| Title | Cost-Effective Silica Elimination in Geothermal Operations: The CaSil Advantage |
|---|---|
| Authors | Michael Schweig, James H. Johnston, Thomas Borrmann, H. Puri Fraser |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Silica scaling poses a significant challenge to geothermal energy production worldwide, blocking valves, heat exchangers, and reinjection wells, and effectively limiting energy output. Existing mitigation strategies are only partially effective, requiring costly and time-consuming maintenance. CaSil Technologies Ltd has developed a transformative solution that tackles silica scaling at its source. Instead of delaying silica precipitation, the CaSil process chemically captures dissolved silica and converts it into a stable calcium silicate hydrate (CaSil) material. With fast reaction kinetics, it reduces the Silica Saturation Index (SSI) well below 1, effectively eliminating silica scaling. The resulting CaSil particles are small, stable, and non-adherent, allowing them to flow freely through equipment without causing sticking to metal surfaces. The CaSil technology has been successfully demonstrated at automated pilot scale across four geothermal fields in New Zealand, each with distinct brine chemistries. In all cases, the SSI was consistently reduced to well below 1, confirming the technology’s broad applicability. Field work in Indonesia further validated its effectiveness under challenging conditions with a highly silica saturated and hyper-saline brine. In addition to its technical performance, CaSil offers a cost-competitive solution with multiple co-benefits. This paper presents a cost–benefit analysis comparing CaSil to conventional silica mitigation methods, highlighting its economic and operational advantages. |