Vapor Recovery

Written by Jerry Ratzlaff. Posted in Tank

A vapor recovery system is a series of components that work together to keep fugitive emissions from escaping into the surrounding environment.  In a facility, a tank vapor recovery system takes gas that is entrained in the production fluids and compresses it for further processing.   Environmental restrictions or personnel safety will often times dictate the need for a TVR system.

A casing vapor recovery system is hooked up to a well head on the casing valve.  By decreasing the pressure in the annulus, the theory is that the back pressure on the formation decreases and produces more.

Tank Vapor Recovery

Tank Vapor Recovery (TVR) systems are installed on tanks to caputre gas that is displaced due to rising fluid in the tank.  A back pressure control valve is installed on the vapor space on the tank regulating the pressure in the tank.   As the pressure increases in the tank, the regulator opens to relieve pressure building up in the tank.  It either opens to the atmosphere or into a  TVR system that captures the gas for reuse or incineration. 

The capacity requirement of a TVR system depends on two things.  First, inbreathing & outbreathing due to filling and discharge of the tank.  This is usually dictated by the process or by code.  For example, API 2000 - Venting Atmospheric and Low-Pressure Tanks dictates the normal venting requirements for tanks.  Secondly, environmental conditions should be considered.

 

abbreviations

  • CVR - casing vapor recovery
  • TVR - tank vapor recovery
  • VR - vapor recovery