Natural Gas Research Articles

RESULTS OF TREATMENT OF PATIENTS WITH RHEGMATOGENOUS RETINAL DETACHMENT WITH RUPTURE IN THE LOWER HEMISPHERE DEPENDING ON THE SURGICAL METHOD

Purpose: To evalute the efficacy of short-term tamponade of the vitreal cavity by perfluorinated compound and to analyze the morphological changes after surgical treatment of the patients with rhegmatogenous retinal detachment with rupture in the lower retinal hemisphere.Material and methods: The analysis of surgical treatment of 31 patients with the diagnosis of primary rhegmatogenous retinal detachment in combination with proliferative vitreoretinopathy с type 1–2 with inclusion of the macular zone, with the localization of the rupture in the lower retinal hemisphere. All patients were divided into two groups depending on the tamponade vitreous cavity. I group (n = 15): first stage – vitreoretinal surgery with a tamponade of the vitreous cavity of perfluoroorganic compounds for 14 days, second stage – removal of perfluoroorganic compounds from the vitreous cavity + facoemulsification with implantation of the intraocular lens + tamponade of the natural gas mixture (С2F6). Monitoring for at least 6 months after perfluorinated compound or silicone oil removal.Results: The preliminary results of the study showed a high effectiveness of short-term perfluorinated compound tamponade compared to the silicone oil tamponade in patients with rhegmatogenous retinal detachment with rupture in the lower hemisphere. In all 1st group patients complete retinal reattachment was achieved in all observation periods. In 2nd group, partial retinal reattachment in the lower departments in the long-term postoperative period was detected in 37.5% of cases. There was no cystic macular edema in Group 1 patients, while it occurred in Group 2 patients in 18.7%. Epiretinal fibrosis was detected in Group 1 patients in 14.3% of cases and in Group 2 patients in 31.2% of cases during the whole observation period.Conclusion: The results of the conducted study confirm the effectiveness of the use of short-term tamponade of the vitreous cavity of perfluorinated compound in the treatment of patients with retinal detachment at the localization of a tear in the lower retinal hemisphere. This method improves the anatomical results of vitreoretinal surgery in this category of patients and helps to reduce the number of postoperative complications.

Alternative Analyzers for the Measurement of Gaseous Compounds During Type-Approval of Heavy-Duty Vehicles

Emissions standards describe the fuels, the procedures, and, among others, the analyzers to be used for the measurement of the different compounds during the type-approval of heavy-duty engines and vehicles. Traditionally, NOx, CO, hydrocarbons, and CO2 were the gaseous compounds measured within the Euro standard, with the later addition of CH4 and NH3. Euro 7, introduced in early 2024, expanded those compounds, requiring the measurement of N2O and HCHO. With an increasing number of molecules that need to be measured and introducing carbonless fuels, such as hydrogen, that present different requirements compared to carbon-based fuels, the test procedure needs to be updated. The performances of three laboratory-grade instruments and three portable emissions measurement systems based on Fourier-transformed infrared (FTIR) or quantum cascade laser infrared (QCL-IR) technologies were investigated while measuring from the tailpipe of a Diesel engine and a compressed natural gas (CNG) vehicle. All instruments presented good agreement when emissions of NOx, CO, CH4, NH3, N2O, HCHO, and CO2 were compared using: Z-score, F-test and two tail t-test of student. Water concentration measured by the four FTIRs was also in good agreement. Moreover, the dry emissions of CO2 and CO measured by the laboratory non-dispersive infrared (NDIR) and corrected using water were a few percentages different from those obtained using the regulated carbon-based approach. The results indicate that all the investigated systems are suitable for the measurement of the investigated gaseous compounds, including CO2 and H2O.

Policy impact on economic and environmental sustainability of anaerobic digestion: Industrial case study Insights.

This paper thoroughly examines how policy incentives impact the economic and environmental sustainability of anaerobic digestion (AD) systems. It uses techno-economic and life cycle analyses, along with real industry data, to explore the entire AD process-from feedstock acceptance to digestate disposal. It evaluates the effects of various U.S. policy crediting programs on the economic viability of different AD pathways for treating sewage sludge and food waste. Tipping fees are identified as the primary driver of profitability, while policy credits play a crucial role in enhancing economic feasibility, particularly for renewable natural gas production. However, future regulatory changes could reshape this economic landscape. All AD pathways are found to significantly reduce greenhouse gas emissions, though economic outcomes are highly sensitive to digestate disposal costs and feedstock tipping fees. Co-digestion with food waste is proposed as a strategy to reduce dependence on policy credits and improve long-term economic stability.

