IGS-M-CH-050(0)
March 2012
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N.I.G.C. March 2012 IGS-M-CH-050(0)
This standard is intended to be mainly used by NIGC and contractors and has been prepared on interpretation recognized standards, technical documents, knowledge, backgrounds and experiences in gas industries at national and international levels.
Iranian gas standards (IGS) are prepared, reviewed and amended by technical standard committees within NIGC Standardization division and submitted to the NIGC's "STANDARDS COUNCIL" for approval.
IGS Standards are subject to revision, amendment or withdrawal, if required, thus the latest edition of IGS shall be checked/inquired by NIGC users.
This standard must not be modified or altered by the end users within NIGC and her contractors. Any deviation from normative references and/or well known manufacturers specifications must be reported to Standardization division.
Any comments from concerned parties on NIGC distributed IGS are welcome to technical standards committees and will receive serious attention and consideration should a revision to standards is recommended.
GENERAL DEFINITIONS:
Throughout this standard the following definitions, where applicable, should be followed:
1- "STANDARDIZATION DIV." has been organized to deal with all aspects of industrial standards in NIGC. Therefore, all queries for clarification or amendments are requested to be directed to mentioned division.
2- "COMPANY": refers to national Iranian gas company.
3- "SUPPLIER": refers to a firm who will supply the service, equipment or material to IGS specification whether as the prime producer or manufacturer or a trading firm.
4- "SHALL ": is used where a provision is mandatory.
5- "SHOULD": is used where a provision is advised only.
6- "MAY": is used where a provision is completely discretionary.
-------------------------------------
Website: http://igs.nigc.ir
E-mail: igs@nigc.ir

N.I.G.C. March 2012 IGS-M-CH-050(0)
TABLE OF CONTENT
1. SCOPE
2. REFERENCES
3. DEFINITION
4. REQUIREMENTS
5. INSPECTION
6. MARKING
7. PACKAGING
8. STORAGE LIFE
9. DOCUMENTATION
ANNEX A – Data Sheet for MDEA
ANNEX B – Data Sheet for aMDEA
ANNEX C – Questionnaire for aMDEA Evaluation
(Informative)
ANNEX D – Typical Purity and Physical Properties of aMDEA (Informative)
4
5
5
6
1
1
2
2
6
7
8
9
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N.I.G.C. March 2012 IGS-M-CH-050(0)
1. SCOPE
This standard specification covers the minimum requirements for methyldiethanolamine (MDEA) and activated methyldiethanolamine (aMDEA) for absorbing H
2
S and CO
2
in natural sour gas treating plant. MDEA is an extremely selective amine that can be used for treating and absorption of hydrogen sulphide from both natural gas and refinery off-gasses. When require a higher carbon dioxide removal rate from gas stream, (as in the case of some LNG operators) or special requirement (corrosion and mercaptan management etc.), activated MDEA (aMDEA) is used. This is a combination of MDEA and activator (like piperizine) specifically formulated for required specification. This standard specification specifies purity, properties, test methods, inspection and packaging of MDEA and aMDEA.
2. REFERENCES
Throughout this standard specification the following standards are referred to. The editions of these standards that are in effect at the time of issue of this standard specification (2012) shall, to the extent specified herein, form part of this standard specification. The applicability of changes in standards that occur after the date of this standard specification shall be mutually agreed upon by the purchaser and the supplier.
ASTM D 93 (2007) "
Standard Test Methods for Flash Point by Pensky-Martens
Closed Cup Tester "
ASTM D 95 (2005) "
Standard Test Method for Water in Petroleum Products and
Bituminous Materials by Distillation"
ASTM D 445 (2006) "
Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (the Calculation of Dynamic Viscosity) "
ASTM D 891 (2004) "
Standard Test Methods for Specific Gravity, Apparent, of Liquid
Industrial Chemicals "
ASTM D 1015 (2005) "
Standard Test Method for Freezing Points of High – Purity
Hydrocarbons "
ASTM D 1078 (2005) "
Standard Test Method for Distillation Range of Volatile
Organic Liquids "
ASTM D 1177 (2007) "
Standard Test Method for Freezing Point of Aqueous Engine
Coolants
"
ASTM D 1209 (2005) "
Standard Test Method for Color of Clear Liquids (Platinum-
Cobalt Scale)
"
ASTM D 1218 (2002) " Standard Test Method for Refractive Index and Refractive
Dispersion of Hydrocarbon Liquids
"
1

