| Title | Tuaropaki Miraka Clean Steam Supply Plant |
|---|---|
| Authors | Nigel Taylor |
| Year | 2011 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Tuaropaki, clean steam |
| Abstract | This paper covers the Tuaropaki Miraka Clean Steam Supply Plant which demonstrates an example of a new use for existing geothermal resources. The Tuaropaki Trust and its associated braches the Tuaropaki Power Company, Tuaropaki Farms and Tuaropaki Greenhouses are known for their innovative use of their geothermal resources in both power production and greenhouse heating. In 2010 MB Century were selected to provide a design build solution for a clean steam generation plant using existing high enthalpy geothermal resources to provide both heat and water for the generation of clean steam to be supplied to Miraka Ltd. This clean steam is being used in the production of milk powder. The generation of clean steam by converting geothermal condensate into boiler quality feedwater and reboiling that water using geothermal steam on the primary side of the exchanger is not new and has been successfully used in the pulp and paper industry in New Zealand for a number of years. The new challenges that arose from the specification for this plant included a high degree of reliability during the diary season and a high degree of purity for the clean steam with the chemistry requirements laid out in the contract. The process design for the plant is discussed, where existing plant design was greatly simplified to provide a cost effective and reliable solution. The number of vessels was reduced from fourteen to eleven. The clean steam generation side of the plant was treated as a conventional boiler plant with a single hotwell elevated above the feed water pumps that feed directly to the preheater and heat exchanger banks. The non pressurised condensed geothermal steam stripping process is considered, with a comparison to previous pressurised designs. |