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CHAPTER 11.2BELCO EDV WET SCRUBBING

SYSTEM: BEST AVAILABLECONTROL TECHNOLOGY

(BACT) FOR FCCU EMISSION CONTROL

Edwin H. Weaver and Nicholas ConfuortoBelco Technologies Corporation

Parsippany, New Jersey

THE FCCU—A UNIQUE PROCESS FOREMISSIONS CONTROL

The control of particulate and SO2 emissions with wet scrubbing systems is not uncom-mon. However, the control of these emissions, combined with the special needs andrequirements of the fluid catalytic cracking unit (FCCU) process, indeed makes this a spe-cial process for wet scrubbing systems.

Uncontrolled particulate (catalyst) emissions from this source vary depending on thenumber of stages of internal and external cyclones. Although cyclones are effective in col-lecting the greater constituent of catalyst recirculated in the FCCU regenerator, the attri-tion of catalyst causes a significant amount of finer catalyst to escape the cyclone systemwith relative ease. Typically, emissions will range from 3.0 to 8.0 lb per 1000 lb of cokeburn-off.

Sulfur emissions in the form of SOx (SO2 and SO3) from the regenerator vary signifi-cantly depending on the feed sulfur content and the FCCU design. In the FCCU reactor,70 to 95 percent of the incoming feed sulfur is transferred to the acid gas and product sidein the form of H2S. The remaining 5 to 30 percent of the incoming feed sulfur is attachedto the coke and is oxidized into SOx which is emitted with the regenerator flue gas. Thesulfur distribution is dependent on the sulfur species contained in the feed, and in particu-lar the amount of thiophenic sulfur. SO2 can range from 200 to 3000 parts per million dryvolume basis (ppmdv), whereas SO3 typically varies from an insignificant value to a max-imum of 10 percent of the SO2 content.

The FCCU application presents the additional requirement that in order to match thereliability of the FCCU, the air pollution control equipment must operate on-line for 3 to

11.15

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5 years without interruption. It must be able to tolerate significant fluctuations in operat-ing conditions, withstand the severe abrasion from catalyst fines, and maintain operationthrough system upsets. The robust design of the wet scrubbing system must tolerate alloperations without requiring a shutdown. It is paramount that the operability of the air pol-lution control system be no less than that of the FCCU process.

CONTROLLED EMISSIONS—A TREND TOWARDLOWER LEVELS

By examining the trends of emissions regulations in the United States, a trend for bettercontrol of emissions from FCCUs can be established. The United States EnvironmentalProtection Agency (USEPA) established New Source Performance Standards (NSPS) foremissions from FCCUs for new or significantly modified units. A summary of this stan-dard is provided in Table 11.2.1. Additionally, a maximum achievable control technology(MACT) standard is in the final stages of promulgation. This standard, which is intendedto regulate the amount of hazardous air pollutants (HAPs) from the FCCU, essentiallyestablished the particulate emission level at the same level as NSPS, or 1.0 lb/1000 lb ofcoke burned.

The USEPA also has been aggressive in pursing enforcement actions against refinerswho, in its opinion, have significantly modified their facilities but avoided the NSPS reg-ulations. This has resulted in several consent decrees where a refiner has agreed to installpollution controls to mitigate the impact of any past modifications made to its facility.Refiners who have reached consent decrees with the USEPA include Koch Refining,British Petroleum, Motiva/Equilon/Shell, Marathon Ashland LLC, Holly Corporation,Premcor Refining, Conoco, and Murphy Oil. In many cases, the agreed-to emissions lev-els (25 ppm SO2 and 1. 0 lb/1000 lb of coke burned) are more restrictive than the NSPSregulations. Wet scrubbing systems are mandated for many of the facilities in the consentdecrees.

