Avaliação do ciclo de vida de tecnologias alternativas no sistema BRT do transporte Público de Curitiba

Abstract

The quality of every Lifecycle Assessment (LCA) depends intrinsically upon the quality of the inventory that is used. The inventory raising is a time-consuming task because it consists on describing in details the phases of production, utilization and discard of the product throughout its life cycle. This study intends to evaluate a part of the public transport system of Curitiba, the bi-articulated buses, model B340M, and compare them to alternative technologies operating in five of the city´s BRT exclusive corridors. The objects of the study were vehicles homologated according to Proconve´s P5 and P7 phases, as well as utilizing fuel mixes B7 and B100, in the configurations articulated, bi-articulated and hybrid articulated. The data related to the materials used for the production of B340M were extracted from the manufacturer´s product management tool (Kola) that provided a list of components with over than 3000 part numbers and 94% of the chassis composition was identified. For the body, estimated values had to be used due to lack of response from the bodybuilders. The company´s sustainability report provided the data needed to model the production inputs and outputs of the plant in Curitiba. The datasets of the articulated and hybrid configurations have been scaled according to scale-factors in order to be compared. For the use phase, it was necessary to rise the BRT operating cycle and therefore, a series of data acquisition sets was performed, using atmospheric pressure sensors and GPS. Such data were then treated in order to describe the routes´ topography and operating dynamic. Those cycles were used as input data for the fuel consumption simulation. By using emissions factors, it was possible to quantify the emission of regulated pollutants during the use phase. For the discard phase, ecoinvent data were used, and 100% of the metals were considered to be recycled, as well as the batteries of the hybrid vehicle. The Impact Assessment Methods used were IMPACT 2002+, CML 2000 and Eco-indicator 99 whereof the last two were used for sensibility analysis. The utilization phase still plays a major role on the environmental impact related to bus usage in comparison with the other phases, mainly due to the fuel consumption, either fossil or biogenic Diesel. However, the enhancements of the automotive industry related to pollutants control allow the reduction of such impacts by developing and adopting new technologies. Based on the objectives and scope of this assessment, it was possible to conclude that the biggest impact is in Human Health and that solution technologically more evolved, complying with stricter emission legislations like Proconve P7 have an significant advantage compared to the current bus fleet operating at Curitiba.