Utilização do bagaço da mandioca como isolante térmico em edificações: avaliação comparativa do desempenho em módulos-testes sob condições reais de exposição

Abstract

Against issues related to environmental impact cutbacks, researchers are looking for ways of replacing nature extracted materials or to use industry waste, as of the cassava root bagasse from the starch manufactory. Nowadays there is no processing for this bagasse that is economically viable, due to the elevated investments required and a low selling price of the residue, hence, as final waste disposal, the majority of the industries donate it for animals feeding (directly or for feed manufacturing). Therefore, this study’s goal is to analyze the solid’s by-product from the cassava processing’s (cassava root bagasse) prospect as an alternative thermal insulation material aiming to be used in construction, contributing for reducing energy consumption and minimizing environmental impacts due to waste disposal since this residue is mostly disposed without any treatment into the environment, causing great impact due to the presence of cyanogenic glycoside linamarin in its composition, which is cyanide hydrolysable, that leads to water and air pollution as well as public health problems. Due to the relevance of further study on cassava root bagasse’s applications, thermal insulation plates were made as an alternative use of this residue and the results are presented on this research. To this end previous experimental procedures were made using different materials combined with cassava bagasse (vegetable polyurethane based resin, PVA glue and tung oil) aiming to obtain a mixture for making the insulating plates, which was noted that the mix containing 1 kg of cassava bagasse, 0,18 dm³ of component A, and 0,35 dm³ of component B from the vegetable polyurethane based resin, and 0,70 kg of PVA glue was the best performant. Afterwards standardized test modules with three different insulating materials were made (a reference model, glass wool mix and cassava bagasse mix) and placed on an open area between 05/05/2021 and 14/01/2022, exposed to weather variations. The temperature and air humidity were monitored for 13 hours daily using a weather station to collect data, thus allowing the results to be compared for each of the different insulation material used. The cassava bagasse samples presented similar performance as thermal insulation material to that of the glass wool with the results showing its thermal energy retaining capability both on hot and cold days.