A PROVEN WET SCRUBBER DESIGN FOR THEFCCU PROCESS

The worldwide leading technology to control emissions from this process is BelcoTechnologies Corporation’s EDV wet scrubbing system. This wet scrubbing system con-trols particulate (catalyst dust), SO2 (sulfur dioxide), and SO3 (sulfuric acid mist) all in onesystem. Removal of relatively coarse particulate, which constitutes the majority of the par-

11.16 SULFUR COMPOUND EXTRACTION AND SWEETENING

TABLE 11.2.1 New Source Performance Standards for FCCU Regenerator Emissions

Pollutant FCCUs affected Emission regulation

Particulate All 1.0 lb/1000 lb Coke burn-off and 30% opacity

SO2 With add-on SO2 50 ppm SO2 or 90% reduction, whichevercontrol device is least stringent

Without add-on SO2 9.8 lb SO2/1000 lb coke burn-offcontrol device

Or 0.3% Sulfur in feed (% by weight)

BELCO EDV WET SCRUBBING SYSTEM: BEST AVAILABLE CONTROLTECHNOLOGY (BACT) FOR FCCU EMISSION CONTROL



BELCO EDV WET SCRUBBING SYSTEM: BACT FOR FCCU EMISSION CONTROL 11.17

ticulate from the FCCU, is accomplished in the absorber vessel where caustic soda(NaOH) or other reagents are utilized to absorb SO2 and discharge it in the form of a sol-uble salt. Fine particulate control and significant reduction of SO3 in the form of sulfuricacid mist are accomplished in devices known as filtering modules. Excess water dropletsare removed in highly efficient droplet separators. An EDV wet scrubbing installation inTexas is shown in Fig. 11.2.1. Another U.S. Gulf Coast refinery EDV wet scrubber is illus-trated in Fig. 11.2.2.

The flue gas from the FCCU enters the spray tower, where it is immediately quenchedto saturation temperature. Although the flue gas normally enters the wet scrubber afterpassing through a heat recovery device, the system is designed so that it can accept fluegas directly from the FCCU regenerator at the temperature at which it exits the FCCUregenerator. The spray tower itself is an open tower with multiple levels of spray nozzles.Each level of nozzles can have one or multiple nozzles depending on the diameter of theabsorber vessel. Since it is an open tower, there is nothing to clog or plug in the event ofa process upset. In fact, this design has handled numerous process upsets where more than100 tons of catalyst has been sent to the wet scrubber in a very short period of time. Anillustration of this spray tower is provided in Fig. 11.2.3.

FIGURE 11.2.1 EDV wet scrubbing system in Texas.




In the spray tower, coarse particulate is removed through the simple process of liquidfrom the spray nozzles impacting on the particulate. Reduction of SO2 is accomplished byadding reagent, usually caustic, to the liquid being circulated in the absorber vessel.Assuming caustic is used, the SO2 reacts with caustic to form sodium sulfites, some ofwhich oxidizes to sodium sulfates. Both of these are dissolved solids.

These nozzles, used for both the quench and the spray tower, are LAB-G nozzles. Theyare a unique design and a key element of the system. They are nonplugging, constructedof abrasion-corrosion-resistant material, and capable of handling high concentrated slur-ries. Unlike in most nozzle designs, this nozzle has a large opening that cannot plug and isdesigned to operate at low liquid pressure, both important factors in long-term life. As pre-viously noted, these nozzles remove coarse particulate by impacting on the liquid droplets.They also spray the reagent solution to reduce SO2 emissions. By design, they produce rel-atively large water droplets, which prevent the formation of mist and the need for a con-ventional mist eliminator that will be prone to plugging. This is unique in wet scrubbingsystem designs as any other design that uses a nozzle which produces mist size waterdroplets will require a mist eliminator to eliminate these droplets. Mist eliminators have


FIGURE 11.2.2 EDV wet scrubber at U.S. Gulf Coast refinery.




plugged in the presence of catalyst. This nozzle is illustrated in Fig. 11.2.4 and is shownspraying liquid in Fig. 11.2.5.

