Process and system for converting solid carbon-based feedstocks to hydrocarbons and coke utilizing a coke drum

A process, comprising:

• receiving, in a first unheated coke drum, a feedstock comprising a solid carbon-based material in an unheated state;
• after a sufficient amount of the feedstock comprising the solid carbon-based material is received in the first unheated coke drum, heating the first unheated coke drum and the feedstock comprising the solid carbon-based material in the first unheated coke drum to a first temperature to form a first heated coke drum containing a heated feedstock comprising the solid carbon-based material in a semi-solid state or a melted state in a first heated coke drum;
• and
• flowing a heated petroleum residue-containing feedstock into the first heated coke drum at a second temperature for processing the heated feedstock comprising the solid carbon-based material in the semi-solid state or the melted state under reaction conditions to convert at least a portion of the heated feedstock comprising the solid carbon-based material in the semi-solid state or the melted state to a product stream comprising a gas phase comprising hydrocarbons and hydrogen, and coke.