Cation-Exchange Resin Catalyzed Ketalization Reaction of Cyclohexanone with 1,4-Butanediol: Thermodynamics and Kinetics

Thermodynamic and Kinetic Study on the Catalysis of Isoamyl Acetate by a Cation-Exchange Resin in an Intensified Fixed-Bed Reactor

Kinetics and thermodynamics of esterification by a cation-exchange resin in an intensified fixed-bed reactor was studied systematically. The resin type, catalyst loading, volume flow rate, initial molar ratio, temperature, and catalyst reusability were studied and optimized. The nonideality of the reaction system was corrected by the UNIFAC group contribution method. The Δ_r H ⁰, Δ_r S ⁰, and Δ_r G ⁰ of the reaction were acquired by two methods. The pseudo-homogeneous (PH) model and the Langmuir-Hinshelwood-Hougen-Watson (LHHW) model were adopted to simulate the kinetic process. The result indicated that the LHHW model was better suited to simulate the kinetic process than the PH model.

B-SBA-16 encaged functional tungstosilicic acid type ionic liquids to catalyze the ketal reaction

There is special significance to composite catalysts using SBA-16 nano-cages as carriers in the acid catalysis field. A method for embedding boron atoms onto SBA-16 to increase acidic sites and enhance the acidity of the nano-cages was described. The tungstosilicic acid type ionic liquid (SWIL) was encaged into B-SBA-16 acidic nano-cages to obtain various composite catalysts. The acidic nano-cages and composite catalysts were characterized by FT-IR, TG/DSC, SAXD, BET, SEM, TEM, XPS and 1H NMR analyses. Research confirmed that boron was embedded onto the SBA-16 nano-cages in varying proportions and the obtained B-SBA-16 acidic nano-cages still maintained a high degree of pore ordering. The SWIL was successfully encapsulated into the acidic nano-cages via the immersion method. The cage-encapsulated tungstosilicic acid type ionic liquid catalysts SWIL/B(n)-SBA-16 were applied to catalyze the ketal reaction of cyclohexanone (CYC) with ethylene glycol (EG). The results showed that the conversion of CYC could reach 92.01% along with the yield of cyclohexanone ethylene glycol ketal (CGK) of 83.87% under ideal conditions. The CYC conversion was still nearly 86.86% and the CGK yield was 69.50% even after 8 times of continuous reuse.

Green Production of Glycerol Ketals with a Clay-Based Heterogeneous Acid Catalyst

Glycerol remains a bottleneck for the biodiesel industry as well as an opportunity from the biorefinery perspective, having a notable reactivity as a platform chemical. In particular, glycerol ketals can be envisaged as oxygenates for fuel formulation. In this study, we have focused on the green synthesis of glycerol ketals by reacting glycerol with acyclic (acetone, butanone) and cyclic (cyclohexanone) ketones in the presence of an acid activated clay Tunisian AC in homogeneous systems under quasi-solventless conditions. These reactions were followed by on-line Fourier Transform Infrared Spectroscopy (FTIR) (namely, ReactIR 10). Firstly, the contacting time was selected studying the activity, stability and chemical characteristics of a set of catalysts. The 1-h activated clay AC was further characterized by X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electronic Microscopy with Energy Dispersive Spectroscopy (SEM/EDS). Finally, the effect of the main operational variables (catalyst concentration, reagents molar ratio, time and temperature) were checked and we reflected on adequate second-order kinetic models with partial first-order deactivation.

Synthesis and Kinetics of the N-(2-Methyl-6-ethyl phenyl)-1-methoxypropyl-2-imine Schiff Base Catalyzed by NKC-9 Cation Exchange Resin

The kinetics of condensation reaction of methoxyacetone with 2-methyl-6-ethyl aniline catalyzed by NKC-9 cation exchange resin was studied for the first time. The reaction temperature of Schiff base synthesis was determined in the range of 367.15 to 401.15 K by the batch experiments, and influences of reactant molar ratio, temperature, catalyst dosage, and particle size on the ultimate conversion were also studied. The dynamic data were used to be relevant with PH, ER(1), ER(2), and Langmuir Hinshelwood Hougen Watson homogeneity models. Model parameters, including reaction equilibrium constants, activation energy, enthalpy change, entropy change, and rate constants, were solved. The accuracy of the model was validated by means of both experimental proofs and standard deviation between the predicted and experimental data. Finally, a series of characterization tests such as Fourier transform infrared spectroscopy, X-ray diffraction, and polarizing microscopy were performed to investigate the structure and properties of NKC-9.