Siliceous Scaling Aspects of Geothermal Power Generation Using Binary Cycle Heat Recovery

Abstract

Siliceous scaling potential of geothermal brines has long been an obstacle to the efficient energy recovery from some geothermal resources. In classical flash geosteam plants, the brine for disposal is separated at a temperature high enough to avoid ìsilica oversaturationî which might lead to scaling on further cooling if additional power is generated by heat recovery. Recent binary cycle heat recovery experience involved cases of brine cooling leading to ìsilica oversaturationî which did not cause extensive fouling in the plant heat exchanger. This paper presents some case histories of these successful applications. Although kinetics of siliceous precipitation was overlooked in the past, it is now approached through various design and/or operational approaches in order to minimize fouling.