Method of purifying hydrocarbons and regeneration of adsorbents used therein

A method for removing contaminants from a hydrocarbon stream comprising:

• passing a hydrocarbon stream comprising contaminants through a first adsorption bed containing a desiccant material;
• passing an effluent from the first adsorption bed into a second adsorption bed containing molecular sieves to adsorb at least a portion of the contaminants onto the molecular sieves;
• passing an effluent from the second adsorption bed into a third adsorption bed containing desiccant material;
• and
• regenerating the molecular sieves by purging at least said second and third beds, or at least said first and second beds, with a regeneration fluid stream comprising water to desorb and remove at least a portion of the contaminants adsorbed on said molecular sieves, said regeneration fluid stream comprising water contacting either said first adsorption bed containing desiccant material or said third adsorption bed containing desiccant material prior to contacting said second adsorption bed containing molecular sieves.

A method for removing contaminants from a hydrocarbon stream comprising:

• passing a hydrocarbon stream comprising contaminants through a first adsorption bed containing molecular sieves to adsorb at least a portion of the contaminants onto the molecular sieves;
• passing an effluent from the first adsorption bed into a second adsorption bed containing a desiccant material;
• and
• regenerating the molecular sieves by purging said first and second beds with a regeneration fluid stream comprising water to desorb and remove at least a portion of the contaminants adsorbed on said molecular sieves, said regeneration fluid stream comprising water contacting said second adsorption bed containing desiccant material prior to contacting said first adsorption bed containing molecular sieves.

A method of regenerating molecular sieves, comprising:

• placing said molecular sieves in fluid communication with a bed containing a desiccant material;
• contacting said desiccant material with a regeneration fluid stream comprising water to adsorb at least a portion of said water onto said desiccant material to form an at least partially dried regeneration fluid stream in contact with an at least partially hydrated desiccant material;
• heating said at least partially hydrated desiccant material to a temperature above about 100° C. to release water adsorbed thereon into said at least partially dried regeneration fluid stream;
• and
• passing said at least partially dried regeneration fluid stream through said molecular sieves to desorb and remove at least a portion of contaminants adsorbed thereon.

A method for removing contaminants from natural gas, comprising:

• providing a natural gas stream comprising contaminants;
• passing said natural gas stream comprising contaminants through a first adsorbent bed containing molecular sieves to adsorb at least a portion of said contaminants onto said molecular sieves;
• passing an effluent from said first adsorbent bed through a second adsorbent bed containing a desiccant material;
• passing a first regeneration fluid stream comprising water counter-currently through said first and second adsorbent beds for a first period of time;
• maintaining the temperature of said first regeneration fluid stream in a range of from about 50° C. to about 200° C. during said first period of time;
• passing a second regeneration fluid stream counter-currently through said first and second adsorbent beds for a second period of time, wherein said second regeneration fluid stream comprises water in an amount less than 20 ppmv;
• maintaining the temperature of said second regeneration fluid stream in a range of from about 250° C. to about 400° C. during said second period of time;
• and
• cooling said first and second adsorption beds to a temperature below 250° C.

A method for producing a liquefied natural gas, comprising:

• providing a first adsorbent bed containing molecular sieves, said molecular sieves having methanol adsorbed thereon;
• providing a second adsorbent bed containing a desiccant material;
• passing a first regeneration fluid stream comprising water counter-currently through said first and second adsorbent beds for a first period of time;
• maintaining the temperature of said first regeneration fluid stream in a range of from about 50° C. to about 200° C. during said first period of time;
• passing a second regeneration fluid stream counter-currently through said first and second adsorbent beds for a second period of time, wherein said second regeneration fluid stream comprises water in an amount less than about 20 ppmv;
• maintaining the temperature of said second regeneration fluid stream in a range of from about 250° C. to about 400° C. during said second period of time;
• cooling said first adsorbent bed to a temperature below 250° C. to provide a cooled adsorbent bed containing regenerated molecular sieves;
• providing a natural gas stream comprising methanol;
• passing said natural gas stream comprising methanol through said cooled adsorbent bed containing regenerated molecular sieves to adsorb at least a portion of said methanol onto said regenerated molecular sieves;
• passing an effluent from said cooled adsorbent bed containing regenerated molecular sieves through an adsorbent bed containing a desiccant material;
• recovering said effluent from said adsorbent bed containing a desiccant material;
• and
• cooling said effluent to a temperature sufficient to produce a liquefied natural gas at atmospheric pressure.