Perfil dos siloxanos em biogás e biometano gerados em aterro sanitário

Abstract

Biomethane has become an important renewable energy option. It can be obtained through the purification of biogas, originated as a product of the anaerobic digestion of organic matter from agricultural, industrial and urban waste. The main objective of the biogas purification process is to increase its calorific value, to produce more energy and reduce the emission of carbon dioxide into the atmosphere. However, even after the purification process, the biomethane may have traces of siloxanes in the composition, deriving from biomass. Thus, these compounds can come from cosmetics, detergents, defoamers, antistatics, solvents, paints, car waxes, etc. Siloxanes can polymerize, depositing themselves in the form of a silicone paste on the walls of motors and compressor impellers, causing problems and generating a certain periodicity in equipment maintenance. Siloxanes are a subgroup of silicon containing bonds with oxygen and functional organic radicals. The objective of this paper is analyze the composition of the siloxanes present in biomethane in the landfill in the metropolitan region and to observe the purification of biogas into biomethane for a variety of siloxanes. The method used was gas chromatography coupled to a mass spectrometer (GC-MS) and the purification method was Selexol™. A very satisfactory result was obtained, reaching more than 99.52% of purification, being within the current specific norms for siloxanes and biofuels.