(A Report on Dissertation II )
Submitted as a part of course work in M. Tech (Gas Engineering) By Prakash Mukhopadhyay, B. E (Chemical Engg.)
Under the Guidance of Mr. J. S. Prasad, Associate Professor UPES - Rajahmundry
COLLEGE OF ENGINEERING STUDIES UNIVERSITY OF PETROLEUM AND ENERGY STUDIES Regional Centre: Rajahmundry Andhra Pradesh-533 294 2008-2009
First of all I acknowledge, the grace of God the Almighty, in this arduous journey. I would like to thank my parents for their love, care and support without which I wouldn’t have been able to complete the project. I avail this opportunity to thank Prof. K. V. Rao, Academic Head, College of Engineering, UPES, Rajahmundry and Dr. K V Mohana Rao, Centre Director, UPES, Rajahmundry for successful completion of this project. I express my deepest sense of gratitude to Mr. J. S. Prasad, Associate Professor, UPES, Rajahmundry for his guidance and inspiration throughout this project. It has been an experience of great pleasure and satisfaction. Finally I express sincere thanks to all my colleagues, who helped to complete this arduous task directly or indirectly.
EXTENDED ABSTRACT Part I -- The objective of this project is to design a sour gas treatment plant using appropriate solvent. Natural gas with a flow rate of 60MMSCFD (2988.27 Kgmol/hr) with 9 mole% H2 S and is considered. If the outlet H2 S in the Natural gas required is 4ppm then using the process selection figures, the suitable solvents for treating this gas stream are Sulfinol-D, Sulfinol-M, DIPA, MDEA, & ADIP. Sulfinol, as known in basic form consisting of DIPA & Sulfolane is selected as the solvent for the design. The process chemistry of Sulfinol is explained and the equipments involved in the flow sheet are described. Gas properties like molecular weight, specific gravity, compressibility and density are calculated. For initial separation of liquid (i.e., 2000 BOPD) a vertical separator is designed. Absorption tower is assumed to operate at 973 psia and 1090 F. Sulfinol circulation rate, tower diameter, weir height, Clear liquid Residence Time (CLRT), No of real trays required and shell thickness required for absorption are calculated. After absorption tower, a Flash-drum to vent off the absorbed gases by reducing the pressure to 80.85psia is sized (diameter and length of flash drum is calculated). Two heat exchangers, one for heat transfer between rich/lean solvent and the other for reducing the temperature of lean solvent (after exchanging heat with rich solvent) such that the temperature is approximately 5.5o C (10o F) above inlet gas temperature using cooling water are sized (heat transfer area required for both exchangers is calculated). Stripping tower is assumed to operate at 5 kgf/cm2 and 1200 F. Steam circulation rate, tower diameter, weir height, No of real trays required, and shell thickness required for absorption are calculated Part II --- Simulation of acid gas treatment plant using DIPA as a solvent on HYSYS. Natural gas 20.0786 MMSCFD (1000 kg- mole/hr) natural gas flowrate with is pressure of 1000 psia and at a temperature of 109.4o F is considered for sweetening. During the sweetening process H2 S is to be removed from that present in natural gas to tolerable specifications. In the present case H2 S is reduced from an initial composition of 0.09 to 2*10(-6) (mole fraction basis); which is 9 % by mole in sour gas to 2*10(-4) % by mole in the sweet gas. The flow-sheet is developed with all the necessary equipments, PFD developed and the data-sheets generated for all the equipments are given in this report.
No. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. INTRODUCTION
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SULFINOL (Material Property Sheet) LITRATURE SURVEY -- PHYSICAL PROPERTIES OF SOLVENTS METHODOLOGY OF PROCESS SELECTION...