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.
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Abbreviations
- C in :
-
Concentrations of mercaptan in the inlet streams (mg/m3)
- C out :
-
Concentrations of mercaptan in the outlet streams (mg/m3)
- C * :
-
C* is the equilibrium concentration of the mercaptan (mg/m3)
- E :
-
Removal efficiency (−)
- K L a :
-
Volumetric mass transfer coefficient (1/s)
- Q inj :
-
Injection volumetric flow rate (mL/s)
- Q main :
-
Main volumetric flow rate (mL/s)
- t m :
-
Residence time of mixture two stream (s)
- V :
-
Total volume of mixing line (m3)
- in:
-
Inlet
- out:
-
Outlet
- inj:
-
Injection
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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.
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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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Parvareh, A., Parvizi, F. Laboratory-scale study of mercaptan removal from LPG in the presence of passive mixing tools. Int. J. Environ. Sci. Technol. 17, 3199–3208 (2020). https://doi.org/10.1007/s13762-019-02561-7
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DOI: https://doi.org/10.1007/s13762-019-02561-7