US 4,792,384 AGranted

Method and apparatus for operating a fuel cell in combination with an electrochemical cell to produce a chemical product

AssigneeUnited Technologies Corporation

InventorsAlexander H. Levy, Kenneth Lipman

Life of this patent

Estimating the term…

Loading patent…

Abstract

A method and apparatus is disclosed for operating a fuel cell 14 producing electrical energy in combination with an electrochemical cell 12 using electrical energy to produce a chemical product. The electrolysis cell produces hydrogen for use as a fuel in the fuel cell and is linked with the fuel cell by a direct current converter 16 which allows the fuel cell to operate between an upper voltage limit and a lower voltage limit. The direct current converter 16 employs a gated switch means, such as a thyristor 98, to intermittently pass electrical power from the fuel cell to the electrochemical cell such that the voltage drop across the direct current converter is equal to the difference in voltage between the fuel cell and the electrochemical electrolysis cell.

Claims14

Dependent claims

An apparatus for carrying out an electrochemical process which comprises:

an electrochemical electrolysis cell which uses input electrical power at a first voltage and a first current to produce a chemical product and hydrogen;
at least one fuel cell which utilizes hydrogen to produce output electrical power at a second voltage which is independent of the voltage of the electrochemical cell and a second current;
means for supplying the hydrogen produced by the electrolysis cell to the fuel cell for consumption of at least a portion of the hydrogen by the fuel cell;
and,
regulator means responsive to the power produced by the fuel cell and to the hydrogen available to the fuel cell for supplying output power received from the fuel cell as input power at the first voltage to the electrochemical cell, said means being electrically connected to the fuel cell and the electrochemical cell and said means employing a direct current converter having gated switch means which intermittently passes current for regulating the electrical power received from the fuel cell by intermittently flowing current between the fuel cell and the electrolysis cell through the gated switch means to adjust the current and voltage supplied by the fuel cell so that the voltage change across said regulator means is equal to the different between the first voltage and the second voltage.

2 more elements

A method for operating a first electrochemical fuel cell in combination with a second electrochemical electrolysis cell, the fuel cell consuming hydrogen to produce electrical energy and having a voltage characteristic that decreases with current and the electrolysis cell having a voltage characteristic that increases with current and producing both hydrogen and a chemical product as a result of the consumption of electrical energy, which comprises:

operating the electrolysis cell at a first current and at a first voltage to produce hydrogen and a chemical product through electrolysis;
supplying the hydrogen produced by the electrolysis cell to the fuel cell;
operating the fuel cell to consume hydrogen and produce power at a second current and at a second voltage which is independent of the voltage of the electrochemical cell;
sensing the power output of the fuel cell;
converting the power output of the fuel cell at the second current and the second voltage to a third current and an output voltage in a direct current converter responsive to the output power of the fuel cell and to the hydrogen available to the fuel cell, the direct current converter having a gated switch means for passing electrical current from the fuel cell intermittently through the gated switch means of the direct current converter to the electrochemical cell to enable the direct current converter to establish a voltage change through the converter to match the output voltage of the direct current converter to the first voltage of the electrolysis cell;
and
supplying the third current to the electrolysis cell to provide at least a portion of the current required to produce hydrogen and the chemical product with said first current.

4 more elements

Dependencies are inferred from the claim text.