Here are some vapor control, inerting and other interesting projects
completed by PURGIT since 1993. PURGIT references available on request. www.purgit.com
Anhydrous ammonia storage tank – Gassing up – PURGIT has vaporizers for making ammonia gas when tanks are being started up. We have hot water vaporizers, steam vaporizers and fin-fan ambient vaporizers for classified areas. On a recent job we used 2 vaporizers to increase flow rate and we successfully vaporized 2 tank trucks per day. That allowed the customer to charge his tank quickly.
Anhydrous ammonia storage tank – Decommissioning – PURGIT has gas flares for ammonia and nitrogen gas for tank inerting. We have the experience and procedure to safely remove ammonia from tanks.
EDC – ethylene dichloride. No other system is more effective degassing EDC tanks than PURGIT. We have controlled EDC vapor emissions from fixed roof tanks and floating roof tanks and barges and remediation projects for years. The best thing about our process is that we do not make hazardous waste. The EDC that we recover is recovered intact and can be reprocessed or sold as cargo. We have the only high capacity mobile process that has empirical evidence of the recovered chemical.
Ammonia storage tanks. PURGIT supplied an ammonia flare and personnel to degas a low pressure liquid ammonia storage tank. PURGIT supplied nitrogen gas to displace the ammonia to the flare. On completion of the degassing phase we again purged the tank with nitrogen gas to remove the air and then supplied an ammonia vaporizer to recondition the tank with ammonia gas so it could be reloaded with ammonia liquid.
Ammonia tank barges. PURGIT has an ammonia flare with a blower. The blower allows us to remove the ammonia gas faster when the tank pressure is low, a common condition during the pressure swing process. With the blower, PURGIT can finish the job much faster, saving the customer money.
Vapor control on chemical tank barges. Cargoes such as: chloroform, propylene dichloride, methylene chloride, gasoline and many other hydrocarbons. We are the method of choice when chlorinated cargoes are controlled because we do not make hazardous waste. Our system condenses the tank gas so that it can be recycled.
Vapor control with our proprietary condenser system on a 150′ external floating roof tank. This tank had BTX (benzene, toluene, xylene mixture) and needed to be cleaned for inspection and repair. We began condensing just as soon as there was a vapor space under the floating roof. In the course of the job we recovered about 13,348 gallons of condensate that otherwise would have been burned. Burning and combustion are a waste of valuable resources.
Ammonia vaporizer service at a methanol/ammonia manufacturing plant in Beaumont. We supplied an ammonia vaporizer to flood the tank with ammonia gas as part of the conditioning process. The customer was recharging the tank with liquid ammonia and needed to flush the nitrogen gas out of the tank. We also supplied ammonia pumps to transfer liquid ammonia.
Ammonia tank flaring and conditioning. PURGIT supplied a flare to burn ammonia vapors on a 130′ dia storage tank so that it could be opened for inspection. Once it was repaired, we supplied our nitrogen tanker and nitrogen vaporizer to purge the air out of the tank, then we supplied our ammonia vaporizer to condition the tank by filling it with ammonia gas. It was then refilled with NH3 liquid.
Chemical plant pipeline work. PURGIT assisted a large chemical plant, near Chocolate Bayou, south of Houston as they conditioned an ammonia pipeline and a propylene pipeline.
Gasoline tank at Convent, LA PURGIT degassed a floating roof gasoline tank with our condenser equipment. The tank was 110′ diameter and we controlled the vapors as the tank was washed with water. This combination of techniques cleared the LEL to under 50% in 2 days.
Chemical tank in Deer Park TX PURGIT condenser recovered 3,165 gallons of gasoline additive from the vapor space of a 140′ dia floating roof storage tank. The owner washed the tank while we were degassing.
Ethylene dichloride storage tank in Lake Charles. PURGIT condensed EDC vapors to de-contaminate a large tank for inspection and repair. We recovered many hundreds of gallons of EDC for recycling.
Vapor control on tanks and barges in 2010. PURGIT used the condenser equipment to degas many barges with cargoes like: EDC, chloroform, methylene chloride, etc.
7 gasoline storage tanks at a gasoline loading terminal. PURGIT degassed all the cargo tanks at a facility in north Houston that was closing.
Vapor control on a 110′ dia ethylene dichloride (EDC) tank This tank in Deer Park TX has an internal floating roof at about 3.5′. We were called to degas the tank per TCEQ regulations. But we did better than that, because we did not have emissions and we recovered 750 gallons of EDC from the tank vapor space. In addition, we maintained vapor control while the tank was water washed. The tank vapor space was saturated at the start and we reduced the EDC level way below the TCEQ rules. Circulated the tank vapor in our proprietary method (patent applied for) to maximize recovery and eliminate dead air pockets in the tank vapor space. By circulating the tank vapors we maintained a completely closed system without any discharge to the outside air.
