R Chandrasekaran1 and N Gopalakrishanan2
1Esvin House, No.13 Old Mahabalipuram Road, Seevaram Village, Perungudi, Chennai, Tamil Nadu 600096, India
2South Indian Sugarcane and Sugar Technologists’ Association of India, 49, 3rd Main Road, Adyar, Chennai, Tamil Nadu – 600020, India;
This study was undertaken to address the high specific thermal energy consumption in sugar manufacturing, which directly impacts production costs and environmental sustainability. Ponni Sugars Erode Limited sought to overcome these challenges by investing in a modern, high-efficiency high-pressure cogeneration system. The project involved transitioning from conventional low and medium pressure boilers to an advanced high-pressure boiler operating at 112 kg/cm², coupled with a double extraction condensing steam turbine. The system was designed to utilize multiple biomass fuels in addition to bagasse and pith, optimizing thermal efficiency and steam evaporation. A key innovation was the adoption of an air-cooled condenser (ACC) to minimize water usage, replacing the more commonly used water-cooled systems. Additional energy saving features included the use of variable-frequency drives (VFDs) on boiler fans and an energy-efficient boiler feed water pump to reduce internal power consumption. The implementation of the high-pressure cogeneration plant resulted in a significant reduction in specific steam consumption and an increase in overall cycle efficiency. The plant now supplies steam and power for internal processing while also generating surplus electricity for export to the grid, thereby enhancing revenue. The integration of ACC technology contributed to improved condenser vacuum and sustained exhaust steam quality, leading to enhanced net power output, and energy saving components effectively reduced auxiliary power usage within the station. Ponni Sugars Erode’s high-pressure cogeneration system demonstrates how technological upgrades in boiler pressure, fuel flexibility and energy efficient equipment can collectively optimize plant performance. This model not only lowers production costs and improves energy self-sufficiency but also supports environmental conservation through reduced water consumption and renewable energy export. The case serves as a replicable blueprint for other sugar mills aiming to modernize their energy systems and improve profitability.