Use Of Gas Research Articles

The injection pattern investigation of hydrocarbon gas enhanced oil recovery in heterogeneous reservoirs

Considering the large difference in physical properties and low water flooding efficiency of heterogeneous reservoirs, the hydrocarbon gas flooding to enhance oil recovery was investigated. Through the rising bubble apparatus experiment, it was determined that the injected gas and crude oil are immiscible under formation conditions. On the other hand, the displacement experiment carried out on a long core was used to perform the effect of hydrocarbon gas flooding. According to displacement experiment, alternative injection of gas as slugs with water slugs can mobilize the residual oil in place in the reservoirs. When the gas injection rate is 0.5 cm3/min, the recovery efficiency of hydrocarbon gas flooding is highest. At the same time, the lower of water content, the better the timing of waterflooding to gas flooding. In experiments with slugs of different gas–water ratios, when the gas–water ratio is 1:1, the oil recovery efficiency is the highest. The water alternate gas in use within limit adaptation could significantly enhance the residual oil recovery and bring more economic benefits.

Gas Delivery Relevant to Human Health using Porous Materials.

Gases are essential for various applications relevant to human health, including in medicine, biomedical imaging, and pharmaceutical synthesis. However, gases are significantly more challenging to safely handle than liquids and solids. Herein, we review the use of porous materials, such as metal-organic frameworks (MOFs), zeolites, and silicas, to adsorb medicinally relevant gases and facilitate their handling as solids. Specific topics include the use of MOFs and zeolites to deliver H2S for therapeutic applications, 129Xe for magnetic resonance imaging, O2 for the treatment of cancer and hypoxia, and various gases for use in organic synthesis. This Perspective aims to bring together the organic, inorganic, medicinal, and materials chemistry communities to inspire the design of next-generation porous materials for the storage and delivery of medicinally relevant gases.

First-principles study of the effects of doping B, N, and O on the photoelectric properties of Cr adsorbed GaS.

To lessen the impact of the dangerous metal Cr, this paper applies the first principles to investigate the adsorption behavior and photoelectric properties of GaS on Cr. The effects of doped GaS on Cr adsorption behavior are investigated with four GaS systems, which are pure, boron (B)-doped, nitrogen (N)-doped, and oxygen (O)-doped, in order to maximize the characteristics of GaS for use in novel sectors, to obtain understanding of the impact of doping on the electronic structure and optical properties of GaS adsorption of Cr, as well as to promote the development of the material. Four GaS adsorbed Cr systems, pure, B-doped, N-doped, and O-doped, are optimized, and the optimized results show that the stable adsorption position of Cr on both pure and doped GaS is the top position of Ga atoms, whereas doped elements B, N, and O can promote the adsorption of Cr on GaS, and the order of the strength of this promotion is B > N > O. In this paper, molecular simulation calculations and analyses using the CASTEP module in the software Materials Studio are performed to simulate the structure optimization of GaS-adsorbed Cr materials doped with B, N, and O atoms by using the generalized gradient approximation (GGA) plane-wave pseudopotential approach [1] and the Perdew-Burke-Ernzerhof (PBE) generalized function [2]. From the convergence test, it is reasonable to set the K-point network to 4 × 4 × 1 and the truncation energy to 500eV [3]. In this paper, a 3 × 3 × 1 supercell structure with 18 S atoms and 18Ga atoms is selected. The convergence value of the iterative accuracy is 1.0e - 5eV/atom, and all the atomic forces are less than 0.02eV/Å. A vacuum layer of 16Å is also set in the C direction to avoid interlayer interactions of GaS. First, we optimize the geometry of the model and then analyze the nature of the adsorption energy and electronic structure corresponding to the model.

Thermodynamic analysis and optimization of a novel system integrating with solid oxide fuel cell-gas turbine and parabolic trough collector for using in sports buildings

This study aims at sport buildings and discussing mathematical models' applications focused on energy problems, both on the thermal and electrical sides. Methanol is a type of alcohol that can be used as an alternative fuel option. Solid oxide fuel cells are a type of fuel cell that have advantages over other types of fuel cells such as high efficiency and low emissions. Researchers are exploring the use of methanol in solid oxide fuel cells, because it can be converted into synthetic gas at certain temperatures using catalysts. This study focuses on a system that uses solar energy for combined cooling, cooling, heating, and power generation. Solar energy is a renewable and environmentally friendly source of energy. Methanol is synthesized and then converted into gases for use in solid oxide fuel cells. This process is called reforming. A fuel cell and a gas turbine system can increase power generation and provide heat for cooling with a conversion efficiency exceeding 64%, but 15% of energy is lost due to light and heat losses.

