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New Bench Scale Coal Hydrogénation Unit Raymond W. Hiteshue of the Bureau of Mines told a high pressure symposium at the Division of Industrial and Engineering Chemistry that this new process uses the most severe conditions ever imposed on coal to convert it to gaseous product: 6000 p.s.i.g. and 800° C. And its done without a catalyst. The unit is semicontinuous. The coal charge can b e heated and cooled instantly. The reason is a tubular reactor with a built-in low voltage, highamperage circuit. Hence, coal-hydrogen studies can b e evaluated rapidly . Here's how it's done: • Place coal in the reactor. • Feed hydrogen through it at 600O p.s.i.g • Heat t h e reactor and charge electrically (heater time can b e varied from one to 15 m i n u t e s ) . • Take off hydrocarbon vapors, gases^ and excess hydrogen to a condenser receiver and then into a gas holder. • Reduce reactor and charge to room temperature with a water quench.
catalyst, some 6 5 % of t h e coal is decomposed. This rises to 9 0 % after 15 minutes. With ammonium molybdate as a catalyst, the gas yields are only 70% after this time period. As for p r o d u c t s formed after the first minute, 4 0 % of the coal becomes gaseous hydrocarbon—mostly methane and some ethane. After 15 minutes, the yield doubles. Liquid production is a little different. Up t o 9% is converted in the first minute, and this figure remains constant for t h e next 14 minutes. All told these bench scale results look good. Now the bureau is planning a small continuous unit. However, says Hiteshue, this new method does not have any immediate commercial use. I t is, though, a new approach to t h e long studied problem of converting coal to liquid and gaseous products.
Ethyl Has New Way to TEL
T h e whole operation is shielded in a. concrete cubicle.
Newly found method opens route to many metalarganics, hints future company plans in this field
High molecular weight oils and unreacted solids are recovered by benzene and conventional separation methods. • The Results. Quite significant, Hiteshue points out, the conversion i s higher without a catalyst than with one. H e adds, this is a mystery and is contrary "to t h e rule." It is now the subject of further research aimed to explain this conversion phenomenon. W i t h or without a catalyst, the coal conversion to liquids and gases varies with the heating time, b u t it is most rapid in the first minute. Without
Ethyl Corp. research workers have found a ACS NATIONAL MEETING completely new Industrial & way to make tetraethylEngineering lead. T h e new Chemistry method could b e a hint to Ethyl's future plans in the metal-organic field, for i t opens a new route to m a n y such products. Today, T E L is the only metal-organic made by the firm. But the new process is still in the lab stage,
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and Ethyl has no plans yet to commercialize it. Ethyl's S. M. Blitzer told a Symposium on Metal-Organic C o m p o u n d s b y the Division of Industrial a n d Engineering Chemistry the m e t h o d is totally different from any ever used or proposed to make T E L . It involves reactions between nonhalide lead compounds and metal-organies such as triethylaluminum, diethylzinc, or ethylsodium. Many lead compounds can be used: lead sulfate, lead oxide, lead acetate, o r other organic and inorganic salts. Significant here, says Blitzer, is t h a t t h e usually inert sulfide a n d oxides react with metal-organics to make T E L . Even more unexpected, h e continues, the primary organolead reaction product is completely ethylated. Today Ethyl uses a T E L process that involves sodium-lead alloy a n d ethyl chloride. Reaction conditions are mild: temperatures b e l o w 100° C ; pressures less than 10O p.s.i. The new process is also a mild, one: temperatures usually run from room to 100° C. But pressure i s not needed. The reaction takes p l a c e at moderate to rapid rates. T E L is often formed in yields u p to 8 0 % and higher. In some cases yields of 30 to 40 ^c can b e o b tained at temperatures d o w n t o —24° C . These high yields a r e significant, Blitzer points out. Today's conimercial process converts only 25 % of available lead to T E L . U n r e a c t e d lead is r e cycled back to the processing unit. The n e w method can assure anywhere from 50 to 100% conversion, thus r e ducing the recycle volume. Still more comparisons: It does away with chlorine. Sodium-lead alloy production is avoided. I n m a n y cases the reducing metals—for example aluminum, zinc, or sodium—can b e recovered and reused. In today's process, sodium is converted t o dilute brine and discarded. The trick to good reactions, adds Blitzer, is to use solvents. Hydrocarbons, amines, ethers, esters, and chlorinated hydrocarbons will improve r e action control and also t h e contact b e tween reaetants when o n e or both are solids under normal conditions. As a rule, organic salts react more readily than inorganic ones— the better the solvency, the faster the reaction. Lead formate is a good example, explains Blitzer. W i t h diethylzinc in toluene, T E L was made i n 9 5 % yields. The reaction took place a t 111° C. for 1.5 hours. In another case, lead formate and ethylsodium in h e p t a n e gave yields up to 1 0 0 % . • Good Yields f r o m Inorganics. Many metal-organic c o m p o u n d s a n d inorganic lead salts m a d e T E L in gcod
PRODUCTION yields b u t not as h i g h as those m a d e from organic lead salts. With lead sulfide a n d a mixture of emylhthium a n d ethylsodium. t h e yield was S i % . Again conditions w e r e mild: temperatures, 2 5 e C-; time 4 . 5 hours. And lead sulfide a n d sodiuxnzinctriethyl gave 3Q% yield a t — 24 c C. a n d 9 hours time. M a n y more reactions a n d results can b e cited, continues Blitzer. Even mixed c o m p o u n d s such a s lead oxide a n d organic acid lead salts w e r e tried. I n all cases T E L w a s formed—often in yields h i g h e r than today's commercial T E L process. • Future Plans. H o w far Ethyl will g o with this new process is open to question n o w . T h e r e is more research t o be done ? adds Blitzer— for example, just w h a t metal-organic compounds and w h a t nonhalide l e a d compounds will give t h e best results u n d e r process conditions. Variables must b e looked into a n d then t h e best possible methods put into pilot plant study for more developm e n t work—not only for T E L but for other metal-organics as well. This w o u l d include p r o d u c t s made from tin. cadmium^ mercury, a n d other elements . I t is conceivable t h a t Ethyl plans to b r o a d e n its metal-organic product line —now limited to just T E L . Recently, t h e firm a n n o u n c e d triethylalurninuxn in d e v e l o p m e n t amounts. It is a starting material for t h e n e w T E L process. Also, E t h y l looks for continued T E L g r o w t h . I n the p a s t year a subsidiary-. E t h y l of Canada, o p e n e d a T E L plant a t Sarnia, Canada. E t h y l is now buildi n g a n e w T E L plant at Pittsburg. Calif. I t is slated to go "on stream'* in mid1958. Also, last year the company acq u i r e d a plant site at Joliet, 111.—possib l y for another tetraethyllead plant. W h e t h e r t h e n e w T E L process will fît in here cannot b e answered now. T h e important point, concludes Blitzer, i s t h e n e w process a n d its chernistry. I t gives Ethyl another way to T E L arid other metal-organics—if the company cares to s;o that w a v .
tives of D o w Chemical's continuous recycle polymerization. A n d , Alden W . H a n s o n a n d Robert L. Zimmerman told t h e Division of Industrial and Engineering Chemistry last week, their process meets these objectives. W i t h it, t h e y say, they can p r o d u c e copolymers w i t h a n y compo sition regardless of t h e reluctance of one ingredient to combine with t h e other. F o r example, they have m a d e a styrene—maleic anhydride copolymer of 55-45 ratio a n d acrylonitrile-styrene colpolymers of 5, 10, a n d 15
