Document 1goqzEmxLV8N4oQyoM28q1vYd

INTER-OFFICE CORRESPONDENCE Et h y l Ga s o l in e Co r p o r a t io n Ma n u f a c t u r in g a n d t r a f f ic De p a r t me n t MAIL ADDRESS: BOX 1271. WILMINGTON, DEL. FREIGHT ADDRESS: CARNEY*9 POINT. N. J. TELEPHONE: PENNSGROVE. N. J. 280 EXTENSION 890 May 11, 1938 Mr. J. H. Schaefer Bear John: Ne are attaching letter of April 28 from Oscar Lewis to yourself relative to the steaming experiment of Mr. Ball. Our analytical results on the samples forwarded by Ball are as follows: -- Sample I'iO Color Total Lead Calculated as T.2.L. (cc. per gallon) / TotaJL Lead Calculated as $ PbV 3T-1 {HpO portion) ST-1 {Solid portion) ST-2 115$ ST-3 140 ST-4 160 ST-5 175 ST-6 ST-7 220 3T-8 290 ST-9 350 ST-10 ST-11 350 ST-12 (HgO portion) ST-12 (Resinous portion) ST-13 (H20 portion) ST-13 {Solid portion) 2.79 3.22 3.51 17> 3.85T 3'. 53".\ 3.9l\ 3.84 4.25 3.91 X 'X} ) s Thaee only. Less thanv00005$ v USXBb Found) x. 0.107$ 0.121 0.129 0.118 0.132 0.124 0.139 0.24 0.145 0.12S 0.016 0.066 Non 0.0043 Total Lead /^Calculated Sre-1^TTS:X,T~ X 0.025$ 0.104 Non 0.0067 Samples ST-1 and ST-13 each consisted of a solid portion containing iron scale and a gritty or sandy substance and a water layer above the solid matter. The water was separated from the solid by filtration and each portion tested for lead. Sample ST-12 contained a resinous or gummy layer with a water layer above. These were also separated and each tested for lead. -2Lrr. J. H. Schaefer May 11, 1938 In cessmenting on the analytical results, it is our opinion that Sample ST-9 shows probably too high a figure for lead content but that all other results are within reason. Not much value can be placed in the color strengths since here we run Into increases in color due to concentration during steaming and also show color deterioration due to prolonged applica tion of heat. Otherwise, we leal that all analytical figures are selfexplanatory. The report of experimental procedure and the analytical results hare been discussed with both Colvin and Biehle and we are including the con sensus of our opinions in commenting on this subject. First, the quantity of five gallons of gasoline in a 5S-gallon drum seems quite proper sinoe this corresponds to three square feet of refluxing surface per gallon, very nearly the same surface per gallon as found in a standard SO* x 40* (20,000 barrel) refinery tank when there are two inches of gasoline in the bottom. The fivegallon gasoline content also corresponds fairly closely with two inohes in a 20,000-barrel tank on the basis of area exposed. For example, in the tank, there were 0.77 square feet of gasoline exposed per gallon, vhereas in a 20,000-barrel tank, a 2-inch depth corresponds to an 0.82 square-foot exposure per gallon. However, two items in the report indicate that the quantity of steam Introduced was entirely too great for parallel comparison*. The temperature of 140 was reached in between two and three hours, whereas at the refinery, twenty-four to thirty-six hours are required before reaching that temperature, the theoretical goal. In this test the'maximum ran up to 170 for over one hundred hours. These temperatures are Fahrenheit, Furthermore, the steam condensate amounted to one gallon per hour or in total, tv&ca the content of the experimental tank. To have been consistent with refinery experience, total condensate should not have exceeded ten gallons, basing the quantities on comparable units of refluxing surface. The one experience in the test which seems out of line with refinery experience is why it took longer to strip out the gasoline than is normal for a tank steaming vihen using steam quantities so much greater than normal. The explanation may be due to the strong draft or chimney effect ventiJag refinery tanks, which, effect ie virtually non-existent in a small container. The statement is made in the report that lead in draw-off water is probably negligible due to the very slight solubility. This does not necessarily follow since lead might be present in suspended or emulsified form in sufficient quantities to affect results, particularly considering the larger than normal ratio of draw-off water to gasoline. KE 00225S0 -3Mr. J. E. Schaefer Uay 11, 1938 If the reflux ratio in the tank has any relation to the removal of lead by steaming, then the small scale experiment is not comparable to large tank steaming. The ratio of unwetted drum area to free drum volume is almost twenty-five times the same ratio for a 60* x 40* tank. The effect upon refluxing la shown by the fact that in the field the condensate amounts to about three times the volume of the gasoline, vhile in the small scale experiment, even in the first forty hours, the ratio of condensate to original gasoline was 8tl. i.s has been borne out by the analytical results, it is reasonable to suppose that the concentration of lead in the residual gasoline increases as the steaming progresses. Therefore, considerable lead will