6-1. The flash point of the mixture occurs when the partial pressure of methanol is equal to the
vapor pressure of pure methanol at the flash point temperature.
From Appendix B, the flash point temperature for methanol is 11oC = 284.5 K
At the flash point temperature of 284.5 K
The partial pressure is given by
6-2. First compute the mole fraction on a combustible basis only, ignoring the non-combustible
air. We can obtain the flammable limits from Appendix B. So we have:
Then we use Equations 6-2 and 6-3 to compute the LFL and UFL of the mixture.