Screening method for assessing the H
The present invention relates to method for assessing the H 2 S release capacity of a liquid sample containing one or more sulfur compounds which are able to be degraded into gaseous H 2 S with temperature. The method comprising: a) Placing a volume of the liquid sample in a purge vessel so as to obtain a liquid phase and a gaseous phase in a flask; b) Purging the gaseous phase with an inert gas stream for a determined period of time; e) Passing the purged gaseous phase through a H 2 S trap; d) Recovering H 2 S from the H 2 S trap; and e) Dosing the recovered H 2 S. The invention is also used in a method for selecting a liquid sample, in particular among a group of different liquid samples.
1. A method for measuring the H 2 S release capacity of a liquid sample containing one or more sulfur compounds which are able to be degraded into gaseous H 2 S with temperature, said method comprising the following steps:
a) Placing a volume of the liquid sample in a purge vessel so as to obtain a liquid phase and a gaseous phase in a flask;
b) Purging the gaseous phase with an inert gas stream for a determined period of time;
c) Passing the purged gaseous phase through a H 2 S trap;
d) Recovering H 2 S from the H 2 S trap; and
e) Measuring the recovered M 2 S,
wherein the purge vessel is kept at a temperature from 45° C. to 60° C., and
wherein the liquid sample is a corrosion inhibitor, an oil wetting agent, a solid dispersing agent, a scale inhibitor, an anti-foulant, an oxygen scavenger, a foaming agent, or a mixture thereof.
2. The method according to claim 1 , wherein the sulfur compound is a thiol, a thio-ether or a thioacid.
3. The method according to claim 1 , wherein the liquid sample has a boiling temperature of at least 80° C.
4. The method according to claim 1 , wherein the flow rate of the inert gas stream during steps b) or c) is from 20 mL/min to 90 mL/min.
5. The method according to claim 1 , wherein the inert gas is chosen from helium, nitrogen or hydrogen.
6. The method according to claim 1 , wherein the period of time of the purging step b) is from 2 min to 12 min.
7. The method according to claim 1 , wherein the trapping step c) is performed by cryofocusing, adsorption, absorption, or gas-solid reaction with a captation mass.
8. The method according to claim 1 , wherein the measuring step e) is performed by gas chromatography coupled with mass spectrometry, thermogravimetric analysis coupled with mass spectrometry, or elemental analysis for sulfur.
9. A method for selecting a liquid sample among a group of different liquid samples, said method comprising the following steps:
Measuring the H 2 S release capacity of each liquid sample according to the method as defined in claim 1 ; and
Selecting the sample which has the lowest H 2 S release capacity.
10. A method for selecting a liquid sample, said method comprising the following steps:
Measuring the H 2 S release capacity of each liquid sample according to the method as defined in claim 1 ; and
Comparing the H 2 S release capacity with a threshold value.