Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Sustainable use of Aloe vera oil against corrosion in copper-containing refrigeration systems
Submission Author:
Marcos Paulo Simões Barbosa , MA
Co-Authors:
Marcos Paulo Simões Barbosa, CARMEM NASCIMENTO, Ronaldo Silva Paixão, Waldemir Passos Martins, Valter Alves de Meneses
Presenter: Marcos Paulo Simões Barbosa
doi://10.26678/ABCM.COBEM2023.COB2023-0225
Abstract
The corrosion of materials is, currently, one of the major cause of failures and shutdown of equipment and machines in general. In the case of air conditioning systems, the process of corrosion in the copper coils cause numerous losses as efficiency reduction and life time reduction, as well as, major electric power consumption. Furthermore, there are the environmental impacts caused by the leak of the cooling gases, classified as greenhouse gases. Although the copper is a material that presents a remarkable corrosion resistance, characterized by the formation of a passivation layer which protects the material from the attack of corrosive compounds of the atmosphere, in high salted concentrated environments, as coastline, the corrosion process is accelerated by chlorides and by the imperfections in the passivate layer. In this regard, the objective of this paper is evaluate the inhibitor potential of an organic varnish coating added by diverse concentrations of a natural extract of Aloe vera applied in the surface of copper used for air conditioning applications. Aloe vera was chosen for this application because it is a green, non-toxic inhibitor, less aggressive to the environment. Also, this green extract has a good precedent as a corrosion inhibitor when used in other metallic material. For this purpose, the copper tubes were painted with the mixture of organic varnish and the Aloe vera extract in different concentrations, followed by electrochemical impedance spectroscopy and potenciodynamic polarization tests, performed in an environment with 3,5% sodium chloride (NaCl), to assess the inhibitor potential and the corrosion rate, respectively. The results showed that the layer of varnish and Aloe vera presents itself as a very efficient corrosion inhibitor in copper coils in saline environments, reducing the corrosion rate of the material by the formation of a physical barrier between the metal and the corrosion media. Also, the efficiency of the protective layer increases as the concentration of Aloe vera added to the varnish increased.
Keywords
corrosion, Copper, air conditioning, Aloe vera, natural extract
