Transportadores sólidos de oxigênio a base de cobre para a tecnologia de recirculaçao química

Abstract

The CO2 emissions arising from the combustion of fossil fuels has been cited as the main cause of global warming. One way to avoid such emissions into the atmosphere is to capture and store CO2, which can be implemented in various ways, but many existing techniques require large amounts of energy, which increases the cost of the process. In this context, the technology for Chemical Looping Combustion (CLC) is a promising alternative in power generation with the ability to facilitate the capture and storage of this gas without large energy demands. The main advantage of this technology is to reduce damage to the environment with a combustion-free N2, which prevents the formation of compounds such as NOx and CO2 capture facilitates no additional separation. For this alternative technology is efficient, solid with high oxygen transfer capacity, high reactivity with fuel, low tendency to agglomeration and low fragmentation rate and friction should be used. Moreover, such solids should have low production costs, and are environmentally friendly and stable to be fluidizable several cycles of oxidation / reduction to high temperatures (Adanez, 2012). The TSO's based on copper have several advantages for use in technology CLC, such as high ability to transport oxygen are reactive and show good chemical stability, and is one of the cheapest that can be used for this process. The objective of this research is to define a methodology for the preparation of solid oxygen carriers (SOC) copper base to be used in the process of CLC methane. The SOC’s were prepared with composition of 10% copper in two steps, the first definition for and the method of preparation and the second stage solvent used to study the influence of additives on the support and the SOC. In the first step the support used was -Alumina and was added to 1% cerium to the support, 0,5 and 1% nickel to the SOC. In the second step, the SOC's were supported on -Alumina by methods wet impregnation by Rotavapor, humidity incipient and Spray Dryer, using two kinds of solvents: water and ethanol. The samples were characterized by the techniques of Ray Fluorescence-X (RFX), Specific Surface Area (SSA), Temperature Programmed Reduction (TPR), X-ray diffraction (XRD), and Reactivity in Chemistry recirculation process. Given the results, it is concluded that the most appropriate method to prepare solid carriers oxygen copper base is the Wet Impregnation Rotavapor by using water as a solvent and additives did not promote significant improvements.