Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions
The demand for lithium has continued to grow over the years due to its growing use in lithium batteries and electric vehicles, with a 2020 study suggesting that the annual demand for lithium is projected to reach >1,000,000 tonnes by 2030. The precious metal can be found both on land and in the o...
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| Format: | Final Year Project (FYP) |
| Language: | English |
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Nanyang Technological University
2024
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| Online Access: | https://hdl.handle.net/10356/177148 |
| _version_ | 1811679038732763136 |
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| author | Lim, Xin Yi |
| author2 | Wang Rong |
| author_facet | Wang Rong Lim, Xin Yi |
| author_sort | Lim, Xin Yi |
| collection | NTU |
| description | The demand for lithium has continued to grow over the years due to its growing use in lithium batteries and electric vehicles, with a 2020 study suggesting that the annual demand for lithium is projected to reach >1,000,000 tonnes by 2030. The precious metal can be found both on land and in the ocean. While lithium on earth has been extensively mined, the ocean is still a relatively untapped but large source of lithium. Consequently, much research has been done into potential methods of seawater lithium extraction — including conventional adsorption, adsorptive membranes, liquid-liquid extraction and electrochemical methods.
In this work, we integrated Li2TiO3, an adsorbent, into a nanofibrous membrane scaffold via electrospinning. Four types of nanofibrous membranes were synthesised: a membrane with only polyacrylonitrile (PAN); a direct-blend membrane with both PAN and the adsorbent; a direct-blend membrane with PAN, the adsorbent and pores in the nanofibers; and a core-shell membrane with PAN and pores in the nanofibers. Static adsorption capacity tests in 1 ppm and 10 ppm of both pure lithium and mixed ion (Li+, Na+ and Mg2+) solution were conducted to determine their adsorption capacity.
The performance of the porous direct-blend membrane was the highest in both 1 ppm and 10 ppm pure lithium solution. In the mixed ion solution, selectivity of Li+ over other competing ions generally decreased at lower concentrations. Overall adsorption of Li+ was highest for the adsorbent/PAN membrane, while the porous direct-blend membrane was the highest in 10 ppm. The adsorbent/PAN membrane exhibited the highest selectivity for Li over Na ions for both concentrations and the highest Li/Mg selectivity for 10 ppm. However, the porous direct-blend membrane had the highest Li/Mg selectivity at 1 ppm.
Considering both adsorption capacity and selectivity for lithium, the adsorbent/PAN membrane has shown the highest potential for lithium recovery so far. However, dynamic adsorption tests and further tweaking will be required to develop an adsorptive membrane that can be used on a large scale, as the adsorption capacities of the membranes are still low at lower concentrations of lithium. |
| first_indexed | 2024-10-01T03:02:48Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/177148 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:02:48Z |
| publishDate | 2024 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-10356/1771482024-05-24T15:34:44Z Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions Lim, Xin Yi Wang Rong School of Civil and Environmental Engineering Nanyang Environment and Water Research Institute RWang@ntu.edu.sg Engineering Electrospinning Lithium adsorption Membrane The demand for lithium has continued to grow over the years due to its growing use in lithium batteries and electric vehicles, with a 2020 study suggesting that the annual demand for lithium is projected to reach >1,000,000 tonnes by 2030. The precious metal can be found both on land and in the ocean. While lithium on earth has been extensively mined, the ocean is still a relatively untapped but large source of lithium. Consequently, much research has been done into potential methods of seawater lithium extraction — including conventional adsorption, adsorptive membranes, liquid-liquid extraction and electrochemical methods. In this work, we integrated Li2TiO3, an adsorbent, into a nanofibrous membrane scaffold via electrospinning. Four types of nanofibrous membranes were synthesised: a membrane with only polyacrylonitrile (PAN); a direct-blend membrane with both PAN and the adsorbent; a direct-blend membrane with PAN, the adsorbent and pores in the nanofibers; and a core-shell membrane with PAN and pores in the nanofibers. Static adsorption capacity tests in 1 ppm and 10 ppm of both pure lithium and mixed ion (Li+, Na+ and Mg2+) solution were conducted to determine their adsorption capacity. The performance of the porous direct-blend membrane was the highest in both 1 ppm and 10 ppm pure lithium solution. In the mixed ion solution, selectivity of Li+ over other competing ions generally decreased at lower concentrations. Overall adsorption of Li+ was highest for the adsorbent/PAN membrane, while the porous direct-blend membrane was the highest in 10 ppm. The adsorbent/PAN membrane exhibited the highest selectivity for Li over Na ions for both concentrations and the highest Li/Mg selectivity for 10 ppm. However, the porous direct-blend membrane had the highest Li/Mg selectivity at 1 ppm. Considering both adsorption capacity and selectivity for lithium, the adsorbent/PAN membrane has shown the highest potential for lithium recovery so far. However, dynamic adsorption tests and further tweaking will be required to develop an adsorptive membrane that can be used on a large scale, as the adsorption capacities of the membranes are still low at lower concentrations of lithium. Bachelor's degree 2024-05-24T04:31:14Z 2024-05-24T04:31:14Z 2024 Final Year Project (FYP) Lim, X. Y. (2024). Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/177148 https://hdl.handle.net/10356/177148 en EN-31 application/pdf Nanyang Technological University |
| spellingShingle | Engineering Electrospinning Lithium adsorption Membrane Lim, Xin Yi Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title | Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title_full | Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title_fullStr | Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title_full_unstemmed | Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title_short | Fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| title_sort | fabrication of electrospun adsorptive membranes for lithium extraction from dilute aqueous solutions |
| topic | Engineering Electrospinning Lithium adsorption Membrane |
| url | https://hdl.handle.net/10356/177148 |
| work_keys_str_mv | AT limxinyi fabricationofelectrospunadsorptivemembranesforlithiumextractionfromdiluteaqueoussolutions |