Upon leaving the spray tower, the saturated gases are directed to the EDV filteringmodules for removal of the fine particulate. This is achieved through saturation, conden-sation, and filtration. Since the gas is already saturated, condensation is the first step in thefiltering modules. The gases are accelerated slightly to cause a change in their energy state,and a state of supersaturation is achieved through adiabatic expansion. Condensation


FIGURE 11.2.3 EDV absorber vessel/spray tower.





FIGURE 11.2.4 Absorber vessel spray nozzle.

FIGURE 11.2.5 Absorber vessel nozzle spraying liquid.




occurs on the fine particulate and acid mist. This causes a dramatic increase in size of thefine particulate and acid mist, which significantly reduces the required energy and com-plexity of its removal. A LAB-F nozzle located at the bottom of the filtering module andspraying upward provides the mechanism for the collection of the fine particulate and mist.This device has the unique advantage of being able to remove fine particulate and acid mistwith an extremely low pressure drop and no internal components which can wear and bethe cause of unscheduled shutdowns. It is also relatively insensitive to fluctuations in gasflow. This device is illustrated in Fig. 11.2.6.


GAS IN

WATERIN

GASIN

WATEROUT

CONDENSATION

FILTERING SPRAY

FIGURE 11.2.6 Filtering module.




To ensure droplet-free gas, the flue gas then goes through a droplet separator. This isan open design that contains fixed spin vanes that induce a cyclonic flow of the gas. As thegases spiral down the droplet separator, the centrifugal forces drive any free droplets to thewall, separating them from the gas stream. This device has a very low pressure drop withno internal components which could plug and force the stoppage of the FCCU. This deviceis illustrated in Fig. 11.2.7.


GAS IN

GAS OUT

SPIN VANE

WATEROUT

FIGURE 11.2.7 Droplet separator.




ALTERNATE CONFIGURATIONS

One of the great benefits of the EDV wet scrubbing system’s modular design is that thesame proven modules can be arranged in many different configurations to fit a specific siterequirement. The system can be provided in an upflow configuration to reduce plot space.Several of these designs have been sold to date.

The system can also be provided in a jet ejector configuration to offset pressure dropacross the system. This configuration is marketed by Belco as its NPD design (whichstands for no pressure drop).

The major advantage of the Belco’s NPD configuration over any other jet ejector con-figuration is that although it utilizes the same proven jet ejector units as the competition,the BELCO approach does not rely exclusively on the jet ejector to achieve the requiredefficiency. Belco places the jet ejectors after its primary scrubbing module (the quench andspray tower). Therefore, by the time the gas reaches the jet ejectors, it has already beencleaned of most of the particulates and SO2. The jet ejectors are used only for polishingand for developing the required draft. This provides higher efficiencies than other jet ejec-tor designs; and by placing the jet ejectors on the clean end of the scrubber, the wear andmaintenance typically associated with jet ejectors are greatly reduced.

SCRUBBER PURGE TREATMENT

Assuming that a sodium-based system is used, purge from the wet scrubbing system con-tains catalyst fines as suspended solids, and sodium sulfite (NaSO3) and sodium sulfate(NaSO4) as dissolved solids. The purge treatment system removes the suspended solidsand converts the sodium sulfite to sodium sulfate to reduce the chemical oxygen demand(COD) so that the effluent can be safely discharged from the refinery.

To remove the suspended solids, the purge treatment system contains a clarifier to sepa-rate the suspended solids and a filter press or dewatering bins to concentrate the solids intoa filter cake which is cohesive and can be readily disposed of. The scrubber purge enters theclarifier from a deaeration tank. The solids settle out in the clarifier and are removed fromthe clarifier in the underflow. The underflow from the clarifier is sent to a filter press or dewa-tering bins where the excess water is removed. The solids are sent to disposal while the wateris returned to the clarifier. The effluent is then sent to the oxidation towers.

