Configuration optimization of a multi-generation plant based on biomass gasification

Heat integration and configuration optimization of a unique cycle based on biomass gasification are presented. The system provides heat, freshwater, and electricity to an area located in the southern part of Iran using the gasification of sugarcane bagasse. The main question to be responded is to find the optimum configuration which minimizes the total external utility consumption. It is assumed that 34500 kg/day of bagasse is available and the electricity, heating, and water demand of the area should be covered. It is concluded that the total utility consumption is 3113.69 kW if no heat integration is utilized. On the other hand, partial heat integration results in a total utility consumption of 590.93 kW. The least possible utility consumption which occurs in full heat integration condition is 214.6 kW. By increasing the gasification temperature from 900 °C to 915 °C, it is possible to enhance the integration by removing one of the heaters. The sensitivity analysis shows that the highest CHP efficiency occurs for a biomass flow rate of 32970 kg/day. It is concluded that energy integration techniques serve well in the identification of the optimum gasification temperature and biomass flow rate which lead to the minimum utility consumption and highest CHP efficiency. •Pinch analysis is used to find the optimum configuration with minimal utility consumption.•Utility consumption in partial integration is almost three times the utility consumption in full integration.•Biomass flow rate which lead to the highest CHP efficiency is determined.•Increasing the gasification temperature enhances the heat integration.•Power, heat, and water demand of an off-grid area can be met using the proposed system.