Temporal Trends in Soil Health and Productivity on Reclaimed Natural Gas Pipeline Rights‐of‐Way on Cropland

ABSTRACTThe construction of underground pipelines negatively impacts soil productivity in various ecosystems. However, the temporal progression in the recovery of soil productivity following the reclamation of cropland impacted by natural gas pipeline rights‐of‐way (ROWs) construction remains unclear. This study examined temporal, post‐reclamation changes in selected soil health indicators and productivity on reclaimed underground natural gas pipeline ROWs on cropland. Soil and crop samples were collected from ROWs ranging in time elapsed since reclamation (TSR) from 6 to 12 years and from adjacent undisturbed locations (off‐ROW) in the same field. The soil samples were analyzed for soil health indicators (permanganate‐oxidizable carbon (POXC), soil respiration, and autoclaved citrate‐extractable (ACE) protein) and selected chemical properties. Crop samples were assessed for grain and total biomass yields as well as grain protein content. Compared to the off‐ROW, soil organic C on the ROWs was 29% (6‐year ROW) and 33% (9‐year ROW) lower than on the off‐ROWs. Soil respiration recovered within 6 years of ROW reclamation, whereas it took 12 years for POXC and ACE protein to recover to off‐ROW levels. Grain and biomass yields 12 years post‐reclamation were still 42% and 36%, respectively, lower on the ROWs than on the off‐ROWs. However, measured soil attributes recovered faster than crop variables, indicating that pipeline construction on cropland has longer‐term impacts on crop yields than on soil attributes. These results indicate that, although underground pipeline construction has detrimental impacts on soil and crop attributes, these attributes would slowly recover to pre‐construction levels with increasing TSR.

Polyethylene Glycol-Protected Zinc Microwall Arrays for Stable Zinc Anodes.

Aqueous zinc-ion batteries promise good commercial application prospects due to their environmental benignity and easy assembly under atmospheric conditions, positioning them as a viable alternative to lithium-ion batteries. However, some inherent issues, such as chaotic zinc dendrite growth and inevitable side reactions, challenge the commercialization progress. In this work, we imprint highly ordered zinc microwall arrays to regulate the electric field toward uniform Zn deposition. Afterward, coating a polyethylene glycol protection layer on the zinc microwalls aims to passivate the surface defects that rise unintentionally by mechanical imprinting. Polyethylene glycol can also boost oriented Zn deposition along the (002) plane and inhibit hydrogen gas production, further enhancing the stability of such three-dimensional (3D) hybrid anodes. Compared to the messy electric field near the polyethylene glycol-protected Zn foil, the uniform electric field provided by these 3D hybrid anodes can regulate the Zn deposition behaviors, enabling a longer lifespan and thus certifying the necessity of adding 3D microstructures. Additionally, 3D microstructures can offer a larger surface area than that of the planar Zn foil, providing more reaction sites and higher specific capacity. In this case, the 3D hybrid electrode exhibits a good initial capacity of approximately 120 mA h/g at a current density of 5 A/g and a nice retention of more than 80% after 800 cycles. The proposed scheme paves the way for a long-term stable 3D zinc anode solution with promising application prospects.

Enhancement of anaerobic digestion by adding elemental sulfur.

