The document outlines a student project to simulate a 20MMSCFD natural gas treating plant using Aspen HYSYS. A team of 4 students is supervised by an internal and external guide. The objectives are to design and simulate the plant in summer and winter cases, and optimize the plant. The document describes the feed gas conditions and compositions, various treating processes to remove impurities like H2S and CO2, simulation of dehydration, cryogenic recovery of NGLs, and results showing no change in LPG production between cases.

1. TEAM MEMBERS
Arun Kumar M(712819139005)
Sitharthan V(712819139024)
Santhosh Kumar A(712819139021)
Seethapathi P(712819139023)
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Natural Gas Processing Plant Simulation using
Aspen HYSYS
EXTERNAL GUIDE
Mr. K. KAMALAHASAN
FERMION ENERGY & ENGINEERING SOLUTION
PRIVATE LIMITED
INTERNAL GUIDE
Dr. B. VIJAYAKUMAR
ASSOCIATE PROFESSOR
DEPARTMENT OF PETROCHEMICAL ENGINEERING
RVSCET

2. OBJECTIVES
• To Design the 20MMSCFD Gas Treating Plant.
• To Perform Simulation in Summer case
• To Perform Optimization of the Gas Treating Plant.
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3. INTRODUCTION.
• Natural Gas produced from the well contains hydrocarbons, Carbon
dioxide, Hydrogen sulfide, and water together with many other
impurities.
• Some of the required processing can be accomplished near the Well
Head.
• Complete Processing of Natural Gas takes place in Processing plant.
• The Objective of this plant is treating Natural Gas and conditioning
them gases for sales and disposal.
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4. ASPEN HYSYS INTRO
• There are many different simulation programs used in industry depending on the
field of application and desired simulation product.
• When used to its full capability ‘ASPEN HYSYS’ can be very powerful tool for an
engineer to achieve major business benefits by
• Ensuring more efficient and profitability design.
• Improving plant control, operability.
• Reducing human error and time requirement.
• The inherent flexibility contributes through its design, combined with the
unparalleled accuracy and robustness provided by it, leads to represent a more
realistic model.
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LITERATURE SURVEY:
S.NO Name of the Journal Name of the Paper Author Publishing Year
1 Research Gate ASPEN-HYSYS
Simulation of Natural Gas
Processing Plant &
Analysis of Different
Operating Parameters
Mohammad Hasibul
Hasan
Sadat Kamal Amit
Md. Ruhul Amin
2015
2 Elsevier Demand projections of
petroleum products and
natural gas in India
Jyoti Parikh
Pallav Purohit
Pallavi Maitra
2005
3 Elsevier Natural Gas Dehydration
Process Simulation and
Optimisation -A Case
Study of Jubilee Field
Solomon Adjei
Marfo
Prince Opoku
Appau
2020
4 Research Gate Optimizing Glycol
Dehydration System for
Maximum Efficiency:
A Case Study of a Gas
Plant in Nigeria
Tesi Arubi
Ugochukwu
Ilozurike Duru
2008

6. MATERIALS AND METHODS:
• Feed : untreated natural gas.
• Feed is a taken from the associated gas well.
• Software used : Aspen Hysys
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7. Flow Diagram of Natural gas Processing Plant.
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8. S.NO TREATING PROCESS METHODS IMPURUTIES REMOVED
1.) Condensate and water removal .
Waste Water
2.) Acid Gas Removal Amine Treating, Benfield
Process, PSA unit, Sulfinol
Process .
Hydrogen Sulfide
Carbon Dioxide
3.) Sulfur Unit Claus Process Elemental Sulfur
4.) Tail Gas Treating Soot Process, Clauspol
Process
Offgases
5.) Dehydration Glycol Unit, PSA Unit Water
6.) Mercury Removal Mol Sieves, Activated
Carbon
Mercury
7.) Nitrogen Rejection Cryogenic Process,
Absorption and Adsorption
Process
Nitrogen Rich Gas
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PROCESS:

9. S.NO TREATING PROCESS METHODS IMPURUTIES REMOVED
8.) NGL Recovery
(Hydrocarbon Dew Pointing Unit)
Turbo Expander and
Demethanizer Absorption
Ethane,
9.) Fractionation Train (LPG Recovery) Dethanizer , Depropanizer ,
Debutanizer
Propane, Butane
10.) Sweetening Unit Merox Prosses , Sulfrex
Prosses , Mol Sieves
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FEED GAS CONDITIONS:
S.NO FEED CONDITION
1.) Pressure 5 Bar
2.) Temperature 35℃
3.) Molar Flow rate 5000kmol/hr

