Patents by Inventor Ralf Kriegel

Ralf Kriegel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11808238
    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.
    Type: Grant
    Filed: October 23, 2020
    Date of Patent: November 7, 2023
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventor: Ralf Kriegel
  • Publication number: 20220372936
    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.
    Type: Application
    Filed: October 23, 2020
    Publication date: November 24, 2022
    Inventor: Ralf KRIEGEL
  • Patent number: 10871130
    Abstract: The invention relates to a combustion engine and to a process for producing energy by means of expansion work in combustion engines. The invention is based on the problem of providing a possibility for supplying oxygen to the combustion space of a self-compacting combustion engine in an energy-efficient manner. According to the invention, with an arrangement for carrying out an intensified combustion for automatically increasing pressure of the combustion gases and using them in a combustion engine for performing mechanical work, the above-stated problem is solved in that an oxygen storage material is present in the combustion space so that a self-compressing combustion process is made possible by storing the oxygen in the oxygen storage material in the combustion space.
    Type: Grant
    Filed: December 23, 2014
    Date of Patent: December 22, 2020
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E. V.
    Inventors: Ralf Kriegel, Robert Kircheisen, Markku Lampinen, Ville Ristimaeki
  • Patent number: 10549994
    Abstract: The invention relates to a method and an arrangement for the continuous production of compressed oxygen from air using mixed conducting ceramic membranes. The aim of the invention is to provide a way of isolating pure oxygen from the air and compressing said oxygen to pressures above the ambient pressure, without using mechanical or electromechanical compression of air or oxygen. To achieve this aim, according to the invention water in various aggregate states is conducted in a circuit and the configuration of the equipment is designed such that the desired high oxygen pressure is produced in a separate area from the membrane module and the oxygen produced is prevented from mixing with the freshly produced water vapour.
    Type: Grant
    Filed: October 27, 2015
    Date of Patent: February 4, 2020
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E. V.
    Inventors: Ralf Kriegel, Robert Kircheisen, Matthias Schulz, Claudia Sonnenberg
  • Publication number: 20180334957
    Abstract: The aim of the invention is to significantly increase the electrical efficiency or the proportion of the effective work of gas turbines, even in small gas turbines or microsize gas turbines having a simple design. According to the invention, the drawbacks of the prior art are overcome using wet combustion with oxygen, the oxygen being supplied via mixed-conducting ceramic membranes. The driving force needed for the oxygen to penetrate is created by lowering the partial pressure of the oxygen on the permeate side of the membrane module (5), and the energy required therefor is taken from the process energy produced in the gas turbine process.
    Type: Application
    Filed: November 17, 2016
    Publication date: November 22, 2018
    Inventor: Ralf KRIEGEL
  • Patent number: 9901866
    Abstract: The invention relates to a membrane separation process for energy-efficient generation of oxygen from fresh air. In the process, mixed conducting membranes in vacuum operation are used, the fresh air is discharged as waste air after separation of the oxygen, at least 85% of the thermal energy required for heating the fresh air is acquired by utilizing the waste heat of the waste air and/or of the obtained oxygen, the rest of the heating of the fresh air being realized through external energy supply, and a ratio of fresh air to generated oxygen in normal operation is adjusted to a range of from 6:1 to 25:1.
    Type: Grant
    Filed: July 15, 2014
    Date of Patent: February 27, 2018
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E. V.
    Inventor: Ralf Kriegel
  • Publication number: 20170320733
    Abstract: The invention relates to a method and an arrangement for the continuous production of compressed oxygen from air using mixed conducting ceramic membranes. The aim of the invention is to provide a way of isolating pure oxygen from the air and compressing said oxygen to pressures above the ambient pressure, without using mechanical or electromechanical compression of air or oxygen. To achieve this aim, according to the invention water in various aggregate states is conducted in a circuit and the configuration of the equipment is designed such that the desired high oxygen pressure is produced in a separate area from the membrane module and the oxygen produced is prevented from mixing with the freshly produced water vapour.
