Gas Utilization Research Articles

An iterative auction-based method for multi energy trading in a microgrid considering renewable energy uncertainties

Due to the significant strides made in renewable energy generating units, they are now an appealing choice for supplying energy with various benefits. Furthermore, the aggregation of different energy generators and resources and the rise of energy conversion facilities, like combined heat and power (CHP), have paved the way for a new category of multi-energy prosumers. This research presents an innovative model for a local energy market structure consisting of an aggregator, prosumers, electricity, gas, and heat utility grids, and consumers. The interplay between these entities is handled as an auction model with proposed bidding strategies in which each player participates to maximize their own objective function. The numerical analysis reveals the impact of the pricing strategy on the prosumers' willingness to provide more energy during peak demand periods. Furthermore, the study highlights the potential for mutually beneficial collaborations between prosumers, which leads to reduced energy costs.

Electrochemically coupled CH4 and CO2 consumption driven by microbial processes

The chemical transformations of methane (CH4) and carbon dioxide (CO2) greenhouse gases typically have high energy barriers. Here we present an approach of strategic coupling of CH4 oxidation and CO2 reduction in a switched microbial process governed by redox cycling of iron minerals under temperate conditions. The presence of iron minerals leads to an obvious enhancement of carbon fixation, with the minerals acting as the electron acceptor for CH4 oxidation and the electron donor for CO2 reduction, facilitated by changes in the mineral structure. The electron flow between the two functionally active microbial consortia is tracked through electrochemistry, and the energy metabolism in these consortia is predicted at the genetic level. This study offers a promising strategy for the removal of CH4 and CO2 in the natural environment and proposes an engineering technique for the utilization of major greenhouse gases.

Reliable sustainable management strategies for flare gas recovery: technical, environmental, modeling, and economic assessment: a comprehensive review.

The gas flaring network is an inseparable constituent commonly present in most of the oil and gas refineries and petrochemical facilities conferring reliable operational parameters. The improper disposal of burn-off gases improperly results in environmental problems and loss of economic resources. In this regard, waste to energy transforming nexus, in accord with the "carbon neutrality" term, has potentially emerged as a reasonable pathway to preserve our planet. In a transdisciplinary manner, the present review article deeply outlines the different up-to-date strategies developed to recover the emitted gases (flaring minimization) into different value-added products. To analyze the recovery potential of flare gases, different technologies, and decision-making factors have been critically reviewed to find the best recovery methods. We recommend more straightforward recovery methods despite lower profits. In this regard, electricity generation seems to be an appropriate option for application in small amounts of flaring. However, several flare gas utilization processes such as syngas manufacturing, reinjection of gas into petroleum reservoirs, and production of natural gas liquid (NGL) are also recommended as options because of their economic significance, technological viability (both onshore and offshore), and environmental benefits. Moreover, the adopted computational multi-scale data assimilation for predictive modeling of flare gas recovery scenarios has been systematically reviewed, summarized, and inspected.

Numerical simulations of CO2 absorption by MgO-based sorbent in a gas–solid fluidized bed

Given that carbon dioxide (CO2) constitutes the predominant proportion of greenhouse gas emissions, its capture, utilization and storage have always been a subject of great concern. Gas-solid fluidized bed has become one of the commonly applied equipment for the removal of CO2 from flue gases owing to its advantages such as exceptional mixing effect and substantial interfacial area between the phases. However, there is a lack of attention to the mechanism of CO2 absorption by individually-tracked moving solid sorbents as well as their effects on the decarbonization performance in a gas–solid fluidized bed. In this study, CO2 removal model by solid particles based on MgO adsorbent was established with the implementation of the shrinking-core model and each particle was tracked individually. Results validated the accuracy of the absorption model and revealed that smaller sizes of the solid absorbent, lower inlet gas velocities and larger inlet CO2 mass fractions exhibit relatively high CO2 removal efficiency. In addition, the decarbonization performance of fluidized and packed beds was compared. The packed bed exhibits more uniform gas flow and higher CO2 removal efficiency, whereas the fluidized bed provides larger interphase contact area, which facilitates the heat transfer process. Through the analysis of a series of parameters, the results provide recommendations for improving the CO2 removal efficiency and help to explore the optimal protocol for the design of bed reactors for CO2 removal.

