(400g) Sorption of Hydrogen Sulfide From Natural Gas Using Physicochemical Treated Fly Ash

Sorption of Hydrogen Sulfide from Natural Gas using Physicochemical Treated Fly Ash

¹Zahir Aslam, *¹Reyad A. Shawabkeh, ¹Ibnelwaleed Hussien, ¹Nadhir Al-Bagli

¹ Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia

*  AIChE members, corresponding Author, rshawabk@kfupm.edu.sa

Existing of acidic gases in natural gas causes major problems in gas processing industry.  Hydrogen sulfide, for example, is certainly highly corrosive and hazardous material as it is flammable and poisonous to humans and animals, which can be lethal at 350 ppm level. Several attempts were made to remove H2S from upper- and down streams.  The most widely used removal technique is chemical absorption and neutralization by amine solution. Although this technique is the most commonly used as gas separation process in the petrochemical industries, it suffers from numerous problems including: high-energy requirements, corrosion, and susceptibility to foaming. Alternatively, adsorption process is used with an efficient manner. Numerous adsorbents were used to clean up these toxicants from sour gases. Activated ash is intensively used in treatment of sulfur dioxide, carbon dioxide, and hydrogen sulfide in upstream gases ¹. Other adsorbents such as fly ash, titanium dioxide and synthetic and natural zeolite are also used ^2,3.

In this work fly ash was chemically treated with different concentrations of mixed sulfuric, nitric and phosphoric acids, followed by physical activation in CO₂ atmosphere at 330 ^oC.  Then the treated ash samples were refluxed over night with diethanol amine, filtered, dried and characterized according to their surface area, pore size distribution, surface morphology, surface functional groups, and acidity.

BET Surface area and pore volume using N₂ adsorption at 77 K showed an increase from 68 to 318 m²/g and from 0.036 to 0.678 cm³/g, respectively, with average pore diameter of 13.28. SEM morphology illustrated porous, spherical particles with an average particle size of 50 µm.  FTIR analysis provided the existence of amine functional groups appeared at 3178, 2929 and 2770 cm^-1.

The treated fly ash was tested for adsorption of H₂S and found that both chemical and physical adsorption of H₂S takes place on the surface of the treated ash. Results of isotherm and kinetic studies will be presented and provided in the extended abstract (paper).

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2.       Irfan MF, Goo JH, Kim SD. Effects of NO, NO2, CO and SO2 on NO oxidation over Pt/TiO2 for hybrid fast SCR process. Environmentalist.1-7.

3.       Bai Xf, Cao Y, Wu W. Photocatalytic decomposition of H2S to produce H2 over CdS nanoparticles formed in HY-zeolite pore. Renewable Energy.