CIERMMI Women in Science Engineering and Technology TXV
The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studi... more The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studied worldwide. The main purpose is to decrease emissions to the environment that are associated with global warming, as well as the creation of renewable and sustainable energy sources. In the aforementioned process, the absorption of CO2 is of paramount importance as well as the reactor where the CO2 conversion takes place. In this context, the objective of this chapter is to present and analyze the results of the CO2 absorption in alkaline solutions in capillary reactors. A hydrodynamic study is included in order to establish the operational window of liquid and gas velocities in order to achieve the Taylor flow regime. All experiments were conducted in a capillary reactor (dc = 3 mm). The studied variables were temperature, NaOH concentration (0-0.75 M) and capillary length (300 and 100 mm). It was found that the volumetric mass transfer coefficient of the absorption of CO2 in water in...
ABSTRACT This study evaluates the effect of adding electrochemical copper(II) ions into an ozonat... more ABSTRACT This study evaluates the effect of adding electrochemical copper(II) ions into an ozonation process for treating industrial wastewater. Combining the processes resulted in a synergy that enhanced the reduction of physicochemical parameters (COD, TOC, color, turbidity, Z-Potential, and conductivity). In only 15 minutes the integrated process reduced the COD by 83%, TOC by 78 %, color by 93%, turbidity by 77%, and conductivity by 27% at relatively low current density (12.5 mA cm−2). Thus, the combination of the electrochemical and ozonation processes noticeably improves wastewater quality, decreases the process time, and reduces the sludge production.
In the present study, glycerol was oxidized by photocatalysis to glyceraldehyde, formaldehyde, an... more In the present study, glycerol was oxidized by photocatalysis to glyceraldehyde, formaldehyde, and formic acid. Copper-doped TiO2 was synthesized by the evaporation-induced self-assembly approach and it was used as catalyst during the glycerol photo-oxidation reactions. The prepared mesoporous material exhibited high specific surface area (242 m2/g) and band gap energy reduction of 2.55 eV compared to pure titania (3.2 eV) by the synthesis method due to the presence of copper cations (Cu2+ identified by XPS). The catalyst showed only anatase crystalline phase with nanocrystals around 8 nm and irregular agglomerates below 100 μm. The selectivity and formation rate of the products were favored towards formaldehyde and glyceraldehyde. The variables studied were catalyst amount, reaction temperature, and initial glycerol concentration. The response surface analysis was used to evaluate the effect of the variables on the product’s concentration. The optimized conditions were 0.4 g/L cata...
Statistical analysis was applied to optimize the electrochemical mineralization of ibuprofen with... more Statistical analysis was applied to optimize the electrochemical mineralization of ibuprofen with two boron-doped diamond (BDD) electrodes in a continuous electrochemical flow reactor under recirculation batch mode. A central composite rotatable (CCR) experimental design was used to analyze the effect of initial pH (2.95–13.04), current intensity (2.66–4.34 A), and volumetric flow rate (0.16–1.84 L/min) and further optimized by response surface methodology (RSM) to obtain the maximum mineralization efficiency and the minimum specific energy consumption. A 91.6% mineralization efficiency (EM) of ibuprofen with a specific energy consumption (EC) of 4.36 KW h/g TOC within 7 h of treatment was achieved using the optimized operating parameters (pH0 = 12.29, I = 3.26 A, and Q of 1 L/min). Experimental results of RSM were fitted via a third-degree polynomial regression equation having the performance index determination coefficients (R2) of 0.8658 and 0.8468 for the EM and EC, respectively...
In this work, fluorinated and platinized TiO2 was evaluated in the glycerol oxidation. Fluorinati... more In this work, fluorinated and platinized TiO2 was evaluated in the glycerol oxidation. Fluorination led to increase the specific surface area of titania, and platinization treatment led to obtain the highest absorption in the visible region of the electromagnetic spectrum; thus, 0.5 wt.% Pt-F-TiO2 was the best catalyst in the obtention of highest yield and selectivity to glyceraldehyde (GAL). It was also found that 2wt.% of Pt content had a detrimental effect in the glycerol conversion. Fluorination and platinum addition led to modify the reaction mechanism and selectivity.
