Four bed regenerable filter system

A method of removing at least a first and a second contaminant from a stream of fluid, said method including the steps of:

• providing said stream of fluid;
• directing said stream of fluid through a filtering system having a first filtering unit with first and second regenerable filter beds and a second filtering unit with third and fourth regenerable filters beds, said first and second filtering units being in fluid connection with one another;
• filtering a first contaminant from said stream of fluid in said first filtering unit
• filtering a second contaminant from said stream of fluid in said second filtering unit;
• regenerating one of said first and second filter beds of said first filtering unit;
• and,
• regenerating one of said third and fourth filter beds of said second filtering unit independent of said step of regenerating said one of said first and second filter beds.

A regenerable filter system comprising:

• a first flow path along which a stream of process fluid flows between a process fluid inlet and a process fluid outlet;
• a first filter unit in said first flow path, said first filter unit comprising a first regenerable filter bed having a first adsorbent for removing a first contaminant from said stream of fluid;
• a second filter unit in said first flow path, said second unit being located between said first unit and said outlet of said first flow path, said second unit comprising a second regenerable filter bed having a second adsorbent for removing a second contaminant from said stream of fluid;
• a second flow path along which a stream of regeneration fluid flows between a regeneration fluid inlet and a regeneration fluid outlet;
• a controller for selectively directing said process fluid through said first flow path and said regeneration fluid through said second flow path, wherein a regeneration cycle of said first filter unit is independent of a regeneration cycle of said second filter unit.