Short contact time coal extract

One of the objectives of this work was to determine the effect of higher reactor pressure and space velocity on conversion and product quality. Heretofore, only temperature had been used to adjust or maintain conversion and product quality. Two different coal extract types were used in this study - namely, whole filter feeds obtained from Wilsonville short contact time coal extract (SCT) operations (Wilsonville run numbers 145 and 146 with 287 and 580 pounds of Indiana V coal feed per hour, respectively), and a conventional solvent refined coal (SRC-I)/ Koppers heavy residue creosote oil (KC-Oil) feed blend. The SRC-I was obtained from the Fort Lewis, Washington SRC-I facility... 

Short contact time coal extracts show a greater percentage denitrogenation in the total liquid product than SRC-I coal extract when processed by LC-Fining. Also, short contact time coal extracts show a lower C1-C4 gas yield. 

Non-deashed short contact time coal extracts show a higher 500°F+ and 650°F+ conversion than SRC-I coal extracts at a given 850°F+ conversion in the LC-Finer. Deashed short contact... 

This study describes the results of processing both conventional solvent refined coal extract (SRC-I) and short contact time coal extract. Both coal extracts have been run at several space velocities, temperatures, and total reactor pressures for comparative purposes. The effect of catalyst deactivation has also been considered. The short residence time coal extract was run in both a deashed and non-deashed mode of operation. 

Another parameter is the intrinsic extractability of the parent coals by pyridine. As can be seen in Figure 12, the shape of the curve of pyridine extract yield from the various coals vs. their carbon content follows the same trend as the short contact time conversions of these coals. 

Although Neavel obtained high yields of pyridine-solubles with naphthalene at short contact times for some US bituminous coals (201. conversions were much lower after longer extraction times. This trend is not evident for Linby coal... 

A short contact time SCT) coal extract, as prepared at Wilsonville, is obtained by feeding the coal slurry through only the slurry preheater and transfer lines. The conventional solvent refined coal has a residence time in the slurry preheater, transfer lines, and dissolver. The SCT coal extract is, consequently, reacted at higher temperatures to produce similar yields of SRC-type product at very high flow rates. The SCT coal extract used for the studies reported herein was received as non-deashed material which would have been used as a feedstock for the U.S. Filter or Kerr-McGee Critical Solvent Deashing at Wilsonville. 

That the combination of dilution with hexane and HC1 treating is more effective than dilution with hexane alone for precipitating nitrogen compounds in the product of hydroliquefaction is seen in Experiment 3, from the nitrogen analyses and yields of Schemes B and C extracts in Table VIII. In this experiment under conditions of relatively short contact time, the yield of extract in Scheme B products is close to that of the coal charged, indicating that essentially all of the liquefied coal is asphal-... 

Metals such as Fe, Cu, Zn, Pb, Hg, Se, As, Co, Cd, Cr and Ni have been extracted using an acid solution (usually HNO,) in a focused open-vessel system for periods ranging from 3 min for soil samples [68] to 50 min for coal (where metals are much more strongly retained) [46] the system of Fig. 5.8A allowed the sample to be brought into contact with fresh solvent in four cycles, which resulted in the relatively short extraction time achieved. One clear example of the dramatically reduced extraction times afforded by microwaves is the extraction of Pb, Zn and Cu from calcareous soil [277], where the sequential procedure used proved considerably faster than conventional extraction (2 h versus 20 h). 

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