Methane Carbon Dioxide Research Articles

Calorimetric Assessment of Ternary Methane–Carbon Dioxide–Tetrahydrofuran (CH4–CO2–THF) Hydrates: Application in Storage and Transport of CO2 Lean Natural Gas

Calorimetric Assessment of Ternary Methane–Carbon Dioxide–Tetrahydrofuran (CH₄–CO₂–THF) Hydrates: Application in Storage and Transport of CO₂ Lean Natural Gas

Plasma-Induced Catalyst Support Defects for the Photothermal Methanation of Carbon Dioxide.

The presence of defects in a catalyst support is known to benefit catalytic activity. In this work, a He-plasma treatment-based strategy for introducing and stabilising defects on a Ni/TiO2 catalyst for photothermal CO2 hydrogenation was established. The impact of pretreatment step sequence—which comprised He-plasma treatment and reduction/passivation—on defect generation and stabilisation within the support was evaluated. Characterisation of the Ni/TiO2 catalysts indicated that defects created in the TiO2 support during the initial plasma treatment stage were then stabilised by the reduction/passivation process, (P-R)Ni/TiO2. Conversely, performing reduction/passivation first, (R-P)Ni/TiO2, invoked a resistance to subsequent defect formation upon plasma treatment and consequently, poorer photothermal catalytic activity. The plasma treatment altered the metal-support interaction and ease of catalyst reduction. Under photothermal conditions, (P-R)Ni/TiO2 reached the highest methane production in 75 min, while (R-P)Ni/TiO2 required 165 min. Decoupling the impacts of light and heat indicated thermal dominance of the reaction with CO2 conversion observed from 200 °C onwards. Methane was the primary product with carbon monoxide detected at 350 °C (~2%) and 400 °C (~5%). Overall, the findings demonstrate the importance of pretreatment step sequence when utilising plasma treatment to generate active defect sites in a catalyst support.

Load-flexible fixed-bed reactors by multi-period design optimization

Many research activities focus on load-flexible fixed-bed reactors in the context of Power-to-X concepts. One of the main issues is the occurrence of hazardous temperature excursions in steady state and during dynamic load changes. The dilution of the catalytically active fixed-bed with inert particles and the use of catalyst particles with active core and inert shell (so-called core–shell catalyst particles) are proven means to prevent insufficient thermal management. This work aims at comparing both concepts with respect to the reactor’s load-flexibility, exemplified for carbon dioxide methanation. In extension to our previous work of Zimmermann et al. (2020), a multi-period design optimization approach is performed for both concepts, considering one, two, and infinitely many axial fixed-bed segments. This approach simultaneously determines the optimal reactor design and operating parameters, which is inevitable for a sound technological comparison of the two concepts. Additionally, step responses are simulated as worst-case load change policy to switch from one optimized steady state to another. The results show that with core–shell particles shorter tubes can be used than with diluted fixed-beds, if one or two fixed-bed segments are considered. This results in lower pressure loss and higher space–time yield. Additionally, faster load changes can be realized with core–shell catalyst particles. In the case of infinitely many axial fixed-bed segments, both concepts converge to similar space–time yields, but show excessive temperature excursion during load changes.

Determination of natural gas content of coal

The main provisions of the laboratory work are as follows. Purpose - to determine the gas content of coal, which characterizes the actual gas content in coal, and is also the main parameter for predicting gas release into existing mine workings. The gas content is determined in laboratory conditions, and the gas pressure can be determined indirectly on the basis of sorption isotherms, which are characteristic of the corresponding different types of coal. Terms and Definitions. Gas bearing capacity, gas content is the volume of gas contained in the mass [m3/t] of coal. Depending on the composition of the gas, the gas content can be divided, for example, into methane content and carbon dioxide content. Since methane is the main constituent of gas in most cases, the term “gas content” is usually used to mean “methane content”. The value of gas content is usually taken in normal conditions (273 K and 1013.25 hPa).

