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Title: Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction

Abstract

Southern Research Institute (Southern) teamed with partners Novus Energy Technologies (Novus), Carus Corporation (Carus), and Applied Membrane Technology, Inc. (AMT) to develop an innovative Geothermal ThermoElectric Generation (G-TEG) system specially designed to both generate electricity and extract high-value lithium (Li) from low-temperature geothermal brines. The process combined five modular technologies including – silica removal, nanofiltration (NF), membrane distillation (MD), Mn-oxide sorbent for Li recovery, and TEG. This project provides a proof of concept for each of these technologies. The first step in the process is silica precipitation through metal addition and pH adjustment to prevent downstream scaling in membrane processes. Next, the geothermal brine is concentrated with the first of a two stage MD system. The first stage MD system is made of a high-temperature material to withstand geothermal brine temperatures up to 150C.° The first stage MD is integrated with a G-TEG module for simultaneous energy generation. The release of energy from the MD permeate drives heat transfer across the TE module, producing electricity. The first stage MD concentrate is then treated utilizing an NF system to remove Ca 2+ and Mg 2+. The NF concentrate will be disposed in the well by reinjection. The NF permeate undergoes concentrationmore » in a second stage of MD (polymeric material) to further concentrate Li in the NF permeate and enhance the efficiency of the downstream Li recovery process utilizing a Mn-oxide sorbent. Permeate from both the stages of the MD can be beneficially utilized as the permeates will contain less contaminants than the feed water. The concentrated geothermal brines are then contacted with the Mn-oxide sorbent. After Li from the geothermal brine is adsorbed on the sorbent, HCl is then utilized to regenerate the sorbent and recover the Li. The research and development project showed that the Si removal goal (>80%) could be achieved by increasing the pH of the brine and adding Fe 3+ under several scenarios. The NF was also successful in achieving significant Ca 2+ and Mg 2+ removal (~80%) while retaining most Li in the permeate for high strength brines. MD experiments showed that geothermal brines could be significantly concentrated with little fouling due to pre-treatment.« less

Authors:
 [1];  [1]
  1. Southern Research Inst., Birmingham, AL (United States)
Publication Date:
Research Org.:
Southern Research Inst., Birmingham, AL (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Geothermal Technologies Office (EE-4G)
OSTI Identifier:
1360976
Report Number(s):
Final Technical Report
DOE Contract Number:
EE0006746
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
15 GEOTHERMAL ENERGY; lithium; geothermal; thermoelectric; sorption; membrane distillation

Citation Formats

Renew, Jay, and Hansen, Tim. Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction. United States: N. p., 2017. Web. doi:10.2172/1360976.
Renew, Jay, & Hansen, Tim. Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction. United States. doi:10.2172/1360976.
Renew, Jay, and Hansen, Tim. Thu . "Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction". United States. doi:10.2172/1360976. https://www.osti.gov/servlets/purl/1360976.
@article{osti_1360976,
title = {Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction},
author = {Renew, Jay and Hansen, Tim},
abstractNote = {Southern Research Institute (Southern) teamed with partners Novus Energy Technologies (Novus), Carus Corporation (Carus), and Applied Membrane Technology, Inc. (AMT) to develop an innovative Geothermal ThermoElectric Generation (G-TEG) system specially designed to both generate electricity and extract high-value lithium (Li) from low-temperature geothermal brines. The process combined five modular technologies including – silica removal, nanofiltration (NF), membrane distillation (MD), Mn-oxide sorbent for Li recovery, and TEG. This project provides a proof of concept for each of these technologies. The first step in the process is silica precipitation through metal addition and pH adjustment to prevent downstream scaling in membrane processes. Next, the geothermal brine is concentrated with the first of a two stage MD system. The first stage MD system is made of a high-temperature material to withstand geothermal brine temperatures up to 150C.° The first stage MD is integrated with a G-TEG module for simultaneous energy generation. The release of energy from the MD permeate drives heat transfer across the TE module, producing electricity. The first stage MD concentrate is then treated utilizing an NF system to remove Ca2+ and Mg2+. The NF concentrate will be disposed in the well by reinjection. The NF permeate undergoes concentration in a second stage of MD (polymeric material) to further concentrate Li in the NF permeate and enhance the efficiency of the downstream Li recovery process utilizing a Mn-oxide sorbent. Permeate from both the stages of the MD can be beneficially utilized as the permeates will contain less contaminants than the feed water. The concentrated geothermal brines are then contacted with the Mn-oxide sorbent. After Li from the geothermal brine is adsorbed on the sorbent, HCl is then utilized to regenerate the sorbent and recover the Li. The research and development project showed that the Si removal goal (>80%) could be achieved by increasing the pH of the brine and adding Fe3+ under several scenarios. The NF was also successful in achieving significant Ca2+ and Mg2+ removal (~80%) while retaining most Li in the permeate for high strength brines. MD experiments showed that geothermal brines could be significantly concentrated with little fouling due to pre-treatment.},
doi = {10.2172/1360976},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}

Technical Report:

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  • The TEGs referred to in this report consist of an array of thermocouple elements heated on one face by a self-contained burner and cooled on the other face by air or a liquid-to-air system. The thermocouple elements are typically semiconductor material, and they develop a voltage proportional to the temperature differential maintained across them and an available current that is proportional to the heat flow. Fuel cells consist of a two-stage system in which fuel is first processed into hydrogen and then fed, together with air, to a cell stack. In the cell stack, hydrogen releases electrons in reaction withmore » the oxygen (from the air) thus creating water and a flow of electrons. The cell stack collects the electrons liberated in the reaction and delivers the electrical energy to the external circuit or load.« less
  • An analysis of the likely conformance of current thermoelectric generators to the Army SLEEP ROC is provided. A feasibility analysis of the thermoelectric generator as a means of providing electricity, heating and cooling to a typical mobile teletype terminal is given. Findings relative to the thermoelectric generator as a candidate for the SLEEP ROC and as a primary energy source for a teletype terminal are given.
  • A conventional Ingram-type mass spectrometer was adapted to permit the study of the polarity of high-temperature species by electric deflection methods. The molecule Li/sub 2/O was found to be nonpolar and therefore to have an equilibrium angle close to 180 deg , as shown by the absence of deflection of a molecular beam by an inhomogeneous electric field. The species LiO, which was found by Berkowitz, Chupka, Blue, and Margrave, was confirmed to form a small percentage of the vapor in equilibrium with solid Li/sub 2/O. (auth)
  • Securing additional water sources remains a primary concern for arid regions in both the developed and developing world. Climate change is causing fluctuations in the frequency and duration of precipitation, which can be can be seen as prolonged droughts in some arid areas. Droughts decrease the reliability of surface water supplies, which forces communities to find alternate primary water sources. In many cases, ground water can supplement the use of surface supplies during periods of drought, reducing the need for above-ground storage without sacrificing reliability objectives. Unfortunately, accessible ground waters are often brackish, requiring desalination prior to use, and underdevelopedmore » infrastructure and inconsistent electrical grid access can create obstacles to groundwater desalination in developing regions. The objectives of the proposed project are to (i) mathematically simulate the operation of hollow fiber membrane distillation systems and (ii) optimize system design for off-grid treatment of brackish water. It is anticipated that methods developed here can be used to supply potable water at many off-grid locations in semi-arid regions including parts of the Navajo Reservation. This research is a collaborative project between Sandia and the University of Arizona.« less