Vapor control on a 120′ dia gasoline tank that has a floating roof at 6′ to meet TCEQ regulations. In just 9 hours, start to finish we completed the vapor control process. The tank was approximately 100,000 ppmv by volume concentration when we started and it was 29,880 ppm of VOC on completion. (Note: 34,000 ppmv is the TCEQ max specification, so we easily met the state rules.) We circulated 176,000 cu/ft of vapor through the tank in our proprietary closed loop system (patent applied for) to get the tank contents to meet the state specifications. No vapors were released and all the condensate recovered from the condensers was recycled.
Vapor control on a 85′ dia. gasoline tank with a floating roof at 7.5′ to meet TCEQ regulations. In just 6 hours start to finish we completed the vapor control process. The tank was approximately 80,000 ppmv by volume concentration when we started and it was 10,791 ppm of VOC on completion. (Note: 34,000 ppmv is the TCEQ max specification, so we easily met the state rules.) We circulated 88,000 cu/ft of vapor through the tank in our proprietary closed loop system to get the tank contents to meet the state specifications. No vapors were released and all the condensate recovered from the condensers was recycled.
Vapor control on a 14,500 bbl fixed roof tank that last contained epichlorohydrin at a tank farm. Controlled the vapors to 290 ppmv. The facility permit required them to get under 1,000 ppmv. We circulated the tank vapors through the condenser and easily met the Texas Commission on Environmental Quality rules for open venting.
Vapor control on a 14,500 bbl fixed roof tank that last contained dichloropropene at a tank farm. Circulated tank vapors through the condenser to reduce the tank vapor concentration to under 1,000 ppmv. The tank could then be washed to the facility water treatment system and by using the condenser system no chlorinated solvent was sent to the flare. Flares make hazardous waste when they burn chlorinated solvents and that makes a regulation nightmare. The PURGIT system makes no hazardous waste. On this job we recovered 65 gallons of Telone for recycling. Job completed in under 9 hours.
Vapor control on a 8,500 bbl fixed roof tank that last contained dichloropropene at a tank farm. Circulated tank vapors through the condenser to reduce the tank vapor concentration to under 1,000 ppmv. The tank could then be washed to the facility water treatment system and by using the condenser system no chlorinated solvent was sent to the flare. Recovered 145 gallons of Telone for recycling. Job completed in 8 hours.
Vapor control on a 138′ dia floating roof tank with 4.5′ under the floating roof. Job completed in under 5 hours. Reduced vapor concentration from 7% to about 2,500 ppmv according to customer meter, tank contents isooctane.
Vapor control on a 100′ dia floating roof tank with 6.5′ under the floating roof. This tank last contained light straight run (similar to gasoline) with a 14 psi vapor pressure. It was pumped out immediately before the vapor control started. Suction and return vapor hoses were connected to the tank and the condenser was started just after 7:00 in the morning. By 13:00, just 6 hours later, we completed 4 volumes and recovered 495 gallons of pure light straight run condensate that was put back in an adjoining tank. There is no combustion system on the planet that can do that! No air was added to the tank vapors and they never became explosive during our vapor control. The owner checked the tank with an IR light and found zero VOC emissions during the process. The value of the 495 gallons of recovered gasoline is greater than the cost of the input energy (12,000 pounds of liquid nitrogen and 20 gallons of diesel) to the vapor condenser.
Vapor control on 90′ dia. floating roof tank with 6.5′ under the floating roof. This tank last contained gasoline with a 10 psi vapor pressure and it was pumped out immediately before the vapor control started. Suction and return vapor hoses were connected to the tank and the condenser was started at 9:20 in the morning. By 14:35 we completed 4 volumes and recovered 215 gallons of pure gasoline that was put back in an adjoining tank. By observed measurement on a MSA(R) Tankscope(R) the tank vapors measured 24% by volume when we started. At the end, just over 5 hours later, the tank vapors were flirting with breaking into the LEL range, so they were under 2%. Note: 2% is 20,000 ppm. That is quite a reduction. We stopped there only because we fulfilled the regulatory requirements. This tank was never put in an explosive condition by adding air. All combustion systems would have pulled air in and created an explosive mixture in the tank PURGIT does not. On this job the recovered condensate just about covered the cost of input materials.
