RESUMO
The cement industry is intensive in energy and feedstock use. It includes three main phases: raw materials and energy supply, transport, and manufacturing. The sector is known for its considerable environmental impacts. The increase in energy efficiency and the use of non-fossil fuels and raw materials are considered mature technologies in cement industries. We evaluate different environmental impacts of the production of 1 t of cement in four Brazilian scenarios. We compare one business-as-usual reference scenario (case 1) to three alternative 2030 carbon mitigation sectoral plan scenarios (cases 2, 3a, and 3b) that assume mature technologies. We analyze all 18 impact categories within the ReCiPe 2016 Life Cycle Assessment methodology. Results show reductions in 17 impact categories, ranging from no change in ozone depletion (case 2) to 39% reduction in fossil resource scarcity (case 3b). The effects on climate change decreased 14% in case 2 and 33% in cases 3a and 3b. The clinkerization process is the greatest contributor to atmospheric impacts, while raw material consumption to toxicity impacts. In contrast, there is no single main process contributing to resource depletion impacts. The changes in cement production lead to carbon emission reductions above expected levels and to reductions in other environmental impact categories modeled in ReCiPe 2016 method.
Assuntos
Indústria da Construção , Monitoramento Ambiental , Perda de Ozônio , Animais , Brasil , Mudança Climática , Meio AmbienteRESUMO
RESUMO O presente estudo analisou o potencial de recuperação energética dos resíduos sólidos urbanos (RSU) e o balanço de emissões de gases de efeito estufa (GEE) resultante no município do Rio de Janeiro, Rio de Janeiro, com base em três cenários tecnológicos alternativos. Os potenciais de geração foram calculados para a recuperação de gás de lixo (GDL) em 363,98 GWhe.ano-1 e 0,181 MWhe.t-1, para a biodigestão anaeróbica em 367,27 GWhe.ano-1 e 0,247 MWhe.t-1; e para a incineração em 1.139,33 GWhe.ano-1 e 0,459 MWhe.t-1. Os indicadores de intensidade de carbono mostram que, ao se considerar somente as emissões de GEE de combustão, a recuperação de GDL e a biodigestão anaeróbica apresentam os menores valores (7,488.10-4 tCO2eq.MWhe-1), enquanto a incineração apresenta o valor de 1,248 tCO2eq.MWhe-1. Por outro lado, ao se considerar também as emissões de aterro associadas, os indicadores dos dois primeiros cenários correspondem a 8,191 e 3,552 tCO2eq.MWhe-1, respectivamente.
ABSTRACT The present study analyzes the energy recovery potential of municipal solid waste (MSW) and the resulting greenhouse gas (GHG) emission balance in the city of Rio de Janeiro, Rio de Janeiro, Brazil, based on three alternative technological scenarios. The generation potentials were calculated for waste gas recovery (WGR) to be 363.98 GWhe.year-1 and 0.181 MWhe.t-1, 367.27 GWhe.year-1 and 0.247 MWhe.t-1 for anaerobic biodigestion, and 1.139.33 GWhe.year-1 and 0.459 MWhe.t-1 for incineration. Carbon intensity indicators show that, when only considering GHG emissions from the combustion process, WGR recovery and anaerobic biodigestion present the lowest values, of 7.488.10-4 tCO2eq.MWhe-1, while the value for incineration corresponds to 1.248 tCO2eq.MWhe-1. On the other hand, when considering associated landfill GHG emissions, the indicators in the first two scenarios correspond to 8.191 and 3.552 tCO2eq.MWhe-1, respectively.