Plant Performance with Addition of Pulverizer to Support Grid Reliability under Declined Coal Quality: A Case Study at Lontar CFSPP

Abstract

To address increasing electricity demand and the challenges of declining coal quality, Unit 1 of Lontar Coal Fired Steam Power Plant (CFSPP) implemented a five-pulverizer operation, deviating from the standard four-pulverizer configuration. This study evaluates the operational and performance impacts of this approach under low rank coal (LRC) conditions by analyzing key indicators such as load output, specific fuel consumption, auxiliary power consumption, unburned carbon, emissions, and Net Plant Heat Rate (NPHR). Results show that five-pulverizer operation improved load stability and increased gross and net generation by 3.9-6.3% achieving a daily peak of 6.7 GWh. However, it also raised auxiliary power usage by approximately 2.6 MW, worsened NPHR to 3373 kcal/kWh or 19% above the PLN Pusertif baseline, and increased Specific Fuel Consumption (SFC) by 4-18%. Combustion completeness declined, as indicated by higher unburned carbon by 69% in bottom ash and 14% in fly ash. Despite these drawbacks, SO₂ maximum is 501 mg/m³ and NO₂ maximum is 360 mg/m³ emissions remained well below regulatory limits 550 mg/m³. The findings suggests that full-pulverizer operation can serve as an effective short-term reliability strategy during low quality conditions but requires further optimization to balance efficiency, reliability, and environmental compliance.