Hopes Brighter for Gas Substitute N e w process combines t w o o l d ideas a n d m a y b e most economical way to high B.t.u. g a s Put
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ideas °wn ,together and they can add up to what GdS&Fuel may b e the most Chemistry economical route to high B.t.u gas to substitute for natural gas. In this case it means a d d a pretreatment step to a direct hydrogenation process. This leads to chars that react quickly and makes a high methane content gas which rates 9 0 0 B.t.u.'s. This gas will perform like natural gas, although natural rates 1000 B.t.u. Specific gravity explains the similarity. The 900-B,t.u. product is lighter; hence, the user really ends u p with the same number of B.t.u. delivered to the burner, K. C. Channabasppa and H. R. Linden, Institute of Gas Technology (working under an American Gas Association sponsorship) told the Division of Gas a n d Fuel Chemistry. • A Two Step Process. The 900B.t.u. gas is made from bituminous coal through a two-step, fluid-bed process which involves a pretreatment step a n d then a direct hydrogenation to convert to gas. Both ideas are well known, b u t no one thought it worthwhile to couple the two into one continuous process, explains Linden. Pretreating is really the important part. I t prepares the coal for hydrogenation. In so doing, carbon oxides and hydrocarbons, such as benzene, toluene, and xylenes, are removed. (If a large volume plant were built, it could b e another source for these chemicals.) Pretreating leaves a char which will b e much more reactive (to hydrogen) a n d will not agglomerate—a vital factor in a fluid-bed process. In t h e lab, pretreatment takes about 30 to 6 0 minutes, depending upon the coal used. Temperatures do not exceed 700° F., explains Linden. T h e nonagglomerated char is then fed to the direct hydrogenation unit by hydrogen. Here, at temperatures between 1300° and 1400° F. and at pressures of about 1500 p.s.i., the char is converted to the high B.t.u. gas. This
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product has b e t w e e n 70 and 7 5 % methane, plus some ethane. Also important, a d d s Linden, t h e char left over from t h e hydrogenation step can be recycled to another unit. There, when t r e a t e d with steam or oxygen at 2500° to 3000° F. under pressures between 1O0 and 40O p.s.i., the char is converted to hydrogen for reuse in the process. Or as a n alternative choice, t h e c h a r can simply b e removed from t h e process for use as a fuel. • Supplements Pipelines. The high B.t.u. gas can supplement natural gas in transmission lines. This is best done where the pipelines pass t h r o u g h coal fields enroute to major market areas. Also possible, the process could b e a way to make natural gas for areas not now using it for industrial or domestic use. But the process does not promise cheaper natural gas. This is not t h e aim today, Linden points out. R e search workers are looking for ways t o get a gas substitute which will cost about the same as natural gas when natural gas supplementation will b e needed. And, many long term estimates predict there will b e a natural gas shortage some 20 years from now. Supply is not expected to keep pace with a n anticipated 509c rise in demands b y that time. Population g r o w t h is t h e big reason. More p e o p l e will use more gas and pay more for it. Today, natural gas prices average 4 0 to 4 5 cents p e r thousand cubic feet. By 1965 price will probably be n e a r 65 cents. Pretreatment, coupled with direct hydrogenation may make it possible to have a substitute gas ready when natural gas gets short. It h a s economic advantages over another process thought of as a w a y to a natural g a s substitute: partial oxidation of coal followed by synthesis gas methanation. Reasons: • Direct hydrogenation eliminates oxygen needs.
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• It eliminates elaborate and expensive methods n e e d e d to purify the synthesis gas. • It generates less heat; hence, equipment costs c a n be reduced. Just how much of an advantage is a question now, a d d s Linden. It d e pends upon pilot plant studies, b u t rough calculations based on l a b work indicate a 15 to 259S? cost advantage.
Needed; Better Control NPFI sets up q u a l i t y control project. Its aim: savings for the fertilizer industry.
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"It is almost impossible to prepare a mixed fertilizer whose chemical Fertilizer & analysis will meet Soil Chemistry t h e manufacturer's guarantee of plant nutrients." This might b e hard to believe, but still it's true, says Vincent Sauchelli of the National Plant Food Institute. T h e reason for this, says Sauchelli, is that sampling and analysis methods haven't k e p t pace with n e w processes and types of plant foods. To help solve this problem, the N P F I has set up a research project in fertilizer quality control, Sauchelli told the Division of Fertilizer a n d Soil Chemistry. Under the NPFI project, fertilizer samples will be taken from a Baltimore plant and p u t through the mill by three state control chemists. All told some 476 chemical tests a n d 144 sieve analyses will b e made b y each lab. State laboratories in New Jersey, Virginia, and South Carolina have offered to cooperate. T h e d a t a from these tests will be used to do three things: c
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• Estimate how a fertilizer's analysis varies within a bag, and from bag to bag. • Measure the effect of different sampling methods. • Estimate the precision of the labs making t h e tests. The over-all goal of t h e project is to provide t h e fertilizer industry with a better quality control program. And w h y is a better program needed? Because, says Sauchelli, present inadequate methods cost the industry millions of dollars each year. • Overruns. Mixed fertilizers must live up to the analysis labeled on each bag. A manufacturer can't afford to have the plant food content of his product run less than t h e stated amount. So to b e safe, the makers formulate their products on t h e high side. This often results in an excess or overrun that is given away since t h e buyer pays only for the guaranteed content. Sauchelli estimates t h a t overruns cost the industry u p w a r d s of six million dollars each year. In just one SEPT.
