ENERGY EFFICIENT DISTILLATION COLUMNS SEQUENCE FOR HYDROCARBON MIXTURES FRACTIONATION PROCESS MOHAMAD FIRDAUS BIN AZIZAN

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1 i ENERGY EFFICIENT DISTILLATION COLUMNS SEQUENCE FOR HYDROCARBON MIXTURES FRACTIONATION PROCESS MOHAMAD FIRDAUS BIN AZIZAN A thesis submitted in fulfilment of the requirements for the award the degree of Bachelor of Engineering (Chemical) Faculty of Chemical Engineering Universiti Teknologi Malaysia January 2015

2 v ABSTRACT The objective of this research is to develop a systematic methodology of energy efficient distillation columns sequence for the hydrocarbon mixtures (HM) fractionation process by using driving force method. To perform the study and analysis, the energy efficient HM fractionation plant methodology is developed. In the first step, a simple and reliable short-cut method of process simulator (Aspen HYSYS) is used to simulate a base (existing) HM sequence. The energy used to recover individual fractions in the base sequence is analyzed and taken as a reference. In the second stage, an optimal HM sequence is determined by using driving force method. All individual driving force curves for all adjacent components are plotted and the optimal sequence is determined based on the plotted driving force curves. Once the optimal HM sequence has been determined, the new optimal sequence is then simulated in step three using a simple and reliable short-cut method (using Aspen HYSYS), where the energy used in the optimal HM sequence is analyzed. Finally, the energy used in the optimal HM sequence is compared with the base sequence. The return of investment (ROI) and simple payback period are also calculated. Several case studies have been used to test the performance of the developed methodology. A maximum energy saving of 40 % was achieved when compared the optimal (driving force) sequence with the existing direct sequence. The ROI of 3 was obtained with 4 month of payback period. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for HM fractionation process. All of this findings show that the methodology is able to design minimum energy distillation column sequence for HM fractionation process in an easy, practical and systematic manner.

3 vi ABSTRAK Objektif kajian ini adalah untuk membangunkan satu kaedah yang sistematik tenaga effisien urutan ruangan penyulingan untuk proses pembahagian campuran hidrokarbon (HM), dengan menggunakan kaedah daya penggerak. Untuk melaksanakan kajian dan analisis, metodologi tenaga effisien loji pemisahan HM dirangkakan. Dalam langkah pertama, kaedah pintas mudah dan boleh dipercayai dalam proses simulator (Aspen HYSYS) digunakan untuk mensimulasikan asas (sedia ada) urutan HM. Tenaga yang digunakan untuk mendapatkan semula pecahan individu dalam urutan asas dianalisis dan diambil sebagai rujukan. Pada peringkat kedua, urutan HM optimum ditentukan dengan menggunakan kaedah daya penggerak. Semua lengkungan daya penggerak untuk semua komponen bersebelahan diplot dan urutan optimum ditentukan berdasarkan lengkung itu tadi. Setelah urutan HM optimum telah ditentukan, urutan optimum baru kemudian disimulasi dalam langkah tiga dengan menggunakan satu kaedah pintas yang mudah dan boleh dipercayai (Aspen HYSYS), di mana tenaga yang digunakan dalam urutan HM optimum dianalisis. Akhirnya, tenaga yang digunakan dalam urutan HM optimum dibandingkan dengan urutan asas. Pulangan pelaburan (ROI) dan tempoh bayaran balik (PBP) juga dikira. Beberapa kajian kes telah digunakan untuk menguji prestasi metodologi yang dibangunkan. 40% Penjimatan tenaga maksimum telah dicapai apabila urutan optimum dibandingkan dengan urutan langsung yang sedia ada. ROI sebanyak nilai 3 telah diperolehi dengan 4 bulan tempoh bayar balik. Oleh itu, dapat disimpulkan bahawa, urutan yang ditentukan oleh kaedah daya penggerak dapat mengurangkan tenaga yang digunakan untuk proses pemisahan HM. Semua penemuan ini menunjukkan bahawa kaedah ini mampu untuk mereka bentuk tenaga minimum penyulingan urutan ruangan untuk proses pemisahan HM dengan cara yang mudah, praktikal dan sistematik.

