Kinetic studies in a batch reactor using ion exchange resin catalysts for oxygenates production: Role of mass transfer mechanisms

Optimization of the Production of 1,1-Diethoxybutane by Simulated Moving Bed Reactor

Simulated moving bed technology is applied in the field of pharmaceutical, petrochemical and fine chemistry. It shows capability in separating multicomponent mixtures up to high purities. In this work, an attempt was made to optimize the production of 1,1-diethoxybutane (DEB), using the simulated moving bed technology. A fixed bed model is made with good agreement with experimental results. This fixed bed model was expanded to a simulated moving bed model. This model was used to determine the optimum conditions regarding the switching time and flowrates in each section. From this model, the optimum switching time was found to be 2.4 min, and the ratio of liquid flowrate over the solid flowrate in Section 1Section 2Section 3 and Section 4 of the SMBR was found to be 4.24, 1.77, 3.03 and 1.35, respectively. Under those conditions, the productivity was 19.8 kg DEB per liter of adsorbent per day, and the desorbent consumption was 6.1 L of ethanol per kg of DEB. The results were obtained with a minimum purity of the extract and raffinate of 97%.

Kinetic Study on Esterification of Acetic Acid with Isopropyl Alcohol Catalyzed by Ion Exchange Resin

Esterification kinetics on acetic acid with isopropyl alcohol was studied in an intensified fixed bed reactor at 333-353 K with Amberlyst 36 Wet. The effects of volume flow rate, molar ratio of reactants, catalyst loading, and operating temperature were investigated and optimized. The method of UNIFAC was applied to calculate the activity coefficient of each component for correcting the nonideality of the solution. Reaction enthalpy, entropy, and Gibbs free energy were calculated in different cases. The pseudohomogeneous model, Eley-Rideal model, and Langmuir-Hinshelwood-Hougen-Watson model were used to establish kinetic equations of the reaction conducted in the IFBR. It was proved that the LHHW model can accurately describe the esterification kinetics in the intensified fixed bed reactor.

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.

Analysis of recycled poly (styrene-co-butadiene) sulfonation: a new approach in solid catalysts for biodiesel production

The disposal of solid waste is a serious problem worldwide that is made worse in developing countries due to inadequate planning and unsustainable solid waste management. In Mexico, only 2% of total urban solid waste is recycled. One non-recyclable material is poly (styrene-co-butadiene), which is commonly used in consumer products (like components of appliances and toys), in the automotive industry (in instrument panels) and in food services (e.g. hot and cold drinking cups and glasses). In this paper, a lab-scale strategy is proposed for recycling poly (styrene-co-butadiene) waste by sulfonation with fuming sulfuric acid. Tests of the sulfonation strategy were carried out at various reaction conditions. The results show that 75°C and 2.5 h are the operating conditions that maximize the sulfonation level expressed as number of acid sites. The modified resin is tested as a heterogeneous catalyst in the first step (known as esterification) of biodiesel production from a mixture containing tallow fat and canola oil with 59% of free fatty acids. The preliminary results show that esterification can reach 91% conversion in the presence of the sulfonated polymeric catalyst compared with 67% conversion when the reaction is performed without catalyst.