The 2nd International Online-Conference on Nanomaterials, 2020
In this work, catalysts based on TiO2 modified by fluorination and platinum addition were prepare... more In this work, catalysts based on TiO2 modified by fluorination and platinum addition were prepared and evaluated in glycerol oxidation. The materials were characterized by TEM, N2 physisorption, XRD, UV–Vis DRS, XRF and XPS. It was found that fluorination led to an increase in the surface area of TiO2, and by platinization treatment, it was possible to obtain a high absorption in the visible region of the electromagnetic spectrum. From these improved properties, 0.5 wt.% Pt-F-TiO2 was prepared as the best catalyst for the obtention of the highest yield and selectivity towards glyceraldehyde (GAL). It was also observed that the increase in Pt content had a detrimental effect on the effectiveness of fluorinated titania in the glycerol conversion. The fluorination and platinum addition modify some physicochemical properties of TiO2, thus also modifying the reaction mechanism and selectivity during glycerol oxidation.
In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol... more In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol (4-CP) degradation at lab and pilot scale is presented. It was found that, in the degradation of phenol, the performance of a coupled electro-oxidation/ozonation process is superior to that observed by a photo-Fenton process. Phenol removal rate was determined to be 0.83 mg L−1 min−1 for the coupled process while the removal rate for photo-Fenton process was only 0.52 mg L−1 min−1. Regarding 4-CP degradation, the complete disappearance of the molecule was achieved and the efficiency decreasing order was as follows: coupled electro-oxidation/ozonation > electro-Fenton-like process > photo-Fenton process > heterogeneous photocatalysis. Total organic carbon was completely removed by the coupled electro-oxidation/ozonation process. Also, it was found that oxalic acid is the most recalcitrant by-product and limits the mineralization degree attained by the technologies not applying o...
CIERMMI Women in Science Engineering and Technology TXV
The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studi... more The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studied worldwide. The main purpose is to decrease emissions to the environment that are associated with global warming, as well as the creation of renewable and sustainable energy sources. In the aforementioned process, the absorption of CO2 is of paramount importance as well as the reactor where the CO2 conversion takes place. In this context, the objective of this chapter is to present and analyze the results of the CO2 absorption in alkaline solutions in capillary reactors. A hydrodynamic study is included in order to establish the operational window of liquid and gas velocities in order to achieve the Taylor flow regime. All experiments were conducted in a capillary reactor (dc = 3 mm). The studied variables were temperature, NaOH concentration (0-0.75 M) and capillary length (300 and 100 mm). It was found that the volumetric mass transfer coefficient of the absorption of CO2 in water in...
ABSTRACT This study evaluates the effect of adding electrochemical copper(II) ions into an ozonat... more ABSTRACT This study evaluates the effect of adding electrochemical copper(II) ions into an ozonation process for treating industrial wastewater. Combining the processes resulted in a synergy that enhanced the reduction of physicochemical parameters (COD, TOC, color, turbidity, Z-Potential, and conductivity). In only 15 minutes the integrated process reduced the COD by 83%, TOC by 78 %, color by 93%, turbidity by 77%, and conductivity by 27% at relatively low current density (12.5 mA cm−2). Thus, the combination of the electrochemical and ozonation processes noticeably improves wastewater quality, decreases the process time, and reduces the sludge production.
