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WILLIAM S. HILL. Member, Examining Corps, United States Patent Ofice. DIRECT SYNTHESIS OF HYDROGEN PEROXIDE. A well-known laboratory process ...
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WILLIAM S . HILL Member, Examining Corps, United States Patent Ofice DIRECT SYNTHESIS OF HYDROGEN PEROXIDE

A well-known laboratory process which has also been used commercially for the production of hydrogen peroxide involves the reaction between an acid and barium peroxide. There is also an electrolytic method in which hydrogen peroxide forms a t the anode of an electrolytic cell. In order to combine hydrogen and oxygen directly to form the peroxide various expedients have been tried with more or less success. The use of a silent electric discharge, an intensely heated wire, and ultraviolet light are some of these. The process described in this patent depends on the use of catalytic surfaces which greatly speed up the thermal reaction between hydrogen and oxygen to produce the peroxide. Reaction tubes having smooth dense surfaces were found to be best. Glazed porcelain and fused silica preferably with a coating of fused boric acid or a metal borate greatly increased the yield of peroxide. The reaction tubes are heated to a temperature of around 520°C., and a mixture of hydrogen and air is passed through. The mechanism of the reaction is thought to be: H

+ O2 + H a

M + HO1

+ M + 52 kilocalories (or more)

+ HZ+HlO9 + H - 18 kilocalories

M is any third molecule in the gas phase, or the surface of the reaction vessel. No. 2,368,640. Gerhard A. Cook, Snyder, New York, assignor to Carbide and Carbon Chemicals Corp., Cambridge, Massachusetts. DEFLUORINATING ROCK PHOSPHATE

Rock phosphate intended for use as a fertilizer must first have its fluorine content removed. This is usually done by treating the fused phosphate with water vapor. An analysis of rock phosphate invariably shows an excess of CaO over that equivalent to tricalcium orthophosphate (3Ca0,PzOa) based on the Pz05 content. In order to increase the fluidity of the melt when the rock is fused for the removal of fluorine, an amount of SiOz is added above that already present in the rock. Other acidic oxides are also added, for example, FeO and AlzOa Enough SiOzis added so that there will be 2 mols of SiOl present per mol of excess CaO and enough of the other acidic oxide material is added to furnish an additional mol of acidic oxide per mol of CaO. Using the above method the rock phosphate can be melted a t 1500°C., which is much lower than the

fusing point of the natural material. The rate of defluorination is also increased so that i t becomes twobr three times as rapid. No. 2,368,649. Kelly L. Elmore, Sheffield, Alabama, assignor to the Tennessee Valley Authority. DESALTING OF MINERAL OIL

Crude oil usually contains varying amounts of salt depending upon the field from which i t is obtained and even the season of the year. This salt usually varies from 15 or 20 g. to 100 g. per barrel of crude and is objectionable since it fouls and corrodes the distilling and catalytic cracking equipment. Wax is also an undesirable impurity found in crude oil and must be removed along with the salt. The wax may be removed by settling a t a low temperature. The wax crystallizes and as it settles out takes most of the salt along with it. If the oil contains only small amounts of wax, additional wax may be added in order to remove the salt more completely. In order to obtain the lower temperatures favorable for crystallization of the wax the salty crude is pumped into a low-pressure chamber. This "flashes" the volatile constituents and reduces the temperature. Wax and salt may be separated by heating the mixture. This melts the wax, which floats to the top, salt being drawn off in solution a t the bottom. No. 2,366,792. Chalmer Kirkbride, Texas City, Texas, assignor to Pan American Refining Corp. USE OF COAL AS ION-EXCHANGE MATERIAL I N WATER PURIPICATION

