Methane Utilization Research Articles

Управление производственным риском, обусловленным взаимодействием угледобывающих и сервисных предприятий

Outsourcing of service and ancillary work, as a way to increase production productivity while reducing costs, is increasingly used in coal companies. At the same time, a significant proportion of industrial injuries at service and auxiliary enterprises is formed due to the lack of clear regulations for their interaction with mining enterprises. Therefore, the problem of interaction between service and coal mining enterprises of a coal company is considered in the aspect of production risk management. The analysis showed that the legal documents of coal mining enterprises do not contain requirements for the formation and provision of safe working conditions and briefings for third-party workers, and there are no clear boundaries for the responsibility of the parties in case of incidences. The main difficulty in creating safe working conditions for the employees of service enterprises is as follows: it is not defined who exactly, the contractor or the customer, should allocate resources to ensure safe working conditions; the work on ensuring the safety of employees of contracting organizations by the heads of the main enterprises often does not fall into the zone of their attention, since they are busy with their own production problems and tasks. To eliminate these shortcomings, it is advisable to form a unified mechanism for managing production risk for the main and contracting enterprises, which should include measures to create safe working conditions for contractors. The basis of this mechanism should be the control of hazardous production situations. At the same time, situations that arise at the junction of the responsibility of contracting organizations and customer enterprises should be singled out in a separate group - joint operations. The article presents the results of the implementation of the proposed mechanism obtained in the course of the joint work of coal mining enterprises with the Department of Degassing and Utilization of Methane, and the enterprise PE «Spetsnaladka» operating in the underground conditions at the mines of the association AO «SUEK-Kuzbass».

Prospecting the significance of methane-utilizing bacteria in agriculture.

Microorganisms act as both the source and sink of methane, a potent greenhouse gas, thus making a significant contribution to the environment as an important driver of climate change. The rhizosphere and phyllosphere of plants growing in natural (mangroves) and artificial wetlands (flooded agricultural ecosystems) harbor methane-utilizing bacteria that oxidize methane at the source and reduce its net flux. For several decades, microorganisms have been used as biofertilizers to promote plant growth. However, now their role in reducing net methane flux, especially from flooded agricultural ecosystems is gaining momentum globally. Research in this context has mainly focused on taxonomic aspects related to methanotrophy among diverse bacterial genera, and environmental factors that govern methane utilization in natural and artificial wetland ecosystems. In the last few decades, concerted efforts have been made to develop multifunctional microbial inoculants that can oxidize methane and alleviate greenhouse gas emissions, as well as promote plant growth. In this context, combinations of taxonomic groups commonly found in rice paddies and those used as biofertilizers are being explored. This review deals with methanotrophy among diverse bacterial domains, factors influencing methane-utilizing ability, and explores the potential of novel methane-utilizing microbial consortia with plant growth-promoting traits in flooded ecosystems.

An energy storage approach for storing surplus power into hydrogen in a cogeneration system

Hydrogen, as a future energy carrier, can be used for grid power peak shaving and valley filling and has thus attracted widespread attention. However, the most urgent challenge that needs to be overcome is determining an effective method for providing high-temperature heat for water electrolysis. This study proposes a new approach for driving hydrogen production by adopting high-temperature combustion heat from the cogeneration system. Its feasibility and energy conversion performance are investigated. The results show that the power-/heat-to-hydrogen efficiency can reach approximately 0.95. Meanwhile, when hydrogen is continuously produced, the input work of the compressor and the output work of the turbine are always maintained at 245.4 kW and 448.0 kW, respectively. Namely, the thermodynamic parameters of the gas turbine remain unaffected while storing surplus power into hydrogen. In addition, the relative fluctuations of the cooling and heating outputs and component efficiency are controlled within 0.1 and 0.007, respectively. Importantly, the new approach can achieve the cascade utilization of methane, realizing the improvement of low-grade heat. For example, the energy level of solar heat of 650 °C and latent heat of 100 °C could be enhanced from 0.68 to 0.76 and 0.20 to 0.83, respectively. As a result, a higher thermodynamic degree of perfection of the thermodynamic system is obtained. Finally, the results of this study would be applied to store intermittent renewable electricity efficiently in the future.

