ALL ABOUT NATURAL GAS : DEFINITION,FORMATION,PROPERTIES,COMPOSITION,PHASE BEHAVIOR ,CONDITIONING"DEHYDRATION ,SWETENING" AND FINAL PROCESSING TO END USER PRODUCTS

1. Prepared by // Eng. Ahmed Mohamed Shoman
1

2. Content
• Definitions of Frequently Used Parameters in Natural Gas
Industry.
• Introduction for natural gas.
1. Natural Gas Terminology.
2. Natural Gas Formation.
3. Natural Gas Composition.
4. Natural Gas Properties.
5. Natural Gas Phase Behavior..
• Natural Gas Conditioning.
• Field Separation.
• Gas Sweetening.
• Gas Dehydration.
Sweetening /Dehydration Trouble Shooting (Amine & Glycol Unit).
– Gas is not Sweet
– Amine solution not regenerated
– Dirty, degraded amine
– Excessive Corrosion
– Foaming of amine solution
– Inlet gas temperature too low
– Wrong or off-spec – chemicals
– Misuse or abuse of antifoam chemicals in amine units
– Incoming gas is not adequately scrubbed and contains salt water 2
– Tray down comers are plugged, causing amine to stack up in the trays .

3. Content
• Natural Gas Processing.
 By Refrigerated lean oil Absorption.
 By J.T and LTS.
 By Turbo Expander.
• Examples for Gas Plants
 Ras Shukier Gas Plant . "GUPCo"
 Amreya Gas Plant.
 Port Said NGL Plant.
 The UGD Company.
 Syrian "Dier El-zour " D.Z Gas Plant.
 Ras Shukier NGL Plant "EBGDCO"
• NGL Recovery
– NGL and LPG recovery technology.
– GTL production technologies.
- Separation of NGL 3

4. Content
• Fractionation Towers.
– Types of Fractionation Tower.
– Types of Trays.
– Tray Towers Operation Problems.
– Packing Types
• Sulfur Recovery Unit “SRU”:
– Sulfur content in natural Gas & its Economic Value.
– SRU “ Clause process”
• Natural Gas Compression
•
o Introduction
• o Reciprocating Compressors
• o Centrifugal Compressors
• o Comparison between Compressors
• o Compressor Selection
• o Multistage Compression
• o Compressors Calculations
• o Compressor Performance Maps
4

5. Definitions
1- Associated Gases : Gas associated with liquids.
2- Non associated gases: Gas produced from gas wells without liquids.
3- Dry gas : Natural gas is considered 'dry' when it is
almost pure methane, having most of the other commonly associated
hydrocarbons removed.
4- Wet gas : When other hydrocarbons are present, the
natural gas is 'wet'.
5- Sour gas : Natural gas which contains H2S and CO2
(acid
gases).
6- Sweet gas : natural gas which doesn’t contains H2S and
CO2.
5

6. Definitions
7- Hydrated gas : Natural gas which contains H2O.
8- Dehydrated gas: Natural gas after removal of H2O.
9- LNG : Liquefied natural gas , mainly CH4
10- LPG : Liquefied petroleum gases , “Commercial Propane-
Butane mixture”
11- Condensate : pentanes and heavier , C5+
12- GTL : Gas to liquids.
13- NGL : Natural gas liquids , ethane and heavier.
14- SRU : Sulfer Recovery Unit
6

7. Definitions
15- Acid Gas : Feed stream to sulfur recovery plant consisting H2S, CO2,
H2O, and usually less than 2 mol % hydrocarbons.
16-Claus Process:
The process in which 1⁄3 of the H2S in the acid gas feed is burned to SO2
which is then reacted with the remaining H2S to produce sulfur. This is also
referred to as the modified Claus process. ( H2S + 1⁄2 O2 → S + H2O )
17-Residence Time: the period of time in which a process stream will be
contained within a certain volume or piece of equipment, seconds.
18-Tail Gas Cleanup Unit: a process unit designed to take tail gas from a
Claus sulfur recovery plant and remove additional sulfur with the goal of
meeting environmental sulfur emission standards.
7

8. Introduction:
Natural Gas is a vital component of the world's supply of energy. It is
one of the cleanest, safest, and most useful of all energy sources.
What is Natural Gas:
Natural gas is a combustible mixture of hydrocarbon gases( from CH4
to C8H18”OCTANE) consisting essentially of METHANE ,other
hydrocarbons and non Hydrocarbon Gases in gaseous state ,which is
extracted from the subsurface of the earth in its natural state ,separately or
together with liquid hydrocarbons
8

9. The Formation of Natural Gas:
Natural gas is a fossil fuel like oil and coal.
Fossil fuels are, essentially, the remains of
plants ,animals and microorganisms that
lived millions and millions of years ago.
9

10. Natural Gas Under the Earth:
Although there are several ways that methane,
and thus natural gas, may be formed, it is
usually found underneath the surface of the
earth. As natural gas has a low density, once
formed it will rise towards the surface of the
earth through loose , shale type rock and other
material.
With natural gas trapped under the earth in this
fashion, it can be recovered by drilling a hole
through the impermeable rock. Gas in these
reservoirs is typically under pressure, allowing it
to escape from the reservoir on its own. 10

