CO2 Gas Mixture Research Articles

Black carbon emissions from turbulent buoyant non-premixed flames representative of flares in the upstream oil and gas sector

Gas flaring, the pervasive oil and gas industry process of using turbulent buoyant non-premixed flames to destroy unwanted flammable gases, is an important global source of carbonaceous soot or black carbon (BC). However, experimental data and reliable models with which to predict these emissions over a range of flare gas compositions and operating conditions relevant to upstream oil and gas production sites (which account for 90 % of global flaring) do not exist. In the absence of alternatives, most official reporting and inventory estimates are based on single-valued emission factors that are known to be insufficient and inaccurate. This work addresses this gap through parametric experiments to measure BC emissions from vertical lab-scale flares at Reynolds and Froude number conditions directly relevant to flares at upstream oil and gas production sites, burning multicomponent C1-C7 alkane, CO2, and N2 flare gas mixtures typical of flares in North Dakota, USA and Alberta, Canada. Analysis reveals that BC emission rates fall under two different regimes corresponding to the transition buoyant and transition shear regimes of turbulent buoyant non-premixed flares previously proposed by Delichatsios based on visual flame observations and distinguished by the product of Reyolds number and the square of the fire Froude number. Within the transition buoyant regime, BC emissions are simply proportional to total volumetric fuel flowrate whereas within the transition shear regime BC emission are inversely proportional to the exit strain rate. For a narrow range of methane-dominated hydrocarbon mixtures relevant to upstream oil and gas flaring, empirical models are presented for each regime that reliably predict BC emissions scaled by the mean carbon number of the fuel. Though ultimately limited to the specific conditions considered in this study, these empirical models nevertheless are a significant improvement over existing, widely used single valued emission factors.

Anaerobic digestion biogas upgrading using a two-stage membrane system under pilot-scale conditions.

In the present work, the construction, and operation of a pilot-scale biogas upgrading system is presented, employing 2 commercial polyimide (PI) membranes. The Upgrading system treats biogas produced via anaerobic digestion of the sludge, produced from the treatment of municipal wastewater in the facilities of Thessaloniki's Wastewater Treatment Plant. The goal of the separation unit is the production of high purity biomethane (>95%) for potential reuse in terms of energy. The fabrication of the pilot scale system includes the scale up of a laboratory setup separating CO2 from binary CH4–CO2 gas mixture. After the stability tests of the process, for the operation of 5 months (February to June 2023) the purity and recovery of CH4 in the final gas product. The experimental results showed an average recovery of CH4 of 95.7% for an average 55% feed composition, whereas the average purity in the final product was equal to 82.4%. The purity results were lower because of the N2 presence in the product stream (average 17.5%). After normalization with the help of the lab-scale binary results, the expected results assuming N2 absence would be 99.8% CH4 purity and 67% CH4 recovery. Finally, 3 different membrane configurations are compared in terms of their energy production, concluding to the efficiency of 2-stage configuration with recycling stream for the optimal combination of theoretical stage cut fractions.

Enhanced methanol selectivity and synthesis in a non-catalytic dielectric barrier discharge (DBD) plasma reactor

Direct utilisation of CO2 to methanol via environmentally friendly gas-to-liquid processes with plasma poses various challenges, such as low methanol selectivity. This study explores the non-catalytic hydrogenation of CO2 and CO gas mixtures in a self-cooling dielectric barrier discharge (DBD) plasma at atmospheric pressure and temperature. Small amounts of N2 and argon were input as auxiliary gases to investigate their effect on methanol production and a probable reaction mechanism was suggested. A H2 + CO2 + CO + N2 mixture minimised methanation and the reverse water–gas shift competitive reactions, thus enhancing methanol selectivity and yield to 86 % and 22.5 %, respectively. Furthermore, N2 helped reduce plasma power requirements, stabilised the discharge, and displayed suitable third-body properties able to tune up plasma reactions yielding a better methanol production rate than argon. Our findings reveal that plasma performance can be enhanced using a suitable reactant composition in combination with gas additives (in this case, N2) to improve methanol synthesis.

