Oil Shale Conversion Technique Differs In a one step process, pyrolysis gas stream is stabilized immediately after it is formed Pyrochem's one-step process for converting kerogen trapped in oil shale (C&EN, July 26, page 35) differs from other conversion techniques that have been proposed. In the process, being evaluated at Battelle Memorial Institute, the gas stream from oil shale pyrolysis is immediately stabilized after it is formed. The technique, invented by Morgan C. Huntington, president of Pyrochem Corp., and patented (U.S. 3,106,521), converts the trapped kerogen to a water-white, low-viscosity liquid. Hydrogénation of the kerogen before pyrolysis and stabilization of the pyrolysis gases keep the more familiar viscous liquid stream from forming, according to Pyrochem's patent. Union Oil's technique for recovering kerogen involves pyrolysis of crushed oil shale in the presence of air. The TOSCO (Oil Shale Coip.) process doesn't use air in the pyrolysis of shale but uses alumina ceramic balls as a means of transferring heat to the oil shale in the pyrolysis step. The U.S. Bureau of Mines' gas combustion retort uses gas products from the retort in the combustion of oil shale. These retorting techniques produce a waxy kerogen liquid that includes oxygen, nitrogen, and sulfur compounds. The kerogen stream, with or without pretreatment to reduce contaminants level, could be processed much as a petroleum crude. Union Oil visualizes a shale oil refinery consisting of three basic s t e p s coking the kerogen, hydrogen treating the coker distillate, and cat cracking or reforming the stream to improve octane rating. Some by-products would be produced in processing through a shale oil refinery of this type. Coke, of undetermined quality, would be produced by the coking process. Sulfur and ammonia would result from hydrogénation. Union has also handled the kerogen as a petroleum crude oil and found the products satisfactory for a range of products from LPG through kerosine. There are no heating oils or fuel oils produced from the kerogen. However, Union is no longer active in field tests on its process, having re-
moved its plant from service. BuMines' unit at Rifle, Colo., is being used by six oil companies in the first phase of a research program on retort design and operation. Colony Development's prototype unit a t Grand Valley, Colo. (C&EN, July 5, page 16), has started test operations. No results are yet available on Sinclair's in situ process currently under field test. Shale Crushed. To evaluate the Pyrochem process, Battelle crushed shale to about 20 to 60 mesh. (Finding the optimum size range of the shale feed is to be included in future studies.) The crushed shale and a hydrogen stream were preheated separately in the absence of air, then flowed concurrently into a pyrolysis zone held at about 300 p.s.i.g. and 900° F. The gas stream from the pyrolysis zone was immediately contacted with a bed of cobalt molybdenum catalyst, and the stabilized stream condensed. Battelle finds that the stream is totally saturated and essentially free of nitrogen and sulfur. Chromatographic analyses suggest that under certain conditions a material similar in boiling range to gasoline could be produced. According to Pyrochem, hydrogenentrained vaporized fragments from shale oil pyrolysis are quickly stabilized by saturating with hydrogen. All of the usual liquid-phase intermolecular reactions are thus prevented, and the primary condensate consists of saturated hydrocarbons which fractionate predominantly into the gasoline boiling range. Hydrogen, introduced at this early stage of processing, Pyrochem says, becomes a thermal diffuser and heat recovery medium. In addition, volatile matter is more easily entrained and partial pressure in the system is reduced by the presence of hydrogen. Of equal importance, hydrogen is a kerogen liquéfier. It noncatalytically occupies active sites formed by the thermal rupture of oxygen, sulfur, and nitrogen bonds in the pyrolysis gases. Hydrogen is a chemical reactant which removes organically combined oxygen, sulfur, and non-
cyclic nitrogen, and which saturates the more reactive olefins, according to Pyrochem's patent. Pyrochem, which sponsors the research at Battelle's Columbus laboratories, plans to continue the batchscale program. Included in its plans are a larger bench-scale unit simulating countercurrent hydrogen-shale contacting to get data for pilot-plant operation. In previous studies of the process using coal in place of shale, a light yellow, low-viscosity liquid was produced. The liquid has a higher aromaticity than does the liquid produced from shale.
Blender Has Removable Double-Cone Units A new blender that combines a single, stationary drive unit with any desired number of interchangeable, doublecone blending units has been patented (U.S. 3,174,728) by Patterson Industries, Inc., of East Liverpool, Ohio. The company designed the unit for uses which require frequent batch changes or where the cone must be repeatedly scrubbed to prevent product contamination. Patterson's R. E. Witherow says that until now many companies have had to buy complete units for each mixing operation. With the new blender, these companies need only purchase additional blending units after initial purchase of the drive unit, thus eliminating the cost of extra drive units. A conventional fork lift truck is used to transport, attach, or remove the double-cone blending unit from the drive. A yoke on the drive fits around the self-standing double cone, which attaches to and aligns with the yoke by slots in its side. Lock bolts secure it to the yoke. According to the company, design of the double-cone unit is such that it produces extremely homogeneous blends. These blends are possible even with particles of dissimilar size and shape because the double-cone design interfolds the material regardless of its flow properties, the company says. This interfolding action is controlled by the designer. He correlates the proper relationship between the shape, size, and speed of the blender and the materials to be blended. The blender is charged through an opening in the upper cone of the douAUG. 2, 1965 C&EN
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