Capacity grows for olefins worldwide With growing demand for ethylene and its coproducts and derivatives, announcements of expansions continue in the olefins segment of the chemical industry. The largest expansion announced this month is by Dow Chemical, which plans a new cracker at its Freeport, Tex., plant site with an ethylene capacity of 1.5 billion lb per year. Coproducts capacity will be 600 million lb per year of propylene, other olefins, and aromatics, including 80 million gal of benzene a year. Dow anticipates startup in early 1992 for the cracker. Feedstocks will range from ethane to naphtha. Two new propylene facilities are being planned. Enterprise Products Co. has begun a joint venture with Aristech Chemical, Fina Oil & Chemical, and Quest Energy to build a unit at Mont Belvieu, Tex., capable of making 720 million lb per year of polymer-grade propylene through fractionation and purification of various propylene-rich feedstocks. The Enterprise unit can be expanded to more than 1 billion lb, says Charles J. Roth, executive vice president. Enterprise currently runs a 680 million lb-per-year propylene unit at the site. Intercontinental Terminals will build and operate, at its Houston Ship Channel terminal, a 10,000 metric-ton-per-year refrigerated storage facility to be under long-term lease to Himont. The Himont storage unit will be the second that Intercontinental Terminals will build for use in export and import of propylene, says Intercontinental Terminals president Stephen W. Miles. Polyolefin expansions include units for both high-density polyethylene and polypropylene. Phillips 66 Co. will expand its Pasadena, Tex., HDPE unit by 275 million lb per year to about 1.8 billion lb per year by early 1990. In the U.K., Shell Chemical U.K. will build a new polypropylene unit at Carrington with capacity for 287 million lb per year. When completed in 1991, the unit will replace an old 265 million lb-per-year unit.
Benzene snapshot captures images of individual rings The distinctive six-membered-ring shape of benzene is clearly visible in pictures of the molecule generated with a scanning tunneling microscope (STM) by IBM scientists. The images look remarkably like the space-filling molecular models of benzene that chemists have used for decades. The technique, invented at IBM's research labs in Zurich in 1981, employso a needlelike probe that scans the sample surface at a distance of about 10 A. A current passes between the probe and sample when a voltage is applied to the probe. The size of the current, which varies with the gap between the two surfaces, is a sensitive indicator of the distance between them. Scientists at IBM's Almaden Research Center in San Jose, Calif., studied an ordered array of benzene and carbon monoxide molecules tightly bonded to a rhodium surface. (The carbon monoxide does not show up in the picture.) The researchers first tried to work with benzene alone, but found the molecules tended to slither across the rhodium surface, blurring the STM image.
Industry executives are aware of the potential for sizable overcapacity (and marginal profits) for basic organic chemicals and their derivatives by the early 1990s. Some industry sources have suggested that many of the capacity expansion plans revealed since early this spring could be preemptive announce-
ments, aimed at making other producers r e t h i n k their expansion plans. Large reductions in company market research staffs during recent years, one industry source says, could mean there possibly are errors in estimates of future demand for chemicals and polymers. Bruce Greek
U.K. slashes breeder reactor program In a major policy decision taken by the British government, work on fast breeder reactor technology in the U.K. is to be cut back during the next five years. One outcome of the move is that the work force of the U.K. Atomic Energy Authority will be reduced drastically. In making the announcement, Cecil E. Parkinson, U.K. Secretary of State for Energy, notes that his decision is based on "the expectation that commercial deployment of fast reactors in the U.K. will not be required for 30 or 40 years." Continu-
ing the program at the present level doesn't warrant the high costs involved, he reasons. Ironically, British scientists were among the early proponents of the fast breeder reactor 40 or so years ago. The term takes its name from the high speed of the neutrons in the reactor core, which leads to more efficient use of fuel. Indeed, a feature of such reactors is that plutonium, itself a fuel, is bred when the fast neutrons collide with uranium238 nuclei. So by progressively generating and burning plutonium, a August 1, 1988 C&EN
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