6 replies to this topic

[chemilocha]

Dear All,

 

 

Guys we are going to operate LPG offloading terminal. I need some reference/sample odorant dosing calculation.

 

Total LPG flow rate is 224 m3/hr (7 pump working , each pump- 32 m3/hr)

now, i would like to calculate the ethyl mercaptan dosing rate to the LPG flow line @ 15 PPM 

 

can anybody provide me sample calculations or any reference code or standards followed in the oil and gas industry.

 

Thanks.

[Bobby Strain]

It's simple arithmetic.

[breizh]

Hi ,

Should be easy if you define PPM volume or PPM mass !

 

 volume or (mass mercaptan) / volume or (mass LPG) = 15 e-06

 

mass = volume *density

 

hope this is helping you

Breizh

[N243]

Hi Chemilocha,

 

It is indeed simple arithmetic. I can demonstrate below :

 

Assumptions:

1. Operating flowrate of LPG is taken as 224 m³/hr

2. PPM is expressed in volumetric basis.

 

Calculation :

• 15 PPM of Ethyl Mercaptan is the same as 15 mg of Ethyl Mercaptan/ 1 Liter of LPG.
• Now, LPG flowrate of 224 m³/hr equates to 224000 liters/hr.
• Multiplying 224,000 Liters/Hour with 15 mg/ liter = 3,360,000 mg of Ethyl Mercaptan required per hour.
• Answer = 3.36 kg/hr of Ethyl Mercaptan required

I hope this clears up any confusion.

 

Kind Regards,

N243

[breizh]

N243,

Very confusing your calculation !  Either it's PPM volume or PPM mass .

 

note : 1 PPM volume = 1ml ethyl mercaptan per m3 LPG

 

if PPM volume , the answer is 3.36 liters /hour of Ethyl mercaptan for 224 m3/h of LPG

 

Breizh

Edited by breizh, 17 October 2019 - 05:27 AM.

[chemilocha]

Dear All,

 

thanks for your valuable response to the query.

 

Mr Bobby , yeah its simple arithmetic calculations but i want to verify my calculations with forum members.

 

Mr breizh , appreciate your answer. its matching with my calculations  too , 3.36 Litres/hour .  :thumbsup:

 

 

Now Suppose, if i want to calculate in terms of mass PPM, Considering LPG  density - 530 kg/m3

 

then  the required ethyl mercaptan at 15 PPM  will be 1.7808 kg/hr ??  

 

regards,

chemilocha

[breizh]

Hi ,

Yes 1.7808 kg/h . Considering a density of 860 kg/m3 for E.M the flow rate should be about 2.07 l/h .

Breizh