In this study, a new approach to enhance methane (CH4) production from organic substrates in anaerobic digestion (AD) has been discovered. That is, the addition of elemental sulfur (S0) particles into the AD system promotes the synergistic growth of elemental sulfur disproportionation bacteria, acidogenic bacteria and methanogenic archaea, thus facilitating hydrolysis, acidogenesis and methanogenesis. The efficacy of this AD enhancement pathway was confirmed in AD experiments with glucose as a model organic substrate. The results demonstrated that CH4 production in the AD system increased considerably with S0 dosages ranging from 20 mg/L to 300 mg/L. Two gas production peaks appeared at dosages of 20 mg/L and 180 mg/L, where the total CH4 production increased by 2.1 times and 2.5 times, respectively compared with the control group. However, inhibitory effect was observed for S0 dosages above 300 mg/L. The chemical states of S, the microbial community and the abundance of key functional enzymes in the AD system were analyzed. The results showed that S0 addition increased the relative abundance of Dethiobacteraceae, Caldatribacterium, Anaerolineaceae, Methanobacterium and Methanosaeta and considerably increased the abundance of key functional enzymes, such as dehydrogenase, D-glucosidic glucosidase, pyruvate synthase and acetyl-CoA deacetylase. The enrichment of these microorganisms and functional enzymes was strongly positively correlated with the production of volatile fatty acids and CH4, demonstrating that S0 addition effectively enhances methanogenesis during AD.

CHARACTERISTICS OF THE DEVELOPMENT OF THE GAS SUPPLY SYSTEM IN THE REPUBLIC OF ARMENIA

Gas distribution and transportation networks make up the gas supply system. Providing natural gas to the public and the economy is the primary objective of the gas delivery system. Every nation's gas supply network is strategically vital since the cost of natural gas directly impacts the goods and services that are produced and rendered there. It is true that developed nations are looking for innovative technology for natural gas extraction because it is a non-renewable resource. Founded during the Soviet era and throughout multiple phases of development, the Republic of Armenia's gas supply system is a component of the worldwide network. The Public Services Regulatory Commission and the Armenian government, through the Ministry of Territorial Administration and Infrastructure, oversee the country's gas supply industry. The article discusses the Republic of Armenia's domestic natural gas market's supply and sales, its background and present state, investment initiatives, and features that increase the system's operational efficiency.

Unit commitment in solar‐based integrated energy distribution systems with electrical, thermal and natural gas flexibilities: Application of information gap decision theory

AbstractThe depleting oil reserves, air pollution and increasing energy demand, have overturned the focus of the scientific community to renewable energy sources. Among which the photovoltaic (PV) systems occupy more than half of the market share and are generally installed at the distribution level. The volatile and uncertain nature of these PV productions necessitates flexible resources in energy systems. To this end, the district heating systems have an outstanding flexibility on account of their high thermal inertia. This study investigates the optimal unit commitment scheduling for gas‐fired and non‐gas‐fired distributed generation units (NGU) in an integrated energy distribution system (IEDS) within the physical constraints of the electrical, natural gas and thermal energy distribution networks. Moreover, a planning‐based optimization framework is proposed to investigate the investment of battery storage systems in the electric distribution network under the high penetration of PV systems with the aim of enhancing flexibility and reducing the operating costs of the IEDS. In this framework, the information gap decision theory is deployed under risk‐averse and risk‐seeker strategies to deal with uncertain PV energy production. Additionally, the environmental emissions are considered in a multi‐objective approach. The IEDS is embodied through IEEE 33‐bus EDS, 20‐node natural gas network and an 8‐node district heating systems. Eventually, The proposed approach makes a noteworthy contribution to the advancement of solar energy systems in IEDS.

Opportunities and Challenges of Fuel Cell Electric Vehicle-to-Grid (V2G) Integration

This paper presents an overview of the status and prospects of fuel cell electric vehicles (FC-EVs) for grid integration. In recent years, renewable energy has been explored on every front to extend the use of fossil fuels. Advanced technologies involving wind and solar energy, electric vehicles, and vehicle-to-everything (V2X) are becoming more popular for grid support. With recent developments in solid oxide fuel cell electric vehicles (SOFC-EVs), a more flexible fuel option than traditional proton-exchange membrane fuel cell electric vehicles (PEMFC-EVs), the potential for vehicle-to-grid (V2G)’s implementation is promising. Specifically, SOFC-EVs can utilize renewable biofuels or natural gas and, thus, they are not limited to pure hydrogen fuel only. This opens the opportunity for V2G’s implementation by using biofuels or readily piped natural gas at home or at charging stations. This review paper will discuss current V2G technologies and, importantly, compare battery electric vehicles (BEVs) to SOFC-EVs for V2G’s implementation and their impacts.