N.I.G.C. March 2012 IGS-M-CH-050(0)
ASTM D 1364 (2002) " Standard Test Method for Water in Volatile Solvents (Karl
Fischer Reagent Titration Method)
"
ASTM D 2073 (1998) " Standard Test Methods for Total, Primary, Secondary, and
Tertiary Amine Values of Fatty Amines, Amidoamines, and Diamines by Referee
Potentiometric Method "
ASTM D 2074 (2007) "
Standard Test Methods for Total, Primary, Secondary, and
Tertiary Amine Values of Fatty Amines by Alternative Indicator Method
"
ASTM D 2080 (1998) "
Standard Test Method for Average Molecular Weight of Fatty
Quaternary Ammonium Chlorides
"
ASTM D 2766 (2005) "
Standard Test Method for Specific Heat of Liquids and Solids
"
ASTM D2879
()
" Standard Test Method for Vapor Pressure-Temperature
Relationship and Initial Decomposition Temperature of Liquids by Isoteniscope
"
BS 6829 Section 1.6 (1995) " Analysis of Surface Active Agents (Raw Materials) –
Part 1: General Methods – Section 1.6: Method for Determination of Solubility in
Water
"
DIN 51755 (1974) " Testing of Mineral Oils and Other Combustible Liquids;
Determination of Flash Point by the Closed Tester According to Abel-Pensky
"
DIN 51794 (2003) " Determination the Ignition Temperature of Petroleum Products "
3. DEFINITIONS
Methyldiethanolamine (MDEA)
Methyldiethanolamine is an organic chemical compound with molecular formula:
CH2CH2OH
H3C-N
CH2CH2OH
Activated methyldiethanolamine (aMDEA)
Activated methyldiethanolamine is an organic chemical compound combination of
MDEA and activator (like piperizine).
4. REQUIREMENTS
4.1 Purity
The composition of MDEA shall be in accordance with Table 1 when tested in accordance with specified test methods.
2

N.I.G.C. March 2012 IGS-M-CH-050(0)
The composition of aMDEA including values of MDEA, activator and water are specified by manufacturer and for each gas sweetening plant are unique. Because of various feed gas composition and CO2/H2S ratio shall be simulated and determined, so the maximum amount of impurities (Iron, Chloride and Sulfate) shall be in accordance with Table 1 when tested in accordance with specified test methods.
Annex C shows typical questionnaire for aMDEA evaluation.
Table 1 – Purity of MDEA
Item Content Value, wt% Test Method
1 MDEA, min 99
2
3
4
5
6
7
* MMEA, max
All secondary amines including
MMEA, max
Water, max
Iron
Chloride
Sulfate
0.2
0.5
0.5 nil nil nil
Gas Chromatography or
Ion Chromatography
Gas Chromatography or
Ion Chromatography
ASTM D 2074 or
Ion Chromatography
ASTM D 1364 or
ASTM D95
Ion Chromatography
ASTM D 2080 or
Ion Chromatography
Ion Chromatography
* MMEA: Methylmonoethanolamine
4.2 Properties of MDEA and aMDEA
The physical properties of MDEA shall be in accordance with Table 2 when tested in accordance with specified test methods.
The physical properties of aMDEA depending on composition of MDEA, activator and water should be changed. Annex D shows typical purity and physical properties of low and high activator MDEA that has been used in gas refineries.
3

N.I.G.C. March 2012 IGS-M-CH-050(0)
Table 2 – Physical Properties of MDEA
Item Characteristic Unit Value Test Method
1
2
3
4
5
Color, max
Gravity at 20 ºC, min
Viscosity at 20 ºC, min
Boiling point, min
Freezing point, min
APHA gr/cm^3 cP
ºC
ºC
50
1.04
101
243
-21
ASTM D 1209
ASTM D 891
ASTM D 445
ASTM D 1078
ASTM D 1177 or
ASTM D 1015
6 Flash point, min ºC 137 ASTM D 93 or
DIN 51755
7
8
9
Ignition point, min
Vapor pressure at 20 ºC
Solubility in water at 20 ºC
ºC mmHg
%
265
<0.01
100
DIN 51794
ASTM D2879
BS 6829 sec. 1.6
5. INSPECTION
The purchaser reserves the right to perform any inspections set forth in this standard specification where such inspections are deemed necessary to assure that supplies and services conform to the prescribed requirements.
The purchaser’s inspector reserve the right to have access to the material subject to inspection for the purpose of witnessing selection of the samples , preparation of the test samples and performance of the test(s).
For such tests, the inspector reserves the right to indicate the sample(s) from which the quantities will be taken in accordance with the provisions of this standard specification.
The manufacturer shall provide all means necessary for carrying out all inspections and tests as required by this standard specification.
The manufacturer shall set up and maintain such quality assurance and inspection systems to ensure that the material comply in all respects with the requirements of this standard specification.
4