Утилізація надлишкового газу УСГК

COKE DRY COOLING PLANT EXCESS GAS UTILIZATION © S.A. Kravchenko, PhD in Technical Sciences (STATE ENTERPRISE "STATE INSTITUTE FOR DESIGNING ENTERPRISES OF COKE OVEN AND BY-PRODUCT PLANTS'' (SE "GIPROKOKS'')", 60 Sumska str., Kharkiv, 61002, Ukraine), D.V. Miroshnichenko, Doctor of Technical Sciences (National Technical University "Kharkiv Polytechnic Institute", 61002, Kharkov, Kirpichev str., 2, Ukraine) At coke-chemical enterprises, that operate coke dry cooling plants, due to the peculiarities of the technology, an excess of circulating gas is formed, which must be constantly removed from the closed circuit. This article examines two operating plants designed for the utilization of excess circulating gas, and also presents some experience of their exploitations. In particular, information is provided on the method of disposal of excess circulating gas of coke dry cooling plants in an additional boiler by burning it in a mixture with coke gas. The main equipment of the recycling unit is a KO-10 steam boiler with forced circulation and a U-shaped arrangement of heating surfaces, located in the building of the boiler coke dry cooling plant of coke batteries of one of the coke-chemical enterprises. Tests and operation of the plant confirm the possibility of producing a couple of energy parameters on it with the achievement of high environmental indicators as a result of the utilization of excess gas of the coke dry cooling plant. The second direction considered is the use of excess gas from the coke dry cooling plant as fuel. The possibility is shown of increasing its calorific value as a result of mixing circulating gas with gas of higher calorific value – in particular with blast furnace gas. It is shown that the existing positive experience of operating the mentioned installations allows recommending both directions for the utilization of excess circulating gas for use on existing and newly designed coke dry cooling plants. According to the article, the work experience, a lot of experiments and performed calculations indicate the expediency of maintaining the regime with the maximum permissible content of CO in the circulating gases during the operation of the coke dry cooling plants. This allows to increase the quality indicators of coke. The high content of CO in the circulating gases also makes it possible to significantly reduce losses from coke burning in the process of dry cooling. Keywords: coke dry cooling, recovery boiler, circulating gas, excess, utilization, additional boiler, increase in calorific value, CO content, coke quality. Corresponding author S.O. Kravchenko, e-mail: sa_kravchenko@giprokoks.com

Occupational Exposure to Halogenated Anaesthetic Gases in Hospitals: A Systematic Review of Methods and Techniques to Assess Air Concentration Levels

Objective During the induction of gaseous anaesthesia, waste anaesthetic gases (WAGs) can be released into workplace air. Occupational exposure to high levels of halogenated WAGs may lead to adverse health effects; hence, it is important to measure WAGs concentration levels to perform risk assessment and for health protection purposes. Methods A systematic review of the scientific literature was conducted on two different scientific databases (Scopus and PubMed). A total of 101 studies, focused on sevoflurane, desflurane and isoflurane exposures in hospitals, were included in this review. Key information was extracted to provide (1) a description of the study designs (e.g., monitoring methods, investigated occupational settings, anaesthetic gases in use); (2) an evaluation of time trends in the measured concentrations of considered WAGs; (3) a critical evaluation of the sampling strategies, monitoring methods and instruments used. Results Environmental monitoring was prevalent (68%) and mainly used for occupational exposure assessment during adult anaesthesia (84% of cases). Real-time techniques such as photoacoustic spectroscopy and infrared spectrophotometry were used in 58% of the studies, while off-line approaches such as active or passive sampling followed by GC-MS analysis were used less frequently (39%). Conclusions The combination of different instrumental techniques allowing the collection of data with different time resolutions was quite scarce (3%) despite the fact that this would give the opportunity to obtain reliable data for testing the compliance with 8 h occupational exposure limit values and at the same time to evaluate short-term exposures.