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FEED GAS COMPOSITIONS:
S.NO GAS COMPOSITION MOLE FRACTION
1.) Methane 0.69
2.) Ethane 0.08
3.) Propane 0.05
4.) n-Butane 0.02
5.) i-Butane 0.04
6.) n-pentane 0.08
7.) i-pentane 0.013
8.) Nitrogen 0.078
9.) Water 0.019
10.) Carbon Dioxide 0.002
11.) TriEthylene Glycol 0

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PROCESS DESCRIPTION:
INLET GAS SEPARATION AND COMPRESSION:
• Inlet gas is taken into a two phase separator to separate gas and incoming liquids.
• The separated gas gets compressed in a compressors to a pressure level required for gas
conditioning and LPG Extraction unit.
• The separated liquid is pumped to closed drain vessel via pumps.
HP FLASH SEPARATOR
• Moisture and heavy hydrocarbon in gas stream condenses on increasing the pressure.
• The Compressed gas from the inlet compressor passes through HP flash separator to
remove separated liquid.
• HP Flash separator is a two phase vessel which separates gas and liquid.
PRE FILTER COALESCER.
• The separated liquid is then sent to closed drain vessel for hydrocarbon recoveries
while the gas passes through post compression Filter Coalescer.
• It contains the elements needed to remove lube oil mist.

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MERCURY REMOVAL
• No Mercury removal unit in our simulation.
• The Filtered gas is fed into mercury removal bed.
• The mercury is removed by adsorption reaction.
• Adsorbent used: Activated Carbon adsorbent which is supported by ceramic
balls and separated with the mesh screen.
H2S REMOVAL
• The gas then flows through the H2S removal beds where H2S removed by
adsorption reaction.
• Adsorbent Used: Iron Oxide metal adsorbent.
• The beds are arranged in a Lead/Lag Configuration.

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GAS DEHYDRATION:
• After removing mercury and H2S from the gas, It is fed to a mol sieve bed.
• It is used to remove the moisture content in the feed gas.
• It consists of two bed mole sieve system.
• The system is time cycle controlled to switch between beds.
• At design conditions, one bed is in adsorption while the other bed is in
regeneration.
• During adsorption, the flow direction of the inlet gas is down through the bed
and during regeneration, the flow direction of the inlet gas is up through the
bed.
• The scrubber helps to remove moisture stripped from the bed during
regeneration.

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GAS COOLING AND CHILLER UNIT.
• Temperature for gas at inlet condition has significant influence on recovery of
C3 component in LPG.
• In order to achieve the C3 recovery in LPG, the gas coming out from Gas
Dehydration and Mercury removal unit will be cooled in a Gas Cooler using
chilled water.
CRYOGENIC UNIT:
• The dry gas containing less water, is cooled and partially liquified through a
combination of refrigeration recovery via heat exchanger and turbo expander.
• The cold vapor and liquid streams are fed to the Demethanizer where the ethane
and heavier hydrocarbon are recovered as a liquid from gaseous methane and
lighter inert components.
• This gaseous stream is subsequently reheated, recompressed by the residue gas
compressors.
• The liquid product from the demethanizer is boosted up to the operating
pressure of the debutanizer.

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DEBUTANIZER.
• The Debutanizer system is used to separate LPG and NGL product from
Deethanizer bottom.
• Heat is added at the bottom by using a reboiler.
• The vapor produced and the liquid inside were get into contact to become rich
molecular weight compounds.
• The vapor gets condensed in the reflux condenser, which is a total condenser
and pumped back into the tower via reflux pumps.
• TOP PRODUCT : LPG BOTTOM PRODUCT : NGL.

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SALES GAS:
• Sales gas from the cryogenic unit is compressed from 280 PSIG to 1300 PSIG
via the sales gas compressors.
• Fuel gas is taken off of Sales gas stream before flowing to compressor side of
the Turbo – Expander.
• Excess sales gas flow train has not been considered in the design of the Sales
gas compressor.

