British Chemists Study Possibilities of Coke-Oven Gas C . H . S. T u p h o l m e , 6, H a m i l t o n Gardens, N . W. 8, London, E n g l a n d B R I T I S H INDUSTRIAL CHEMISTS h a v e followed w i t h keen interest continental development in t h e better utilization of cokeoven gas, a n d a great deal of research work i s being d o n e t o t u r n the increasing volume of coke-oven gas to b e t t e r account. R e cently, t h e Utilization of Coal Committee of t h e Institution of Mining Engineers made a survey of the possibilities i n which it is pointed o u t t h a t coke-oven gas in B r i t a i n is used mainly for heating t h e ovens, as t o w n s ' gas, or for enriching blast-furnace gas or producer g a s t o be used for steel-melting or r e h e a t i n g ; o r is used for power production, either b y being b u r n t under boilers or in gas engines. Some is n o t utilized. The sale of coke-oven gas for towns' supply h a s increased rapidly d u r i n g recent years. I n 1922, the a m o u n t of coke-oven gas sold to g a s u n d e r t a k i n g s was 3636 million*cu. ft.; b y 1928 it h a d increased t o 6375, a n d b y 1933, t o 15,941 million c u . ft. I t is recorded t h a t in 1933, 137,492 million cu. ft. of gas were produced a t coke ovens a n d 22,181 million cu. ft. were sold, t h e difference between t h e latter figure and t h e volume sold t o gas undertakings d u r i n g t h e same year (15,941 million cu. ft.) representing direct sales to large consumers. In 1928, t h e coal owners of South Yorkshire m e t to consider t h e question of cooperating t o promote the sale of coke-oven gas and, subsequently, a s a result of various schemes p u t forward, t h e South Yorkshire Gas Grid Co. was formed i n J a n u a r y , 1930. I n March, 1930, t h e D e p a r t m e n t a l Committee of the Board of T r a d e on Area G a s Supply issued a report in which plans were outlined for t h e collection of gas from a n u m b e r of coke-oven p l a n t s in South Yorkshire through a "grid" of mains. T h i s scheme, which followed closely t h a t of t h e South Yorkshire G a s Grid Co., h a s been adopted with some modification. Other schemes for t h e utilization of coke-oven gas involve t h e separation of some of its constituents, a s is done, for example, in France and Belgium, or its chemical t r e a t m e n t t o produce liquid fuels. T h e survey referred t o briefly reviews such schemes. The principal constituent of coke-oven gas is hydrogen, which is becoming increasingly valuable a s a chemical reagent. T h e feasibility of using hydrogen from coke-oven g a s for such purposes as hydrogénation naturally d e p e n d s primarily o n t h e cost of its separation in comparison with that of obtaining it in other ways, such a s , for example, from water gas. O n this subject, figures have been published in relation t o t h e production of hydrogen for t h e synthesis of a m m o n i a , in connection with a pioneer installation b y t h e Union Chimique Belge at Ostend. The figures were: (1) From water gas (from coke a t 19 s. 6 d. per ton) 8.7 d. per 1000 cu. ft. (2) From water gas (from coal a t 20 s. 6 d. per ton) 8.35 d. per 1000 cu. ft. (3) From coke-oven gas (at 5.45 d. p e r 1000 cu. ft.) 9.27 d. per 1000 cu. ft. The residue from the coke-oven gas, after removal of t h e h y drogen, c a n be credited, according to i t s t h e r m a l value, at a price equivalent t o t h a t of t h e original gas. Since only a b o u t 30 per cent of the t h e r m a l value of coke-oven gas, though a b o u t half its volume, is due t o hydrogen, the credit for the residual gas is high. I n Belgium a n d France, a considerable synthetic a m monia i n d u s t r y h a s been developed at a n u m b e r of small plants, using coke-oven gas as t h e source of hydrogen. The possible use of hydrogen from coke-oven gas for a m m o n i a synthesis in Britain can probably be ignored, b y reason of t h e large scale o n which ammonia synthesis is a l r e a d y carried o u t a t Billingham b y Imperial Chemical Industries, L t d . Similarly, t h e home d e m a n d for methanol is a t p r e s e n t limited and is p r o b a b l y already sufficiently supplied. Consideration should, however, says t h e committee, b e given to hydrogénation processes in general, t o determine w h e t h e r t h e development of existing industries can b e encouraged near potential supplies of cheap hydrogen. Alternatively, pure hydrogen produced a t a coke-oven plant could be t r a n s p o r t e d and might b e delivered a t hydrogénation plants (e. g., at margarine a n d soap works) more cheaply t h a n it can b e produced locally. In Germ a n y special railway cars are built for t h e t r a n s p o r t a t i o n of 500 . cylinders containing a b o u t 100,000 cu. f t . of hydrogen. In particular, a t t e n t i o n should b e given to t h e practicability of installing, i n connection with coke-oven plants, plants for t h e hydrogénation of t a r products, such as creosote oil. The t o t a l ''residual'' gas (i. e., t h e mixture of gases from which the hydrogen h a s been removed) h a s a calorific value a b o u t 25 per cent greater t h a n t h a t of the original coke-oven gas and has been highly purified during t h e process of r e m o v a l of the hydrogen. I t , therefore, has a n enhanced value for power and heating purposes, for it could be delivered direct into m a i n s for industrial use. i t should b e noted, however, t h a t during t h e separation of h y drogen from t h e coke-oven gas, t h r e e s e p a r a t e condensates h a v e
