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Total Pages : 6 pages
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Book Synopsis Fundamental Studies of Coal Liquefaction. Quarterly Report No. 9, October 1, 1993--January 1, 1994 by :
Download or read book Fundamental Studies of Coal Liquefaction. Quarterly Report No. 9, October 1, 1993--January 1, 1994 written by and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results obtained over the past period include studies in our cell with Wyodak coal, and argon, water, n-undecane, and tetralin as media. The argon work was conducted at 7 atm and the others at 200 atm, and the results are shown in Figure 1. As we saw with Illinois No. 6 coal, in argon the particles began to swell at around 300°C, and develop a fluid-like appearance. As just noted, the phenomenon appears to be the development of a tar, which is slowly expelled from the particles with increasing temperature. The overall thermal behavior was essentially the same for the three particles, but the extent of the tar development was different within them, apparently reflecting different levels of tar precursors in the individual particles. Again or as or Illinois No. 6, there was an abrupt evaporation of the tar at around 350°C. The residue was a collection of particles very similar in size and shape to the starting particles. The behavior in water was also like that seen for the Illinois coal. The coal began to shrink at around 300°C, or at the same point at which the tar evolution began in argon. The shrinking continued to around 350°C, at which point there was a curious, momentary swelling. This action continued only briefly and the particles then resumed shrinking up to the highest temperature attained. The undecane result was also like that seen for the Illinois coal. Thus in marked contrast to the argon and water results, there was no change in size nor shape of the coal particles. Finally, Figure 1 also shows data with tetralin as medium, and the results display yet another type of behavior. In this case, much like the results for undecane, there is no change in the particles to about 425°C. At that point they begin to shrink very rapidly, consistent with the temperature range at which coal conversion becomes active in tetralin (Gorin, 1981).