Highly Selective Carbonylation of CH3Cl to Acetic Acid Catalyzed by Pyridine‐Treated MOR Zeolite

AbstractThe selective conversion of methane to high value‐added chemicals under mild conditions is of great significance for the commercially viable and sustainable utilization of methane but remains a formidable challenge. Herein, we report a strategy for efficiently converting methane to acetic acid via CH3Cl as an intermediate. Up to 99.3 % acetic acid and methyl acetate (AA+MA) selectivity was achieved over pyridine‐pretreated MOR (MOR‐8) under moderate conditions of 523 K and 2.0 MPa. Water, conventionally detrimental to carbonylation reaction over zeolite catalysts, was conducive to the production of AA in the current reaction system. In the 100 h continuous test with the MOR‐8 catalyst, the average AA+MA selectivity remained over 98 %. AA was formed by carbonylation of methoxy groups within 8‐membered rings of MOR followed by hydrolysis. This strategy provided an approach for highly efficient utilization of methane to oxygenates under mild reaction conditions.

Highly Selective Carbonylation of CH3 Cl to Acetic Acid Catalyzed by Pyridine-Treated MOR Zeolite.

The selective conversion of methane to high value-added chemicals under mild conditions is of great significance for the commercially viable and sustainable utilization of methane but remains a formidable challenge. Herein, we report a strategy for efficiently converting methane to acetic acid via CH3 Cl as an intermediate. Up to 99.3 % acetic acid and methyl acetate (AA+MA) selectivity was achieved over pyridine-pretreated MOR (MOR-8) under moderate conditions of 523 K and 2.0 MPa. Water, conventionally detrimental to carbonylation reaction over zeolite catalysts, was conducive to the production of AA in the current reaction system. In the 100 h continuous test with the MOR-8 catalyst, the average AA+MA selectivity remained over 98 %. AA was formed by carbonylation of methoxy groups within 8-membered rings of MOR followed by hydrolysis. This strategy provided an approach for highly efficient utilization of methane to oxygenates under mild reaction conditions.

Experimental investigation of the high temperature chlorination of methane in a tubular reactor

High temperature methane chlorination offers an alternative process route to the utilization of methane, since the presence of chlorine lowers the pyrolysis temperature. Chlorine, methane and nitrogen were introduced in a tubular reactor while varying hydrogen to chlorine ratios at temperatures ranging from 600 °C to 1000 °C. The chlorine conversion rates, hydrogen chloride yields, and the chlorine content in the soot were determined. While complete conversion of the limiting reactant was found in most experiments, differing trends were observed for the hydrogen chloride yield. Chlorine was almost always found in the carbon. At the same methane flow rate, a tendency for carbon formation was ascertained to depend on the amount of chlorine supplied, with the most extensive deposits being formed for a hydrogen to chlorine ratio of unity. Furthermore, in the case of high chlorine excess, crystalline products form at the reactor outlet.

How to Plan for Methane Mitigation and Utilisation Strategies?

How to Plan for Methane Mitigation and Utilisation Strategies?

Process hazard considerations for utilization of renewable methane from biogas

AbstractBiogas production and use is a growing sector in the global alternative energy landscape. Biogas is a mixture of carbon dioxide and hydrocarbons (primarily methane) that is generated from the biological breakdown of organic material. This mixture can be separated and upgraded to produce renewable methane with a lower greenhouse gas footprint and cumulative energy demand than natural gas generated from fossil fuels. Biogas generation also typically provides an additional benefit of utilizing a waste stream as a feedstock. As industries and economies continue to produce organic waste, biogas and biomethane generation represent a large opportunity for production of sustainable fuels that can be used as drop‐in replacements for common fossil fuels. As a result, biogas generation and production of renewable methane are attractive technologies for industries with an aim to reduce their impact on the environment and meet sustainability goals. However, the production of biogas presents its own set of hazards and challenges that must be identified, analyzed, and mitigated. The paper will address common hazards (and how to manage the hazards) that a facility encounters when developing a project aimed at utilizing renewable methane through biogas generation.

