Natural gas steam reforming method with linear countercurrent heat exchanger

A method for converting natural gas and water into a synthesis gas mixture of carbon monoxide and hydrogen, comprising the following steps:

• combusting a portion of the natural gas with an oxidizing agent in a combustion chamber to generate heat, superheated steam, and a gas mixture of carbon monoxide and hydrogen, with a minority carbon dioxide;
• steam reforming the gas mixture under steam stoichiometric conditions with additional superheated steam in a second enclosure to transform a remaining portion of the natural gas into the synthesis gas mixture of carbon monoxide and hydrogen, substantially free of carbon dioxide;
• boiling water in a top-to-bottom linear countercurrent heat exchanger in a first enclosure to generate the superheated steam by transferring heat released in the combusting step, wherein 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;
• and
• utilizing the superheated steam produced as a reactant in the steam reforming step to assist in reformation of the natural gas into carbon monoxide and hydrogen, thereby producing an effluent gas mixture that is predominantly carbon monoxide and hydrogen,
• wherein the first enclosure comprises channels in which heat from the combusting step is released into the first enclosure to boil the water to generate superheated steam, said channels located in a lower portion of the first enclosure and partially immersed in boiling water, and extending from a bottom of said second enclosure, the second enclosure contained within an upper portion of the first enclosure.

A method for enabling enhanced oil recovery utilizing natural gas and water, comprising the following steps:

• combusting a portion of the natural gas with an oxidizing agent in a combustion chamber to generate heat, superheated steam, and a gas mixture of carbon dioxide, carbon monoxide, and hydrogen;
• steam reforming the gas mixture with additional superheated steam in a second enclosure to transform a remaining portion of the natural gas into carbon dioxide, carbon monoxide, and hydrogen;
• water-gas-shifting any residual carbon monoxide into additional carbon dioxide and additional hydrogen by utilizing a water-gas-shift catalyst located in channels extending from a bottom of the second enclosure, thereby producing an effluent gas mixture that is predominantly carbon dioxide and hydrogen;
• boiling water in a top-to-bottom linear countercurrent heat exchanger in a first enclosure to generate the superheated steam by transferring heat released in the water-gas-shifting step, wherein 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 which comprises said channels located in a lower portion of the first enclosure and partially immersed in boiling water, and the second enclosure contained within an upper portion of the first enclosure;
• boiling additional water in an external boiler by combusting the natural gas with ambient air to generate additional superheated steam which is fed into the steam reforming step;
• utilizing the superheated steam in the steam reforming step and the water-gas-shifting step to assist in reformation of the natural gas into carbon dioxide and hydrogen;
• separating the carbon dioxide and hydrogen into two streams, one predominantly carbon dioxide and the other predominantly hydrogen;
• and
• compressing the carbon dioxide stream and injecting it into the ground to enable enhanced oil recovery.