Catalyst feed systems and processes utilizing such systems are described herein. Some embodiments disclosed herein relate to a process for improving the flowability of catalyst in a catalyst feed system, including providing a catalyst feed vessel with at least one heat exchange system for maintaining the catalyst system temperature below a critical flow temperature. Also disclosed is a catalyst feed system for the polymerization of olefins including a catalyst feed vessel; and a heat exchange system for maintaining a temperature of a catalyst within the catalyst feed vessel. Additionally disclosed is a process for polymerization of olefins including maintaining a supported catalyst in a catalyst feed vessel below a critical flow temperature of the catalyst; feeding the catalyst to a polymerization reactor; and contacting the catalyst with an olefin to form a polyolefin.