Verifying the Environmental and Energy Feasibility of Potential Improvement Actions in the Steel Production Chain in Brazil

The steel industry is an important pillar of the Brazilian economy. However, as in other countries, the process consumes significant amounts of resources and generates sludge, slag and air emissions. In order to improve the environmental and energy feasibilities of Brazilian steel sector a Life Cycle Assessment was carried out to identify impact sources associated with it. The analysis pointed the coal consumption as the main source of primary energy demand, and high carbon dioxide emissions in steel production, oil refining and electricity generation as the origin of climate change impacts. Three improvement alternative were proposed to reduce impacts: S1: the use of steelmaking gas to produce electricity; S2: installation of dry coke quenching technology; and, S3: replacement of the manganese ore supply. A second round of assessments indicated that changes due to S1 and S2 brought only slight gains concerning impacts, but S3 resulted in improvement in metal depletion

Life-cycle inventory for hydroelectric generation: a Brazilian case study

Representative Life-Cycle Inventories (LCIs) are essential for Life-Cycle Assessments (LCAs) quality and readiness. Because energy is such an important element of LCAs, appropriate LCIs on energy are crucial, and due to the prevalence of hydropower on Brazilian electricity mix, the frequently used LCIs are not representative of the Brazilian conditions. The present study developed a LCI of the Itaipu Hydropower Plant, the major hydropower plant in the world, responsible for producing 23.8% of Brazil's electricity consumption. Focused on the capital investments to construct and operate the dam, the LCI was designed to serve as a database for the LCAs of Brazilian hydroelectricity production. The life-cycle boundaries encompass the construction and operation of the dam, as well as the life-cycles of the most important material and energy consumptions (cement, steel, copper, diesel oil, lubricant oil), as well as construction site operation, emissions from reservoir flooding, material and workers transportation, and earthworks. As a result, besides the presented inventory, it was possible to determine the following processes, and respective environmental burdens as the most important life-cycle hotspots: reservoir filling (CO(2) and CH(4) emission: land use); steel life-cycle (water and energy consumption; CO, particulates, SO(x) and NO(x) emissions); cement life-cycle (water and energy consumption; CO(2) and particulate emissions); and operation of civil construction machines (diesel consumption; NO(x) emissions). Compared with another hydropower studies, the LCI showed magnitude adequacy, with better results than small hydropower, which reveals a scale economy for material and energy exchanges in the case of ltaipu Power Plant. (C) 2009 Elsevier Ltd. All rights reserved