N.I.G.C. March 2012 IGS-M-CH-050(0)
The supplier shall furnish to the purchaser a certificate of quality stating that each batch has been sampled, tested, and qualified in accordance with this standard specification and has been found to meet the requirements specified.
Tests and qualification records shall be available for review by the purchaser.
Inspection or tests carried out by the purchaser's inspector, in no way relieves the supplier of his responsibilities and liabilities under the requirements of this standard specification.
6. MARKING
6.1 Marking of Containers
Each container shall be legibly marked with at least following information:
Composition
MESC No.
Handling Guidelines
Safety precautions
Storage Symbols
Date of Manufacture
Date of expiry
Batch No.
Net weight
Gross weight
Order No.
HMIS (Hazardous Material Identification System including health, fire, reactivity, personal protection, specified hazard, etc)
6.2 Precautionary Marking
All individual containers shall be marked with precautionary symbols and/or phrases.
7. PACKAGING
7.1
The methyldiethanolamine (MDEA) and aMDEA shall be suitably packed in approved containers in accordance with the requirement of the purchase order.
Note: Empty space on containers must be free of oxygen and filled by inert gas (nitrogen), otherwise storage life is maximum 6 months (see clause 10).
7.2
The containers shall be protected against all damages or defects which may occur during handling.
7.3 The preferred material for storage of MDEA and aMDEA is 304L or 316L stainless steel. Carbon steel tanks are also satisfactory, although discoloration and iron in the amine may occur. The amine can also be stored in high-density polyethylene (HDPE) or polypropylene (HDPP). Materials to avoid include:
Aluminum, Copper, Brass, Copper alloy .
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N.I.G.C. March 2012 IGS-M-CH-050(0)
8. STORAGE LIFE
The methyldiethanolamine (MDEA) shall meet all requirements of this standard specification at least 24 months from date of delivery.
9. DOCUMENTATION
The manufacturer/supplier shall provide sufficient information and shall supply the technical information as a minimum requirement as follows:
- ISO 9001 certification for quality control of offered MDEA and aMDEA for treatment of natural sour gas issued by an internationally recognized body.
- Approval test reports, original technical catalogues, manufacturing product data sheet and application procedure recommendation and guidelines.
- Material Safety Data Sheet (MSDS).
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N.I.G.C. March 2012 IGS-M-CH-050(0)
ANNEX A
Data Sheet for MDEA
Manufacturer's name and address
Product designation
Purity of MDEA
Item
3
4
1
2
5
6
7
Content, %wt
MDEA
MMEA
Secondary amine
Water
Iron
Chloride
Sulfate
Physical Properties of MDEA
Item Characteristic
Value Test Method Remark
Unit Value Test Method Remark
3
4
5
6
7
8
9
1
2
Color
Gravity at 20 ºC
Viscosity at 20 ºC
Boiling point
Melting point
Flash point
Ignition point
Vapor pressure at 20 ºC
Solubility in water at 20 ºC
Notes:
1. This data sheet shall be filled, signed, and stamped by manufacturer/supplier.
2. Any deviation from this standard specification shall clearly be specified by manufacturer/supplier.
DEVIATION(S)
AUTORIZED SIGNATURE: COMPANY'S STAMP:
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N.I.G.C. March 2012 IGS-M-CH-050(0)
Manufacturer's name and address
Product designation
Purity of aMDEA
Item Content (%wt)
1
2
3
4
5
MDEA
Activated agents
MMEA
Secondary amine
Water
6 Iron
7
8
Chloride
Sulfate
Physical Properties OF aMDEA
Item Characteristic
ANNEX B
Data Sheet for aMDEA
Value
Unit Value
Test Method
Test Method
Remark
Remark
1 Color
2 Gravity at 20 ºC
3 Viscosity at 20 ºC
4 Freezing point
5
Flash point
6
Vapor pressure at 20 ºC
7
Solubility in water at 20 ºC
Notes:
1. This data sheet shall be filled, signed, and stamped by manufacturer/supplier.
2. Any deviation from this standard specification shall clearly be specified by manufacturer/supplier.
DEVIATION(S)
AUTORIZED SIGNATURE: COMPANY'S STAMP:
8

N.I.G.C. March 2012 IGS-M-CH-050(0)

N.I.G.C. March 2012 IGS-M-CH-050(0)
ANNEX C
Questionnaire for aMDEA Evaluation
(Informative)
To: Fax: Date:
CUSTOMER INFORMATION:
From:
Company:
Location:
Phone:
E-mail:
Fax:
GENERAL PLANT LAY-OUT:
ACID GAS
TREATED GAS OR LPG
LEAN AMINE
COOLER
ABSORBER
FILTERS
RICH-LEAN CROSS
HEAT EXCHANGER
FLASHED GAS
SOUR GAS OR LPG
RICH AMINE
FILTER FLASH DRUM
9
COOLER
REGENERATOR
REBOILER

