(211g) Analysis of the Environmental Impact of the Pig Iron Production Process By the 12 Principles of Green Chemistry

Sustainable development is a topic that has been widely approached internationally in the academic and industrial spheres. However, this issue is not limited to the emission of pollutant gases into the atmosphere and its consequent acceleration of the phenomenon on the greenhouse effect, but to a sequence of human actions that greatly impact the social, environmental and economic aspects of a society. Green Chemistry (GC), therefore, was conceived to minimize or avoid these adverse risks to the pillars of sustainability. It is also considered as a philosophy, expressed in the twelve principles, GC aims to develop products through cleaner and safer chemical transformations - socially and environmentally - leading to economic changes more cost-effective to the processes involved. It is known that Brazil is responsible for the third largest iron production in the world (the main raw material of steel) and that the metallurgical sector has a great influence on the sustainability factors. In this way, the present work aims to use metrics related to the 12 Green Chemistry Principles to evaluate the impact of pig iron production and to compare two processes with different reagents in order to identify the most sustainable route as well as to provide the guidelines for “greener" product design. The raw materials used in the comparison were Chinese coke and petroleum coke, which is produced from the cracking of heavy residual oils in waste conversion units called Delayed Coking Units (DCU). In addition, with the purpose of evaluating each principle of Green Chemistry for the processes under study, this work proposes a computer program that allows them to be evaluated one by one and define, automatically, which route under analysis is “greener”. The results show that the petroleum coke used as a reagent has a lower impact on the environment than the Chinese one. However, in order to minimize these impacts from both processes, it is possible to use renewable sources as feedstock, such as biomass. Biomass has a low cost for energy production and because it is renewable, it allows the reuse of waste, besides being less polluting than other sources of energy such as oil and coal. Thus, the next step for this work is the evaluation of biomass as a sustainable alternative for the production of Brazilian pig iron. It is also worth noting that the studies focused on GC have little more than twenty years and that, in Brazil, they are in the beginning of development. Therefore, the proposal presented herein aims to promote both the fomentation of research in this area and its applicability in industrial processes - especially in the metallurgical sector - and also to provide guidelines for a more sustainable design to the country's iron production processes.