Influence of solvent and salt on kinetics and equilibrium of esterification reactions

Pabsch, Daniel; analysis, Johanna Lindfeld Data; analysis, Janika Schwalm Data; analysis, Alexander Strangmann Data; Figiel, Paul; Sadowski, Gabriele; Held, Christoph

doi:10.1016/j.ces.2022.118046

Cited by 8 publications

(28 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This approach was also successfully used in kinetic studies of an esterification reaction with salt influence. [24] However, in contrast to the present work, the model of Lemberg and Sadowski was assuming constant catalyst concentration. The model performance at other catalyst concentrations is unknown.…”

Section: Kinetic Model I -State-of-the-art Approachmentioning

confidence: 72%

“…Both, the activity coefficients and the mole fractions depend on the choice of solvent, whereas the calculated rate constant 𝑘 keeps constant for each composition. This approach was also successfully used in kinetic studies of an esterification reaction with salt influence [24] . However, in contrast to the present work, the model of Lemberg and Sadowski was assuming constant catalyst concentration.…”

Section: Kinetic Model I -State-of-the-art Approachmentioning

confidence: 99%

See 1 more Smart Citation

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

et al. 2022

Self Cite

View full text Add to dashboard Cite

The solvent is of prime importance in biomass conversion as it influences dissolution, reaction kinetics, catalyst activity and thermodynamic equilibrium of the reaction system. So far, activity-based models were developed to predict kinetics and equilibria, but the influence of the catalyst could not be predicted by thermodynamic models. Thus, in this work, the thermodynamic model ePC-SAFT advanced was used to predict the activities of the reactants and of the catalyst at various conditions (temperature, reactant concentrations, γ-valerolactone GVL cosolvent addition, catalyst concentration) for the homogeneously acid-catalyzed esterification of levulinic acid (LA) with ethanol. Different kinetic models were applied, and it was found that the catalyst influence on kinetics could be predicted correctly by simultaneously solving the dissociation equilibrium of H2SO4 catalyst along the reaction coordinate and the relating reaction kinetics to proton activity. ePC-SAFT advanced model parameters were only fitted to reaction-independent phase equilibrium data, but the key reaction properties were determined by one experimental kinetic curve for a set of temperatures, yielding the reaction enthalpy at standard state ∆ 𝑅 𝐻 0 = 11.48 𝑘𝐽 𝑚𝑜𝑙 −1 , activation energy 𝐸 𝐴 = 30.28 𝑘𝐽 𝑚𝑜𝑙 −1 and the intrinsic reaction rate constant k = 0.011 s -1 at 323 K, which is independent of catalyst concentration. The new procedure allowed an a-priori identification of the effects of catalyst, solvent and reactant concentration on LA esterification.

show abstract

Section: Kinetic Model I -State-of-the-art Approachmentioning

confidence: 72%

Section: Kinetic Model I -State-of-the-art Approachmentioning

confidence: 99%

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…The MeOH excess is also necessary to offset adverse effects of NMP, which will be inevitably carried on into the esterification reaction in the circular three‐step process. NMP as a solvent is known to be disadvantageous for the reaction kinetics and the reaction equilibrium of esterification reactions [22] …”

Section: Methodsmentioning

confidence: 99%

Carboxylation of Acetylene without Salt Waste: Green Synthesis of C₄ Chemicals Enabled by a CO₂‐Pressure Induced Acidity Switch

et al. 2023

Self Cite

View full text Add to dashboard Cite

The inherent formation of salt waste in C−H carboxylations is a key obstacle precluding the utilization of CO2 as C1 building block in the industrial synthesis of base chemicals. This challenge is addressed in a circular process for the production of the C4 base chemical dimethyl succinate from CO2 and acetylene. At moderate CO2 pressures, acetylene is doubly carboxylated in the presence of cesium carbonate. Hydrogenation of the C−C triple bond stabilizes the product against decarboxylation. By increasing the CO2 pressure to 70 bar, the medium is reversibly acidified, allowing an esterification of the succinate salt with methanol. The cesium base and the hydrogenation catalyst are regenerated and can be reused. This provides the proof of concept for a salt‐free route to C4 chemicals from biogas (CH4/CO2). The origin of this reversible acidity switch and the critical roles of the cesium base and the NMP/MeOH solvents were elucidated by thermodynamic modeling.

