How to calculate the quantity of odorant needed to add to LPG!

[quangkhoa90]

Dear Experts,

I am a junior process engineer. I would like to calculate the quantity of odorant needed to add to LPG (C3+C4)
Could you help me out please?
I did search on google, but I could find it nowhere

Thank in advance for your answers

Lee

 

[ashtree]

It will depend on the regulatory requirements of your country and the type of odorant you are using. Likewise your company will most likely have rules regarding the concentration.
Ethyl mercaptan dose is probably going to be about 12-15mg/l.


Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[LittleInch]

Never heard of it being applied to LPG before but agree that it is in the range of 10 ppm. The supplier of this horrible material will be able took advise.

Mercaptan is a substance hazardous to health and you can't afford to leak even a small drop.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[quangkhoa90]

Thank you for your answers,
There is actually no requirement regarding to the concentration of Ethyl Mercaptan (the odorant). We just inject an amount of 25 ppm as the supplier recommends. But through the info collected, threshold of detection of this ordorant is 1 ppb, so I calculated the amount needed must be about 100 ppm
I am not sure about my calculation of course

Lee

 

[ashtree]

This concerns me because this is pretty basic process work.
In what respect are you unsure of your calculations?

What information do you have?

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[LittleInch]

1ppb is presumably quantity in air

1000ppb is 1 ppm

Assuming the mercpatan vaporizes at the same rate as the LPG the same concentration applies.

But LPG burners usually work on about 1:30 gas air mix so needs to be 30ppb to make it 1ppb in air.

within any system even that is a small fraction of the air in a room so add a factor of at least 10 - 300 ppb

Ad din that the 1ppb is the limit of smell so again add a factor of 10 to make it instantly "smellable" - 3000ppb = 3ppm

Mercaptan suppliers want to use more of their material than you normally need... (cynical hat on)
So "recommended" dosage is 25ppm - seems pretty high to me but might be based on the levels used in natural gas where burner air ratios are more like 1: 10 so only need a third of the same material to make the same smell.

"There is actually no requirement regarding to the concentration of Ethyl Mercaptan (the odorant). " - So why are you doing it????



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[chicopee]

The amount of odorant to be added to LPG should be based on its odor threshold limit of the odorant in air. How much is to be added to the LPG, I would advice to read NFPA 58 since there will be a lower flammability limit of LPG involved.

 

[bimr]

Texas is definitely a strange place.

1. No zoning. Look at the effects with Hurricane Harvey.

2. Aftermath of the West Texas ammonium nitrate explosion is that hazardous chemical lists are no loner public record in Texas so that people live in close proximity to hazardous facilities.

The 2013 fertilizer plant blast in Texas that killed 15 people (including first responders), 160-200 non-fatal injuries, and wiped out hundreds of homes.

"Williams cited an Attorney General's (Governor Abbott at that time) ruling from May 22, 2014, which denied public access to "Tier Two information [...] because it reveals the location, quantity and identity of hazardous chemicals [...] likely to assist in the construction of an explosive weapon.""

http://www.kvue.com/news/state/hazardous-chemical-lists-no-longer-public-record-in-texas/260123599

The CSB’s investigation found that several factors contributed to the severity of the explosion, including poor hazard awareness and fact that nearby homes and business were built in close proximity to the West Fertilizer Company over the years prior to the accident. The video explains that there was a stockpile of 40 to 60 tons of ammonium nitrate stored at the facility in plywood bins on the night of the explosion. And although FGAN is stable under normal conditions, it can violently detonate when exposed to contaminants in a fire.

http://www.csb.gov/csb-board-approv...rt-and-recommendations-with-a-unanimous-vote/