Effect of process parameters on bioelectricity production, energy and environmental performance

Abstract

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.