Document KGVLJ0JbR6jmaj8DgQL60Nwx2

SATE HANDLING OF CHLORINE CONTAINING ''i * NITROGEN TRICHLORIDE Edition 1 Draft 8 Draft Statement: This document is in draft form for consideration by appropriate Chlorine Institute committees. It has not been approved for issue for any other purpose and does not at this stage reflect official Institute position. Should reproduction of any portion be required for appropriate use, copies should be clearly marked "Draft" or some equivalent. CHLORINE INSTITUTE PAMPHLET 152 The Chlorine Institute, Inc. 2001 L Street, N.W., Washington, D.C. 20036 DO 072892 OONF TDFNT T At SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 1 July IS, 1996 Edition 1 1. INTRODUCTION 1.1 Purpose This publication is intended to provide useful information to producers, distributors, repackagers, and users of chlorine concerning nitrogen trichloride to help prevent conditions from occurring that could lead to the explosive decomposition of nitrogen trichloride in chlorine containing systems. There has been a history of such destructive decompositions that has resulted in personnel deaths and injuries, equipment destruction, and chlorine releases. 1.2 Scope The following topics pertaining to nitrogen trichloride are discussed: hazard awareness physical and chemical properties sources and mechanisms of formation prevention of formation DRAFT DO 072893 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 3 July IS, 1996 Edition 1 Chemical Producers Association's (CCPA) Responsible Care initiatives. The Chlorine Institute is a Partner Association in the CMA Responsible Care initiative and is committed to the support of a continuing industry effort to ensure the responsible management of chemicals. 1.4 Disclaimer The information in this pamphlet is drawn from sources believed to be reliable. The Institute and its members, jointly and severally, make no guarantee, and assume no liability, in connection with any of this information. Moreover, it should not be assumed that every acceptable procedure is included, or that special circumstances may not warrant modified or additional procedures. The user should be aware that changing technology or regulations may require changes in the recommendations contained herein. Appropriate steps should be taken to ensure that the information is current when used. These recommendations should not be confused with federal, state, provincial, municipal, or insurance requirements, or with national safety codes. 1.5 Approval The Institute's Plant Operations and Safety Committee approved this pamphlet on 1.6 Revisions DRAFT DO 077894 CONFIDENTIAL SAFE HANDLING OF CHLORINE COISTTAININC NITROGEN TRICHLORIDE Pamphlet 152 Page 5 July IS, 1996 Edition 1 with as little as 1.5 gm/cm: liquid film of pure nitrogen trichloride. Further, 0.3 gm/cm' of surface area is capable of over-stressing the metal to the point of cracking or fissuration (9.4). Exposure of nitrogen trichloride to impact, light or ultrasonic irradiation may cause or sensitize detonation (9.5). Nitrogen trichloride is a powerful compound which has an explosive force that is approximately 30 to 40% of TNT. At higher concentrations (above 6-8%), nitrogen trichloride has catastrophic potential via detonation and it, therefore, must be handled properly and respected all of the time. In 9.3, numerous such incidents are documented. Nitrogen trichloride was first identified in 1811 from the action of chlorine on a solution of ammonium chloride by Dulong who lost an eye and three fingers as a result of an explosion. Dulong assigned the formula nitrogen trichloride to the yellow explosive oil. Other early workers prepared nitrogen trichloride in the same manner, accumulating only small quantities, but even so, several were injured by explosion. Following the discovery of the explosive yellow oil, early workers tested it with practically all of the chemicals and substances common to the laboratory at that time. The oil was found to explode violently when 1) heated to 95C; 2) exposed to strong light; or 3) brought into contact with substances such as ozone, phosphorous, arsenic, alkali and organic matter. DO 072895 CONFTDFNTTAL. SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 7 July IS, 1996 Edition l Table 2-1. Explosions