Document ZnY5qMZBy2RV3ML4RX0aZ1170

560 Dewalt Drive Pittsburgh 3*v, Pa May 6th, 1953 Dr. T.A.Boyd Research Laboratories Division General Motors Corporation Detroit 2, Michigan Dear Dr. Boyd: Pollowing your very instructive and entertaining talk at the Pittsburgh Chemists Club last night, I vould like to have talked to you about the recovery of lead bromide from the spent TEL in automotive fuel consumed. I believe my thoughts to be provocative but can see no practical way to achieve a profitable recovery. The automobiles themselves, together with the winds that blow have done such a job of distribution that the prospects for recovery would seem akin to G.H.Lewis' probability of unscrambling an egg by scrambling it long enough. We know that lead is,and will be the more so, in short supply. We also know the large amount of lead required to supply the national demand for TEL and the considerable amount of bromine required for ethyl fluid. The thought occurs as to whether there are any sources where recovery of lead and bromine might be considered. Two sources which have intrigued am are as follows: (lX- Street sweepings in populous cities. Power sweeping is practiced in large cities and the refuse is presumably used for land-fill. The concentration of level bromide Is. certain to be very small, perhaps too small to warrant any work of extraction by leveling with hot water or by sublimation by heating. Classification processes involving air or w&te/ flotations might enter into a scheme of. separation. The organic matter in sweepings although probably not near as high as it was in the horse and buggy days, presents a problem in any recovery scheme. It might well be that the recovery process would become one of producing a soluble insecticide for garden plants from extracting the cigars and cigarette butts. Bromine can, of.course, be freed from lead bromide using sul furic acid and several schemes are available for the recovery of lead as : such. `' H v (3) Exhaust gases from vehicular tunnels. Presumably electrostatic pre cipitation would give a concentrate of lead bromide which could be > worked into lead and bromine as already indicated. I had thought this source would yield sizable amount of these elements but my calculations concerning the Holland Tunnel proved disappointing end disuaded me from any thought of going into the business. Here they are: N15316 -2- In 194o, 13,331,159 chicles uded the tubes Tunnel Is 1.6 miles long. Assume lOOjt recovery of fuses. 18 miles per gallon gasoline. 2 ml. ethyl fluid per gal. 60J& volume TEL, bCfjt ethylene bromide. \ TEL sp.g. 2.0mol. wt. 323.5 it Br2 sp.g. 2.18 aol.vt. 188. x 1.6 1.170.000 gal. gasoline x 2 2.330.000 ml. ethyl fluid x .6 1.400.000 TEL X 2.00 2.800.000 gmis. TEL x jg.08--. 1.800.000 gms. Fb. > k&r*** %,Q0 lbs.Fb. 2.330.000 930,000 2,l8o,6QO 1.860.000 4,000 ml. ethyl fluid x .4 ml. it Brg x 2.18 gma.3Et.Br2 x l6fl gas. Br2 > lbs. *2S?.0w*^ _ & On .this basis, tvo tons of lead and two tons of bromine might be recovered per year, which is hardly a sizeable amount. .. It has been estimated that the usage of lead for anti-knoeh is 10$ of the total lead usage i. It is about l-l/VmillioR tons per yeax. If evenly dis tributed over the area of the coatiaentai J&ited StatesV. it would amount to apprORiaately l/2 ton per q.uarjgile or l lbB. ]?ar acre. While ' ' there will be much higher! depositions ia pc^ulouft areas (one can arrive at; y a figure of 5-t6as per s^xiare wdLle for tha District of Columbia), I doubt1. 4; . I vi . ............................. .. . ............................ ............ ... ............... ........................ ,.v.. , ......v,.? ......... / .................. . ... . n * ,,'/**' f ir % ^ ' * V * 1 \ f% ' *1 ,K<f 00 VA 1 ,,i V^ `" . *??(\ ' \ ' Si *' it these! figures can h obtained with any accuracy because of the diet: effect of winds. . The fuses from American automobile exhausts, I belie since penetrated in some degree, the Jungles and deserts of all contin* and both polar regions.^ . Much of the lead salt fumes is no doubfcvaal into the streams by rains, and, as with all mineral matter possessing 4 degree of solubility, the lead salts must eventually concentrate in th< Of course, one might postulate each motorist recovering his bit of leac \ salts by some collecting device attached to the exhaust system and a collection system to round up the whole tonnage. This la hardly prac ticable for a number of reasons. I thank you for having the patience to hear me out in this matter, (ass you have read this) and X would be interested in khovijog what you,and any others with much experience in this field, think. ms/S