Co-Production System Based on Lean Methane and Biogas for Power Generation in Coal Mines

The problem of low efficiency of coal mine methane utilization is caused by the concentration of methane of less than 10%, or a concentration that varies dramatically directly emitted into the atmosphere. This work deals with the concept of a co-production system that blends lean methane and biogas to produce electric energy. It is recommended to add the biogas generated by straws around the mines in a controlled manner to the lean methane flow to obtain the desired gas concentration in order to generate electricity. Potential electricity generation and reduced greenhouse gas emissions were also evaluated. The result shows that the co-production system can significantly improve the utilization efficiency of lean methane in coal mines; the average use of pure methane in three coal mines is 0.18, 1.12, and 5.32 million m3 every year, respectively, and the emission reduction effect of carbon dioxide (CO2) equivalent is, respectively, 3081, 18,796, and 89,050 tons. The electricity generated and the economic environmental benefits of the co-production system are remarkable, and it has economic feasibility and broad perspectives for popularization. It not only has the advantage of improving the utilization rate of methane and biomass and providing power supply and heat source for mines, but also has practical significance in terms of saving energy, reducing environmental pollution, adjusting the energy structure, and achieving the target of carbon emission peak and carbon neutrality.

Investigation of microbial metabolisms in an extremely high pH marine-like terrestrial serpentinizing system: Ney Springs

Ney Springs, a continental serpentinizing spring in northern California, has an exceptionally high reported pH (12.4) for a naturally occurring water source. With high conductivity fluids, it is geochemically more akin to marine serpentinizing systems than other terrestrial locations. Our geochemical analyses also revealed high sulfide concentrations (544 mg/L) and methane emissions (83% volume gas content) relative to other serpentinizing systems. Thermodynamic calculations were used to investigate the potential for substrates resulting from serpentinization to fuel microbial life, and were found to support the energetic feasibility of sulfate reduction, anaerobic methane oxidation, denitrification, and anaerobic sulfide oxidation within this system. Assessment of the microbial community via 16S rRNA taxonomic gene surveys and metagenome sequencing revealed a community composition dominated by poorly characterized members of the Izemoplasmatales and Clostridiales. The genomes of these dominant taxa point to a fermentative lifestyle, though other highly complete (>90%) metagenome assembled genomes support the potential for organisms to perform sulfate reduction, sulfur disproportionation and/or sulfur oxidation (aerobic and anaerobic). Two chemolithoheterotrophs identified in the metagenome, a Halomonas sp. and a Rhodobacteraceae sp., were isolated and shown to oxidize thiosulfate and were capable of growth in conditions up to pH 12.4. Despite being characteristic products of serpentinization reactions, little evidence was seen for hydrogen and methane utilization in the Ney Springs microbial community. Hydrogen is not highly abundant and could be consumed prior to reaching the spring community. Other metabolic strategies may be outcompeted by more energetically favorable heterotrophic or fermentation reactions, or even inhibited by other compounds in the spring such as ammonia. The unique geochemistry of Ney Springs provides an opportunity to study how local geology interacts with serpentinized fluids, while its microbial community can better inform us of the metabolic strategies employed in hyperalkaline environments.