Experimental investigation on the possibility of defining the feasibility of CO2/CH4 exchange into a natural gas hydrate marine reservoir via fast analysis of sediment properties

The present work deals with an experimental investigation on methane hydrate and carbon dioxide hydrate formation in presence of two different types of sand, which acted as seabed simulators. The first typology of sand consists in pure quartz and is commonly used for laboratory experiments on gas hydrate. The other type is named TS-2 and originated from the Tunisian seabed of the Mediterranean Sea. It is silica-based (≈99%), however it also contains other elements and its grains have different shape, size and porosity. Experiments were carried out in order to verify if the specific characteristic of the seabed, in which the hydrate reservoir is present, may intervene or not on the CO2/CH4 replacement process and if such contribution may improve or reduce the process efficiency. Results proved that physical and chemical properties of materials which composed the seabed, may strongly intervene on the replacement process. In particular, experiments revealed that sand TS-2 acted as kinetic and thermodynamic inhibitor for methane hydrate formation, while it promoted CO2 hydrate formation under the kinetic point of view. In this sense, sand TS-2 represents a strong ally for improving the replacement efficiency, due to its capability to both improving the kinetic of the process and reducing the methane hydrate re-formation phenomena. The present study revealed that, with a simple analysis of properties of sediments containing hydrate reservoirs, it would be possible to establish the convenience of intervening with a replacement strategy instead of a classical application for simple methane recovery.

Ab-Initio Molecular Dynamics investigation of gas adsorption on α-quartz (001) for CO2 enhanced natural gas recovery

In this work, the interaction of methane and carbon dioxide on α-quartz with surface 001, with a siloxane termination (dense) surface was investigated by means of Ab-Initio Molecular Dynamics. Different temperatures were addressed, ranging from 298 to 423 K. For completeness, pure and mixed compositions were considered, to replicate the conditions present during Enhanced Gas Recovery processes by CO 2 injection. When considering pure compositions, both gases stick to the surface, except for the highest temperature (423 K), where most of CH 4 tend to desorb. When mixed compositions are addressed, carbon dioxide generally hinders the interaction of methane, except for high temperature, where both gases are equally distributed both close and far from the surface. To the goal of improving EGR processes on sandstone reservoirs, this work shows that a temperature of 323 K offers the best efficiency by increasing the interaction of carbon dioxide and pushing methane out of the surface. At the same time, this study would not recommend the use of very high temperatures (T > 373 K) and excessive concentration of CO 2 , as the majority of this gas would desorb, without improving methane extraction in a meaningful way. • With pure compositions, CH 4 possesses high mobility on α-quartz compared to CO 2 , though both gases are characterized by the same interaction. • At room temperature and mixed composition, both gases interact strongly with the surface, so the extraction of methane is usually inefficient. • A temperature of 323 K offers the best EGR efficiency, improving carbon dioxide interaction with the surface and pushing methane out. • Very high temperatures and excessive concentration of CO 2 could reduce gas recovery and sequestration.

Applying biochar under topsoil facilitates soil carbon sequestration: A case study in a dryland agricultural system on the Loess Plateau