Suspected to be Caused by Nitrogen Trichloride Incident Location Explosion of an empty chlorine rail car which had Belgium been unloaded via the gas phase Chlorine reboiler explosion; Major equipment damage Louisiana Compressor suction chiller drain piping explosion killing two people and one person's leg was severed above the knee Colombia Purification column pot exploded killing one West Virginia Cooling tower (believed to be compressor suction Michigan chlorine cooler) exploded killing one 2 Explosions in chlorine vaporizers have been reported, no details available Brazil One-ton container exploded Not Known One-ton container exploded Not Known Tank car cover blew off killing two Norway Three interconnected storage tanks (45 tons total Romania capacity) at a pulp mill exploded releasing 21 tons of chlorine Two one-ton containers exploded Not Known Date February 1995 March 1994 November 1993 March 19S3 November 1973 Not Known February 1949 November 1943 January 1940 December 1939 July 1923 3. PROPERTIES OF NITROGEN TRICHLORIDE 3.1 Select Physical Properties (9.61 Appearance Odor Molecular Weight Yellow Volatile Oil Pungent 120.38 DRAFT # 8 DO 072896 CONFTDFNTI Al safe handling of chlorine CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 9 July IS, 1996 Edition 1 Pressure Rise vs. Nitrogen Trichloride Concentration Vt * ^ ? i ,, Graph 3*2 shows pressure rise as a function .of concentration (Steve Fitzgerald to provide). DRAFT # 8 00 072897 CONFIDFNTTAl SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 11 July IS, 1996 Edition 1 3.2.1 Heat of Decomposition The heats involved in the decomposition reaction are as follows (9.2): NCI (soJutjo/j) -> 1/2 N, (J) * 3/2 CAJJ) A// = -54.7 kcaSmolc The chain initiation step is proposed as: NCJy ^ NCI, + Cl A// - *53.9 kcaHmole It is hypothesized that this step is followed by the following highly exothermic propagating steps: Cl * NCI) ^ NCI * Cl AH= -3.05 kcalmole NC1Z * NCI) ^ AC * 2 CL, * Cl A// = -106.2 kcalmole Even though the propagating steps are highly exothermic, a fair amount of energy is required to initiate the decomposition. This energy may be provided by heat, light, or a spark. Acetylene has nearly the same heat of decomposition and it also, when liquified, is sensitive to shock and may explode. Nitroglycerine (9.8) has a heat of formation of 88.8 kcal/mole but upon decomposition liberates about 367 kcal/mole or 1,615 cal/gram because of the partial combustion obtained from the oxygen contained by the DO 072898 CONFIDENT! Al SATE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 13 July 18, 1996 Edition 1 dynamite to ammonium nitrate/fuel oil in the salt mining operations may produce salt which contains higher concentrations of nitrogen compounds and leads to higher nitrogen trichloride in the chlorine (9.3). Similarly, sodium hydroxide used in brine pH control could be a source of ammonia contamination if the sodium hydroxide was purified 3 utilizing the ammonia salt removal process. 6 7 4.1.2 Other Sources of Contamination 8 9 Contaminants in brine or utility (e.g., steam, water) treatment chemicals in a chlor-alkali 10 plant can be a source of nitrogen trichloride formation. Urea is a particular concern as 11 it is hydrolyzed to ammonia. Possible urea contamination during a salt unloading 12 operation was the suspected cause of high nitrogen trichloride formation leading to a 13 1993 explosion which resulted in two fatalities (Table 2.1). 14 15 Sulfuric acid contaminated with ammonia used in the drying of chlorine has been shown 16 to cause an increase in nitrogen trichloride formation. Direct contact cooling water or 17 steam that is treated with amines, ammonia based flocculants. or chloramines, are IS another source of increased nitrogen trichloride formation. 19 20 4.1,3 Nitrogen Compounds that are not Converted to Nitrogen Trichloride 21 22 Not all nitrogen compounds are converted to nitrogen trichloride. For example, water 23 contaminated with caprolactam (hexahydro-2H-zepin-2-one) was inadvertently used to DRAFT # 8 DO 072899 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 1S2 Page 15 July 18, 1996 Edition 1 1 2 4 5 6 5. 