Stability of CO2/N2 foam generated in CaCO3 nanoparticle/CTAB aqueous dispersion

In an attempt to design a thermally stable foam with carbon sink attributes, the foamability and stability of aqueous foams generated from dispersions of CaCO3 nanoparticles (NPs) and hexadecyltrimethylammonium bromide (CTAB) are investigated. Much higher foam stability is reported here relative to literature. When compared to CTAB alone, the addition of CaCO3 NPs increases foam half-life from 5–7 min to 5–6 h in the presence of pure N2 and a gas mixture of CO2 and N2, respectively. Although there is no evidence of CTAB adsorption onto the NPs, the presence of CTAB is crucial to create the initial foam structure that is later stabilized by a network of NPs. Relative to CTAB alone, CaCO3 NPs/CTAB foam displays a higher bubble density and an average bubble size reduction of 67 %. In addition, CaCO3 NPs/CTAB foam is 20-fold more stable at 80 °C.

Selective CO2‐to‐Syngas Conversion Enabled by Bimetallic Gold/Zinc Sites in Partially Reduced Gold/Zinc Oxide Arrays

AbstractElectrocatalytic CO2‐to‐syngas (gaseous mixture of CO and H2) is a promising way to curb excessive CO2 emission and the greenhouse gas effect. Herein, we present a bimetallic AuZn@ZnO (AuZn/ZnO) catalyst with high efficiency and durability for the electrocatalytic reduction of CO2 and H2O, which enables a high Faradaic efficiency of 66.4 % for CO and 26.5 % for H2 and 3 h stability of CO2‐to‐syngas at −0.9 V vs. the reversible hydrogen electrode (RHE). The CO/H2 ratios show a wide range from 0.25 to 2.50 over a narrow potential window (−0.7 V to −1.1 V vs. RHE). In situ attenuated total reflection surface‐enhanced infrared absorption spectroscopy combined with density functional theory calculations reveals that the bimetallic synergistic effect between Au and Zn sites lowers the activation energy barrier of CO2 molecules and facilitates electronic transfer, further highlighting the potential to control CO/H2 ratios for efficient syngas production using the coexisting Au sites and Zn sites.

Selective CO2 -to-Syngas Conversion Enabled by Bimetallic Gold/Zinc Sites in Partially Reduced Gold/Zinc Oxide Arrays.

Electrocatalytic CO2 -to-syngas (gaseous mixture of CO and H2 ) is a promising way to curb excessive CO2 emission and the greenhouse gas effect. Herein, we present a bimetallic AuZn@ZnO (AuZn/ZnO) catalyst with high efficiency and durability for the electrocatalytic reduction of CO2 and H2 O, which enables a high Faradaic efficiency of 66.4 % for CO and 26.5 % for H2 and 3 h stability of CO2 -to-syngas at -0.9 V vs. the reversible hydrogen electrode (RHE). The CO/H2 ratios show a wide range from 0.25 to 2.50 over a narrow potential window (-0.7 V to -1.1 V vs. RHE). In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy combined with density functional theory calculations reveals that the bimetallic synergistic effect between Au and Zn sites lowers the activation energy barrier of CO2 molecules and facilitates electronic transfer, further highlighting the potential to control CO/H2 ratios for efficient syngas production using the coexisting Au sites and Zn sites.

Accurate description of gas hydrates of carbon dioxide and hydrogen for storage and transportation

This paper reports theoretical study of stability zones and composition of “H2 + CO2” clathrate hydrates of cubic structure I (sI) and II (sII) in dependence on pressure and temperature for different gas phase composition using extended van der Waals and Platteeuw statistical thermodynamic model. It was found that rising of CO2 content in H2 + CO2 gas mixture phase makes formation of sI hydrate more thermodynamically preferable rather than sII hydrate, and in the same time CO2 content increasing reduces formation pressure of the resulting hydrate. Observed difference between gas phase composition and gas molecules trapped in hydrate phase allows to consider these hydrates as a gas separation medium. We believe that presented results could be applicable for improvements of hydrate technology for CO2 utilization as a greenhouse gas, and hydrogen obtained from natural gas refinement transportation.

