Hydrogen Sulfide (H2S) Safety 2

[ControlMonkey]

I've been given the task of H2S monitoring for a power plant. I'm trying to find out if there are any regulations, specifications, or just basic guidelines for open area monitoring for Hydrogen Sulfide(H2S). Any help would be amazing.

 

[JLSeagull]

I too would love to see some standardized detector placement criteria. A lot of individual judgement is required. Strong opinions likely exist among the critics of your plan.

I doubt that the power plant is using sour gas for fuel. Obtain process stream data that identifies the streams that likely contain hydrogen sulfide in excess of about 20 ppm. Identify other potential sources such as sumps, drains, dikes etc. where heavy gas could collect due to other orgainic processes.

Most people use point H2S gas detectors placed within about 0.5 meter above the grade within less than 15 meters of the likely sources. Fifteen foot might be better. Apply more in the predominent downwind direction than upwind. Many suppliers are proven for this. Frequent testing is required, quarterly minimum and monthly checking common. These detectors can drift. Different sensors are better for wet or dry areas. New technologies include open path detection using tunable laser diode analytical techniques. Few suppliers are ready for the industry.

If a serious hazard exists require the employees to wear personal detectors and to carry evac masks.

Codes and standards include the following:
API RP 55 Oil and Gas Operations,
ISA 92.0.01, 92.0.02, 92.2.21,
NACE MRO103
EPA Method 11 for H2S in fuel and Performance Spec 7 for H2S in the CEMS monitoring
OSHA limits
29 CFR 1910.1000

http://www.osha.gov/dts/sltc/methods/inorganic/id141/id141.html

Texas Railroad Commission Rule 3.36

 

[ControlMonkey]

You are correct, we are not using sour gas to run the generators, however this area is surrounded by natural gas processing plants which have extrememly high sulfur content.

Were it not for the proximity of these other plants the H2S sensors would not be required.

Thank you for the stnadards.

 

[JLSeagull]

I regard open path gas detection as ideal for "Across the Fence" perimeter applications.

Although not industry proven in my opinion, Senscient offers open path detection that you may find of interest. Their laser diode spectrometers can be setup to detect hydrogen sulfide and combustible gas releases. This product also shows up with the Sensidyne name.

Spectrex offers xenon flash UV open path detection for H2S. My pdf files include Gastech Australia as a company name and SafEye as the product name. This also shows up with the MSA and Sierra Monito SMC logos.

Perhaps one of these vendors is among your acceptable manufacturers.

 

[Unotec]

I'd support the personal monitors as JS mentioned. H2S can be sneaky. But don't the gas plants have their own detection systems? Just mnake sure you're attached to their ESD response system and alerted of a release.

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