Combustion of pellets produced from corn straw and cashew nut shell in residential and industrial scenarios: Chemical, thermal and emission analyses.

The Brazilian Northeast region has considerable agricultural potential for corn and cashew nuts production. Residues from these cultures can be densified into pellets and used as heat generators in industries and homes. In this study, corn straw pellets (CSP) and cashew nut shells pellets (CNSP) were handmade, together with a variation using glycerol as a binder (CSGP and CNSGP). All pellets were subjected to chemical, thermal and exhaust gas analyses of their combustion. All analyses were based on two different scenarios: (i) the use of CSP and CSGP for energy supply in residential use and (ii) the use of CNSP and CNSGP for energy supply in industrial use. All pellets were subjected to chemical, thermal and exhaust gas analyses of their combustion. Chemical analysis involved the study of various fuel properties, comprehending moisture content (%U), bulk density (kg m-3), volatile materials (%V), ash content (%C) and fixed carbon (%FC), and all evaluated pellets met two or more international trading standards. The combustion process analyses in the residential scenario showed higher average temperatures and lower carbon monoxide (CO) and nitrogen oxide (NOx) concentrations obtained during CSP combustion than those of CSGP, and in the industrial scenario showed average similar temperatures and lower CO and NOx concentrations obtained during CNSP combustion than those of CNSGP. Ours results demonstrate the great potential of corn straw and cashew nut shells as crops to be integrated into the biomass supply chain for energy generation and agro-ecological development.

Lung injury caused by exposure to the gaseous fraction of exhaust from biomass combustion (cashew nut shells): a mice model.

Currently, to reduce the use of nonrenewable energy sources in energy matrices, some industries have already incorporated biomass as a source of energy for their processes. Additionally, filters are used in an attempt to retain the particulate matter present in exhaust gases. In this work, the emission gases of a cashew nut shell (CNS) combustion reactor and the deleterious effects on the respiratory system of mice exposed to gaseous fraction present in CNS emissions (GF-CNS) are analyzed. The system for CNS combustion is composed of a cylindrical stainless steel burner, and exhaust gases generated by CNS combustion were directed through a chimney to a system containing two glass fiber filters to retain all the PM present in the CNS exhaust and, posteriorly, were directed to a mice exposure chamber. The results show changes in the variables of respiratory system mechanics (G, H, CST, IC, and PV loop area) in oxidative stress (SOD, CAT, and NO2-), as well as in the histopathological analysis and lung morphometry (alveolar collapse, PMN cells, mean alveolar diameter, and BCI). Through our results, it has been demonstrated that even with the use of filters by industries for particulate material retention, special attention should still be given to the gaseous fraction that is released into the environment.

Changes of respiratory system in mice exposed to PM4.0 or TSP from exhaust gases of combustion of cashew nut shell.

Air pollution is a topic discussed all over the world and the search for alternatives to reduce it is of great interest to many researchers. The use of alternative energy sources and biofuels seems to be the environmentally safer solution. In this work, the deleterious effects on the respiratory system of mice exposed to PM4.0 or TSP, present in exhaust gases from the combustion of CNS were investigated, through data from respiratory system mechanics, oxidative stress, histopathology and morphometry of the parenchyma pulmonary. The results show changes in all variables of respiratory system mechanics, in oxidative stress, the histopathological analysis and lung morphometry. The results provide experimental support for epidemiological observations of association between effects on the respiratory system and exposure to PM4.0 or TSP from CNS combustion exhaust gases, even at acute exposure. It can serve as a basis for regulation or adjustment of environmental laws that control the emissions of these gases.