How to Calculate Maximum Pressure from Combustible Gas in a Vessel?

In summary, the conversation discusses calculating the maximum pressure inside a vessel when a known amount of combustible gas is ignited. The speaker is seeking guidance on how to use concepts such as heat of formation, heat of combustion, heat of explosion, enthalpy, and the ideal gas law to solve this problem. They also mention the need to consider the number of moles of gas, energy change, and temperature increase. The formula to convert energy change to temperature is mentioned, as well as the formula to calculate pressure using number of moles, gas constant, temperature, and volume.
  • #1
dimBulb
2
0
Hi,
I have no chemistry background and my head is swimming with heat of formation heat of combustion heat of explosion enthalpy ideal gas law and so on

What I'm trying to find out is how would I go about calculating the maximum pressure produced inside a vessel when a known amount of combustible gas was ignited?

i.e a hydrogen/air mixture inside a sealed 100ml container with a starting temperature of 25 deg C

Any examples or at least a point in the right direction is greatly appreciated.

Thank You.
 
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  • #2
For the steady state end point (ie. ignoring any shockwaves etc)
You would need the number of moles of gas at the start and the end - so if you were burning a solid/liquid fuel and ending up with a gas you are goign to have more pressure at the end just because there is more gas.
Then from the energy change you have to work out what temperaure increase the resulting gas is going to have.
 
  • #3
Thank You for the response,
Lets see if I understand this at all.
Hydrogen reaction with oxygen 2H2 + O2 --> 2H20
heat of formations 2H2 = 0 02 = 0 --> 2H20 2(-241.8) so the energy change is 483.6kj/mol ?
What formula(s) to I use to convert that to temperature?
once i have the temperature am I correct that
P = (number of moles * gas constant {8.314}* temp(k))/volume (100ml) and that pressure is in torr?

Thank you again.
 

FAQ: How to Calculate Maximum Pressure from Combustible Gas in a Vessel?

1. What causes explosive pressure in a vessel?

Explosive pressure in a vessel is caused by the rapid release of energy from a chemical reaction, which creates a sudden increase in pressure inside the vessel.

2. What are the potential dangers of explosive pressure in a vessel?

The potential dangers of explosive pressure in a vessel include structural damage, shrapnel or debris flying at high speeds, and the release of dangerous chemicals or substances.

3. How can explosive pressure in a vessel be controlled?

Explosive pressure in a vessel can be controlled by using proper containment methods, such as reinforced materials and safety valves, and by carefully monitoring and regulating the conditions inside the vessel.

4. What safety measures should be taken when working with vessels under high pressure?

When working with vessels under high pressure, safety measures such as wearing protective gear, following proper handling procedures, and conducting regular maintenance and inspections should be taken to minimize the risk of accidents.

5. What is the role of scientists in studying explosive pressure in a vessel?

Scientists play a crucial role in studying explosive pressure in a vessel by conducting research, developing safety protocols and regulations, and designing and testing materials and equipment that can withstand high pressures and prevent explosions.

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