been o b t a i n e d — t h e so-called carbon monoxide, methane, a n d ethylene fractions. E a c h of these, if collected separately, h a s special uses. T h e carbon monoxide fraction (containing a b o u t 18 p e r cent of carbon monoxide) is used on the Continent for the synthesis of methanol. T h e m e t h a n e fraction (containing about 7 5 per cent of m e t h ane) h a s a calorific value of a b o u t 815 B. t . u. per c u . ft. a n d could therefore be used t o greater a d v a n t a g e than t o w n s ' g a s compressed in cylinders for automobiles. Use can also be m a d e of t h e m e t h a n e for t h e production of acetylene, from which acetone, acetic acid, a n d acetate solvents can be prepared. T h e ethylene fraction has greater possibilities. I t s calorific value is a b o u t 1580 B. t . u. p e r cu. ft., so t h a t , if it were used a s compressed gas for a n automobile, t h e t o u r i n g range of t h e c a r would be a b o u t three times a s great for t h e same capacity of cylinders, as when t o w n s ' gas i s used. Alternatively, t h e ethylene fraction could be pyrolyzed, when i t would yield about 2.5 gal. of light m o t o r spirit per 1000 c u . ft.; or polymerized, a t a lower temperature b u t a t a higher pressure t h a n is required for i t s pyrolysis, when it would yield a b o u t 7 gal. of light motor spirit per 1000 cu. ft. Or, a s is done, for example, a t Bethune, t h e ethylene a n d propylene could be absorbed i n sulfuric acid a n d converted into ethyl and propyl alcohols. In the presence of a suitable catalyst a t a low temperature a n d a t atmospheric pressure, hydrogen and carbon monoxide react t o produce a mixture of hydrocarbon oils (mainly parafhnic), a c cording t o F . Fischer's " s y n t h e n e " reaction. This reaction r e quires t h e hydrogen a n d carbon monoxide t o be present in t h e volumetric proportions of two of hydrogen t o one of carbon m o n oxide, proportions conveniently obtained b y adding water g a s t o coke-oven gas. T h e process is being developed in Britain. 7 5 T H BIRTHDAY OF P O N Y E X P R E S S OBSERVED VIA AIR EXPRESS W I T H A D I P of i t s wing shortly after 7 P. M. o n April 3 , a m u l t i motored, 10-passenger t r a n s p o r t plane roared out of t h e airport a t St. Joseph, M o . Some 10 hours later, its cargo was delivered a t t h e a i r t e r m i n a l in Sacramento, Calif.,—some 2000 miles away—having traversed t h e route of America's famed P o n y Express which was begun in a flurry of dust, almost t o t h e h o u r , three quarters of a c e n t u r y before. Probably n o more spectacular proof of t h e advance of t r a n s portation could be found than t h e contrast of a few hours' leisurely flying t o d a y a n d t h e 8 t o 10 days of terrific riding required t o transport a light saddle bag of express m a t t e r between t h e rail terminus a t St. Joseph a n d t h e b o a t landing a t Sacramento—the last remaining link in America's transcontinental system 75 years ago. T o d a y t h e Air Express Division of Railway Express Agency—modern development of t h e early express companies which operated stage-and-pony express service—loads cargoes of packages on commercial airline routes t h r o u g h o u t the N a t i o n for "2000-miles o v e r n i g h t " delivery, while within the m e m o r y of m a n y old-timers it required some 800 ponies, hundreds of relay stations, a n d a picked group of expert riders t o maintain a t r a n s portation service of t h e same distance which a t best could t r a n s port only a few pounds over t h e dangerous trail to t h e Pacific Coast. SAN BERNARDINO PROVING GROUND T H E E T H Y L G A S O L I N E C O R P . h a s a n n o u n c e d t h e selection of
San Bernardino, Calif., a s the base of operations for experimentation in automotive performance. A careful survey of t h e country showed San Bernardino t o h a v e within t h e a r e a of which it is t h e center a greater diversity of climatic and geologic conditions e n -r countered in e v e r y d a y a u t o m o t i v e operations than exist in an} other region of continental United States. I n southern California it was found t h a t Nature has assembled t h e climates, topography, t e m p e r a t u r e s , altitudes, a n d formations that a r e widely diffused over other lands. I n this new n a t u r a l laboratory, e n gines, fuels, a n d other automotive equipment destined for use in every quarter of t h e globe will undergo t h e m o s t grueling workouts. A caravan of ten trucks, tractors, and pleasure cars representing a n investment of S 100,000 and equipped with improved t e s t ing devices costing approximately $10,000 p e r vehicle, has been transferred from D e t r o i t t o San Bernardino to become t h e nucleus for a great proving fleet for automotive research. T h e caravan, carrying more t h a n 20 persons, followed the northern route through Nebraska, Wyoming, a n d U t a h , then crossed the desert country of southern Nevada a n d southern California.
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