7 S 9 10 11 12 13 14 15 5.1 16 17 5.1.1 IS 19 20 21 22 23 " \ 4i- Contaminants in brine or utility treatment chemicals or chlorine drying agents also will follow one of these mechanisms. PREVENTION AND DESTRUCTION The following discussion provides information that should be considered as a facility examines alternative methods for preventing nitrogen trichloride levels from exceeding safe levels. To the extent practicable, steps should be taken to prevent nitrogen trichloride from being formed. When prevention is not practicable, destruction techniques, coupled with appropriate control and monitoring (Section 8) techniques, should be employed to prevent levels from exceeding safe levels. Preventing the Formation of Nitrogen Trichloride Avoiding Sources of Ammonia Compounds in Brine Since nitrogen trichloride forms tn electrolytic cells from reaction of chlorine with ammonia compounds, the best method to prevent its formation is to keep these compounds away from the process in the first place. The following are general principles that should be considered: DRAFT # 8 DO 072900 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 17 July IS, 1996 Edition 1 t 5.1.2 Removing Ammonia Compounds from Brine 7 J 4 5 6 7 s 9 10 11 12 13 14 15 16 17 IS 19 20 5.2 l 22 23 Once the ammonia compounds are in the process, they can be removed by reacting with chlorine, either through direct chlorination or through addition of hypochlorite (bleach) (9.9). The target range for free chlorine concentration is 10 to 20 ppm. Volatile chloramine is formed, NH:CI, which can be stripped from the brine or water. This must be done under alkaline conditions, pH 10-12. Under acidic conditions, below pH 5, nitrogen trichloride, which is not volatile, is formed instead, so pH control is important. Typically, this method is used in brine systems after treatment for alkali metal removal. Another vessel may be needed to provide for sparging, and equipment must be protected from corrosion related to the sparging and the hypochlorite addition. NFL * NaOCl -* NFLCJ + NaOH [alkaline conditions, above pFF9.5) 2 NFf,0* NaOCl - N * NaCl * 1HCI * 1H,0 (conditions - Abraham to provide) NFL Cl * VzCL, - VzNj * 2FFQ (conditions - Abraham to provide) NFL + 30, -* NCI) * 3MCI {acidic conditions, belowpFL4.5) NH^Ci * Cl, -- NFL Cl * 2FLCI (alkaline conditions, above pFF9.5) Destruction of Nitrogen Trichloride Several ways have been found to destroy nitrogen .trichloride. Many of them give substantial elimination. DRAFT # 8 DO 072901 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 19 July IS, 1996 Edition 1 The most used catalyst for nitrogen trichloride destruction has been activated carbon. Destruction is complete. Problems such as channeling, bed fouling, and heat rise on startup have been reported, but these are often seen with catalyst bed systems, and are not specific to carbon. 5.2.2 Ultraviolet Light (9.11) Nitrogen trichloride will decompose when exposed to ultraviolet light. Several facilities use this technique successfully. The method is used on chlorine gas rather than liquid due to partial absorption of the light by chlorine. The required wavelength range is 3600-4780A. Usually, mercury vapor lamps are used due to their intensity and wavelength emissions. Other lamps emitting the correct wavelengths have been tested successfully in the laboratory. Typically, lamps are arranged in series for good coverage of the chlorine stream. Wall effects can be significant, and the chlorine gas itself will block the light. The design should consider the size and arrangement of the chlorine piping and layout of the lamps. The lamps have been used successfully both on wet and on dry chlorine systems. Each lamp will produce a reduction of 50 to 80% in the nitrogen trichloride concentration. Lamps are usually installed and operated in series down the length of a pipe or vessel to reach the required nitrogen trichloride removal. Since ultraviolet light will trigger reaction of hydrogen and chlorine, operating procedures should address this additional reaction. 