The remarkable soil carbon sequestration and greenhouse gas mitigation effects of biochar have spurred great interest in exploring ways to maximize its benefits. However, it remains unclear how biochar application depth impacts soil carbon dioxide (CO2) emissions and methane (CH4) uptake in upland soil. Therefore, we carried out a 16-month field experiment in a dryland agricultural system to answer the above questions. Woody biochar (20 t ha−1) was mixed into three soil layers: 0–10 cm (BC0-10cm), 10–20 cm (BC10-20cm), and 0–20 cm (BC0-20cm). Soil without biochar addition was used as the control (CK). We monitored soil CO2 and CH4 fluxes continuously and determined the metabolic quotient (qCO2) and the sensitivity of soil respiration to temperature (Q10). The results indicated that CO2 emissions, CH4 uptake, qCO2 and Q10 were significantly affected by biochar application depth. Overall, compared with CK, BC0-10cm increased total CO2 emissions by 10.13%, while BC10-20cm and BC0-20cm showed no significant effect. BC0-10cm and BC0-20cm exhibited greater soil CH4 uptake enhancement than BC10-20cm, but the enhanced CH4 uptake resulted in limited net greenhouse gas mitigation. BC10-20cm and BC0-20cm had a lower qCO2 than the other treatments, which likely increased the carbon use efficiency and decreased the stress on soil microbes, but BC0-10cm showed the opposite effect. In addition, BC0-10cm significantly reduced Q10 mainly due to the enhanced lability of the native carbon and microbial activities. Changes in environmental factors in the 0–10 cm soil largely explained the variations in CO2 emissions, CH4 uptake and Q10 (>88%). Nevertheless, the enhanced microbial biomass in the 10–20 cm soil helped lower qCO2 in the whole 0–20 cm layer. In summary, adding biochar to surface soil (0–10 cm) likely accelerates carbon loss, due to the strong shift in the environment of the surface soil caused by complex interactions among hydrothermal conditions, nutrient levels (i.e., N, NH4+, NO3− and available P) and labile carbon. However, adding biochar to subsurface soil (10–20 cm) can effectively avoid severe disturbance of the surface soil environment and thus benefit soil carbon sequestration in the long term.

Mechanical behavior of hydrate-bearing sands with fine particles under isotropic and triaxial compression

The presence of fine particles has a significant impact on the mechanical behavior of hydrate-bearing sediments. In this study, a series of isotropic compression and triaxial tests were conducted using a customized testing system for the hydrate-bearing sediment. Carbon dioxide hydrate was formed in the host sediments, which were mixtures of sand and silty-sized quartzitic or illite fine particles. The isotropic and triaxial compression tests offered valuable datasets of the compression and the swelling indices, yielding stress, strength, stiffness, and dilatancy for hydrate-bearing sediments. The results highlighted that the addition of illite particles enhances compressibility but restricts stiffness and dilatancy. The strength is highly increased by hydrate saturation and less dependent on the mineralogy of fine particles. The cohesion is significantly enhanced by the hydrate saturation due to cementation. With the increasing hydrate saturation, the angle of internal friction increases slightly at lower hydrate saturation but it decreases slightly at higher hydrate saturation. The experimental results and mechanism analysis can be used to assess the stability of the hydrate reservoir under methane-carbon dioxide replacement and provide a reference to estimate the mechanical properties of the methane hydrate reservoir.

Enhanced CO2 methanation activity over Ni/CeO2 catalyst by one-pot method

Abstract Carbon dioxide hydrogenation for value-added chemicals has been regarded as a promising way for CO2 utilization. This paper describes the preparation of Ni/CeO2 catalysts derived from Ce-MOF precursor by impregnation or one-pot method and their application in carbon dioxide methanation. Various techniques were employed to characterize the prepared catalysts, including N2 adsorption–desorption, X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (SEM), H2-temperature programmed reduction (H2-TPR), H2-temperature programmed desorption (H2-TPD) and CO2-temperature programmed desorption (CO2-TPD). The results showed that compared with commercial CeO2 and CeO2 prepared by precipitation, CeO2 derived from Ce-MOF exhibited more oxygen vacancies and lower temperature reducibility, making it more beneficial for the adsorption and activation of CO2. Consequently, nickel supported on rod-shaped CeO2 derived from Ce-MOF exhibited higher CO2 conversion and methane selectivity at low temperatures. Furthermore, the Ni/CeO2−M-1 catalysts prepared by one-pot method showed superior activity since nickel could be partially incorporated into ceria lattice, leading to the formation of Ce1-xNixO2-y solid solutions and oxygen vacancies. The effect of nickel loading on the properties of the catalysts by one-pot method was also investigated, and the optimum Ni loading was 15 wt.% owing to the maximum number of oxygen vacancies being reached.

