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@PHDTHESIS{Ehmann:987838,
author = {Ehmann, Kira Ruth},
othercontributors = {Leitner, Walter and Liauw, Marcellus},
title = {{H}omogenkatalysierte {H}ydrierung von {K}ohlenstoffdioxid
zu {A}meisensäure in {R}eaktionssystemen mit einer und zwei
flüssigen {P}hasen},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2024-05869},
pages = {1 Online-Ressource : Illustrationen},
year = {2024},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, RWTH Aachen University, 2024},
abstract = {The conversion of carbon dioxide with hydrogen to formic
acid represents a synthesis route based on renewable raw
materials that can contribute to the defossilization of the
chemical industry. The focus of existing homogeneously
catalyzed reaction systems is mainly on the development of
efficient catalysts in reaction systems with a single liquid
phase. However, for the large-scale production of formic
acid, in addition to active and selective catalysts, their
separation is also of great importance. A well-known
strategy for this is the concept of liquid/liquid multiphase
catalysis. Although such multiphase catalyzed reaction
systems already exist, the possible influence of the second
liquid phase on the final formic acid concentration and the
reaction rate has not yet been clarified. In this work, this
influence of the second liquid phase on the catalytic
conversion is therefore investigated using a selected model
reaction system with one and two liquid phases by means of a
specially designed mini plant. The model reaction system
with one liquid phase uses 4-methyl-2-pentanol as the
organic solvent, in which the amine (triethylamine) and the
ruthenium-phosphine (pre)catalyst are located. In this
reaction system, lowering the temperature or increasing the
total pressure according to the principle of LE CHATELIER
causes an increased formation of formic acid. Despite the
stabilizing effect of the amine in relation to the formic
acid, an increasing proportion of amine leads to a decrease
in the formic acid concentration. It has been shown that
thermodynamic equilibrium is not achieved due to inhibition.
For the reaction system with two liquid phases, water is
added as an additional phase to the model reaction system
with one liquid phase. In this reaction system, unlike
before, an increase in the amount of amine leads to a higher
formic acid concentration. The addition of water to the
reaction system with a liquid phase causes the inhibition to
be removed. For the model reaction system investigated, the
addition of the second liquid phase therefore has a positive
influence on the catalytic conversion. In addition, a
reaction system that is as analogous as possible
(Ruthenium-phosphine-(pre)catalyst/4-methyl-2-pentanol/N-methyldiethanolamine)
was developed, in which an independently separating product
phase only forms through the formation of the product during
the reaction. This reaction system conceptually combines the
reaction systems with one and two liquid phases. Regarding
the influence of the composition of the liquid phase on the
catalytic conversion, it behaves, according to an initial
investigation, like the reaction system with two liquid
phases.},
cin = {154110 / 150000},
ddc = {540},
cid = {$I:(DE-82)154110_20140620$ / $I:(DE-82)150000_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2024-05869},
url = {https://publications.rwth-aachen.de/record/987838},
}
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