 t of active sludge produced by the waste water treatment plant daily will produce about 600-620 cu m of high-calorific gas with heat of combustion of 32,000 J/kg. Used as an input in a gas turbine, the gas can generate large quantities of power at a much lower price than power derived from coal, Ganev said.