about 10 million light years of earth, emit the strongest radio signals from their centers. The abundance of OH in the two galaxies, relative to hydrogen—the most widely distributed element in space—is about one OH to every 1 million atoms of hydrogen, or about the same as in the Milky Way. In the Milky Way, chemical compounds have been observed in dust clouds in the interstellar regions. The dust shields molecules, or chemical combinations of atoms, from ultraviolet radiation that would otherwise rip them apart faster than they could form. Thus, although the galaxies M-82 and NGC-253 are too far away for dust clouds to be detected directly, Dr. Weliachew says that the OH there is probably protected by dust. The hydroxyl radical was first discovered in the Milky Way in 1962 by Alan Barrett of Massachusetts Institute of Technology. Since then about a dozen chemical species, including formic acid, methyl alcohol, and cyanoacetylene, have been detected in the interstellar space of the Milky Way, 10 of them in the past two years. ADVANCED COMPOSITES:
Graphite ribbon Pfizer may swell the ranks of companies vying for the market in reinforcement materials for making advanced composites. The firm has developed a pyrolytic graphite ribbon with the high tensile and modulus properties needed for advanced composites. Pfizer's graphite work is still at the reElectronmlcroscope study of graphite
search stage, but ribbon and film made by the company's process exhibit some unusual properties that could open the door to quick commercialization of the product. For example, Pfizer says, the ribbon is bidirectional; it has equivalent strength and modulus properties in one plane. Commercially available graphite and boron fibers are unidirectional, the company says. Dr. Robert W. Froberg, Earl E. Conabee, and Harold D. Stanley, of Pfizer's minerals, pigments, and metals division, told a conference on carbon at Lehigh University that the ribbon conservatively has a tensile strength of 100,000 p.s.i. and a modulus of 20 million p.s.i. The Pfizer scientists believe the ribbon is unique in that its modulus increases with increasing stress or strain and reaches a maximum at failure. Dr. Froberg tells C&EN that the ribbon is produced by vapor deposition of carbon on a hot surface. The carbon can be disassociated from any hydrocarbon gas, he adds. Ribbon or film made by the process has a density of 1.5 to 1.6 grams per cc. and can withstand temperatures of 5000° F. Reinforcing materials for advanced composites sell for high prices. Continuous graphite and boron fiber yarns and tow sell for about $250 a pound, although Great Lakes Carbon is marketing a continuous graphite tow at $100 a pound (C&EN, Feb. 15, page 14). Despite their high price tag, advanced composites will likely find many uses in aerospace and aircraft construction, rotating parts in industrial machinery, sporting goods, such as golf clubs, and pressure vessels. The potential for composites has lured many firms into the business of producing graphite and boron fibers. Celanese, Great Lakes Carbon, Hercules, Hitco (an Armco Steel subsidiary), Union Carbide, and Whittaker-Morgan produce graphite fibers in the U.S. Monsanto is negotiating to sell its graphite fibers venture in its New Enterprise division. Two U.S. firms—Avco and Hamilton Standard division of United Aircraft—produce boron filament fibers. In addition, Du Pont has in the research stage a completely organic fiber called PRD-49 that can be used to make advanced composites, and Hitco has in advanced development a graphite fiber broadcloth (C&EN, May 3, page 27).
NATURAL GAS:
Relief from synthetic gas Synthetic gas processes hold the answer to the natural gas shortage for Lummus Co. The Bloomfield, N.J., chemical construction firm, in an initial move into the field, will design and build units to produce synthetic gas from both coal and petroleum feeds. Lummus, a subsidiary of Combustion Engineering, Inc., says it has a contract from Consumers Power Co., Jackson, Mich., to design and build what could be the nation's first plant to convert petroleum liquids to natural gas. The plant will cost $40 million and will have an initial capacity of 100 million s.c.f. per day of synthetic natural gas when it starts up in 1973. Consumers Power plans to double the capacity by 1974. The plant will be based on the catalytic rich gas (CRG) process researched by British Gas Council and developed by Humphreys & Glasgow International, Ltd. Feedstock for the plant will be natural gas condensate transported via pipeline from Canada. The process can also operate on blended refinery gases, liquefied petroleum gas, naphthas, and propane-butane mixtures. The process produces a gas with a heating value of more than 985 B.t.u. per s.c.f. According to Lummus president William P. Orr, "This process makes available to utilities a demonstrated viable solution to the pressing natural gas shortage." Lummus will also design a coalto-gas pilot plant for the U.S. Bureau of Mines based on BuMines' Synthane process. BuMines plans to build a prototype unit to process 70 tons of coal per day at its research complex at Bruceton, Pa. In the Synthane process, coal is first pretreated, a step which makes possible the use of any type coal, including "caking" varieties. After pretreatment, the coal goes to a gasification chamber where it reacts with oxygen and steam to produce methane, carbon monoxide, and hydrogen. After a cleaning step to remove impurities, the gas is catalytically converted to obtain additional methane from the carbon monoxide and hydrogen. This reaction changes the heating value of the gas from 500 to 900 B.t.u. per cu. ft. A major advantage of the process is high conversion of coal to methane in the gasification chamber.