FOSSIL FUEL EMISSION PREDICTION SYSTEM USING MULTIPLE KERNEL GAUSSIAN PROCESS

<p>According to the United States Environmental Protection Agency, 81% of greenhouse gas emission is due to Carbon-dioxide. When fossil fuels, solid waste, trees, and wood products are burnt, Carbon-dioxide emission occurs. The concentration of Carbon-dioxide in the atmosphere is reduced when it is absorbed by plants as a part of the biological carbon cycle. The major sources of CO2 emission are from fossil fuel such as coal, natural gas, oil, cement production, gas flares used in industrial plants and bunker fuels used in ships. Increase in CO2 emission leads to the increase in global warming. Climate change, change in seasonal events and decrease in agricultural productivity are the major impacts of global warming. Hence it is important to study and analyse CO2 emission based on the recorded data across the globe. Further the major source of emission must be detected and alert messages must be sent to the pollution control boards in various countries to take necessary remedial actions. This work focuses on predicting the CO2 emission in the near future in various countries based upon the “Fossil-Fuel CO2 Emissions by Nation” dataset recorded by Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory. This system comprises of data cleaning, data normalization, optimization, and model building. The model built using Multiple Kernel Gaussian Process (MKGP) will predict the concentration of CO2 that may be present in the atmosphere in upcoming years. Based on the prediction the major source of CO2 emission is identified. We have studied the effects of Radial Basis Function kernel, Rational Quadratic, Periodic kernel and combinations of the kernels on India USA and China dataset. We have proposed a Multi-Kernel Gaussian Process for predicting the fossil fuel emission (MKGP - FFE). It has been inferred that combination of kernels performed well when compared to individual kernels in most of the cases.</p>

Changes in the Global Structure of Energy Consumption and the Energy Transition Process

The global energy transition represents a pivotal aspect of the pursuit of sustainable development and the reduction of greenhouse gas emissions. The objective of this study was to examine the dynamic relationships between global primary energy consumption and the consumption of individual energy sources (nuclear, oil, coal, natural gas, renewables) from 2011 to 2023. To examine both long-run and short-run relationships between variables, advanced econometric methods were employed, including the Johansen cointegration test and the Vector Error Correction Model (VECM). Furthermore, an Index of Sustainable Energy Transformation (ISTE) was devised to quantify the advancement of the transition to low-carbon energy sources. The analysis confirms the existence of long-term equilibrium relationships between global primary energy consumption and the consumption of individual energy sources. The analysis revealed that renewable energy consumption exerts a considerable influence on primary energy consumption, both in the short and long term. The ISTE index demonstrated a notable increase over the period of 2011 to 2023, indicative of advancement in the global energy transition. The results confirm the existence of a stable long-term equilibrium between global primary energy consumption and the consumption of individual energy sources. The observed increase in the ISTE index indicates progress towards low-carbon energy sources, which has important implications for energy policy and sustainable development. The results can support policymakers in monitoring the progress of the energy transition and shaping policies to accelerate the development of renewable energy sources.

AN OVERVIEW OF ENERGY CONSUMPTION AND CO2 EMISSIONS IN IRAN'S RESIDENTIAL SECTOR: ENERGY TRANSITION AND SUBSIDY POLICIES

The transition from fossil fuels to renewable energy sources has become a critical global issue, particularly in response to climate change. This study aims to analyse the trends in energy consumption and CO2 emissions within Iran's household sector. The findings reveal a significant increase in energy consumption in Iran between 2001 and 2019. Despite the household sector's heavy reliance on fossil fuels, a shift in fuel consumption patterns can be observed, with a transition from oil to natural gas starting in 2008. Electricity generation in Iran is also predominantly fossil fuel-based, with natural gas playing a major role. This underscores the urgent need to reinforce renewable energy sources to mitigate CO2 emissions from the household sector. Another key factor influencing energy consumption in Iran is the country's extensive energy subsidies. The disparity in fuel prices compared to neighbouring countries has also led to fuel smuggling. However, the results show that the twophase subsidy reform plan implemented in 2010 and 2013 did not lead to a reduction in energy consumption. Therefore, further reforms are needed to improve energy equity and reduce CO2 emissions in the household sector.

