A depressurization system in fluid communication with a high pressure, high temperature fine solid particles stream having entrained gas therein, the system comprising: a means for cooling the high pressure, high temperature fine solid particles stream having entrained gas therein resulting in a high pressure, lower temperature cooled fine solid particles stream having entrained gas therein; a separator for separating the cooled fine solid particles from at least a portion of the high pressure, lower temperature fine solid particles stream having entrained gas therein, the separator comprising: a housing defining an interior separator cavity and having a housing wall; a filter disposed within the interior separator cavity and having an inner wall and a spaced outer wall, the outer wall being spaced from the housing wall and defining an enclosed annulus between the filter and the housing wall, wherein the inner wall defines a conduit in fluid communication with the high pressure, lower temperature cooled fine solid particles stream having entrained gas therein, the inner wall comprising a first plurality of pores having a first pore diameter that is greater than a mean diameter of the fine solid particles, wherein the outer wall comprises a second plurality of pores having a second pore diameter that is less than the mean diameter of the fine solid particles, wherein the inner wall and the outer wall of the filter define an enclosed filtration cavity; a bed of granules disposed in the filtration cavity; and a gas outlet in selective fluid communication with the annulus for egress of the pressurized gas; wherein at least a portion of the cooled fine solid particles exit the separator via a solids outlet positioned adjacent a distal end of the conduit. a means for cooling the high pressure, high temperature fine solid particles stream having entrained gas therein resulting in a high pressure, lower temperature cooled fine solid particles stream having entrained gas therein; a separator for separating the cooled fine solid particles from at least a portion of the high pressure, lower temperature fine solid particles stream having entrained gas therein, the separator comprising: a housing defining an interior separator cavity and having a housing wall; a filter disposed within the interior separator cavity and having an inner wall and a spaced outer wall, the outer wall being spaced from the housing wall and defining an enclosed annulus between the filter and the housing wall, wherein the inner wall defines a conduit in fluid communication with the high pressure, lower temperature cooled fine solid particles stream having entrained gas therein, the inner wall comprising a first plurality of pores having a first pore diameter that is greater than a mean diameter of the fine solid particles, wherein the outer wall comprises a second plurality of pores having a second pore diameter that is less than the mean diameter of the fine solid particles, wherein the inner wall and the outer wall of the filter define an enclosed filtration cavity; a bed of granules disposed in the filtration cavity; and a gas outlet in selective fluid communication with the annulus for egress of the pressurized gas; a housing defining an interior separator cavity and having a housing wall; a filter disposed within the interior separator cavity and having an inner wall and a spaced outer wall, the outer wall being spaced from the housing wall and defining an enclosed annulus between the filter and the housing wall, wherein the inner wall defines a conduit in fluid communication with the high pressure, lower temperature cooled fine solid particles stream having entrained gas therein, the inner wall comprising a first plurality of pores having a first pore diameter that is greater than a mean diameter of the fine solid particles, wherein the outer wall comprises a second plurality of pores having a second pore diameter that is less than the mean diameter of the fine solid particles, wherein the inner wall and the outer wall of the filter define an enclosed filtration cavity; a bed of granules disposed in the filtration cavity; and a gas outlet in selective fluid communication with the annulus for egress of the pressurized gas; wherein at least a portion of the cooled fine solid particles exit the separator via a solids outlet positioned adjacent a distal end of the conduit.