Synthesis and Characterization of TiO2/SiO2 Monoliths as Photocatalysts on Methanol Oxidation

Photocatalytic materials based on silica-titania (SiO2-TiO2) were synthesized by sol-gel and dip-coating method. TEOS and titanium butoxide were used as precursors of the silica-titania, respectively. A thin film with anatase phase was obtained on the surface of the support. The effect of variables as dispersion mechanism, immersion time, and number of treatment cycles were studied. The materials were characterized using X-ray diffraction, scanning electron microscopy, energy dispersion scanning, and N2 adsorption-desorption. The highest crystallinity of TiO2 on silica, high specific surface area in TiO2-SiO2 materials, and thin film formation were obtained by using a stirring plate and minimum immersion time. The so synthesized catalyst allowed the production of formaldehyde from the photocatalyzed methanol oxidation in a packed-bed reactor

Advanced Oxidation Processes: Ozonation and Fenton Processes Applied to the Removal of Pharmaceuticals

This chapter aims to present the fundamentals, important variables, and pharmaceuticals removed by ozonation and Fenton, which are only two of the current existing advanced oxidation processes. Some toxicological information regarding pharmaceuticals oxidized by ozonation is also included. Some strategies to improve such processes, like adding a catalyst, light, or electrical current, are also analyzed. Thus, this chapter intends to present general but fundamental aspects of the aforementioned processes

Advanced Oxidation Processes II: Removal of Pharmaceuticals by Photocatalysis

In this chapter, basic concepts of advanced oxidation processes (AOP) are cited, such as photolysis, photocatalysis, and semiconductors used as photocatalysts. This is important since the wastewater pollution with drugs, coming from domestic use, hospitals, and industry is not only an environmental problem but social too. Pharmaceutical case study is shown to exemplify the photocatalytic degradation of different drugs contained in wastewater taken directly from some currents in the pharmaceutical industry, such as diclofenac, acetaminophen, naproxen, and ibuprofen, using modified TiO2 catalysts with different tin contents.CONACy

Catálisis en el Centro Conjunto de Investigación en Química Sustentable, uaem-unam*

Describimos aquí las actividades de investigación en el área de catálisis realizadas por algunas investigadoras de la Facultad de Química de la Universidad Autónoma del Estado de México, adscritas al Centro Conjunto de Investigación en Química Sustentable, uaem-unam. Se incluyen las líneas de investigación que desarrollan, las contribuciones que han generado y los logros en este campo obtenidos en los últimos años. También se presenta información sobre la infraestructura con que se cuenta en el cciqs y en la Facultad de Química para llevar a cabo investigación sobre catálisis; la importancia que tienen los trabajos de colaboración nacional e internacional, así como, la formación de recursos humanos altamente especializados en esta área. Por último, presentamos las perspectivas de investigación y desarrollo planteadas para el campo de la catálisis

Biodiesel production as an alternative to reduce the environmental impact of University food courts

The objective of this work was to assess the environmental impacts of producing biodiesel by heterogeneous and homogeneous catalysis. The raw material for the process was the waste cooking oil (WCO) generated at 27 food courts of Autonomous University of the State of Mexico. The study was conducted by applying Life Cycle Assessment methodology and the environmental impacts were calculated with the SimaPro 9.1.0.11 PhD software with the Ecoinvent database. The method was CMLIA base line C3.06/EU25. The assessed impact categories were: Abiotic Depletion Potential (ADP, elements), Abiotic Depletion Potential (ADP, fossil fuels), Global Warming Potential (100 years) (GWP), Ozone Layer Depletion (ODP), Human Toxicity (HT), Freshwater Aquatic Ecotoxicity (FWAE), Marine Aquatic Ecotoxicity (MAE), Terrestrial Ecotoxicity (TE), Photochemical Oxidation (PO), Acidification (A) and Eutrophication (E). In addition, end point environmental indicators were also calculated (Ecosystems Quality, Human Health Damage and Resources Availability) by the method ReCiPe 2016 Endpoint (H) V1.04 / World (2010) H/A. The system boundary enclosed three main stages, WCO collection, pre-treatment and reaction (to produce biodiesel). It was concluded that the reaction stage is the one with the highest environmental impact. In this sense, the highest impact categories were ADP (fossil fuels) (105.56 MJ), GWP (8.91 kg CO2 eq) and MAE (2387.89 kg 1, 4-DB eq). Nevertheless, it was also found that the GWP for the heterogeneous process is 82.52 % lower than that calculated for the homogeneous process. In addition, the human health damage of the homogeneous process is 1.77 points and is higher than the observed with the heterogeneous process.UAEMEX 5083/REDP202 UAEMEX 6219/2020CIB CONACYT SCHOLARSHIP 36063

