An integrated sustainable system fueled by Co-Combustion of legume straw biomass and synthesis gas of SOFC: Optimization study using Signal-To-Noise ratio analysis

Abstract

A novel tri-generation system of power, heating, and freshwater is developed in this study. The system integrates of a supercritical CO2 Brayton cycle, a solid oxide fuel cell, and a desalination system of humidification-dehumidification type. The system is fueled by a combustion of the synthesis gases of the solid oxide fuel cell helping by a legume straw biomass flow. The heat is recovered from the combusted gases and triggers the supercritical CO2 Brayton cycle and the desalination system. The key variables of the solid oxide fuel cell are evaluated and their influences on the voltages are examined in details. They are optimized using Taguchi approach and signal-to-noise ratio analysis to achieve the maximum solid oxide fuel cell power. Current density of 9375 A/m2, utilization factor of 0.7, temperature of 900 K, steam to carbon ratio of 2, anode recycling coefficient and cathode recycling coefficient of 0 are recognized to be the optimal conditions. The fuel cell power is 625.3 kW in this optimal state. The system provides 674.6 kW of net power, 157.3 g/h of mass flow rate of freshwater and 13812 kg/h of mass flow rate of hot water in its optimum condition.