Liquefaction behavior of a Canadian subbituminous coal in comparison to that of several US lignites and subbituminous coals

Alberta Highvale subbituminous coal has been used in three single-pass tests in the continuous process unit at GFETC. The three tests were Highvale subbituminous comprise at best, a scouting of the coals' reactivity. The Highvale coal appears less reactive than North Dakota or Texas lignites to the liquefaction conditions employed and its response is somewhat similar to that observed for Wyodak coal. Highvale coal was also found to react better with hydrogen than with syngas. Net SRL + oil yields using hydrogen were about 43 wt % as compared to 28 wt % using syngas. Overall maf coal conversions with Highvale were low with the best reported being about 64 wt %. The single-pass liquids produced by processing Highvale subbituminous coal resemble liquids produced by the same process with Wyodak subbituminous coal. The light oil is more aromatic and contains more phenolic and less H..beta.. protons (potential H-Donors) than light oils from North Dakota or Texas lignites. In comparison, the Alberta coal yielded an SRL of lower quality than a North Dakota lignite (B3), a Texas lignite (BB1) and a Wyoming subbituminous coal (WYO1). The lower SRL recoveries after distillation suggest unstable products were produced during processing. The combination ofmore » conversion, SRL yields and NMR and GPC data indicate that the original Alberta Highvale coal had a fairly high molecular weight basic structure which was cracked best by hydrogen to yield a relatively unstable SRL. This makes it more similar to the Wyodak coal rather than lignites which contain more reactive groups (such as carboxylates) and which react well with CO and water to give relatively stable SRL at proper conditions.« less