Experimental study of the effect of HHO gas injection on pollutants produced by a diesel engine at idle speed

In this study, with the aim of reducing the energy consumption in the production of HHO gas for use in the combustion process of diesel fuel, different modes of gas production were investigated using electrolyzers. According to previous studies, the energy consumption rate of the electrolyzer to produce a high volumetric flow of HHO gas is very high. This high rate will restrict the use of equipment such as high-capacity batteries. The effects of HHO gas injection at the idle speed of the engine at a low temperature were evaluated. Because in this situation, the engine makes high air pollution. The results showed that the percentage of CO, CO2, HC, and NOX gases decreased by 66%, 33%, 38%, and 11%, respectively. On the other hand, the amount of O2 gas in the exhaust increased by 18%. These results were reported for HHO gas injection from 10 to 45 ml/s. The performance of Group Method of Data Handling (GMDH) neural network was desirable in modeling diesel engine pollutants. Because the Root-Mean-Square Error (RMSE) criterion for all evaluated gases is less than 0.32. The GMDH neural network was used for modeling the operation of the diesel engine with HHO supplemental fuel. The GMDH results showed that this artificial network can measure all engine exhaust gases. It can be used as a sensor and virtual simulator for this diesel engine with HHO supplemental fuel.

Effect of driver gas composition on production of scaled Friedlander waveforms in an open-ended shock tube model

With the evolution of modern warfare and the increased use of improvised explosive devices (IEDs), there has been an increase in blast-induced traumatic brain injuries (bTBI) among military personnel and civilians. The increased prevalence of bTBI necessitates bTBI models that result in a properly scaled injury for the model organism being used. The primary laboratory model for bTBI is the shock tube, wherein a compressed gas ruptures a thin membrane, generating a shockwave. To generate a shock wave that is properly scaled from human to rodent subjects many pre-clinical models strive for a short duration and high peak overpressure while fitting a Friedlander waveform, the ideal representation of a blast wave. A large variety of factors have been experimentally characterized in attempts to create an ideal waveform, however we found current research on the gas composition being used to drive shock wave formation to be lacking. To better understand the effect the driver gas has on the waveform being produced, we utilized a previously established murine shock tube bTBI model in conjunction with several distinct driver gasses. In agreement with previous findings, helium produced a shock wave most closely fitting the Friedlander waveform in contrast to the plateau-like waveforms produced by some other gases. The peak static pressure at the exit of the shock tube and total pressure 5 cm from the exit have a strong negative correlation with the density of the gas being used: helium the least dense gas used produces the highest peak overpressure. Density of the driver gas also exerts a strong positive effect on the duration of the shock wave, with helium producing the shortest duration wave. Due to its ability to produce a Friedlander waveform and produce a waveform following proper injury scaling guidelines, helium is an ideal gas for use in shock tube models for bTBI.

Senator Elbert Thomas and the Hope for Industrial Equity

Senator Elbert Thomas and the Hope for Industrial Equity

Simplified sulfur-iodine cycle process to hydrogen blast furnace: Techno-economic and CO2 mitigation analysis

In iron-making plants, the carbon emission problem is significant, and the existing reduction strategies focus on hydrogen utilization. Among the hydrogen production processes, a sulfur-iodine (SI) cycle is one of the most competitive candidates and there is a potential for the modification of the process design specifically targeted for the applications on blast furnaces (BF). We suggest a design for the SI process to produce H2 gas for use as a reductant in the BF during iron smelting. We first validated the conventional SI process by using a commercial process simulator with plant data and simplified the process to increase energy efficiency, profitability, and CO2 mitigation. We calculated the energy efficiency of the various process designs and derived the unit production cost of H2. We discussed the economic feasibility of the SI process in BF applications and showed the potential to mitigate global warming. The energy efficiency of the conventional SI process was estimated to be 32% and was increased to 38% by excluding a sulfuric acid decomposer. The unit production cost was estimated to be 1.22US$ kgH2−1 for the conventional SI process, and 0.80US$ kgH2−1 for the modified SI process of sulfuric acid co-production. The economic feasibility of the SI/MSI cycles was confirmed with a calculation of an internal rate of return and net present value. Also, generated H2 was utilized as an alternative fuel in BF, with an expected coke-replacement ratio of 0.168–0.232kgCoke mH2−3, and for the environmental prospects, an annual reduction was expected to 1077ktCO2-eq in the hot metal production scale of 3.8 Mt y−1.

