Hydrogen Sulfide and Carbon Dioxide Removal from Dry Fuel Gas Streams Using an Ionic Liquid as a Physical Solvent^†‡

Abstract

The mole fraction solubilities (x*) and volumetric liquid-side mass-transfer coefficients (k L a) for H 2 S and CO 2 in the ionic liquid, TEGO IL K5, (a quaternary ammonium polyether) were measured under different pressures (up to 30 bar) and temperatures (up to 500 K) in a 4 L ZipperClave agitated reactor. CO 2 and N 2 , as single gases, and a H 2 S/N 2 gaseous mixture were used in the experiments. The solubilities of H 2 S and CO 2 were found to increase with pressure and decrease with temperature within the experimental conditions used. The H 2 S solubilities in the ionic liquid (IL) were greater than those of CO 2 within the temperature range investigated (300-500 K) up to a H 2 S partial pressure of 2.33 bar. Hence, the IL can be effectively used to capture both H 2 S and CO 2 from dry fuel gas stream within the temperature range from 300 to 500 K under a total pressure up to 30 bar. The presence of H 2 S in the H 2 S/N 2 mixture created mass-transfer resistance, which decreased k L a values for N 2 . The k L a and x* values of CO 2 were found to be greater than those of N 2 in the IL, which highlight the stronger selectivity of this physical solvent toward CO 2 than toward N 2 . In addition, within the temperature range from 300 to 500 K, the solubility and k L a of H 2 S in the IL were greater than those of CO 2 , suggesting that not only can H 2 S be more easily captured from dry fuel gas streams but also a shorter absorber can be employed for H 2 S capture than that for CO 2 . † Progress in Coal-Based Energy and Fuel Production.

Synthesis, characterization and application of 1-(2-cyanoethyl)-3-(3-methoxypropane)imidazolium bromide for CO2capture

“…[14]. Besides, high CO2 solubility can also be correlated with the nitrile group that weakens the cation-anion interaction [7].…”

Methodology of non-equilibrium thermodynamics for kinetics research of CO2 capture by ionic liquids

“…Their research results show that the measured CO 2 diffusion coefficients in the ILs are dependent on the ionic liquid cation as well as the anion, and the measured CO 2 diffusion coefficients are sensitive to temperature. Heintz et al [74] measured the volumetric liquid-phase mass transfer coefficients of CO 2 and H 2 S in the ionic liquid TEGOIL K5 at different temperatures up to 500 K and different pressures up to 3 MPa in a 4 L ZipperClave agitated reactor. Their research results show that the liquid-phase mass transfer coefficients of H 2 S in the IL are larger than those of CO 2 in the IL at the temperature range of 300-500 K, which indicates that H 2 S can be more easily captured from the dry fuel gas streams and shorter absorbers can be developed for H 2 S capture than that for CO 2 capture.…”

“…In the absorption kinetics investigations of CO 2 and H 2 S in the ionic liquid TEGOIL K5 performed by Heintz et al [74], an instantaneous equilibrium at the interface was considered. In the CO 2 dissolution kinetics investigations in brines by Ji et al [111], the concentration of CO 2 (aq) at the vapor-liquid interface was considered as the instantaneous equilibrium concentration.…”

Perspectives of Ionic Liquids Applications for Clean Oilfield Technologies

“…During the present century, a big number of studies have been performed to explore the prospects of ILs for gases separation and for founding the best prototypes for CO 2 capture (Bates et al, 2002, Baltus et al, 2004, Baltus et al, 2005, Shiflett & Yokozeki, 2005, Jacquemin et al, 2006, Hou & Baltus, 2007, . Schilderman et al, 2007, Yokozeki & Shiflett, 2007, Sánchez et al, 2007, Ventura et al, 2008, Camper et al, 2008, Soriano et al, 2008, Soriano et al, 2009, Heintz et al, 2009, a, b. Carvalho et al, 2009, Kuleman et al, 2010, Shokouhi et al, 2010 and also several discoveries have been patented (Brennecke & Maginn, 2002, Davis Jr., 2004, Chinn et al, 2006. Oleffin/paraffin separation is other very important separation process in refineries.…”