The first vapor condenser C-1 with
 a crude oil tank in the background.
Started condenser service in 1999

Unit C-2 built 12/06
Placed in service 3/07 Recovered over 80 tons VOC
liquid in just 16 months!

Unit C-2 recovered this ethylene dichloride
 from one tank in about 8 hours in Dec 07
It is suitable for recycling.

Gasoline type VOC condensate
recovered by PURGIT condenser C-2
April 2008 final recovery over 2,000 gallons

100,000 barrel cap. storage tank - isoprene
Final recovery 5,500 gallons. Recovered and transfered
to adjoining pipeline segment. Feb 2008 by PURGIT C-2

Butane pipeline site near Chicago
Recovered and pumped to tanker
over 1,100 gallons of butane March 2008
PURGIT unit C-2

Here is the PURGIT mobile vapor condenser on site degassing a gasoline tank. In the photo you can see the liquid nitrogen tanker, the condenser trailer, the PURGIT truck and an air compressor. There is a detonation arrester on the inlet to the condenser and a turbine meter to accurately measure the volume processed. The hoses go to the storage tank. One hose is the suction hose and the other hose is the return hose.

This photo shows the hoses going to the tank. One hose is for suction, and the other is the return. We modified the tank connection plate and now we can use the manhole for both suction and return connections.

Here is one of the 130' diameter tanks we degassed. We did 3 tanks like this one at this tank farm. The floating roof on these tanks was at the low position about 4.5 feet above the floor. The volume of the tank under the floating roof is about 59,700 cubic feet. The gasoline vapor in the tank vapor space was very concentrated. The oxygen was only 17% in the tank when we started.

The job took 7 hours from start to finish and we recovered 275 gallons of gasoline. The gasoline was put in drums and the facility later transfered it back to a storage tank, completing the loop for recycling.

Here is the system in operation. The condenser takes the vapors from the storage tank and chills them until they condense back to liquid. On this job we recovered about 6 drums of gasoline. The amount recovered is dependent on several things:
Amount of time since the tank was taken out of service.
Volume of the tank vapor space.
Temperature of the vapor.
Volatility of the vapor.
Concentration in the tank.

Here is PURGIT equipment set up for vapor control on a tank barge at a shipyard. The suction and return lines are going out to the right. In this photo, we are degassing an ethylene dichloride (EDC) tank barge. We have also controlled perchloroethylene, methylene chloride and trichloroethylene in barges and shore tanks. The condensate is recovered and deposited in containers for recycling.

Condensing is much better for chlorinated solvents because combustor devices make undesirable by-products including acid in the exhaust gas. Combustion devices may have to scrub the exhaust to remove pollutants. Scrubbing makes hazardous waste.

This equipment is excellent for gasoline and hydrocarbons because it can handle the high concentration of the vapor space in those tanks. The condenser can handle 600 or more cubic feet per minute of vapor flow. That is much better than the flow rate of small combustors pulled behind pickup trucks. In fact, the condenser may be 10 times faster than small combustors and perhaps 15 times faster than the IC engine devices.

This photo shows the suction and return lines going to the tank barge. By pioneering the closed loop system PURGIT can degas a tank without opening the tank. One advantage of the closed loop system is that we do not suck in air during the vapor control That means that we do not create a flammable condition in the tanks. All combustion devices must suck in air, closed loop condensers do not need to do that. Air in the tank would create a flammable condition in the tanks if there is sufficient VOC gas, and there almost always is, since vapor control would not be necessary otherwise.

This tank barge, like many chemical barges, has a vapor return line system. If the barge did not have a return line, we would run a return line to each tank. On some tanks we have run more than 200' of suction and return line.

This barge is approx 22,000 bbl capacity total, divided into 6 cargo tanks. It took a little over 12 hours to complete the job on this big barge. We pulled vapors from the liquid line which goes to the bottom of each cargo tank and returned through the vapor system which returns to the top of the tank. Each tank was done one at a time.

For inland barges, the standard barge is called a 'jumbo'. It is 195' x 35' and holds about 10,000 to 11,000 bbl of cargo. The exact amount is dependent on the specific gravity of the cargo. Barges are limited to a draft of 9' (approximately) and so the quantity is driven by the weight of the cargo. These barges usually have 3 cargo tanks, but can have more. They are usually made of carbon steel. Sometimes the tanks are coated with special tank coating to protect the cargo. Very few are made with SS clad plate.

The next larger size barge is in the range of 22,000 bbl. And the largest standard size is in the range of 30,000 bbl.

Ethylene dichloride condensed in the PURGIT low temperature condenser and transfered to this tote. Approximately 225 gallons of EDC condensate was recovered on this job. Very little water was recovered on this job which indicates that the tanks were padded with nitrogen gas. There wasn't enough water to cover the top of the EDC.

The collected condensate is relatively pure since it is collected from the gas phase in the vapor space of the cargo tank. It appeared to be water-white, clean and pure in the container. The cargo stripped from the tank was off-color, so the recovered cargo was more pure. It could easily be returned to the commercial market.

June 2007, completed a vapor control project on a 11,000 bbl tank barge last containing methylene chloride. Recovered 4,000 pounds of MEC condensate from the barge tanks in about 6 hours. The condensate filled the totes you see on the left. EDC has a vapor pressure of almost 14 lbs and it is hard to control with activated carbon. It cannot be burned unless the exhaust is scrubbed. By condensing the vapors, the condensate can be recycled. No pollution.

The job took about 6 hours of condenser time.

Clean, water white condensed MEC

June 2007. A tank barge last transported chloroform in the tanks. The barge holds 10,474 bbl capacity. We estimate the concentration in the tanks at about 30% by volume (300,000 ppmv). The job took about 6 hours of condenser time.

Clean, water-white recovered chloroform.