Flue gas condensation – one option to maximise cycle efficiency of renewable and fossil fuel fired power plants

Panel: 4. Technology, products and systems

Authors:
Jürgen Peterseim, ERK Eckrohrkessel GmbH, Germany
Atul Sharma, ERK Eckrohrkessel GmbH, Germany
Dipl.Ing. Nikolai Sachno, La Mont GmbH, Germany

Abstract

Maximising the efficiency of industrial and power plants is still of interest despite the low oil and gas prices in the current scenario. Owners and operators of industries powered with fossil fuels are aware that oil and gas prices will recover in the future and that carbon costs are likely to be added in the foreseeable future. However, it needs to be acknowledged that under the current price deterioration only "low hanging fruit" energy efficiency opportunities will be implemented. Owners of renewable facilities, such as biomass plants, are still interested in improving energy efficiency to maximise production without increasing fuel demand.

Flue gas condensation is a very suitable technology for both renewable and fossil fuel plants as it can be used to maximise process heat supply and power generation. The technology is based on the condensation of water vapour in the boiler flue gas by going below the dew point. The recoverable latent heat can be used to preheat process heat flows or boiler feedwater. When improving for electricity generation a 3% cycle efficiency increase is achievable. The technology is widely used in domestic heating systems but has not reached commercial implementation in industrial and utility plants. The reasons for that are manyfold and include the additional plant complexity and the conservatism of plant owners. However, some demonstration plants are operating successfully.

In our presentation we would show the efficiency potential of flue gas condensation in power plants by analysing two case studies, one process heat and one electricity optimisation. The case studies will be based on actual plants designed by Eckrohrkessel and will include technical results, such as efficiency increase, economic results, such as investment and fuel savings and environmental results, such as emission savings.