Comparative Emissions of Syngas, Biogas, and LPG in Spark-Ignition Engines for Sustainable Power Generation
Received: 5 August 2025 | Revised: 28 August 2025 | Accepted: 9 September 2025 | Online: 30 September 2025
Corresponding author: Fatima Amer Khudhur
Abstract
This study provides a comparative analysis of the performance and emissions of internal combustion engines powered by different alternative fuels: syngas from agricultural and woody biomass, biogas, and Liquefied Petroleum Gas (LPG). Syngas was generated using a reduction gasifier and was utilized in a 10 kW Spark-Ignition Engine (SIE), whereas biogas and LPG were tested in a 1 kW SIE. The results from the smaller engine were mathematically adjusted to match the 10 kW SIE for a consistent comparison. The engine performance was assessed based on Brake Thermal Efficiency (BTE) and Specific Fuel Consumption (SFC). Additionally, exhaust emission levels of carbon monoxide (CO), carbon dioxide (CO₂), nitrogen oxides (NOₓ), and unburned hydrocarbons (HCs) were measured and compared. Syngas produced the highest CO₂ emissions, particularly from wood-derived biomass, with values reaching up to 3.7821 kg/kWh. In contrast, LPG and biogas emitted significantly lower CO₂ levels. Syngas also showed higher CO and HC emissions, reflecting incomplete combustion and fuel inefficiency, while LPG and biogas exhibited lower CO and minimal HC emissions. The NOₓ emissions were notably higher when syngas fuel was used due to elevated flame temperatures, while LPG and biogas demonstrated a better combustion efficiency with lower NOₓ levels. Overall, this study highlights the potential of biomass-derived gaseous fuels for low-emission and sustainable energy production. While LPG offers stable combustion, syngas and biogas present promising results, particularly as waste-derived fuels, contributing to decentralized and eco-friendly energy generation.
Keywords:
syngas, biogas, biomass gasification, internal combustion engine, engine performance, LPGDownloads
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