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Gases
Number of Followers: 5  Open Access journalISSN (Online) 2673-5628 Published by MDPI  [258 journals]
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- Gases, Vol. 4, Pages 133-152: Morphology Behavior of Polysulfone Membranes
Made from Sustainable Solvents
Authors: Steven Kluge, Karla Hartenauer, Murat Tutuş
First page: 133
Abstract: In a previous study, we demonstrated a change in membrane morphology and gas separation performance by varying the recipe of a casting solution based on polysulfone in a certain solvent system. Although all results were reproducible, all used solvents were harmful and not sustainable. In this study, the solvents tetrahydrofuran (THF) and N,N-dimethylacetamide (DMAc) are replaced by the more sustainable solvents 2-methyl-tetrahydrofuran (2M-THF), N-butyl pyrrolidinone (NBP) and cyclopentyl methyl ether (CPME). The gas permeation performance and, for the first time, morphology of the membranes before and after solvent replacement were determined and compared by single gas permeation measurements and SEM microscopy. It is shown that THF can be replaced by 2M-THF and NBP without decreasing the gas permeation performance. With CPME replacing THF, no membranes were formed. Systems with 2M-THF as a THF alternative showed the best gas permeation results. Permeances for the tested gases oxygen (O2), nitrogen (N2), carbon dioxide (CO2) and methane (CH4) were 5.91 × 10−2, 8.84 × 10−3, 4.00 × 10−1 and 1.00 × 10−2 GPU, respectively. Permselectivities of those membranes for the gas pairs O2/N2, CO2/N2 and CO2/CH4 were 6.7, 38.3 and 34.0, respectively. When also replacing DMAc in the solvent system, no or only porous membranes were obtained, even if the precipitation procedure was adjusted. These findings indicate that a complete replacement of the solvent system without affecting the membrane morphology or gas permeation performance is not possible. By varying the temperature of the precipitation bath, the formation of mechanically stable PSU membranes is possible only if THF is replaced by 2M-THF.
Citation: Gases
PubDate: 2024-06-25
DOI: 10.3390/gases4030008
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 153-173: Carbon Market for Climate Projects in
Russia: An Overview of Nature-Based and Technological Carbon Offsets
Authors: Tatiana Nevzorova
First page: 153
Abstract: Climate projects can become one of the key tools for decarbonization in Russia. They have powerful potential in terms of solving the problems of reducing emissions and increasing the absorption of greenhouse gases, as well as monetization potential for businesses. Despite the geopolitical crisis and sanctions imposed on Russia, certain opportunities for implementing climate projects have remained accessible. This study aims to provide a comprehensive analysis of the current status, including the regulations and approved methodologies, prospects, and challenges for climate projects in the carbon market in Russia. It also offers an overview of international carbon market mechanisms and analyses the advantages and disadvantages of the nature-based and technological solutions of climate projects for carbon sequestration. This, in turn, can facilitate the realization of future strategies for realizing the bigger potential of Russian climate projects in the domestic and international carbon markets. This research also provides up-to-date data on the current situation of the carbon market in Russia.
Citation: Gases
PubDate: 2024-07-08
DOI: 10.3390/gases4030009
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 174-190: Real Driving Emissions—Event Detection
for Efficient Emission Calibration
Authors: Sascha Krysmon, Johannes Claßen, Marc Düzgün, Stefan Pischinger
First page: 174
Abstract: The systematic analysis of measurement data allows a large amount of information to be obtained from existing measurements in a short period of time. Especially in vehicle development, many measurements are performed, and large amounts of data are collected in the process of emission calibration. With the introduction of Real Driving Emissions Tests, the need for targeted analysis for efficient and robust calibration of a vehicle has further increased. With countless possible test scenarios, test-by-test analysis is no longer possible with the current state-of-the-art in calibration, as it takes too much time and can disregard relevant data when analyzed manually. In this article, therefore, a methodology is presented that automatically analyzes exhaust measurement data in the context of emission calibration and identifies emission-related critical sequences. For this purpose, moving analyzing windows are used, which evaluate the exhaust emissions in each sample of the measurement. The detected events are stored in tabular form and are particularly suitable for condensing the collected measurement data to a required amount for optimization purposes. It is shown how different window settings influence the amount and duration of detected events. With the example used, a total amount of 454 events can be identified from 60 measurements, reducing 184,623 s of measurements to a relevant amount of 12,823 s.
