Separation Techniques

Biography

Biography: David Chiche

Abstract

Natural gases are commonly polluted with many contaminants such as sulfur compounds and CO2. Throughout the oil and gas treatment chain, various steps intended to separate most of the undesired compounds from the profitable part of the natural gas. Natural gas desulfurization is usually performed in generic treatment processes and in order to remove H2S and/or CO2 to meet the export gas specifications. However, commercial gas specifications are not restricted to H2S and CO2. New specifications have been imposed for many years to also remove most of other sulfur compounds from the natural gas. One of these, Carbonyl Sulfide (COS) is usually present in sour natural gases containing both H2S and CO2, in quantities which may exceed 200 vol. ppm. COSWEET^TM process, developed for the treatment of COS containing natural gases, is based on a combination of deacidification through any alkanolamine solution with a COS hydrolysis section over on a metal oxide based catalyst. Nearly complete COS conversion is reached, even at a relatively low operating temperature. Coupled with a classical sweetening unit, in which an adapted alkanolamine solvent is used in order to optimize the removal of H2S, CO2, as well as the H2S/CO2 selectivity, the high catalyst activity and the original integration of the scheme secure the COS removal at minimum extra cost. Benefits of capital and operating expenditures of the plant result both from the reduction of the absorption column and solvent flow rate and from the quality of the acid gas, which has positive consequences on the design of the sulfur recovery facilities units, including Claus unit.The approach set for the process development and the results obtained on COS conversion will be presented, as well as the model and simulation tool, and a case study showing the advantages of coupling COSWEET^TM to amine-based solvent.

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COSWEET^TM Process scheme

Publications

1. J. Magné-Drisch, J. Gazarian, S. Gonnard, J.M. Schweitzer, D. Chiche, G. Laborie, G. Perdu, COSWEET^TM: A New Process to Reach Very High COS Specification on Natural Gas Treatment Combined with Selective H₂S Removal, Oil Gas Sci Technol, 2016, 71, 40.
2. D. Chiche, J.M. Schweitzer, Investigation of competitive COS and HCN hydrolysis reactions upon an industrial catalyst: Langmuir-Hinshelwood kinetics modeling, Appl Catal B-Environ, 2017, 205, 189-200.
3. D. Chiche, C. Diverchy, A.-C. Lucquin, F. Porcheron, F. Defoort, Synthesis Gas Purification, Oil Gas Sci Technol, 2013, 68(4), 707-723.
4. V. Girard, D. Chiche, A. Baudot, D. Bazer-Bachi, I. Clémençon, F. Moreau, C. Geantet, Innovative low temperature regenerable zinc based mixed oxide sorbents for synthesis gas desulfurization, Fuel, 2015, 140, 453-461.
5. L. Neveux, D. Chiche, J. Perez-Pellitero, L. Favergeon, A.S. Gay, M. Pijolat, New insight into the ZnO sulfidation reaction: mechanism and kinetics modeling of the ZnS outward growth, Phys Chem Chem Phys, 2013, 15, 1532-1545.