Mass and heat recovery system for a fuel cell power plant

Abstract

A mass and heat recovery system for a fuel cell power plant includes at least one fuel cell for producing electrical energy, hydrocarbon fuel processing components for producing a hydrogen rich reducing fluid for the fuel cell, and a direct mass and heat transfer device for recovering mass and heat such as water vapor leaving the plant. The fuel processing components include an auxiliary burner that provides heat to generate steam and a reformer that receives the steam mixed with a hydrocarbon fuel along with a small amount of air and converts the mixture to a hydrogen rich stream appropriate for supplying hydrogen to the anode electrode. The direct mass and heat transfer device passes a process oxidant stream upstream of the plant in mass transfer relationship with a plant exhaust stream that includes both a cathode exhaust stream and an anode exhaust stream wherein the anode exhaust stream has first been burned in the auxiliary burner so that mass and heat such as water vapor in the plant exhaust stream transfer directly through a mass transfer medium of the device to the process oxidant stream entering the plant. The device includes a separator housing for supporting the transfer medium and for preventing bulk mixing of the streams. An exemplary transfer medium such as a liquid water portion of a water saturated polyflourosulfonic ionomer selectively sorbs a fluid substance consisting of polar molecules such as water molecules from a fluid stream containing polar and non-polar molecules.