This study examined the effect of Carbon Capture and Storage units on the environmental, energy and economic performance of the Brazilian electric grid. Four scenarios were established considering the coupling of Calcium Looping (CaL) processes to capture CO₂ emitted from thermoelectric using coal and natural gas: S1: the current condition of the Brazilian grid; S2 and S3: Brazilian grid with CaL applied individually to coal (TEC) and gas (TGN) operated thermoelectric; and S4: CaL is simultaneously coupled to both sources. Global warming potential (GWP) expressed the environmental dimension, Primary Energy Demand (PED) was the energy indicator and Levelised Cost of Energy described the economic range. Attributional Life Cycle Assessment for generation of 1.0 MWh was applied in the analysis. None of the scenarios accumulated the best indexes in all dimensions. Regarding GWP, S4 totals the positive effects of using CaL to reduce CO₂ from TEC and TGN, but the CH₄ emissions increased due to its energy requirements. As for PED, S1 and S2 are similar and presented higher performances than S3 and S4. The price of natural gas compromises the use of CaL in TGN. A combined verification of the three analysis dimensions, proved that S2 was the best option of the series due to the homogeneity of its indices. The installation of CaL in TECs and TGNs was effective to capture and store CO₂ emissions, but the costs of this system should be reduced and its energy efficiency still needs to be improved.

The expansion of the Brazilian energy supply from fossil sources prompted environmental concerns about the emission of Green House Gases (GHG). Furthermore, the Brazilian government was committed to the United Nations Framework Convention on Climate Change (UNFCCC) to reduce GHG emissions by 43% by 2030, compared to 2005. The aim of this study was to design the Brazilian electricity mix for 2030, while taking into account economic, technical and environmental criteria. In order to get this, Linear Programming optimization has been applied to obtain an electricity matrix with minimum cost of the Brazilian electricity generation system, considering GHG emission constraints – defined via the Life Cycle Assessment (LCA) technique –, as well as capacity generation and supply needs. In addition, LCA was also applied to obtain the environmental performance of the projected scenario and results were compared with those of 2005 and 2015. The analysis depicted that renewable sources represent 88% of the projected Brazilian electricity production in 2030, mainly hydropower, which accounts for 66%. In terms of Climate Change there is an impact reduction of 12% compared to 2005, while other categories such as Ionized Radiation and Terrestrial Ecotoxicity doubled and upped more than forty times. These findings led to conclude that environmental management should not be limited to GHG analysis, and must encompass other adverse effects. Moreover, this reinforces the importance of conducting analyses such as those provided by the LCA approach and include these results in the planning and decision-making processes of the energy sector.

This study evaluates the energy and environmental performance of a cogeneration system operating simultaneously with bagasse and straw in a rankine cycle. Different process conditions, defined in terms of boiler operating pressure, moisture content and straw addition rate, were analyzed. The combination of these parameters led to the elaboration of one hundred and twenty-five analysis scenarios. The energy profile was based on the energy performance indicator, which is the ratio between the exported electricity and the intrinsic energy of biomass consumed for its generation, and the environmental assessment was performed in terms of climate change. Scenario modeling was developed according to the conceptual framework proposed by the life cycle assessment technique with a 'from cradle-to-gate' coverage. Results indicate that the best energy and environmental performances (energy performance indicator = 0.193 and 688 kg CO2eq/MWh) were obtained with the highest pressure (100 bar) and addition rate (50%), and the lowest moisture content (10%). Moreover, straw moisture has more influence on the system environmental performance than its addition rate.