8 DO 07290? CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 21 July 18, 1996 Edition 1 into the suction chiller. The liquid that accumulates at the bottom of this vessel dissolves the nitrogen trichloride and is high in nitrogen trichloride concentration. The liquid is often drawn off into a tower of refluxing solvent, e.g., carbon tetrachloride. The reboiler of the tower operates at a temperature above the decomposition point for nitrogen trichloride so that the nitrogen trichloride is continuously destroyed. Historically, this type of system has had several nitrogen trichloride explosions. The design must be carefully reviewed to be sure it provides adequate controls to maintain nitrogen trichloride destruction and prevent nitrogen trichloride accumulation. 5.2.4 Acidification Wet chlorine gas can be treated with aqueous hydrochloric acid, which will decompose the nitrogen trichloride and remove some water and other impurities (9.12). This method is typically used at acid concentrations between 23 and 30%, and at a temperature of about 10C. A dilute acid stream is produced that is high in ammonia content. This can be treated to remove the ammonia, making the acid suitable for use in brine pH adjustment. Concentrated sulfuric acid and iron can be used together to decompose nitrogen trichloride but a milky precipitate is formed that fouls equipment. 5.2.5 Reducing Agents DO 072903 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 23 July IS, 1996 Edition 1 1 2 J 4 Jc 6 7 3 9 10 11 12 13 14 15 6. 16 17 6.1 IS 19 20 21 22 23 The nitrogen trichloride will be an oily, yellowish-green liquid, with an odor similar to chlorine. Secondary explosions have occurred from nitrogen trichloride on the ground after an initial nitrogen trichloride explosion. The area of a spill after a nitrogen trichloride explosion should be treated to destroy any nitrogen trichloride. Of the destruction methods described above, the reducing agents are the best choice for decontaminating an area of nitrogen trichloride. They are readily available, and have relatively less environmental impact than the other options. They should be applied cautiously in a dilute form, (approximately 5%) sprayed in a mist over the affected area. After application, sumps and low spots should be inspected to insure there are no remaining puddles of nitrogen trichloride. The area should then be washed down thoroughly with water. LIMITING LEVELS OF NITROGEN TRICHLORIDE Basic Principles The concentration of nitrogen trichloride in a chlorine system must be limited because nitrogen trichloride can decompose exothermically. Although the decomposition occurs at all concentrations of nitrogen trichloride, the decomposition rates accelerate to catastrophic proportions when the nitrogen trichloride concentration reaches 6-S% nitrogen trichloride (9.3). In concentrated form, the liquid behaves as a sensitive DRAFT # 8 DO 072904 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 25 July 18, 1996 Edition 1 avoid reaching a level of 6% of nitrogen trichloride, the nitrogen trichloride concentration should be limited to 2.0% (20,000 ppm) in all parts of the installation where nitrogen trichloride could concentrate during both normal chlorine and solvent operations and shutdowns. 6.3 Maximum Levels or Nitrogen Trichloride in Chlorine Introduced into Containers The nitrogen trichloride concentration should be limited to 2.0% (20,000 ppm) in all parts of the installation where nitrogen trichloride could concentrate during both normal chlorine and solvent operations and shutdowns. The allowed nitrogen trichloride levels have been established taking into account the potential concentration of nitrogen trichloride, particularly where there is intended or unintended vaporization of the chlorine in the gas phase. The calculations carried out for a specific installation should take into account: the quantity of nitrogen trichloride which might be present after complete vaporization of the chlorine * the capacity and the geometry of the container DO 072905 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 27 July IS, 1996 Edition 1 maximum level. These steps should be taken before the final concentrations are removed or the chlorine is evaporated. 4 6.4.2 Chlorine Cylinders and Containers 5 6 Chlorine cylinders and containers of up to one ton are frequently used for extraction of 7 chlorine gas rather than liquid. Their size, however, is such that dangerous quantities of 8 nitrogen trichloride-rich material will not accumulate at the later stages of emptying if a 9 limit of__ppm w/w nitrogen trichloride is set for chlorine put into small containers. 