Pioneer Energy Inc.

Sam G Michael

Robert M Zubrin

Gevorg Sargsyan

The present invention is a natural gas steam reforming method for generating an output gas mixture of carbon dioxide and hydrogen, including the following steps. (1) Combusting a portion of the natural gas with an oxidizing agent to generate heat, superheated steam, and a gas mixture of carbon dioxide, carbon monoxide, and hydrogen. (2) Steam reforming the gas mixture with additional superheated steam under steam-rich conditions to transform a remaining portion of the natural gas into carbon dioxide, carbon monoxide, and hydrogen. (3) Water-gas-shifting any residual carbon monoxide into additional carbon dioxide and additional hydrogen by utilizing a water-gas-shift catalyst downstream of the steam reforming step, thereby producing an effluent gas mixture that is predominantly carbon dioxide and hydrogen. (4) Boiling water in a top-to-bottom linear countercurrent heat exchanger to generate the superheated steam by transferring heat released in the water-gas-shifting step, where as the water is gravitationally and thermally stratified from top to bottom with a top portion boiling into steam, the steam continues to rise and is additionally heated in the top-to-bottom linear countercurrent heat exchanger. (5) And, utilizing the superheated steam produced as a reactant in the steam reforming step and the water-gas-shifting step to assist in reformation of the natural gas into carbon dioxide and hydrogen.

Natural gas steam reforming method with linear countercurrent heat exchanger

The present invention is natural gas steam reforming apparatus for generating an output gas mixture of carbon dioxide and hydrogen. The apparatus is made from two enclosures. A first enclosure contains a source of water, superheated steam, and channels, located within a lower portion of the first enclosure, which contain a water-gas-shift catalyst for converting CO into COand H. The heat from hot gas flowing through the channels is released into the first enclosure to boil the water to generate the superheated steam. A second enclosure, contained within an upper portion of the first enclosure, includes a steam inlet for receiving the superheated steam from the first enclosure; a combustion chamber; and a reformation chamber. The combustion chamber is used for combusting a portion of the natural gas to generate additional steam, heat, and a hot gas mixture of CO, CO, and H. The reformation chamber is used for steam reforming a remaining portion of the natural gas to generate additional hot gas mixture of CO, CO, and H. The hot gas mixture is directed through the channels installed in the first enclosure in which the water-gas-shift catalyst converts residual CO into additional COand additional H, to produce an output gas mixture of carbon dioxide and hydrogen. In the present invention, the first and second enclosures function as a top-to-bottom linear countercurrent heat exchanger.

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Parker, CO, United States of America

Sam G Michael