Reactions

OPINION Reactions ShareShare onFacebookTwitterWechatLinked InRedditEmail C&EN, 2022, 100 (1), p 5January 3, 2022Cite this:C&EN 100, 1, 5▸ Letters to the editorHydrogen as a liquidI did enjoy Michael McCoy’s case study 1 on page 18 of the Oct. 25 issue of C&EN. I and others I could name would be remiss by failing to point out that the same basic idea—that is, a reversible hydrogenation-dehydrogenation cycle to first store hydrogen in a liquid, easily transportable form and then catalytically release it as gas for use as fuel in internal combustion engines or in fuel cells—has been tried before. As noted in the article, that would theoretically allow conventionally equipped gasoline- or diesel-powered vehicles to adapt existing tank and dispensing technology and infrastructure to use H2 as a substitute for standard liquid fuels like gasoline or diesel.I initially became acquainted with this concept when Battelle Memorial Institute–Pacific Northwest National Laboratory (PNNL) was approached in 2008 or 2009 by Air Products. Air Products R&D staffs, led by Guido Pez, wanted PNNL to advance this technology to a viable demonstration stage using catalytic technology developed at Air Products and including process intensification (microchannel) technology developed by PNNL. The Air Products technology eventually was published as a series of US patents—7351395, 7101530, 7766986, and 8003073—and a Canadian patent, 2465555C, having Pez as an inventor. There may also be additional patents that I am not currently aware of.Since this was around the time of my retirement from PNNL, I am not exactly clear as to the outcome or the results of the proposed collaboration, although I did hear that both parties had agreed to a scope of work and the fees, terms, and conditions involved but that expected funding from the Department of Energy was either late in coming or eventually denied. I believe the technology has strong merit but as far as I know was not developed to a stage that would be ready for a commercial demonstration.I am glad to see that this general idea is again gaining some traction.James F. WhiteRichland, WashingtonMOFs with magnetsMitch Jacoby’s article “MOFs Have a New Trick” (C&EN, Nov. 29, 2021, page 30) reminded me that these unique materials have also caught the attention of analytical chemists.By incorporating magnetic nanoparticles into metal-organic frameworks, researchers have developed a relatively new miniaturized version of the matrix solid-phase dispersion sample-preparation technique known as magnetic dispersive micro solid-phase extraction (M-D-μSPE). The successful isolation and recovery of 15 priority pollutant polycyclic aromatic hydrocarbons at trace concentration levels from water was studied using M-D-μSPE (LCGC North Am.201836, 464).Paul R. LocontoOkemos, MichiganACS as a verbI was sad to find that the American Chemical Society has now joined technical and advertising entities in dumbing down the use of the English language (using nouns as verbs). The cover ad for C&EN had “How do you ACS?” and the back had “There is more than one way to ACS.” Would you accept such nonsense in any of your journals?I could understand it for advertisers for pizza using “This is how we pizza” since they are aiming at a general audience, who might think it “cute.” I objected to the use of “This is why we science” from a pharmaceutical company. If you want science to be a respected and accurate, factual profession, you should stop using this method of communication.Why would an association like ACS want to brand itself as illiterate? I guess it would be OK if ACS as used stood for “acting completely stupid.”William KenealyFitchburg, WisconsinACS as welcomingAnother good Comment about equity and inclusion (Nov. 15/22, 2021, page 52). I appreciated the fact that you defined equity (as opposed to equality) and illustrated clearly what that implies. Also, it is important that you pointed out what is initial privilege and the fact that recognizing it is not the same as laying blame. If we do not recognize a problem and clearly state what it is, we cannot do anything to rectify it!However, near the end you state, “I assure you that at this time, all ACS members do not consider ACS to be an inclusive and welcoming society.” This cannot be correct—surely some American Chemical Society members consider ACS to be inclusive and welcoming. I believe what you meant to say is, “I assure you that at this time, not all ACS members consider ACS to be an inclusive and welcoming society.”John FinkenbineMontreal CorrectionDec. 6, 2021, page 26: The feature story about materials advances for fusion includes a miscalculation about how much energy the National Ignition Facility experiment in August produced. The experiment produced 1.3 MJ, which could run a 60 W light bulb for 6 h, not a couple of weeks.

Gas Permeability Model for Porous Materials from Underground Coal Gasification Technology

Underground coal gasification (UCG) technology converts deep coal resources into synthesis gas for use in the production of electricity, fuels and chemicals. This study provides an overview of the systematic methods of the in situ coal gasification process. Furthermore, the model of the porous structure of coal has been presented and the gas movement taking place in the carbon matrix—which is part of the bed—has been described. The experimental tests were carried out with the use of air forced through the nozzle in the form of a gas stream spreading in many directions in a porous bed under bubbling conditions. The gas flow resistance coefficient was determined as a function of the Reynolds number in relation to the diameter of the gas flow nozzle. The proprietary calculation model was compared to the models of many researchers, indicating a characteristic trend of a decrease in the gas flow resistance coefficient with an increase in Reynolds number. The novelty of the study is the determination of the permeability characteristics of char (carbonizate) in situ in relation to melted waste rock in situ, taking into account the tortuosity and gas permeability factors for an irregularly shaped solid.

