Parametric analysis of operating conditions on compressed natural gas production in Nigeria

Abstract This study addresses a critical gap in research on integrated compressed natural gas (CNG) production processes in Nigeria, despite the country’s abundant natural gas reserves and governmental push for CNG adoption. A detailed parametric analysis was conducted on a 25 MMcuft/d modular gas plant using the Aspen HYSYS sensitivity analysis tool to assess the effects of pressure, temperature, and flow rate across the dehydration, sweetening, and compression zones on critical performance indicators. Maintaining feed gas temperatures between 25 and 30 °C in the dehydration zone optimized water removal efficiency while minimizing energy consumption. The sweetening zone analysis identified optimal diethanolamine (DEA) temperatures of 40–60 °C, pressures of 1–2 bar and molar flow rates between 895,000 and 897,000 kgmol/h to balance CO2 removal efficiency with energy requirements, while absorber bottom stage pressure impacted gas quality and quantity, with an optimal range of 38–48 bar. Multi-stage compression, particularly three-stage configurations, provided significant energy savings of up to 15.2% over single-stage systems. These findings offer valuable guidance for optimizing CNG production processes and maximizing yield and quality while minimizing energy consumption. The results provide a foundation for enhancing Nigeria’s capacity to leverage its natural gas resources for cleaner fuel alternatives, supporting both current and future CNG production facilities.