The invention is directed to a continuous process to treat a hydrogen sulphide comprising gas comprising the following steps: (a) contacting the hydrogen sulphide comprising gas with an aqueous alkaline solution further comprising sulphide oxidising bacteria thereby obtaining a loaded aqueous solution comprising sulphide compounds and sulphide oxidising bacteria. (b) contacting the loaded aqueous solution with an oxygen comprising gas to regenerate the sulphide oxidising bacteria to obtain a liquid effluent comprising regenerated sulphide oxidising bacteria which is partly used as the aqueous alkaline solution in step (a). (c) separating elemental sulphur as prepared by the sulphide oxidising bacteria in steps (a) and (b) from the loaded aqueous solution of step (a) and/or from the liquid effluent of step (b) and wherein the consumption of oxygen in step (b) is measured and wherein the supply of oxygen in step (b) is controlled by the measured consumption of oxygen.

The invention is directed to a control method for a process to convert bisulphide to elemental sulphur in an aqueous solution comprising sulphide-oxidising bacteria wherein the process is controlled by applying a potential between the anode electrode and the cathode electrode or between the anode electrode and the reference electrode of an electrochemical cell resulting in a current between the cathode electrode and the anode electrode, measuring a current as measured by an electrochemical cell and adapting the process in response to the measured current. The process to convert bisulphide may comprise the following steps: (a) contacting bisulphide with oxidised sulphide-oxidising bacteria in the aqueous solution and elemental sulphur, (b) oxidizing the reduced sulphide-oxidising bacteria, (c) using the oxidised sulphide-oxidising bacteria obtained in step (b) in step (a) and (d) isolating elemental sulphur from the aqueous solution obtained in step (a) and/or step (b).

The invention is directed to a control method for a process to convert bisulphide to elemental sulphur in an aqueous solution comprising sulphide-oxidising bacteria wherein the process is controlled by applying a potential between the anode electrode and the cathode electrode or between the anode electrode and the reference electrode of an electrochemical cell resulting in a current between the cathode electrode and the anode electrode, measuring a current as measured by an electrochemical cell and adapting the process in response to the measured current. The process to convert bisulphide may comprise the following steps: (a) contacting bisulphide with oxidised sulphide-oxidising bacteria in the aqueous solution and elemental sulphur, (b) oxidizing the reduced sulphide-oxidising bacteria, (c) using the oxidised sulphide-oxidising bacteria obtained in step (b) in step (a) and (d) isolating elemental sulphur from the aqueous solution obtained in step (a) and/or step (b).

A method for recovering sulfur within a gas processing system is described herein. The method includes contacting a natural gas stream including an acid gas with a solvent stream within a co-current contacting system to produce a sweetened natural gas stream and a rich solvent stream including an absorbed acid gas. The method also includes removing the absorbed acid gas from the rich solvent stream within a regenerator to produce a concentrated acid gas stream and a lean solvent stream. The method further includes recovering elemental sulfur from hydrogen sulfide (H.sub.2S) within the concentrated acid gas stream via a sulfur recovery unit.

A method for recovering sulfur within a gas processing system is described herein. The method includes contacting a natural gas stream including an acid gas with a solvent stream within a co-current contacting system to produce a sweetened natural gas stream and a rich solvent stream including an absorbed acid gas. The method also includes removing the absorbed acid gas from the rich solvent stream within a regenerator to produce a concentrated acid gas stream and a lean solvent stream. The method further includes recovering elemental sulfur from hydrogen sulfide (H.sub.2S) within the concentrated acid gas stream via a sulfur recovery unit.

A vertically oriented sulfur condenser may employ a plurality of condenser tubes arranged longitudinally within an exterior casing, a liquid sulfur reservoir at a longitudinal end of the sulfur condenser, and a condenser tube wall of at least one of the plurality of condenser tubes that protrudes into and below a liquid sulfur reservoir. A catalyst may be located within the liquid sulfur reservoir. A liquid sulfur outlet may be located at the liquid sulfur surface. A Claus process gas inlet may be proximate a first end of the plurality of condenser tubes. A first tube sheet may connect to and seal an end of the plurality of condenser tubes proximate a first end of the plurality of condenser tubes. A second tube sheet may connect to and seals with the plurality of condenser tubes and the exterior casing proximate a second end of the plurality of condenser tubes.

A vertically oriented sulfur condenser may employ a plurality of condenser tubes arranged longitudinally within an exterior casing, a liquid sulfur reservoir at a longitudinal end of the sulfur condenser, and a condenser tube wall of at least one of the plurality of condenser tubes that protrudes into and below a liquid sulfur reservoir. A catalyst may be located within the liquid sulfur reservoir. A liquid sulfur outlet may be located at the liquid sulfur surface. A Claus process gas inlet may be proximate a first end of the plurality of condenser tubes. A first tube sheet may connect to and seal an end of the plurality of condenser tubes proximate a first end of the plurality of condenser tubes. A second tube sheet may connect to and seals with the plurality of condenser tubes and the exterior casing proximate a second end of the plurality of condenser tubes.

A process and method for removing hydrogen sulfide from a gas and regenerating ferric ions consumed in the hydrogen sulfide scrubbing process at low pH. A two-scrubber regenerative chemical scrubbing system for removing hydrogen sulfide from a gas that provides an economical system for removing hydrogen sulfide from a gas at low pH without the need for chelating agents. An oxide of manganese is used as a catalyst to enhance the regeneration of ferric ions in an aqueous solution under acidic conditions in the presence of oxygen. The process may further include contacting the aqueous solution with a second gas comprising air to replenish the dissolved oxygen in the aqueous solution. The regenerated solution comprising ferric ions can be reused to treat additional hydrogen sulfide containing gases.

A process and method for removing hydrogen sulfide from a gas and regenerating ferric ions consumed in the hydrogen sulfide scrubbing process at low pH. A two-scrubber regenerative chemical scrubbing system for removing hydrogen sulfide from a gas that provides an economical system for removing hydrogen sulfide from a gas at low pH without the need for chelating agents. An oxide of manganese is used as a catalyst to enhance the regeneration of ferric ions in an aqueous solution under acidic conditions in the presence of oxygen. The process may further include contacting the aqueous solution with a second gas comprising air to replenish the dissolved oxygen in the aqueous solution. The regenerated solution comprising ferric ions can be reused to treat additional hydrogen sulfide containing gases.

The invention is directed to a process to prepare elemental sulphur by (i) contacting an aqueous solution comprising bisulphide with oxidised sulphide-oxidising bacteria under anaerobic conditions wherein elemental sulphur is produced and a reduced sulphide-oxidising bacteria is obtained and (ii) wherein the reduced sulphide-oxidising bacteria are oxidised by transfer of electrons to an anode of an electrochemical cell to obtain the oxidised sulphide-oxidising bacteria.