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22 pages, 1980 KiB

Open AccessReview

Methods of Capture and Transformation of Carbon Dioxide (CO₂) with Macrocycles

by Edilma Sanabria, Mauricio Maldonado, Carlos Matiz, Ana C. F. Ribeiro and Miguel A. Esteso

Processes 2025, 13(1), 117; https://doi.org/10.3390/pr13010117 - 4 Jan 2025

Cited by 2 | Viewed by 2054

Rapid industrialization and the indiscriminate use of fossil fuels have generated an impact that is affecting the climate worldwide. Among the substances that are causing climate change are several gases such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) and sulphur hexafluoride (SF₆), among others. Particularly, carbon dioxide is one of the substances that has attracted the most attention from researchers, as it is responsible for more than three quarters of greenhouse gases. Because of this, many efforts have been directed towards the capture of CO₂, its separation, adsorption and transformation into products that are less harmful to the environment or that even have added value in the industry. For this purpose, the use of different types of macrocycles has been explored mainly in the last 5 years. This review seeks to present the advances that have occurred in recent years in the capture and transformation of CO₂ by different methods, to finally focus on the capture and transformation through macrocycle systems such as azacompounds, heterometallic macrocycles, calixpyrrols, modified cyclodextrins and metallic porphyrins, among others. Full article

(This article belongs to the Section Environmental and Green Processes)

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15 pages, 2200 KiB

Open AccessArticle

The Relationship between Environmental Quality, Sustainable Health, and the Coronavirus Pandemic in European Countries

by Moslem Ansarinasab and Sayed Saghaian

Sustainability 2023, 15(15), 11683; https://doi.org/10.3390/su151511683 - 28 Jul 2023

Viewed by 1838

Abstract

The emission of air pollutants weakens the body’s immune system and can increase the prevalence of coronaviruses. This study examined the effects of six environmental pollutant gases, including Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), Hydrofluorocarbons (HFC), Perfluorocarbons (PFC), and Sulphur Hexafluoride (SF6), on the prevalence of coronaviruses (i.e., coronavirus cases, total deaths, and active cases) in 30 European countries. Due to the benefits of ridge regression, this method was used to investigate the effects of those environmental pollutants on coronavirus cases. The results showed that all six gases had a positive effect on active coronavirus cases in European countries. This study concludes that industrialized European countries could focus on reducing environmental pollutants to decrease the effects of future pandemics. Full article

(This article belongs to the Special Issue Public Health and Sustainable Development: Justice, Inclusivity, and Financing for a Resilient Future)

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16 pages, 8212 KiB

Open AccessArticle

A Comparison of Partial Discharge Sensors for Natural Gas Insulated High Voltage Equipment

by Phillip Widger, Daniel Carr, Meirion Hills and Alistair Reid

Sensors 2020, 20(16), 4443; https://doi.org/10.3390/s20164443 - 9 Aug 2020

Cited by 2 | Viewed by 4147

Abstract

The research in this paper consists of practical experimentation on a gas insulated section of high voltage equipment filled with carbon dioxide and technical air as a direct replacement to sulphur hexafluoride (SF₆) and analyses the results of PD measurement by way of internal UHF sensors and external HFCTs. The results contribute to ongoing efforts to replace the global warming gas SF₆ with an alternative such as pure carbon dioxide or technical air and are applicable to mixtures of electronegative gases that have a high content of buffer gas including carbon dioxide. The experiments undertaken involved filling a full-scale gas insulated line demonstrator with different pressures of CO₂ or technical air and applying voltages up to 242 kV in both clean conditions and particle contaminated conditions. The results show that carbon dioxide and technical air can insulate a gas section normally insulated with SF₆ at phase-to-earth voltage of 242 kV and that both HFCT and UHF sensors can be used to detect partial discharge with natural gases. The internal UHF sensors show the most accurate PD location results but external HFCTs offer a good compromise and very similar location accuracy. Full article

(This article belongs to the Special Issue Acoustic, UHF and RF Sensor Technology for Partial Discharge Detection)

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11 pages, 3746 KiB

Open AccessArticle

Partial Discharge Measurements in a High Voltage Gas Insulated Transmission Line Insulated with CO₂

by Phillip Widger, Daniel Carr, Alistair Reid, Meirion Hills, Chris Stone and A. (Manu) Haddad

Energies 2020, 13(11), 2891; https://doi.org/10.3390/en13112891 - 5 Jun 2020

Cited by 3 | Viewed by 3522

Abstract

This paper uses practical experimentation to analyse the effect of replacing SF₆ with pure CO₂ in conventional gas insulated transmission line sections by studying partial discharge measurements taken with applied voltages up to 242 kV (rms). The results can also help in understanding the properties of new alternative gas mixtures which can be utilised with a ratio of up to and over 95% CO₂. The experiments undertaken involved filling a gas insulated line demonstrator with 3 bars of CO₂ and applying voltages up to 242 kV in both clean conditions and particle-contaminated enclosure conditions. The results demonstrate that CO₂ can be used to insulate gas equipment without breakdown at high voltage, however, a higher gas-filling pressure may be needed to reduce the partial discharge found in the tests presented in this paper. Another aspect of the work showed that partial discharge (PD) measurements from internal ultra-high frequency (UHF) sensors compared with a direct measurement from a capacitive divider both clearly showed the effect of contaminating particles in CO₂. However, the PD divider measurements also showed considerable external PD on the outside of the gas compartment, leading to the conclusion that UHF sensors are still regarded as having the highest sensitivity and noise immunity for gas insulated switchgear (GIS) or gas insulated transmission line (GIL) systems including when the equipment is insulated with CO₂. Full article

(This article belongs to the Special Issue Power Transmission Line Simulation)

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16 pages, 3242 KiB

Open AccessArticle

Analysis of Gaseous By-Products of CF₃I and CF₃I-CO₂ after High Voltage Arcing Using a GCMS

by Phillip Widger and Abderrahmane (Manu) Haddad

Molecules 2019, 24(8), 1599; https://doi.org/10.3390/molecules24081599 - 23 Apr 2019

Cited by 6 | Viewed by 4027

Abstract

Increasing demand for an alternative insulation medium to sulphur hexafluoride (SF₆) has led to the investigation of new environmentally friendly insulation gases which could be used in high voltage equipment on the electrical power network. One such alternative, which is currently being explored by researchers, is Trifluoroiodomethane (CF₃I) which could potentially be used in a gas mixture with carbon dioxide (CO₂) as an insulation medium. In this paper an analysis of gaseous by-products detected as a result of high voltage breakdown through pure CF₃I and a CF₃I-CO₂ gas mixture across a sphere-sphere electrode arrangement is given. Gas chromatography and mass spectrometry (GCMS) is used to identify the gaseous by-products produced as a result of high voltage arcing which causes the gas between the electrodes to dissociate. Analysing these gas by-products helps to identify the long-term behaviour of the gas mixture in high voltage equipment. Full article

(This article belongs to the Section Analytical Chemistry)

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