Evaluation of enhanced coalbed methane recovery and carbon dioxide sequestration potential in high volatile bituminous coal

Geologic sequestration of carbon dioxide (CO2) captured from flue gas into deep unmineable coal seams is a promising option to mitigate greenhouse gas emissions. Also, the injection costs can be partially or entirely offset by the revenue generated through the additional methane recovered. Complex phenomena occur during primary coalbed methane (CBM) recovery and CO2 injection for enhanced methane production and CO2 sequestration (CO2-ECBM). Numerical modeling and simulations can be used to represent these complex phenomena.This research investigates the CO2 storage capacity and CO2-ECBM recovery potential of a high volatile bituminous coal (Ferron coal) in Buzzard Bench, Uinta Basin. It is one of the most recognized coalbed methane producing areas in the U.S. and high-graded for evaluation due to its proximity to coal-fired power plants and CBM activity history. A three-dimensional geological model was first constructed with information available from the public domain. Available gamma-ray and density logs were utilized to develop the three-dimensional model of the coal seam and the overlying rocks using geostatistical techniques. This allows heterogeneity to be introduced in both vertical and horizontal directions, thereby creating a representational geologic model. After that, a dynamic reservoir model was constructed and calibrated against actual methane production using a history match. Simulations of CO2 injection and collateral methane production were carried out after the history match using two injectors and two production wells.The fluid flow simulation results demonstrated that it may be feasible to inject 1.16 million tons and sequester 1.15 million tons of CO2 over 20 years. Additionally, 13.95 billion cubic feet of methane were recovered within the same period. Due to the permeability reduction by coal matrix swelling, the methane recovered decreased by 19%, while the volume of CO2 injected decreased by 29%. This demonstrated injection feasibility, even in the presence of potential permeability reduction by coal matrix swelling during CO2 injection. Injection and production strategies are suggested to maximize injectivity and sequestration to overcome problems resulting from permeability changes and override.

Greenhouse gas emissions and cross-national happiness: a global perspective

This study examines how different forms of greenhouse gases affect happiness, along with other socioeconomic and demographic variables. The study uses a panel data analysis to investigate the relationship between happiness and greenhouse gases for 95 countries, spanning the period 1990–2015. The empirical analysis is based on different measures of greenhouse gases, such as carbon dioxide emissions (CO2), nitrous oxide (N2O), methane (CH4), and total greenhouse gases (GHG). The empirical results document that greenhouse gases have a strong negative impact on happiness. All forms of greenhouse gases adversely impact cross-national happiness. This study concludes that greenhouse gases are a significant source of lowering cross-national happiness levels, while economic affluence is improving life satisfaction. The findings remain robust to different specifications, alternative estimation methods, and additional control variables. The findings offer certain important policy implications, such as policymakers in these countries need to invest more in green technologies and green spaces to enhance their supply and accessibility.

The Analysis of a Prototype Installation for Biogas Production from Chosen Agricultural Substrates

Methane production by fermentation is a complex biochemical process, in which micromolecular organic substances are broken down by anaerobic bacteria into simple stabilized chemicals—mainly methane CH4 and carbon dioxide CO2. The organic matter of the slurry consists mainly of fats, proteins and carbohydrates. As a result of biochemical changes in the process of anaerobic decomposition, some of this matter is mineralized to simple chemical compounds. Cattle and pig husbandry offers enormous potential for useable biogas plant substrates. As a result of the constantly increasing amounts of animal husbandry products, and increasingly stringent environmental protection requirements aimed at reusing natural fertilizers, it is necessary to look for alternative processing methods. The need for efficiency in obtaining biogas from substrates (e.g., manure) was met by the laboratory stand presented in this article, for which the Polish patent No. 232200 was obtained. The new technology also allows leaching of the organic liquid, e.g., from manure, and subjecting it to methane fermentation. The solution allows the individual elements of the technological line that determine the fermentation process to be tested under laboratory conditions. It also allows testing of the substrates in terms of fermentation, to determine their physical and chemical characteristics, and then to characterize the fermentation process in terms of the quality and quantity of the resulting biogas and the quality of post-fermentation residues. Compressing biogas for local distribution was also proposed. As part of the research, using a laboratory stand, the organic matter was leached from manure, for the purpose of biogas production. In addition, the biogas yield from manure at varying degrees of maturity was assessed. The best properties in terms of biogas yield forecasting were demonstrated by manure composted for 4–8 weeks.

