چکیده مقاله
Purpose: Gas hydrates in sour natural gas containing H2S pose critical flow assurance risks Conventional thermodynamic inhibitors work but raise environmental and regeneration concerns Urea, a biodegradable candidate, has been little studied for sour systems This work experimentally determines three phase equilibrium V–Lw–H for a representative sour mixture CH4 C3H8 H2S with 0–50 wt% urea, and compares the results with i literature data for a sweet CH4 C3H8 system and ii 20 wt% monoethylene glycol MEG for the same sour gas Methods: Experiments used a stirred high pressure autoclave under isochoric T cycle conditions Temperature and pressure accuracies were ±0 10 K and ±0 13 MPa Urea solutions 0–50 wt% in deionized water were tested, and equilibrium identified by slow heating dissociation The same setup and gas composition benchmarked against previously measured MEG 20 wt% data Results: Urea acted as an effective THI, shifting the hydrate equilibrium to lower temperatures across 2 29–12 08 MPa The equilibrium temperature depression ΔTₕ increased with concentration, reaching ≈13 K at 50 wt% At 20 wt%, urea produced ΔTₕ ≈ 4 51 K at matched pressures , whereas MEG 20 wt% yielded an average ΔTₕ ≈ 5 60 K, i e , ~1 1 K stronger suppression The ΔTₕ–concentration trend was nearly linear up to 30–40 wt%, followed by mild leveling, and agreed in magnitude and slope with published sweet gas CH4 C3H8 results, indicating that H2S does not materially diminish urea efficacy within the studied range Conclusion: This fully experimental study demonstrates that urea is a viable green thermodynamic inhibitor for sour natural gas hydrates, providing moderate, concentration dependent suppression ≤10–13 K with reproducible results While MEG 20 wt% is ~1 K stronger, urea offers comparable inhibition and better environmental attributes, supporting its practical use where moderate temperature shifts meet design requirements
کلیدواژهها
نویسندگان
Mohammad Amin Behnam motlagh
Department of Petroleum Engineering, Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, Iran
شیوه ارجاع
Behnam Motlagh, Mohammad Amin,1404,A green approach to hydrate control in sour natural gas: Evaluating Urea as a thermodynamic inhibitor,The 3rd National Conference on Environmental Challenges: The role of industry, mining, and society in developing green governance,Tehran
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