Citation: Gases
PubDate: 2024-07-12
DOI: 10.3390/gases4030010
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 191-204: Experimental Optimization of Natural Gas
Injection Timing in a Dual-Fuel Marine Engine to Minimize GHG Emissions
Authors: Luigi De Simio, Luca Marchitto, Sabato Iannaccone, Vincenzo Pennino, Nunzio Altieri
First page: 191
Abstract: Phased injection of natural gas into internal combustion marine engines is a promising solution for optimizing performance and reducing harmful emissions, particularly unburned methane, a potent greenhouse gas. This innovative practice distinguishes itself from continuous injection because it allows for more precise control of the combustion process with only a slight increase in system complexity. By synchronizing the injection of natural gas with the intake and exhaust valve opening and closing times while also considering the gas path in the manifolds, methane release into the atmosphere is significantly reduced, making a substantial contribution to efforts to address climate change. Moreover, phased injection improves the efficiency of marine engines, resulting in reduced overall fuel consumption, lower fuel costs, and increased ship autonomy. This technology was tested on a single-cylinder, large-bore, four-stroke research engine designed for marine applications, operating in dual-fuel mode with diesel and natural gas. Performance was compared with that of the conventional continuous feeding method. Evaluation of the effect on equivalent CO2 emissions indicates a potential reduction of up to approximately 20%. This reduction effectively brings greenhouse gas emissions below those of the diesel baseline case, especially when injection control is combined with supercharging control to optimize the air–fuel ratio. In this context, the boost pressure in DF was reduced from 3 to 1.5 bar compared with the FD case.
Citation: Gases
PubDate: 2024-07-16
DOI: 10.3390/gases4030011
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 205-223: Portable Biogas Digester: A Review
Authors: Yolanda Mapantsela, Patrick Mukumba, KeChrist Obileke, Ndanduleni Lethole
First page: 205
Abstract: To reduce and convert biodegradable waste into energy-rich biogas, anaerobic digestion technology is usually employed. Hence, this takes place inside the biogas digester. Studies have revealed that these digesters are designed and constructed using bricks, cement, and metal; often require a large footprint; and are bulky and expensive. The innovation of portable biogas digesters has come into the market to address these challenges. This present review provides an overview of the in-depth and comprehensive information on portable biogas digesters in the literature. Areas covered in the review include the modification of the biogas digester design, the need for a portable biogas digester, recent studies on the factors affecting the performance of portable biogas digesters, and specific assumptions taken into consideration for designing any portable biogas digester. Convincingly, portable biogas digesters appeal to small rural families because of their ease of operation, maintenance, and ability to save space. The material for the construction and comparison of the portable biogas digester with other designs and the economic feasibility of the system were also reviewed. Implications: The full-scale design, fabrication, and utilization of a portable biogas digester are viable but not widely employed compared to other designs. However, there is a lack of readily available information on the portable design of biogas digesters. This review presents various aspects relating to portable biogas digesters and the quality of biogas produced. Therefore, the review suits audiences in energy process design and engineers, energy researchers, academics, and economists.
