Performance enhancement of a sugarcane bagasse-fired steam power plant through flue gas-assisted drying: a case study of Metehara Sugar Factory, Ethiopia

This study investigates the performance enhancement of a sugarcane bagasse-fired steam power plant at the Metehara Sugar Factory in Ethiopia by integrating flue-gas-assisted biomass drying. The primary objective is to evaluate how reducing the high as-received moisture content (~ 46%) of bagasse improves fuel quality and overall plant performance. A thermodynamic model of the existing simple Rankine cycle was developed using Engineering Equation Solver (EES) with IAPWS-IF97 water-steam properties. The model was applied to assess plant performance under two operating conditions: a base case using as-received bagasse and an upgraded case incorporating flue gas-assisted drying. Key operating parameters, including turbine inlet pressure (2 MPa) and condenser pressure (95 kPa), were maintained constant, while turbine inlet temperature varied based on combustion conditions. In the base case, the plant generates 9.03 MW of net power with a thermal efficiency of 22.56%. With the integration of flue gas-assisted drying, the reduction in moisture content increases the lower heating value and combustion temperature, leading to improved steam conditions. As a result, net power output increases to 16.61 MW, and thermal efficiency improves to 27.35%, representing an efficiency gain of 4.8 percentage points without additional fuel input. The results demonstrate that utilizing waste heat from boiler exhaust gases for biomass drying significantly enhances energy recovery and power generation capacity. This approach provides a practical and low-cost solution for improving the performance of biomass-fired power plants and supports more efficient utilization of available energy resources in the sugar industry.