In the present study, glycerol was oxidized by photocatalysis to glyceraldehyde, formaldehyde, an... more In the present study, glycerol was oxidized by photocatalysis to glyceraldehyde, formaldehyde, and formic acid. Copper-doped TiO2 was synthesized by the evaporation-induced self-assembly approach and it was used as catalyst during the glycerol photo-oxidation reactions. The prepared mesoporous material exhibited high specific surface area (242 m2/g) and band gap energy reduction of 2.55 eV compared to pure titania (3.2 eV) by the synthesis method due to the presence of copper cations (Cu2+ identified by XPS). The catalyst showed only anatase crystalline phase with nanocrystals around 8 nm and irregular agglomerates below 100 μm. The selectivity and formation rate of the products were favored towards formaldehyde and glyceraldehyde. The variables studied were catalyst amount, reaction temperature, and initial glycerol concentration. The response surface analysis was used to evaluate the effect of the variables on the product’s concentration. The optimized conditions were 0.4 g/L cata...
Statistical analysis was applied to optimize the electrochemical mineralization of ibuprofen with... more Statistical analysis was applied to optimize the electrochemical mineralization of ibuprofen with two boron-doped diamond (BDD) electrodes in a continuous electrochemical flow reactor under recirculation batch mode. A central composite rotatable (CCR) experimental design was used to analyze the effect of initial pH (2.95–13.04), current intensity (2.66–4.34 A), and volumetric flow rate (0.16–1.84 L/min) and further optimized by response surface methodology (RSM) to obtain the maximum mineralization efficiency and the minimum specific energy consumption. A 91.6% mineralization efficiency (EM) of ibuprofen with a specific energy consumption (EC) of 4.36 KW h/g TOC within 7 h of treatment was achieved using the optimized operating parameters (pH0 = 12.29, I = 3.26 A, and Q of 1 L/min). Experimental results of RSM were fitted via a third-degree polynomial regression equation having the performance index determination coefficients (R2) of 0.8658 and 0.8468 for the EM and EC, respectively...
In this work, fluorinated and platinized TiO2 was evaluated in the glycerol oxidation. Fluorinati... more In this work, fluorinated and platinized TiO2 was evaluated in the glycerol oxidation. Fluorination led to increase the specific surface area of titania, and platinization treatment led to obtain the highest absorption in the visible region of the electromagnetic spectrum; thus, 0.5 wt.% Pt-F-TiO2 was the best catalyst in the obtention of highest yield and selectivity to glyceraldehyde (GAL). It was also found that 2wt.% of Pt content had a detrimental effect in the glycerol conversion. Fluorination and platinum addition led to modify the reaction mechanism and selectivity.
The 2nd International Online-Conference on Nanomaterials, 2020
In this work, catalysts based on TiO2 modified by fluorination and platinum addition were prepare... more In this work, catalysts based on TiO2 modified by fluorination and platinum addition were prepared and evaluated in glycerol oxidation. The materials were characterized by TEM, N2 physisorption, XRD, UV–Vis DRS, XRF and XPS. It was found that fluorination led to an increase in the surface area of TiO2, and by platinization treatment, it was possible to obtain a high absorption in the visible region of the electromagnetic spectrum. From these improved properties, 0.5 wt.% Pt-F-TiO2 was prepared as the best catalyst for the obtention of the highest yield and selectivity towards glyceraldehyde (GAL). It was also observed that the increase in Pt content had a detrimental effect on the effectiveness of fluorinated titania in the glycerol conversion. The fluorination and platinum addition modify some physicochemical properties of TiO2, thus also modifying the reaction mechanism and selectivity during glycerol oxidation.
In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol... more In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol (4-CP) degradation at lab and pilot scale is presented. It was found that, in the degradation of phenol, the performance of a coupled electro-oxidation/ozonation process is superior to that observed by a photo-Fenton process. Phenol removal rate was determined to be 0.83 mg L−1 min−1 for the coupled process while the removal rate for photo-Fenton process was only 0.52 mg L−1 min−1. Regarding 4-CP degradation, the complete disappearance of the molecule was achieved and the efficiency decreasing order was as follows: coupled electro-oxidation/ozonation > electro-Fenton-like process > photo-Fenton process > heterogeneous photocatalysis. Total organic carbon was completely removed by the coupled electro-oxidation/ozonation process. Also, it was found that oxalic acid is the most recalcitrant by-product and limits the mineralization degree attained by the technologies not applying o...
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