I was wundering about that Hog Fuel myself so I did some poking around online:
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Hog Fuel
Biomass fuel that has been prepared by processing through a "hog" - a mechanical shredder or grinder. If produced by primary forest industries, it usually consists of a mixture of bark and wood often with sawdust, shavings or sludge mixed in and is generally wet and fibrous with a high ash content. Also produced from secondary materials such as pallets, construction or demolition wood yielding a dry, mostly wood fuel but often with significant contaminant inorganics.
http://www.canren.gc.ca/prod_serv/index.asp ----
A specific grade of ground up wood and bark. It varies in size but is generally between ½” and 6” screen size. In the Pacific Northwest, hog fuel from CDL recycling facilities is generally used to fuel boilers for the wood and paper processing or other industries.
http://www.metrokc.gov/dnrp/swd/construction-recycling/cdl-definitions.asp