be distilled in the' latter stages of the steaming. In the experiment, the latter stage might be considered the period from forty hours on, when the last 10$ of gasoline '.fas distilled. During the last sixty-five hours, approximately sixtyfive gallons of condensed stecm refluxed into the tank and must have carried quite a bit of the lead vith it. The layer of gasoline during the period was not over one-quarter inch in thickness and therefore, re-absorption of lead by the gasoline must have been lower than at first. From these considerations it would not be surprising if a large amount of suspended tetraethyl lead left the drum with the sixty-five gallons of draw-off water. Finally, in order to interpret the results more intelligently, it would bo preferable to retain a material balance during the course of the experiment. In this way it might have been possible to check the results. There are several factors to be considered in interpreting the results. First, let us assume that the sample of sludge submitted was represent ative. *e estimate the total sand used up to a three-inch level to be equal to 0.4 cubic feet, with an estimated weight of forty-eight pounds at 120 pounds per cubic foot. The lead present in this weight of sludge, as tetraethyl lead, is 1.5 grams based on the 0.006?$ of tetraethyl lead for the solid portion of ST-13 and calculated from the assumptions just made. The resinous portion, which analyzed at 0.104$ tetraethyl lead, shows a total residue of 0.2 grams a3 tetraethyl lead based on the 1$ of original volume as the residue, and the same gravity as for water. The total residue of tetraethyl lead found in the container la therefore equal to somewhat loss than 10$ of the original weight of tfeenty-three grams of tetraethyl lead present. Thus, it is safe to assume that in the steaming operation at a refinery, at least 10$ of the quantity of tetraethyl lead present in the gaso line layer will remain after completion of the steaming and that in all probability the lead residue will exceed this figure. I'-'e are attaching several extra copies of this report for your con venience in the event that you find it advisable to distribute it In its present form. Youra very truly, H 0022581 A, ?. Stover Bo3ton, Masa STEAM TEST I. General In. preparing gasoline storage tanks for cleaning, the quickest method in driving out vapors and the remaining gasoline is to steam the tank for at least forty eight hours. The question has arisen as to what happens when leaded gasoline tanks are steamed. A tent on a small scale was carried out to bring to light some preliminary data on this subject. II. Purpose A. To determine whether or not lead is driven Into the remaining gasoline a3 successive fractions are 3teamed off in a leaded gasoline tank. B. To determine whether lead is driven into sludge during this process. III. Description of test A. Equipment used - 1 - 55 --"allon drum 1 - 30o - UoOOF thermometer Steam connections at 150 lbs. per square inch pressure Iron rust and scale used as "sludge" A 15" x 1" rusty iron pipe partially submerged in gasoline and water corresponding to a position of a swing arm. Water draw off bottles Sample collecting bottles B. Preparation. The drum (hereafter referred to as tank) was placed in a hori zontal position with a 2" hole in the top, and a 5" hole cut in the side 6" from the bottom of the tank. At the other end of the tank an 8" removable cover was held in place by stud bolts to assist In sludge removal at the conclusion of the test. A steam jot from a " line was connected at the 5" hole at the end of the tank, and a steam line was placed in the top man hole. These wors controlled by separate valves. A jM water draw off was placed 3" from the bot tom of the tank on the same end of the 2" hole. Iron rust, scalo, sand and water were then placed in the tank until the water level reached the height of the draw-off. A "sludge" sample was then taken. It should be explained here, that this test was carried out on a small scale for two reasons. We had no appropriation to work with so therefore could provide no elaborate get u p such as a large tank, scales, etc. Secondly, we felt closer control could be kept over a 3mall operation such as this one. N22585.01 -2- 4 On this basis, we used five gallons of Ethyl gasoline in this tank. As we desired to take a sample as each 10$ was driven off, we first calibrated the 10$ points on a measuring rod with water. The gasoline was then olaced in the tank, and the readings checked for a full 100$. The thickness of the level of the gasoline layer on the top of the water was about 2| inches, and brought the level of the en tire contents of the tank I" below the opening in the end where the steam was introduced. In discussing tank'cleaning with various plant opera tors, we have found that the layer of gasoline on top of water will sometimes run between 1 and 3 inches. We :o not maintain that 2 inches is an average, but wa still feel it is