Pre-processing assembly for pre-processing fuel feedstocks for use in a fuel cell system

Abstract

A pre-processing assembly and method for processing fuel feedstock containing oxygen and hydrocarbons having higher and lower hydrocarbon content for a fuel cell, wherein the pre-processing assembly has a deoxidizing bed for reducing oxygen in the fuel feedstock and a pre-reforming bed for reducing higher hydrocarbon content in the fuel feedstock and wherein the deoxidizing bed and the pre-reforming bed are disposed within a common reaction vessel such that the fuel feedstock first passes through the deoxidizing bed and thereafter through the pre-reforming bed. The pre-reforming assembly may further include a propane processor bed for processing propane and propylene in the fuel feedstock, where the propane processor bed is disposed within the common reaction vessel with the deoxidizing bed and the pre-reforming bed.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates to processing of fuel feedstocks containing hydrocarbons for use in fuel cell systems and, in particular, to pre-processing assemblies for performing pre-processing of the fuel feedstocks. [0002] A fuel cell is a device which directly converts chemical energy stored in hydrocarbon fuel into electrical energy by means of an electrochemical reaction. Generally, a fuel cell comprises an anode and a cathode separated by an electrolyte, which serves to conduct electrically charged ions. Molten carbonate fuel cells operate by passing a reactant fuel gas through the anode, while oxidizing gas is passed through the cathode. In order to produce a useful power level, a number of individual fuel cells are stacked in series with an electrically conductive separator plate between each cell. [0003] Current fuel cells require as the reactant fuel gas a clean gas composed of hydrogen or a mixture of hydrogen and carbon monoxide. The reactant...

AI Technical Summary

Benefits of technology

[0014] In accordance with the principles of the present invention, the above and other objectives are realized in a pre-processing assembly and method for pre-processing a fuel feedstock containing hydrocarbons including higher hydrocarbon content in which a common vessel houses both a deoxidizing unit for reducing the oxygen content in the fuel feedstock and a pre-forming unit for receiving the fuel feedstock after passage through the deoxidizing unit and for reducing the higher hydrocarbon content in the fuel feedstock. In performing this pre-processing the assembly also reduces a portion of the lower hydrocarbon content in the feedstock and increases the hydrogen content.

Problems solved by technology

In the pre-reforming assembly, the reforming reaction is a conversion process which may inadvertently result in carbon formation based on fuel composition and steam.

This reduces the life of the pre-reforming assembly.

Although fuel feedstocks are typically desulfurized in a desulfurizer unit before being carried to the pre-reforming assembly, high sulfur concentration and the propylene in the fuel feedstocks reduce the capacity of the desulfurizer unit.

As can be appreciated, conventional pre-processing of fuel feedstocks is complex and costly, due to the need for additional units or special components for supplying hydrogen, for reducing carbon formation and for removing propylene and an additional unit to remove oxygen entering into the pre-reforming assembly.

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