Investigating the effect of ZnO adsorbent properties on natural gas desulfurization process to evaluate the performance of the adsorbents

Document Type : Research paper

Authors

1 Chemical Engineering Department, Kermanshah University of Technology

2 Chemical Engineering Department, Faculty of Energy, Kermanshah University of ‎Technology

Abstract

Sulfur is a toxic agent to most catalysts of the unit. Therefore, to eliminate the sulfur, the processes of hydrogenation and desulfurization should be performed on the feed gas. In this research, natural gas desulfurization process by zinc oxide adsorbent was model by using grain model. In order to analyze the adsorbent properties, two commercial samples were tested by BET, XRF, SEM and mercury porosimetry. The results showed that the model with an error of less than 2% corresponds to experimental data. The obtained results from sensitivity analysis indicated that the pellet porosity has the highest breakthrough time within 0.4-0.55. It was also found that by increasing of the bulk density, breakthrough time increases, but also it increases the pressure drop of the bed. Comparing the breakthrough time and conversion of commercial adsorbents samples, it was observed that Topsoe commercial adsorbent (1) had a better performance than Sud-chemie commercial adsorbent for specific operational conditions. The breakthrough time and the conversion of commercial adsorbent 1 has been calculated 215 days and 90%, respectively, and for commercial adsorption 2, 185 days and 87% respectively

Keywords

Main Subjects


[1] Atimtay, A.T.(2001), Cleaner energy production with integrated gasification combined cycle systems and use of metal oxide sorbents for H 2 S cleanup from coal gas. Clean products and processes, 2(4): p. 197-208.[1]
 ##
[2] Novochinskii, I.I., et al.,(2004). Low-temperature H2S removal from steam-containing gas mixtures with ZnO for fuel cell application. 1. ZnO particles and extrudates. Energy & Fuels,  18(2): p. 576-583.
 ##
[3] Gibson III, J.B. and D.P. Harrison,(1980). The reaction between hydrogen sulfide and spherical pellets of zinc oxide. Industrial & Engineering Chemistry Process Design and Development, 19(2): p. 231-237.
 ##
[4] Nashtaee, P.S.b. and B. Khoshandam, (2014). Noncatalytic gas-solid reactions in packed bed reactors: a comparison between numerical and approximate solution techniques. Chemical Engineering Communications,201(1): p. 120-152.
 ##
[5] Sampath, B., P. Ramachandran, and R. Hughes, (1975). Modelling of non-catalytic gas—solid reactions—II. Transient simulation of a packed bed reactor. Chemical Engineering Science, 30(1): p. 135-143.
 ##
[6] Hastaoglu, M.A. and B.E. Jibril,(2003).Transient modeling of hydrodesulfurization in a fixed-bed reactor. Chemical Engineering Communications, 190(2): p. 151-170.
 ##
[7] Sohn, H. and J. Szekely, (1972). A structural model for gas-solid reactions with a moving boundary—III: A general dimensionless representation of the irreversible reaction between a porous solid and a reactant gas. Chemical Engineering Science, 27(4): p. 763-778.
 ##
[8] AFSHAR, E.A. and E.H. ALE, (2012). Solution of Noncatalytic Packed Bed Reactors Equations by Finite Element Method.
##
[9] Maya, J.C. and F.C. Janna, (2016).Novel model for non catalytic solid–gas reactions with structural changes by chemical reaction and sintering. Chemical Engineering Science, 142: p.2.268—58.
 ##
[10] Szekely, J. and C. Lin, (1976). The reduction of nickel oxide disks with carbon monoxide. Metallurgical Transactions B, 7(3): p. 493-495.
 ##
[11] Parandin, M.S. and H. Rashidi, (2018). Deep desulfurization of natural gas by a commercial ZnO adsorbent: A mathematical study for fixed-bed reactors. Journal of Natural Gas Science and Engineering, 59: p. 116-123.
 ##
[12] Monazam, E.R., L.J. Shadle, and D.A. Berry,(2008) Modeling and analysis of S-sorption with ZnO in a transport reactor. Chemical Engineering Science. (10)13: p. 2614-2623.
 ##
]13[یوند واله, شیدا؛ حامد رشیدی و گلشن سیاحت شایسته، ۱۳۹۵، مطالعه CFD توزیع جریان گاز طبیعی در راکتور جداسازی سولفید هیدروژن، سومین کنفرانس بین المللیدستاوردهای نوین پژوهشی در شیمی و مهندسی شیمی، تهران، کنفدراسیون بین المللی مخترعان جهان.
 ##
[14] Khoshandam, B., R. Kumar, and E. Jamshidi,(2005). Simulation of non-catalytic gas–solid reactions: application of grain model for the reduction of cobalt oxide with methane. Mineral Processing and Extractive Metallurgy, 114(1): p. 10-22.
 ##
[15] Turton, R., et al., (2004). Evaluation of zinc oxide sorbents in a pilot-scale transport reactor: sulfidation kinetics and reactor modeling. Industrial & Engineering Chemistry Research,43(5): p. 1235-1243.
 ##
[16] Rashidi, H., H.A. Ebrahim, and B. Dabir,(2013). Reduction kinetics of nickel oxide by methane as reducing agent based on thermogravimetry. Thermochimica acta, 561: p. 41-48.
 ##
[17] Bird, R., W. Stewart, and E. Lightfoot, (2007) Transport Phenomena (revised second ed.) John Wiley & Sons. New York.
 ##
[18] Rosso, I., et al.,(2003). Zinc oxide sorbents for the removal of hydrogen sulfide from syngas. Industrial & Engineering Chemistry Research, 42(8): p. 1688-1697.
 ##
[19] Green, D.W. and R.H. Perry,(1973). Perry's Chemical Engineers' Handbook/edición Don W. Green y Robert H. Perry.
 ##
[20] Salatino, P. and L.(1990). Massimilla, Pressure drop in flow of a nearly critical fluid through packed beds of spheres. Chemical Engineering Communications, 93(1): p. 101-109.