Improving the Environmental and Economic Viability of U.S. Oil Shale via Waste-to-Byproduct Conversion of Semicoke to Sorbents

Abstract

This investigation demonstrates the feasibility of mitigating the economic and environmental burdens associated with commercialization of oil shale by converting its primary solid waste, semicoke, to an adsorbent material. U.S. White River Mine oil shale was pyrolyzed at 600 °C to produce a semicoke; its activation energy of pyrolysis was calculated using the distributed activation energy model to be 206.9 kJ/mol, similar to other domestic oil shales. This simulated semicoke was chemically activated using HCl, KOH, and a double-activation procedure of either HCl followed by KOH or vice versa. The acid-activation step was considerably more effective in developing the surface area and porous network of the semicoke sorbents, as well as removing carbonate minerals, than KOH. The activation energies of oxidation of the raw, pyrolyzed, and activated samples ranged from 100.5 kJ/mol (raw) to 189.0 kJ/mol (semicoke), with the activated samples between these values. Of the activated samples, HCl + KOH had the low...