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T H E JOL-RNAL OF I N D C S T R I A L A N D EXGINEERIhTG C H E M I S T R Y
and we have prepared a number of mixtures which are in steady use a t our plant for performing this operation upon various machine parts which we are using. It works extremely rapidly a t very low temperatures, but we have not yet succeeded in overcoming certain fads in large scale use of this material, and it has not met with any general introduction. We found that the case hardener is more concerned with the color of his hardening powders than he is with the actual work they perform, and as the colors and odors of our cyanamid products are rather fast we have not found it interesting t o us to meet some of these peculiarities of the case-hardening trade. While abroad I saw these case-hardening materials being prepared by the hundreds of tons for use in the manufacture of armament and war materials, and the small factory engaged in their production has been swamped with orders ever since its inception. The arc processes have shown themselves capable of producing nitric acid or nitrates. Cyanamid itself is an entirely different product, but it is quite easy to produce ammonia from it, and there has recently been evolved abroad a most successful method of oxidizing this ammonia to nitric acid, so that in case of competition with the Birkeland-Eyde process we are not entirely limited to the fixation of nitrogen, but can furnish this nitrogen in exactly the same form that the arc processes can, and a t considerably less cost. Our raw materials are cheap-coke, limestone, air. We use only one-fifth the electrical power that the arc processes do per unit of nitrogen fixed in the form of Cyanamid, respectively ammonia, and by the addition of a very small percentage more power we can convert our Cyanamid into nitric acid. We require about the same quantity of labor to fix a unit of nitrogen in Cyanamid as the arc process does in nitric acid, but since there is only a small fraction more labor used to transform Cyanamid nitrogen into nitric acid we do not feel this is a great handicap when one considers our smaller power consumption. On the American continent where water power is so expensive and so scarce this difference readily off-sets the additional labor necessary t o make nitric acid from Cyanamid. Further, our Cyanamid is easily transported and can be changed to ammonia or nitric acid a t the end of its journey a t the expendi-
5'01. 7 , NO. 5
ture of a very small amount of steam and labor, so t h a t we have the additional advantage in transportability of stable raw material, and subsequent conversion a t the point of direct use. These commercial transformation units are small, and can be set up to supply even small amounts of ammonia or acid in a quite cheap and efficient plant. Practically all sulfuric acid plants in Germany have installed them since nitrate disappeared from trade. There is no comparison between the initial investment required for a Cyanamid plant and for an arc plant, if one includes power development. The Cyanamid plant, per unit of nitrogen fixed, requires a n investment of only about one-fourth that required by the arc process, and for a Cyanamid-ammonia plant about one-half that required by the Haber process. Even the combination of the Cyanamid-ammonia-nitric acid process requires a n investment of only one-third to one-half that for the arc process. In each case we are assuming exactly the same quantity of fixed nitrogen in the forms above designated. Where electrical power is expensive, as in the United States, there is no question regarding the superiority of the Cyanamid process for the fixing of atmospheric nitrogen, particularly for fertilizer purposes, and we eventually hope that the future development of our nitric acid process will enable us to compete in every line of nitrogen compounds with all other competitive sources. I have brought with me some moving pictures of our Siagara Plant, showing the arrangement of the whole and some details of the various units comprising it. It is manifestly impossible in a plant such as ours to obtain pictures of every operation, but I have brought the most representative views of the operation of fixing nitrogen. When one considers that we have a t Niagara a 1 2 kiln lime plant, 25,000 H. P. of carbide furnaces. a liquid air plant which was the largest in the world a year ago, a gas plant of sufficient size to serve the average town of z 5,000 inhabitants, a nitrogen retort plant, a n ammonia refrigeration plant, a causticizing plant, a nitrification plant, a hydration plant, and innumerable crushers, mills, silos and feeding machinery, it is rather difficult t o include them all in a few hundred feet of motion picture film.