Anesthesia for lung transplantation in children under 12 years of age: a single center experience of China

PurposeThis study aims to provide a comprehensive overview of anesthesia management strategies employed in pediatric lung transplantation.MethodsA retrospective analysis was conducted on data from 14 pediatric patients who underwent lung transplantation at the Wuxi Center between September 2019 and November 2022. Patient demographics, surgical particulars, airway management, utilization of extracorporeal support, fluid administration, blood gas and electrolyte profiles, and postoperative outcomes were systematically documented and subsequently summarized.ResultsOf the 14 patients, 7 received extracorporeal membrane oxygenation (ECMO) and 1 received cardiopulmonary bypass (CPB). The average operation time was 303 ± 53 min, with the median extubation time of 26 h. The entirety of pediatric lung transplant procedures was executed successfully, resulting in the discharge of thirteen patients postoperatively. Regrettably, one patient died due to infectious shock on the fourth postoperative day.ConclusionThe achievement of successful pediatric lung transplantation necessitates effective perioperative anesthesia management, with a focal emphasis on circulatory control. Real-time measurements serve as the cornerstone for decision-making. Proactive administration of vasoactive agents is integral to sustaining hemodynamic stability. The judicious assessment of ECMO necessity is paramount, favoring central ECMO during the surgical intervention.

Exploring Extreme Voltage Events in Hydrogen Arcs within Electric Arc Furnaces

This study highlights the potential utilization of hydrogen gas in electric arc furnaces for achieving cleaner and more sustainable steel production. The application of hydrogen offers a promising path for reducing carbon emissions, enhancing energy efficiency, and advancing the concept of “green steel”. This study employs a 2D axisymmetric induction-based model to simulate an electric arc under atmospheric pressure conditions. We conducted numerical simulations to compare compressible and incompressible models of an electric arc. The impact of compressibility on hydrogen arc characteristics such as arc velocity, temperature distribution, and voltage drop were investigated. Additionally, different applied current arcs were simulated using the compressible model. When compared to an incompressible arc, the compressible arc exhibits a higher voltage drop. This higher voltage drop is associated with lower temperatures and lower arc velocity. A rise in applied current results in an upward trend in the voltage drop and an increase in the arc radius. In addition, the increased applied current increases the probability of voltage fluctuations. The voltage fluctuations tend to become more extreme and exert more stress on the control circuit. This has an impact on emerging electric arc technologies, particularly those involving the use of hydrogen. These fluctuations affect arc stability, heat output, and the overall quality of processes. Thus, the precise prediction of voltage and the ability to stabilize the operation is critical for the successful implementation of new hydrogen technologies.

Combining Steam and Flue Gas as a Strategy to Support Energy Efficiency: A Comprehensive Review of the Associated Mechanisms.

Conventional steam injection projects have long been an iconic process in the development of heavy oil reserves; nevertheless, they face significant challenges in terms of energy efficiency, environmental compliance, and economic viability. Factors such as oil price fluctuations, the imperative for an energy transition, and the push to reduce carbon footprints are hindering new or ongoing implementations of traditional steam injection technologies. In response to these challenges, hybrid methods, such as the combination of steam and flue gas, are emerging as an opportunity to optimize thermal processes to improve oil recovery, energy efficiency, and environmental sustainability and extend reservoir productivity life. Steam injection enhances oil recovery by reducing the viscosity of crude oil, improving oil mobility and facilitating its extraction. The utilization of flue gas in steam injection processes has a significant impact on oil recovery and energy efficiency, leveraging industrial byproducts. This not only lowers operating costs but also reduces environmental emissions, aligned with energy transition trends. Incorporating the flue gas into a steam-based process in heavy oil reservoirs has emerged as a promising thermally enhanced oil recovery strategy. This work presents a comprehensive review based on experimental, numerical, and field studies of hybrid steam and flue gas technology as an EOR process. The main recovery mechanisms associated with the process are analyzed. In addition, the laboratory equipment required for experimental evaluations is presented, and reservoir modeling, kinetic and compositional effects on reservoir fluids, and the reduction in heat losses in the steam injection process are discussed. Furthermore, field implementations are reviewed to evaluate lessons learned and experiences on an operative scale. The combination of steam and flue gas represents an opportunity for carbon utilization and geological carbon sequestration. This dual functionality underscores its potential to enhance oil recovery and address carbon-related environmental concerns.

