SIST EN ISO 6326-3:2000

Natural gas - Determination of sulfur compounds - Part 3: Determination of hydrogen sulfide, mercaptan sulfur and carbonyl sulfide sulfur by potentiometry (ISO 6326-3:1989)

Specifies a potentiometric method for components in natural gas in the concentration range equal to or above 1 mg/m3. The gas must be free of dust, mist, oxygen, hydrogen cyanide and carbon disulfide. The method is not recommended for gases containing more than approximately 1,5 % (V/V) carbon dioxide.

Erdgas - Bestimmung von Schwefelverbindungen - Teil 3: Bestimmung von Schwefelwasserstoff, Mercaptanschwefel und Kohlenstoffoxidsulfidschwefel durch Potentiometrie (ISO 6326-3:1989)

Dieser Teil von ISO 6326 legt ein potentiometrisches Verfahren zur Bestimmung von Schwefelwasserstoff, Mercaptanschwefel und Kohlenstoffoxidsulfidschwefel in Erdgas im Konzentrationsbereich größer/gleich 1 mg/m3. Das Gas muß frei von Staub, Nebel, Sauerstoff, Cyanwasserstoff und Schwefelkohlenstoff sein. Das Verhältnis von Schwefelwasserstoff zu Mercaptanschwefel und auch das Verhältnis von Mercaptanschwefel zu Schwefelwasserstoff soll 50 : 1  nicht überschreiten. Das Verfahren wird nicht für Gase empfohlen, die mehr als etwa 1,5 % (V/V) Kohlenstoffdioxid enthalten.

Gaz naturel - Détermination des composés soufrés - Partie 3: Détermination du sulfure d'hydrogene, des thiols et du sulfure de carbonyle par potentiométrie (ISO 6326-3:1989)

La présente partie de l'ISO 6326 prescrit une méthode potentiométrique pour la détermination du sulfure d'hydrogène, des thiols et du sulfure de carbonyle dans le gaz naturel, dans une plage de concentrations supérieures ou égales à 1 mg/m3. Le gaz doit être exempt de poussière, de fumées, d'oxygène, de cyanure d'hydrogène et de sulfure de carbone. Le rapport sulfure d'hydrogène/thiols ainsi que le rapport thiols/sulfure d'hydrogène ne doivent pas dépasser 50 : 1. La méthode n'est pas recommandée pour les gaz contenant plus d'environ 1,5 % (V/V) de dioxyde de carbone.
NOTE -- Dans toutes les parties de l'ISO 6326, 1 m3 de gaz est exprimé pour les conditions normales (0 °C; 101,325 kPa).

Zemeljski plin - Določevanje žveplovih spojin - 3. del: Določevanje vodikovega sulfida, merkaptanskega žvepla in ogljikosulfidnega žvepla s potenciometrijo (ISO 6326-3:1989)

General Information

• Status: Withdrawn
• Publication Date: 30-Nov-2000
• Withdrawal Date: 22-Apr-2020
• ICS: 75.060 - Natural gas
• Technical Committee: NAD - Petroleum products, lubricants and related products
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 17-Apr-2020
• Due Date: 10-May-2020
• Completion Date: 23-Apr-2020
• Ref Project: EN ISO 6326-3:1997 - Natural gas - Determination of sulfur compounds - Part 3: Determination of hydrogen sulfide, mercaptan sulfur and carbonyl sulfide sulfur by potentiometry (ISO 6326-3:1989)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 6326-3:2000
01-december-2000
=HPHOMVNLSOLQ'RORþHYDQMHåYHSORYLKVSRMLQGHO'RORþHYDQMHYRGLNRYHJD
VXOILGDPHUNDSWDQVNHJDåYHSODLQRJOMLNRVXOILGQHJDåYHSODVSRWHQFLRPHWULMR,62

Natural gas - Determination of sulfur compounds - Part 3: Determination of hydrogen
sulfide, mercaptan sulfur and carbonyl sulfide sulfur by potentiometry (ISO 6326-3:1989)
Erdgas - Bestimmung von Schwefelverbindungen - Teil 3: Bestimmung von
Schwefelwasserstoff, Mercaptanschwefel und Kohlenstoffoxidsulfidschwefel durch
Potentiometrie (ISO 6326-3:1989)
Gaz naturel - Détermination des composés soufrés - Partie 3: Détermination du sulfure
d'hydrogene, des thiols et du sulfure de carbonyle par potentiométrie (ISO 6326-3:1989)
Ta slovenski standard je istoveten z: EN ISO 6326-3:1997
ICS:
75.060 Zemeljski plin Natural gas
SIST EN ISO 6326-3:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 6326-3:2000

