Using a Heat Balance to Determine Solid Circulation Rate in a Cold Flow Plug Flow Reactor with Internal Recirculation

A novel system for pressurized chemical looping (PCL) called a plug flow with internal recirculation (PFIR) reactor is being developed at CanmetENERGY in collaboration with Hatch Ltd. The PFIR is a novel, compact, annular fluidized bed configuration incorporating directional jets that circulate solids between fluidized bed segments in a single vessel. This PCL reactor design eliminates the need for two separate fluidized bed reactors and the associated external solids transfer equipment. It allows for relatively high oxygen carrier circulation rates between the air and fuel reactors, which is an important design challenge for PCL systems. Demonstrating that high oxygen carrier solid circulation rates can be achieved in a 0.61 m outer diameter cold flow PFIR system is a key milestone in confirming that PFIR reactors can be used for PCL. Studies on solid circulation rate in the PFIR are being used to better understand this unique reactor design and to validate a computational particle fluid dynamics (CPFD) model of the PFIR.

A technique using a heat balance to determine solid circulation rate has been investigated. Particles are heated in situ with a heater and the temperature is measured at the transition points between the reactor sections. Parameters that affect gas momentum will influence the solid circulation rate in the PFIR. For this reason, the effect of PFIR geometry and operating conditions, such as pressure at the bottom of the bed, on solid circulation rate is examined.