Citation: Gases
PubDate: 2024-08-01
DOI: 10.3390/gases4030012
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 224-235: The Market for Low-Carbon-Intensity Ammonia
Authors: Haoying Wang, Ning Lin, Mariam Arzumanyan
First page: 224
Abstract: As carbon capture and storage (CCS) technologies mature, the concept of a low-carbon or net-zero-carbon economy becomes more and more feasible. While many chemical and energy products do not contain carbon in their compounds, the upstream production process does. An added CCS module allows the removal of carbon emissions from the production process, which expands the value chain. This paper focuses on one of such commodities—low-carbon-intensity ammonia (LCIA). Even though ammonia is carbon-free in its final product, it is commonly made from natural gas, and the production process could generate significant carbon emissions. The idea of LCIA is to reduce the carbon footprint of the ammonia production process (e.g., blue ammonia) or eliminate carbon from the production process (e.g., green ammonia via electrolysis) so that the entire supply chain is decarbonized. The goal of this paper is two-fold. We first explore the US domestic market and the international market for LCIA. We then discuss relevant federal and local policies that could help grow markets for LCIA. The agricultural sector will be the center of the discussion, which consumes an estimated 70–90% of the global ammonia supply as fertilizers. The paper also examines other potential uses of LCIA, such as alternative fuels for decarbonizing agricultural machinery and transportation sectors. Finally, we argue that developing a comprehensive LCIA value chain, supported by dedicated policy measures and broad stakeholder engagement, is critical for materializing the potential of LCIA in contributing to a climate-resilient and sustainable economy.
Citation: Gases
PubDate: 2024-08-01
DOI: 10.3390/gases4030013
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 236-252: Estimating Total Methane Emissions from the
Denver-Julesburg Basin Using Bottom-Up Approaches
Authors: Stuart N. Riddick, Mercy Mbua, Abhinav Anand, Elijah Kiplimo, Arthur Santos, Aashish Upreti, Daniel J. Zimmerle
First page: 236
Abstract: Methane is a powerful greenhouse gas with a 25 times higher 100-year warming potential than carbon dioxide and is a target for mitigation to achieve climate goals. To control and curb methane emissions, estimates are required from the sources and sectors which are typically generated using bottom-up methods. However, recent studies have shown that national and international bottom-up approaches can significantly underestimate emissions. In this study, we present three bottom-up approaches used to estimate methane emissions from all emission sectors in the Denver-Julesburg basin, CO, USA. Our data show emissions generated from all three methods are lower than historic measurements. A Tier 1/2 approach using IPCC emission factors estimated 2022 methane emissions of 358 Gg (0.8% of produced methane lost by the energy sector), while a Tier 3 EPA-based approach estimated emissions of 269 Gg (0.2%). Using emission factors informed by contemporary and region-specific measurement studies, emissions of 212 Gg (0.2%) were calculated. The largest difference in emissions estimates were a result of using the Mechanistic Air Emissions Simulator (MAES) for the production and transport of oil and gas in the DJ basin. The MAES accounts for changes to regulatory practice in the DJ basin, which include comprehensive requirements for compressors, pneumatics, equipment leaks, and fugitive emissions, which were implemented to reduce emissions starting in 2014. The measurement revealed that normalized gas loss is predicted to have been reduced by a factor of 20 when compared to 10-year-old normalization loss measurements and a factor of 10 less than a nearby oil and production area (Delaware basin, TX); however, we suggest that more measurements should be made to ensure that the long-tail emission distribution has been captured by the modeling. This study suggests that regulations implemented by the Colorado Department of Public Health and Environment could have reduced emissions by a factor of 20, but contemporary regional measurements should be made to ensure these bottom-up calculations are realistic.