4 55 REFERENCES Bek-Pedersen, E., & Gani, R. (2004). Design and synthesis of distillation systems using a driving-force-based approach. Chemical Engineering And Processing: Process Intensification, 43(3), doi: /s (03)00120-x Errico, M., Rong, B., Torres-Ortega, C., & Segovia-Hernandez, J. (2014). The importance of the sequential synthesis methodology in the optimal distillation sequences design. Computers & Chemical Engineering, 62, 1-9. doi: /j.compchemeng Fidkowski, Z., Malone, M., & Taylor, R. (2008). Perry's Chemical Engineers' Handbook. Section 13. McGraw-Hill Pub. Forbes, R. (1970). A short history of the art of distillation. Leiden: E.J. Brill. Gadkari, P., & Govind, R. (1988). Analytical screening criterion for sequencing of distillation columns. Computers & Chemical Engineering, 12(12), doi: / (88) Genereaux, R. (1937). Fluid-Flow Design Methods. Ind. Eng. Chem., 29(4), doi: /ie50328a007 Giridhar, A., & Agrawal, R. (2010). Synthesis of distillation configurations: I. Characteristics of a good search space. Computers & Chemical Engineering, 34(1), doi: /j.compchemeng Heaven, B. (1969). The manufacturing problem. Production Engineer, 48(7), 311. doi: /tpe

5 56 Hernandez, S., Gabrielsegoviahernandez, J., & Ricoramirez, V. (2006). Thermodynamically equivalent distillation schemes to the Petlyuk column for ternary mixtures. Energy, 31(12), doi: /j.energy Libavius, A., & Rex, F. (1964). Die Alchemie des Andreas Libavius (Alchemia, dt.) Ein Lehrbuch d. Chemie aus d. Jahre Mascia, M., Ferrara, F., Vacca, A., Tola, G., & Errico, M. (2007). Design of heat integrated distillation systems for a light ends separation plant. Applied Thermal Engineering, 27(7), doi: /j.applthermaleng Modi, A., & Westerberg, A. (1992). Distillation column sequencing using marginal price. Industrial & Engineering Chemistry Research, 31(3), doi: /ie00003a028 Nadgir, V., & Liu, Y. (1983). Studies in chemical process design and synthesis: Part V: A simple heuristic method for systematic synthesis of initial sequences for multicomponent separations. Aiche J., 29(6), doi: /aic Nath, R., & Motard, R. (1981). Evolutionary synthesis of separation processes. Aiche J., 27(4), doi: /aic Porter, K., & Momoh, S. (1991). Finding the optimum sequence of distillation columns - an equation to replace the â œrules of thumbâ (heuristics). The Chemical Engineering Journal, 46(3), doi: / (91)87001-q Schaller, M., Hoffmann, K., Siragusa, G., Salamon, P., & Andresen, B. (2001). Numerically optimized performance of diabatic distillation columns. Computers & Chemical Engineering, 25(11-12), doi: /s (01) Seader, J., & Westerberg, A. (1977). A combined heuristic and evolutionary strategy for synthesis of simple separation sequences. Aiche J., 23(6), doi: /aic

6 57 Seader, J., & Westerberg, A. (1977). A combined heuristic and evolutionary strategy for synthesis of simple separation sequences. Aiche J., 23(6), doi: /aic Seider, W., Seader, J., Lewin, D., & Seider, W. (2004). Product and process design principles. New York: Wiley. Steyermark, A. (1983). Kirk-Othmer encyclopedia of chemical technology, vol. 17 (including index to vols. 13 to 16), 3rd ed. Microchemical Journal, 28(1), 150. doi: / x(83)