Abstract: In a process for the separation of solid carboxylic acid fines from mother liquor that includes such fines, the mother liquor is fed to a settlement drum at above atmospheric pressure. The mother liquor having a lower concentration of carboxylic fines than that fed to the settlement drum is then removed, wherein the mother liquor removal occurs at a point above the point at which the mother liquor containing fines is fed to the settlement drum. In a system for performing the separation process, a settlement drum has an inlet for mother liquor with carboxylic acid fines and an outlet for mother liquor having a lower concentration of carboxylic acid fines content than that of the mother liquor introduced via the inlet. The settlement drum is configured to operate at above atmospheric pressure and the outlet is located at a point in the settlement drum above the inlet.

Abstract: In a process for the separation and drying of crude carboxylic acid crystals from a slurry in a solvent, the slurry is supplied to a filter operating at pressure and at a temperature above the atmospheric boiling point of the solvent. A cake of separated crystals is removed from the filter and passed to a thermal dryer. In a system for the separation and drying of crude carboxylic acid from a slurry in a solvent, a pressure filter device has a slurry inlet and an outlet for a cake of carboxylic acid crystals. The system also has a thermal dryer and means for transporting the cake of carboxylic acid crystals from the pressure filter device to the dryer. The pressure filter device is configured to operate at a pressure and temperature above the atmospheric boiling point of the solvent.

Abstract: In a process/system for the purification of aromatic dicarboxylic acid (ACA), crude ACA solids are slurried with water recycled from at least a filtration step in a feed preparation zone. Flash steam in vapour phase is supplied to the zone from at least one of a crystallisation step, a filtration step, and a drier step. The slurried ACA solids are preheated to form a solution that is then hydrogenated. The ACA is allowed to crystallise and then crystals of pure ACA are filtered out and water is recovered in a single stage filtration process. Recovered water is supplied to the feed preparation zone and the crystals are dried and recovered. The flash steam recovered from the crystallisation step, filtration step and/or drier step is recovered as a vapour phase stream having a pressure from about atmospheric to 5 barg and supplied to the feed preparation zone without phase change.

Abstract: In a process for the separation and drying of crude carboxylic acid crystals from a slurry in a solvent, the slurry is supplied to a filter operating at pressure and at a temperature above the atmospheric boiling point of the solvent. A cake of separated crystals is removed from the filter and passed to a thermal dryer. In a system for the separation and drying of crude carboxylic acid from a slurry in a solvent, a pressure filter device has a slurry inlet and an outlet for a cake of carboxylic acid crystals. The system also has a thermal dryer and means for transporting the cake of carboxylic acid crystals from the pressure filter device to the dryer. The pressure filter device is configured to operate at a pressure and temperature above the atmospheric boiling point of the solvent.

Abstract: In a process for the separation of solid carboxylic acid fines from mother liquor that includes such fines, the mother liquor is fed to a settlement drum at above atmospheric pressure. The mother liquor having a lower concentration of carboxylic fines than that fed to the settlement drum is then removed, wherein the mother liquor removal occurs at a point above the point at which the mother liquor containing fines is fed to the settlement drum. In a system for performing the separation process, a settlement drum has an inlet for mother liquor with carboxylic acid fines and an outlet for mother liquor having a lower concentration of carboxylic acid fines content than that of the mother liquor introduced via the inlet. The settlement drum is configured to operate at above atmospheric pressure and the outlet is located at a point in the settlement drum above the inlet.

Abstract: In a process for the separation of carboxylic acid from a slurry in a solvent, a slurry with crystals of carboxylic acid is supplied to a filter operating at pressure and at a temperature above the atmospheric boiling point of the solvent. Inert gas is mixed with the solvent and the mixture is supplied to the filter. A cake of separated crystals is removed from the filter. Inert gas removed from the filter is not recycled. In a system for performing such separation, a pressure filter device has a slurry inlet, and an outlet. Means for mixing inert gas and solvent, and means for supplying the mixture to the pressure filter are provided. The pressure filter device is configured to operate at pressure and at a temperature above the atmospheric boiling point of the solvent. The system does not include means for recycling inert gas removed from the filter.