11. Typical Composition of Natural Gas :
Water
Impurities CO2,H2S, Hg
Nitrogen
Methane
LNG
Ethane
NGL’s Propane
Butane LPG
Pentane
Hexane C5 +
Heptane
Octane
11

12. Typical Composition of Natural Gas :
12

13. Oxygen: Max. ( 0.1% ) by mole.
* Carbon dioxide: Max. ( 3 % ) by mole.
* Hydrogen sulphide: Max. ( 4 ) PPM
* Sulphur: Max. (50 ) mgm / SCM
* H.C. dew point:
Mercury: Max. (6 ) mgm / SCM
* Gross Heating Value : Min. 980 ( +5 ) Deg.C
* Max. 1180 BTU/SCF
* .( zero ) Deg. C at a pressure of ( 70 ) kg /cm2 gauge
Water dew point : Max. ( 1 ) PPM or below
13

14. Natural Gas Properties
14

15. Ideal Gas Law
PV =
Where :
nRT
P : Absolute pressure
V : Volume
T : Absolute temperature
R : Universal gas constant
n : Number of moles n = m / M
m : Mass of the gas
M: Molecular weight
The ideal gas law can be expressed as :
PV = (m/M) RT
m = MPV/RT
m/V = ρ = MP/RT ρ is density of gas 15

16. Behavior of Real Gases
PV = ZnRT
Where :
Z is deviation or compressibility factor and can be expressed as
Z = [ actual volume of n moles of gas / (ideal volume of n moles of gas
at certain P & T) at same P & T ]
where Z is dimensionless.
16

17. Properties of Gaseous Mixtures
Composition of natural gas may be expressed as either mole fraction, volume
fraction or weight fraction.
Mole Fraction yi = ni/∑ni
where:
yi : Mole fraction of component i
ni : Number of moles of component i
∑ni : Total number of moles of all components in the mixtures
Volume fraction vi = vi/∑vi
Weight Fraction w i =Wi/∑Wi
17

18. Determination of Z Factor
From the next chart after determination of Pr and Tr we can determine Z factor
Pr = P / P c Tr
Tr = T / T c
Z
Where :
Pc= ∑Pci*Yi
Tc= ∑Tci*Yi
Pr 18

19. Natural Gas Phase Behavior
 The natural gas phase behavior is a plot of pressure vs temperature that
determines whether the natural gas stream at a given pressure and
temperature consists of a single gas phase or two phases: gas and liquid.
The phase behavior for natural gas with a given composition is typically
displayed on a phase diagram, an example of which is shown in Figure 1-1.
 The left-hand side of the curve is the bubble point line and divides the
single phase liquid region from the two-phase gas–liquid region.
The right-hand side of the curve is the dew point line and divides the two-
phase gas–liquid region and the single-phase gas region.
19

20. 20

21. :At point X
Xi=xy/zy Retrograde region
id
Yi=xz/zy liq u
z Gas
x y
21

22. Definitions
Phase Diagram-1
A record of the effects of temperature, pressure and composition on the kinds and
.numbers of phases that can exist in equilibrium with each other
Bubble Point-2
The point at which the first small vapour bubble appears in a liquid system. The
.bubble point curve on a phase diagram represents 0% vapour
Dew Point-3
The point at which the first infinitesimally small droplet of condensation forms in a
gaseous system. The dew point curve on a phase diagram represents 0%
.liquid
Phase Envelope-4
The area on a pressure-temperature phase diagram for a mixture enclosed by the
bubble and dew point curves. This area represents the set of conditions for the
. mixture were vapour and liquid phases co-exist in equilibrium
)Cricondenbar (Pmax-5
.The maximum pressure at which vapour and liquid can co-exist in equilibrium
22

23. Definitions
6-Cricondentherm (Tmax)
.The maximum temperature at which vapour and liquid can co-exist in equilibrium
Critical Pressure-7
.The vapour pressure at critical temp
8-Critical Temperature
The temp. above which all the mixture cannot be liquid
Quality Lines-9
Lines through the two-phase region showing a constant percentage of liquid and
.vapour
10-Retrograde
The name given to phase behaviour above the critical temperature and pressure
were vapour and liquid phases coexist and the amount of vaporisation or
condensation changes with pressure and temperature in the opposite
direction to normal behaviour. (e.g:condensation of liquids occur by lowering
pressure or increasing temperature)
23

24. Definitions
11-Equation of State (e.g : ideal gas law)
An equation which describes the relationship between pressure,
temperature and molar volume of any homogenous fluid at equilibrium
12- Critical Point
The point on the phase diagram where The bubble point and dew point lines
intersect , where the distinction between gas and liquid properties disappears.
The natural gas phase behavior is a function of the composition of the
gas mixture and is strongly influenced by the concentration of the
heavier hydrocarbons, especially C+ . The presence of heavier
hydrocarbons will increase the phase envelope and failure to include
them in a phase calculation will under predict the phase envelope.
:As shown by the next exmple
24

