The Organic Rankine Cycle: A Promising Technology for Electricity Generation and Thermal Pollution Mitigation

Abstract

Waste heat emissions derived from cooling systems of the thermal power plant often discharged in rivers, lakes and seas, have been the direct cause of environmental problems to marine life. The problem can be solved with an organic Rankine cycle, which is considered a promising technology in electric generation and an alternative to avoid the thermal pollution of the aquatic ecosystems. The present work discusses the use of ORC system aiming to increase both thermal and overall efficiency of traditional systems already established without causing an additional thermal impact on marine species. This evaluation was based on the first and second laws of thermodynamics, applied to seven organic fluids and equations that linked the power plant overall efficiency with parameters of life quality in rivers. Results has showed that among the organic fluids chosen benzene produced the highest thermal efficiency for the ORC. Besides, an application of the proposed modelling in a thermal power plant localized near to Tubarao river, SC – Brazil is presented. Results demonstrated that it is possible to increase the overall efficiency of thermal power plant up to 11.96% using R113 as working fluid without causing thermal impact in the aquatic ecosystem.