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RESULTS AND DISCUSSION

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FEED GAS CONDITIONS: SUMMER
CASE
S.NO FEED CONDITION
1.) Pressure 95KPa
2.) Temperature 60℃
3.) Molar Flow rate 5000kmol/hr

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Output: Summer case
Temperature 60 - ℃
Pressure 1849.65 - KPa
Phase std Gas Flow 1604.38 - STD_M³/d
HC Dew Point -18.77 -10 to -50 ℃
Water Dew Point 0 0 to -10 ℃
Water Content 0.3 Less than 7 lb/MMSCF
LHV Mass Basis 46088.04 44000 to 47000 KJ/Kg
Sales Gas Specifications

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RESULT : SUMMER CASE

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FEED GAS CONDITIONS: WINTER CASE
S.NO FEED CONDITION
1.) Pressure 95 KPa
2.) Temperature 15℃
3.) Molar Flow rate 5000kmol/hr

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Output : Winter Case
Temperature 15 - ℃
Pressure 1849.65 - KPa
Phase std Gas Flow 1604.38 - STD_M³/d
HC Dew Point -18.77 -10 to -50 ℃
Water Dew Point 0 0 to -10 ℃
Water Content 0.3 Less than 7 lb/MMSCF
LHV Mass Basis 46088.04 44000 to 47000 KJ/Kg
Sales Gas Specifications

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RESULT : WINTER CASE

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RESULT
• By comparing both the summer and winter case there is no change in the flow rate
of the LPG Product.
• It is identified that in winter case the water recovery section recovered more water
than in the summer case.
• In both the design cases, the LPG gas specifications is reached.
• The material and energy balance sheets has been prepared.

26. REFERENCES
• Mohammad Hasibul Hasan, Quazi Azizul Hassan, Sadat Kamal Amit, Dr. Md. Ruhul Amin; 2015; Research
Gate ASPEN-HYSYS Simulation of Natural Gas Processing Plant & Analysis of Different Operating
Parameters;
• Jyoti Parikh, Pallav Purohit, Pallavi Maitra; 2005; Elsevier; Demand projections of petroleum products and
natural gas in India;
• Reza Hafezi a, AmirNaser Akhavan b, Saeed Pakseresht, David A. Wood; 2021; Elsevier; Global natural
gas demand to 2025: A learning scenario development Model
• Jyoti Parikh, C.R. Dutta Biswas*, Chandrashekhar Singh, Vivek Singh; 2009; Elsevier; Natural Gas
requirement by fertilizer sector in India;
• S. A. Marfo, P. Opoku Appau, C. Morkli and S. Issah; 2020; Research Gate; Natural Gas Dehydration Process
Simulation and Optimisation -A Case Study of Jubilee Field;
• Optimizing Glycol Dehydration System for Maximum Efficiency: A Case Study of a Gas Plant in Nigeria;
I.M.T. Arubi, SPE, Afrogus Consulting, and U.I. Duru, SPE, Federal University of Technology, Owerri-
Nigeria
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27. • Sukanta Kumar Mondal1*, M. Rakib Uddin1, A. K. Azad; 2023; The Scientific Journal of Koya University;
Simulating Combined Cycle and Gas Turbine Power Plant under Design Condition using Open-Source Software
DWSIM: A Comparative Study.
• Sukanta Kumar Mondal, M. Rakib Uddin, A. K. Azad; Research Gate; 2013; Simulation and Optimization of Natural
Gas Processing Plant.
• Abid Salam Farooqi, Raihan Mahirah Ramli 1, Serene Sow Mun Lock, Noorhidayah Hussein, Muhammad Zubair
Shahid 1and Ahmad Salam Farooqi; 2022; MDPI; Simulation of Natural Gas Treatment for Acid Gas Removal Using
the Ternary Blend of MDEA, AEEA, and NMP.
• Dejan Brkic a, TomaI.Tanaskovic, 2008; Elsiever; Systematic approach to natural gas usage for domestic heating in
urban areas.
• Mohamed S. Gad, Hussien. A. Elmawgoud, Tarek M. Aboul-Fotouh, Masoud A. El-Shafie; 2016; Research Gate; The
Economic Comparison Between Dry Natural Gas and Nitrogen Gas For Stripping Water Vapor From Glycol In The
Gas Dehydration Process.
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THANK YOU

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QUESTIONS