25. 25

26. 26

27. 2500
( TSCF ) 36.2 %
2000
3.1 %
4.9 % 36.1 %
1500
7.2 %
1000
4.6 %
500 7.9 %
0
N-America S-America Europe Africa Mid-East Sov- Asia/Austr.
Countries
27

28. Fertilizer
Methane: /Methanol/Olefin / GTL
Feedstock
Ethane : Petrochemical Feedstock.
Petrochemical Feedstock
Propane: or Fuel.
NATURAL
Refinery Feedstock /
GAS I-Butane: Fuel.
Gasoline Blending / Fuel
N-Butane: / Petrochemical
Feedstock.
Natural Gasoline
(IC5+)
Refinery Feedstock or
Petrochemical Feedstock.
Condensate
28

29. Separation between the Oil &Gas
Sweetening remove the Acid Gases
Conditioning Dehydration remove the Water vapour
Main Target H.C Dew Point & Heating Value
-Extract main component into
separate products which are
)Extraction (Processing Methane
Main Target Ethane
Propone
LPG
Natural Gasoline 29

30. 30

31. Training Videos
I- Natural Gas Processing Principles
30
31

33. Gas Conditioning
• Field Separation.
• Gas Sweetening.
• Gas Dehydration.
33

34. • Large Vessels are used to
separate the gas, oil, water and
sand using their different
densities.
• Sufficient time has to be given to HP Gas LP Gas
allow the water droplets to settle
from the oil and vice versa.
HP Separator LC LP Separator
• Multiple stages are used to
LC
liberate gas and remove water. Heating/ Heating/
Cooling Cooling
• The number of stages is assessed
Water
balancing cost, energy efficiency,
effect on the reservoir and safety.
Export
• The separation process may Dehydration/
Cooling
require heating to help destabilise Desalter
LC
Pump
oil-water emulsions.
• Chemicals are utilised to assist
droplet coalescence, break foams Water
and prevent corrosion.
• To prevent remixing and effective
separation the separator is fitted 34
with a range of devices.

35. Separator Internals
• Internals design is often key
to efficient separator
operation.
– Inlet device to reduce
liquid momentum
(centrifugal/impingeme
nt)
– Distributor plate
– Coalesce pack to
provide surface area
for small droplets to
coalesce to larger
ones, enhancing
liquid/liquid separation
– Vane packs or
demisters to collect oil
droplets from the gas
– Vortex breakers to
prevent gas underflow
– Sand jets to remove
sand from the 35
separator

36. Separator Internals
Baffle Plate Set Inlet Diffuser & Cascade Tray
Cyclone Inlet Device
Cyclone Inlet Device Foam Reducing Pack Assembly
with 36
Perforated Baffle Plate

37. Separators Types
• Separator features :
• Horizontal Separators – Primary separation section to
– Large liquid handling separate the bulk of the liquid from
the gas
capacity
– Sufficient capacity to handle liquid
– Sufficient time for settle out surges
of liquid droplets from the – Sufficient liquid residence time to
allow small droplets to settle out
gas
– Some inlet device to reduce
• Vertical Separators turbulence and velocity in the main
separation section
(scrubbers)
– A mist extractor to capture entrained
– High gas volumes droplets
– Small footprint area – Back pressure and liquid level
controls 37
– Relief and blowdown

38. Training Videos
II- Natural Gas Separators Principles
30
38

39. 39
Day#2

40. •Sweetening process is to remove acid gases from natural gases.
•This can be done either by adsorption or absorption processes.
•The most famous adsorption process is solid desiccant beds which can
perform Sweetening and dehydration for natural gas at the same time with
higher efficiency.
•The most famous absorption process is amine.
40

41. AMINE PROCESS
41

42. CHEMICAL ABSORPTION
H H
-HO-C - C
H H
42

43. 43

44. Ty
pic
al
44

45. 45

46. FIG. 21-5
Physical Properties of Gas Treating Chemicals
”“weak bases
Mono- Di- Tri-
Property Ethanolamine Ethanolamine Ethanolamine
Formula HOC2H4NH2 HOC2H4)2NH) HOC2H4)3N)
Molecular Wt 61.08 105.14 148.19
Boiling point @ 170.5 269 (decompose )360
760 mm Hg, °C
Density @ 20°C, 1018 1095 1124
.kg/m3
46

47. A brief review of the more frequent problems and corrective •
: procedures follow
1- Gas is Not “ Sweet “/Dehydrated
:Check solution concentration
– Too low : Check make up water addition.
:Check amine flow rate
– Too low : Open by pass valve.
:Check amine regeneration
– Increase firing rate.
:Check reflux rate and temperature
– Probably too low : Increase firing rate.
:Check stripping column pressure
– It may be too low
: Check for foaming
– Carry over into outlet separator and / or pressure fluctuations across
absorber.
47

48. 2- Amine solution not regenerated
• Check reboiler temperature ,pressure and the
reflux rate.
• Check for leaks in lean/rich amine heat
exchanger.
• Check the re-claimer for primary amine.
• Check for foaming in stripper :
- pressure fluctuations.
48

49. 3- Dirty, degraded amine
• Gas contains oxygen.
• Storage or make up tank blanket gas valve is
not functioning: - Repair if any.
• Make up water contains free oxygen:
- Add oxygen scavenger or use distillated
water.
• Sparge amine with sweet gas to strip oxygen.
49