Vapor control on 100,050 bbl cap tank. This tank was designed for 15 psi. It had isoprene and was being cleaned for maintenance. When we started vapor control, the tank had approx. 8 psi. We recovered 5,000 gallons of isoprene and put the recovered material back in a pipeline segment. The PURGIT system put nitrogen gas back in the tank to maintain slight pressure on the tank at all times. PURGIT does not need to pull air into a tank during cleaning because it uses a closed loop, and condensers can process inerted vapors, no oxygen required.
Vapor control on a gasoline tank with floating roof. Vapor control on 2 tanks that had approx. 40% concentration gasoline vapors by volume. Condensed vapors and collected the gasoline in drums for recovery at the tank farm. Recovered 500 gallons of gasoline.
Ammonia pipeline vapor control. Vaporized ammonia liquid from pig traps, sent the gas to the ammonia flare. Connected the knock-out tank to the pipeline so liquid would not carry over to the flare.
Pipeline vapor control. Near Denver, Colorado and Pasadena, TX PURGIT set up a mobile flare, knockout tank, vaporizer, blower, hoses and other equipment to safely degas a pipeline with approx. 16,000 pounds of isobutane liquid. Equipment was moved from one pig trap to another pig trap to control emissions at those sites.
On a LP pipeline we pulled a partial vacuum which caused the LP to volatilize making it easy to flare.
Moisture control. By pulling a partial vacuum on a pipeline, the moisture will volatilize and can be removed with less nitrogen purging.
Chlorinated solvents. Condensed chlorinated solvents during tank barge cleaning. Almost too many to count. Methylene chloride, perchloroethylene, ethylene dichloride, etc. Barge sizes from 10,000 to 30,000 bbl cap.
Vaporizer service. Furnished a vaporizer to provide approximately 85,000# of CO2 gas for a local chemical facility. Operated the vaporizer for two 24 hour periods and delivered the gas at 100 deg. F.
Emergency vaporizer service. At a refinery in Lake Charles, PURGIT vaporized ethylene and burned the gas in 2 John Zink vapor combustion devices.
Tank vapor control & recovery. PURGIT performed cryogenic vapor control: to clean 5 gasoline tanks in Perth Amboy, NJ. The process recovered over 40 barrels of gasoline. Because of the unique nature of the PURGIT(R) condenser we minimized NOx emissions to zero and had no source of ignition in the tank farm.
Vapor control on a: 5,000 bbl MTBE (methyl tertiary butyl ether) fixed roof tank in Port Neches, TX the final LEL reading was 0.05% – even though the tank had 2′ of catalyst on the floor.
A spherical tank in Texas City contained aldehyde. PURGIT cleaned the tank without adding any air or moisture. About 35 gallons of aldehydes were condensed into drums.
Barge transfer. In New Orleans, PURGIT has provided vapor control at a tank farm that handles chlorinated solvents during barge loading and tank cleaning.
Rail cars. PURGIT conditioned 7 rail cars for a Houston area chemical company. The job involved drying the cars with heated nitrogen gas. A device called a Lectrodryer(R)was used to measure the humidity in the rail cars to a dew point of -30 deg. F.
Emergency rail car service. At a refinery in Paducah KY, PURGIT burned ethylene with our mobile flare to allow cargo to be transferred between 2 rail cars. We also furnished the 3″ transfer hose and the flare.
Inert gas service. PURGIT maintained an inert atmosphere in a rail car at a Houston rail siding over a 2 day period so that a moisture and static sensitive cargo could be safely loaded.
Equipment maintenance. Expensive machinery needed a small nitrogen flow to keep air and moisture out prior to shipment. Maintained nitrogen flow for 1 month at 2 cubic feet per hour.
Various jobs from hundreds of completed projects:
A chemical storage tank had layer of hydrocarbon floating causing air emission problems. Another contractor tried to remove the hydrocarbon by dropping a hose in the tank and sucking the top layer, but it was so in-effective the owner called PURGIT. We set up our condenser system on the tank. As the VOC flashed into the vapor space we condensed it back to liquid and it was removed from the tank. Just like distilling fine whiskey. We recovered hundreds and hundreds of gallons of gasoline VOC and put it in totes for recycling. And that brought the tank back into compliance. Our vapor control operation did not disturb the tank loading and unloading which continued as normal.
150,000 bbl internal floating roof storage tank / Chloroform A low temperature condensation system was perfect for this job. The vapors from the tank were drawn through the condensation coil with a high performance blower. The tank vapors were dropped to -35 or less and the chloroform condensate that collected in the bottom of the storage tank was transferred to drums. Condensation is better than combustion on chlorinated solvents because it does not produce hydrochloric acid as a byproduct, and there is zero NOx. The fact that PURGIT has no flame or unprotected source of ignition is and was a significant benefit of the condensation system working in a tank far.
