بررسی عوامل اثرگذار بر تشکیل ذرات پودر ریز در فرایند تولید پلی‌اتیلن پرچگالی

نوع مقاله : تالیفی

نویسندگان

1 تحقیق و توسعه پتروشیمی جم

2 پژوهشگاه پلیمر و پتروشیمی ایران، پژوهشکده مهندسی

3 عضو هیئت علمی پژوهشگاه پلیمر

چکیده

کنترل شکل ­شناسی از مسائل مهم در توسعه صنایع کاتالیزی در فرایند تولید پلی‌اتیلن است. نسل‌های جدید کاتالیزگرهای تولید پلی­ اولفین­ ها رفتارهای متفاوتی طی فرایند قطعه­ قطعه ­شدن نشان می‌دهند. طی لحظات اولیه پلیمرشدن، با نفوذ سریع مونومر گازی اتیلن به درون حفره ­های کاتالیزگر، در کاتالیزگرهای با استحکام مکانیکی کم، قطعه ­قطعه شدن رخ می­ دهد که سبب تشکیل ذرات ریز می ­شود. از سویی، ممکن است ذرات تشکیل­ شده در حین فرایند پلیمرشدن طی هم­زدن در اثر برخورد به یکدیگر، همزن یا دیواره واکنشگاه شکسته شده و ذرات کمتر از اندازه استاندارد تولید شوند. این ذرات با اندازه کمتر از حد معمول (µm 63 >) تحت عنوان پودر ریز شناخته می‌شوند. وجود ذرات پودر ریز از معضلات مهم در صنعت پلی­ اولفین ­ها، به­ ویژه پلی‌اتیلن است و موجب بروز مشکلاتی از جمله تشکیل لایه روی دیواره واکنشگاه و نقاط داغ، ایجاد گرفتگی در واکنشگاه های فاز گازی و تجهیزات جانبی نظیر مبدل‌های گرما، پمپ‌ها، خشک‌کن‌ها و تولید محصولات نامطلوب خارج از استاندارد می‌شوند. امروزه در صنعت پلی ­اولفین ­ها همواره به دنبال راهی برای کاهش مقدار تشکیل ذرات پودر ریز در فرایند پلیمرشدن هستند. در این مقاله با توجه به اهمیت این موضوع، به عوامل مهم تشکیل این ذرات شامل عوامل فرایندی و کاتالیزی پرداخته می‌شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation of factors affecting fine formation in high density polyethylene production process

نویسندگان [English]

  • hossein bazgir 1
  • reza rashedi 1
  • zahra isaabade 2
  • naeimeh bahri-laleh 3
1 Research and Development Center, Jam Petrochemical Company, Assaluyeh, Boushehr, Iran
2 Department of Polymerization Engineering, Iran Polymer and Petrochemical Institute (IPPI), Tehran, Iran.
3 academic staff in IPPI
چکیده [English]

Morphological control is one of the important issues in the development of catalysis industries in the polyethylene production process. New generations of catalysts for the production of polyolefins exhibit different behaviors during the fragmentation process. In the initial stages of polymerization, fragmentation occurs with the rapid penetration of ethylene monomer into the pores of catalyst with low mechanical strength, which causes the formation of fine particles. On the other hand, particles formed during the polymerization process may be broken due to collision with each other, the stirrer or the wall of the reactor, and particles smaller than the standard size can be produced. In the case of catalysts with low mechanical strength, the formation of fine particles would occur considerably. These particles with a smaller size than usual (>63 µm) are known as fine powder. The presence of fine powder particles is one of the important problems in the polyolefin industry, especially polyethylene, and causes problems such as the formation of a layer on the reactor wall and hot spots, clogging in the gas phase reactors and peripheral equipment such as heat exchangers, pumps, dryers, and the production of undesirable and non-standard products. Today, in the polyolefin industry, they are always looking for a way to reduce the amount of fine powder particles in the polymerization process. In this article, due to the importance of this issue, substantial factors of the formation of these particles, including process and catalysis factors are discussed.

کلیدواژه‌ها [English]