50. 4- Excessive Corrosion
Amine concentration is too high:
 Add make up water .
Amine is highly degraded:
 Replace .
Make up water is high in dissolved solids :
 Treat make up water or use deionized water.
Insufficient amine regeneration:
Insufficient amine filtration :
 Increase filter rate or change filter elements more frequently.
Qxygen is entering system:
 Eliminate.
Velocities too high :
 reduce temperature to stripper.
50

51. 5- Foaming of amine solution
• Foaming is a very unpredictable phenomenon.
It can be caused by any or a combination of the
following conditions:
 Dirty amine (solids) – check filter elements.
 Degraded amine.
 Liquid hydrocarbon in gas or amine.
51

52. 6- Hydrocarbon condensation
• It will be caused by lower inlet amine
temperature.
• So the Inlet amine temperature must be at
least 10-15 oF above the inlet gas temperature
to eliminate H.C condensation .
52

53. 7- Wrong or off-spec –
chemicals
• Well treating chemicals.
• Surfactants.
• Corrosion inhibitors.
• Very fine particles. e.g. iron sulfide, in sour gas.
• Inadequate cleaning of amine plant before
start-up.
53

54. 9- Incoming gas is not adequately
scrubbed and contains salt water
• Make up water contains iron, sulfides,
chlorides, etc…
(Use deionized or de-mineralized water)
54

55. 10- Tray down comers are plugged,
causing amine to stack up in the trays
• (This is really not a foaming problem but
behaves so; usually with older plants).
• Note :
 Always add antifoaming downstream of the
carbon filter.
 The following antifoaming are recommended
Dilute with 50% isopropyl alcohol use in
concentrations of 5 to 50 PPMW .
55

56. Training Videos
”II- Gas Sweetening “Amine Uint
18
56

57. AMINE UNIT CASE STUDY
Gupco U104 amine unit
7
ge
Pa
COS “Carbonyl sulfide” it is a colorless flammable gas with an unpleasant odor. It
is a linear molecule consisting of a carbonyl group double bonded to a sulfur atom
it decomposes to H2S & Co2 in presence of humidity and bases
57

58. Day#3
•Dehydration process is to remove water vapor from natural gases.
•This can be done either by adsorption or absorption processes.
• )gas 2 solid( )gas 2 liquid(
• The most famous adsorption process is solid desiccant beds which can
perform Sweetening & Dehydration for natural gas at the same time with
higher efficiency according to its material affinity and pour size .
• The most famous absorption process is Glycol unit.
Water in NG :
 Most free associated water removed by simple extraction method at
or near wellhead
 Water vapor in NG solution need more complex treatment
 Process of dehydration of NG – absorption or adsorption
 Pipeline specs: 7.0 lb H2O/MMSCF { max. =1 ppmv}
58

59. Water Removal
 Absorption “Glycol Dehydration”:
 Glycol solution (high affinity to water) – diethylene glycol
(DEG) or triethylene Glycol (TEG)
 TEG/DEG contact wet gas stream (called contactor) 
absorb water  glycol soln. sink to bottom  removed
 Glycol recovery – vaporize glycol using special boiler
 New tech: addition of flash tank separator condensers
before boiler to condense methane (90 – 99% recovery)
59

60.  Solid-Desiccant Dehydration : “Adsorption”
 Adsorption process consists of 2 or more adsorption tower
filled with solid desiccant.
 At least 1 working, 1 regenerating
 Desiccants: activated alumina or granular silica gel
 Wet NG  pass through towers from top to bottom  H2O
retains on particle surface  dry NG exits  saturated
desiccant heated with heater to vaporize water
 Best suite for large volumes gas under very high P
60

61. 61

62. HYDRATES IN NATURAL GAS SYSTEMS
• A hydrate is a physical combination of water and other small molecules
to produce a solid which has an “ice-like” appearance but possesses a
different structure than ice. , it cause flow interrupting.
• There are three recognized crystalline structures I,II,H
• Their formation in gas and/or NGL systems can plug pipelines,
equipment, and instruments, restricting or for such hydrates. In both,
water molecules build the lattice and hydrocarbons, nitrogen, CO2 and
H2S occupy the cavities.
62

63. • HYDRATES IN NATURAL GAS SYSTEMS
• Smaller molecules (CH4, C2H6, CO2, H2S) stabilize a
body-centered cubic called Structure I.
• Larger molecules (C3H8, i-C4H10, n - C4H10) form a
diamond-lattice called Structure II.
• Normal paraffin molecules larger than n-C4H10 do not
form Structure I and II hydrates as they are too large to
stabilize the lattice.
However, some iso paraffins and cyclo –alkanes larger than
pentane are known to form Structure H hydrates.
63

64. 64

65. Hydrocarbons )C1,C2,C3,iC4+nC4(
and / or H2S, N2, CO2
+
Metastable H20
@
)P, T(
------------------------------------------
=
HYDRATES
Metastable water is liquid water which, at equilibrium, will
exist as a hydrate 65