N.I.G.C. March 2012 IGS-M-CH-050(0)
ABSORBER DETAILS
Source of feed
Flow:
Pressure:
Temperature:
NAME / NUMBER:
SOUR GAS CONDITIONS:
Design Actual
Nm 3 /h gas
º bara
C
SOUR GAS FEED COMPOSITION:
CO
2
mol% H
2
S mol%
H
2
CH
4 mol% C
2
H
6
C
2
H n-C
4
4
mol% C
3
mol% i-C
H
4
8 mol% C
3
H
6 mol% n-C
5 mol% mol% mol% i-C
5
mol% n-C
6
H
C
2
1
N
2 mol% O
2
O mol% COS
SH mol% C
Other components:
2
SH mol% mol% CS
2 mol% mol% mol% C
3
SH mol%
TREATED GAS SPECIFICATION REQUIRED:
CO
2 ppmv
Other sulfur components:
2
S COS mg/nm 3 gas
LEAN AMINE:
Temperature:
Design rate:
º
C Feed m 3 /h liquid Actual rate:
ABSORBER:
Diameter: mm Height: m 3 /h liquid
Tray spacing : mm Nominal size: mm mm mm
Weir height: mm
Downcomer width
Side:
Central: mm mm
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N.I.G.C. March 2012 IGS-M-CH-050(0)
REGENERATOR:
Rich amine
-
- Feed tray number:
Temperature:
Type of trays:
º
C
Number of trays:
Tray spacing : mm
Number of passes:
Weir height: mm
Downcomer width
Side:
Central: mm mm
NAME / NUMBER:
bara
Overhead pressure:
Overhead temperature:
Reflux flow rate:
bara
º
C m 3 /h
Type of packing:
Packing material:
Nominal size:
Packing height: mm mm
Weir height
Active or Bubbling
Area
Flow path
(here single pass
Downcomer width
REBOILER:
Number of reboilers:
Total design duty:
NAME / NUMBER:
11
Heat source: kcal/h Total actual duty: kcal/h

N.I.G.C. March 2012 IGS-M-CH-050(0)
RICH-LEAN CROSS HEAT EXCHANGER: NAME / NUMBER:
Total design duty:
Rich amine:
Temperature in:
Temperature out:
LEAN AMINE COOLER:
Total design duty:
ACID GAS COOLER:
Total design duty:
Gas temperature in:
FLASH DRUM:
º
º
C Temperature
C Temperature
NAME / NUMBER:
NAME / NUMBER: kcal/h Exchanger
º
C Gas temperature out:
NAME / NUMBER:
Operating pressure: bara
RICH AMINE MECHANICAL FILTER:
Total volume:
NAME / NUMBER:
Type: Nominal size of cartridges:
LEAN AMINE MECHANICAL AND CARBON FILTERS:
MECHANICAL FILTER BEFORE CARBON BED:
Type : Nominal size of cartridges:
CARBON BED:
Diameter: mm
Supplier and type of carbon:
MECHANICAL FILTER AFTER CARBON BED:
Type :
% of main circulation flow treated :
Nominal size of cartridges:
12 m
º m m
C m
3
2
2
3 m 2
º
C
º
C

N.I.G.C. March 2012 IGS-M-CH-050(0)
GENERAL BACKGROUND:
Current solvent used: Hot Pot
Total solution inventory:
Other amines: m 3
MDEA
Concentration:
DEA
REASON(S) FOR CONSIDERING AN ALTERNATE SOLVENT:
DIPA DGA wt%
Energy savings
Reduced CO
2
pick-up
Current operating problems:
COMMENTS / REQUESTS:
Increased capacity Reduced corrosion
Reduced Mercaptan in sale gas
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N.I.G.C. March 2012 IGS-M-CH-050(0)

N.I.G.C. March 2012 IGS-M-CH-050(0)
ANNEX D
Typical Purity and Physical Properties of aMDEA
(Informative)
D.1 Low Activator MDEA Purity
Item Property Specification Test method
1
MDEA >80 wt% GC
GC
GC
2
Activation agents
3
1
Secondary Amines
D.2 High Activator MDEA Purity
Item Property
MDEA
10 - 20 wt%
≤ 0.04 wt%
Specification
<50 wt%
2
3
Activation agents
Secondary Amines
≥ 50 wt%
≤ 0.04 wt%
D.3 Physical Properties for Low and High Activator MDEA
Item Characteristic Unit Value
3
4
1
2
Color
Gravity at 20 ºC
Viscosity at 20 ºC
Freezing point
APHA gr/cm 3 cP
ºC
≤ 100
>1.03
>100
<-35
5
6
7
Flash point
Vapor pressure at 20 ºC
Solubility in water at 20 ºC
ºC mmHg
%
>100
<1
100
Test method
GC
GC
GC
Test method
ASTM D 1209
ASTM D 891
ASTM D 445
ASTM D 1177 or
ASTM D 1015
ASTM D 93 or
DIN 51755
ASTM D2879
BS 6829 sec. 1.6
14