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PRODUCTION mixed fertilizer plant studied by NPFI overruns cost almost $39,000 last year. This amounts to 60 cents on each ton of material turned out by this plant. Better quality control and more realistic tolerances, says Sauchelli, can cut down this loss without any sacrifice of service to the farmer. The NPFI quality control project was organized by an industry-government committee. Sauchelli is chairman, and among the members are people from International Minerals, Allied Chemical, Swift, U. S. Potash, USDA, and Canada Packers. Several state control chemists round out the group. The project will be linked with similar work at state laboratories and conducted in close association with USDA and die Association of Official Agricultural Chemists. NPFI provides all funds.
Terpenes Give Lubes, Picasticizers H e y d e n Newport's o x o path leads to long chain esters, with yields up to 75%
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halk U ACS P a,n1p 1 NATIONAL other role for the MEFriNtt oxo process. Using the oxo reaction on Organic terpenes, Heyden Chemistry Newport has come u p with a rash of long chain esters that can work as plasticizers and as components of jet lubricants. Key to the process is partial hydrogenation of the starting terpene alloocimene before going to the oxo step. The method was worked out by Carl Bordenca and Oliver G. Wilson of Heyden Newport in a program with Southern Research Institute. And it has since been successfully carried through the pilot plant stage, Bordenca told the Division of Organic Chemistry. Which esters are the best actors in jet lubes isn't being said just now. Evaluations are still going on. But among those that work as plasticizers, dimethylnonyl phthalate stands out as an excellent one for vinyl resins, claims Bordenca. Since it was discovered, the oxo reaction has reached industrial importance as a path to long chain alcohols. It's mainly a pressure reaction in which carbon monoxide and hydrogen are added to an olefin to give an aldehyde. Reducing the aldehyde yields the de-
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sired alcohol. But studying terpene hydrocarbons as raw materials for the process has been limited, says Bordenca. So even before its merger with Heyden last January, Newport set up a project at SRI to look into the oxo reaction as a source of new products from terpenes. The study at SRI was kicked off in 1950. Center of interest is aZZo-ocimene, an acyclic terpene. As a raw material, says Bordenca, aZ/o-ocimene is available in large quantities. Although it occurs in nature, the best way to get it is by pyrolizing a-pinene. • Polymerization Licked. According to Bordenca, allo-ocimenes structure is such that hydrogenation and polymerization occur during the oxo reaction. Here's where the partial hydrogenation step comes in prior to using the oxo process. With this step, by-products (mainly 2,6-dimethyloctane and an unsaturated C22 aldehyde probably formed by dehydrating an aldol condensation product) are cut down, and a higher yield of 4,8-dimethylnonanal is obtained. Without prior hydrogenation, yield of aldehyde is in the neighborhood of 50%. But if you hydrogenate over Raney nickel first, the oxo process gives a yield of about 75%, Bordenca claims. Best oxo feed stock comes from add-
ing 1.5 moles of hydrogen per mole of otto-ocimene, he says. Refractive index shows how much hydrogenation takes place. Here's how hydrogenation affects yields of aldehyde: H 2 /Moie AZZo- ocimene O.O 1.0 1.5 2.0
% Yield 53.0 75.2 77.0 74.6
• Oxo Step. The oxo reactions, as well as all hydrogenations, Bordenca explains, are done in an Aminco rocking autoclave. Dicobalt octacarbonyl made from cobalt carbonate is the catalyst. This catalyst and aZZo-ocimene are charged into the bomb, and a 1:1 carbon monoxide-hydrogen mixture added t o a pressure of 40OO p.s.i. Heating to 135° C. gives a pressure of 55O0 p.s.i. During two hours at 135° C , pressure drops to 300O p.s.i. When the bomb cools, the reaction mixture is steam distilled and the distillate fractionated to get 4,8-dimethylnonanal. Hydrogenating the aldehyde (again with Raney nickel) gives the corresponding alcohol, 4,8-dimethylnonanol. The esters are then made from the alcohol.
Pilot plant high pressure unit at Southern Research Institute is key to Heyden Newport's oxo process for jet lubricants and plasticizers, Oliver G. Wilson told Organic Division. Here, Wilson checks reaction conditions