Ionic Liquids of Widely Variable Proton Activity in Relation to BH Hydrogen Storage Technologies and Novel Low-Vapor-Pressure Superacids

A common method of storing hydrogen gas for use in fuel cell applications is based on the solubility and stability of sodium borohydride in strongly basic (3 M NaOH) aqueous solutions. The release of hydrogen is accomplished by acidification of the solutions in the presence of catalysts or elevated temperatures. The importance of basicity control leads us to seek quantification of the basicity of the components important to these processes. We use available thermodynamic data to rank borohydrides relative to pure hydrides, and describe new alkali metal and ionic liquid compounds that could substitute for sodium hydroxide in the hydrogen storage technology. We then turn to the opposite, high proton activity, end of the basicity/acidity spectrum, and briefly review processes that produce protic ionic liquids of low vapor pressure but exceptional acidity. The total range of proton activities under discussion exceeds 50 orders of magnitude. Some consideration is given to possible electrochemical devices that exploit this domain in which the electrochemically generated voltage differences could exceed 3.5 V.

Effects of liquefed petroleum gas use in a turbocharged stratified injection engine using ethanol/gasoline as pilot fuel

The production of engines using turbocharged stratified injection technology has increased rapidly in recent years. In addition, the use of liquefied petroleum gas, which is an environmental and economical fuel, is increasing in vehicles. While liquefied petroleum gas cannot be used in turbocharged stratified injection engines before, liquefied petroleum gas kits have become applicable to these types of engines with the development of technology. Turbocharged stratified injection is used to provide the first ignition of liquid fuel in engines. Therefore, liquid fuel is sprayed from the injector and then added on liquefied petroleum gas to burn liquefied petroleum gas. Thus, unlike other systems, liquefied petroleum gas in use with the increase in efficiency is also provided. Alcohols (ethanol, methanol, butanol, etc.) biomass fuels are alternative fuel characteristics. There are many studies on the use of alcohols in internal combustion engines. What distinguishes this study is that turbocharged stratified injection is used as a pilot fuel to burn liquefied petroleum gas in an engine. In the study, a vehicle with a turbocharged stratified injection motor equipped with prins liquefied petroleum gas system was used. For this purpose, the effects of 5% (E5), 10% (E10), and 20% (E20) ethanol addition on engine power, engine torque and exhaust emissions were investigated. The vehicle experiments were carried out by increasing the engine speed from 500-5500 rpm in the chassis dynamometer. The findings showed that with E10+liquefied petroleum gas fuel, there is an increase in engine power and engine torque. There is also a reduction in all CO, CO2, and HC emissions.

Sputter-Grown Pd-Capped CuO Thin Films for a Highly Sensitive and Selective Hydrogen Gas Sensor

In the present work, hydrogen gas sensing properties of palladium-capped copper oxide (Pd/CuO) thin films have been investigated. The Pd/CuO thin films were deposited on glass substrate for different deposition times (10–30 min) using direct current magnetron sputtering. The Pd/CuO thin films were characterized by x-ray diffraction, field emission scanning electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy for their structural, morphological and compositional properties, respectively. The Pd/CuO thin film sensor deposited for 10 min presents a remarkable sensing performance with fast response/recovery time of 10 s/50 s for hydrogen gas at a concentration of (1000 ppm) and optimum operating temperature of 300°C. The sensor is observed to be highly selective towards hydrogen (H2) gas compared to the other gases such as carbon monoxide (CO) and ammonia (NH3). The sensor is stable under high humidity conditions (60% RH). The studied Pd/CuO thin film sensor can be used to design a simple and low-cost sensor to detect low concentrations of H2 gas for use in hydrogen-driven industries.

