Methane diffusion coefficient in compost and soil–compost mixtures in gas phase biofilter

Pokhrel, Dinesh; Hettiaratchi, Patrick; Kumar, Sunil

doi:10.1016/j.cej.2011.03.013

Cited by 22 publications

(6 citation statements)

References 32 publications

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“…Also, the uneven distribution of water in soil will also lead to irregular distribution of methane. 22 , 23 During long distance transportation, natural gas pipelines pass through different geological structures, in suburban areas, of a porous media consisting of soil, gravel, and asphalt near towns, and of backfill, soil, gravel, and cement concrete or asphalt in towns. The diffusion of methane in the layered structure composed of sand, gravel, and asphalt has been investigated by large-scale experiments.…”

Section: Introductionmentioning

confidence: 99%

“…In the soil, the diffusion rate of natural gas becomes faster, the time for diffusion to reach the steady state is shortened, and the gas concentration increases when the porosity or granule diameter increases. − The increase of water content will indirectly reduce the number of aeration pores in soil, which will impede the diffusion of methane and reduce its diffusion rate. Also, the uneven distribution of water in soil will also lead to irregular distribution of methane. , During long distance transportation, natural gas pipelines pass through different geological structures, in suburban areas, of a porous media consisting of soil, gravel, and asphalt near towns, and of backfill, soil, gravel, and cement concrete or asphalt in towns. The diffusion of methane in the layered structure composed of sand, gravel, and asphalt has been investigated by large-scale experiments .…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Numerical Prediction Model for the Dangerous Radius of Natural Gas Leakage in Soil

Ren

Liu

et al. 2022

ACS Omega

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Prediction of the dangerous radius of natural gas plays an important role in reducing the hazards of a buried natural gas pipeline after leakage. The factors affecting the diffusion law of natural gas in soil after leakage are mainly divided into the pipe, soil, and environmental sides. Previous studies focused on the effects of leakage pressure, leakage aperture, and leakage direction on the pipe side and porosity and water content on the soil side. In this paper, experiments and numerical simulations are conducted for further investigating the effects on the diffusion of natural gas in soil of the soil type (porosity and granule diameter) and layered structure among the soil side factors and soil temperature as environmental side factors. The contour radius corresponding to 5% volume concentration (the lower limit of natural gas explosion in soil) is defined as the natural gas dangerous radius for analysis. Based on comprehensive analysis of the effects of the factors, a prediction model is proposed for the dangerous radius of natural gas in soil with leakage pressure, leakage aperture, porosity, and granule diameter as the dominant influencing factors, which is of great significance for locating the source of the leakage.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Prediction Model for the Dangerous Radius of Natural Gas Leakage in Soil

Ren

Liu

et al. 2022

ACS Omega

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“…The diffusion coefficient of gas in heavy oil is required to study the recovery processes. It is also widely applied in analyzing solubility trapping of greenhouse gas in formations brine . The techniques of measuring diffusion coefficient of gas in the liquid can include direct methods and indirect methods .…”

Section: Introductionmentioning

confidence: 99%

“…The diffusion coefficient is determined by fitting the corresponding diffusion mathematical model with the pressure‐decay data vs. time. The method has been widely used to study diffusion of gases in heavy oil and bitumen and diffusion of CO 2 in water . If the pressure‐decay technique is used to measure the mass transfer of CO 2 in water, the density‐driven convection needs to be considered …”

Section: Introductionmentioning

confidence: 99%

An analytical method of estimating diffusion coefficients of gases in liquids from pressure decay tests

2018

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We present an exact solution of quasi-equilibrium model, based on pressure decay technique, to measure diffusion coefficient. The results of the quasi-equilibrium model are compared with the traditional equilibrium model and it was found that the latter is only a special case of former one. We provide new approximate solution to estimate diffusion coefficient that is more convenient to use, compared with the previously reported approaches. It also reveals that our solution is capable of taking into account greater portion of the collected pressure decay test data and is more accurate. Based on the developed solution, estimation approaches, including linear method and exponential method, are presented and applied to analyze synthetic and experimental pressure-decay data. The quasi-equilibrium model is also compared with the traditional equilibrium model. The results reveal that analysis of the test data using equilibrium model may introduce large error in estimation of diffusion coefficient.

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“…The models fit experimental data to varying degrees based on the number of parameters used, demonstrating the need for a modified thermal conductivity-water content model for soil mixtures. Pokhrel et al (2011) studied the gas diffusivity-air content relation in different soil-compost mixtures to be applied in gas-phase biofilters. They highlighted the limited applicability of widely used predictive models to accurately describe gas diffusivity in soil-compost mixtures.…”

mentioning

confidence: 99%

Characterization of Grain‐Size Distribution, Thermal Conductivity, and Gas Diffusivity in Variably Saturated Binary Sand Mixtures

Deepagoda

Smits

Jayarathne

et al. 2018

Vadose Zone Journal

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Characterization of differently textured porous materials, as well as different volumetric porous media mixtures, in relation to mass and heat transport is vital for many engineering and research applications. Functional relations describing physical (e.g., grain-size distribution, total porosity), thermal, and gas diffusion properties of porous media and mixtures are necessary to optimize the design of porous systems that involve heat and gas transport processes. However, only a limited number of studies provide characterization of soil physical, thermal, and gas diffusion properties and the functional relationships of these properties under varying soil water contents, especially for soil mixtures, complicating optimization efforts. To better understand how mixing controls the physical, thermal, and gas diffusion properties of porous media, a set of laboratory experiments was performed using five volumetric mixtures of coarse-and fine-grained sand particles. For each mixture, the grain-size distribution (GSD), thermal conductivity, and gas diffusivity were obtained and parameterized using existing and suggested parametric models. Results show that the extended, two-region Rosin-Rammler particle-size distribution model proposed in this study could successfully describe the bimodal behavior of the GSD of binary mixtures. Further, the modified Côté and Konrad thermal conductivity model adequately described the thermal conductivity-water saturation relations observed in different mixtures. The proposed simple soil-gas diffusivity descriptive model parameterized the upper limit, average, and lower limit behavior in gas diffusivity-air content relations in apparently texture-invariant gas diffusivity data. Results further show a close analogy between gas diffusivity and thermal conductivity and their variation with saturation across different binary mixtures. Overall, the results of the study provide useful numerical insight into the physical, thermal, and gas transport characteristics of binary mixtures, with wide implications for future engineering and research applications that involve multicomponent porous systems. . 2018. Characterization of grainsize distribution, thermal conductivity, and gas diffusivity in variably saturated binary sand mixtures. Vadose Zone J. 17:180026.

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Methane diffusion coefficient in compost and soil–compost mixtures in gas phase biofilter

Cited by 22 publications

References 32 publications

Experimental and Numerical Prediction Model for the Dangerous Radius of Natural Gas Leakage in Soil

Experimental and Numerical Prediction Model for the Dangerous Radius of Natural Gas Leakage in Soil

An analytical method of estimating diffusion coefficients of gases in liquids from pressure decay tests

Characterization of Grain‐Size Distribution, Thermal Conductivity, and Gas Diffusivity in Variably Saturated Binary Sand Mixtures

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