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Mdlovu NV, Lin KS, Tang CY, Chen WC, Hussain J. Mineralization of SF 6 and NF 3 fluorinated compounds for greenhouse gas abatement by oxalates. CHEMOSPHERE 2024; 358:142186. [PMID: 38701860 DOI: 10.1016/j.chemosphere.2024.142186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 04/12/2024] [Accepted: 04/26/2024] [Indexed: 05/05/2024]
Abstract
Fluorinated compounds (FCs) such as sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3) have garnered attention due to their environmental impact. This study investigates the mineralization and removal of two potent FCs: SF6 and NF3. The results confirm that utilizing various oxalate salts leads to the formation of corresponding metallic fluorides: lithium fluoride (LiF), sodium fluoride (NaF), and potassium fluoride (KF), validating the occurrence of mineralization reactions. Among the oxalate salts, sodium oxalate demonstrates the highest mineralization efficiency in both SF6 and NF3 removal. Real-time Fourier transform infrared spectroscopy (FT-IR) gas-phase analysis confirms rapid and complete gas removal within a short reaction time using the selected oxalate salts. Meticulous mass balance calculations revealed that oxalates (LiF, NaF, and KF) yielded sulfur (S) at rates of 92.09%, 91.85%, and 84.98% following SF6 mineralization. Additionally, the conversion rates of oxalates to the corresponding metallic fluorides (LiF, NaF, and KF) after SF6 mineralization were 98.18%, 95.82%, and 95.21%, respectively. Similarly, after NF3 mineralization, these conversion rates stood at 92.18%, 90.67%, and 90.02%, respectively. The removal efficiencies for SF6 (1000 ppm) were 4.98, 12.01, and 7.23 L/g, while those for NF3 (1000 ppm) were 14.1, 12.6, and 11.7 L/g, respectively. Notably, sodium oxalate exhibits superior effectiveness, achieving 100% SF6 conversion within 30 min and 100% NF3 conversion within 50 min. This work underscores the potential of oxalate mineralization as a promising strategy for efficient and rapid removal of potent fluorinated compounds, paving the way for environmentally benign FC remediation techniques with broader implications for sustainable gas treatment technologies.
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Affiliation(s)
- Ndumiso Vukile Mdlovu
- Department of Chemical Engineering and Materials Science/Environmental Technology Research Center, Yuan Ze University, Taoyuan City, 32003, Taiwan.
| | - Kuen-Song Lin
- Department of Chemical Engineering and Materials Science/Environmental Technology Research Center, Yuan Ze University, Taoyuan City, 32003, Taiwan.
| | - Cheng-Yang Tang
- Department of Chemical Engineering and Materials Science/Environmental Technology Research Center, Yuan Ze University, Taoyuan City, 32003, Taiwan.
| | - Wei-Chung Chen
- Department of Chemical Engineering and Materials Science/Environmental Technology Research Center, Yuan Ze University, Taoyuan City, 32003, Taiwan.
| | - Jamshid Hussain
- Department of Chemical Engineering and Materials Science/Environmental Technology Research Center, Yuan Ze University, Taoyuan City, 32003, Taiwan.
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An M, Prinn RG, Western LM, Zhao X, Yao B, Hu J, Ganesan AL, Mühle J, Weiss RF, Krummel PB, O'Doherty S, Young D, Rigby M. Sustained growth of sulfur hexafluoride emissions in China inferred from atmospheric observations. Nat Commun 2024; 15:1997. [PMID: 38443346 PMCID: PMC10915133 DOI: 10.1038/s41467-024-46084-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 02/14/2024] [Indexed: 03/07/2024] Open
Abstract
Sulfur hexafluoride (SF6) is a potent greenhouse gas. Here we use long-term atmospheric observations to determine SF6 emissions from China between 2011 and 2021, which are used to evaluate the Chinese national SF6 emission inventory and to better understand the global SF6 budget. SF6 emissions in China substantially increased from 2.6 (2.3-2.7, 68% uncertainty) Gg yr-1 in 2011 to 5.1 (4.8-5.4) Gg yr-1 in 2021. The increase from China is larger than the global total emissions rise, implying that it has offset falling emissions from other countries. Emissions in the less-populated western regions of China, which have potentially not been well quantified in previous measurement-based estimates, contribute significantly to the national SF6 emissions, likely due to substantial power generation and transmission in that area. The CO2-eq emissions of SF6 in China in 2021 were 125 (117-132) million tonnes (Mt), comparable to the national total CO2 emissions of several countries such as the Netherlands or Nigeria. The increasing SF6 emissions offset some of the CO2 reductions achieved through transitioning to renewable energy in the power industry, and might hinder progress towards achieving China's goal of carbon neutrality by 2060 if no concrete control measures are implemented.