66. The conditions which affect hydrate formation are:
1- Primary Considerations
• Gas or liquid must be at or below its water dew point or saturation condition.
To allow water droplet condensation
• Temperature.
• Pressure.
•Composition.
2- Secondary Considerations
• Mixing.
• Kinetics
• Physical site for crystal formation such as a pipe elbow, orifice, thermowell, or line
scale.
• Salinity.
66

67. FIG. 20-4 Water Content of Hydrocarbon Gas
P
hydrate
formation line ,
function of
composition
Th 67

68. Hydrate Inhibition
•The formation of hydrates can be prevented by dehydrating the gas or
liquid to eliminate the formation of a condensed water )liquid or solid(
phase.
• In some cases, however, dehydration may not be practical or
economically feasible.
• In these cases, chemical inhibition can be an effective method of
preventing hydrate formation.
• Chemical inhibition utilizes injection of thermodynamic inhibitors or low
dosage hydrate inhibitors (LDHIs).
•Thermodynamic inhibitors are the traditional inhibitors )i.e., one of the
glycols or methanol(, which lower the temperature of hydrate diminish
formation “Th”
•LDHIs are either kinetic hydrate inhibitors (KHIs) or anti -
agglomerants (AAs).
• They do not lower the temperature of hydrate formation, but do its
effect. 68

70. Natural Gas Dehydration
by: Liquid & Solid Desiccants
70

71. 71

72. 72

73. 73

74. 74

75. 75

76. 76

77. 77

78. 78

79. Day #3
Glycol Dehydration Unit
79

80. 80

81. GLYCOLS PHYSICAL PROPERTIES
Ethylene Glycol Di-ethylene Tri-ethylene Tetraethylene
HO—)CH2(2—OH Glycol Glycol Glycol
Formula C2H6O2 C4H10O3 C6H14O4 C6H18O5
Molecular weight 62.1 106.1 150.2 194.2
Boiling point at 760 mm Hg, °F 387.1 472.6 545.9 597.2
Boiling point at 760 mm Hg, °C 197.3 244.8 285.5 314
Vapor pressure at 77°F (25°C) mm Hg 0.12 0.002 0.0004 0.00005
Vapor pressure at 140°F (60°C) mm Hg 1.5 0.08 0.025 < 0.01
Density (g/cc) at 77°F (25°C) 1.110 1.113 1.119 1.120
Density (g/cc) at 140°F (60°C) 1.085 1.088 1.092 1.092
Density (Kg/m3 ) at 77°F (25°C) 1110 1113 1119 1120
Freezing point, °C -13 -8 -7 -5.5
Pour point, °C - -54 -58 -41
Viscosity in centipoise at 77°F (25°C) 16.5 28.2 37.3 44.6
Viscosity in centipoise at 140°F (60°C) 4.68 6.99 8.77 10.2
Surface tension at 77°F (25°C), dynes/cm 47 44 45 45
Specific heat at 77°F (25°C), kJ/(kg.K) 2.43 2.30 2.22 2.18
Flash point, °C (PMCC) 116 124 177 204
Fire point, °C (C.O.C.) 118 143 166 191
Initial decomposition temperature °C 165 164 207 238
81

82. Training Videos
”III- Gas Dehydration “Glycol Unit
15min
10 82
.min

83. 83

84. GLYCOL DEHYDRATION UNIT
84

85. 85

86. 86

87. DEA : 2-6 M3/100 LIT
87

88. 88

89. 89

90. 90

91. 91

92. 92

93. C’99
’195
C
93

94. 94

95. 95

96. 96

97. Training Videos
IV- Gas Dehydration “Principles of Glycol
”Unit
15min
97

98. Solid Adsorpant Dehydration Unit
98

99. 99

100. 100

101. Molecular Sieves Adsorber / Internal
Arrangement
101

102. GAS DEHYDRATION / Molecular sieves
102

103. GAS DEHYDRATION / Molecular sieves
103

104. GAS DEHYDRATION / Molecular sieves
104

105. GAS DEHYDRATION /
Molecular sieves
105

106. GAS DEHYDRATION / Molecular sieves
106

107. GAS DEHYDRATION / Molecular sieves
107

108. GAS DEHYDRATION / Molecular sieves
108

109. FV-4004
RDV MDV RDV MDV RDV MDV
4-E3 4007 4001 4009 4003 4011 4005
GUPCO U-104 G/P
FV-4003
Dryers Scheme
4-D1C
2FV-4020
4-D1A
4-D1B
4-V43
4-C1A/B
PH-I
FV-4005
2FV-4011
Amine
Unit
RDV MDV RDV MDV RDV MDV
4008 4002 4010 4004 4012 4006
FV-4006
4-F17 4-C3A/B
Tie-in
4-V15
FV-4007 2FV-4013
2FV-4019
FV-4002
BDV-4001
4-C5A/B
FV-4001
2FV-4014
2FV-4012
2RDV 2MDV 2RDV 2MDV 2RDV 2MDV
Tie-in
4007 4001 4009 4003 4011 4005
2FV-4015
ESD-1908
2FV-4017
4-V143
4-D101C
4-D101A
4-D101B
4-C103A/B
4-C101A/B
PH-II
4-F217 ESD-1907
4-H1D
2FV-4018
2FV-4016
2RDV 2MDV 2RDV 2MDV 2RDV 2MDV
4008 4002 4010 4004 4012 4006
109
4-F117
Pg.9 Of 10 P. Eng. / A.Z