Citation: Gases
PubDate: 2024-08-05
DOI: 10.3390/gases4030014
Issue No: Vol. 4, No. 3 (2024)
- Gases, Vol. 4, Pages 41-58: Thermodynamic Analysis of Low-Emission
Offshore Gas-to-Wire Firing CO2-Rich Natural Gas: Aspects of Carbon
Capture and Separation Systems
Authors: Alessandra de Carvalho Reis, Ofélia de Queiroz Fernandes Araújo, José Luiz de Medeiros
First page: 41
Abstract: Despite the growth of renewable energy, fossil fuels dominate the global energy matrix. Due to expanding proved reserves and energy demand, an increase in natural gas power generation is predicted for future decades. Oil reserves from the Brazilian offshore Pre-Salt basin have a high gas-to-oil ratio of CO2-rich associated gas. To deliver this gas to market, high-depth long-distance subsea pipelines are required, making Gas-to-Pipe costly. Since it is easier to transport electricity through long subsea distances, Gas-to-Wire instead of Gas-to-Pipe is a more convenient alternative. Aiming at making offshore Gas-to-Wire thermodynamically efficient without impacting CO2 emissions, this work explores a new concept of an environmentally friendly and thermodynamically efficient Gas-to-Wire process firing CO2-rich natural gas (CO2 > 40%mol) from high-depth offshore oil and gas fields. The proposed process prescribes a natural gas combined cycle, exhaust gas recycling (lowering flue gas flowrate and increasing flue gas CO2 content), CO2 post-combustion capture with aqueous monoethanolamine, and CO2 dehydration with triethylene glycol for enhanced oil recovery. The two main separation processes (post-combustion carbon capture and CO2 dehydration) have peculiarities that were addressed at the light shed by thermodynamic analysis. The overall process provides 534.4 MW of low-emission net power. Second law analysis shows that the thermodynamic efficiency of Gas-to-Wire with carbon capture attains 33.35%. Lost-Work analysis reveals that the natural gas combined cycle sub-system is the main power destruction sink (80.7% Lost-Work), followed by the post-combustion capture sub-system (14% Lost-Work). These units are identified as the ones that deserve to be upgraded to rapidly raise the thermodynamic efficiency of the low-emission Gas-to-Wire process.
Citation: Gases
PubDate: 2024-03-25
DOI: 10.3390/gases4020003
Issue No: Vol. 4, No. 2 (2024)
- Gases, Vol. 4, Pages 59-73: Towards the Isothermal Gas Compression—A
Novel Finned Piston-Cylinder with Increased Efficiency
Authors: Alfred Rufer
First page: 59
Abstract: In this paper, a novel concept of a finned piston system is presented and analyzed in which the compression heat is continuously extracted from the compression chamber. The resulting compression characteristic moves in the direction of an isothermal process, reducing the temperature of the compressed fluid in the compression chamber and reducing the necessary mechanical work required to carry out the process. The finned piston concept consists in an integrated heat exchanger inside of the chamber that is constituted of imbricated flat fins placed on the stator part and on the mobile piston. The internal heat exchange on the surface is strongly increased in comparison with a classical piston/cylinder. The energetic performance of the new system is evaluated with the help of simulation. The pressures, forces, and temperature of the compressed gas are simulated as well as the mechanical work needed. The different curves are compared with the system’s adiabatic and isothermal characteristics.
Citation: Gases
PubDate: 2024-04-08
DOI: 10.3390/gases4020004
Issue No: Vol. 4, No. 2 (2024)
- Gases, Vol. 4, Pages 74-96: Transitioning to a Hydrogen Economy: Exploring
the Viability of Adapting Natural Gas Pipelines for Hydrogen Transport
through a Case Study on Compression vs. Looping
Authors: Abubakar Jibrin Abbas, Salisu Kwalami Haruna, Martin Burby, Idoko Job John, Kabir Hassan Yar’Adua
First page: 74
Abstract: The growing importance of hydrogen as an energy carrier in a future decarbonised energy system has led to a surge in its production plans. However, the development of infrastructure for hydrogen delivery, particularly in the hard-to-abate sectors, remains a significant challenge. While constructing new pipelines entails substantial investment, repurposing existing pipelines offers a cost-effective approach to jump-starting hydrogen networks. Many European countries and, more recently, other regions are exploring the possibility of utilising their current pipeline infrastructure for hydrogen transport. Despite the recent efforts to enhance the understanding of pipeline compatibility and integrity for hydrogen transportation, including issues such as embrittlement, blend ratios, safety concerns, compressor optimisation, and corrosion in distribution networks, there has been limited or no focus on pipeline expansion options to address the low-energy density of hydrogen blends and associated costs. This study, therefore, aims to explore expansion options for existing natural gas high-pressure pipelines through additional compression or looping. It seeks to analyse the corresponding cost implications to achieve an affordable and sustainable hydrogen economy by investigating the utilisation of existing natural gas pipeline infrastructure for hydrogen transportation as a cost-saving measure. It explores two expansion strategies, namely pipeline looping (also known as pipeline reinforcement) and compression, for repurposing a segment of a 342 km × 36 inch existing pipeline, from the Escravos–Lagos gas pipeline system (ELPS) in Nigeria, for hydrogen transport. Employing the Promax® process simulator tool, the study assesses compliance with the API RP 14E and ASME B31.12 standards for hydrogen and hydrogen–methane blends. Both expansion strategies demonstrate acceptable velocity and pressure drop characteristics for hydrogen blends of up to 40%. Additionally, the increase in hydrogen content leads to heightened compression power requirements until approximately 80% hydrogen in the blends for compression and a corresponding extension in looping length until around 80% hydrogen in the blend for looping. Moreover, the compression option is more economically viable for all investigated proportions of hydrogen blends for the PS1–PS5 segment of the Escravos–Lagos gas pipeline case study. The percentage price differentials between the two expansion strategies reach as high as 495% for a 20% hydrogen proportion in the blend. This study offers valuable insights into the technical and economic implications of repurposing existing natural gas infrastructure for hydrogen transportation.