Revisiting Natural Resources—Globalization-Environmental Quality Nexus: Fresh Insights from South Asian Countries

Widespread interference of human activities has resulted in major environmental problems, including pollution, global warming, land degradation, and biodiversity loss, directly affecting the sustainability and quality of the environment and ecosystem. The study aims to address the impact of the extraction of natural resources and globalization on the environmental quality in the South Asian countries for the period 1991–2018. A new methodology Dynamic Common Correlated Effects is used to deal with cross-sectional dependence. Most previous studies use only carbon dioxide emissions, which is an inadequate measure of environmental quality. Besides carbon dioxide emissions, we have used other greenhouse gas emissions like nitrous oxide and methane emissions with a new indicator, “ecological footprint”. Long-run estimation results indicate a positive and significant relationship of natural resources with all greenhouse gas emissions and a negative association with the ecological footprint. Globalization shows a negative association with carbon dioxide emissions and nitrous oxide emissions and a positive relationship with the ecological footprint. Institutional performance is negatively correlated with carbon dioxide emissions, methane emissions, and ecological footprint while positively associated with nitrous oxide emissions. The overall findings highlight the pertinence of reducing greenhouse gas emissions and ecological footprint, proper utilizing of natural resources, enhancing globalization, and improving institutional performance to ensure environmental sustainability.

Water management and soil amendment for reducing emission factor and global warming potential but improving rice yield

Alternate wetting and drying (AWD) for growing rice improves water productivity (WP), minimize methane emission and net ecosystem carbon balance (CO2), but might be responsible for increased nitrous oxide emissions. The combined effects of water management and different organic manure application on methane emission, carbon dioxide and nitrous oxide fluxes, emission factor (EF) and WP are not well documented, which has been evaluated during dry seasons of 2018 and 2019. AWD and continuous flooding (CF) were imposed in NPKSZn, cowdung (CD), poultry manure (PM) and vermicompost (VC) treated plots. Closed chamber techniques were used for determining emissions of greenhouse gases. In comparison with CF, the AWD significantly reduced total GWP by 15–44% depending on soil amendments and 2–29% net ecosystem carbon balance (CO2); but additional N2O contribution to GWP was about 0.61–1.18% compared to sole chemical fertilizer treatments. Depending on soil amendments, the AWD reduced EF of CH4 (22–36%) but increased WP by 25–27% compared to CF system along with 14–43% reduction in GHG intensity (GHGI). Vermicompost treatment had the lowest GHG emission, GWP, EF and GHGI than cowdung, poultry manure under both irrigation methods. Rice yield varied because of soil amendments but not with irrigation methods. Use of vermicompost improved soil organic carbon (SOC) storage significantly than cowdung and poultry manure. In conclusion, AWD practice and amendment of rice soil with vermicompost could be an effective strategy for reducing GHG emission, GWP, EF and GHGI without sacrificing rice yield.