110. 1” Ceramic Ball ( 52 CF )
Upper Screen
( 20 Piece )
6”
Molecular Sieve Charge
( 80,200 lb )
Dimensions:
144” I.D
20’ S/S
1/8” Ceramic Ball ( 26 CF )
1/4” Ceramic Ball ( 26 CF )
3”
3”
Lower Screen
4-D1A/B/C Dimensions
110
10 Of 10 P. Eng. / A.Z

111. Table 1
Molecular Sieve Operation Chart
Process Step 1 2 3 4 5 6
D1A-4 D D D H C D
D1B-4 D H C D D D
D1C-4 C D D D D H
D101A-4 D D D D H C
D101B-4 D D H C D D
D101C-4 H C D D D D
FV-4003, 2FV-4015, 2FV4018,
2FV-4020 Open Close Open Close Open Close
FV-4004, 2FV-4016, 2FV4017,
2FV-4019 Close Open Close Open Close Open
111

113. DAY# 4
113

114. 1. By lean oil absorption
2. By Refrigeration & LTS.
3. By Cryogenic Process
114

115. 115

116. Compressor
Sales . Gas Flare
Sales . Gas
Feed
Dry . Gas
LTS
Wet . Gas Exchanger
Inlet
Separator Dehydration
Stabilzer
Water
.Cond
F.G
Cooler
To. Stabilizer
116

117. Cryogenics : Is the study of the production of very low temperature materials
(below −43°C) and the behavior of materials at those temperatures.
117

118.  Process Units
 Deethanizer – separates ethane from NGL stream
 Depropanizer – separates propane
 Debutanizer – boils off butanes leaving pentanes and
heavier HC in NGL stream
 Butane splitter (Desiobutanizer) – separates iso and n
butanes
Component BP oF at 1 atm
Ethane -127 (-88 oC)
Propane -44 (-42) oC
Iso-butane 11 (-11 oC)
n-butane 31 (-0.5 oC)
Pentane 97 (36oC) 118

119. Turbo Expanders
• The use of turbo expanders in gas processing plants began in the early sixties.
• By 1970, most new gas processing plants for ethane or propane recovery were
being designed to incorporate the particular advantages characteristic of an
expander Producing usable work.
• The trend in the gas processing industry continues toward increased use of the
turbo expander.
• Selection of a turbo expander process cycle is indicated when one or more of the
following conditions exist:
 “Free” pressure drop in the gas stream.
 Lean gas.
 High ethane recovery requirements (i.e., over 30% ethane recovery).
 Compact plant layout requirement.
 High utility costs.
119
 Flexibility of operation (i.e:easily adapted to wide variation in pressure and products).

120. Turbo expanders
120

121. • This figure represents the pressure- Turbo expanders
temperature diagram for this expander
process.
• The solid curve represents the plant
inlet gas & the dashed one represent
expander inlet gas (less in heavy H.C)
• At a fixed pressure and, if the
temperature of the gas is to the right of
this dew point line, the gas is 100
percent vapor.
• If the gas is cooled, liquid starts to
condense when the temperature
reaches the dew point line.
• As cooling continues, more liquid is
condensed until the bubble point line is
reached — the solid line on the left.
At this point, all of the gas is liquid.
121
Additional cooling results in colder liquid

122. Turbo expanders
• A turbo expander recovers useful work from the expansion of a gas stream.
• The process operates Isentropically in the ideal case and produces something
less than the theoretical work in the real case.
• In the process of producing work, the expander lowers the bulk stream
temperature which can result in partial liquefaction of the bulk stream.
122

123. To Sales Gas
Compressor
Re Expander
comp
3 4
Feed
Gas Lts
Jt
Valve
11
Dehydration
Pkg
Q-1
7
De-Methaniser To De-
De-Propaniser Ethaniser
De-Butans
123

124. "”Mixed Refrigerant Processes
Mixed Refrigerant Processes are used through LNG/NGL plants to
avail sub-cooling for natural gas where a single mixed refrigerant is used
(composed of nitrogen, methane,ethane, propane, butane and pentane).
The refrigerant is designed so that the refrigerant boiling curve nearly
matches the cooling curve of the gas being liquefied. The closeness of
the match of these two curves is a direct measure of the efficiency of the
process.
124

125. “Cold box exchangers”
The cold box is a series of aluminum plate fin exchangers which provide
very close temperature approaches between the respective process streams.
The low pressure refrigerant is compressed and condensed
against air or water in a closed system. The refrigerant is not totally
condensed before being sent to the cold box. The high pressure
vapor and liquid refrigerant streams are combined and condensed
in the main exchanger.
The condensed stream is flashed across a J-T valve and this low
pressure refrigerant provides the refrigeration for both the feed gas
and the high pressure refrigerant.
125
,see fig 16-31 GPSA sec.16 in which