Photocatalytic dry reforming of methane by rhodium supported monoclinic TiO2-B nanobelts

The conversion of methane and carbon dioxide into syngas (dry reforming of methane; DRM) has attracted attention owing to the potential to reuse greenhouse gases. Titanium dioxide (TiO2)-based photocatalysts, which have been widely commercialized owing to their high efficiency, non-toxicity, and low cost, are strongly desired in DRM. Here, we report a monoclinic-phase TiO2-B nanobelts-supported rhodium (Rh/TiO2-B nanobelts) catalyst that efficiently promotes DRM under ultraviolet light irradiation at low temperatures. Photogenerated holes in the TiO2-B nanobelts were used to oxidize methane, while the electrons were trapped in rhodium to reduce carbon dioxide. Rh/TiO2-B nanobelts exhibited considerably higher durability and activity than Rh-loaded conventional TiO2 (anatase and rutile), owing to the lattice and/or surface oxygen reactivity in TiO2-B nanobelts, which was suggested by X-ray photoelectron spectroscopy measurements and photocatalytic performance tests under an atmosphere of methane alone. This study paves the path for the effective utilization of methane by constructing active TiO2-based nanometal photocatalysts.

Poly(3-hydroxybutyrate) production from methane in bubble column bioreactors: Process simulation and design optimization

The pressing problem posed by plastic pollution has led to other, environmentally friendly alternatives, such as polyhydroxyalkanoates. This work proposes an innovative process to produce poly(3-hydroxybutyrate) by replacing expensive substrates, such as sugars, with methane. A two-step process was simulated: a first fermentation is performed in a continuous mode for 20 days to grow a strain belonging to the genus Methylocystis, while a second semi-continuous and nitrogen-limited fermentation is employed to induce the poly(3-hydroxybutyrate) accumulation within 12 days. The effects of the superficial gas velocity on the mass transfer and the poly(3-hydroxybutyrate) production yields were evaluated. Several scenarios were analyzed to optimize the geometry of the reactors and the methane utilization. The working volume of the reactors, as well as the presence of gas recycling stream, were shown to affect the global yields positively, while improving the aspect ratio from 8 to 19, with equal volume, lowered the fraction of poly(3-hydroxybutyrate) into the biomass by up to 37.5%.

Integrative Genome-Scale Metabolic Modeling Reveals Versatile Metabolic Strategies for Methane Utilization in Methylomicrobium album BG8.

ABSTRACTMethylomicrobium album BG8 is an aerobic methanotrophic bacterium with promising features as a microbial cell factory for the conversion of methane to value-added chemicals. However, the lack of a genome-scale metabolic model (GEM) of M. album BG8 has hindered the development of systems biology and metabolic engineering of this methanotroph. To fill this gap, a high-quality GEM was constructed to facilitate a system-level understanding of the biochemistry of M. album BG8. Flux balance analysis, constrained with time-series data derived from experiments with various levels of methane, oxygen, and biomass, was used to investigate the metabolic states that promote the production of biomass and the excretion of carbon dioxide, formate, and acetate. The experimental and modeling results indicated that M. album BG8 requires a ratio of ∼1.5:1 between the oxygen- and methane-specific uptake rates for optimal growth. Integrative modeling revealed that at ratios of >2:1 oxygen-to-methane uptake flux, carbon dioxide and formate were the preferred excreted compounds, while at ratios of <1.5:1 acetate accounted for a larger fraction of the total excreted flux. Our results showed a coupling between biomass production and the excretion of carbon dioxide that was linked to the ratio between the oxygen- and methane-specific uptake rates. In contrast, acetate excretion was experimentally detected during exponential growth only when the initial biomass concentration was increased. A relatively lower growth rate was also observed when acetate was produced in the exponential phase, suggesting a trade-off between biomass and acetate production.IMPORTANCE A genome-scale metabolic model (GEM) is an integrative platform that enables the incorporation of a wide range of experimental data. It is used to reveal system-level metabolism and, thus, clarify the link between the genotype and phenotype. The lack of a GEM for Methylomicrobium album BG8, an aerobic methane-oxidizing bacterium, has hindered its use in environmental and industrial biotechnology applications. The diverse metabolic states indicated by the GEM developed in this study demonstrate the versatility in the methane metabolic processes used by this strain. The integrative GEM presented here will aid the implementation of the design-build-test-learn paradigm in the metabolic engineering of M. album BG8. This advance will facilitate the development of a robust methane bioconversion platform and help to mitigate methane emissions from environmental systems.

