NZ firm working on first commercial geothermal silica extraction plant
5 December 2016
New Zealand based Environmetals Limited (“EVM”) is presently engineering the first commercial application of its technology to extract silica from geothermal-electricity-waste fluids. After operating successful pilot plant operations to produce colloidal silica at two geothermal fields at Wairakei NZ and Kawerau NZ, EVM is now preparing to build and install the first 5,000 tpd commercial extraction plant at Kawerau.
The plant has been expected to be completed this year. The pilot plant was not a sub-scale plant but rather a sub-module of the commercial plant, so reaching scale involves adding additional sub-modules.
EVM’s extraction and processing equipment removes silica from the waste geothermal fluids (after the generation of electricity) and creates colloids in the range of 8 – 16 nanometres with a concentration of 30 – 40% silica by weight. Three provisional patents have been filed covering all EVM developments over the last five years, creating a robust Intellectual Property platform.
Geothermal electricity generation is predicted to grow as a renewable energy resource, but the presence of dissolved silica in geothermal fluids can be a limiting and costly issue for the power plant.
EVM’s proven proprietary extraction technology can assist operators to provide them with lower capex and opex through reduced silica scaling in the plant and reinjection wells, and also provides the potential for additional electricity generation.
EVM’s business model has the geothermal electricity generators buying extraction plants and supplying the silica concentrate which Environmetals then uses to create colloidal silica. The processed colloidal silica will then be sold by EVM on the international markets, where there is considerable and increasing demand.
Source: Think Geoenergy