Electrochemical reduction of sulfur from sulfur-containing solid carbon-based materials

A process for removing sulfur from a sulfur-containing solid carbon-based material, comprising:

• introducing an aqueous electrolyte solution comprising an effective amount of an electrolyte to an electrochemical cell comprising a cathode side comprising a cathode, an anode side comprising an anode and a membrane disposed between the cathode and the anode;
• introducing a sulfur-containing solid carbon-based material to the anode side of the electrochemical cell;
• subjecting the aqueous electrolyte solution to an effective voltage and current, thereby generating electrolyte ions and hydrogen;
• wherein the electrolyte ions pass through the membrane from one side to the other side of the electrochemical cell to at least partially oxidize at least a portion of sulfur in the sulfur-containing solid carbon-based material, thereby generating oxidized sulfur and a reduced sulfur-containing solid carbon-based material;
• wherein the reduced sulfur-containing solid carbon-based material has a lower sulfur content by wt. % than the sulfur-containing solid carbon-based material.

A process for removing sulfur from a sulfur-containing solid carbon-based material, comprising:

• introducing an aqueous electrolyte solution comprising an effective amount of an electrolyte to an electrochemical cell comprising a cathode side comprising a cathode, an anode side comprising an anode and a membrane disposed between the cathode and the anode;
• introducing a sulfur-containing solid carbon-based material and a first regenerated redox mediator received from the electrochemical cell to a vessel external to the electrochemical cell wherein the first regenerated redox mediator at least partially oxidizes at least a portion of sulfur in the sulfur-containing solid carbon-based material, thereby generating oxidized sulfur, a reduced sulfur-containing solid carbon-based material, and spent redox mediator;
• passing the spent redox mediator to the electrochemical cell;
• and
• subjecting the spent redox mediator to an effective voltage and current to regenerate the spent redox mediator, thereby providing a second regenerated redox mediator;
• wherein the reduced sulfur-containing solid carbon-based material has a lower sulfur content by wt. % than the sulfur-containing solid carbon-based material.