The oxidation system consists of towers where air is forced into the effluent to oxidizethe sodium sulfite to sodium sulfate. Effluent from the oxidation towers, which is nowcleansed of catalyst (suspended solids) and has a low COD level, can be processed in therefinery wastewater system or possibly directly discharged from the refinery. A typicalpurge treatment system that employs a filter press is illustrated in Fig. 11.2.8.

REAGENT OPTIONS

Historically, most wet scrubbing systems on FCCUs have utilized caustic (NaOH) as thereagent. Caustic is readily available in refineries, is easy to handle, and has no solid reac-tion by-product. These systems have proved to be very effective and reliable, with contin-uous operation in excess of 5 years while handling all upset conditions that can occur.

With the escalating cost of caustic and the need to reduce the total liquid effluent fromthe system, some refiners are using soda ash (Na2CO3) as a reagent. The primary differ-





ence between soda ash and caustic is that soda ash is delivered as a bulk solid and mixedinto a liquid on site. However, it has the advantage of having no chlorides. High concen-trations of chlorides attack the 316L stainless steel material used in the wet scrubber, sothe level of chlorides must be controlled. With no chlorides from the soda ash, the dis-solved solids concentration in the wet scrubber can be increased, thus reducing the amountof liquid that must be purged. Depending on the strategy for liquid effluent control, a lowdischarge volume is very important.

In a typical system, soda ash is delivered in dry bulk form. As the soda ash is blowninto the storage silo from the truck, an eductor-type wetting system is used to mix the drysoda ash with water and slurry the soda ash. Soda ash liquor is drawn from the top third ofthe tank and pumped to the wet scrubbing system, where some of the soda ash is used bythe wet scrubber. The amount used by the wet scrubber is based on pH control. Theremaining soda ash is returned to the storage tank. This ensures that there is a continuousflow both to and from the storage tank. A typical soda ash delivery system is illustrated inFig. 11.2.9.

Regenerative wet scrubbing systems are also gaining popularity. These systems haverelatively low operating costs and have no liquid effluent discharge. In a typical regenera-tive system, the buffer is circulated in the EDV wet scrubbing system where it reacts withand removes the SO2 in the flue gas. The buffer, rich in SO2, is then sent to a regenerationplant.

Before entering the regeneration process, the SO2-rich buffer is heated in a series ofheat exchangers. The first heat exchanger utilizes the heat from the regenerated bufferbeing returned to the absorber vessel, while the second heat exchanger utilizes steam. Afterbeing heated, the buffer is sent to a double-loop evaporation circuit. These circuits use aheat exchanger, separator, and condenser to separate water and SO2 from the buffer. Buffer,which is free of SO2, is sent to a mixing tank, while the evaporated water and SO2 are sentto a stripper.


PURGEWATER

FLOCCULENTCLARIFIER STORAGE

TANK

UNDERFLOWPUMP FILTER

CAKE

AIR BLOWEROXIDATION TOWERS

EFFLUENTDISCHARGE

MAKEUPWATER

FILTER PRESS

FIGURE 11.2.8 Typical purge treatment system.




In the stripper/condenser, the gas is cooled by counterflowing condensate from the con-denser. The temperature of the SO2-rich gas that leaves the condenser is used to control theamount of cooling medium that must be sent to the condenser. Condensate from the strip-per is returned to the buffer mix tank. The SO2-rich gas, containing at least 90 percent SO2with the remainder being water, is ready for transport to a process unit. In the refinery, thisnormally would be the sulfur recovery unit (SRU), where it would be converted to ele-mental sulfur. Also, this SO2 that is sent to the SRU can help debottleneck the SRUprocess, especially if it is running close to capacity.

At periodic intervals, a quantity of concentrated buffer is bled from the evaporation cir-cuit along with some condensate from the stripper. This is done to maintain a constant con-centration of sodium phosphate in the buffer system. Sulfates are removed from this bleedstream through a patented process utilizing a series of filters. The filtrate collected in thisprocess is the only waste generated in the process. This is a very small quantity, repre-senting only 1 to 2 percent of the sulfur removed in the process. Disposal of this waste isthrough normal solid disposal techniques. The liquid from the filtrate process containsbuffer and is returned to the buffer mix tank.

