Search

The present work is a comparative evaluation on CO2 capture process post-combustion by chemical absorption with alkanolamines, of three Mexican power plants, each one with a different method of operation and fossil fuel used: natural gas type, gas turbine type, and of coal type. They were compared with one another to determine which one has the largest CO2 capture flow. This comparison was done through an experimental facility with mainly absorption column of: 0.30 m diameter, 3.5 m packed height, structured packings, and 30 % weight solvent concentrations of monoethanolamine. The experimental data let to develop numerical evaluations through computer simulation on steady state of the integrated plants. The results show that the highest CO2 capture flow was obtained from the coal-fired power plant with 3.03 t/d, followed by natural gas type with 1.88 t/d, and the lowest one was the gas turbine type with 0.80 t/d.

The burning of combustible material that produces emissions released to the atmosphere results in unfavorable climate change due to emissions of CO2, NO x , and acid rain by SO x , endangering the health of the population. The treatment of combustion gases by means of a packed absorption column with a high-efficiency liquid–gas contactor material reduces pollutant emissions to the atmosphere, where combustion gases make contact with aqueous amine solution of mono ethanol amine (MEA), using different structured packing materials which can be metallic, polymeric, or ceramic. The objective of this work is to study which one of these three types of materials of gas–liquid contactors presents the lowest deterioration in the presence of combustion gases flowing countercurrent to MEA. The materials were evaluated according to the Standard Test Methods ASTM G31-2004 for corrosion testing, ASTM E8-1998 for tension testing, ASTM E384-1990 for microhardness testing, ASTM G5-1999 for potentiodynamic and potentiostatic testing, and the procedure of NRF-194 PEMEX-2007. The properties studied were the tensile strengths, the hardness values, and the elastic moduli, before and after structured packing materials made contact with combustion gases in MEA aqueous solution. The results showed that in acidic and basic mediums, the metallic material was the most resistant to abrasion; it has the highest tensile strength, and presents more resistance during the stress test. The hardness results for the materials were metallic: 190 KH, polymeric: 20 KH, and ceramic: 700KH. The respective corrosion resistances in the presence of MEA were 1.63 × 10−3, 3.76 × 10−3, and 1.42 × 10−2 mm/year.

This paper presents the characterization of ashes generated from different incineration processes, such as (a) coupled kilns, (b) conventional kiln, (c) wood, and (d) fly and bottom of Petacalco power plant, in order to set which is the best one for the purification of biogas from landfill. The techniques employed for the characterization were scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The ashes from these sources were analysed through their microstructural properties and features such as the efficiency of carbon dioxide reduction due to chemical reaction with the calcium oxide present in the ashes. Calcium carbonate mineral was obtained as a highly stable and insoluble salt. The results indicate that the ash from wood is the most appropriate to reduce the carbon dioxide due to its high calcium content. Dry fly ash from Petacalco power plant has the ability to carry out a process of carbonation according to the samples analyzed. It was noted that elements such as aluminium, sodium, potassium, and magnesium led to the formation of some other mineral species in the ash resulting from incineration processes.

Amine absorption technology, in particular that based on the Monoethanolamine (MEA) process, is considered to be viable for low pressure flue gas CO2 capture because of the MEA- CO2 fast reaction rate. MEA absorption processes are associated with high capital and operating cost because a significant amount of energy is required for solvent regeneration and severe operating problems are present such as corrosion and solvent loss and degradation. The overall objective of this study is to evaluate the feasibility of obtaining the heat required for amine absorption for a particular recovery of carbon dioxide. Comparisons among cases were performed to determine the best operating conditions for CO2 capture. An analysis of the lean load and recovery percentage were carried out as well as the different absorber and stripper combinations by using the chemical process simulator and focus a Central Electric in Mexico.

The thermodynamic analysis of the first stage of enrichment of heavy water production by the Girdler Sulfide (GS) process is described. Use of the Second Law of Thermodynamics as analysis tool allows a simple and useful procedure for the quantification of the transit energy in the process. Such thermodynamic analysis based on the concepts of irreversible entropy increase has frequently been suggested as pointers to sources of inefficiency in chemical processes. Furthermore, this study points out where the irreversibilities of the process are located, a generalized discussion of the cost with respect to the optimization parameters, and provides a generalized discussion from the successful application of the technique. © 2007 American Institute of Chemical Engineers AIChE J, 2007

Amine absorption technology, in particular that based on the Monoethanolamine (MEA) process, is considered to be viable for low pressure flue gas CO2 capture because of the MEA-CO2 fast reaction rate. MEA absorption processes are associated with high capital and operating cost because a significant amount of energy is required for solvent regeneration and severe operating problems are present such as corrosion and solvent loss and degradation. The overall objective of this study is to evaluate the feasibility of obtaining the heat required for amine absorption for a particular recovery of carbon dioxide. Comparisons among cases were performed to determine the best operating conditions for CO2 capture. An analysis of the lean loading and recovery percent were carried out as well as the different absorber and stripper combinations by using the chemical processes simulator.Copyright © 2009 by ASME