  • Ziegler-Natta catalyst
  • High Density Polyethylene
  • Fine particles
  • polymerization
  • polyolefin
1.  Ziegler K., Holzkamp E., Breil H., and Martin H., Polymerisa-tion Von Äthylen Und Anderen Olefnen, Angew. Chemie, 67, 426, 1955.
2.  Chammingkwan P., Wannaborworn M., Terano M., Taniike T., and Phiriyawirut P., Particle Engineering of Magnesium 
Ethoxide-Based Ziegler-Natta Catalys through Pos-Modi-fcation of Magnesium Ethoxide, Appl. Catal. A: Gen., 626, 
118337, 2021.
3.  Mohamadi Z., Moradi G., and Teimoury H.R., Comparison of Mg-Ethoxide Based Ziegler Natta Catalyss Using Diferent 
Internal Donors Employed for Ethylene Polymerization,  J. Polym. Res., 28, 1-10, 2021.
4.  Jiang B., Ye J., Liao Z., Shi X., Huang Z., Wang J., and Yang Y., Experimental Invesigation on Mechanisms of Fine 
Particles Generation for the Borealis Borsar Multisage Olefn Polymerization Process, J. Appl. Polym. Sci., 135, 46589, 2018
.5.  Fisch A.G., dos Santos J.H.Z., Secchi A.R., and Cardozo N.S.M., Heterogeneous Catalyss for Olefn Polymerization: 
Mathematical Model for Catalys Particle Fragmentation, Ind. Eng. Chem. Res.,  54, 11997-12010, 2015.
6.  Banat Y.,  Fines Generation in Gas-Phase Ethylene Polymerization, Ph.D Thesis-Research UT, Graduation UT, 
2006.
7.  Martins A.R., Cancelas A.J., and McKenna T.F.L., A Study of the Gas Phase Polymerization of Propylene: The Impact 
of Catalys Treatment, Injection Conditions and the Presence of Alkanes on Polymerization and Polymer Properties, 
Macromol. React. Eng.,  11, 1600011, 2017.
8.  Chen J., Catalys Component for Ethene Polymerization and Catalys Thereof,  Chinese Pat.  CN102344514, 2010.
9.  Fisch A.G., Efects of the Ethoxide in the Coordination Sphere of Titanium on the Performance of MgCl2
-Based Ziegler–Natta Catalys,  Ind. Eng. Chem. Res.,  57, 6141-6152, 2018.
10. Friedhelm G. and Schneider S., Catalys Components for the Polymerization of Olefns and Catalyss Therefrom Obtained, EP Pat. EP2582731B1, 2011.
11. Seifali Abbas-Abadi M., The Production of High Efciency Ziegler–Natta Catalys with Dual Active Sites Nature Using 
Cyclohexyl Chloride as Promoter With Super Activity and Produced Superior Polyethylene with Controllable Molecular 
Weight Disribution,  Des. Monomers Polym.,  20, 524-531, 2017.
12  McKenna T.F.L., Growth and Evolution of Particle Morphology: An Experimental and Modelling Study, Macromol. Symp., 65-73, 2007.
13. Alves R.F., Casalini T., Storti G., McKenna T.F.L., Gas‐Phase Polyethylene Reactors—A Critical Review of Modeling 
Approaches, Macromol. React. Eng., 2000059, 2021.
14. Zhou Y., Zhang R., Ren H., He X., Liu B., Zhao N., and Liu B., Ethylene Polymerization over Novel Organic Magnesium 
Based V/Ti Bimetallic Ziegler-Natta Catalyss, J. Organomet. Chem., 908, 121066, 2020.
15. Bahri-Laleh N., Nekoomanesh-Haghighi M., Mirmohammadi S.A., A DFT Study on the Efect of Hydrogen in Ethylene and Propylene Polymerization Using a Ti-Based Heterogeneous Ziegler–Natta Catalys,  J. Organomet. Chem.,  719, 74-79, 
2012.
16. Alt F.P., Böhm L.L., Enderle H., and Berthold J., Bimodal Polyethylene–Interplay of Catalys and Process,  Macromol. 
Symp., 135-144, 2001.
17. Akram M.A., Liu X., Jiang B., Zhang B., Ali A., Fu Z., and Fan Z., Efect of Alkylaluminum Cocatalys on Ethylene/1-
Hexene Copolymerization and Active Center Disribution of MgCl2-Supported Ziegler-Natta Catalys,  J. Macromol. Sci. 
Part A, 1–11, 2021.
18. Zhang H., Lee Y., Park J., Lee D., and Yoon K., Control of Molecular Weight Disribution for Polypropylene Obtained by 
a Commercial Ziegler–Natta Catalys: Efect of a Cocatalys and Hydrogen, J. Appl. Polym. Sci., 120, 101-108, 2011.
19. Fallah M., Bahri‐Laleh N., Didehban K., and Poater A., Interaction of Common Cocatalyss in Ziegler–Natta‐Catalyzed 
Olefn Polymerization,  Appl. Organomet. Chem.,  34, e5333, 2020.
 20.  Fernandes F.A.N. and Lona L.M.F., Fluidized Bed Reactor for Polyethylene Production. the Infuence of Polyethylene 
Prepolymerization,  Brazilian J. Chem. Eng.,  17, 163-170, 2000.
21. Yang Y., Zou X., Xiao F., and Dong H., Integrated Product-Process Design Approach for Polyethylene Productio, Chem. 
Eng. Trans., 61, 1009-1014, 2017.
22. Ghafelebashi Zaranda S.M. and Safnejad A., Determination of Kinetic Parameters for Ethylene Polymerization (with and Without Hydrogen) by Ziegler-Natta Catalys, Polyolefns J., 7, 121-130, 2020.
23. Chen K., Mehdiabadi S., Liu B., and Soares J.B.P., Esimation of Apparent Kinetic Consants of Individual Site Types for the Polymerization of Ethylene and Α‐Olefns with Ziegler–Natta Catalyss, Macromol. React. Eng., 10, 551-566, 2016.
24. Owi W. and Chen U., Catalys Component for Ethene Polymerization and       Catalys Thereof,     Chinese Pat. N102344514A, 2010.
25. Thomas F.A., Andre F., and Dominique J., Polyolefn Powder, EP Pat. EP2021385B, 2006.
26. Stephan D. and Dominique J., Process for the Polymerization of Olefns, EP Pat. EP1660546A1, 2003.
27. Niclasina S. and Johanna A., Polyethylene Homo- or Copolymer Having Improved Wear Properties, US Pat. US10144788B2, 2015.
28. Nicolaas H.F., Process for The Production of Polyethylene, WO Pat.  WO2010006756A1, 2010.
29. Visscher F., Guzman C., and Daniel G., Management of Polymer Fines in Multimodal Polyethylene Production, EP Pat. 
3510055B, 2020