Geochemical characteristics and origin of crude oil and natural gas in different areas of Wenchang-A Sag, Pearl River Mouth Basin, South China Sea

Geochemical characteristics and origin of crude oil and natural gas in different areas of Wenchang-A Sag, Pearl River Mouth Basin, South China Sea

Gas Production from Three-Phase Coexisting Sandy Hydrate Systems Induced by Depressurization: Insights into Water- and Gas-Rich Environments

Gas Production from Three-Phase Coexisting Sandy Hydrate Systems Induced by Depressurization: Insights into Water- and Gas-Rich Environments

Predicting Natural Gas Production in Various Nations Using a Fractional Grey Bernoulli Approach

Accurate forecasting of natural gas production is crucial for economic stability, environmental sustainability, and market investment. This study presents an advanced forecasting method using the fractional grey Bernoulli model, which combines fractional accumulation and Bernoulli processes to enhance the predictive accuracy for nonlinear datasets. The model’s versatility and flexibility allow it to adapt to various data characteristics and complexities, thereby outperforming traditional grey models in forecasting performance. To optimize the model parameters, this study employs the Particle Swarm Optimization (PSO) algorithm, further improving the model’s effectiveness. Empirical analysis of natural gas production data from Brazil, Italy, and Qatar demonstrates that the model exhibits significant advantages in both fitting and forecasting capabilities. The findings indicate that the fractional grey Bernoulli model achieves high accuracy and reliability in predicting natural gas production in these countries, providing a robust framework for strategic energy planning and investment decision-making. With average forecast errors of 1.9113%, 4.0353%, and 1.8902% for natural gas production in Brazil, Italy, and Qatar respectively, this study underscores the model’s effectiveness in enhancing forecast reliability and minimizing risk, providing valuable insights for sustainable energy development.

Comparative Study of Different Alternative Fuel Options for Shipowners Based on Carbon Intensity Index Model Under the Background of Green Shipping Development

The International Maritime Organization (IMO)’s annual operational carbon intensity index (CII) rating requires that from 1 January 2023, all applicable ships meet both technical and operational energy efficiency requirements. In this paper, we conduct a comparative study of different alternative fuel options based on a CII model from the perspective of shipowners. The advantages and disadvantages of alternative fuel options, such as liquefied natural gas (LNG), methanol, ammonia, and hydrogen, are presented. A numerical example using data from three China Ocean Shipping (Group) shipping lines is analyzed. It was found that the overall attained CII of different ship types showed a decreasing trend with the increase of the ship’s deadweight tonnage. A larger ship size choice can obtain better carbon emission reduction for the carbon emission reduction investment program using alternative fuels. The recommended options of using LNG fuel and zero-carbon fuel (ammonia and hydrogen) on Route 1 and Route 3 during the study period were analyzed for the shipowners. Carbon reduction scenarios using low-carbon fuels (LNG and methanol) and zero-carbon fuels (ammonia and hydrogen) on Route 2 are in line with IMO requirements for CII.

Seasonality, sources apportionment, human health risks assessments, and potential implications on the atmospheric chemistry of polycyclic aromatic hydrocarbons in size-segregated aerosols from a Romanian metropolitan area.

Urbanization and industrialization are important transformations shaping the current statement of the society, enhancing significantly the combustion emissions which are threatening the global climate system, air quality, and human health. These emissions contain polycyclic aromatic hydrocarbons (PAHs) which are well known for their high toxicity. The present study is the first assessing the seasonal variation of 17 PAHs in size segregated fractions of atmospheric aerosol particles from a Romanian metropolitan area. In addition to sources apportionment and health risks, the potential role of PAHs on the atmospheric chemistry in the area was also addressed. Higher PAHs concentrations were determined in winter season, the highest values being quantified for benzo[b]fluoranthene, benzo[a]pyrene, and indeno[1,2,3-cd]pyrene. Each analyzed PAH exhibited a dominant peak in the accumulation mode (0.1-1.0 μm), with maxima at 381 nm. Gasoline combustion was identified as a significant contributor to the PAHs levels in the atmospheric aerosols from the area. Biomass-burning contributions were highlighted during the winter and autumn seasons. The positive matrix factorization (PMF) model apportioned four PAHs sources, as follows: vehicular (31%), mixed combustion (33%), biomass and wood burning (19%), and coal and natural gas combustion (18%) sources. Concentration-weighted trajectory (CWT) analysis method revealed clear contributions to PAHs abundances from local and regional air masses. Alveolar region of adults seems to have the highest susceptibility for PAHs deposition. Values exceeding acceptable limits for carcinogenic risk throughout the year are associated with benzo[a]pyrene, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, benzo[a]anthracene etc. The present study can be considered as a reference in the region in order measures of mitigation and control for PAHs emission sources to be introduced.

