Environmental Impact of Gas District Cooling: A Case Study of a Small Cogeneration Plant

Cogeneration is a better efficiency power generation technology compared to other
traditional fossil fuel power plant. It uses heat engine or a power station to
simultaneously generate both electricity and useful heat. Cogeneration consists of
many types of technology and one of them is Gas District Cooling (GDC). In
Malaysia, cogeneration technology has yet to catch up with only 5 GDC built but so
far environmental impact of GDC has yet to be assessed. The objective of this project
is to fill in that vacuum by assessing the environmental impact cause by GDC. The
scope of this project will be observing and analysing the amount of C02, CO, NOx
and SOx released by GDC and determine if it exceeds emission limit. Apart from the
impact on surrounding temperature is also monitored to see if there is any rise in
temperature due to the release of hot exhaust gas. The project mainly ipvolves gas
samples being collected within GDC and analysed to see the composition of the gas.
Then the temperature at the various distance from GDC are taken. The content of
NOx and SOx in the exhaust gas is compared to European Union and United States
emission standards and GDC if found to release both emission gases well below the
limit. The data is also used to compare with readings from oil-fired and coal-fired
power plants to show the reduction of NOx and SOx emission and it is found to
release far less SOx than both types of power plants. The emissions of GDC working
on full load and partial load are also compared where full load released more SOx
and NOx however partial load is less efficient and released higher temperature
exhaust gas since its heat energy is not extracted. For the surrounding the
temperature, a graph of temperature and humidity in relation with distance from
GDC is plotted and it is found to have minimal impact. All the results indicate that
GDC is a clean and safe method to produce electricity.