Mineral recovery through geothermal desalination

Research output: Chapter in Book/Conference paperConference paper

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Abstract

A recent review of mineral content in the geothermal waters of the Taupo Volcanic Zone has estimated gold content at over 20 parts per billion and silver content at 2,000 ppb (Simmons et al., 2016). Wells at Mokai and Rotokawa are estimated to be extremely rich and could produce 680-7500 kg Au/year. Lithium production from geothermal and petroleum brines are already accepted technologies but the current production techniques are not integrated seamlessly into a geothermal energy cascade. We propose to use a variant of multi-effect-distillation (MED) technology to close this gap. We present a setup that is currently on trial for caustic soda recycling from spent liquor recovered in the Bayer process for alumina production (Rahimi et al., 2016).We propose to use the same technology to concentrate the brines for mineral harvesting.
The MED technology is better known in seawater desalination due to its low electrical energy consumption, low operation cost, high thermal efficiency and compactness. MED is a process that is suitable for use on a range of water types including brackish, seawater and industrial process water requiring a thermal energy source to drive the distillation process. We propose to use the waste heat stream of the geothermal power station to power the MED process. In such a process, the process feed is heated in the first stage by the geothermal waste heat stream, thereby vaporising the feed under reduced pressure. The vapour from the first stage is then condensed in the next successive stage and giving up its latent heat to drive the evaporation of further amounts of process feed. This process is repeated across each effect (stage) within the plant, increasing the degree of internal energy recovery. Economic operation is commonly considered to be viable in the temperature range between about 65-100°C.
Original languageEnglish
Title of host publicationProceedings of the 40th New Zealand Geothermal Workshop
Subtitle of host publicationpresented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education
Place of PublicationAuckland, N.Z.
PublisherGeothermal Institute, University of Auckland
Number of pages5
Publication statusPublished - 2019
Event40th New Zealand Geothermal Workshop - Wairakei Resort, Taupo, New Zealand
Duration: 14 Nov 201816 Nov 2018
https://www.geothermalworkshop.co.nz/workshop-history/2018-workshop/

Workshop

Workshop40th New Zealand Geothermal Workshop
CountryNew Zealand
CityTaupo
Period14/11/1816/11/18
Internet address

Fingerprint

Desalination
Distillation
Minerals
Recovery
Brines
Waste heat
Seawater
Caustic soda
Water
Geothermal energy
Latent heat
Thermal energy
Vaporization
Recycling
Evaporation
Silver
Lithium
Alumina
Energy utilization
Crude oil

Cite this

Chua, H. T., Sommer, H., & Regenauer-Lieb, K. (2019). Mineral recovery through geothermal desalination. In Proceedings of the 40th New Zealand Geothermal Workshop: presented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education Auckland, N.Z.: Geothermal Institute, University of Auckland.
Chua, Hui Tong ; Sommer, Holger ; Regenauer-Lieb, Klaus. / Mineral recovery through geothermal desalination. Proceedings of the 40th New Zealand Geothermal Workshop: presented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education. Auckland, N.Z. : Geothermal Institute, University of Auckland, 2019.
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abstract = "A recent review of mineral content in the geothermal waters of the Taupo Volcanic Zone has estimated gold content at over 20 parts per billion and silver content at 2,000 ppb (Simmons et al., 2016). Wells at Mokai and Rotokawa are estimated to be extremely rich and could produce 680-7500 kg Au/year. Lithium production from geothermal and petroleum brines are already accepted technologies but the current production techniques are not integrated seamlessly into a geothermal energy cascade. We propose to use a variant of multi-effect-distillation (MED) technology to close this gap. We present a setup that is currently on trial for caustic soda recycling from spent liquor recovered in the Bayer process for alumina production (Rahimi et al., 2016).We propose to use the same technology to concentrate the brines for mineral harvesting.The MED technology is better known in seawater desalination due to its low electrical energy consumption, low operation cost, high thermal efficiency and compactness. MED is a process that is suitable for use on a range of water types including brackish, seawater and industrial process water requiring a thermal energy source to drive the distillation process. We propose to use the waste heat stream of the geothermal power station to power the MED process. In such a process, the process feed is heated in the first stage by the geothermal waste heat stream, thereby vaporising the feed under reduced pressure. The vapour from the first stage is then condensed in the next successive stage and giving up its latent heat to drive the evaporation of further amounts of process feed. This process is repeated across each effect (stage) within the plant, increasing the degree of internal energy recovery. Economic operation is commonly considered to be viable in the temperature range between about 65-100°C.",
author = "Chua, {Hui Tong} and Holger Sommer and Klaus Regenauer-Lieb",
year = "2019",
language = "English",
booktitle = "Proceedings of the 40th New Zealand Geothermal Workshop",
publisher = "Geothermal Institute, University of Auckland",