Bifunctional catalysts applied to produce biodiesel from waste cooking oil

This work aims to present the analysis of the catalytic performance of Fe2O3/CaO as a bifunctional catalyst in the production of biodiesel from waste cooking oil. The clamshell was used as a source of calcium oxide by calcination. The catalyst was characterized by Thermogravimetric analysis and Differential scanning calorimetry (TGA-DSC), X-ray diffraction (XRD) and Inductively coupled plasma atomic emission spectroscopy (ICP-AES). The catalytic tests were conducted at 55  C, the methanol:oil ratio was 12:1, amount of catalyst of 6%wt and reaction time of 5 h. The content of methyl esters in the produced biodiesel was >98% and was found to fulfill the specifications of European Norm UNE-EN 14214.Proyecto 6218/2020 CIB UAEMex CONACYT. Beca de estudios de posgrado (1000624) Estancia de investigación especializado Comecyt-EdoMex (EESP2021-0029

Auditoría financiera a la Compañía Constructora CONSTROENMA Cía. Ltda. periodo 2014

La presente investigación tiene por objetivo, realizar una auditoría financiera a la compañía constructora CONSTROENMA Cía. Ltda., período 2014, para la determinación de la razonabilidad de los Estados Financieros, es una institución de derecho privado, creada en el 2010, que se dedica a la construcción, ubicada en la provincia del Tena, ha venido presentado varios problemas originados de la falta de un archivo ordenado de documentos y el faltante de declaración a organismos de control como el IESS. Se aplicó el tipo de investigación el descriptivo, con el método inductivo deductivo y técnicos e instrumentos que apoyaron en el desarrollo de la propuesta. Para el desarrollo de la investigación se utilizó el estado de resultados y además las fases de la auditoría, en la primera se revisaron las siguientes cuentas obteniendo como resultado la determinación de las cuentas en base a la materialidad que fueron bancos, cuentas por cobrar, propiedad planta y equipos, cuentas por pagar, ventas y gastos sueldos y salarios, obteniendo los siguientes hallazgos; incorrecto registro de las depreciaciones de los activos fijos y también no se registró la totalidad de los gastos sueldos y salarios, dando un nivel de confianza global del 69.71%.This research aims to audit financial to the construction company CONSTROEMA Construction Company Ltda., period 2014, for the determination of the reasonableness of the financial statements, is an institution of law private, created in 2010, dedicated to building, located in Tena Province has been presenting various problems caused the lack of a file documents and the missing statement instructed agencies control as the IESS. The type of research applied was descriptive, the inductive-deductive method and technical instruments that supported the development of the proposal. The statement of income was used for the development of research and also phases of the audit, the first reviewed the following accounts resulting in the determination of the accounts based on the materiality that were banks. Accounts receivable, property, plant and equipment, accounts payable, sales and expenses, salaries and wages, obtaining the following findings; incorrect registration of the depreciation of fixed assets and also not registered all expenses wages and salaries, giving a level of global confidence from 69.71%

Comparative Study of Quick Lime and CaO as Catalysts of Safflower Oil Transesterification

This work aimed to contrast the performance of quicklime and CaO reagent grade as heterogeneous catalysts for the safflower oil transesterification reaction. Quicklime was characterized by TGA analysis, XRD, atomic absorption, nitrogen physisorption and by Hammett method. In the safflower transesterification reaction, four main variables were studied: addition reagents order, reagents dosage, type of catalyst and methanol-oil molar ratio. The addition reagents order was not found to be determinant on time for reaching equilibrium or maximum methyl esters yield. On the contrary, reagents dosage was found to negatively affect reaction rate and methyl esters yield. It was found that quicklime performs better than CaO and this was ascribed to an increased basicity found in the former. From the results can also be inferred that the use of quicklime as catalyst of the transesterification reaction allows the decrease of the process cost by reducing both, the reaction time and the required amount of alcohol

Absorption and reaction of CO2 in capillaries

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 increases when the temperature decreases, while the CO2 absorption in NaOH solutions increases directly with temperature. By means of the Ha number, it was concluded that the mass transfer controlled the absorption process when usingalkaline solutions.CONACYT SCHOLARSHIP (239954) CONACYT Project No. 269093 UAEMEX project 6235/2020CI