Integrating Coal Gasification into Gas Engine Power Plant: A Techno Economic Study at PLTMG Bangkanai

Abstract

Indonesia aims to achieve a 29% emission reduction by 2030 by reducing its reliance on coal-fired power plants. Gas-fired power plants offer a cleaner option with lower CO₂ emissions compared to coal-fired power plants (PLTU). The Bangkanai Gas Engine Power Plant (PLTMG) with a capacity of 310 MW currently operates with a capacity factor (CF) of only 28.47% due to limited gas supply. The gas demand at PLTMG Bangkanai is 66.04 BBTUD, while the available gas supply is only 20.33 BBTUD. On the other hand, Indonesia has substantial coal reserves, especially on Kalimantan Island, totaling 14 billion tons. This study investigates the technology of converting coal into Synthetic Natural Gas (SNG) to address the gas supply shortage at PLTMG Bangkanai. The coal-to-SNG process includes coal gasification, water gas shift (WGS) reaction, and methanation reaction. The modeling was performed using Aspen Plus software. The gasifier design used is an entrained-flow gasifier with a coal feed rate of 120 t/h, a gasifier temperature of 700 °C, and a pressure of 1 bar. The simulation results show that the SNG product has a high heating value (HHV) of 45.58 MJ/kg and a total gas production of 46.04 BBTUD, which is sufficient to meet the gas shortage at PLTMG Bangkanai of 45.72 BBTUD. The economic analysis for coal-to-SNG processing, including the gas pipeline to the power plant, reveals a CAPEX of US$ 102,120,735 and OPEX value is US$ 107,542,643 per year. The IRR value obtained was 16.18% and the payback period was 5.14 years assuming the SNG selling value was 7.5 USD/MMBTU.