Preliminary thermal evaluation of disposable babies diaper viewing energy recycling

Abstract

Human population growth, high consumption and unsustainable management of products and services are exceeding the sustainable use of natural resources. The use of disposable diapers, not only baby but also geriatric ones, reaches a high value, increasing considerably the urban solid residue generation. Currently, all this urban solid residue goes to landfills, taking up to 400 years to decompose, as most of its components are derived from oil. Its use as energy source, as it is already done with the cane bagasse, would bring great benefits, such as power generation and waste reduction. The objectives of this work were to identify the composition of each layer of a disposable diaper for babies and estimate the potential energy through combustion, employing the thermal analytical techniques TG/DTG/DTA, aiming at the reduction in the waste disposed in landfills, contributing in this way to an effective solid waste residue management. The layer 1 presented an endothermic peak at 165 degrees C, suggesting the presence of polypropylene, and layer 2 presented an endothermic peak at 130 degrees C, possibly consistent presence of polyethylene according to the manufacturer's information and infrared analyses. Through the DTA curves of layers 4, 5 and sodium polyacrylate (PSA), it is observed that the fusion temperatures of the polymer are around 425 degrees C indicating the presence of PSA in both layers. The disposable diaper combustion releases approximately 12 kJg(-1), lower than the heat released from sugarcane that is around 17 kJg(-1); if used to obtain energy would help the removal of the diaper from the environment by reducing space occupied by that residue in landfills, contributing to environmental sustainability.