Insight into the role of lanthanide metal oxides on the carbon deposition resistance of Ni/MSS catalysts for dry reforming of methane

Dry reforming of methane (DRM) can well convert CO2 and CH4 into syngas to further synthesize valuable chemicals, thereby realizing the resource utilization of greenhouse gases. However, the sintering and carbon deposition vulnerabilities of Ni-based dry reforming catalysts prevent them from being commercialized. The ethylene glycol impregnation method was used in this study to create a group of Ni/MSS catalysts added with lanthanide metal oxides (CeO2、La2O3、Sm2O3、Nd2O3). A range of characterization techniques were employed to examine the impact on the resistance to carbon deposition and sintering. Studies have shown that lanthanide metal oxides enhance the metal support interaction, promote active metal Ni dispersion and reduce Ni particle size. Meanwhile, the catalyst's alkali strength and basic site count both rise, and a large number of surface oxygen vacancies are produced, among which CeO2 has the most obvious effect. As a result, the catalyst's activity and resistance to carbon deposition and sintering are greatly increased, while also inhibiting the degree of graphitization of carbon deposition. According to the kinetic studies, the catalyst containing lanthanide metal oxides had an apparent activation energy for CH4 and CO2 that was lower than the Ni/MSS catalyst.

Water-participated mild oxidation of ethane to acetaldehyde

The direct conversion of low alkane such as ethane into high-value-added chemicals has remained a great challenge since the development of natural gas utilization. Herein, we achieve an efficient one-step conversion of ethane to C2 oxygenates on a Rh1/AC-SNI catalyst under a mild condition, which delivers a turnover frequency as high as 158.5 h−1. 18O isotope-GC–MS shows that the formation of ethanol and acetaldehyde follows two distinct pathways, where oxygen and water directly participate in the formation of ethanol and acetaldehyde, respectively. In situ formed intermediate species of oxygen radicals, hydroxyl radicals, vinyl groups, and ethyl groups are captured by laser desorption ionization/time of flight mass spectrometer. Density functional theory calculation shows that the activation barrier of the rate-determining step for acetaldehyde formation is much lower than that of ethanol, leading to the higher selectivity of acetaldehyde in all the products.

A Review of Residual Pressure Utilization of Natural Gas

Natural gas needs to be depressurized before wellhead to gas gathering station or long-distance pipeline to users. At present, choking technique is widely used at wellhead and pressure regulating station, which will cause a lot of energy loss. Considerable economic and social benefits will be generated, if these residual pressures can be recycled. In this article, the pressure energy contained in the natural gas wellhead and pressure regulating valve station will be calculated based on exergy analysis. The technology and present situation of residual pressure utilization of natural gas are summarized. The existing problems and future research directions in the process of residual pressure utilization are pointed out through cases. At present, there are many studies on the use of residual pressure in the pressure regulating station, but there are relatively few studies in the natural gas wellhead. Residual pressure utilization technology improves energy utilization efficiency and makes an important contribution to energy conservation and emission reduction.