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Affiliation(s)
- Minde An
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
| | - Ronald G Prinn
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Luke M Western
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
- Global Monitoring Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, 80305, USA
| | - Xingchen Zhao
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Bo Yao
- Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences, Fudan University, Shanghai, 200438, China.
- Meteorological Observation Centre of China Meteorological Administration (MOC/CMA), Beijing, 100081, China.
| | - Jianxin Hu
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Anita L Ganesan
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - Jens Mühle
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093, USA
| | - Ray F Weiss
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, 92093, USA
| | - Paul B Krummel
- Climate, Atmosphere and Oceans Interactions, CSIRO Environment, Aspendale, VIC, 3195, Australia
| | - Simon O'Doherty
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
| | - Dickon Young
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
| | - Matthew Rigby
- Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
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Cui Z, Li Y, Xiao S, Tian S, Tang J, Hao Y, Zhang X. Recent progresses, challenges and proposals on SF 6 emission reduction approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167347. [PMID: 37774865 DOI: 10.1016/j.scitotenv.2023.167347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 09/06/2023] [Accepted: 09/23/2023] [Indexed: 10/01/2023]
Abstract
The increasing utilization and emission of sulfur hexafluoride (SF6) pose severe threats to the climate and the environment, owing to its potent greenhouse gas properties. In this paper, we comprehensively review the recent progresses of SF6 emission reduction approaches. Currently, the use and emission of SF6 are still on the rise, and mainly concentrated in the power industry. Restrictive use and emission reduction policies are fundamental step in guiding SF6 emission, but they are poor promoted in developing economies. More specific policies and regulations are needed in conjunction with timely and accurate assessments of SF6 atmospheric properties and emissions. SF6 recovery is the direct emission reduction approach, but defects in recovery methods and equipment limit its applications. The development of SF6 purification technologies and optimizations in recovery devices and processes are needed for its treatment of different regions and SF6 volumes. SF6 degradation is the final step of waste gas treatment, and its development needs to better balance the degradation rate and product selectivity, as well as to improve their multi-scenario responsiveness. SF6 substitution is a necessity for future large-scale SF6 emission reduction. Improvements in SF6-free applications and its long-term stability are critical via new gas design, gas mixture optimization and equipment updates. Finally, all the emission reduction approaches are closely related, and promoting their synergistic development and complementarity is the ultimate way to realize SF6 lifecycle management.
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Affiliation(s)
- Zhaolun Cui
- School of Electric Power Engineering, South China University of Technology, Guangzhou, People's Republic of China
| | - Yi Li
- School of Electrical Engineering and Automation, Wuhan University, Wuhan, People's Republic of China
| | - Song Xiao
- School of Electrical Engineering and Automation, Wuhan University, Wuhan, People's Republic of China
| | - Shuanngshuang Tian
- Key Laboratory for High-Efficiency Utilization of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, People's Republic of China
| | - Ju Tang
- School of Electrical Engineering and Automation, Wuhan University, Wuhan, People's Republic of China
| | - Yanpeng Hao
- School of Electric Power Engineering, South China University of Technology, Guangzhou, People's Republic of China.
| | - Xiaoxing Zhang
- Key Laboratory for High-Efficiency Utilization of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan 430068, People's Republic of China.