Thermodynamic analysis of an energy storage system based on pumped hydro combined with compressed gas for use in a solar powerplant

In this research, an energy storage system is proposed for Jarghooyeh's 10 MW photovoltaic solar powerplant. This powerplant is located on a flat plain with dry and warm climate. Therefore, conventional methods for energy storage based on pumped hydro is not suitable in this case. Hence a pumped hydro combined with compressed gas (PHCG) is used to design an energy storage system. Determination of proper values of the design parameters of the PHCG system, including volume ratio of water to gas and pre-set pressure of the pressurized vessel is conducted by investigation of the effects of different values of these parameters on the performance of the system. Using determined design parameters the PHCG system is proposed for the considered powerplant. Obtained results showed that proposed PHCG energy storage system comprising 23 high pressure vessels with a volume of 1000 m3 could supply up to 68% of energy demand of Jarghooeyeh-Olya city with 14,100 populations during peak load demand or night hours. Efficiency of charge and discharge cycle of the proposed PHCG energy storage system is found to be 79.1% and achieved overall efficiency of the system is about 42%.

Evaluation of biomass-based production of below zero emission reducing gas for the iron and steel industry

The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.

Why Do We Use the Materials and Operating Conditions We Use for Heterogeneous (Photo)Electrochemical Water Splitting?

Water splitting through the use of (photo)electrocatalysts is a carbon-free route to sustainably produce hydrogen gas for use in various applications, such as ammonia and methanol synthesis, hydrot...

Low-temperature, atmospheric pressure reverse water-gas shift reaction in dielectric barrier plasma discharge, with outlook to use in relevant industrial processes

Plasma discharges offer a direct way to convert electrical to chemical energy and to store volatile renewable energy sources. Converting CO2 in this way can contribute to reducing the greenhouse effect, and provide additional opportunity for chemical processing, e.g., on-site or on a small scale. The CO2 hydrogenation to CO via the reverse water-gas shift reaction (RWGS) generates synthesis gas for use as feedstock to different fuels and chemicals. TheRWGS reaction carried out in a Dielectric Barrier Discharge (DBD) plasma reactor benefits from operation at ambient pressure and mild temperature, as compared to the harsher conditions of conventional RWGS processing. To develop that with outlook to real-life uses, e.g., toward methanol synthesis, key performances need to be achieved; that is, i.a., a threshold CO2 conversion, a high CO selectivity at low impurity (low CH4 selectivity), and a high (H2 − CO2)/(CO + CO2) ratio (favourable for high reaction rates) as well as tolerable energy efficiency. Central plasma process parameters for this are the feed gas ratio, residence time, and uniformly distributed microdischarges. The optimisation of an individual key performance can be adverse to the other so that the process exploration is a task. This gives room to introduce new plasma operation types, and the burst mode was applied for the first time to the RWGS reaction in the present work. By this fast (millisecond) periodic switching on and off the plasma, the process temperature can be reduced as well as a better microdischarge distribution can be achieved. The residence time is not only set by the flow rate, as commonly done, but also by taking the discharge gap as an additional parameter of freedom, which also impacts the reducing distribution. As a result of relevant process conditions, at CO selectivity of 98%, 337 mmol/kWh is obtained as the energy efficiency of CO formation. Whereas the best CO2 conversion of 50% and the (H2 − CO2)/(CO + CO2) ratio of 2 were obtained at respective optimum process parameters.

Evaluation of Potential for Salt Cavern Gas Storage and Integration of Brine Extraction: Cavern Utilization, Yangtze River Delta Region

The Yangtze River delta region of China consumes a large amount of natural gas, but the current gas storage facilities of this region can provide only 19.6 × 108 m3 of natural gas for use, which will be far less than the required gas storage volume of 66.8 × 108 m3 in 2030. The reason is due to lacking suitable underground gas storage space. To meet the space demands of underground gas storage (UGS) in the Yangtze River Delta region, the feasibilities of UGS construction in salt formations including depth of mines, thickness of salt strata, distance to pipelines, and geologic safety of the salt mines are evaluated. The representative blocks of Huai’an salt mine and Fengxian salt mine are suggested as potential sites for UGS construction. To promote UGS construction operation quickly and economically, utilizing the existing caverns can be considered firstly. The evaluation indicates that the existing caverns can store about 12.91 × 108 m3 natural gas for UGS with a cavern utilization rate of 30%. To satisfy the space for residual gas storage, the idea of “integration of brine extraction and cavern utilization” is put forward; that is, salt mining enterprises carefully control the usability of newly increased cavern volume during brine extraction. The forecast shows that about 36.9% of the newly increased cavern volume is sufficient to meet the residual cavern demand of UGS to fulfill a gas store volume of 34.3 × 108 m3 in 2030 in the Yangtze River delta. This research provides an effective method to solve the space need for UGS in the Yangtze River delta; simultaneously, it also presents win–win cooperation for the utilization of abandoned caverns and energy storage.