Enhanced conversion efficiency and coking resistance of solid oxide fuel cells with vertical-microchannel anode fueled in CO2 assisted low-concentration coal-bed methane

Clean and efficient utilization of the abundant low concentration coal-bed methane (LC-CBM) via solid oxide fuel cells (SOFCs) is highly attractive for saving energy and mitigate the emission of greenhouse gases. However, it still remains a great challenge because of the low conversion efficiency and carbon deposition. Herein, an improvement strategy is proposed via incorporating dry reforming reaction of CO2 assisted LC-CBM. By introducing CO2 in LC-CBM, the methane conversion improves significantly. A maximum methane conversion is achieved by incorporating 5 %CO2 and the value is increased from 31.69% to 50.03%. Meanwhile, a high CO2 conversion of 74.58% is also achieved. The maximum power density of the single cell with vertical-microchannel anode fueled with 5 %CO2 in LC-CBM is 1321.5 mW cm−2 at 800 °C, which is a bit lower than that without CO2 participation. This is probably ascribed to the open circuit voltage decrease caused by the increased partial pressure of oxygen at anode. The coking tolerance of the single cell with CO2 participation can be improved owing to the high conversion efficiency, leading to a stable power output performance. CO2 assisted LC-CBM for SOFCs provides a potential solution for the efficient conversion of the low calorific value fuels.

From layered structure to 8-fold interpenetrated MOF with enhanced selective adsorption of C2H2/CH4 and CO2/CH4

Nature gas plays an important part in daily life and petrochemical industry, but it always coexists with impurities of considerable amount, which hinders full utilization of methane and thus makes its purification an urgent issue to be addressed. Herein, via solvothermal reaction of N,N′-bis(3-methylbenzoic acid-4-yl)-1,4,5,8-naphthalenetetracarboxydiimide (H2L) and cadmium cation, we obtained a layer structure of [Cd2(L)2(H2O)2]·4H2O (UPC-71) with sql/Shubnikov tetragonal plane net topology, where tiny pores are formed due to direct dense packing of layer by layer. After adding 1, 2-bis(4-pyridyl) ethane (BPEA) as ancillary ligand, a rare 8-fold interpenetrated framework, [Cd(L)(BPEA)]·4H2O (UPC-72), was obtained. Limited by their tiny pore volume, UPC-71 and UPC-72 both display somewhat small gas sorption capacities, but an obvious increase in the adsorption/separation performance can be observed in UPC-72 due to the effect of pore confinement strategy. In particular, the quantities of C2H2 and CO2 adsorbed are 1.54 and 0.83 ​mmol/g at ambient condition, and the IAST selectivities of C2H2/CH4 and CO2/CH4 are up to 20.1 and 4.7 for UPC-72. With the aid of GCMC simulation, we prove that there exist stronger binding interactions between C2H2 and CO2 with the active sites in UPC-72, and thus enhances the separation selectivity.

