Field processing natural gas for sulfur recovery with dynamically adjustable flow rate control

An apparatus for desulfurization of a continuously flowing sour gas stream in which a sulfur concentration varies over time, comprising:

• a fixed-sized continuous conversion pressure vessel;
• a flow control valve that controls a rate of flow of a sour gas stream into the pressure vessel;
• a sensor that continuously measures the sulfur concentration in the sour gas stream;
• a reagent tank;
• an oxidizer tank;
• a phase separator that separates sweet gas as a gaseous phase after hydrogen sulfide in a sour gas stream in the pressure vessel is converted to elemental sulfur, sulfur species, or both by contact with reagent from the reagent tank and oxidizer from the oxidizer tank;
• and
• a PLC (programmable logic controller) that:
• continuously provides updated flow rates based on the sulfur concentration measurements from the sensor to achieve maximum sweet gas production with continuous flow of the sour gas stream into the continuous conversion pressure vessel with adequate contact time with a reagent introduced from the reagent tank and oxidizer introduced from the oxidizer tank in the continuous conversion pressure vessel to produce a sweet gas stream from the sour gas stream;
• and
• dynamically adjusts rate of flow of the sour gas stream into the pressure vessel based on the updated flow rates by sending control signals to the flow control valve, the flow control valve being responsive to the control signals to adjust the rate of flow of the sour gas stream into the pressure vessel.