126. Training Videos
IIV- Cryogenic Principles
15min
126

127. Examples for LPG,NGL and
LNG Gas Plants
127

128. Boosting & Sales Gas
Comp.
Send sales 4-W4A
gas to GASCO
net ( 64-100) kg/cm2
Chilling Area PH-I
LPG
4-W1A
4-C3A 4-W4B
4-T1
Drying Area PH-I
4-T2
4-D1C
4-D1A
4-D1B
4-W4C
4-C3B
4-W1B 4-W105
COND.
Fractionation Area
- Produce LPG & Condensate
Chilling Area PH-II
LPG 4-W104A
4-W101A
4-C103A Sales Gas
Drying Area PH-II
Utilities
4-D101A
4-T101
4-T102
4-D101B
4-D101C
- Inst. Air System
4-W104B - Heating Oil System
- Refrigeration
4-W101B Package
4-C103B - Cooling Water
Compression System
Area - Power House
-Compress gas COND. - Fuel Gas System
press from 6-47 - Multi-Nozzle Flare
kg/cm . Expansion & Chilling System
Area - Nitrogen Unit
- pre-separation - Loading Area
for heavy H.C Separate Heavy H.C by
cooling down to -60 ‘c 128
-Storage Area
-LPG Berth # 4

129. N.G ( 1043
Demethanizer MMSCFD )
26.3 Bar Depropanizer
Packed Tower Condenser
-76 °C 25.6 Bar Condenser
Bubble cap
-43 °C ( 30 Tray ) M
Packed Tower 18 Bar
26.6 Bar 27.3 Bar 50.7 °C
-74.4 °C -31.7 °C
-74.5 °C C3 Expert
27.3 Bar ( 925 T/D )
-74.4 °C
Demethanizier
26.6 Bar
Depropanizer
Absorber
-68 °C
-33 °C
Sales Gas -36 °C
1043 20 Bar
( MMSCFD ) 31 Bar -78.2
50 °C °C
Propane T/D 925 10-E-04
-69.5 °C 30-E-01
LPG T/D 1215 LPG Local
Turbo
20 Bar Market
Compressor Expander
Condensate T/D 348 78.2 °C LPG Rundown
1215 T/D
Cools M
13.5 Bar
50 °C
Plat Fin
25.6 Bar
Dehydration -43 °C
Debutanizer
Package
1100 66 Bar
MMSCFD Inlet Filter Mercury 40 °C 64.7 Bar 64.7 Bar
70 Bar Separator Removal -24 °C -35 °C
Plat Fin
30 °C 10.2 Bar
62 °C 1.85 Bar
-58 °C
120.8 °C
28.3 Bar Separator 28.2 Bar
28.5 Bar 30 –E -02
-50.9 °C -69.5 °C -36 °C
-33 °C M
12910.2 °C
50
Bar
DNG Rundoum Cools
Condensate ( Local Market )
( 348 T/D )

130. 130

131. Regeneration Gas Compressors
C-111/112
Regeneration Gas Cooler
A-311
Feed U-104
PCV-410
Dehydration Dust Filter
F- 416/417
Regeneration Gas Scrubber
Dust Filter F-451 V-418
Dehydration Gas Scrubber Mercury Removal Bed Dehydration inlet
V-410 V-450 Filter Coalescer
Dehydration Adsorbers Regeneration Gas Heater Residue Gas To Pipeline
F-412
V-413/414/415 E-211
Cold Gas Reflux Exchanger
E-222
Exp/Comp Discharge Cooler
A-321
Depropanizer Reflux Condenser
A-341
C-121/122
Deethanizer Reflux Acc.
V-422
Depropanizer Reflux Drum
V-441
Depropanizer Deethanizer
T-541 V-521 P-621/622/623 JT Warm Gas/Gas Exchanger
E-221
Depropanizer Reflux Pumps
P-641/642
Propane To Storage Cold Separator Deethanizer Side Reboiler
V-421 E-224
Depropanizer Reboiler
E-241
Deethanizer Bottom Reboiler
Butane to Storage E-225
Feed P-695/696 Booster P-693/694

132. EXAMPLES FOR NGL GAS PLANTS
DOVE ENERGY-YEMEN PLANT
15min
132

133. NGL Extraction
Typical Product Recoveries
( % ):
Plant Type Turbo- Joule Lean Oil Refrigera
-> Expander Thompson tion
Product
Ethane 60 – 96% 45 – 60% 25 – 45% 1 – 5%
C2
Propane 90 – 98% 85 – 95% 80 – 95% 20 – 40%
C3
Iso-Butane 96 – 100% 96 – 100% 93 – 99% 40 – 60%
IC4
N.Butane 97 – 100% 97 – 100% 94 – 99% 40 – 60%
NC4
•NGL Recovery
133

134. Distillation or Fractionation
Towers
and Tray Troubleshooting
134

135. Fractionation Towers
• There are two main types of Fractionation Towers according to its
inside configuration :
• 1- Trays Towers .
• 2- Packed Towers.
• Here below we will concentrate on Trays one as for its widely
usage all over the world .
135

