scholarly journals Predicting sulfur solubility in hydrogen sulfide, carbon dioxide, and methane with an improved thermodynamic model

RSC Advances ◽  
2018 ◽  
Vol 8 (29) ◽  
pp. 16069-16081 ◽  
Author(s):  
Changjun Li ◽  
Gang Liu ◽  
Yang Peng
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Thermodynamic Model ◽  
Binary Interaction ◽  
Temperature Dependent ◽  
Interaction Coefficients ◽  
Sulfur Solubility

The binary interaction coefficients between sulfur and H2S, CO2or CH4are not constant, but temperature dependent. Three-parameter temperature-dependent equations for the binary interaction coefficients between sulfur and solvents are proposed.

Solid-Fluid Phase Equilibria Measurement for Mixtures of Methane, Carbon-Dioxide and N-Hexadecane

2021 ◽  
Author(s):  
Oluwakemi Victoria Eniolorunda ◽  
Antonin Chapoy ◽  
Rod Burgass
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Equation Of State ◽  
Phase Equilibria ◽  
Activity Coefficients ◽  
Fluid Phase ◽  
Ternary Mixtures ◽  
Binary Interaction ◽  
Thermodynamic Models ◽  
Methane Carbon

Abstract In this study, new experimental data using a reliable approach are reported for solid-fluid phase equilibrium of ternary mixtures of Methane-Carbon-dioxide- n-Hexadecane for 30-73 mol% CO2 and pressures up to 24 MPa. The effect of varying CO2 composition on the overall phase transition of the systems were investigated. Three thermodynamic models were used to predict the liquid phase fugacity, this includes the Peng Robison equation of state (PR-EoS), Soave Redlich-Kwong equation of state (SRK-EoS) and the Cubic plus Association (CPA) equation of state with the classical mixing rule and a group contribution approach for calculating binary interaction parameters in all cases. To describe the wax (solid) phase, three activity coefficient models based on the solid solution theory were investigated: the predictive universal quasichemical activity coefficients (UNIQUAC), Universal quasi-chemical Functional Group activity coefficients (UNIFAC) and the predictive Wilson approach. The solid-fluid equilibria experimental data gathered in this experimental work including those from saturated and under-saturated conditions were used to check the reliability of the various phase equilibria thermodynamic models.

Effect of Common Impurities on the Phase Behavior of Carbon-Dioxide-Rich Systems: Minimizing the Risk of Hydrate Formation and Two-Phase Flow

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 921-930 ◽  
Author(s):  
Antonin Chapoy ◽  
Rod Burgass ◽  
Bahman Tohidi ◽  
J. Michael Austell ◽  
Charles Eickhoff
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Phase Behavior ◽  
Water Content ◽  
Thermodynamic Model ◽  
Two Phase Flow ◽  
Hydrate Formation ◽  
Experimental Methodology ◽  
Phase Flow ◽  
Two Phase

Summary Carbon dioxide (CO2) produced by carbon-capture processes is generally not pure and can contain impurities such as N2, H2, CO, H2 S, and water. The presence of these impurities could lead to challenging flow-assurance issues. The presence of water may result in ice or gas-hydrate formation and cause blockage. Reducing the water content is commonly required to reduce the potential for corrosion, but, for an offshore pipeline system, it is also used as a means of preventing gas-hydrate problems; however, there is little information on the dehydration requirements. Furthermore, the gaseous CO2-rich stream is generally compressed to be transported as liquid or dense-phase in order to avoid two-phase flow and increase in the density of the system. The presence of impurities will also change the system's bubblepoint pressure, hence affecting the compression requirement. The aim of this study is to evaluate the risk of hydrate formation in a CO2-rich stream and to study the phase behavior of CO2 in the presence of common impurities. An experimental methodology was developed for measuring water content in a CO2-rich phase in equilibrium with hydrates. The water content in equilibrium with hydrates at simulated pipeline conditions (e.g., 4°C and up to 190 bar) as well as after simulated choke conditions (e.g., at -2°C and approximately 50 bar) was measured for pure CO2 and a mixture of 2 mol% H2 and 98 mol% CO2. Bubblepoint measurements were also taken for this binary mixture for temperatures ranging from -20 to 25°C. A thermodynamic approach was employed to model the phase equilibria. The experimental data available in the literature on gas solubility in water in binary systems were used in tuning the binary interaction parameters (BIPs). The thermodynamic model was used to predict the phase behavior and the hydrate-dissociation conditions of various CO2-rich streams in the presence of free water and various levels of dehydration (250 and 500 ppm). The results are in good agreement with the available experimental data. The developed experimental methodology and thermodynamic model could provide the necessary data in determining the required dehydration level for CO2-rich systems, as well as minimum pipeline pressure required to avoid two-phase flow, hydrates, and water condensation.

Ammonia and other microclimatic conditions at an Australian pre-export sheep assembly depot

2013 ◽  
Vol 53 (6) ◽  
pp. 580
Author(s):  
Mathew K. Pines ◽  
Tracy Muller ◽  
Clive J. C. Phillips
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Moisture Content ◽  
Gaseous Emissions ◽  
Housing Systems ◽  
Health And Wellbeing ◽  
Ammonia Accumulation ◽  
Animal Excreta ◽  
Microclimatic Conditions ◽  
Positive Correlations

Noxious gases produced at hazardous concentrations in animal housing systems may affect the health and wellbeing of both animals and workers. In order to determine if the gaseous emissions from a pre-export assembly depot for sheep constituted a risk, atmospheric ammonia was measured in eight sheep buildings at an Australian assembly depot. Additionally, meteorological variables and distance from excreta were measured to determine their influence on ammonia, carbon dioxide and hydrogen sulfide concentrations. Repeat measurements were made at 12 sites in each building on 4 separate days, and four buildings were mapped using longitudinal and latitudinal transects. Concentrations of ammonia, carbon dioxide and hydrogen sulfide were all below the recommended safety thresholds for humans and livestock. There were positive correlations between ammonia and the following variables: ambient temperature and moisture content, and negative correlations with distance from animal excreta. Understanding these relationships will help to understand the reasons for ammonia accumulation in such buildings.

scholarly journals Stan i perspektywy wykorzystania biogazu jako nośnika energii do zastosowań stacjonarnych i środków transportu

2012 ◽  
Vol 10 (3) ◽  
pp. 97-118
Author(s):  
Krzysztof Biernat ◽  
Izabela Różnicka
Keyword(s):  
Carbon Dioxide ◽  
Renewable Energy ◽  
Hydrogen Sulfide ◽  
Energy Balance ◽  
Sewage Sludge ◽  
Motor Fuel ◽  
International Programs ◽  
Biogas Upgrading ◽  
Compressed Natural Gas ◽  
Production Of Hydrogen

Both governmental and international programs support the promotion of biofuels and aim to increase the limit of renewable energy used in the fuel energy balance. Biogas is produced during the anaerobic methane fermentationprocess and it is known as a significant source of renewable energy, contributing to agriculture and environmental protection. Three types of biogas can be distinguished: biogas from sewage sludge, biogas collected from land`fils, andagricultural biogas. There are several possibilities of using upgraded biogas. Biogas can be used in cogeneration systems to provide heat and electricity, in transportation as a motor fuel and in the production of biohydrogen. Biogas upgrading process leads to a product which is characterized by the same parameters as compressed natural gas. Direct biogas use in the production of hydrogen is possible because of prior purification from traces like hydrogen sulfide, except carbon dioxide, by which the reaction can proceed in the desired manner.

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