Praxair Technology, Inc.

Sadashiv M Swami

Richard M Kelly

David Frisbee Suggs

Sean Michael Kelly

Michael J Collins

Philip Alexander Barrett

John D Peck

Arthur C Selover

Jerome Jankowiak

Lane A Keser

Richard Martin Kelly

David F Suggs

Jerome T Jankowiak

A method of operating an oxygen transport membrane based reforming system employing one or more packs of thermally coupled panels of reformer tubes and oxygen transport membrane ('OTM') reactors close to thermo-neutral point is provided. The method produces syngas by converting a hydrocarbon-containing feed, such as natural gas in the reformer tubes of a pack by endothermic steam reforming reactions. The heat required for endothermic reforming reactions is provided by exothermic oxidizing reactions occurring inside the OTM reactors of the pack. At a thermo-neutral point the heat released by exothermic reactions matches the heat required to support endothermic reactions and heat losses in the pack. The method modulates the flow rate of hydrocarbon-containing feed and/or steam-to-carbon ratio of the combined feed to the pack to maintain the surface temperature of oxygen transport membrane reactors below a target maximum temperature. The syngas product oxygen-to-carbon ratio is maintained within a desired target range such that the OTM based reforming system is operated close to thermo-neutral point.

Method of thermally-stabilizing an oxygen transport membrane-based reforming system

A high purity ceramic oxygen generator incorporating a module utilizing a plurality of tubular ceramic membrane elements and configured to operate in: (i) a pressurizing mode to separate oxygen from an oxygen containing feed stream when an electric potential difference is applied to induce oxygen ion transport in an electrolyte thereof; and (ii) an idle mode when the electric potential difference is removed. The ceramic oxygen generator further includes one or more manifolds as well as one or more automatic purge valves located upstream of the oxygen receiving tank. The purge valve is opened for a pre-set duration upon initiation of the pressurization mode to purge any nitrogen or other contaminating gas that diffuses into the ceramic oxygen generator during idle mode thereby ensuring the desired purity level of oxygen is received by the oxygen receiving tank.

High purity ceramic oxygen generator

A method and apparatus for controlling the electrical power applied to an electrically driven oxygen separation device having one or more composite membrane elements to separate oxygen from an oxygen containing feed. The composite membrane elements have a resistance increasing during the operation thereof that would act to reduce oxygen output if applied voltage were held constant. In order to increase the time interval for renewing the composite membrane elements, the electrical potential difference is controlled such that the electric current drawn by the elements remains at a substantially constant level by increasing the electrical potential difference as the resistance increases until a predetermined voltage level is reached. Once this level is obtained, the electrical potential difference is maintained at a constant level and the electric current being drawn and the oxygen output is allowed to decay to a predetermined low level after which the element or elements are replaced.

Control method and apparatus

A method and apparatus for supplying oxygen to meet a user demand in which oxygen is separated from air by an electrically driven oxygen separation device to supply oxygen to meet the user demand and to charge an adsorbent bed with all or part of the separated oxygen. When a user demand exists, oxygen can be supplied from both the electrically driven oxygen separation device and from oxygen desorbed from the adsorbent bed.

Oxygen supply method and apparatus

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Tonawanda, NY, United States of America

Sadashiv M Swami