Methanol to gasoline (MTG): Parametric study and validation of the process in a two-zone fluidized bed reactor (TZFBR)

Methanol to Gasoline (MTG) process transforms methanol to hydrocarbons within the boiling point range of gasoline. The result is a wide spectrum of products (olefins, paraffins, aromatics and naphthenics, among others), with the total conversion of methanol to hydrocarbons and water. Catalyst deactivation by coke is a main problem in this process. This work aims to determine the feasibility of carrying out the production of gasoline from methanol in a two-zone fluidized bed reactor (TZFBR). The hypothesis is that the formation of carbonaceous deposits (coke) on the catalyst particles can be counteracted by its combustion in the regeneration zone that this novel reactor presents, thus achieving stable and continuous operation. In this way, both processes (reaction and regeneration) would be being carried out simultaneously in the same reactor (process intensification). The comparison of results between a conventional fluidized bed reactor and a TZFBR shows that the second one actually provides a better stability over time

Methanol to Gasoline (MTG): preparation, characterization and testing of HZSM-5 zeolite-based catalysts to be used in a fluidized bed reactor

The preparation of catalysts suitable for MTG processes in a fluidized bed reactor has been studied with emphasis on improving the textural, physico-chemical, morphological, structural and mechanical properties. A mixture of HZSM-5 zeolite (active material), boehmite or bentonite (binder) and alumina (inert filler) was used to prepare different catalysts. After preparation, characterization by physical adsorption of N2, XRF, XRD and SEM-EDX techniques was carried out. The screening of catalysts was performed in a fluidized bed reactor. The distribution of products was very similar in all cases, with the yield of light hydrocarbons always being higher than that of gasoline. Among the catalysts tested, the one containing boehmite as a binder (HZ_Boeh) was found as the most appropriate due to its high mechanical strength, high yield to aromatics and lower yield to durene

Infrared sensor-based temperature control for domestic induction cooktops

In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented

Dry reforming of biogas in fluidized bed: Process intensification

Biogas is a renewable resource obtained mainly from the anaerobic fermentation of agro-industrial and anthropogenic residues. The production of hydrogen by dry reforming of methane represents a potential application for this renewable energy carrier. This could play a positive contribution towards meeting the challenge of providing a global supply of energetically sustainable and environmentally friendly energy. This work combines a catalytic reaction, a separation and the catalyst regeneration in a single reactor. To this end, a two zone fluidized bed reactor (TZFBR) with hydrogen selective membranes has been employed (TZFBR + MB). The operating conditions for the process of dry reforming of biogas have been optimized experimentally, both in TZFBR and TZFBR + MB. Several catalysts were prepared (Ni/Al2O3, Ni–Ce/Al2O3, Ni–Co/Al2O3), characterized and tested in reactions in both TZFBR and in TZFBR + MB. Finally, the influence of using oxygen or carbon dioxide as regenerating gases in the process has been studied. Experimental results show the feasibility of using CO2 for in situ catalyst regeneration, avoiding the potential problems associated with the use of O2

Preliminary study on the feasibility of using a zeolite A membrane in a membrane reactor for methanol production

The permeation of a mixture containing H2, CO2 and water through a zeolite membrane was studied under several operating conditions. The aim was to obtain insight on the feasibility of using such membrane in a zeolite membrane reactor for CO2 hydrogenation to methanol. The effects of total pressure (100–270 kPa), water partial pressure (10–18 kPa) and temperature (160–260 °C) were studied. Promising water-permanent gas separation factors were obtained up to 240 °C. A surprisingly high water partial pressure was found in the permeate in some cases, which is explained by the radial temperature gradient in the experimental system. The good capability of this zeolite A membrane to selectively separate water vapor makes it a promising material for its use in a zeolite membrane reactor

Aromatización de metano sobre Mo/HZSM-5/bentonita: Reactor de lecho fluidizado convencional frente a reactor de lecho fluidizado de dos zonas

Se ha realizado la transformación de metano a productos aromáticos utilizando un catalizador de Mo/HZSM-5/bentonita. Este proceso tiene el inconveniente de la desactivación del catalizador por la deposición de coque. En este trabajo se propone la configuración de reactor de lecho fluidizado de dos zonas (RLFDZ) para eliminar este inconveniente y permitir la operación en continuo

Methane aromatization in a fluidized bed reactor: Parametric study

Methane aromatization is a promising technology for the transformation of natural gas into liquid products, but suffers from the problem of catalyst deactivation by coke. A two-zone fluidized bed reactor has been proposed as a tool to counteract the catalyst deactivation, by providing continuous catalyst regeneration in the same vessel where the main reaction is carried out. This work shows the effect of the main operating conditions (carburization temperature, reaction temperature, carburization time, nature of regenerating agent and feed flow and height of the hydrocarbon entry point). Optimal reduction time and temperature were 1 h and 350°C. Best conversion and selectivity were achieved at 700°C without catalyst deactivation in the TZFBR

Regeneración del catalizador con CO2 en la reacción de deshidrogenación de etilbenceno

En este trabajo se ha estudiado el papel como oxidante del CO2 en la reacción catalítica de deshidrogenación de etilbenceno para producir estireno. Se diseñaron una serie de experimentos partiendo de distintos estados de oxidación del catalizador variando los parámetros de temperatura y presión de vapor

Caracterización de catalizadores multifuncionales basados en Cu/Zn/Zr (CZZ) para la producción de dimetil éter (DME) en reactor de lecho fluidizadp

Debido a la gran problemática ambiental actual es necesario desarrollar combustibles sintéticos con emisiones neutras de carbono. En este trabajo se ha realizado un estudio fluidodinámico de catalizadores multifuncionales basados en Cu/Zn/Zr para la reacción de hidrogenación de CO2 a DME en reactores de lecho fluidizado

The influence of external factors on bacteriophages—review

The ability of bacteriophages to survive under unfavorable conditions is highly diversified. We summarize the influence of different external physical and chemical factors, such as temperature, acidity, and ions, on phage persistence. The relationships between a phage’s morphology and its survival abilities suggested by some authors are also discussed. A better understanding of the complex problem of phage sensitivity to external factors may be useful not only for those interested in pharmaceutical and agricultural applications of bacteriophages, but also for others working with phages