Department of Chemical Engineering, West Virginia University, PO Box 6102, Morgantown, WV 26506-6102, USA
Abstract
The liquefaction of Blind Canyon seam coal in the presence of one of four different types of co-liquefaction agents (CLAs) was studied at 350°C and 1000 psi (cold) hydrogen pressure. The role of tetralin as a solvent was studied. The four CLAs used include sawdust, horse manure, cow manure and commercial “Super Manure”. The conversion and the asphaltene-plus-preasphaltene yield were obtained by successive dissolution in tetrahydrofuran and hexane, respectively, with the oil-plus-gas yield obtained by difference. Results (on a dry, ash-free basis) are reported as both the overall values of conversion and yields, as well as the incremental differences in conversion and yields, relative to separate liquefaction of coal and the CLA. With or without the addition of tetralin, the overall conversion with cow manure is the smallest for the four co-liquefactions. In the absence of tetralin, the asphaltene-plus-preasphaltene yields are all similar. The presence of tetralin increases the overall conversions and the asphaltene-plus-preasphaltene yields. A study of the incremental differences in conversions and yields indicates that the four CLAs interact with coal and tetralin in different ways. The incremental conversion and the asphaltene-plus-preasphaltene yield appear to be related to the amount of hemi-cellulose in the CLAs, while the incremental oil-plus-gas yield appears to be related to the amount of lignin. Added inorganic compounds appear to negate incremental improvements in the oil-plus-gas yield when tetralin is present."
"Tetralin" - the word is a contraction of the compound's full name - is cited frequently in the literature as an agent that can promote the direct liquefaction, the dissolution, of coal, and apparently some organic matter, as well. This is an example, we believe, of "direct" coal liquefaction, as opposed to "indirect" liquefaction wherein syngas is first generated from coal via controlled thermal decomposition, and then is condensed back into liquid through the mediation of a suitable catalyst.
Make note of the "agricultural wastes" that can be included in the feed. They include sawdust and manure, confirming our previous, documented, assertions that both cellulose and, by inference, sewage sludge, can be included in the feed stock of suitably-designed coal-to-liquid conversion facilities.
And, again, West Virginia University is demonstrating it's leadership in developing these alternative, liquid fuel technologies, using our abundant coal resources coupled with renewable agricultural products that can compensate for emissions of carbon, and provide a sustainable source of raw material.