Study of apparent effective ionization coefficient in CO2 and Ar gas mixtures

Ar:CO2 gas mixtures have recently received research interest due to the possibly beneficial effects of Ar addition to CO2 for CO2 conversion using electrical discharges. For any gas discharge, knowledge of fundamental parameters, such as the effective ionization coefficient, is necessary to optimize the efficiency of the discharge for a particular application. The reduced apparent effective ionization coefficient αea/N is a measure of total ionization. αea/N is influenced by electron impact ionization, electron attachment and also by charge transfer reaction, Penning ionization, and photoionization. This study determined the αea/N of Ar:CO2 gas mixtures in the pressure range of 10–800 Torr and reduced electric field strength E/N range of 40–1200 Td utilizing a steady-state non-self-sustaining Townsend discharge. Experimental results were compared with calculations of Boltzmann equation solver BOLSIG+. Differences between measurements and calculations increased with decreasing CO2 content in the mixture down to 20%, and the differences were highest at low E/N values (below 150 Td). As the simple modification of the model, contribution of ionization of CO2 by Penning transfer from Ar* 3p53d excited states (13.86 eV) was added to the BOLSIG+ calculations, which resulted in good fit of the experimental measurements. Comparison of CO2 addition to Ar with the addition of O2 or N2 revealed that ionization of CO2 or O2 from Ar* 3p53d excited states influences ionization in Ar:CO2 and Ar:O2 mixtures but not in Ar:N2 mixtures, due to the different ionization energies of CO2, O2, and N2.

Towards net-zero: CO2 capture and biogas purification through electric potential swing desorption to achieve SDGs 7 and 13

Currently, the potential of biomethane derived from biogas is substantial, positioning it to fulfill a considerable share of the United Kingdom’s total energy needs. The primary challenge associated with raw biogas lies in purifying it to produce biomethane, a process that necessitates the removal of carbon dioxide and hydrogen sulfide. Among the various methods, adsorption of activated carbon (AC) stands out as a particularly effective and cost-efficient approach for converting biogas into biomethane, provided that the regeneration of AC proves economically viable. In this research, a segment of activated carbon was utilized to assess the adsorption properties when exposed to a gas mixture of CO2, H2S, and N2 within a regenerative activated carbon setup. This investigation encompassed the analysis of adsorption and desorption behaviors, process capacities, and the impact of regeneration. To enhance the adsorption of CO2, electro-conductive polymers (ECPs) were incorporated into the AC samples, leading to an extension in breakthrough time. Subsequent to adsorption, the electric potential swing desorption (EPSD) was employed for in situ regeneration of activated carbon samples, involving potentials of up to 30 V. The findings exhibited that the newly introduced EPSD technique considerably diminished desorption durations for both H2S and CO2. Moreover, it successfully rejuvenated the accessible adsorption sites, resulting in reduced desorption times compared to the initial breakthrough time during adsorption. Consequently, the EPSD system proves to be a promising candidate for in situ regeneration of activated carbon to eliminate CO2 and H2S from biogas. Notably, this approach offers inherent advantages over conventional methods including thermal swing adsorption (TSA) and pressure swing adsorption (PSA) in terms of regeneration. The demonstrated method underscores the potential for more efficient and economically viable cycles of adsorption and desorption, thereby enhancing the overall biogas-to-biomethane conversion process to achieve SDGs 7 and 13 for clean and green energy applications.

Comparison of gravimetry and dynamic dilution for the generation of reference gas mixtures of CO2 at atmospheric amount fraction

Carbon dioxide (CO2) is the most important greenhouse gas generated by human activities. Its concentration has been growing in the atmosphere reaching a current annual average of 410 μmol mol−1. Reliable determinations of the atmospheric CO2 concentration are of great importance for the development of models used in climate change predictions. The production of reference mixtures of known composition is a key step for the achievement of reliable data for the monitoring of greenhouse gases in atmosphere.The present work deals with a comparison of two methods for gas mixtures preparation, the first based on the gravimetric preparation of gas mixtures in high pressure cylinders and the second based on dynamic dilution, for generating gas mixtures at the desired amount fraction online.Reference mixtures of CO2 can be used for the calibration of monitoring sensors, with various applications ranging from environmental monitoring to industrial process control.

Organic-inorganic composite membrane-based transport membrane condenser: Performance of waste recovery from hot gas mixture of CO2 and water vapor

Recovering the waste heat from the stripped gas (i.e., the gas mixture of CO2 and water vapor) using the transport membrane condenser is an effective approach to reduce the regeneration heat consumption in CO2 chemical absorption process. To decrease the capital expenditure of transport membrane condenser, this study prepared an inexpensive organic–inorganic composite membrane through adding the hydroxylated boron nitride (BN-OH) into the polyvinylidene fluoride (PVDF) during membrane preparation via nonsolvent induced phase separation. Then the composite membrane was placed in a membrane cell as the transport membrane condenser to recovery the waste heat of simulated stripped gas. The results showed that when compared to the single PVDF membrane, the addition of BN-OH improves the pore uniformity, thermal conductivity, and porosity of membrane. Among all the prepared composite membranes, the composite membrane adding 5 wt% nano-sized BN-OH particles exhibits the best waste heat recovery performance. Furthermore, a decrease in the membrane thickness in addition to an increase in polyvinylpyrrolidone dosage during membrane preparation enhances the waste heat recovery performance, however deteriorates the mechanical strength of membrane. Moreover, the organic–inorganic composite membrane prepared in this study demonstrated a good stability of waste heat recovery performance during a long-term operation, showing a potential in the rich solvent-split modified carbon capture process to achieve a low capital expenditure and a high waste heat recovery performance.