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SIST EN ISO 6326-3:2000

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SIST EN ISO 6326-3:2000

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SIST EN ISO 6326-3:2000
INTERNATIONAL
ISO
STANDARD 6326-3
First edition
1989-07-01
Natura1 gas - Determination of Sulfur
compounds -
Part 3 :
Determination of hydrogen sulfide, mercaptan Sulfur
and carbonyl sulfide Sulfur by potentiometry
Gaz naturel - Determination des composh soufrks -
Partie 3 : D6 termina tion du sulfure d’h ydrogkne, des thiols et du sulfure de
par po ten tiome trie
carbon yfe
Reference number
ISO 6326-3 : 1989 (El

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SIST EN ISO 6326-3:2000
ISO 6326-3 : 1989 (El
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of
national Standards bodies (ISO member bodies). The work of preparing International
Standards is normally carried out through ISO technical committees. Esch member
body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, govern-
mental and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the ISO Council. They are approved in accordance with ISO procedures requiring at
least 75 % approval by the member bodies voting.
International Standard ISO 6326-3 was prepared by Technical Committee ISO/TC 158,
Analysis of gases.
ISO 6326 consists of the following Parts, under the general title Natura/ gas -
Determination of Sulfur compounds :
- Part 7: General introduction
- Part 2: Gas chromatographic method using detector for the
an elec trochemical
determination of odoriferous Sulfur compounds
- Part 3: Determination of hydrogen sulfide, mercap tan Sulfur and carbon yl
suffide Sulfur b y po ten tiometry
-
Part 4: Determination of individual Sulfur compounds chroma tograph y
bY PS
with a flame pho tome tric de tec tor
- Part 5: Lingener combustion method
0 ISO 1989
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronie or mechanical, including photocopying and microfilm, without Permission in
writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland
ii

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SIST EN ISO 6326-3:2000
ISO 6326-3 : 1989 (El
lntroduction
The standardization of several methods for the determination of Sulfur compounds in
natura1 gas is necessary in view of the diversity of these compounds [hydrogen sulfide,
carbonyl sulfide, thiols (mercaptans), tetrahydrothiophene (THT), etc.] and the pur-
poses of the determinations (required accuracy, measurement at the drilling head or in
the transmission pipes, etc. 1.
In Order to enable the user to choose the method most appropriate to his needs and to
perform the measurements under the best conditions, ISO 6326 has been prepared in
several Parts.
rapid com
ISO 6326-1 gives a parison of standardized methods and therefore provides
information for the choice of the method.
The other Parts of ISO 6326, including this Part, describe in detail the various stan-
dardized methods.
The determination of total Sulfur is specified in ISO 4260 : 1987, Petroleum products
Determination of Sulfur content - Wickbold combustion
and hydrocarbons -
method.

