METHODS FOR ESTIMATING THE CONCENTRATIONS OF GAS-PHASE SPECIES WITHIN A PROCESS VESSEL FROM DOWNSTREAM SAMPLES

摘要

A method for estimating a gas concentration of a compound of interest within a process vessel for permitting safe entry into the process vessel comprises: exposing the process vessel to a condensing fluid to dissolve gases therein; collecting liquid comprising the condensing fluid from a location downstream of the process vessel; sealing the liquid in a sample container to yield a condensate sample; measuring and/or calculating properties of a liquid portion and a gas portion of the condensate sample; calculating a process vessel condensate density; determining a thermodynamic equilibrium correction factor; calculating the gas concentration of the compound of interest in the process vessel based on the properties of the condensate sample, a thermodynamic equilibrium correction factor, the process vessel condensate density, and optionally, a safety factor; and determining when the calculated gas concentration of the compound of interest in the process vessel permits safe entry into the process vessel.