136. Trays Towers
TRAY TYPS :Flow Regime
136

137. TRAY TYPS :Perforation Regime
137

138. TRAY TYPS :Perforation Regime
138

139. 139

140. 140

141. 141

142. Tray Towers Problem
142

143. Tray Towers Problem
1
143

144. Tray Towers Problem
2
144

145. Tray Towers Problem
3
145

146. Tray Towers Problem
4
146

147. Packing Types
147

148. 148

149. BOOSTER STATION UTILITIES
149

150. FT
’’FM-Ashrafi 20
’’20
’’FM-Hilal 20
PV-321
PI 4.7 Kg/cm2.g
TI 34 C To Flare
U-102 SLUG CATCHER
.GAS COMP
C1A-2
.GAS COMP PI 19-26 Kg/cm2.g
FT C1B-2 TI 50 C
Glycol
PCV-308
.Unit ESDV FT
TO U-104
New
.GAS COMP Glycol
C1C-2 Unit ved
mo
d y re ’’16
lrea
re a
ls we
.GAS COMP
te rna
C1D-2
e s in ’’4
alv
ckv
che Fuel To Unit
’’8 ’’8
Closed
)suco pipe line’’ ( 12
Pig receiver
Process Div

152. BOOSTER STATION UTILITIES
* Utilities :
-Gas compressor
-Heat Exchanger
- Inst. Air System
- Refrigeration Package
- Cooling Water System
- Power House
- Fuel Gas System
- Flare System
- Nitrogen Unit
- Storage Area
152

153. Natural Gas
Compression

154. Purposes of gas compression
Theory of gas compression
Main types of compressors
Centrifugal Compressor
Reciprocating Compressor

155. Purposes of Gas
Compression
For transportation facilities.
For extra processing (liquefaction, dehydration & sweetening).

156. Theory of Gas
Compression
PV = ZnRT = Z (m/M)RT
P1V1/T1 = P2V2/T2

157. Main Types of Compressors
1- Dynamic type (Centrifugal) P1
T1
V1
Construction:
P2 T 2 V 2
1- Rotor
− − − −
−
+ +
+ +
+
2- Stator

158. Anti-surge Control

159. 2-Reciprocating Compressor:
Stroke
Compression chamber
Piston
Each cylinder consists of :
Piston
Chemise
Inlet valve
Outlet valve

160. Comparison of reciprocating & centrifugal compressors

162. HEAT EXCHANGERS
15min
15min
vedio presentation
162

163. N2 UNIT
N2 unit PFD
CW in Potable water
Fuel Gas
Plate H.E
Combustion chamber Cooling pumps
CW out
Exhausts Comp.
Air intake
filter
CW in
After cooler
Co2&H2O
Absorber
CW out
Cond. Water
OD
tape
Air Blower N2 Reservoir
OD Design
To plant utilities 90 psig
80fo
air
Fuel gas
Exhaust
N2 OD
Cooling water
163

164. U-102
Hilal 4” FUEL PIC-307 PIC -316A
GAS
PIC -316B
V21-2
LV-716
V6-2
0
LV-710

168. Course Final quiz
• 1// What is Natural Gas , definition , composition ,formation and uses?
• 2// What the sections and devices of horizontal separators ?
• 3// What does this Appreciations' mean?
– LNG - SRU
– NGL - Acid Gas and tail gas
– P&ID
– PFD
– LTS
– Dew Point Depression .
• 4// What is the difference between the:
• Absorption and Adsorption Process ? Give examples!
• Hazard and Risk
• 5// what is the recommended temp. difference between Gas & Liquid desiccant
interring to a contactor tower ?
• 6// What are the Filter Types used at the TEG and DEA units ? (and purpose of
every type)
• 7// draw a schematic drawing for a TEG typical Dehydration Unit ?
• 8// What are the main four types of gas cryogenic process ?
• 9// what are the Towers ‘ performance constraints & main cause of every
constraints ?
• 10// what are the rout parameters affect LPG Specifications at the
Fractionation Area ?
168
------------------------------------------------------------------------------

169. 11// why the TEG is widely used at Glycol Dehydration?
12// what the recommended temp./pressure for TEG still reboiler ?
13// What are the booster station utilities ?
14// what is the main types of compressors ? Advantages and disadvantages?
15// what are the main types of heat exchangers ? Give exapmles of H.
Exchangers at your plant ?
16// what are the two types of air coolers ?
17// what is the solid disicants used at your plants?
------------------------------------------------------------------------------
169

170. 11// what are the main reactions take place at SRU?
12//what meant by sulfer recovery ? Feeds,products,recovery, components….
13// what are the operating parameters of SRU?
14// what are the precautions before the SRU start up?
15//what is the source of SRU acid gas ?
16// why we treatment the tail gas?TGT?
17//what is the purpose of sulferpit degassing system? how does it work?
18// what is the blanket gas system, give example?
19//The 1/5 of h2s will be nurned out in the thermal claus reactor?
20//what are the waste heat recovery unit?
21//steam boiler in SRU? tell how & why !
------------------------------------------------------------------------------
170

171. THANKS ,,,
Eng. Ahmed Shoman
Natural Gas Processing Engineer
GUPCO "Gulf of Suez Petroleum Co."
Mobile: +2-0122-743-2850 , +2-0100-800-4930
e-mail:
shomanAM@gupco.net / shomanNMC@yahoo.com
171