Techno-Economic and Sensitivity Analysis of Natural Gas Liquefaction Using the Propane Pre-Cooled Mixed Refrigerant (C3MR) Cycle

Document Type : Original Article

Authors
Sahar Arshtabar 1
Mojtaba Biglari 2
Mohammad Sadegh Valipour 3
1 Ph.D. Student, Faculty of Mechanical Engineering, Semnan University, Semnan, Iran
2 Associate Professor, Faculty of Mechanical Engineering, Semnan University, Semnan, Iran
3 Professor, Faculty of Mechanical Engineering, Semnan University, Semnan, Iran
20.1001.1/jgt.2026.2069422.1059
Abstract
Liquefied natural gas (LNG) is essential in the global energy transition because it allows for long-distance transportation of natural gas with reduced emissions. Improving the energy efficiency and economic feasibility of LNG liquefaction processes is therefore important. This study offers a comprehensive techno-economic analysis and sensitivity evaluation of natural gas liquefaction using the Propane Pre-Cooled Mixed Refrigerant (C3MR) cycle. A steady-state simulation was developed in Aspen HYSYS V12, utilizing the Peng–Robinson equation of state to accurately model the cryogenic behavior of multicomponent streams. The process was segmented into two integrated subsystems: propane precooling and mixed refrigerant subcooling, with performance measured through key indicators such as energy use, power requirements, and indirect CO2 emissions.
The results show that although the MR cycle uses slightly more electrical power than the propane precooling stage, it leads to lower overall energy use, less cooling water requirement, and significantly fewer environmental emissions. From an economic standpoint, cost estimates based on updated CEPCI indices indicate that these technical improvements result in strong financial performance, marked by high profitability and a quick payback period under typical LNG market conditions. Sensitivity analysis also indicates that higher natural gas feed rates, moderate refrigerant flow rates, and an inlet pressure near 65 bar best balance energy efficiency with economic return. Overall, the findings confirm that the C3MR cycle is a solid and practical option for large-scale LNG production, effectively connecting better thermodynamic performance with positive economic results.
Keywords
C3MR cycle
Liquefied Natural Gas (LNG)
Techno-economic assessment
Aspen HYSYS simulation
Process optimization
Sensitivity analysis
Subjects

Article Title Persian

تحلیل فنی-اقتصادی و تحلیل حساسیت فرآیند مایع‌سازی گاز طبیعی با استفاده از چرخه مبرد مخلوط پیش‌سردشده با پروپان

Authors Persian

سحر عرش تبار 1
مجتبی بیگلری 2
محمد صادق ولی پور 3
1 دانشجوی دکترا، دانشکده مهندسی مکانیک، دانشگاه سمنان، سمنان، ایران
2 دانشیار، دانشکده مهندسی مکانیک، دانشگاه سمنان، سمنان، ایران
3 استاد، دانشکده مهندسی مکانیک، دانشگاه سمنان، سمنان، ایران
Abstract Persian

گاز طبیعی مایع‌شده نقش اساسی در گذار جهانی انرژی ایفا می‌کند، زیرا امکان انتقال گاز طبیعی در مسافت‌های طولانی را با میزان انتشار آلاینده کمتر فراهم می‌سازد. ازاین‌رو، بهبود بازده انرژی و امکان‌پذیری اقتصادی فرآیندهای مایع‌سازی گاز طبیعی اهمیت ویژه‌ای دارد. در این پژوهش، یک تحلیل جامع فنی–اقتصادی به‌همراه ارزیابی حساسیت فرآیند مایع‌سازی گاز طبیعی با استفاده از چرخه مبرد مخلوط پیش‌سردشده با پروپان ارائه شده است. یک شبیه‌سازی حالت پایا در نرم‌افزار اسپن هایسیس نسخه ۱۲ توسعه داده شد و برای مدل‌سازی دقیق رفتار برودتی جریان‌های چندجزئی از معادله حالت پنگ–رابینسون استفاده گردید. فرآیند به دو زیرسامانه یکپارچه شامل پیش‌سردسازی با پروپان و زیرسردسازی با مبرد مخلوط تقسیم شد و عملکرد آن با استفاده از شاخص‌های کلیدی نظیر مصرف انرژی، نیاز توان الکتریکی و انتشار غیرمستقیم دی‌اکسید کربن ارزیابی گردید.
نتایج نشان می‌دهد که اگرچه چرخه مبرد مخلوط به توان الکتریکی اندکی بیشتر نسبت به مرحله پیش‌سردسازی با پروپان نیاز دارد، اما منجر به کاهش مصرف کل انرژی، کاهش نیاز به آب خنک‌کننده و کاهش قابل‌توجه انتشار آلاینده‌های زیست‌محیطی می‌شود. از منظر اقتصادی، برآورد هزینه‌ها بر اساس شاخص‌های به‌روز هزینه تجهیزات فرایندی بیانگر آن است که این بهبودهای فنی به عملکرد مالی مطلوبی منجر شده و با سودآوری بالا و دوره بازگشت سرمایه کوتاه در شرایط متعارف بازار گاز طبیعی مایع‌شده همراه است. تحلیل حساسیت همچنین نشان می‌دهد که نرخ‌های بالاتر خوراک گاز طبیعی، دبی‌های متوسط مبرد و فشار ورودی نزدیک به ۶۵ بار، بهترین توازن میان بازده انرژی و بازده اقتصادی را فراهم می‌کنند. در مجموع، یافته‌های این پژوهش تأیید می‌کند که چرخه مبرد مخلوط پیش‌سردشده با پروپان گزینه‌ای کارآمد و عملی برای تولید گاز طبیعی مایع‌شده در مقیاس بزرگ است و به‌طور مؤثری بهبود عملکرد ترمودینامیکی را با نتایج اقتصادی مطلوب پیوند می‌دهد.

Keywords Persian

چرخه مبرد مخلوط پیش‌سردشده با پروپان
گاز طبیعی مایع‌شده
ارزیابی فنی-اقتصادی
شبیه‌سازی فرایندی
بهینه‌سازی فرایند
تحلیل حساسیت
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Journal of Gas Technology
Volume 10, Issue 1 - Serial Number 14
September 2025
Pages 22-41