[RomanKatz]

Hello friends,

I have a double jacket heating vessel (2000 kg batch) producing a polymeric product. it is stated that 0.05%wt of the batch is hexane gas that is emitted to the atmosphere. How can I calculate how much PPM is emitted?

Thanks

[Hunter2]

0,05% is 0.05/100. This correspond to x/1000000.

Solve for x.

[RomanKatz]

What about temp, or molecular weight? Aren’t they important factors?

[Aldebaran]

 Can you give some context? For example are you thinking about the likely concentration of the emissions / plume?

[Borek]

Question as posted is way too ambiguous, it is really not clear what you ask.

ppm of what in what?

[prankster1590]

Hello friends,

I have a double jacket heating vessel (2000 kg batch) producing a polymeric product. it is stated that 0.05%wt of the batch is hexane gas that is emitted to the atmosphere. How can I calculate how much PPM is emitted?

Thanks

2000 kg*0,0005 = 1 kg = 11,6 moles of Hexane released to the atmosphere. The density air is about 1,2 g/l which would not change significally by the addition of 1 kg hexane.

So if your lab is like 5x5x2,2 = 55 m³ = 55000 liters is about 55000*1,2=66000 grams of air = 66 kg + 1 kg hexane = 67 kg

ppm =mg/kg so 1000000 mg hexane/67 kg total air mass = about 15000 ppm of hexane in the atmosphere.

If your lab is airtight without a fumehood

PS/btw: dont know if this calculation is correct

[RomanKatz]

Hello again,
To make things clear, the reaction that occurs in the vessel is mixing base stock oil with bulk of polymer that dissolves in the oil via heating (about 100deg C) and mixing. It is stated that 0.05% weight of the batch transforms into hexane gas (I assume a side reaction). So I would like to know how much PPM hexane is produced since its gas and then to find out what safety and detection measures I need to make so this vessel is safe to operate outdoors by a personal, minimizing potential health issues.
Regarding chemical reaction and emissions of hexane i cant say exactly how it is produced(low level constant emission that adds up to 0.05% or a concentrated sudden emission burst or else) since we don't have the system  yet.

I have talked to a chemical engineer and he said that I need to use arrhenius equation.

Hope this helps

[Borek]

So I would like to know how much PPM hexane is produced

More or less you are asking something like: I have 2 kg of water. How many percent it is?

Also: I don't see how Arrhenius equation (one that says how the reaction speed changed with the temperature) can help here.

Best you can do is a guesstimate like the one prankster1590 posted, with some assumptions about volume of gas involved.

[Aldebaran]

Sounds like you are running an industrial process at 2000kg batch sizes and you have operators (employees) involved. Just get a certified emissions testing company to measure your emissions properly.

[RomanKatz]

I hope to run it someday, this is all on paper only. So I am wondering how serious the hexane emissions could be.