CURRENT INDUSTRIAL NEWS B y A I . I,. HAMLIN
RECOVERY OF TOLUENE FROM GAS
In the course of the proceedings a t the conference on coal supplies held in Manchester in February, hlr. Macintosh Williams, who attended on behalf of the War Office Committee on the Supply of High Explosives, referred to the shortage of toluol and to the action taken by the committee with the object of obtaining the necessary quantity to meet requirements. He stated that satisfactory arrangements had been made with the tar distillers; the coke-oven manufacturers were approached, and did what they could. Subsequently an appeal was made to the larger gas undertakings to make arrangements to wash the toluol out of their gas, and, in case of need, replace it with benzol if this was necessary to preserve the illuminating and calorific power. They thought that if the wash oil employed for washing or scrubbing the gas was first pre-benzolized, it would take up only the toluol content of the gas and leave the benzol content to a certain extent intact. Birmingham had made experiments, and found that if the oil was pre-benzolized to the extent of 5 per cent, it was possible to extract nearly 80 per cent of the toluol content, and leave more than two-thirds of the benzol content still in the gas. If this were the case, it would materially assist the Government. Dr. W. B. Davidson, the engineer-in-charge of the Nechells station of the Birmingham Gas Department, had drawn up a sketch of the plant which he thought might be adopted to effect
the object in question. There is from twenty t o forty times as much toluene in the gas made from a ton of coal as there is in the tar produced from this bulk of raw material; and probably a t least 2 lbs. of pure toluene, making 4 lbs. of trinitrotoluene, can be readily recovered per 10,000cubic feet of coal gas. The stream of cooled debenzolized oil coming from the crude still is mixed with a small stream (about j per cent by volume) of benzol in tank TI and is then pumped a t the required rate (about 1300 gallons per hour) by pump PI to the top of scrubbers S 3 ; then by pump P2 from the bottom of Sa to the top of SZ; and finally by pump Pa from the bottom of SZto the top of SI. The oil now benzolized runs from the bottom of SIto the storetank T,. whence i t is pumped by P4 in a continuous stream through the heater HI, where heat interchange takes place between the cold oil and the hot oil leaving the crude still; then through the exhaust steam heater H2; then through the superheater Ha (containing a closed high-pressure steam-coil) to the crude still, where i t meets a current of high temperature steam, which deprives it of its crude benzol. The hot debenzolized oil is drawn off and caused to flow first through HI, and afterwards through a water condenser, CI, to the store-tank TI. The crude benzol vapors and steam are condensed in the water condenser Cz. The condensate flows to a receiver, R, whence it passes through a separator, the crude benzol being stored in the tank T,.
N a y , 1915
ELEVATION
T H E J 0 C R 9.I L 0 F I S D t 7 ST RI A L A N D E GI il: E E RI X G C H E M I S T R Y
THE
AND P L A l O F P L A K T FOR
EXTRACTION OF TOLUOL F R O M C O A L GAS-CAPABLE O F DEALING W I T H 800 Cu. FT. OF GAS PER DAY
A charge of about 1600 gallons of crude benzol is pumped by
Psdaily into the intermediate still where it is distilled by steam with the production of commercial benzol, commercial toluol and residual xylol and heavier oils. The commercial benzol is mixed with the wash oil, together with an additional quantity corresponding to the amount of toluol, etc., permanently removed from the gas. The commercial toluol is redistilled in a second still for the production of pure toluol. If the wash oil contains much naphthalene, it may be necessary t o return the xylol t o the gas, to prevent naphthalene stoppages in the district services. Gas oil will probably prove the most suitable oil for washing purposes, as it is generally ready to hand, contains no naphthalene and readily absorbs crude benzol. ~~
COST OF HYDROGEN GAS I n the course of the report of the British Comptroller and Auditor-General upon the Army Services appropriation account for the year ended March 31st last, which has been issued as a IVhite Paper, it is stated, in connection with expenditure at the Royal Aircraft Factory, that the cost of hydrogen gas showed an increase from $4.60 per 1000 cu. f t . in 1912-13 to $5.2j in 1913-14 [ J . Gas Lighting, 129 (191j), 4421. The output during t h e latter year was 2,023,607 cu. f t . as compared with 3,493,296 c u . f t . in 1912-13. GAS PROGRESS IN TURIN Notwithstanding the cost of coal and the outbreak of war, the Societa Anonima dei Consumatori di Gas-Luce, of Turin, Italy, states in its last annual report that gas affairs in that city are not only satisfactory but progressive. During the twelve months covered by the report, 21,7j0,46j cubic meters of gas were sold, which was a n increase of over 500,ooo cubic meters on the sales of the previous year. Gas-meters, likewise, have gone up in number-from 45,000 to 47,000. I n spite of keen electricity competition, the board of directors are convinced the future offers splendid prospects-especially in respect of the use of gas for heating purposes. Early in 1913 the price of coal was Sj.75, c. i. f . a t Savona. Later it rose t o $6.12, while during 1914, it dropped first to
T O N S O F C O A L OR
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~o.ooo,ooo
$5.40 then t o $j.oo. The Company was fortunate enough, at the outbreak of war, t o have their coal stores well stocked -even considerably above their contractual obligations with the municipality of Turin. All the coke is readily sold; so much so that efforts are being made to use, in the producers, coke dust mixed with tar, and coke dust briquettes made on the gasworks. Old scrubbers have been replaced by modern vertical centrifugal washing apparatus, and old benches of retorts have given place t o new. EXPLOSION FROM A DEFECTIVE GAS SERVICE GOVERNOR A communication by SIr. Reinhard, manager of the Leipzig Gas Company was published in the Journal f u r Gasbeleucitti~ng of Jan. goth, describing an explosion that occurred in a spacious
I
cellar of a bookseller’s establishment and a basement restaurant adjoining it. The explosion and resultant fire were attended with loss of life. There were six gas-meters located in the cellar for supplies t o various parts of the whole building-four being jo-light meters in a n open cupboard, one of the remaining two
