Enhancement of Ternary LNG Mixture Separation Process by using Dividing Wall Column

Document Type : Original Article

Authors
Mahmoud Hemmati 1
Morteza Zivdar 2
Taleb Zarei 3
Rahbar Rahimi 2
1 Ph.D. Student, Department of Chemical Engineering, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
2 Professor, Department of Chemical Engineering, Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran
3 Professor, Department of Mechanical Engineering, University of Hormozgan, Bandar Abbas, Iran
20.1001.1/jgt.2026.2076264.1063
Abstract
The dividing wall column (DWC) represents a form of process intensification that offers the potential to lower energy usage and initial investment costs in distillation practices. This research undertakes a systematic optimization and economic comparison between DWC and a traditional distillation column process for the separation of a three-component mixture of N-Pentane, N-Hexane, and N-Heptane. The analysis delves into the exergy flows and economic aspects of these two processes in detail. In this study the sequential quadratic programming (SQP) optimization method was used to minimize the total reboiler and condenser duties and the Peng Robinson model is applied to predict the vapor-liquid equilibrium (VLE) of the systems under study. In this study, DWC is evaluated against a conventional two-column distillation setup in terms of total annual cost (TAC) and energy consumption under the same feed ratio conditions. The results show that implementing DWC leads to a 37% decrease in TAC and a 38% reduction in energy requirements. This research proposes the use of dividing wall columns as an alternative to traditional distillation columns, providing a new method for separating hydrocarbons that emphasizes economic efficiency and encourages the adoption of innovative practices for energy conservation and environmental protection.
Keywords
Dividing wall column
Optimization
Aspen plus
Total Annual Cost
Energy Efficiency
Ternary Hydrocarbon Separation
Process Intensification
Subjects

Article Title Persian

بهبود جداسازی یک مخلوط سه جزئی هیدروکربنی با استفاده از برج تقطیر دیوار میانی

Authors Persian

محمود همتی 1
مرتضی زیودار 2
طالب زارعی 3
رهبر رحیمی 2
1 دانشجوی دکترا، گروه مهندسی شیمی، دانشکده مهندسی، دانشگاه سیستان و بلوچستان، زاهدان، ایران
2 استاد، گروه مهندسی شیمی، دانشکده مهندسی، دانشگاه سیستان و بلوچستان، زاهدان، ایران
3 استاد، گروه مهندسی مکانیک، دانشگاه هرمزگان، بندرعباس، ایران
Abstract Persian

برج تقطیر دیوار میانی (DWC) به‌عنوان یکی از راهکارهای پیشرفته در تشدید فرآیند، پتانسیل بالایی برای کاهش مصرف انرژی و هزینه‌های سرمایه‌گذاری اولیه در سیستم‌های تقطیر دارد. این مطالعه با هدف بهینه‌سازی سیستماتیک و مقایسه اقتصادی، عملکرد برج تقطیر دیوار میانی را در مقایسه با فرآیند تقطیر متداول برای جداسازی مخلوط سه‌جزئی نرمال‌پنتان، هگزان و هپتان ارزیابی می‌کند. در این راستا، تحلیل جریان‌های اگزرژی و ابعاد اقتصادی هر دو فرآیند به‌تفصیل بررسی شده است. به‌منظور کمینه‌سازی مجموع بارهای حرارتی ریبویلر و کندانسور، از روش بهینه‌سازی «برنامه‌ریزی درجه دوم متوالی» (SQP) استفاده و برای پیش‌بینی تعادل بخار-مایع (VLE) سیستم، مدل ترمودینامیکی پنگ-رابینسون به کار گرفته شد. درنهایت، با در نظر گرفتن شرایط یکسان خوراک، عملکرد برج تقطیر دیوار میانی در مقایسه با سیستم تقطیر دو ستونی مرسوم، از نظر کل هزینه سالانه و مصرف انرژی سنجیده شد. نتایج نشان می‌دهد که به‌کارگیری برج تقطیر دیوار میانی منجر به ۳۷ درصد کاهش در کل هزینه سالانه و ۳۸ درصد کاهش در مصرف انرژی می‌شود. در مجموع، این پژوهش ضمن تأکید بر بهره‌وری اقتصادی و راهکارهای نوآورانه در بهینه‌سازی مصرف انرژی و حفاظت از محیط‌زیست، استفاده از ستون‌های دیواره جداکننده را به‌عنوان جایگزینی کارآمد و عملیاتی برای برج‌های تقطیر متوالی پیشنهاد می‌کند.

Keywords Persian

برج دیوار میانی
بهینه‌سازی
جداسازی مخلوط سه جزئی
کل هزینه سالانه
بازدهی انرژی
تشدید فرآیند
اسپن پلاس
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