Method for process-integrated oxygen supply of a hydrogen circulation engine comprising recirculation of a noble gas

Patent metadata

Field	Value
Publication number	US-11808238-B2
Application number	US-202017771389-A
Country	US
Kind code	B2
Filing date	Oct 23, 2020
Priority date	Oct 25, 2019
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

Abstract

A method for supplying hydrogen-operated internal combustion engines with oxygen, wherein an inert gas is cycled. An economical local supply of pure oxygen for a closed-cycle hydrogen engine with argon cycling is realized by separating the oxygen from the atmosphere without relying on the useful work of the engine. OSM ceramics and exhaust gas heat and low oxygen partial pressure of the exhaust gas are used to generate oxygen. Two reactors filled with OSM ceramics are used, these reactors being alternately purged with exhaust gas and regenerated with air. Losses of inert gases and the entry of atmospheric nitrogen are avoided by intermediate purging with steam. The steam is generated by the heat of the exhaust gas or exhaust air. A mixture of water vapor, inert gas and oxygen is formed during purging. Subsequently, the oxygen content in the gas phase is markedly increased since water vapor is condensed out.

First claim

The invention claimed is:

1. A method for operating a closed-cycle hydrogen engine with an oxidizer gas comprising oxygen and an inert gas not participating in the combustion, the method comprising:
cycling a gas mixture, and separating a combustion-product water by condensing out, by performing the steps of:
alternatingly operating, in two phases, at least two reactors, each filled with oxygen-storage material to obtain oxygen needed for combustion directly from air surrounding the closed-cycle hydrogen engine, including:
in a first phase, filling the at least two reactors with air so that oxygen contained in the air is stored in the oxygen-storage material, and
in a second phase purging the at least two reactors which were enriched with the oxygen in the oxygen-storage material with the gas mixture expelled from the combustion engine so that the gas mixture is enriched with the oxygen stored in the oxygen-storage material;

separating water from the oxygen-enriched gas mixture resulting from the second phase by condensing the water out to produce the oxidizer gas containing the oxygen and the inert gas;
supplying the oxidizer gas to the closed-cycle hydrogen engine.

2. The method according to claim 1 , wherein an OSM ceramic with a composition Ca 0.5 Sr 0.5 Fe 0.5 Mn 0.5 O 3 synthesized from individual oxides and carbonates by solid state reaction is used.

3. The method according to claim 1 , wherein any desired purge time of the at least two reactors is adjustable by a bypass valve and the oxygen to be stored in the oxygen-storage material is accordingly adjustable in any desired manner.

4. The method according to claim 1 , wherein the gas mixture supplied for cycling after the second phase has an exhaust gas heat which is utilized for generating low-pressure steam.

5. The method according to claim 1 , wherein an oxygen-depleted air results in the first phase and has a heat which is utilized for generating low-pressure steam.

6. The method according to claim 1 , wherein a membrane gas storage for storing the oxidizer gas is contained in the circuit and serves to homogenize a mixture of the oxidizer gas and enables a reliable starting of the closed-cycle hydrogen engine.

7. The method according to claim 1 , further comprising using switchover valves for switching between the first and second phases, inputs to the at least two reactors are arranged upstream of the at least two reactors and outputs of the at least two reactors are arranged downstream of the at least two reactors, wherein the inputs and outputs of the at least two reactors during the first phase are switched to outputs and inputs of the at least two reactors in the second phase.

8. The method according to claim 1 , wherein losses of inert gas and entry of atmospheric nitrogen are prevented by an intermediate purge with low-pressure steam.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Kriegel Ralf

Classifications

• F02M25/12 Primary

  the apparatus having means for generating such gases (using rays and simultaneously generating ozone F02M27/06) · CPC title

• C01G49/0072

  containing manganese · CPC title

• F02B43/12

  Methods of operating · CPC title

• F02B47/10 Primary

  Circulation of exhaust gas in closed or semi-closed circuits, e.g. with simultaneous addition of oxygen · CPC title

• F02M21/0206

  Non-hydrocarbon fuels, e.g. hydrogen, ammonia or carbon monoxide · CPC title