    Type: Application
    Filed: October 27, 2015
    Publication date: November 9, 2017
    Inventors: Ralf KRIEGEL, Robert KIRCHEISEN, Matthias SCHULZ, Claudia SONNENBERG
  • Patent number: 9725662
    Abstract: Disclosed are a method and a membrane module for the separation of oxygen from air during biomass gasification. The method comprises employing a membrane module as disclosed herein and using gas exiting the membrane module to heat incoming fresh air, more than 50% of heat energy contained in the gas exiting the membrane module being utilized to preheat the fresh air. The fresh air is further heated to a temperature of from 800° C. to 900° C. by directly feeding combustion gas or synthesis gas from the biomass gasification into a combustion space of the membrane module.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: August 8, 2017
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E. V.
    Inventor: Ralf Kriegel
  • Publication number: 20170030304
    Abstract: The invention relates to a combustion engine and to a process for producing energy by means of expansion work in combustion engines. The invention is based on the problem of providing a possibility for supplying oxygen to the combustion space of a self-compacting combustion engine in an energy-efficient manner. According to the invention, with an arrangement for carrying out an intensified combustion for automatically increasing pressure of the combustion gases and using them in a combustion engine for performing mechanical work, the above-stated problem is solved in that an oxygen storage material is present in the combustion space so that a self-compressing combustion process is made possible by storing the oxygen in the oxygen storage material in the combustion space.
    Type: Application
    Filed: December 23, 2014
    Publication date: February 2, 2017
    Applicant: Fraunhofer-Gesellschaft zur Foerderung der ange- wandten Forschung e.V.
    Inventors: Ralf KRIEGEL, Robert KIRCHEISEN, Markku LAMPINEN, Ville RISTIMAEKI
  • Publication number: 20160136571
    Abstract: The invention relates to a membrane separation process for energy-efficient generation of oxygen from fresh air. In the process, mixed conducting membranes in vacuum operation are used, the fresh air is discharged as waste air after separation of the oxygen, at least 85% of the thermal energy required for heating the fresh air is acquired by utilizing the waste heat of the waste air and/or of the obtained oxygen, the rest of the heating of the fresh air being realized through external energy supply, and a ratio of fresh air to generated oxygen in normal operation is adjusted to a range of from 6:1 to 25:1.
    Type: Application
    Filed: July 15, 2014
    Publication date: May 19, 2016
    Inventor: Ralf KRIEGEL
  • Publication number: 20160040081
    Abstract: The invention relates to a method and a membrane module for process-integrated oxygen generation during biomass gasification, wherein the oxygen is generated at high temperature via mixed conducting ceramic membranes. It is the object of the invention to provide a possibility for energy-efficient oxygen generation in biomass gasification for increasing the efficiency of the overall process. According to the invention, the disadvantages of the prior art are remedied in that a membrane module is heated directly by the synthesis gas from the biomass gasification. However, this heating should only meet less than 20%, typically less than 10% and, under optimal conditions, only approximately 5% of the heat requirement of the membrane module. The predominant portion of the heat required to heat the fresh air is taken from the exhaust air of the membrane module through heat exchange.
    Type: Application
    Filed: April 1, 2014
    Publication date: February 11, 2016
    Applicant: FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
    Inventor: Ralf KRIEGEL
  • Publication number: 20120201974
    Abstract: A method for high temperature resistant bonding of oxygen permeable oxide ceramics of substituted alkaline earth cobaltates by doping assisted diffusive reaction sintering includes providing at least one joining surface of the oxygen permeable ceramics with a Cu-containing additives. At least a join area of the oxygen permeable ceramics is subsequently heated, under loading through forces, to a temperature up to 250 K below a customary sintering temperature of the oxygen-permeable ceramics. The join area is held under the loading at the temperature for 0.5 to 10 hours.
    Type: Application
    Filed: October 14, 2010
    Publication date: August 9, 2012
    Applicant: Fraunhofer Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Ralf Kriegel, Robert Kircheisen, Katrin Ritter