In the buffer mix tank, small quantities of buffer are added to make up for the bufferlost in the process, typically less than 2 percent. This regenerated buffer is then returned tothe absorber vessel for removal of SO2 from the flue gas.

Although lime-based systems are very common outside of refineries, they have notbeen popular for controlling FCCU emissions. This is primarily due to three factors. First,the buildups that occur in any lime-based scrubbing system necessitate the cleaning of thesystem every 2 years or less. This is not compatible with the turnaround cycles of 3 to 5years for an FCCU. Next, the solids handling equipment associated with lime systems isextensive, resulting in high labor requirements and maintenance. Finally, a relatively hugequantity of gypsum is produced as a by-product. This is another large materials handlingand disposal issue.


CAUSTIC

WATER PUMPS

SODA ASH

WATERSUPPLY

TO SCRUBBER

FIGURE 11.2.9 Typical soda ash delivery system.




REAGENT SELECTION ECONOMICS

To illustrate the economic impact on the various design options available, a medium-size(30,000-BPSD) FCCU with a high (1800-ppm) SO2 level was selected for evaluation pur-poses. This case uses caustic (NaOH) as the reagent and has the wet scrubbing system andpurge treatment unit previously described. To compare the different options available, abase capital investment cost for this option is assigned with a level of 1. All additional cas-es will be evaluated against the capital cost of this option and a relative difference assignedto each case.

Operating cost is also a very important evaluation factor. Several factors were evaluat-ed for operating costs. These include reagents (caustic at $300/ton, soda ash at $150/ton,phosphoric acid at $890/ton), power at $0.05/kWh makeup water at $0.02/m3, liquid efflu-ent discharge at $0.04/m3, steam usage at $0.57/1000 kg, solids disposal at $44/1000 kg,and operation and maintenance costs per year at 2 percent of the capital investment. Withthe caustic scrubber being the base case, this option has been assigned an operating costlevel of 1. However, it is interesting to see how the operating costs are distributed betweenthe various factors. This is illustrated in Fig. 11.2.10. As can be seen, by far the major oper-ating cost is the reagent. Power and operating and maintenance costs are relatively minorwhile the other costs are an extremely minor percentage of the total operating cost.

As illustrated in Fig. 11.2.11, the capital cost of the system increases as additionalequipment is added. Since little additional equipment is required for a soda ash system,there is only a minor increase in capital cost over the cost of a caustic system. A soda ashscrubber with a crystallizer has a much higher increase in capital cost, primarily due to thecost of the crystallizer. Finally, the regenerative system has the highest capital cost, most-ly due to the cost of the regeneration plant.

Operating costs also vary greatly. A caustic system has the highest operating cost dueto the reagent cost. A soda ash scrubber has a lower operating cost, primarily due to low-er reagent cost. A soda ash system with a crystallizer has a cost near that of a caustic sys-tem, mostly due to steam needs and additional power requirements. However, this optionhas the added benefit of no liquid effluent discharge which can be very important in some


0

10

20

30

40

50

60

70

80

90

100

Caustic Power Makeupwater

Waterdischarge

Solidsdisposal

O & M

Perc

ent o

f op

erat

ing

cost

FIGURE 11.2.10 Distribution of operating costs in a wet scrubbing system.




situations. Finally, the regenerative system has the lowest operating cost, with reagentcosts only a small fraction of those of nonregenerative systems. It also has the benefit ofno liquid effluent discharge and has a by-product of SO2 which can be processed into ele-mental sulfur in the SRU. With the regeneration plant properly designed, the system canalso add scrubbers to other emission sources and process their buffer in the same regener-ation facility. This is a great advantage if multiple scrubber systems are being consideredor are required.