130′ diameter floating roof tank Gasoline storage tanks near a school needed to be cleaned for routine maintenance. PURGIT was called to set up an internal combustion engine vapor control device in advance of the tank cleaners. This device was selected for its compact design, quick setup and safety features. The tank vapor space under the floating roof was turned 4 times to meet the Texas emission control regulations. The volume of vapor moved was measured with a turbine meter.
Water treatment system Benzene in waste water created unacceptable levels of benzene in the working areas of the treatment facility. To overcome this problem, a tent was erected over the DAF and associated tanks. Then PURGIT set up a non sparking blower to suck the benzene out and push it to an enclosed flare. The level of benzene outside of the tents was kept to very low levels and the level of benzene pushed to the flare was over 1,000 ppm.
200,000 bbl external floating roof storage tank / Pygas Levels of benzene in the pygas made vapor control especially important. Using the full PURGIT system, inert gas bubbled into the bottom of the tank as the blower moved the vapor to the combustion device. This was done to create the safest and most efficient working environment.
150,000 bbl. internal floating roof storage tank / Gasoline At the largest commercial tank farm in Houston set up the enclosed flare. There was a high concentration of gasoline vapor in the tank as a result of the heat of the July sun in Texas. A blower capable of handling flammable vapors moved the vapors from the tank to the flare. A detonation arrester and water trap added levels of safety. The operation was completed in less than 12 hours meeting TCEQ regulations.
55,000 bbl. internal floating roof tank / Vinyl acetate At a La Porte, TX tank farm set up the enclosed flare to burn VOC emissions from the tank. Once TCEQ regulations were met, the tank was opened and cleaned.
24″ pipeline / Crude oil At a Pasadena, TX pipeline terminal set up the enclosed flare to burn hydrogen sulfide gas generated when the pipeline was purged with nitrogen. The PURGIT blower drew the H2S gas out of frac. tanks and kept it from escaping to the surrounding neighborhood.
10,000 bbl. capacity / 3 tank, chemical barge / Hexane. Used the PURGIT system in the #1 cargo tank. Achieved 95% removal of hexane with 1.1 volume of CO2. By displacing the Hexane out of the cargo tank with carbon dioxide and routing the tank vapors to an engine vapor control device, the barge was cleared of the hexane vapors and very little supplemental fuel gas was needed.
15,000 bbl. capacity / 4 tank, (LPG) tank barge / Crude butadiene. De-pressured 4 tanks from 90# to 12# pressure. Nitrogen from a previous discharge remained in the tanks as a non condensable gas which kept the barge from loading. PURGIT met the barge in Port Lavaca, and safely flared off the nitrogen pressure at the dock without having to move the barge to another port.
50,000 bb. capacity / 5 tank, LPG ship / Propylene. Flared 5 tanks to remove nitrogen gas. Nitrogen gas had been used to inert the tanks and remove moisture and oxygen. But the nitrogen had to be removed to allow the ship’s refrigeration compressors to work properly. Assisted Intership Services to prepare the tanks by gassing up with propylene and flared the nitrogen and propylene. PURGIT met the barge in Lake Charles, and efficiently removed the pressure at the dock without the ship having to go to sea to vent or leave the dock.
Many 22,000 bbl. capacity Anhydrous Ammonia tank barges. De-pressured tanks and purged tanks with nitrogen. Tanks on these barges were due for an inspection. The customer wanted to do tank cleaning at a yard that does not have a flare. PURGIT sent it’s mobile flare to Louisiana to do the vapor control. PURGIT provided nitrogen services. After the tanks were repaired we assisted the owners with conditioning tanks with nitrogen to remove air, assisted customer to flood tanks with ammonia, flared nitrogen until ammonia is at proper level.
15,733 bbl. capacity 4 tank LPG pressure tank barge containing butane. Assisted in transferring remaining cargo to tank truck. Used the PURGIT method of emission control to displace the butane with carbon dioxide. Burned the butane in the PURGIT open flare. Reduced butane in tanks from saturated to 90% of the LEL with 3.2 volumes of CO2.
22,000 bbl. capacity tank barge with 8 tanks / Bunker oil Inerted all tanks for hot work. Minor deck items needed to be welded. Cleaning the tanks would have been expensive, so the vessel owner called PURGIT to inert, saving thousands of dollars in cost.
200,000 bbl external floating roof storage tank / Crude oil Refinery personnel wanted to control the release of VOC during tank cleaning at a refinery site. Mobilized the internal combustion engine along with hose, detonation arrester, propane cylinders, etc..
This page could have 1,000 entries or more, so we just picked some of the more interesting or representative jobs. Thank you for reviewing our case history.