within limits of actual practice. According to the A.P.I. figures, tank steaming is normally run be tween the temperature3 lUo and 170 F. This represents from 20'$ - 4o$ steam saturation. This saturation is reported to be satisfactory to make combustible mixtures safe. In keeping with general practice, the temperatures throughout tbi^ test were run between these limits. The steam was turned on thru the top man hole, and gradually worked \tp to 135cF. We introduced ste .m thru the top in order to effect a smother ing action on the vapors in the tank. This is common practice at the beginning of steaming a tank, and this procedure was followed until about 30$ was steamed off. As the tank wan steamed., water formed by the condensation raised the level of the water bottom so as to throw off any readings we might got by sticking the tank. It was necessary therefore to draw off any ac cumulated water thru the tap provided for this purpose. 3y drawing the water to this level, we reached the zero point on our calibration or measuring rod, and readily determined how much gasoline had. been steamed off. The lead solubility in water being extremely low, we believed any water insoluble products would go directly to the bottom of the tank. Inasmuch a3 we were primarily trying to determine whether or not the l^a3 content of the residual gasoline wa;; increasing, we felt that drawing off water would have little or no effect on the soluble lead in the gasoline. Sampling was carried out thru the same draw off. This name m-thcd of determining the fractions steamed off and sampling was followed throughout the test. We tried to sample at each 10$ point, but this was found to be impossible. The* following schedule gives sample identification (St. for 3team test) along with temperatures at the time sampling was taking place. Samele No. Temperature Identificatlon St. 1 -- Sludge before test St. 2 --- Cities Serv. Ethyl before test ! St. 3 135 After first 10$ steamed off St. 4 117 25$ St. 5 St. 6 130 30$ l4o 40$ St. 7 St. S 142 50$ l4o 60$ KG 0022583 :\--T -J- inrole No. st. 9 St. 10 St. 11 St. 12 st. 13 Temperature ' 1600 170 170 170 -- Identification 80$ 90$ 95$ Residue on water bottom Sludge after test The temperature ms lowered to approximately 120F after the first 10$ was taken off, as It was felt the teat was running too ranldly. Oven though wo did lower the temperature the next 10% point was not hit, and we had to take a sample after 25$ of the gasoline had "been steamed off. We also took a sample at the 30'4 point. From then on, we hit the 10> points fairly regulatly, excepting the 70a1 point which came off during the night. Steaming was not continuous until after the 50$ point had bean reached, as the fractions were coming at too frequent intervals to allow running over night, here, a question may "be raised as to whether some variable might have been introduced by shutting down from time to time, instead of running a continuous test. We know that when the steam is shut down, the reaction slows down due to lower temperatures, and also that more water is condensed into the bottom of the tank. Aside from this, we cannot see where shutting down would interfere with the purpose of the test. Incidentally, both man holes were closed when the test was shut down. The following gives a brief log of the test. Accumulated Steaming Time Tine Occurrence 0 15 minutes 45 1 hr 45 2 " 30 " 2 " 30 " 3 hr 30 minutes g 45 9 30 " 9 " 30 " l6 hr. 30 minutes 34 hr. 15 4o 11 30 " 57 " 30 " 105 hrs. flat Tues. Mar. ?$, 2:00 PM 2:15 PM 2:45 pm 4:00 PM 4:45 p m led. Mar. 30, 10:00 AM 11:00 AM 4:15 PM 4:45 p Thurs.Mar. 31 Thurs.Mar. 31 4;45 pu Fri. Apr. 1 10:30 AM 4:4p p m Sat. April 2, 11:00 AM Mon. April 4, 11:00 AM Test started First 10$ off First. 25$ off First 30$ off Steam off Steam on (Rag plugging man hold saturated with gasoline) First 404 off First 50$ off Steam off Steam on (continuous steaming) First 60i off First 80/?- off First 90$ off First 5$ off Steam off A3 can be noted from this log, although the tank was-steamed for 105 hrs, over 95$ of the gasoline was removed in 59 hours or approxi mately one half this time. The residue was a viscous substance - about the consistency cf petroleum jelly. It is estimated this residue, remaining after 105 hours steaming, represented about 1$ of the total volume of gasoline put in the tank. KE 0022584 _h~ IV Commenta Inasmuch a3 the a team test as carried on in a 55 gallon drum, it is "believed this could be used as a "basic unit in determining larger testa. For example, it was foun; that approximately one gallon of water condensed every hour at 20'?* steam saturation* If a test should ho safe on a larger tank - by knowing the sire of this tank - the condensation of water could be determined by mltiolying the size ir barrels by one gallon per hour. It is believed any tank should be steamed at least fort;* eight hours to free the tank of vapors, if steaming alone is to be depended upon. H Ball K'E' 0022585