the unit was repaired and acetic acid production resumed. Meanwhile, during the week of Oct. 7, technical problems also forced Hoechst to shut down its 440 million-lb-per-year 2-ethylhexanol plant in Oberhausen, Germany. During a routine technical inspection of the plant, a minor fire in a small stand-by unit caused the shutdown. The plant was restarted on Oct. 15. In addition, on Oct. 1, Celanese Canada and Hoechst Celanese Chemical Groupboth part of Hoechst Global Basic Chemicals—declared force majeure on shipments from Canada of methanol and two derivatives, formaldehyde and pentaerythritol. Hoechst's Edmonton methanol facility in Alberta was shut down when problems arose in trying to restart the unit after scheduled maintenance. On Oct. 10, the 1.87 billion-lb-per-year methanol unit returned to operation and the company lifted force majeure. The impact of these and other outages on Hoechst's bottom line has yet to be seen. As the company deals with financial and other possible repercussions, its ability to carry out programs to increase plant safety and avoid manufacturing disruptions will be watched industrywide for signs of success. Ann Thayer
Mexico clings to petrochemical assets Responding to political and public pressure, the Mexican government abandoned its already delayed plans to sell a majority stake in government-owned petrochemical assets to domestic and foreign investors. But the government's goal remains to expand and modernize both the oil and petrochemical industries. The petrochemical assets of Petroleos Mexicanos (Pemex) contained in 61 plants at 10 complexes will be grouped into newly created Pemex subsidiaries by Jan. 1, 1997. The government will retain ownership of a 51% share in the Pemex subsidiaries, which will have complete management control of the petrochemical facilities. Up to a 49% share in each subsidiary will then be offered next year to domestic and foreign investors. However, investors can also wait for construction of completely new plants— that have been or could be proposed—in which they can take a 51 to 100% stake. Only plants for petrochemicals—such as ethylene, propylene, benzene, and
Pemex's San Martin Texmelucan complex, which makes acrylonitrile and methanol, is one of 10 petrochemical facilities being offered for investment.
other downstream products—will be available to investors. Facilities that produce petrochemical feedstocks, including ethane and butane, will remain entirely owned by Pemex. And an additional feedstock—methane derived from Pemex operations—has been added to this category. In late September, a subsecretary in Mexico's Secretariat of Energy told C&EN that the Mexican government "learned that privatization was not as clear-cut an option as initially expected" (C&EN, Oct. 7, page 19). He also said the legality of privatization was being studied by the Ministry of the Comptroller. Various labor unions, political parties, and the public protested any sale of oil and oil-related enterprises as a violation of Mexico's Constitution, a selling off of part of the nation's sovereignty. The original privatization plan would have let Mexican and foreign companies acquire at least 51% ownership of individual plants within the 10 complexes (C&EN, Jan. 8, page 10). The Mexican government was to hold a one-fifth to one-third share, but over two to five years it could sell its holding or a portion of it to the majority owners. Mexico's chemicals manufacturing association, Asociacion Nacional de la Industria Quimica (ANIQ), generally approves of the government's actions: "[Because of] the inevitable need [to strengthen] the competitiveness of the Mexican petrochemical industry, ANIQ sees as positive the announcements made by the energy secretary.'' ANIQ also says the government's decision to set out "a regulatory framework [that is] clear and certain" will lead to better opportunities for long-term
investments in the petrochemical industry. Terra Industries says it is willing to listen to the new proposals by the Mexican government and then determine whether it will seek to invest. Earlier this year, Sioux City, Iowa-based Terra, along with Kansas City, Mo.based Farmland Industries, entered the bidding for five ammonia plants at Pemex's Cosoleacaque complex in the Veracruz region of Mexico. George Peaff
Trace compounds in oil may aid search for new petroleum reserves The search for new economically viable petroleum reserves may be helped in the future by research that links the concentrations of trace compounds in crude oils to oil migration distances. An international team of researchers from Britain, Canada, China, Malta, Norway, and the Netherlands has shown that changes in the absolute and relative concentrations of two nonalkylated benzocarbazole isomers—which are present in trace amounts in oils—correlate with the distances traveled by an oil between the source rock that generated and expelled the oil and the oil reservoir [Nature, 383,593(1996)]. Stephen R. Larter, professor of geology at the University of Newcastle, England, and coworkers compared the concentrations of benzol]carbazole and benzo[c] carbazole with migration distances for samples of reservoired oils in five different petroleum systems, two in Western Canada and three in the North Sea. A petroleum system is a threedimensional section of Earth's subsurface consisting of source rock, a migration pathway through a carrier bed, and an oil reservoir with a seal. OCTOBER 21, 1996 C&EN 11