Carbon dioxide capture from flue gas using amine-based CO2 capture technology requires huge amounts of energy mostly in the form of heat. The overall objective of this study is to evaluate the feasibility of obtaining the heat required for amine absorption for a particular recovery of carbon dioxide for a given a set of equipment specifications and operating conditions from the process and to develop a model that simulates the removal of CO2 using Monoethanolamine (MEA) absorption from flue gas and design a process that will minimize the energy of CO2 capture with Aspen Plus™ will be used. A very useful procedure for analyzing a process is by means of the Second Law of Thermodynamics. Thermodynamic analyses based on the concepts of irreversible entropy increase have frequently been suggested as pointers to sources of inefficiency in chemical processes.Copyright © 2008 by ASME

Carbon dioxide is considered to be the major source of greenhouse gases responsible for global warming; man-made CO2 contributes approximately 63.5 % to all greenhouse gases. Efforts towards reducing greenhouse gas emissions have increased in the past few years, offering promising alternatives in power generation and better fuel efficiency. However, the incorporation of these new technologies to our daily lives represents a big challenge to be solved in the mid- to long-term, leaving separation and CO2 sequestration to be an immediate priority for researchers. CO2 capture and storage can support the transition of our fossil fuel based energy supply towards a sustainable energy system, based upon nuclear and renewable sources. Our present energy infrastructure will largely remain the same during this transition period. For example, electric power plants will be equipped with CO2 capture units, but will produce the same electricity, transported and distributed over the same grid. The first step in the CO2 capture and storage chain is to capture carbon in a high concentration. This can be done before or after combustion of the fuel. Capture is best carried out at large sources of emissions, such as power stations, refineries and other industrial complexes. There are several ways to capture CO2, some of the main methods are absorbents using solvents or solid sorbents, which have been used in industry for several years and seems to be the most feasible solution at this time; membranes have also become an interesting alternative and although extensive research is in progress, new materials for membranes have yet to be discovered. Other methods like pressure- and temperature-swing adsorption using various solid sorbents, cryogenic distillation and new emerging technologies show promising results in the bench testing scale. This report presents a comparison between these different methods.

The present paper describes the thermodynamic analysis of the first stage of enrichment of heavy water production by the Girdler Sulfide (GS) process. A very useful procedure for analyzing a proces is by means of the Second Law of Thermodynamics. Thermodynamic analyses based on the concept of irreversible entropy increase have frequently been suggested as pointers to sources of inefficiency in chemical processes. Furthermore, this study points out where the irreversibilities of the process are located, and provides a generalized discussion from the successful application of the technique.Copyright © 2006 by ASME

En este trabajo se presenta un procedimiento para determinar el área geométrica de contactores liquido gas de alta eficiencia denominados empaques estructurados, construidos de malla de alambre del numero 60: ININ60 y Sulzer BX. El área total que se ofrece para el contacto líquido-gas por unidad de volumen empacado se determina multiplicando el perímetro de la circunferencia de los alambres por su longitud, y por el número de hilos, restándole las áreas de contacto entre los alambres. La desviación promedio de los resultados con respecto a lo reportado en la literatura fue de 4.5%, lo que indica que el procedimiento es confiable y útil para su aplicación para este tipo de material. The paper presents the development of a procedure to determine the geometrical area of high efficiency liquid gas contactor named structured packing materials made of gauze (number 60) i.e., ININ60 and Sulzer BX. The total area available per packed volume for the gas-liquid contact is determined by multiplying the length of the circumference of the wires by its length, minus the wires contacting area. The average deviation between the presented results and previously reported is 4.5%. This procedure is reliable and useful for this type of material.

El objetivo del presente trabajo es ajustar un modelo hidrodinamico para columna empacada con empaque estructurado, partiendo de valores experimentales. Se comparan dos empaques, uno construido en el Instituto Nacional de Investigaciones Nucleares (ININ), de gasa de alambre de laton, y otro de la empresa Sulzer Ltda., de gasa de alambre de acero inoxidable. El modelo hidrodinamico se ajusto mediante la tecnica de minimos cuadrados con el metodo Levenberg-Marquardt para ecuaciones no lineales. Se obtuvieron las caidas de presion experimentales y teoricas determinadas por el modelo, asi como los parametros de ajuste del modelo tanto para el empaque ININ, como para el Sulzer BX. El empaque ININ mostro mayor caida de presion que el empaque Sulzer BX, debido a sus caracteristicas geometricas. Se concluye que con la determinacion de los parametros de ajuste del modelo, se puede definir los regimenes del flujo de columnas que empleen empaque estructurado ININ y Sulzer BX.