}

Chua, HT, Sommer, H & Regenauer-Lieb, K 2019, Mineral recovery through geothermal desalination. in Proceedings of the 40th New Zealand Geothermal Workshop: presented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education. Geothermal Institute, University of Auckland, Auckland, N.Z., 40th New Zealand Geothermal Workshop, Taupo, New Zealand, 14/11/18.

Mineral recovery through geothermal desalination. / Chua, Hui Tong; Sommer, Holger; Regenauer-Lieb, Klaus.

Proceedings of the 40th New Zealand Geothermal Workshop: presented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education. Auckland, N.Z. : Geothermal Institute, University of Auckland, 2019.

Research output: Chapter in Book/Conference paperConference paper

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T1 - Mineral recovery through geothermal desalination

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N2 - A recent review of mineral content in the geothermal waters of the Taupo Volcanic Zone has estimated gold content at over 20 parts per billion and silver content at 2,000 ppb (Simmons et al., 2016). Wells at Mokai and Rotokawa are estimated to be extremely rich and could produce 680-7500 kg Au/year. Lithium production from geothermal and petroleum brines are already accepted technologies but the current production techniques are not integrated seamlessly into a geothermal energy cascade. We propose to use a variant of multi-effect-distillation (MED) technology to close this gap. We present a setup that is currently on trial for caustic soda recycling from spent liquor recovered in the Bayer process for alumina production (Rahimi et al., 2016).We propose to use the same technology to concentrate the brines for mineral harvesting.The MED technology is better known in seawater desalination due to its low electrical energy consumption, low operation cost, high thermal efficiency and compactness. MED is a process that is suitable for use on a range of water types including brackish, seawater and industrial process water requiring a thermal energy source to drive the distillation process. We propose to use the waste heat stream of the geothermal power station to power the MED process. In such a process, the process feed is heated in the first stage by the geothermal waste heat stream, thereby vaporising the feed under reduced pressure. The vapour from the first stage is then condensed in the next successive stage and giving up its latent heat to drive the evaporation of further amounts of process feed. This process is repeated across each effect (stage) within the plant, increasing the degree of internal energy recovery. Economic operation is commonly considered to be viable in the temperature range between about 65-100°C.

AB - A recent review of mineral content in the geothermal waters of the Taupo Volcanic Zone has estimated gold content at over 20 parts per billion and silver content at 2,000 ppb (Simmons et al., 2016). Wells at Mokai and Rotokawa are estimated to be extremely rich and could produce 680-7500 kg Au/year. Lithium production from geothermal and petroleum brines are already accepted technologies but the current production techniques are not integrated seamlessly into a geothermal energy cascade. We propose to use a variant of multi-effect-distillation (MED) technology to close this gap. We present a setup that is currently on trial for caustic soda recycling from spent liquor recovered in the Bayer process for alumina production (Rahimi et al., 2016).We propose to use the same technology to concentrate the brines for mineral harvesting.The MED technology is better known in seawater desalination due to its low electrical energy consumption, low operation cost, high thermal efficiency and compactness. MED is a process that is suitable for use on a range of water types including brackish, seawater and industrial process water requiring a thermal energy source to drive the distillation process. We propose to use the waste heat stream of the geothermal power station to power the MED process. In such a process, the process feed is heated in the first stage by the geothermal waste heat stream, thereby vaporising the feed under reduced pressure. The vapour from the first stage is then condensed in the next successive stage and giving up its latent heat to drive the evaporation of further amounts of process feed. This process is repeated across each effect (stage) within the plant, increasing the degree of internal energy recovery. Economic operation is commonly considered to be viable in the temperature range between about 65-100°C.

M3 - Conference paper

BT - Proceedings of the 40th New Zealand Geothermal Workshop

PB - Geothermal Institute, University of Auckland

CY - Auckland, N.Z.

ER -

Chua HT, Sommer H, Regenauer-Lieb K. Mineral recovery through geothermal desalination. In Proceedings of the 40th New Zealand Geothermal Workshop: presented by the University of Auckland Geothermal Institute in conjunction with the Centre for Continuing Education. Auckland, N.Z.: Geothermal Institute, University of Auckland. 2019