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Parthiban A, Gopal AAR, Siwayanan P, Chew KW. Disposal methods, health effects and emission regulations for sulfur hexafluoride and its by-products. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126107. [PMID: 34020356 DOI: 10.1016/j.jhazmat.2021.126107] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/30/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
Sulfur hexafluoride (SF6) is the most potent greenhouse gas contributed by the power and semiconductor industries. The global emissions of gas in the past 10 years have increased tremendously due to lack of disposal routes. This was brought to 190 nations' attention in the Kyoto Protocol for the need of emission control measures to reduce its impacts of climate change and global warming. Various novel techniques have surfaced to tackle this issue, such as non-thermal plasma (NTP) which includes radio frequency plasma, microwave plasma, dielectric barrier discharge, and electron beam. The main by-products resulting from the decomposition of SF6 by these techniques are sulfur oxyfluorides, sulfur dioxide, hydrofluoric acid, and fluorine gas. This environmental and health effects as well as global emission of SF6 gas are considered a threat to humans and the climate, where modern disposal methods of contaminated SF6 gas and its by-products should replace the conventional approaches. Relevant government policies on the safety and disposal concern of SF6 gas are reviewed and challenges and further research directions for the disposal of SF6 gas are highlighted in this review article.
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Affiliation(s)
- Anupreetha Parthiban
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia
| | - Avinash Ashwin Raj Gopal
- TNB Research Sdn. Bhd., Kawasan Institusi Penyelidikan, Jalan Ayer Itam, 43000 Kajang, Selangor Darul Ehsan, Malaysia
| | - Parthiban Siwayanan
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
| | - Kit Wayne Chew
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia; College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China.
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Replacing SF6 in Electrical Gas-Insulated Switchgear: Technological Alternatives and Potential Life Cycle Greenhouse Gas Savings in an EU-28 Perspective. ENERGIES 2020. [DOI: 10.3390/en13071807] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To date, atmospheric concentrations of sulfur hexafluoride (SF6) are the most potent among the greenhouse gases identified by the Intergovernmental Panel on Climate Change (IPCC) and are still rising. In the EU-28, SF6 has been banned from several applications, however, an important exception is gas-insulated electrical switchgear (GIS) for which cost-effective and environmentally sound alternatives were unavailable when the F-Gas regulation was last revised in 2014. To date, after some recent innovations, we argue that the phasing out of SF6 could spur the accelerated development of alternatives with a lower carbon footprint. In the EU-28, the SF6 amount in switchgear is unclear. In this paper, we estimated the SF6 amount to be between 10,800 and 24,700 t (with a mode at 12,700 t) in 2017, resulting in 68 to 140 t of annual emissions from operational leakage only, corresponding to 1.6 to 3.3 Mt of CO2-eq. We additionally calculated the potential greenhouse gas savings over the lifecycle of one exemplary 145 kV gas-insulated switchgear bay upon replacing SF6 by decafluoro-2-methylbutan-3-one (C5-FK) and heptafluoro-2-methylpropanenitrile (C4-FN) mixtures. Projecting these results over the EU-28, a phase-out scenario starting from 2020 onwards could reduce the carbon footprint by a median of 14 Mt of CO2-eq, over a period of 50 years. Extrapolation to medium voltage could be assumed to be of a similar magnitude.
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Abstract
This paper investigates the possible options for achieving a substantial reduction in a substation footprint using air-insulated switchgear as a more environmentally-friendly alternative to gas-insulated substations that use SF6 gas. Adopting a new approach to surge arrester location and numbers, International Electrotechnical Commission (IEC) minimum clearances can be successfully selected instead of the maximum clearances as currently adopted by many utilities, as is the case in the UK. In addition, innovative alternative compact busbar arrangements using vertical and delta configurations have been proposed by the authors. A further opportunity for compaction is offered by the application of compact and integrated technology offered from several manufacturers. The full overvoltage control within the entire substation under any surge condition is a key aspect of the feasibility of this type of substation. This work demonstrates that the new design option can be an attractive alternative for future substation configuration with minimum footprint.
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