Javier de J. Guadarrama

Biogas treatment by ashes from incineration processes

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.

Experimental Evaluation of Sulfur Dioxide Absorption in Water Using Structured Packing

An experimental study of hydrodynamic and mass transfer processes was carried out in an absorption column of 0.252 m diameter and 3.5 m of packed bed height developed by Mexican National Institute of Nuclear Research (ININ by its acronym in Spanish) of stainless steel gauze corrugated sheet packing by means of SO2-air-water systems. The experiments results include pressure drop, flows capacity, liquid hold-up, SO2 composition, and global mass transfer coefficient and mass transfer unit height by mass transfer generalized performance model in order to know the relationship between two-phase countercurrent flow and the geometry of packed bed. Experimental results at loading regimen are reported as well as model predictions. The average deviation between the measured values and the predicted values is % of 48-data-point absorption test. The development of structured packing has allowed greater efficiency of absorption and lower pressure drop to reduce energy consumption. In practice, the designs of equipment containing structured packings are based on approximations of manufacturer recommendations.

A Study Numerical Simulation of Post Combustion CO2 Capture Process

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

CO2 Capture for Atmosphere Pollution Reduction

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.

Exergy Analysis of the Sequestration of CO2 Emissions

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

Thermodynamic Analysis of the CO2 Gas Removal Process

The present paper describes the thermodynamic analysis of the carbon dioxide (CO2 ) gas removal process in two separated columns with absorption/stripping sections respectively. This process is characterized as mass transfer enhanced by chemical reaction, in which the presence of an alkanolamine enhances the solubility of an acid gas in the aqueous phase at a constant value of the equilibrium partial pressure. 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. Furthermore, they point out where the irreversibilities of the process are located, and provide a generalized discussion from the successful application of the technique.Copyright

Procedimiento para el Cálculo del Area Geométrica de Empaques Estructurados

En este trabajo se presenta un procedimiento para determinar el area geometrica de contactores liquido gas de alta eficiencia denominados empaques estructurados, construidos de malla de alambre del numero 60: ININ60 y Sulzer BX. El area total que se ofrece para el contacto liquido-gas por unidad de volumen empacado se determina multiplicando el perimetro de la circunferencia de los alambres por su longitud, y por el numero de hilos, restandole las areas de contacto entre los alambres. La desviacion 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 util para su aplicacion para este tipo de material.

Thermodynamic Analysis of the First Stage of Heavy Water Production

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

Capital and Operating Cost as Driving Forces of the First Stage of Heavy Water Production

The present paper describes the behavior of the capital and operating cost as driving forces for the design of the first stage of enrichment of heavy water production by the Girdler Sulfide (GS) process. A very useful procedure for analyzing a process or control system is by means of the Second Law of Thermodynamics. Determining where the irreversibilities of a process or control systems are generally indicates where the greatest improvements can be made, particularly as they relate to operating cost. Thermodynamic analyses based on the concepts of irreversible entropy increase have frequently been suggested as pointers to sources of inefficiency in chemical processes. Furthermore, this study shows a generalized discussion of the cost with respect to the optimization parameters, it points out where the irreversibilities of the process are located, and provides a generalized discussion from the successful application of the technique.Copyright

Energy Savings and Pollution Reduction by Coupling a Three-Kiln Brick Production System for the Construction Industry

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