Another way to look at comparative system costs is to look at the equivalent cost perton of SO2 removed. The equivalent cost is determined by taking the system capital costand determining an annualized cost. The annualized cost is calculated based on an interestrate of 10 percent and a 15-year equipment life. Once the annualized cost is calculated, theyearly operating cost is added to it to reach a total annualized cost. Dividing this cost bythe tons of SO2 removed will result in an equivalent cost. The equivalent costs for the fouroptions considered are provided in Fig. 11.2.12.

The soda ash scrubber with a crystallizer has the highest equivalent cost while theregenerative scrubbing system has the lowest equivalent cost.

ACHIEVABLE EMISSIONS—A CASE HISTORY

As an example of the type of performance that can be achieved with a modern wet scrub-bing system, the installation of a new wet scrubbing system is examined. This wet scrub-bing system is installed on a new FCCU residual fluidized catalytic cracker (RFCC) witha design capacity of 10,500 BPSD. The RFCC was designed to process a variety of resid-ual feedstocks. The RFCC has two stages of internal cyclones in the regenerator. Also, aCO boiler was installed after the regenerator for the reduction of CO. To comply withNSPS for particulate and SO2 emissions, a wet scrubber was provided.


0.0% 50.0% 100.0% 150.0% 200.0%

Caustic scrubber

Soda ash scrubber

Soda ash scrubberwith crystallizer

Regenerative scrubber

Cost as % of caustic scrubber cost

Capital cost Operating cost

FIGURE 11.2.11 Capital and operating cost comparison.




The system was placed into operation in 1997. Over the first several months of opera-tion, the RFCC experienced multiple process upsets which resulted in as much as 20 to 30percent of the catalyst inventory being carried out of the regenerator and into the wetscrubbing system. The wet scrubber readily handled all these process upsets. The opera-tion of the scrubber was not interrupted. The system continued to operate, and the exces-sive solids were washed out of the system by overflowing the main scrubber recirculationtank to a tank where the solids could be settled out. These upsets also did not cause pre-mature wear of the nozzles.

To demonstrate compliance with environmental regulations, emissions testing was per-formed to verify the emissions performance of the system. Testing was performed both atthe inlet to the wet scrubbing system and at the stack. The results of these tests were excep-tional.

First, the testing at the inlet to the EDV wet scrubbing system demonstrated that thesystem was operating at higher than design values for gas flow and SO2 loading while hav-ing a lower than design loading for particulate. The flue gas flow rate was approximately20 percent over design on a mass basis. SO2 was approximately 3.1 times the design val-ue on a mass basis. However, the particulate was approximately 50 percent of the designvalue on a mass basis. A summary of the average inlet test values, compared to the systemdesign values, is presented in Table 11.2.2.

The performance of the system was excellent. SO2 was only a small fraction of thedesign outlet value. The mass outlet SO2 emissions were only 12 percent of the design val-ues, while the tested removal efficiency was 99.92 percent compared to a design efficien-cy of 97.90 percent. Particulate emissions were also very low. The mass emission rate wasapproximately 24 percent of the design value, while the tested removal efficiency was92.24 percent compared to the design removal efficiency of 83.70 percent. A summary andcomparison of these data are provided in Table 11.2.3.


0

100

200

300

400

500

600

700

800

900

1000

Caustic scrubber Soda ash scrubber Soda ash scrubberwith crystallizer

Regenerativescrubber

Equ

ival

ent c

ost $

/ton

SO2

rem

oved

FIGURE 11.2.12 Equivalent cost comparison of different wet scrubbing solutions.




A WEALTH OF EXPERIENCE

The EDV wet scrubbing system has presently been installed on more than 20 FCCUs witha total refining capacity of more than 1,000,000 BPSD. Many refiners have selected theEDV wet scrubbing system for multiple FCCUs within their system based on the reliabil-ity, ease of operation, durability, and satisfaction with the system design and performance.Additionally, more than another 200 EDV wet scrubbing systems have been installed inother non-FCC applications. Table 11.2.4 shows all EDV applications as of October 2002.

