Production of biorenewable calcined coke from pyrolysis bio-oil distillation bottoms

Y. Elkasabi, A.A. Boateng, C.A. Mullen, M.A. Jackson
USDA-ARS,
United States

Keywords: pyrolysis, bio-oil, calcination, coke, carbon anodes

Summary:

Tail-gas reactive pyrolysis (TGRP) of biomass provides an oxygenated hydrocarbon mixture (“bio-oil”) amenable to distillation and/or hydrotreatment into fuel-grade liquid hydrocarbons. To add value through parallel generation of co-products, we present a straightforward conversion of bio-oil distillate bottoms into calcined coke. Vacuum residuum was subjected to devolatilization and calcination, and the calcined product was characterized physically and chemically. The calcined bottoms exhibited equal and/or improved properties compared to calcined petroleum coke. Calcined bottoms properties were comparable in terms of carbon content and electrical conductivity. Depending on biomass feedstock used for bio-oil production, ash and metals content of calcined bottoms were comparable and/or improved. For all samples, sulfur only existed in trace amounts below 500 ppm, thus providing a potentially valuable source of low-sulfur calcined coke for aluminum smelting, steel carburization, and graphitization.