(97e) Steam Control in Elevated Steam Assisted Flares

Steam assisted flares are commonly used in the petrochemical industry.   Over-steaming of these flares can be a cause of incomplete combustion. But, the question of just how much steam is too much has been difficult to answer.   In 2010,  Flint Hills Resources Port Arthur, LLC (FHR) Port Arthur Chemicals (PAC) facility  conducted a Passive Fourier Transform Infra-Red (PFTIR) study on two flares to explore the relationship between steam flow and combustion efficiency.    The results of the test were used to develop parameters that could be used by FHR and others in the industry to minimize the potential of over-steaming the flares.   This paper will discuss: 

1. What is PFTIR and how was the test conducted? 
2. How much steam was required at different vent gas rates, and how did that compare to the design guidelines from API-521? 
3. What parameters are the most effective predictors for combustion efficiency?  
4. What control strategies and equipment work well for good steam to vent gas (S/VG) control?