Nov., 1915
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
expense, either, I desire t o emphasize, of sacrificing t h a t very essential of all mechanical training-fundamental general principles to specialized details. NIAGARA FALLS, ONTARIO, CANADA
CONTRIBUTIONS OF THE CHEMIST TO THE EXPLOSIVES INDUSTRY By CHARLESE. MUNROE Explosives Expert, George Washington University
The explosive industry is essentially a chemical industry and is most efficiently conducted under close chemical supervision. It is true t h a t a large part of the explosives used or proposed for use in commerce are mixtures of various components, t h a t variations in the proportions of the components or modifications of the physical conditions of the components, or of the product, may fit i t better for certain of the multifarious uses to which explosives are put, and that this has given large opportunities for the exercise of empiric ingenuity which practically controlled the industry for centuries; but modern developments have proven t h a t these mixtures can be most economically, uniformly and satisfactorily produced when their manufacture is supervised by skilled chemists who prove the degree of purity of each ingredient and, by a systematic scientific series of tests, determine quantitatively the characteristics of the product. As a fact, while the empiricist has dominated the industry up to recent times he has nevertheless benefited from the altruistic services of the chemist, for gunpowder, the mixture which almost alone served man’s purpose as an explosive through five centuries, was brought to the attention of western nations by Roger Bacon, whom E. von hleyer includes as a n alchemist in his history of chemistry, and it was brought to a higher state of usefulness and reliability through the researches of Lavoisier, Berthollet, Gay Lussac, Violette, Chevreul, Bunsen, Linck, Karoyli, Debus, and other chemists, and a variation in the oxidizer was wrought when Berthollet proposed in 1785 the substitution of a chlorate for the nitrate. With the discovery of picric acid by Woulfe in London in 1 7 7 1 , its confirmation by Hausmann in 1788, its identification
94 5
as trinitrophenol by Laurent in 1 8 4 3 and the demonstration of its explosiveness per se by Sprengel in 1873 began the era of strictly chemical explosives. This was followed in 1800 by the discovery of mercuric fulminate by Howard, and the elaborate investigations of the fulminates by Liebig and his students; by the discovery of guncotton and the cellulose nitrates in 1845 by Schonbein and in 1 8 4 6 by Bottger; by the discovery of nitroglycerin by Sobrero in 1 8 4 6 ; by the discovery of diazo compounds by Griess in 1 8 5 8 ; and by the discovery of hydronitric or triazoic acid and its salts by Curtius in 1 8 9 0 . With the demonstration by Berthelot of the explosiveness of other nitrosubstitution compounds than picric acid there came a widely extended and constantly increasing use for them; and the number of different compounds made use of is constantly growing for while the cellulose nitrates, with nitroglycerine, are playing the r61e of propellants, the nitrosubstitution compounds are the explosives which are being made use of in the high explosives shell now working such devastation in the present war. I believe I have said enough to make it obvious that only by the liberal employment of trained chemists can this industry be continued or extended, and in recent years this view has been accepted and followed by manufacturers. It may be worth while to recall here t h a t when the Census of the Chemical Industries was taken in 1900 a n inquiry was made as to the number of chemists employed, because it was then recognized that this afforded a criterion by which to determine the intelligence and foresight with which the businesses were conducted. As shown in Bulletin No. 2 1 0 of that Census there was reported but 276 chemists employed in 1740 establishments then reporting, and that but 32 chemists were employed in the 97 explosives works from which returns were secured. It is not known what effect, if any, this inquiry had but it is understood that a t present a single explosives company in the United States employs alone many times this number of chemists. This improvement is gratifying to record but it should serve only as a n example to be emulated. WASHINGTON. D. C.
ORIGINAL PAPERS THERMAL REACTIONS OF PETROLEUM HYDROCARBONS IN THE VAPOR PHASE’ B y WALTERF RITTMAN Received Sept. 8 , 1915
O n e of t h e m o s t widely s t u d i e d and i m p o r t a n t c h e m i c a l p r o b l e m s of t h e p r e s e n t d a y i s t h e t h e r m a l d e c o m p o s i t i o n o r “ c r a c k i n g ” of p e t r o l e u m h y d r o c a r b o n s . A c o n s i d e r a b l e n u m b e r of i n v e s t i g a t i o n s h a v e b e e n u n d e r t a k e n a l o n g t h i s line, m o s t of w h i c h were c o n d u c t e d w i t h t h e p r i m a r y i n t e n t i o n of d e v e l o p i n g c o m m e r c i a l processes. T h e d a t a t h u s o b t a i n e d h a v e b e e n necessarily of a r a t h e r special c h a r a c t e r and, i n a d d i t i o n , a r e n o t p a r t i c u l a r l y a v a i l a b l e t o t h e scientific world. In v i e w of t h e wides p r e a d n e e d for c l e a r - c u t a n d c o m p r e h e n s i v e i n f o r m a t i o n c o n c e r n i n g t h e “ c r a c k i n g ” r e a c t i o n a series of e x p e r i m e n t s has b e e n o u t l i n e d f o r t h e p u r p o s e of s t u d y i n g t h e problem consistently a n d impartially i n all its p h a s e s . T h e first e x p e r i m e n t s 2 w e r e c o n d u c t e d i n c o n n e c t i o n w i t h t h e p r o b l e m of oil-gas p r o d u c t i o n a n d w e r e l i m i t e d t o s u c h c o n d i t i o n s as m i g h t a p p l y i n t h a t 1
Published with the permission of the Director of the Bureau of Mines. THISJOURNAL, 6 (1914), 383 and 472.
* Whitaker and Rittman,
field. A t t e n t i o n w a s g i v e n t o t h e influences of t e m p e r a t u r e , pressure a n d concentration o n t h e e n d p r o d u c t s of t h e r e a c t i o n , a m a x i m u m of c a r e b e i n g b e s t o w e d u p o n t h e p r o p e r t i e s of t h e e v o l v e d gases. Liquid p r o d u c t s were examined o n l y w i t h regard t o general physical a n d chemical properties.
I n t h e p r e s e n t e x p e r i m e n t s it has b e e n f o u n d u n n e c e s s a r y t o g i v e m o r e t h a n a m i n i m u m of a t t e n t i o n t o q u a n t i t a t i v e relations a m o n g gaseous products. T h e r e s u l t s of t h e earlier e x p e r i m e n t s were so definite a n d so e x a c t l y i n a c c o r d w i t h t h e o r e t i c a l c o n s i d e r a t i o n s that little h a s been a d d e d t o t h e m i n t h e present c o n n e c t i o n . It has b e e n possible, h o w e v e r , t o l e a r n f a c t s of the g r e a t e s t i m p o r t a n c e c o n c e r n i n g l i q u i d p r o d u c t s of t h e c r a c k i n g r e a c t i o n a n d , i n a d d i t i o n , valuable information h a s been obtained regarding t h e c o u r s e a n d m e c h a n i s m of t h e process. T h e r e s u l t s a t h a n d h a v e l e d t o t h e following conclusions w i t h r e g a r d t o t h e c r a c k i n g r e a c t i o n : I-The n a t u r e , b o t h p h y s i c a l a n d c h e m i c a l , of an oil is of s e c o n d a r y i m p o r t a n c e , c o m p a r e d w i t h t h e influence of t e m p e r a t u r e , t i m e , a n d pressure, i n cont r o l l i n g t h e p r o d u c t s of t h e c r a c k i n g r e a c t i o n . U n d e r
