In this work, the main results of a thermodynamic and kinetic study of glycerol ketalization to produce solketal in the presence of a solvent are presented. A catalyst and a solvent screening was carried out leading to the selection of Amberlyst-35 ion-exchange resin and ethanol as the most suitable materials for this reaction. A parametric study allowed one to determine reaction equilibrium and kinetic parameters in a batch reactor in the absence of external mass-transfer limitations. Regarding reaction thermodynamic equilibrium, a standard enthalpy of −20.1 ± 1.1 kJ mol–1 and a Gibbs free energy of 1.4 ± 0.3 kJ mol–1 were obtained. Reaction kinetics was studied assuming different reaction rate laws to fit the experimental data obtained: Pseudo-Homogeneous (PH), Langmuir–Hinshelwood–Hougen–Watson (LHHW), and Eley–Rideal (ER). The experimental results revealed that the reaction kinetics behavior could be accurately described by the LHHW reaction rate law, considering the presence of internal mass-transfer resistances. The activation energy for the overall reaction was found to be 69.0 ± 6.6 kJ mol–1.

Biodiesel production has been generating increasing amounts of glycerol as byproduct, therefore effective strategies are required to convert it into valuable chemicals to enhance the sustainability of the biodiesel production chain. In this work, solketal was synthesized by reacting glycerol with acetone (in the presence of ethanol) in a fixed bed adsorptive reactor packed with Amberlyst-35. Additionally, adsorption equilibrium isotherms for all the compounds of the process were determined at 313 K through a frontal analysis methodology, and the results were fitted through a competitive multicomponent Langmuir model. It was possible to conclude that water was the most adsorbed compound while solketal was the least. The potential for implementation of sorptionenhanced reactive processes was experimentally demonstrated since the conversion values transitorily attained during the solketal synthesis process were approximately 30% above the equilibrium values. Finally, all the experimental results were accompanied by numerical simulation using a comprehensive mathematical model that was able to accurately describe the results.

The catalytic water–gas‐shift (WGS) reaction into hydrogen and carbon dioxide was investigated using a commercial nickel reformer catalyst. The effects of temperature, flow rate, and catalyst nature on the course of reaction were evaluated. Hydrogen and carbon dioxide were generated in the temperature range between 125 and 475 °C. A reaction scheme was used to explain the formation of methane. The WGS reaction and the methanation reaction (MTN) were used to calculate the equilibrium composition at these conditions. A commercial hydrotalcite‐like sorbent arranged in a multilayer pattern of catalyst plus sorbent was used for carbon dioxide capture to enhance the WGS reaction. The performance of the catalyst was assessed by comparing the measured conversions, hydrogen yields, and selectivities at steady‐state conditions with equilibrium values and with selected results reported recently, as well as conversions, hydrogen yields, and selectivities during the transient period as the hybrid system consisting of catalyst plus sorbent is arranged in a multilayer pattern system. The multilayer pattern system consisting of catalyst plus sorbent can easily overcome the thermodynamic restrictions of the WGS reaction at an operating temperature of 400 °C because of the enhanced sorption effect during the reaction process. In addition, lower flow rate regimes, and higher pressures and steam/carbon ratios increase the initial breakthrough period. This sorption‐enhanced technique makes the use of Ni‐based catalysts for the WGS reaction attractive, and suitable for the adjustment of the hydrogen ratio in synthesis gas streams.

Development of stable solid adsorbent in pellet form is of importance for CO 2 /H 2 separation at elevated temperature (250−450°C). This study provides a novel synthesis method by adding K 2 CO 3 solution into alumina sol soaked MgAl-layered double hydroxide paste. The delay time of K 2 CO 3 addition is studied to demonstrate that the formation of Kpromoted γ-alumina is facilitated by an immediate addition. Extruded adsorbent of higher CO 2 capacity (0.65 mmol/g) and radial crushing strength (75.6 N per pellet) is obtained. The existing crystalline phase of obtained adsorbent is screened by X-ray diffraction. The adsorption capacity and adsorption kinetics of the developed adsorbent is characterized by a thermogravimetric analyzer in terms of calcination temperature of both dominant constituent materials, MG63 hydrotacite, and K-promoted pseudo boehmite. Crystal transit temperatures of the constituents are considered in selecting the optimal calcinations temperature. The adsorbent pellets, pretreated with the optimal parameters studied, are packed in a fixed-bed to test breakthrough curves of CO 2 , consistent dynamic capacity compared to that of thermogravimetric testing data were obtained. Results of multicycle CO 2 adsorption and desorption, steam sweeping, pressure change, and wear tests prove the stability of the adsorbent both in CO 2 capacity and mechanical strength.

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