Filtro compósito para retenção de co2 a partir de resíduo agroenergético (endocarpo da acrocomia aculeata – Macaúba): obtenção e caracterização

Abstract

Technological development and economic growth are related to energy consumption, with fossil fuels being the main source. The combustion of these non-renewable products generates polluting gases such as carbon dioxide and monoxide, which worsen the greenhouse effect and exacerbate global warming. On the other hand, mitigation actions seek to reduce greenhouse gases to stabilize the climate system. This present work, based on an ecological practice, aims to produce a composite membrane using activated carbon (AC) associated with a polyurethane (PU A added to PU B) polymer matrix, to retain carbon dioxide (CO2). The AC was produced from the endocarp of the macaúba fruit and characterized by ash content, SEM, TGA, DSC, and EDX, which allowed the conclusion that the produced material is carbonaceous and porous with different dimensions and shapes. The composite membrane was then made, keeping the weight of the polymer matrix fixed using 5 grams of PU B and 3 grams of PU A, varying only the amount of AC. Three samples, with 5 repetitions each, were produced, obtaining sample 1 with 0.8 grams of CA, sample 2 with 2.4 grams of CA, and sample 3 with 4 grams of charcoal. The filter was then characterized by TGA, DSC, SEM, and infrared spectroscopy (IRS), confirming the production of an organic composite membrane in which CA was incorporated into the matrix, presenting thermal stability up to 270°C and well-defined characteristic wavelengths. To test the functionality of the filters, a membrane holder was made. The filter was inserted into this holder, attached to the exhaust of a diesel engine, remaining stationary with the engine running for ten minutes for each test membrane. After use, the membranes were placed in plastic bags and sealed. In order to investigate the CO2 adsorption, the membranes were characterized before and after use using the infrared technique (IRS). The spectral images of the IRS revealed different values for the transmittance of the membranes before and after exposure to burnt gases. Percentagewise differences of 2 to 10% were recorded, demonstrating the retention and absorption of some gaseous substances present in diesel combustion. The statistical analysis confirmed that the membranes are statistically equal in terms of transmittance and that the amount of reinforcement impregnated in the matrix did not influence the incidence of light in the samples.