Experimental investigation of the use of methanotrophs for the degradation of low-concentration methane

Methanotrophs (methane-oxidizing bacteria) can degrade methane into carbon dioxide and water. In this paper, several types of methanotrophs have been successfully cultivated and sorted out based on microbial technology, and the processes and approaches used are described in detail. By using several types of active methanotrophs, a few groups of experimental investigations have been carried out to determine their degradation effects on methane gas; these studies used different low methane concentrations that were less than 1.5%. The experimental results showed that the methanotrophs studied can still show the characteristics of normal activity under the conditions of a series of low methane concentrations that ranged from 0.25 to 1.5%. In the degradation process, with the increased methane concentrations in the mixed gas, more methane could ultimately be degraded to carbon dioxide. The decrease in methane and increase in carbon dioxide presented approximately linear relationships, and the numerical relationships between carbon dioxide and methane and the microbial degradation times could be described by exponential functions with high correlations. The conclusions in this paper attempt to forge a new path for the prevention of exceeding limited methane concentrations during coal mining by the use of microbial technology.

ANALISIS REDUKSI POTENSI GAS METANA (CH4) PADA PENGOLAHAN LIMBAH CAIR PABRIK KELAPA SAWIT DENGAN METODE PENGOLAHAN MELALUI BIODIGESTER DAN KOLAM KONVENSIONAL

Research on the analysis of the reduction of the potential of methane gas (CH4) in the processing of palm oil mill effluent with the method of processing through Biodigester and Conventional ponds. Palm oil mill waste management system PT. The Indo Palm Fertile Core which reduces CH4 by splitting the effluent out of the inlet is divided into 2 lines, each pathway of the system aims to reduce methane gas (CH4) that comes from the degradation of organic matter present in the liquid waste. Sample analysis was taken from 6 palm oil mill waste processing ponds owned by PT. Inti Indosawit Subur Pelalawan. In this study the authors calculated repetition of sampling conducted using the Slovin technique. The measured parameters of wastewater are Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), pH and temperature in each pond that affects the formation of methane gas and carbon dioxide. Analysis of methane gas is determined in 1 way namely theoretically using equations and using the Biogas 5,000 Gas Analyzer tool. Calculation of methane gas potential (CH4) is carried out to find out how much the potential of methane gas (CH4) in each WWTP pond. From the calculation of the potential emissions of methane gas (CH4) it will be known how much reduction in methane gas (CH4) in the treatment of liquid waste in PKS PT. Inti Indosawit Subur Pelalawan Regency. Results of COD anasis and methane gas potential in biodigesters The average value of COD loading on Biodigester per day in September at the time of sampling was 24,884 kg / day. Potential emissions of methane captured in the Biodigester is 7,838.46 Nm3 / Day. The percentage of potential methane emissions in the Biodigester per day is 31.5%. Whereas the highest methane gas pool was found in pond 3, which is 6.4 Nm3 / day, which was calculated theoretically with a percentage of methane gas emissions of 0.011%. However, if measured using a tool, the percentage of potential methane gas in a 3 COD pool of 58,112 mg / L is 0% at a temperature of 35 ° C and a pH of 8.38. The highest methane gas emissions occur in pond 3 during the daytime with a value of 6.4 Nm3 / Day on the first day, 6.95 Nm3 / Day on the second day, 6.41 Nm3 / Day on the third day and 6.67 Nm3 / Day on the fourth day, the potential emissions of the biodigester have been calculated by the company. The potential of methane emissions captured in Biodigester is 7,838.46 Nm3 / Day with the percentage of potential methane emissions in Biodigester an average of 31.5% per day. The highest value of methane gas emissions during the 4 days of the study was 6.95 Nm3 / day on the second day taken at noon with a pool temperature of 35 ͦ C.