Citation: Gases
PubDate: 2024-04-30
DOI: 10.3390/gases4020005
Issue No: Vol. 4, No. 2 (2024)
- Gases, Vol. 4, Pages 97-116: Combustion Diagnosis in a Spark-Ignition
Engine Fueled with Syngas at Different CO/H2 and Diluent Ratios
Authors: Santiago Martinez-Boggio, Pedro Teixeira Lacava, Felipe Solferini de Carvalho, Pedro Curto-Risso
First page: 97
Abstract: The gasification of residues into syngas offers a versatile gaseous fuel that can be used to produce heat and power in various applications. However, the application of syngas in engines presents several challenges due to the changes in its composition. Such variations can significantly alter the optimal operational conditions of the engines that are fueled with syngas, resulting in combustion instability, high engine variability, and misfires. In this context, this work presents an experimental investigation conducted on a port-fuel injection spark-ignition optical research engine using three different syngas mixtures, with a particular focus on the effects of CO/H2 and diluent ratios. A comparative analysis is made against methane, considered as the baseline fuel. The in-cylinder pressure and related parameters are examined as indicators of combustion behavior. Additionally, 2D cycle-resolved digital visualization is employed to trace flame front propagation. Custom image processing techniques are applied to estimate flame speed, displacement, and morphological parameters. The engine runs at a constant speed (900 rpm) and with full throttle like stationary engine applications. The excess air–fuel ratios vary from 1.0 to 1.4 by adjusting the injection time and the spark timing according to the maximum brake torque of the baseline fuel. A thermodynamic analysis revealed notable trends in in-cylinder pressure traces, indicative of differences in combustion evolution and peak pressures among the syngas mixtures and methane. Moreover, the study quantified parameters such as the mass fraction burned, combustion stability (COVIMEP), and fuel conversion efficiency. The analysis provided insights into flame morphology, propagation speed, and distortion under varying conditions, shedding light on the influence of fuel composition and air dilution. Overall, the results contribute to advancing the understanding of syngas combustion behavior in SI engines and hold implications for optimizing engine performance and developing numerical models.
Citation: Gases
PubDate: 2024-05-15
DOI: 10.3390/gases4020006
Issue No: Vol. 4, No. 2 (2024)
- Gases, Vol. 4, Pages 117-132: Carbon Dioxide Capture under Low-Pressure
Low-Temperature Conditions Using Shaped Recycled Fly Ash Particles
Authors: Sherif Fakher, Abdelaziz Khlaifat, Abdullah Hassanien
First page: 117
Abstract: Carbon-capture technologies are extremely abundant, yet they have not been applied extensively worldwide due to their high cost and technological complexities. This research studies the ability of polymerized fly ash to capture carbon dioxide (CO2) under low-pressure and low-temperature conditions via physical adsorption. The research also studies the ability to desorb CO2 due to the high demand for CO2 in different industries. The adsorption–desorption hysteresis was measured using infrared-sensor detection apparatus. The impact of the CO2 injection rate for adsorption, helium injection rate for desorption, temperature, and fly ash contact surface area on the adsorption–desorption hysteresis was investigated. The results showed that change in the CO2 injection rate had little impact on the variation in the adsorption capacity; for all CO2 rate experiments, the adsorption reached more than 90% of the total available adsorption sites. Increasing the temperature caused the polymerized fly ash to expand, thus increasing the available adsorption sites, thus increasing the overall adsorption volume. At low helium rates, desorption was extremely lengthy which resulted in a delayed hysteresis response. This is not favorable since it has a negative impact on the adsorption–desorption cyclic rate. Based on the results, the polymerized fly ash proved to have a high CO2 capture capability and thus can be applied for carbon-capture applications.