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SIST EN ISO 6326-3:2000
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SIST EN ISO 6326-3:2000
ISO 6326-3 : 1989 (E)
INTERNATIONAL STANDARD
Determination of Sulfur compounds -
Natura1 gas -
Part 3 :
Determination of hydrogen sulfide, mercaptan Sulfur and
carbonyl sulfide Sulfur by potentiometry
3 Principle
1 Scope
This part of ISO 6326 specifies a potentiometric method for the
Hydrogen sulfide and mercaptans are absorbed in a 35 %
determination of hydrogen sulfide, mercaptan Sulfur, and car-
(mlm) aqueous potassium hydroxide Solution and carbonyl
bonyl sulfide Sulfur in natura1 gas in the concentration range
sulfide in a 5 % (mlm) ethanoholic monoethanolamine solu-
equal to or above 1 mg/m3. The gas must be free of dust, mist,
tion. The solutions are titrated potentiometrically using silver
Oxygen, hydrogen cyanide and carbon disulfide. The hydrogen
nitrate solutions with a silverkilver sulfide electrode System to
Sulfur ratio and also the mercaptan
suIfide/mercaptan
indicate the end Point.
sulfur/hydrogen sulfide ratio should not exceed 50 : 1.
The method is not recommended for gases containing more
than approximately 1,5 % ( Vl V carbon dioxide.
4 Reagents and materials
NOTE - In all Parts of ISO 6326, 1 m3 of gas is expressed at normal
During the analysis, use only reagents of recognized analytical
conditions (0 “C; 101,325 kPaL
grade and only distilled water or water of equivalent purity.
2 Normative references
4.1 Potassium hydroxide, Solution.
The following Standards contain provisions which, through
Dissolve 35 g of potassium hydroxide (KOH) in 65 g of water.
reference in this text, constitute provisions of this part of
ISO 6326. At the time of publication, the editions indicated
NOTE - In Order to prevent interference by heavy metal ions, 0,5 g of
were valid. All Standards are subject to revision, and Parties to
a mixture of polyaminoacetic acids is added for each 50 ml of absorp-
agreements based on this part of ISO 6326 are encouraged to
tion solution to inactivate the heavy metal ions,
investigate the possibility of applying the most recent editions
of the Standards listed below. Members of IEC and ISO main-
The mixture consists of equal Parts of
tain registers of currently valid International Standards.
the pentasodium salt of diethylenetriam ne pentaacetic acid
(NasDTPA);
ISO 385-1 : 1984, Laboratory glassware - Burettes - Part 7 :
General reguiremen ts.
the trisodium salt of N-hydroxyethylenediamine triacetic acid
(NasHEDTA);
ISO 648 : 1977, Laboratory glassware - One-mark pipettes.
the sodium salt of N,N-di(2-hydroxyethyl-glycin) (NaDHEG);
One-mark
ISO 1042 : 1983, Laborstory glassware - the tetrasodium salt of ethylenediamine
tetraacetic acid
volume tric flasks. (Na,EDTA).
1

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SIST EN ISO 6326-3:2000
ISO 6326-3 : 1989 (EI
5.6 One-mark volumetric flask, of capacity 1 000 ml,
4.2 Monoethanolamine, Solution.
complying with ISO 1042.
Dissolve 5 g of monoethanolamine (C2H70N) in 95 g of
ethanol.
5.7 High-resistance Voltmeter, range 1 000 mV, accuracy
better than + 5 mV. (An automatic titrimeter may be used,
providing that it meets the above specification.)
4.3 Nitrogen, purity better than 99,95 %, Oxygen-free,
under pressure.
5.8 Silver/silver sulfide measuring electrode
4.4 Siber nitrate, Standard volumetric Solution, c(AgN03)
NOTE - Ion-selective silver/silver sulfide crystal membrane electrodes
= 0,Ol mol/l.
are commercially available and allow faster and more precise titration,
especially at low Sulfur concentrations. If such an electrode is not
For the preparation of the silver nitrate Solution use boiled
available, a conventional silver/silver sulfide electrode may be prepared
distilled water, cooled to 20 OC while bubbling with nitrogen
according to the following procedure.
(4.31, to remove all traces of Oxygen.
Prepare a Solution of sodium sulfide and sodium hydroxide by dissolv-
ing 1,2 g of sodium sulfide nonahydrate (Na$,9H20) and 40 g of
Dissolve about 1,7 g of silver nitrate in 200 ml of water in the
sodium hydroxide in 1 litre of water.
1 000 ml one-mark volumetric flask (5.6) and make up to the
Clean the silver metal of the electrode with fine abrasive Paper and im-
mark with water. Standardize the Solution with hydrochloric
merse it in 100 ml of the sodium sulfide/sodium hydroxide solution, stir
acid Ic(HCI) = 0,Ol mol/ll.
the Solution and add 10 ml of the silver nitrate Solution (4.4) over a
period of 10 min to 15 min. Remove the electrode from the solution,
wash it with water and wipe it lightly with a clean cloth. The coating
Ammonium hydroxide Solution (Q~ oc = 090 g/ml).
4.5
should last for several weeks.
Before use, soak the electrode for at least 5 min in 100 ml of the elec-
4.6 Electrolyte Solution.
trolytic Solution (4.6) to which 0,5 ml of silver nitrate Solution (4.4) has
been added. Store the electrode in this Solution.
hydroxide
Mix 1 000 ml of methanol and 25 ml of ammonium
Solution (4.5).
5.9 Silver/silver chloride reference electrode.
4.7 Cotton-wool, for the removal of dust.
5.10 Electric stirrer.
6 Sampling
5 Apparatus
On-line sampling is recommended. In the case where indirect
Ordinary laboratory apparatus and
sampling is indispensable, use sampling cylinders in accord-
ante with clause 3 of ISO 6326-1 : 1989.
5.1 Test apparatus, (sec figur
...