Multi stage sulfur removal system and process for an auxiliary fuel system

A process for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the process comprising:

• isolating a first vapor permeate stream and a first retentate stream from a primary fuel stream by passing a portion of the primary fuel stream through a first membrane separation stage;
• condensing a portion of the first vapor permeate stream in a first separation stage partial condenser into a first liquid stage stream and a first vapor stage stream;
• passing the first vapor stage stream through a desulfurization reactor;
• condensing a portion of the first vapor stage stream in a second first stage partial condenser into a second liquid stage stream;
• isolating a second vapor permeate stream and a second retentate stream from the second liquid stage stream by passing the second liquid stage stream through a second separation stage;
• and
• mixing the first retentate stream and the second vapor permeate stream and returning the mixture to the primary fuel stream.

A process for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the process comprising:

• isolating a first vapor permeate stream and a first retentate stream from a primary fuel stream by passing a portion of the primary fuel stream through a first membrane separation stage;
• condensing a portion of the first vapor permeate stream in a first separation stage partial condenser into a first liquid stage stream and a first vapor stage stream;
• passing the first vapor stage stream through a desulfurization reactor;
• condensing a portion of the first vapor stage stream in a second first stage partial condenser into a second liquid stage stream;
• and
• isolating a second vapor permeate stream and a second stage retentate stream from the second liquid stage stream by passing the second liquid stage stream through a second separation stage.

A system for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the system comprising:

• a first separation stage to separate a portion of a primary fuel stream into a first vapor permeate stream and a first retentate stream;
• a first separation stage partial condenser connected to the first vapor permeate stream condensing a portion of the first vapor permeate stream into a first liquid stage stream and a first vapor stage stream;
• a second separation stage partial condenser condensing a portion of the first vapor stage stream into a second liquid stage;
• a second separation stage for separating the second liquid stage stream into a second vapor permeate stream and a second retentate stream;
• and
• a mixer to mix the first retentate stream and the second vapor permeate stream and returning the mixture to the primary fuel stream.

A system for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the system comprising:

• a first separation stage to separate a portion of a primary fuel stream into a first vapor permeate stream and a first retentate stream;
• a first separation stage partial condenser connected to the first vapor permeate stream condensing a portion of the first vapor permeate stream into a first liquid stage stream and a first vapor stage stream;
• a second separation stage partial condenser condensing a portion of the first vapor stage stream into a second liquid stage;
• and
• a second separation stage for separating the second liquid stage stream into a second vapor permeate stream and a second retentate stream.

A system for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the system comprising:

• a first separation stage to separate a portion of a primary fuel stream into a first vapor permeate stream and a first retentate stream;
• a first separation stage partial condenser connected to the first vapor permeate stream condensing a portion of the first vapor permeate stream into a first liquid stage stream and a first vapor stage stream;
• a second separation stage partial condenser condensing a portion of the first vapor stage stream into a second liquid stage;
• and
• a polishing filter, connected between the first separation stage and the first separation stage partial condenser receiving the first stage permeate vapor, that contains a catalyst to convert the sulfur compounds to hydrogen sulfide or sulfur oxides to increase the selectivity and absorption capacity of the polishing filter.

A process for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the process comprising:

• isolating a first vapor permeate stream and a first retentate stream from a primary fuel stream by passing a portion of the primary fuel stream through a first membrane separation stage;
• condensing a portion of the first vapor permeate stream in a first separation stage partial condenser into a first liquid stage stream and a first vapor stage stream;
• reacting the vapor stage stream with a reactant in a catalyst reactor to form isolatable sulfur compounds;
• isolating the sulfur compounds in a secondary isolation component;
• condensing a portion of the first vapor stage stream in a second first stage partial condenser into a second liquid stage stream;
• and
• isolating a second vapor permeate stream and a second retentate stream from the second liquid stage stream by passing the second liquid stage stream through a second separation stage.

A system for producing an auxiliary fuel stream containing a low concentration of sulfur compounds from a primary fuel stream, the system comprising:

• a first separation stage to separate a portion of a primary fuel stream into a first vapor permeate stream and a first retentate stream;
• a first separation stage partial condenser connected to the first vapor permeate stream condensing a portion of the first vapor permeate stream into a first liquid stage stream and a first vapor stage stream;
• a reactive desulfurization catalyst reactor receiving the first vapor stage stream;
• and
• a second separation stage partial condenser condensing a portion of the first vapor stage stream from the catalyst reactor into a second liquid stage.