As the need to reduce emission levels continues to be an important focus, refiners willfocus on wet scrubbing solutions as a way to meet present and future needs, while allow-ing them the maximum flexibility in refinery feedstock selection and operation. As theyselect the vendor of choice, refiners will focus on experience, system reliability, quality ofservice, and the ability of the system to achieve today’s emissions consistently while hav-ing sufficient ability to be able to meet tomorrow’s requirement without major rework. Amodular-type design with the ability to meet or exceed all present requirements, such asthe EDV wet scrubbing system, and which can easily be upgraded as the future environ-mental demands on the refinery increase is a great benefit to a refinery struggling to deci-pher the future of its environmental requirements.


TABLE 11.2.2 Scrubbing System Inlet—Design and TestedConditions

Item Tested value Design value

Flue gas flow 312,628 lb/h 261,886 lb/h133,904 ACFM 106,644 ACFM

Flue gas temperature 483°F 550°FParticulate loading 0.064 gr/DSCF 0.178 gr/DSCF

38 lb/h 76 lb/hSO2 loading 1314 ppmdv 626 ppmdv

970 lb/h 313 lb/h

TABLE 11.2.3 Scrubbing System Emissions—Design and Tested Conditions

Item Tested value Design value

Particulate emissions 0.0047 gr/DSCF 0.029 gr/DSCF2.95 lb/h 12.39 lb/h92.24% removal efficiency 83.70% removal efficiency

SO2 emissions 1.0 ppmdv 13.1 ppmdv0.79 lb/h 6.55 lb/h99.92% removal efficiency 97.90% removal efficiency





TABLE 11.2.4 EDV Wet Scrubbing Installation List of FCCU Applications

Capacity,*Refining company Refinery location BPSD Reagent

1. Valero Refining Company Corpus Christi, Tex., USA 85,000 Caustic2. Coastal Westville, N.J., USA 50,000 Caustic3. Quakerstate/Pennzoil Shreveport, La., USA 10,500 Caustic4. Orion/TransAmerica Norco, La., USA 100,000 Caustic5. Formosa Petrochemical—1 Mai Liao, Taiwan 73,000 Caustic/MgO6. Formosa Petrochemical—2 Mai Liao, Taiwan 73,000 Caustic/MgO7. Essar Oil Limited Vadinar, India 59,500 Lime/caustic8. Indian Oil Corp. Limited Haldia, India 14,000 Caustic9. Motiva Port Arthur, Tex., USA 83,000 Caustic

10. Irving Oil Limited St. John, NB, Canada 70,000 Caustic11. Marathon Ashland Pet. LLC Robinson, Ill., USA 48,000 Soda ash12. Indian Oil Corp. Limited Barauni, India 26,500 Caustic13. National Oil Distribution Co. Messaieed, Qatar 30,000 Caustic14. Valero Refining Company Texas City, Tex., USA 60,000 Caustic15. TOSCO Refining Company Ferndale, Wash., USA 30,000 Caustic16. HPCL Visakh, India 20,000 Caustic17. Indian Oil Corp. Limited Gujarat, India (new FCC) 60,000 Caustic18. Indian Oil Corp. Limited Gujarat, India (existing FCC) 30,000 Caustic19. Marathon Ashland Pet. LLC Texas City, Tex., USA 43,000 Caustic20. AGIP Sannazaro, Italy 34,000 LABSORB21. Premcor Hartford, Ill., USA 30,000 Caustic22. Confidential Client Europe 30,000 Caustic23. Shell Oil Deer Park, Tex., USA 67,500 Caustic24. Lion Oil El Dorado, Ariz., USA 20,000 Caustic25. Valero Refining Company Paulsboro, N.J., USA 65,000 Caustic

*Total capacity of FCCU applications by EDV wet scrubbing: 1,212,000 BPSD (as of October 2002)