Binary carbon dioxide and nitrogen adsorption on pomelo peel-derived porous sorbent

The rising concern regarding CO2 emission from fossil fueled-power plants, along with the heightened interest in repurposing biowaste has necessitated the utilization of biowaste as an adsorbent for CO2 capture. In this study, the pomelo peel-derived activated carbon (POM-AC) was investigated as a potential adsorbent for post-combustion CO2 capture application, which involves capturing CO2 from the CO2 and N2 gas mixture. The POM-AC was characterized, revealing a microporous-mesoporous structure that contains various surface functional groups including hydroxyl, carbonyl, carboxyl, and alkene groups. The strong affinity of POM-AC towards CO2 over N2 was demonstrated from the increment in the CO2 and N2 gas mixture uptake with the increase in CO2 gas compositions. The total adsorption capacity of POM-AC at ambient conditions for 100% CO2, 15% CO2, 10% CO2, and 5% CO2 is 127.8 mg/g, 55.7 mg/g, 49.1 mg/g, and 38.3 mg/g, respectively. Notably, POM-AC outperformed the commercial activated carbon (Chemiz-AC) at simulated post-combustion conditions due to POM-AC having smaller pores than Chemiz-AC. The Ideal Adsorbed Solution Theory (IAST) prediction of binary CO2 and N2 adsorption equilibria showed higher CO2 adsorption capacity than N2 at post-combustion gas compositions (5–15% CO2), which further suggests its stronger preferential of CO2 over N2. Furthermore, a relatively high CO2/N2 selectivity of 23.9 was predicted for 15% CO2 gas composition. The adsorption isotherm and kinetic analysis revealed that the surface of POM-AC is heterogenous, and the rate-controlling step of CO2 and N2 adsorption is physisorption. Coupled with the utilization of a zero-cost biowaste as an activated carbon precursor, these findings showed that POM-AC could be a promising adsorbent for post-combustion CO2 capture application.

Effect of CO2 and H2 gas mixture in cold water immersion on recovery after eccentric loading

BackgroundThe findings of previous studies support the efficacy of cold water immersion (CWI) with carbon dioxide (CO2) in enhancing muscle blood flow and maintaining aerobic performance efficiency. We hypothesize that the addition of hydrogen gas (H2), known for its antioxidant properties and role in inflammation regulation, to C-CWI can enhance recovery after eccentric exercise. Subjectsand Methods: Thirty-four healthy subjects performed a knee-extensor eccentric exercise. They were randomly allocated into four groups: control, CWI, CO2-rich CWI (C-CWI), and CO2 + H2 gas mixture CWI (CH-CWI). In the three CWI groups, all subjects were immersed in the appropriate bath at 20 °C for 20 min immediately after 60 repetitions of eccentric exercise. Before exercise and after 48 h of recovery, the subjects' maximal voluntary isometric contraction torque (MVC-ISO), maximal voluntary concentric (MVC-CON) contraction torque, countermovement jump (CMJ) height, knee flexion range of motion (ROM), muscle soreness, and muscle thickness were measured. ResultsIn the CH-CWI group only, the MVC-ISO, CMJ height, and ROM did not decrease significantly post-exercise, whereas all of these decreased in the other three groups. Muscle soreness at palpation, contraction, and stretching significantly increased post-exercise in all groups. Echo intensity and tissue hardness did not increase significantly in the CH-CWI group. ConclusionsCH-CWI stimulated recovery from impairments in MVC-ISO torque, CMJ height, knee-flexion ROM, tissue hardness, and echo intensity. These findings indicate that CH-CWI can promote recovery after eccentric exercise.