ЭКОНОМИЧЕСКАЯ ЭФФЕКТИВНОСТЬ ЗАБЛАГОВРЕМЕННОГО ИЗВЛЕЧЕНИЯ МЕТАНА ИЗ УГОЛЬНЫХ ПЛАСТОВ В СОВРЕМЕННЫХ УСЛОВИЯХ

One of the key problems of the coal industry in the modern world is the effective degassing and elimination of methane and other gaseous impurities from the developed seams. A high concentration of methane has a negative impact not only on the performance of the mine, but in case of significant excesses, it can lead to a stop in production. Coal mining companies are losing significant financial resources to restore the working capacity of mines and utilize gas impurities, meanwhile, more and more experts are turning to early degassing, which allows you to get rid of most of the natural gas even before the field is put into operation. The purpose of this work is to identify and analyze modern tools for early degassing of coal mines in Russia, taking into account sanctions restrictions on the import of foreign equipment, as well as economic instability in the international energy market. Utilization of methane with early degassing is possible not only by “standard” methods of emission into the atmosphere and flaring, but also by direct use both in the production itself in the generation of heat and electricity, and with subsequent transportation to the end consumer. This method increases economic efficiency and allows to provide power supply to the developed field without connection to the central networks. Also, early degassing has a positive effect on safety and reduces the risk of accidents involving people. The scientific basis of this study was Russian and foreign opinions and assessments of industry experts, statistical data of companies in the fuel and energy complex of Russia, information on patents and import substitution of foreign equipment in the coal industry, federal and regional regulatory databases.

Exploring Win-Wins from Trade-Offs? Co-Benefits of Coalbed Methane Utilization for the Environment, Economy and Safety

With policy incentives for the coalbed methane in energy industry, coalbed methane from coal production has been effectively improved by technology innovations in coalbed methane extraction and utilization. The progress of coalbed methane promotes the clean construction of energy system and contributes to carbon neutrality target. To quantitatively measure the contributions of the coalbed methane in energy industry, this paper builds a carbon emissions accounting system for coalbed methane in China and assesses the historical co-benefits of coalbed methane utilization from the aspects of emissions reduction, safety and economy. By using the parameters of gas content, raw coal production, gas extraction rate and utilization rate over the years, emissions reduction potential and economic viability of coal seam gas are estimated and the safety benefits of coal mine gas extraction are analyzed by using data for gas accidents and economic losses. The results reveal that with the increase in raw coal production, the great emission reduction potential of coalbed methane is expected to benefit clean energy system and the development of carbon neutrality by means of policy incentives and technology innovations. The co-benefit evaluation indicates the huge profitability of coalbed methane from 2012 to 2015 and the significance of emissions reduction and safety gain internalization. Safety benefits are obvious in the negative exponential function between the annual drainage quantities of coalbed methane and annual death tolls from coal mine gas accidents. Based on these results, relevant suggestions are put forward for sustainable development of the coalbed methane in energy industry.

Coal Mine Methane Emissions and Utilization Potential for the Zonguldak Coal Basin, Turkey

Coal Mine Methane Emissions and Utilization Potential for the Zonguldak Coal Basin, Turkey

Coal Mine Methane Emissions and Utilization Potential for the Zonguldak Coal Basin, Turkey

Coal Mine Methane Emissions and Utilization Potential for the Zonguldak Coal Basin, Turkey

Некондиційні горючі копалини України та засади їхньої екологічної конверсії

In the general case, substandard combustible minerals include on-balance and off-balance reserves of primary energy materials - coal and peat deposits (solid combustible minerals) and oil and natural gas deposits (liquid and gaseous combustible minerals), which by physico-chemical, energy or geological-spatial conditions do not meet the economic criteria for extraction and use of traditional technological methods, as well as the potential of methane from coal deposits, arrays of man-made carbon-containing materials such as waste from coal mining, coal beneficiation, refining, etc. Review of the available reserves in terms of the use of modern technologies of environmentally friendly conversion can significantly expand the opportunities for the development of all types of combustible minerals in Ukraine. The paper considers the geological zoning of oil and gas fields and deposits of solid combustible minerals, as well as their reserves and production. It is shown that the reserves of the main primary energy resources in Ukraine many times exceeds the extraction and has significant opportunities to increase due to the use of substandard combustible minerals. The principles of ecologically safe conversion of substandard combustible minerals in terrestrial and underground conditions are presented. The importance of energy utilization of methane from coal deposits, arrays of such man-made carbon-containing materials as coal mining waste, coal beneficiation, oil refining, etc. was noted. The main mining-geological and technological criteria that contribute to the development of coal seams by underground gasification are given, as well as deposits and areas of coal basins of Ukraine that are suitable for underground gasification.