Utilização de peneira molecular para purificação do gás de aterros sanitários

Abstract

Urban Solid Wastes – USW – generated daily by the operating dynamics of society, represent a serious environmental problem, bringing consequences. The organic matter present in the MSW undergoes anaerobic decomposition in landfills, producing a gas mixture: landfill biogas. About 45% to 55% of landfill biogas consists of methane (CH4), constituting as an excellent energy front matrix other in force and renewable. However, CO2 as a product of anaerobic digestion, needs to be removed. About 35% of landfill biogas is composed of carbon dioxide, in addition to this that pollute the atmospheric environment, does not release energy in the combustion process. The CO2 removal can be accomplished by adsorption technique. Adsorption is a separation mechanism that involves a fluid phase – the components to be separated and a solid phase – solid adsorbent. To perform the removal of CO2, it was employed as a solid adsorbent, molecular sieve type 4A zeolite. Zeolites have micro cavities called pores where adsorption no occurs. An important property of zeolitas is the surface area as it provides space for the adsorption to potentially take place. The obtained zeolite was characterized by means of techniques such as scanning electron microscopy techniques - SEM - and X-rays diffraction - XRD. It proceeded with mixed adsorption experiments of CO2 / CH4, applying the Langmuir isotherm, which this adapted well to experienced data. The zeolites produced were formed into pellets and thus introduced in quartz cartridges. In Landfill West Metropolitan Caucaia - ASMOC – was chosen three biogas emission drains. The CO2 removal increased with increasing mass of zeolites. There was also there moval of other components present in the biogas. The adsorption capacity per cartridge did not undergo abrupt changes. Zeolites have proven very selective for CO2 front of CH4. Cartridges with smaller masses suffered saturation in less time, justify in the effectiveness of separation. However, being a material considered new in landfill biogas purification, it deserves to be explored scientifically.