10 Adequate cleaning procedures must be in practice at the packager to assure no build up 11 of nitrogen trichloride after several cycles, n 13 6.4.3 Bulk Transport Containers (Tank Cars, Tank Trucks, Barges) 14 15 Almost all road tankers of liquid chlorine deliver directly to customer storage and it is 16 only in well-defined circumstances that gas is supplied to a point of use. Most rail tanks 17 are also used in prescribed deliveries to customer storage where the mode of operation 18 is guaranteed to be the direct discharge of liquid. The nitrogen trichloride limits, 19 therefore, are set by the use to which the chlorine will be put or by the behavior of the 20 residual chlorine left in the vehicle until refilled. The recommended limit for nitrogen 21 trichloride in these circumstances is__ppm. A higher limit can be tolerated for smaller ?? containers or for chlorine known to contain significant amounts of components of higher DRAFT# 8 Do 072906 confidential SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 1S2 Page 29 -* July 18, 1996 Edition 1 Whenever the chlorine manufacturing process or source of raw materials are changed (e.g., water, salt, brine, brine chemicals, drying acid), a check should be made to ensure that a new nitrogen trichloride source has not been introduced. 7.1 Process Parameters The ammonia compounds in raw brine, cell feed brine and other additives introduced in the process (e.g., H:SO,, HC1) and nitrogen trichloride in liquid chlorine product should be measured to determine base line levels for the process. Any modification to the materials used in the process should always be accompanied by a check against any potential problems connected with nitrogen trichloride. The parameters that can affect the concentration of nitrogen trichloride (e.g., ammonia compounds in the various streams and process conditions such as temperature and flow rate) should be identified and monitored. Statistical Process Control (SPC) or some equivalent method can be used to decide the frequency of monitoring. If parameters that can affect the concentration of nitrogen trichloride are increasing, the frequency should be increased. Nitrogen trichloride accumulation points (e.g., reboiler, chlorine condensers using liquid chlorine, purge line from vaporizers) should be identified and a monitoring frequency based on variability and nitrogen trichloride concentration should be established. 8 DO 072907 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 31 July 18, 1996 Edition 1 Safe design and operation of a process (i.e., purification column, compressor precooler or intercooler, or suction chiller) where gaseous chlorine is chilled by direct contact with liquid chlorine resulting in the condensation of the higher boiling nitrogen trichloride must be predicated on moving any collected nitrogen trichloride to a place where conditions are such that it is diluted and removed or decomposed to a safe nitrogen trichloride concentration. Special attention must be given to ensure that free flow of gas and liquid exists within the column, i.e., use of pressure drop indication. A plant shutdown or other appropriate procedures should be mandated if flow restriction in the column becomes evident. The liquid chlorine feed to the column should be controlled such that the feed rate is not cyclical and is sufficient to prevent a dry tray or packing condition where nitrogen trichloride would concentrate to dangerous levels. If an organic solvent is used, its selection for use as a diluent should consider the reactivity with nitrogen trichloride and chlorine, relative boiling points, solvent stability, and solubility characteristics. The reboiler design should consider corrosion potentials and heating designs that minimize the possible intrusion of water vapor. In batch removal systems, special precautions must be used to establish the removal frequency of the nitrogen trichloride containing stream and have operating procedures to ensure the discharge line is not plugged, and to limit the heat transfer and temperature during the chlorine de gassing step. Other situations where nitrogen trichloride can accumulate are vacuum sniffing to recover returned liquid chlorine heels