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Laboratory-scale study of mercaptan removal from LPG in the presence of passive mixing tools

  • A. ParvarehEmail author
  • F. Parvizi
Original Paper
  • 3 Downloads

Abstract

The aim of this laboratory-scale study is to propose a practical method for better mixing and mercaptan removal from an industrial feed. The role of proper mixing for mercaptan removal from an industrial LPG stream using a commercial mercaptan scavenger has been investigated in the laboratory scale. The LPG obtained from the Ilam Gas Treating Company includes a very high concentration of mercaptan, and intense environmental pollution will occur during carrying this product to other refineries. The effect of the mixer length, including 20 and 40 cm, and element pitches, including 1, 2 and 3 mm, as well as the LPG stream flow rates, including 2, 18 and 30 mL/s, on the mercaptan removal efficiency and the mass transfer coefficient was investigated using UOP 163 standard method. The mercaptan removal efficiency was enhanced 15.2, 18.1 and 19.7% for a mixer length of 20 cm and element pitch 1 mm at 2, 18 and 30 mL/s flow rates, respectively. Similarly, for the mixer length of 40 cm and element pitch 1 mm, the largest enhancement 23% of the mercaptan removal efficiency was obtained. In addition, the mass transfer coefficient will increase as the flow rate increases, and the mixer pitch decreases.

Keywords

Mercaptan Environmental protection Static mixer LPG Mixer length Mixer element pitch 

List of symbols

Cin

Concentrations of mercaptan in the inlet streams (mg/m3)

Cout

Concentrations of mercaptan in the outlet streams (mg/m3)

C*

C* is the equilibrium concentration of the mercaptan (mg/m3)

E

Removal efficiency (−)

KLa

Volumetric mass transfer coefficient (1/s)

Qinj

Injection volumetric flow rate (mL/s)

Qmain

Main volumetric flow rate (mL/s)

tm

Residence time of mixture two stream (s)

V

Total volume of mixing line (m3)

Subscripts

in

Inlet

out

Outlet

inj

Injection

Notes

Acknowledgements

The authors wish to express their thanks to the Ilam Gas Treating Company (IGTC) of Iran for preparing the LPG and mercaptan scavenger as well as the mercaptan measurement facility.

Compliance with ethical standards

Conflict of interest

The authors certify that they have NO affiliations with or involvement in any organization or entity with any financial interest, or non-financial interest in the subject matter or materials discussed in this manuscript, and there is no conflict of interest concerning this study.

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Copyright information

© Islamic Azad University (IAU) 2019

Authors and Affiliations

  1. 1.Faculty of Petroleum and Chemical Engineering, CFD Research CenterRazi UniversityKermanshahIran

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