Analysis of an efficient liquified natural gas utilization cascade Brayton cycle and an improved cold energy recovery evaluation criterion

The cold energy utilization of liquified natural gas is a promising solution for electricity generation systems to raise power output. In order to enhance cold energy recovery performance, here we propose a cascade Brayton cycle, which can efficiently utilize the waste heat from gas turbine and the cold energy of liquefied natural gas. The temperature pinch in natural gas evaporator is successfully reduced by adopting helium as the working fluid. The optimal working condition is determined through parametric sensitivity analysis, and the exergy and economic performance is assessed and compared. The design case outperforming high energy efficiency (68.61 %), competitive exergy efficiency (58.51 %) and excellent levelized cost of electricity (0.0481$·(kW·h)−1). Moreover, the exergy destruction in natural gas evaporator reduced by 4.05 MW, resulting in 23.2 % improvement compared to conventional systems. Simultaneously, a modified criterion of “real specific work contributed per kg/s liquified natural gas” is proposed, which provides a more accurate cold energy recovery evaluation method for cold energy utilization power systems. The comparison of reported cold energy utilization systems are conducted based on the modified criterion, and our model delivers the best result among them.

Numerical investigation on the erosion behavior of the honeycomb H-type finned tube heat exchanger via the discrete particle method

Serious erosion problem of the heat exchanger directly affects the safe and steady operation of waste heat utilization systems. Herein, a honeycomb H-type finned tube heat exchanger for waste heat utilization of dusty flue gas was proposed, and the collision and erosion behaviors of fly ash particles were numerically predicted via the discrete particle method (DPM). Firstly, the single factor analysis was used to investigate the effects of each structural parameter on the erosion rate. Then, the range analysis of different levels of different structural parameters was carried out via orthogonal test method. Finally, the prediction correlations of erosion rates were obtained based on multiple regression method. The results shows that the oblique tube pitch and fin pitch are negatively correlated with the erosion rate, while the slit width, fin height and fin thickness are positively correlated with the erosion rate. Among them, the fin pitch has the most significant impact on the erosion rate, while the effect of oblique tube pitch is the least. The optimized case (A4B2C3D1E4) was obtained by orthogonal experimental design. Compared with the baseline case, the maximum erosion rate of the five observation points in the optimized case decreases by the average of 33.74% with the maximum reduction of 36.32%, while the average erosion rate is reduced by the average of 37.57% and the maximum of 40.58%. The above results are contributed to the optimization of anti-erosion performance of high dust-containing flue gas waste heat utilization system and the development of efficient heat exchangers.

Study on separation of CO2 condensation from natural gas based on cellular automaton method

ABSTRACT The CO2-containing natural gas is increasing, and there is an urgent need for green treatment of natural gas containing CO2 to realize the utilization of natural gas. Conventional natural gas decarbonization methods have drawbacks such as non-environmental friendliness, and the low-temperature condensation separation of carbon dioxide (snowing-separation) method as a green method of carbon capture is proposed in this paper. Aiming at the characteristics of CO2 condensation in the snowing-separation process, the growth process of CO2 crystals is obtained by simulation using the CA (Cellular Automata) method and finds that the effect of supersaturation on the growth of CO2 crystals is exponential. The snowing-separation process at .5 MPa is analyzed, and it is found that the condensation range is 158.51 K–173.86 K, the upper limit of CO2 mole fraction in natural gas is 10.1%, and the minimum separation time is 8.65 × 10−8s. Analyzing the influencing factors of CO2 separation efficiency, combining the simulation results with the experimental results, the maximum relative error is 13.93%, which can better predict the snowing-separation technology of CO2 in natural gas, and then promote the development of efficient low-temperature carbon capture process.

Reversible Carbon Dioxide/Lithium Oxalate Regulation toward Advanced Aprotic Lithium Carbon Dioxide Battery.