in rail cars, barges, or other containers, vapor unloading of liquid chlorine from a shipping container, chlorine vaporizer operation, chlorine DRAFT DO 07?908 CONFTDENTIAI SAFE HANDLING OF CHLORINE CONTAJNING NITROGEN TRICHLORIDE Pamphlet 152 Page 33 July IS, 1996 Edition 1 control (SPC)] should be encouraged for the critical process parameters from ammonia in brine to nitrogen trichloride in the final chlorine product. * The design of chlorine processing or use systems including any nitrogen trichloride destruction system should consider the use of simulation calculations as a tool to aid the process hazard review (PHR) in defining the potential'situations for the development of high concentrations of nitrogen trichloride. Raw materials and operating chemicals should be monitored for ammonia-containing compounds especially during the process of changing suppliers or sources of the materials. As discussed in Section 5.2.3, Reference 9.3 (Ross and Bowling) indicates that at a 95C compressor discharge temperature, nitrogen trichloride will be reduced by more than 90% as the chlorine gas passes through the compressor. However, this destruction efficiency is both temperature and residence time dependent. Other information indicates the destruction efficiency can be less than 50% in some (centrifugal compressor) installations. Each site needs to verify the destruction efficiency for its unique system, especially if this system is the primary removal system for nitrogen trichloride. 1 For Users/Repackagers 072909 CONFIDENTIAL SAFE HANDLING OF CHLORINE CONTAINING NITROGEN TRICHLORIDE Pamphlet 152 Page 35 July IS, 1996 Edition 1 1 9.6 2 3 4 9.7 5 6 9.8 7 8 9.9 9 10 9.10 11 12 9.11 13 14 9.12 15 16 9.13 17 18 9.14 19 20 9.15 21 22 Mellor's Comprehensive Treatise on Inorgance and Theoretical Chemistry-, EDITOR; PUBLISHER: CITY, YEAR; Vol. 8, pp 583-605. Noyes, W.A.; Tuley, W.F. Jacs. 1925, 47, 1336. Taylor, J. et al\ J. PhysL and Coll. Chem. 1947, 51. NAME. U.S. Patent 3 597 156, 1971. NAME. U.S. Patent 2 692 818, 1954. NAME. U.S. Patent 2 705 219, 1954. NAME. U.S. Patent 3 568 409, 1971. NAME. U.S. Patent 4 13S 296, 1979. NAME. U.S. Patent 4 230 673, 1980. Maximum Levels of Nitrogen Trichloride in Liquid Chlorine, ed. 9; Euro Chlor: Brussels, 1990. DRAFT # 8 DO 077910 CONFIDENTIAL k\w * i l Jw BPPbwpi)' \ 1 9- Static Boil-Down of Liquid Chlorine Containing 1, 5 and 15 ppm NCb Data is representative for any volume of CI2 at the respective temperatures, starting with a 15% freeboard vapor space; c.g., from storage tanks, to cars to cylinders. / Temperature - -3Q`F Pressure = 14.7 PSIA Temperature = 0* F Pressure = 2S.6 PSIA Wr.So Full 100 50 25 10 5 2.5 1.0 0.50 0.25 0.10 0.01 ppm NCb in Liquid Heel (Initial) 1 1 2 a 9 ____ 18 84 163 312 715 -3,637 ppra NCb in Vapor 0.0 0.0 0.1 0.1 0.3 1 3 6 11 25 128 ppm NCb in Wt.Sr Full * Liquid Heel 100 50 25 10 5' 2.5 1.0 0.50 0.25 0.10 0.01 (Initial) 1 1 2 4 9 18 85 165 317 703 2.970 ppm NCb in Vapor 0.0 00 01 0.3 1 _3 ... 5 10 21 90 Temperature = -30*F Pressure = 14.7 PSIA Temperature = 0* F Pressure = 28.6 PSIA Temperature =30' F Pressure = 51.1 PSLA ppm NCb in Wt.* Full . Liquid Heel 100 (Initial) 5 50 7 25 10 10 19 5 46 2.5 90 1.0 421 0.50 813 0.25 1.558 0.10 3,701 . 0.01 17,955 ppm NCb in Vapor 0.2 0.2 0.3 0.7 1.6 3 15 23 55 125 642 * ppm NCb in Wl%FuU Liquid Heel 100 (Initial) 5 50 7 25 10 5 2.5 1.0 0.50 0.25 0.10 0.01 10 20 47 91 428 822 1.570 3.506 14.820 ppm NCb in Vapor 0.2 0.2 0.3 0.6 1.4 3 13 25 46 107 4S4 * Wl'S. Full 100 50 25 10 5 2.5 1.0 0.50 0.25 0.10 0.01 ppm NCb in ppm NCb Liquid Heel in Vapor (Initial) 5 7 0.2 0 10 0 19 0.5 47 1 91 3 429 12 824 1.544 3.327 23 44 -94 11,290 - 321 Temperature = -30*F Pressure = 14.7 PSIA Temperature = 0* F Pressure = 28.6 PSIA ppm NCb in ppm NCb Wi% Full Liquid H1 in Vapor it ppm NCb in ppm NCb Wt.56 Full Liquid Heel in Vapor 100 50 (Initial) 15 20 1 1 100 (Initial) IS 50 20 0.5 0.6 25 29 1 25 29 0.9 10 57 2 10 57 1.8 % 5 138 5 2.5 269 10 5 140 4.3 2.5 273 8 1.0 1,262 44 1.0 1.287 39 0.50 2.438 86 0.50 2.475 75 0.25 4,660 165 0.25 4.665 144 0.10 10,608 ' X7S 0.10 10.443 321 0.01 52.170 1.931 0.01 42,94b 1.364 * Wi. % Liquid CJ2 Full (exclude! vapor .(.) Wl of Liquid 02 Heel LmiiaJ (loUi) Wt. of Liquid C12 x 100 DO 072911 CONFIDENTIAL