espanolEn este trabajo se muestra la operacion de un empaque estructurado construido en el Instituto Nacional de Investigaciones Nucleares (ININ), del tipo gasa de alambre y fabricado en laton. Los resultados experimentales son las caidas de presion generadas por el paso de los flujos gaseoso y liquido que cruzan el empaque, las retenciones volumetricas del liquido, los coeficientes volumetricos de transferencia de masa por el lado liquido y las alturas de unidades de transferencia de masa del liquido. Los resultados son comparados con los de el empaque estructurado comercial Sulzer BX, igualmente del tipo de gasa de alambre y construido en acero inoxidable,. Los resultados experimentales muestran que el empaque ININ es mas eficiente en la transferencia de masa, pero con mayor caida de presion, en comparacion con el empaque Sulzer BX, debido a las caracteristicas geometricas y al tipo de material de construccion. EnglishThis paper shows the performance of a structured packing of the gauze type and made out of brass, developed at the National Institute of Nuclear Research, Mexico (ININ). The experimental results are the pressure drop of the gas and liquid through the packing, the liquid volumetric holdups, the liquid-side volumetric mass transfer coefficients and the heights of liquid-side mass transfer unit. The results are compared with the commercial structured packing Sulzer BX, also of the gauze type and made out of stainless steel. The experimental results show that the ININ packing offers higher mass transfer efficiency but higher pressure drop than the Sulzer BX packing due to their geometric characteristics and the type of construction material.

Atmospheric pollution is one of the most important environmental problems, becoming a phenomenon that could reach levels of serious consequences with irreversible environmental impacts. In Mexico, like in several other countries, brick makers carry out brick production by burning mixtures of different heavy fuels. Because of the wide variety of fuels used it is necessary to determine what types of residual gases are generated, in order to propose remedial treatments in production or to introduce substitution technologies. These preventive actions need to be put in place in order to comply with the Ecological Balance and Environment Protection General Law. Brick kilns emit pollutant gases and particles that remain in the air causing a serious health hazard to the near-factory residents. Amongst these pollutants are carbon monoxide (CO), sulfur oxides (SOx ) and hydrocarbons. This paper presents the results of the analysis of a novel 3-kilns coupled system. This experimental analysis includes the determination of the combustion products for gases and particulate matter generated from the burning of the heavy fuels using Gas Chromatography and Scanning Electron Microscopy. Field data also allowed the determination of energy savings for this system, mainly due to the reduction of the consumption of fuel. Fortunately these results show a combined 30% energy savings and a reduction of pollutants and particle emissions.Copyright © 2004 by ASME

In order to determine the dimension of a separation column, hydrodynamic and mass transfer models are necessary to evaluate the pressure drop and the height of the global mass transfer unit, respectively. Those parameters are a function of the cross sectional area of the column. The present work evaluates the dependency of the pressure drop and height of the global transfer unit with respect to the cross sectional area of the column, using an absorption column with high efficiency structured packing, in order to recover SO2 in the form of NaHSO3 , as an example. An optimization was done applying Two Film model which is based on the number of global mass transfer units of both gas and liquid, involving the separation efficiency in terms of the height of a global transfer unit. Structured packing, geometrically heaped in a separation column, has been achieving wider acceptance in the separation processes due to their geometric characteristics that allow them to have greater efficiency in the separation processes. Three different structured packing were evaluated in this work. The results show how ININ packing is one of the packings does the best work having the highest separation efficiency because it has the lowest height of the global mass transfer unit and Mellapak packing has the largest capacity because it manages the largest liquid and gas flows. An analysis is done with respect to the pressure drop through the system for all packings considered, and a discussion is presented for each hydrodynamic and mass transfer parameter studied.Copyright © 2003 by ASME

The atmospheric contamination is a significant problem for the population of the big cities. This problem has its origin in the burning of heavy oil, that is carried out to liberate its energy content. Its use as a primary source of energy has high pollution effects in its process due to the formation and expulsion of gases and particles as a consequence of its combustion that contaminate the atmosphere. Although it has had enough relative elements of legal type relative to the contamination, specially atmospheric contamination, there is a lack of solutions adapted to the characteristics of the problem for each country. The present work quantifies the improvements in mass transfer, using absorption column with structured packing of high efficiency for the recovery of the SO2 , through the process of removal of SO2 in the form of CaSO3 . For such study, the hydrodynamic and mass transfer models are used to design the column, as well as to prove different packings (national production, denominated ININ in Mexico, SulzerBX, Mellapak and Raschig) to evaluate the separation efficiency. It is discussed that the ININ packing was one of the best of those tested because it has the highest separation efficiency.Copyright © 2002 by ASME

The expulsion of sulphur dioxide from hydrocarbon combustion can reach levels higher than accepted by the normative. In order to evaluate the efficiency of separation of SO2 by different packing systems constructed with materials such as metals or ceramics, the mass transfer and hydrodynamic parameters were evaluated. With the use of mass transfer model, the ININ packing showed higher separation efficiency with respect to Sulzer BX, Mellapak, and Raschig packing: 33.74%, 45.43% and 61.32%, respectively. These results were because the ININ packing has lower corrugation angles and narrower corrugated side than the others. The present work quantifies the improvements in mass transfer, like mass transfer volumetric coefficient and the height of the transfer global units in gas and liquid phase per each packing, using absorption columns with different gas flow managed: 5,000, 4,000 and 3,000 Nm³/h. The hydrodynamic model was used to design the column, as well as to determine the diameter or the cross area of the column per each packing. It is discussed that the ININ packing was one of the best of those tested because it has the highest separation efficiency with the least height of the transfer global units.