Preliminary study of binary power plant feasibility comparing ORC and Kalina for low-temperature resources in Rusizi Valley, Burundi

Abstract

Low-temperature resources are located in many areas and represent a high potential as energy resources. The most efficient and cost effective way to exploit this type of resource is based on binary cycle technology. This study addresses the preliminary feasibility assessment of a binary power plant utilizing low temperature geothermal resources in the Rusizi valley in Burundi. The focus is on the selection of a working fluid, evaluating the net power output, the performance of the working fluid, and the economic analysis and comparison of an Organic Rankine Cycle and a Kalina cycle. The potential resource temperatures are in the range from 90°C to 140°C, and the mass flow of the geothermal fluid ranges between 20 kg/s and 80 kg/s. Models of the Organic Rankine Cycle and the Kalina cycle were developed and analysed by using the EES program. The obtained results revealed the feasibility of a binary power plant under various geothermal field conditions.