Ni–Fe, Co–Fe, and Co–Ni nanocomposites based on carbon nanotubes in the reaction of CO2 methanation

For effective carbon dioxide (CO2) methanation, bimetallic Co80Ni20/CNTs, Ni80Fe20/CNTs, and Co93Fe07/CNTs nanocomposite catalysts, where subscript numbers indicate the metal content (wt.%), have been prepared with wet impregnation method, further thermal decomposition, and chemical reduction stages using carbon nanotubes (CNTs) as a carrier. The catalysts were characterized using TG, SEM-EDX, argon physisorption, and X-ray powder diffraction methods. The pristine nanotubes demonstrated a slight activity in CO2 conversion due to the presence of small quantity of Ni. Among the tested nanocomposites the bimetallic Ni80Fe20/CNTs catalyst showed improved catalytic activity compared to Co80Ni20/CNTs and Co93Fe07/CNTs. The SEM-EDX analysis showed not uniform distribution of bimetallic aggregates on carbon nanotubes matrix for Ni80Fe20/CNTs and Co93Fe07/CNTs. However, this fact did not affect to catalytic properties of mentioned nanocomposites. Ni80Fe20/CNTs exhibited high activity in the CO2 methanation with 88% of CH4 yield at 350 °С unlike Co93Fe07/CNTs with 64% of CH4 yield.

Design and Control of a Fixed-Bed Recycle Reactor with Multicatalyst Layers: Methanation of Carbon Dioxide

The power-to-gas (PTG) process plays a significant role in transforming renewable electric energy into methane via electrolysis and methanation. Critical issues in the PTG process include the fluct...

Integrated nutrient management - promising way to reduce carbon dioxide and methane emission in flooded rice ecosystem: A review

Climate change is an inevitable ruling issue caused by the increasing concentration of greenhouse gases (GHG’s) in the atmosphere worldwide. It will have a considerable impact on agriculture and its related fields like live stocks and fisheries. In India, the main sectors contributing to these emissions are industry, agriculture and waste, with a total emission of 334 MT CO2 eq. Besides, the major sources in agriculture are enteric fermentation (63.4%), rice cultivation (20.9%), agricultural soils (13.0%), manure management (2.4%) and on-field burning is the crop residue (2.0%). Thus, the crop productivity sector (rice cultivation, soil and field burning of crop residues) contributes 35.9% to the total emission from agriculture. Therefore, reducing GHG emissions and enhancing the C sequestration in soil and biomass has become challenging. However, the total GHG’s emission from all sectors of the country has decreased from 33% in 1970 to 18% in 2010. Cutting off GHGs emission from agriculture can be achieved by sequestering C and reducing methane emissions(CH4) and carbon dioxide(CO2) through various soil and crop management strategies. Integrated nutrient management (INM) practice ensures the Soil –plant –atmospheric continuum (SPAC) in a promising way, reducing the GHGs emission by sequestering more carbon to soil than emissions. A studious prominent INM solution can be identified to develop a mitigation strategy that helps in climate change adaptation and sustains soil health through soil carbon sequestration.

Kinetics of hydrate formation, dissociation and reformation

Hydrates in natural sediments are never able to reach thermodynamic equilibrium because of in balance between number of independent thermodynamic variables and constraints (conservation and equilibrium conditions). In this work I present a consistent thermodynamic approach in which all components in all phases have the same reference state (ideal gas). Gibbs free energy and Enthalpy are modelled within the same concept and thermodynamic consistency is demonstrated though couplings between classical thermodynamics and statistical mechanics. The use of residual thermodynamics for all phases provides unique tools for comparing stability of different phases in terms of free energy. This is particularly important for hydrates forming from different phases. Since thermodynamic equilibrium is not possible then chemical potentials for guest molecules are not the same in each phase, Heterogeneous hydrate formation on gas/liquid interface will result in different hydrate than hydrate forming from dissolved hydrate former in water. It is also demonstrated that hydrate stability cannot be discussed in terms of independent thermodynamics variables like for instance temperature and pressure. As specific example we show that carbon dioxide is more stable than methane hydrate over the whole range of temperature and pressure. I also demonstrate that it is possible to modify Classical Nucleation Theory (CNT) though inclusion of a new mass transport term that also introduces an interface to the theory. As illustration we show that the modified CNT is able to predict experimental induction times for methane hydrate and carbon dioxide with very reasonable values for diffusivity coefficients on the liquid water side of hydrate/liquid water interface.