ENG. ANDREW OMWENGA
Chemical & Process Simulation Engineer • Thermodynamic Specialist
Routine Flare Gas Recovery & Techno-Economic Monetization (Gas-to-Power & NGL Extraction)
Section 1.0 — Simulation & Facility Metadata
Section 2.0 — Executive Summary
Aspen HYSYS process simulation and screening techno-economic analysis investigating the transformation of routine associated gas flaring into commercial energy assets: 3-stage separation, multi-stage compression, NGL recovery, MDEA amine sweetening, and Gas-to-Power vs Pipeline Sales.
Section 3.0 — Problem Statement & Operating Bottlenecks
Routine associated-gas flaring is simultaneously an environmental catastrophe and a massive destruction of commercial value. Flaring releases vast quantities of CO₂, methane, and toxic sulfur oxides, while wasting energy that could electrify industries. Upstream operators often treat flare gas as an unavoidable waste product due to fluctuating flow rates, low wellhead pressures, high sour acid gas content (H₂S and CO₂), and remote field locations. Turning routine flaring into an economic asset requires rigorous chemical engineering flowsheet design to compress, dehydrate, sweeten, and fractionate the gas, coupled with techno-economic decision analysis to identify whether Gas-to-Power (GTP), pipeline injection, or liquefied petroleum gas (LPG) extraction yields the highest risk-adjusted net present value.
Section 4.0 — Objectives & Rigorous Simulation Methodology
Rigorous Aspen HYSYS flowsheet simulation using Peng-Robinson EOS for upstream separation and compression, and Acid Gas - Chemical Solvents thermodynamic package for MDEA gas sweetening. Process includes 3-stage compression with interstage cooling, mechanical refrigeration chiller (-20 °C) for NGL dewpoint control, and an amine absorption-regeneration loop (20-tray absorber, 18-tray regenerator at 2.0 bar). Economic screening model built in Python evaluating 15-year lifecycle cashflows at a 10% discount rate.
Section 5.0 — Simulation Results & Thermodynamic Findings
The techno-economic analysis demonstrates that there is no universal 'silver bullet' for flare gas recovery; the optimal route depends on infrastructure proximity and power grid access. While Direct Gas Sale features lower capital expenditure and a rapid 1.8-year payback, the Gas-to-Power pathway generates nearly double the overall Net Present Value ($211M vs $114M) by transforming low-value gas into high-value electricity for power-hungry regional grids or oilfield electrification. Crucially, removing heavy NGLs prior to sweetening prevents amine foaming in the MDEA column and provides a high-margin liquid revenue stream.
Section 6.0 — Core Engineering Takeaways
Section 7.0 — Model Assumptions & Future Recommendations
Economic metrics represent screening-level estimates (AACE Class 4, ±30% accuracy) based on stated financial assumptions and do not constitute an EPC vendor quotation or bankable feasibility study.
Modular mobile mini-LNG liquefaction screening for highly stranded remote wellheads, and dynamic simulation of flare header surge pressure relief.
Section 8.0 — Consultant Conclusion & Verification Sign-off
Process simulation in Aspen HYSYS elevates flare gas recovery from a compliance burden into a premier capital investment opportunity. By capturing 15.78 t/h of waste gas, operators simultaneously eliminate catastrophic flaring emissions, generate 69 MW of reliable electricity, and capture up to $211M in net present value.