New ion-exchange materials have been developed out of a number of substances including synthetic resins. They are in widespread commercial use in purifying water, since they remove undesirable soluble impurities almost as completely as distillation methods. In this process bituminous or semi-bituminous coal is treated with a sulfating agent such as fuming sulfuric acid. The coal is first preferably granulated to about 30 to 50 mesh. The temperature of reaction is maiutained a t 75 to 100°C. About 4 lb. of fuming sulfuric acid are needed per pound of coal. The acid is added slowly and reaction continues for two to three hours. At the end of this time excess concentrated acid is removed and the treated coal is thoroughly washed with water. After drying it may be left in the form of a hydrogen-exchanging zeolite or treated with sodium carbonate to change i t to a sodiumexchanging zeolite. Although bituminous coal is said to make the best

product, any kind of coal including anthracite or lignite may be used. No. 2,371,427. John G. Dean, et al., assignors to The Permutit Co.

ane, or ethylene. The apparatus about to be described is useful in completely separating out the carbon dioxide.

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NEW ADDITION AGENTS I N ELECTROLYTIC TIN DEPOSITION BATHS

When our supply of tin from the Malay States was suddenly cut off by the Jap offensive the outlook for tin-plated sheet iron looked very dark indeed. And since Amerisa had become used to living out of cans the sudden cutting off of our tin supply was a big blow to our economy. Since it was considered less expensive, tin plating had been done mostly from molten baths of the metal. Then it was found that satisfactory tin plating could be done electrolytically using a much reduced thickness of tin. The saving in tin which this permitted probably saved the tin-plate industry. Difficult problems had to be solved, however, before the electrodepositing of tin became commercially practical. At first the tin deposited as long needles perpendicular to the base, leaving spaces of the base metal uncoated. A lot of experimenting was required before satisfactory addition agents were found which improved the quality of the tin coatings. The present invention is for a new composition of coating bath involving new addition agents. In general, the bath contains a stannous salt to supply the tin, either sulfuric acid or hydrofluoric acid, a sulfonated compound such as sulfonated o-cyclo-hexylphenol, and nicotine. The nicotine is used in place of the proteintype colloids formerly used and is said to offer advantages such as freedom from gummy precipitates and sludge. The new addition agents are said to be useful in the deposition of other metals among which are zinc and lead. No. 2,370,986. John S. Nachtman, Pittsburgh, Pennsylvania. SYSTEM FOR GAS ANALYSIS

One method of prospecting the earth's surface for oil deposits involves analysis of soil gas mixtures for hydrocarbons indicative of oil deposits underlying the points of the earth where the mixtures are obtained. Such mixtures usually contain carbon dioxide along with various amounts of hydrocarbons such as methane, eth-

In the figure the essential parts are a double-walled freezing chamber 1,spiral capillary tubes 14 and 20, a mercury reservoir 22, a pumping buret 2, and a collecting bnret 3. In operation, the apparatus is first completely evacuated. A sample of the gas to be analyzed is then admitted to the freezer and allowed to fill capillary 14 and a portion of bulb 18 by displacing the mercury therein. A freezing mixture 28 is then placed in the freezing compartment. The freezing agent may be liquid air or liquid oxygen. The less volatile constituents are thus frozen out of the gas mixture and adhere to the walls of capillary 14. The parts which are still gaseous are drawn over into pumping bnret 2 by lowering bulb 24 which, of course, lowers the mercury level in buret 2. For complete separation the freezing operation must be repeated several times. When it is completed, the remaining gases are drawn over into buret 2 and the mercurv in connectine " tube 15 is drawn UD far enoneh so that it freezes and forms a seal. The final staxe includes draw in^ off the gaseous constituents into collecting bnret 3 f o r further analysis. By choosing the freezing substance different gases may be frozen out of the original mixture. No. 2,370,703. Wladimir M. Zaikowsky, Pasadena, California, assignor to Consolidated Engineering Corp.

How would you mensure the thickness of a continuously moving white hot sheet of steel coming from a rolling mill at the rate of 20 miles an hour? A new de-elopment permits the measurements to be token by means of X-rays. With an X-ray machine below thesteelandanx-ray intensity rneteraboue, an indication of the steel's thickness con be read ot any moment.

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