Citation: Gases
PubDate: 2024-05-23
DOI: 10.3390/gases4020007
Issue No: Vol. 4, No. 2 (2024)
- Gases, Vol. 4, Pages 1-17: Natural Gas Matters: LNG and India’s
Quest for Clean Energy
Authors: Subhadip Ghosh, Rajarshi Majumder, Bidisha Chatterjee
First page: 1
Abstract: India, the world’s most populous country, is the world’s third-largest emitter of greenhouse gases (GHGs). Despite employing several energy sources, it still relies heavily on coal, its primary energy source. Given India’s swiftly rising energy demand, this challenges meeting emission reduction targets. In recent years, India has significantly increased investments in renewables like solar and hydrogen. While commendable, these initiatives alone cannot meet the country’s expanding energy demands. In the short term, India must rely on both domestic and imported fossil fuels, with natural gas being the most environmentally friendly option. In this context, this paper attempts to forecast energy consumption, natural gas production, and consumption in India until 2050, using both univariate and multivariate forecasting methods. For multivariate forecasting, we have assumed two alternative possibilities for GDP growth: the business-as-usual and the high-growth scenarios. Each of our forecasts indicates a notable shortfall in the projected production of natural gas compared to the expected demand, implying our results are robust. Our model predicts that nearly 30–50 percent of India’s natural gas consumption will be met by imports, mainly in the form of LNG. Based on these findings, this paper recommends that Indian government policies emphasize increasing domestic natural gas production, importing LNG, and expanding renewable energy resources.
Citation: Gases
PubDate: 2024-02-03
DOI: 10.3390/gases4010001
Issue No: Vol. 4, No. 1 (2024)
- Gases, Vol. 4, Pages 18-40: A Review on the Process of Greenhouse Gas
Inventory Preparation and Proposed Mitigation Measures for Reducing Carbon
Footprint
Authors: Cevat Yaman
First page: 18
Abstract: Greenhouse gases trap heat in the atmosphere, causing the Earth’s surface temperature to rise. The main greenhouse gases are carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, and sulfur hexafluoride. Human activities are increasing greenhouse gas concentrations rapidly, which is causing global climate change. Global climate change is increasing environmental and public health problems. To reduce greenhouse gas emissions, it is necessary to identify where the emissions are coming from, develop a plan to reduce them, and then implement and monitor the plan to ensure that emissions are actually reduced. Anthropogenic global climate change has large and increasingly adverse economic effects. Cities emit the most greenhouse gas due to fossil fuel burning and power usage. The four major greenhouse gas emitters are energy, transportation, waste management, and urban land use sectors. Organizations should prepare action plans to lower their greenhouse gas emissions and stop the worst consequences of climate change. These action plans require companies and local authorities to submit their greenhouse gas emissions reports on a yearly basis. A greenhouse gas emissions management system includes several processes and tools created by organizations to understand, measure, monitor, report, and validate their greenhouse gas emissions. Two of the most widely adapted frameworks for greenhouse gases inventory reporting are ISO 14064 and the greenhouse gas protocol. This review paper aims to identify some of the key points of GHG inventory preparation and mitigation strategies.
Citation: Gases
PubDate: 2024-03-15
DOI: 10.3390/gases4010002
Issue No: Vol. 4, No. 1 (2024)