Optimizing energy consumption in post-combustion CO2 capture at an NGCC power plant: a simulation-based approach

Abstract This study aims to optimize energy consumption in post-combustion carbon capture processes at a Natural Gas Combined Cycle (NGCC) power plant. It further addresses challenges associated with steam extraction from NGCC power plants and explores non-condensable steam turbines to boost process efficiency. Various scenarios are explored to minimize energy requirements by leveraging heat integration and alternative solvent compositions. The research uses simulations with commercially available software and literature-derived data to address the challenges of high energy consumption in such processes. Emphasis is placed on optimizing solvent composition and implementing advanced heat optimization strategies to reduce energy consumption. Four scenarios with different solvent compositions are investigated, utilizing Monoethanolamine and aqueous piperazine. The results show that process parameter optimization and heat optimization strategies can result in significant energy savings. To attain a carbon-neutral energy landscape, this research helps develop more sustainable and effective carbon capture methods.

Iron Oxide Clusters as Electron Donors Under Light Enhance Oxygen Reduction Kinetics at Atomically Dispersed Fe for Photocatalytic CH4 Partial Oxidation

AbstractPhotocatalytic CH4 oxidation to CH3OH emerges as a promising strategy to sustainably utilize natural gas and mitigate the greenhouse effect. However, there remains a significant challenge for the synthesis of methanol by using O2 at low temperature. Inspired by the catalytic structure in soluble methane monooxygenase (MMO) and the corresponding reaction mechanism, we prepared a biomimetic photocatalyst with the decoration of Fe2O3 nanoclusters and satellite Fe single atoms immobilized on carbon nitride. The catalyst demonstrates an excellent CH3OH productivity of 5.02 mmol ⋅ gcat−1 ⋅ h−1 with CH3OH selectivity of 98.5 %. Mechanism studies reveal that the synergy between Fe2O3 nanoclusters and Fe single atoms establishes a dual‐Fe site as MMO for O2 activation and subsequent CH4 partial oxidation. Moreover, the light excitation of Fe2O3 nanoclusters with a relative narrow band gap could deliver the electrons and protons to atomic Fe that facilitating the oxygen reduction kinetics for the robust of CH3OH synthesis.

Carbon dioxide capture in large-scale CCGT power plant from flue gases obtained from various fuel mixtures

In this study, the thermodynamic analysis of a combined cycle gas turbine integrated with post-combustion carbon capture and storage using the solvent method is performed. The syngas obtained from the gasification of sewage sludge is mixed with methane and nitrogen-rich natural gas fuels at different proportions, used in the gas turbine, and the properties of fuel and flue gases are analyzed. The flue gas obtained from the fuel mixture is passed through the post-combustion carbon capture and storage at various load conditions to assess the heat and electricity required for the carbon capture process. The solvent used for the carbon capture from flue gases enables CO2 capture with the high efficiency of 90%. With the calculated results, the load conditions of flue gas using fuel mixtures are identified, which reduces the heat and power demand of post-combustion carbon capture and storage and provides the possibility to achieve neutral emission. The impact of selected operating conditions of post-combustion carbon capture and storage on the CO2 emission reduction process and on the power plant performances is investigated. Considering the factors of electricity generation, energy efficiency, heat supply to the consumers, operating load of post-combustion carbon cap-ture and storage and CO2 emission, the 50% mixture of syngas with both fuels performs better. Also, the use of a mixture of 2-amino-2methyl-1-propanol and piperazine with reboiler duty 3.7 MJ/kgCO2 in post-combustion carbon capture and storage slightly enhanced the performance of the power plant compared to the use of monoethanolamine with reboiler duty 3.8 MJ/kgCO2.