Patents by Inventor Limin Ren

Limin Ren 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: 11498062
    Abstract: Methods and phosphorus-containing solid catalysts for catalyzing dehydration of cyclic ethers (e.g., furans, such as 2,5-dimethylfuran) and alcohols (e.g., ethanol and isopropanol). The alcohols and cyclic ethers may be derived from biomass. One example includes a tandem Diels-Alder cycloaddition and dehydration of biomass-derived 2,5-dimethyl-furan and ethylene to renewable p-xylene. The phosphorus-containing solid catalysts are also active and selective for dehydration of alcohols to alkenes.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: November 15, 2022
    Assignees: Regents of the University of Minnesota, University of Massachusetts Amherst, University of Delaware
    Inventors: Hong Je Cho, Wei Fan, Michael Tsapatsis, Paul J. Dauenhauer, Limin Ren, Raul Lobo
  • Patent number: 10919030
    Abstract: Forming a diene includes contacting a reactant including at least one of a cyclic ether and a diol with a heterogeneous acid catalyst to yield a reaction mixture including a diene. The heterogeneous acid catalyst includes at least one of a Lewis acid catalyst, a supported Lewis-acid catalyst, a Brnsted acid catalyst, a solid acid catalyst, a supported phosphoric acid catalyst, and a sulfonated catalyst. The dehydration of cyclic ethers and diols with high selectivity to yield dienes completes pathways for the production of dienes, such as isoprene and butadiene, from biomass in high yields, thereby promoting economical production of dienes from renewable resources.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: February 16, 2021
    Assignee: Regents of the University of Minnesota
    Inventors: Omar A. Abdelrahman, Charles S. Spanjers, Dae Sung Park, Michael Tsapatsis, Limin Ren, Paul J. Dauenhauer
  • Publication number: 20190345078
    Abstract: Forming a diene includes contacting a reactant including at least one of a cyclic ether and a diol with a heterogeneous acid catalyst to yield a reaction mixture including a diene. The heterogeneous acid catalyst includes at least one of a Lewis acid catalyst, a supported Lewis-acid catalyst, a Brnsted acid catalyst, a solid acid catalyst, a supported phosphoric acid catalyst, and a sulfonated catalyst. The dehydration of cyclic ethers and diols with high selectivity to yield dienes completes pathways for the production of dienes, such as isoprene and butadiene, from biomass in high yields, thereby promoting economical production of dienes from renewable resources.
    Type: Application
    Filed: September 29, 2017
    Publication date: November 14, 2019
    Inventors: Omar A. Abdelrahman, Charles S. Spanjers, Dae Sung Park, Michael Tsapatsis, Limin Ren, Paul J. Dauenhauer
  • Publication number: 20190344252
    Abstract: Methods and phosphorus-containing solid catalysts for catalyzing dehydration of cyclic ethers (e.g., furans, such as 2,5-dimethylfuran) and alcohols (e.g., ethanol and isopropanol). The alcohols and cyclic ethers may be derived from biomass. One example includes a tandem Diels-Alder cycloaddition and dehydration of biomass-derived 2,5-dimethyl-furan and ethylene to renewable p-xylene. The phosphorus-containing solid catalysts are also active and selective for dehydration of alcohols to alkenes.
    Type: Application
    Filed: September 29, 2017
    Publication date: November 14, 2019
    Inventors: Hong Je Cho, Wei Fan, Michael Tsapatsis, Paul J. Dauenhauer, Limin Ren, Raul Lobo
  • Patent number: 9334170
    Abstract: The present invention relates to a process for the preparation of a zeolitic material having a CHA framework structure, said zeolitic material comprising zeolite crystals having a core-shell structure, wherein said process comprises the steps of (1) providing a mixture comprising one or more sources for Z2O5, one or more sources for X2O3, optionally one or more structure directing agents, and seed crystals having a CHA framework structure, wherein the CHA framework structure of the seed crystals comprises YO2, X2O3, and optionally Z2O5, and wherein the seed crystals have a diameter of 450 nm or greater; (2) crystallizing the mixture provided in (1) to afford zeolite crystals comprising a core of seed crystal provided in step (1) and a shell crystallized on the seed crystal; wherein Z is a pentavalent element, Y is a tetravalent element, and X is a trivalent element.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: May 10, 2016
    Assignees: BASF SE, Tokyo Institute of Technology
    Inventors: Bilge Yilmaz, Ulrich Müller, Feng-Shou Xiao, Takashi Tatsumi, Dirk de Vos, Xinhe Bao, Weiping Zhang, Hermann Gies, Hiroyuki Imai, Bart Tijsebaert, Limin Ren, Chengguan Yang
  • Publication number: 20130101503
    Abstract: The present invention relates to a process for the preparation of a zeolitic material having a CHA framework structure, said zeolitic material comprising zeolite crystals having a core-shell structure, wherein said process comprises the steps of (1) providing a mixture comprising one or more sources for Z2O5, one or more sources for X2O3, optionally one or more structure directing agents, and seed crystals having a CHA framework structure, wherein the CHA framework structure of the seed crystals comprises YO2, X2O3, and optionally Z2O5, and wherein the seed crystals have a diameter of 450 nm or greater; (2) crystallizing the mixture provided in (1) to afford zeolite crystals comprising a core of seed crystal provided in step (1) and a shell crystallized on the seed crystal; wherein Z is a pentavalent element, Y is a tetravalent element, and X is a trivalent element.
    Type: Application
    Filed: September 14, 2012
    Publication date: April 25, 2013
    Applicants: Tokyo Institute of Technology, BASF SE
    Inventors: Bilge Yilmaz, Ulrich Müller, Feng-Shou Xiao, Takashi Tatsumi, Dirk de Vos, Xinhe Bao, Weiping Zhang, Hermann Gies, Hiroyuki Imai, Bart Tijsebaert, Limin Ren, Chengguan Yang