show abstract

“…Dieser kombinierte Effekt von reduzierter Basenkonzentration und hohem CO 2 Druck bewirken einen Wechsel der Acidität des Reaktionsmediums und ermöglichen somit eine säurekatalysierte Veresterung der sonst nicht‐reaktiven Carboxylatsalze. Zudem gleicht der MeOH‐Überschuss die nachteiligen Auswirkungen von NMP auf Gleichgewicht und Kinetik der Veresterungsreaktion aus [22] …”

Section: Methodsunclassified

“…Neben [22] An dieser Stelle sei darauf hingewiesen, dass die hier vorgestellten ePC-SAFT Vorhersagen die chemische Reaktivität von CO 2 noch nicht ausdrücklich berücksichtigen. Es ist davon auszugehen, dass das physikalisch gelöste CO 2 teilweise in die OH-Bindung der Bicarbonate eindringt, was zu Pyrocarbonat-Spezies des Typs Cs-OC(O)OC(O)H führt.…”

unclassified

Salzabfall‐freie Carboxylierung von Acetylen: Grüne Synthese von C₄‐Chemikalien durch einen CO₂‐Druck‐induzierten Aciditätsswitch

et al. 2023

Self Cite

View full text Add to dashboard Cite

Die Vermeidung der Bildung equimolarer Mengen an Salzabfällen ist eine der größten Herausforderungen zur Nutzung von CO 2 als C 1 Baustein in C-H-Carboxylierungsreaktionen. Zur Lösung dieses Problems wurde ein zyklischer Prozess entwickelt, in welchem die industrielle Basischemikalie Dimethylsuccinat aus CO 2 und Acetylen synthetisiert wird. Bei moderatem CO 2 -Druck kann Acetylen mit Cäsiumcarbonat zweifach carboxyliert und das intermediäre Salz durch Hydrierung der C-C-Dreifachbindung stabilisiert werden. Bei 70 bar CO 2 wird das Reaktionsmedium reversibel angesäuert, was die Veresterung des Carboxylatsalzes mit dem Lösemittel Methanol ermöglicht. Die Cäsiumbase und der Hydrierkatalysator können regeneriert und wiederverwendet werden. Dieses Reaktionskonzept eröffnet einen neuen Weg zur Umsetzung von Biogas (CH 4 /CO 2 ) zu industriell relevanten C 4 Basischemikalien. Der reversible Aziditätsswitch, die Rolle der Cäsiumbase so wie die des Lösungsmittelgemisches wurden durch thermodynamische Modellierung aufgeklärt.

show abstract

Influence of solvent and salt on kinetics and equilibrium of esterification reactions

Cited by 8 publications

References 43 publications

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

Carboxylation of Acetylene without Salt Waste: Green Synthesis of C₄ Chemicals Enabled by a CO₂‐Pressure Induced Acidity Switch

Salzabfall‐freie Carboxylierung von Acetylen: Grüne Synthese von C₄‐Chemikalien durch einen CO₂‐Druck‐induzierten Aciditätsswitch

Contact Info

Product

Resources

About

Influence of solvent and salt on kinetics and equilibrium of esterification reactions

Cited by 8 publications

References 43 publications

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

Activity‐Based Models to Predict Kinetics of Levulinic Acid Esterification

Carboxylation of Acetylene without Salt Waste: Green Synthesis of C4 Chemicals Enabled by a CO2‐Pressure Induced Acidity Switch

Salzabfall‐freie Carboxylierung von Acetylen: Grüne Synthese von C4‐Chemikalien durch einen CO2‐Druck‐induzierten Aciditätsswitch

Contact Info

Product

Resources

About

Carboxylation of Acetylene without Salt Waste: Green Synthesis of C₄ Chemicals Enabled by a CO₂‐Pressure Induced Acidity Switch

Salzabfall‐freie Carboxylierung von Acetylen: Grüne Synthese von C₄‐Chemikalien durch einen CO₂‐Druck‐induzierten Aciditätsswitch