High Purity Hydrogen and Carbon Dioxide Separation with Electrochemical Pump Operation of HT-PBI Fuel Cell at 120°C

A commercially available, polybenzimidazole (PBI) membrane based electrochemical hydrogen pump (EHP) platform was thoroughly evaluated to generate a benchmark set of performance. A primary gas mixture of CO2 and H2 with a ratio of 4:1 was selected to demonstrate the performance of EHPs while addressing concerns of CO2 poisoning effect. There is no indication of significant CO poisoning as a result of reverse water gas shift reaction (RWGS), and nearly Faradaic current efficiencies were successfully achieved. It was found that humidification of the feed gas at room temperature improved polarization performance while also improving energy efficiency, thus reducing the need for tightly controlled relative humidity of feed gas. A new perspective on EHP energy efficiency calculation methodology is also provided by inclusion of the cell heating requirement into the calculation. In this manner, an overall improvement to energy efficiency nearing 20% was realized by dropping the cell temperature to 120°C while paying no significant penalty to electrochemical performance. Nearly 99.99% pure H2 and 99.93% pure CO2 were produced with a hydrogen yield of 99.34%.

Analysis of the Insulation Characteristics of Hexafluorobutene (C4H2F6) Gas and Mixture with CO2/N2 as an Alternative to SF6 for Medium-Voltage Applications

This paper investigates C4H2F6, a promising environmentally friendly insulating gas that possesses high dielectric strength and a low global warming potential. The study focuses on examining the insulation properties of C4H2F6 when combined with CO2/N2, aiming to assess its suitability as a substitute for SF6 in gas-insulated applications. Finite element analyses are performed to evaluate the field utilization factor and electric field distribution in the proposed mixture. The properties of liquefaction temperature were examined in this study to determine the optimal mixing ratio for applications that require a minimum working temperature. Extensive experimental investigations were carried out to assess the dielectric strength characteristics of the gas mixture in both uniform and quasi-uniform electric fields. It was found that pure HFO-1336mzz (E) exhibits a dielectric strength approximately 1.2–1.6 times higher than SF6. Experimental results have revealed that the insulation performance of a 30% HFO-1336mzz (E)/CO2 mixture closely resembles that of SF6, with a matching efficiency of up to 90% in a weakly uniform electric field. This remarkable performance can be attributed to a positive synergistic effect between HFO-1336mzz (E) and CO2, combined with the gas mixture’s excellent self-recoverability property. These experimental findings are further supported by finite element analysis, which confirms the observed results. The 30% HFO-1336mzz (E)/CO2 gas mixture at 0.15–0.20 MPa pressure and constant 0.6 mm air gap reveal superior insulation tolerance and less sensitivity to the electric field, confirming its promising medium-voltage engineering applications. The associated results of this research provide a critical reference for the engineering application of the alternating (AC) and direct current (DC) insulation characteristics of the HFO-1336mzz (E)/CO2 gas mixture.

Tailoring gas hydrate lattice dimensions for enhanced methane selectivity in biogas upgrading

Gas hydrates, specifically clathrate hydrates, have emerged as a potential separation medium for biogas containing methane (CH4) and carbon dioxide (CO2). However, the efficient separation of CH4 and CO2 remains challenging due to their similar cage occupation behavior within the hydrate structure. This study aimed to enhance CH4 selectivity by modifying the hydrate lattice to exclude CO2 from large cages and reduce the size of small cages through lattice engineering. To achieve this, tert-butyl alcohol (TBA) and trimethylene oxide (TMO) were employed as thermodynamic promoters, inducing strong and weak cage expansion, respectively. The results revealed that TMO hydrates, with their weak cage expansion, exhibited improved CH4 selectivity compared to TBA hydrates, which displayed strong cage expansion due to the larger size of TBA. Multi-stage separation experiments demonstrated that TMO hydrates required four unit stages, while TBA hydrates necessitated more than five unit stages to obtain purified CH4 (> 85%) from an initial gas mixture of CH4 (50%) and CO2 (50%). Additionally, TMO hydrates consistently exhibited higher separation factors than TBA hydrates in all unit stages. The findings emphasize the influence of the thermodynamic promoter's size on the separation performance of gas hydrates in separating CH4 from CH4 + CO2 mixtures. The study provides valuable insights into enhancing CH4 selectivity through lattice engineering and offers guidance in selecting suitable thermodynamic promoters for gas hydrate-based biogas upgrading applications.

