Methodology Development for Capturing Co2 and Precursor Gases of Greenhouse Effect From the Exhaust of Flex-fuel Internal Combustion Engines

Derived largely from the combustion of fuels used in automotive vehicles, CO ₂ and precursor gases of greenhouse effect are important emission gases and deserve attention. This paper proposes a method to remove these gases by adsorption, through the capture and separation in exhaustion of vehicles with flex-fuel technology. The technique is feasible because it is based on the solid adsorption capacity and selectivity for CO ₂ and precursor gases. The characterization of the used adsorbents, natural ZN2040 and synthetic Oxan_X, show unique characteristics, especially the surface area, adsorption at low pressures, stability to wet gases, application at high temperature, high Si/Al ratio in the crystal structure and the presence of elements such as Fe, Ca, K and S. The adsorbents were arranged in a horizontal fixed bed column, installed in the front vehicle noise muffler of the exhaust system. The Oxan_X synthetic zeolite with improved performance, showed reductions in average of 2,20% of CO ₂ about 17% on the precursor gases, mainly CO, both for Gasoline 22% EAAF (Ethyl Alcohol Anhydrous Fuel) and ethanol burning. In addition, it allowed the reduction of other vehicle pollutants. In the long term, the use of vehicular fixed bed column contributes to a reduction of approximately 764000 tons of CO ₂ and 23300 t of CO when the vehicle is operating with Gasoline, and 1168000 tons of CO ₂ and 18000 t of CO when it is operating with Ethanol. Considering the vehicles of motorization 1.4 L to 2.0 L, and employing 2.0 kg of adsorbent.