Hydrogen sulfide removal process

A continuous process for the removal of hydrogen sulfide from a gas stream, which comprises:

• contacting a reaction medium comprising a single non-aqueous Lewis base which is quinoline and having the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all said hydrogen sulfide from said gas stream, notwithstanding variations in the stoichiometric balance between said hydrogen sulfide and said sulfur dioxide in said reaction medium with said gas stream in the presence of sulfur dioxide in the reaction medium to react with the hydrogen sulfide at a temperature above the melting point of sulfur to form liquid sulfur, in accordance with the equation:
• 2H2S+SO2→3S+2H2O
• in a upper region of a reactor;
• accumulating liquid sulfur from said reaction as a layer in a lower region of said reactor below said reaction medium;
• venting a hydrogen sulfide depleted gas stream from said reactor;
• and
• removing liquid sulfur from the layer thereof,
• wherein sulfur dioxide is passed upwardly through said layer of liquid sulfur to remove dissolved components therefrom and then said reaction medium to provide therein said sulfur dioxide for reaction with the hydrogen sulfide.

A continuous process for the removal of hydrogen sulfide from a sour natural gas stream, which comprises:

• contacting a reaction medium comprising a single non-aqueous Lewis base which is quinoline and having the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all said hydrogen sulfide from said gas stream, notwithstanding variations in the stoichiometric balance between said hydrogen sulfide and said sulfur dioxide in said reaction medium with said gas stream in the presence of sulfur dioxide in the reaction medium to react with the hydrogen sulfide at a temperature above the melting point of sulfur to form liquid sulfur, in accordance with the equation:
• 2H2S+SO2→3S+2H2O
• in an upper region of a reactor;
• accumulating liquid sulfur from said reaction as a layer in a lower region of said reactor below said reaction medium;
• venting a sweetened gas stream from said reactor;
• and
• removing liquid sulfur from the layer thereof,
• wherein sulfur dioxide is passed upwardly through said layer of liquid sulfur to remove dissolved components therefrom and then said reaction medium to provide therein said sulfur dioxide for reaction with the hydrogen sulfide wherein said sour gas stream is dispersed in said layer of liquid sulfur and the dispersed gas stream is permitted to pass upwardly through the layer of liquid sulfur and into direct contact with said reaction medium containing sulfur dioxide in a quantity at least sufficient to convert substantially all the hydrogen sulfide in said gas stream to sulfur.

A continuous process for the removal of hydrogen sulfide from a sour natural gas stream, which comprises:

• contacting a reaction medium comprising a single non-aqueous Lewis base which is quinoline and having the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all said hydrogen sulfide from said gas stream, notwithstanding variations in the stoichiometric balance between said hydrogen sulfide and said sulfur dioxide in said reaction medium with said gas stream in the presence of sulfur dioxide in the reaction medium to react with the hydrogen sulfide at a temperature above the melting point of sulfur to form liquid sulfur, in accordance with the equation:
• 2H2S+SO2→3S+2H2O
• in an upper region of a reactor;
• accumulating liquid sulfur from said reaction as a layer in a lower region of said reactor below said reaction medium;
• venting a sweetened gas stream from said reactor;
• and
• removing liquid sulfur from the layer thereof,
• wherein sulfur dioxide is passed upwardly through said layer of liquid sulfur to remove dissolved components therefrom and then said reaction medium to provide therein said sulfur dioxide for reaction with the hydrogen sulfide,
• wherein said sour gas stream first is heated to at least the melting point of sulfur and then passed to said reactor, and wherein said heating of sour gas stream to said temperature is effected, at least in part, by passing the same in heat exchange relationship with said removed sweetened gas stream, which thereby effects said cooling of the removed sweetened gas stream.

A continuous process for the removal of hydrogen sulfide from a sour natural gas stream, which comprises:

• contacting a reaction medium comprising a single non-aqueous Lewis base which is quinoline and having the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all said hydrogen sulfide from said gas stream, notwithstanding variations in the stoichiometric balance between said hydrogen sulfide and said sulfur dioxide in said reaction medium with said gas stream in the presence of sulfur dioxide in the reaction medium to react with the hydrogen sulfide at a temperature above the melting point of sulfur to form liquid sulfur, in accordance with the equation:
• 2H2S+SO2→3S+2H2O
• in an upper region of a reactor;
• accumulating liquid sulfur from said reaction as a layer in a lower region of said reactor below said reaction medium;
• venting a sweetened gas stream from said reactor;
• and
• removing liquid sulfur from the layer thereof,
• wherein sulfur dioxide is passed upwardly through said layer of liquid sulfur to remove dissolved components therefrom and then said reaction medium to provide therein said sulfur dioxide for reaction with the hydrogen sulfide
• wherein the removed sweetened gas stream is cooled to remove condensables therefrom and the resulting cooled sweetened gas stream is recovered as the product of the process.

A method for the removal of hydrogen sulfide from a gas stream, which comprises:

• passing said gas stream into a body of regenerable reaction medium comprising a single non-aqueous Lewis base which is quinoline and having the capacity to absorb sulfur dioxide in sufficient quantity to remove substantially all said hydrogen sulfide from said gas stream, notwithstanding variations in the stoichiometric balance between said hydrogen sulfide and said sulfur dioxide in said reaction medium and containing a reaction product of sulfur dioxide and the non-aqueous Lewis base to absorb the hydrogen sulfide from the gas stream and to react the absorbed hydrogen sulfide with sulfur dioxide from the reaction product in accordance with the equation:
• 2H2S+SO2→3S+2H2O
• to form product sulfur in a reactor;
• venting a hydrogen sulfide depleted gas stream from an upper portion of the reactor above the reaction medium and permitting said product sulfur to settle to a lower portion of the reactor;
• detecting exhaustion of the capacity of the body of reaction medium to absorb and convert hydrogen sulfide to sulfur;
• and
• replacing the body of spent reaction medium with regenerated reaction medium containing the reaction product.