Li-CO2 batteries have received significant attention owing to their advantages of combining greenhouse gas utilization and energy storage. However, the high kinetic barrier between gaseous CO2 and the Li2CO3 product leads to a low operating voltage (<2.5 V) and poor energy efficiency. In addition, the reversibility of Li2CO3 has always been questioned owing to the introduction of more decomposition paths caused by its higher charging plateau. Here, a novel "trinity" Li-CO2 battery system was developed by synergizing CO2, soluble redox mediator (2,2,6,6-tetramethylpiperidoxyl, as TEM RM), and reduced graphene oxide electrode to enable selective conversion of CO2 to Li2C2O4. The designed Li-CO2 battery exhibited an output plateau reaching up to 2.97 V, higher than the equilibrium potential of 2.80 V for Li2CO3, and an ultrahigh round-trip efficiency of 97.1 %. The superior performance of Li-CO2 batteries is attributed to the TEM RM-mediated preferential growth mechanism of Li2C2O4, which enhances the reaction kinetics and rechargeability. Such a unique design enables batteries to cope with sudden CO2-deficient environments, which provides an avenue for the rationally design of CO2 conversion reactions and a feasible guide for next-generation Li-CO2 batteries.

Reversible Carbon Dioxide/Lithium Oxalate Regulation toward Advanced Aprotic Lithium Carbon Dioxide Battery

AbstractLi−CO2 batteries have received significant attention owing to their advantages of combining greenhouse gas utilization and energy storage. However, the high kinetic barrier between gaseous CO2 and the Li2CO3 product leads to a low operating voltage (&lt;2.5 V) and poor energy efficiency. In addition, the reversibility of Li2CO3 has always been questioned owing to the introduction of more decomposition paths caused by its higher charging plateau. Here, a novel “trinity” Li−CO2 battery system was developed by synergizing CO2, soluble redox mediator (2,2,6,6‐tetramethylpiperidoxyl, as TEM RM), and reduced graphene oxide electrode to enable selective conversion of CO2 to Li2C2O4. The designed Li−CO2 battery exhibited an output plateau reaching up to 2.97 V, higher than the equilibrium potential of 2.80 V for Li2CO3, and an ultrahigh round‐trip efficiency of 97.1 %. The superior performance of Li−CO2 batteries is attributed to the TEM RM‐mediated preferential growth mechanism of Li2C2O4, which enhances the reaction kinetics and rechargeability. Such a unique design enables batteries to cope with sudden CO2‐deficient environments, which provides an avenue for the rationally design of CO2 conversion reactions and a feasible guide for next‐generation Li−CO2 batteries.

INCREASING THE ENERGY EFFICIENCY OF FURNACES FOR PROCESSING SECONDARY ALUMINIUM

The article examines the current state and prospects of aluminum production in Ukraine and the world. It is shown that the production of secondary aluminum in Ukraine is economically feasible and its share is constantly increasing. The analysis of information sources showed that the demand for aluminum is constantly growing, but due to the increase in energy prices, the cost of production has increased significantly, which has led to a decrease in the volume of its production. Therefore, it is necessary to implement measures to improve the production process, which will allow to increase the level of energy saving in the production of metal. An analysis of the heat balance of the melting furnace for the production of secondary aluminum was carried out. The analysis of the heat balance showed that in the production process there are significant energy losses due to the insufficient use of heat in the technological process, including the heat of the combustion products, which is either not used effectively or not used at all. The main methods of increasing the energy efficiency of melting furnaces are considered and a list of measures to improve their operation is proposed, which will reduce the cost of metal production. Schemes for heat utilization of waste gases from melting furnaces are calculated and designed. The heat balance of the furnace before and after modernization was compiled. Calculations of the heating surface of the recuperator-air heater have been performed.

Evaluation of by-product-gas utilization options for carbon reduction at an integrated iron and steel mill

The comprehensive utilization of steel mill by-product gases is an important method for achieving climate goals. In this study, a comprehensive model is proposed for analyzing carbon-emission reduction strategies of by-product gases comprehensive utilization system at an integrated iron and steel mill. The model is used to explore carbon-emission reduction performance applying blast furnace with top-gas recycling (TGR-BF) and carbon capture and storage (CCS) applications, as well as consequent influence on steam and power cogeneration system (SPCS) operation. Carbon-emission intensity, total emission reduction and unit reduction cost are used to evaluate the carbon reduction result of by-product gases comprehensive utilization system. The results of the study indicate that the upgrade of SPCS can achieve an emission reduction of 311,200 tCO2, and the carbon-emission intensity of the power and heat supply can be reduced by 0.14 tCO2/104 kWh and 0.02 tCO2/GJ, respectively. After TGR-BF technology is applied, the total emission reduction peaks at the top-gas recovery rate of 6%, which is 85,100 tCO2. The unit reduction cost is also minimized at the top-gas recovery rate of 6%. Sensitivity analysis indicates that the reduction of power price significantly reduces the unit reduction cost.

