Hilliard Emission Controls, Inc.
3100 Edloe Street Suite 350, Houston TX 77027
888-621-3132    (fax 713-621-3112)
 PURGIT logo

Use a condenser to control emissions during degassing and cleaning.
For: floating & fixed roof tanks, rail cars, cargo tanks, etc.  
Not just a small carbon footprint, we actually recover the hydrocarbons.


PURGIT closed loop system

The PURGIT system has a vapor control device that can degas a tank without opening the tank. Our condenser system draws the vapors out of the tank and pushes them through a series of condensers. Vapors are condensed and the condensate is collected and transferred to storage. The non-condensable gases are returned to the storage tank. Nitrogen can be added to maintain the volume and keep air out.

The most interesting thing about the PURGIT system is that we have made a new benchmark for the amount of cargo that is in the vapor space of a tank. Have you ever heard the combustor contractor say 'the tanks aren't that bad' and finish the job in a short time frame? We know how to get virtually all the condnesable vapors out of a tank. Since we recover, we have put a new performance mandate that requires the combustor to be on line with enough capacity to actually process the vapors. There is nothing unusual about recovering thousands of pounds of gasoline from a tank. That would take many hours of combustor time. When the the combustor burns a pound of VOC they make a pound of combustion by-procucts such as unburned VOC, NOx, CO, CO2 and greenhouse gases that is released directly into the air you breathe.

Our process is different. Our condensers do not even have exhaust stacks. We recover the condensate and it can be recycled. In just a few months, we condensed and recovered over 91 tons of condensate. That is not a small amount since otherwise it would be in the air over Houston TX, the Houston Ship Channel and places we work. We know how to recover the VOC without releasing it to the air.

With a refrigerated ‘closed-loop’ system the following benefits are realized:

  1. Fast. Refrigeration is ideal for concentrated vapors. We are at full flow from minute #1 to completion.
  2. Safe. There is no burning, no open flame as in a combustor, thereby increasing safety in tank farms. There is no unprotected source of ignition. The liquid nitrogen we use is not flammable and it is not a pollutant.
  3. Zero CO2, NOx, almost zero emissions. Since there is no combustion in the PURGIT process, it effectively eliminates CO2 and NOx from combustion. The condensers do not have exhaust stacks. Non condensables are returned to the cargo tank.
  4. Chlorinated solvents can be controlled without scrubbing. Unlike combustion which produces negative byproducts, condensation recovers the cargo. Carbon is ineffective and just transfers the problem. No system is more effective with chlorinated solvents.
  5. Hydrocarbon VOC’s are just as easily controlled. Liquid nitrogen refrigerant is capable of condensing many cargoes. We put the condnesate in totes and it can be recovered.
  6. Efficient. The ‘closed-loop’ system is very efficient when dealing with high concentrations. Unlike combustors that struggle with heat load from rich vapors, condensers work well with concentrated inlet vapors.
  7. Mobile! The PURGIT ‘Closed-Loop” vapor control system is mobile. It can go where the tank is, or can be a permanent, stationary asset to a facility.
  8. May not need a permit. Use the PURGIT 'closed loop' vapor control system to reduce the tank vapors to the point where you can legally begin open venting and you should not need a permit for air emissions from tank cleaning.
  9. Cost. The PURGIT system will cost  the same or less than a similar size combustor with a scrubber or activated carbon system. Operating expenses should be less than carbon. Additional cost savings may also be realized from recovered cargo. 
  10. No control device has a smaller carbon footprint than PURGIT. We have recovered thousands of gallons of chlorinated solvents and hydrocarbon VOC’s.
750 gallons of recovered hydrocarbons EDC condensate chloroform from tank barge
750 gallons of recovered hydrocarbons
from a storage tank
 450 gallons of EDC from a tank barge
 135 gallons of chlorororm from a tank barge

The PURGIT ‘Closed-Loop system is an environmentally friendly solution. It is superior to all combustion systems for floating or fixed roof tank degassing. Call PURGIT in Houston, Texas if this type of vapor control equipment could be useful to you.

Patented. PURGIT is a registered trademark of Hilliard Emission Controls, Inc.              Return to PURGIT emission control home page