Renewable Biomass-Derived Coke with Texture Suitable for Aluminum Smelting Anodes

Industrial producers of calcined petroleum coke encounter issues pertaining to product quality and environmental ramifications. While previous attempts to produce biorenewable versions of calcined coke address CO2 footprint, sulfur, and metals poisoning, none have demonstrated a sufficient degree of anisotropy, which is critical for performance in aluminum smelting anodes. Using fast pyrolysis of biomass, we produced bio-oils of sufficient quality whereby coke can be formed through distilling off the volatiles. Tail-gas reactive pyrolysis (TGRP) produced bio-oils with low oxygen content, low viscosity, and high polyaromatic content, all of which are critical for alignment of coke precursors. Distillations at controlled rates and temperatures ensured the alignment of polyaromatic domains leading to coke anisotropy. Bio-oils with oxygen content below 16 wt % successfully produced coke with mixtures of isotropic and anisotropic domains. In coprocessing experiments, mixtures of pyrolysis bio-oil and green pet...