Predicting Ghana’s Daily Natural Gas Consumption Using Time Series Models

In recent years, natural gas utilisation has seen a considerable increase because, it presents an alternative energy source that is reliable, economical and environmentally friendly for consumers. In Ghana, natural gas consumption has over the years increased due to mainly the rise in industrial and residential demands. Accurate prediction of natural gas consumption will provide stakeholders with vital information needed for planning and making informed policy decisions. This paper explores the Autoregressive Integrated Moving Average (ARIMA) and Seasonal Autoregressive Integrated Moving Average (SARIMA) to predict Ghana&amp;apos;s daily natural gas consumption. The data employed for the study is daily natural gas consumption in Ghana from 2020 to 2022. The results show that both ARIMA and SARIMA models can predict the consumption of natural gas in Ghana with a good degree of accuracy. The SARIMA model slightly outperforms the ARIMA model, with a Root Mean Square Error (RMSE) of 22.25 and a Mean Absolute Percentage Error (MAPE) of 6.96%, compared to an RMSE of 23.27 and a MAPE of 7.29% for the ARIMA model. The model forecast suggests a steady natural gas consumption in Ghana but with some intermittent fluctuations.

A high-precision experimental measurement system and method for the parahydrogen concentration and the Ortho-Para hydrogen catalyst's catalytic performance

An experimental system that combines the measurement of parahydrogen concentration with the assessment of ortho-para hydrogen catalyst's catalytic performance was created for this investigation. The concentration of parahydrogen was detected by a thermal conductivity detector integrated into the gas chromatograph. The catalyst sample and the generator of standard gas were integrated into one experimental setup for easier operation. Meanwhile, a new method for catalytic performance evaluation of ortho-para hydrogen catalyst was developed based on this system. This method can decrease test time and yield more valuable test results than the conventional way. Throughout the experiments, the system's dependability was increased by optimizing the utilization of the carrier gas. The deviation analysis and repeatability verification of the relevant test data showed that the relative standard deviation was less than 0.35% and the mean value of the variation coefficient was less than 0.20%, which demonstrated the method had high accuracy, stability, and reliability. Further studies have shown that the catalysts should be densely packed inside the converter and kept out of the air to maximize their catalytic activity. These pertinent findings regarding the application of ortho-parahydrogen catalysts in this study can guide the design of the ortho-parahydrogen converter in actual hydrogen liquefiers. Moreover, the method and the procedure proposed in this study may contribute to the optimization of the ortho-parahydrogen catalyst production process as well as the calibration of the parahydrogen concentration in liquid hydrogen products.

Elastomers mechanically reinforced and toughened with CO2 gas

Gas-responsive polymers have recently attracted considerable interest as unconventional smart materials that provide a new path toward the utilization of specific gases including CO2. Herein, we report gas-responsive elastomers that enhance mechanical properties, such as modulus, strength, stretchability, and toughness with CO2 gas. Various types of amine groups are introduced into polydimethylsiloxane elastomers to achieve the gas-induced mechanical reinforcement. In these elastomers, the amines form ionic crosslinks with CO2 gas that mechanically strengthen the materials. Furthermore, nanodomains formed via microphase separation of the ionic components behave similarly to viscoelastic nanofillers that dissipate a large amount of energy during deformation, thereby remarkably toughening the elastomers. Surprisingly, the fracture energy of the elastomer with diamine increases ~35 times in CO2 gas compared with that in N2 gas. Furthermore, the elastomers sensitively respond even to CO2 gas concentrations as low as 10 % and are remarkably toughened. Our design concept is widely applicable to the CO2 reinforcement of other polymers, such as polyethylene.