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@PHDTHESIS{Albrecht:1023677,
      author       = {Albrecht, Pascal},
      othercontributors = {Klankermayer, Jürgen and Oppel, Iris Marga},
      title        = {{D}evelopment and upscaling of the catalytic urea synthesis
                      from formamide and ammonia, and the hydrogenation of
                      levulinic acid},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Aachen},
      publisher    = {RWTH Aachen University},
      reportid     = {RWTH-2025-10661},
      pages        = {1 Online-Ressource : Illustrationen},
      year         = {2025},
      note         = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
                      University 2026; Dissertation, RWTH Aachen University, 2025},
      abstract     = {This thesis deals with the development and design of
                      technical laboratory plants to perform catalytic urea
                      synthesis and levulinic acid hydrogenation. The starting
                      point is a novel catalytic system that enables the effective
                      production of urea starting from carbon monoxide or carbon
                      dioxide as the C1 building block via the intermediate
                      formamide. For the hydrogenation of organic carboxylic
                      acids, and in particular bio-based levulinic acid, a
                      tailor-made ruthenium-triphos catalyst was used, which
                      because of its unique properties, enables this extremely
                      demanding chemical transformation. Based on previous
                      fundamental catalysis research on small scale, systematic
                      optimization studies were carried out with the aim of
                      maximizing the product yields and catalyst recycling options
                      in the translation process. Within the scope of this thesis,
                      the specific requirements for the plants, the selection of
                      suitable components and precise control of the process
                      parameters were addressed in detail. Chapter 2.1 discusses
                      the novel possibility to produce urea and the subsequent
                      translation to a mini plant. The focus was on the central
                      reaction pathway for urea synthesis starting from formamide.
                      The reaction parameters temperature, time, as well as the
                      amounts of reagents used were investigated on a larger scale
                      at a laboratory plant tailored for two reaction pathways,
                      eventually allowing to determine the optimal process
                      conditions for maximum product yield. Chapter 2.2 deals with
                      the challenge to establish a complete value chain starting
                      from biomass via the platform chemical levulinic acid to
                      various valuable consumer products. The hydrogenation of
                      levulinic acid, which is in the focus of this thesis, was
                      transferred to a larger scale at a tailored plant. To
                      optimize the product yields of this process, the complex
                      interaction of reaction parameters time, hydrogen pressure,
                      temperature, as well as substrate and catalyst amounts were
                      investigated. The levulinic acid produced in the biorefinery
                      of the Institute of Applied Process Engineering at RWTH
                      Aachen University with a purity of approximately $75wt\%$
                      was successfully converted directly into γ-valerolactone,
                      1,4-pentanediol, and 2-methyltetrahydrofuran. Finally, a
                      catalyst immobilization concept was developed that can be
                      used in the future for the continuous hydrogenation of
                      levulinic acid in flow reactors.},
      cin          = {154310 / 150000},
      ddc          = {540},
      cid          = {$I:(DE-82)154310_20190725$ / $I:(DE-82)150000_20140620$},
      typ          = {PUB:(DE-HGF)11},
      doi          = {10.18154/RWTH-2025-10661},
      url          = {https://publications.rwth-aachen.de/record/1023677},
}