Spatiotemporal features of neurovascular (un)coupling with stimulus-induced activity and hypercapnia challenge in cerebral cortex and olfactory bulb

Carbon dioxide (CO2) is traditionally considered as metabolic waste, yet its regulation is critical for brain function. It is well accepted that hypercapnia initiates vasodilation, but its effect on neuronal activity is less clear. Distinguishing how stimulus- and CO2-induced vasodilatory responses are (dis)associated with neuronal activity has profound clinical and experimental relevance. We used an optical method in mice to simultaneously image fluorescent calcium (Ca2+) transients from neurons and reflectometric hemodynamic signals during brief sensory stimuli (i.e., hindpaw, odor) and CO2 exposure (i.e., 5%). Stimuli-induced neuronal and hemodynamic responses swiftly increased within locally activated regions exhibiting robust neurovascular coupling. However, hypercapnia produced slower global vasodilation which was temporally uncoupled to neuronal deactivation. With trends consistent across cerebral cortex and olfactory bulb as well as data from GCaMP6f/jRGECO1a mice (i.e., green/red Ca2+ fluorescence), these results unequivocally reveal that stimuli and CO2 generate comparable vasodilatory responses but contrasting neuronal responses. In summary, observations of stimuli-induced regional neurovascular coupling and CO2-induced global neurovascular uncoupling call for careful appraisal when using CO2 in gas mixtures to affect vascular tone and/or neuronal excitability, because CO2 is both a potent vasomodulator and a neuromodulator.

Effects of different atmosphere on reaction behaviors of metallised burden

ABSTRACT The utilisation of metallised burden in blast furnace (BF) as a way of CO2 emission reduction has been widely considered. One of the major concerns is its reoxidation by CO2 in the upper part of BFs. In this study, the non-isothermal reaction behaviours of metallised burden with a metallisation ratio of 70% in different CO2 + CO gas mixtures were analysed. The results showed that the metallised burden can be oxidised by CO2 under sufficiently large CO2 partial pressure. In a 50%CO2 + 50%CO gas mixture, Fe was oxidised to FeO. And the reaction started at 718°C, which is much higher than the temperature in the upper shaft of BFs. The metallised burden cannot be oxidised by CO2 in the low temperature zone of BFs. During the descent of the burden, temperature increases and the reduction atmosphere strengthens in an actual BF. The CO2 partial pressure is insufficient to oxidise the metallised burden.

Separation of CH4 - CO2 gas mixture by gas hydrate crystallisation: A parametric study

In the present study a comprehensive experimental study of the CO2 gas hydrate recovery from the CH4 (81.70 mol.%) - CO2 (18.30 mol.%) experimental gas mixture was realised. The effect of the mode, temperature, pressure, and promoter on the CO2 gas hydrate recovery efficiency was investigated. The parametric study will optimise the technology of gas hydrate crystallisation to CO2 remove from natural gas. The gas mixture process separation factor and gas hydrate recovery were studied in SDS (0.30 wt%) aqueous solutions with and without THF (3.80 wt%). The separation simulation was performed for the two modes: pressure-dropping and constant pressure in the temperature range 272.15–283.15 К at the driving forces 1.00 and 2.00 MPa 8 h after the start of the gas hydrate formation. The different temperature dependence is shown for the CH4 and CO2 gas hydrate recovery in depending on the aqueous solution. The CO2 gas hydrate recovery maximum, equal to 63.92% (without THF) and 57.19% (with THF), is observed at the constant pressure separation at 272.15 K and 2.00 MPa. However, THF addition makes it possible to decrease the gas hydrate dissociation pressure of the experimental gas mixture in 7.87 times at 272.15 K. Thus, the choice of the aqueous solution was determined by the aim for the gas hydrate separation – high gas hydrate recovery (without THF) or low process pressure (with THF).

Research on Heat Dissipation Performance of Eco-friendly Gas insulated Transformer with i-C4F7N/CO2 as the Insulation Medium

Generally, the thermal conductivity of gas insulation medium is generally worse than that of liquid insulation medium. The heat dissipation problem is the key to developing large-capacity gas-insulated transformers. The traditional SF6 gas-insulated transformers are facing the challenge of upgrading and updating due to the strong greenhouse effect of SF6. As an ideal substitute gas for SF6, i-C4F7N/CO2 gas mixture is used as a new insulation medium to develop eco-friendly gas-insulated transformers. In this work, we described the structure and parameters of 10 kV GIT and measured the temperature and pressure by mounting sensors in different parts of 10 kV GIT. Further, we analyzed the heat dissipation performance of the Transformer based on the pressure and temperature data. The results show that the GNAN cooling mode may not be applicable to eco-friendly GITs with large capacities and high loads.