Status of the Development of EDS Coal Liquefaction

This article traces the evolution and development of a modern coal liquefaction technology, the EDS (Exxon Donor Solvent) process, over a period of 15 years. During this time the technology has been advanced from laboratory experiments to a pilot plant with a coal feed rate of 250 tons per day, and findings from several areas of science and technology have been important. The process is now in the final stage of development to generate the data needed to design a plant of commercial size.     

Primary sulfates in atmospheric sulfates: estimation by oxygen isotope ratio measurements

The relative amounts of primary and secondary sulfates in atmospheric aerosols and precipitation can be estimated from measurements of the stable oxygen isotope ratios. The oxygen-18 content of sulfates formed in power plant stack gases before emission into the atmosphere is significantly higher than that of sulfates formed from sulfur dioxide after emission. Results show that 20 to 30 percent of the sulfates in rain and snow at Argonne, Illinois, are of primary origin.