Co-production of hydrogen and sulfuric acid by partial oxidation of sulfur

A method of producing hydrogen, comprising:

• converting sulfur vapor and oxygen gas in a first zone of furnace into sulfur monoxide;
• injecting water into a second zone of the furnace;
• converting the sulfur monoxide and the water in the second zone into hydrogen gas and sulfur dioxide;
• discharging furnace exhaust gas from the furnace, the furnace exhaust gas comprising unreacted sulfur vapor, the hydrogen gas and the sulfur dioxide;
• condensing the unreacted sulfur vapor in the furnace exhaust gas into liquid sulfur in a condenser downstream of the furnace, the condenser comprising a heat exchanger;
• discharging the liquid sulfur from the condenser to a vessel;
• discharging a process gas from the condenser to a quench tower, the process gas comprising the hydrogen gas and the sulfur dioxide;
• absorbing the sulfur dioxide from the process gas into sulfurous acid in the quench tower;
• and
• discharging from the quench tower the hydrogen gas from the process gas, wherein converting sulfur vapor and oxygen gas in the first zone into sulfur monoxide comprises partial combustion of the sulfur vapor, wherein converting the sulfur monoxide and water in the second zone into hydrogen gas and sulfur dioxide comprises a water-gas shift reaction of the sulfur monoxide, and wherein operating temperature of the first zone or the second zone, or both, is in the range of 802° C. to 1608° C.