Accurate Thermodynamic Model for the Calculation of H₂S Solubility in Pure Water and Brines

Abstract

A thermodynamic model calculating the solubility of hydrogen sulfide (H 2 S) in pure water and in aqueous NaCl solutions (0-6 M, 273-500 K, 0-200 bar) is presented. The model is based on a specific particle interaction theory for the liquid phase and a highly accurate equation of state for the vapor phase. With this specific interaction approach, this model is able to predict H 2 S solubility in other systems, such as H 2 S-H 2 O-Na 2 SO 4 , H 2 S-H 2 O-CaCl 2 , H 2 S-H 2 O-KCl, and H 2 S-seawater, without fitting experimental data from these systems. Comparison of the model predictions with experimental data indicates that the model is within or close to experimental uncertainty, which is about 7% in H 2 S solubility. The model is programmed and can be downloaded from the website: www.geochem-model.org/programs.htm. Online calculation is also made available on the website: www.geochem-model.org/models.htm. The H 2 S solubility model can be used together with numerical speciation-solubility modeling codes such as PHREEQC to calculate sulfide mineral solubility in H 2 S saturated brines. An example calculation for galena solubility is given.

Modeling Studies on the Transport of Benzene and H2S in CO2-Water Systems

“… Incorporation of phase-partitioning relationships and transport capabilities for benzene, water, and SCC mixtures, using data from the literature  Incorporation of aqueous CO 2 solubility modules from module ECO2N )  Incorporation of aqueous H 2 S solubilities from the model presented by Duan et al (2007) Organic compounds that could potentially be mobilized by SCC were evaluated in terms of probability of occurrence and abundance in deep storage formations, as well as potential for environmental hazard. Benzene, PAHs, and phenols were identified as good candidates for further evaluation.…”

“… Incorporation of phase-partitioning relationships and transport capabilities for benzene, water, and SCC mixtures, using data from the literature;  Incorporation of aqueous CO 2 solubility modules from module ECO2N and verifying its functionality against published data;  Incorporation of aqueous H 2 S solubilities from the model presented by Duan et al (2007) and verification against published data.…”

“…with parameters c 1 -c 8 given by Duan et al (2007, . Here, however, we use the equation presented by Drummond (1981), which is more easily implemented and provides results very close to those of Duan et al (2007):…”

“…Reviews of H 2 S solubility in water and brines are presented by Chapoy et al (2005), Duan et al (2007), and Koschel et al (2007), as well as in an earlier study by Carroll and Mather (1989). Table A5 summarizes some of the existing data at conditions of interest for CO 2 geological sequestration.…”

Removal of hydrogen sulfide by zinc oxide nanoparticles in drilling fluid

“…It is a corrosive (Duan et al,2007;Perdomo et al,2002;Ren et al,2005) and highly toxic gas and it can be regarded as a major source of air pollution ( Haimour et al,2005). According to the international environmental regulations, H 2 S contained in the acid gases should be effectively removed before emission to atmosphere.…”