• 作者： Chen, Hsi-Jen; Chen, Chao-Yu
• 中文摘要： 熱裂技術是目前石化工業產製烯烴的主要方法。隨石化工業的發展丙烯的需求量與日俱增,這種需求僅次於乙烯的石化基本原料,由於過去丙烯的產製可說是伴隨乙烯的聯產物,所以丙烯產量不高。因此獨立於乙烯以生產丙烯為主的製程可能有其必要性,異丁烷是具有相當吸引力的裂解進料,因為除丙烯外,異丁烷裂解尚可得到異丁烯。以異丁烯為原料與甲醇反應生成的甲基第三丁基醚(MTBE),為目前汽油中所摻配的重要含氧燃料油。隨著環保意識抬頭與汽油的無鉛化促使MTBE辛烷值提昇劑需求量大增,連帶使異丁烯的需要量增加。異丁烷因其分子結構關係,在碳氫油料中最能兼顧到丙烯與異丁烯的聯產。本文提出以異丁烷為裂解進料,便是以增產丙烯與異丁烯產能為目的,針對裂解反應器提出一套符合設計理念的數學模式,模式中考慮異丁烷裂解主要反應的動力學、管式反應器內各裂解氣成分之質量結算、反應器內的能量結算以及反應器熱傳遞現象(包括裂解爐的輻射與爐管的熱傳導、熱對流),模式中亦考慮機械能均衡以求模式之完整性。透過此數學模式的建立,配合數值分析與模擬,以期對異丁烷裂解後產物的分布有合理的預測。此外,藉此模式亦探討最適產率之操作變數。
• 英文摘要： The pyrolysis technique is a prime method for production of olefins in the petrochemical industry today. Due to the rapidly growing demand for propylene, there may be a need for processes producing propylene independently from ethylene. Isobutane is an attractive feedstock for cracking because isobutene is also produced in addition to propylene. Isobutene and methanol react to form methyl tert- butyl ether (MTBE). It is an important oxygenated gasoline with a high octane number. At present the market requirements of MTBE are skyrocketing as a result of environmental consciousness. The molecular structure of isobutane tends to produce high yield of propylene and isobutene among most of hydrocarbon feedstocks. This paper deals with a mathematical model of the cracking reactor. In the model, isobutane reaction kinetics, material/energy balance of cracked gases, heat transfer mechanisms such as radiation in the cracking furnace, heat conduction and convection of tube, pressure drop across the tubular reactor are all considered. The model leads to a set of nonlinear ordinary differential equations, including thirteen cracked- gas mass balances plus overall energy and pressure drop differential equations. By means of the model, we are able to solve and predict product distribution in the exit coil numerically. In addition, we can take advantage of this model by selecting proper operating parameters and thus obtain optimal product yields.
• 中文關鍵字： 熱解; 裂解; 模式; 異丁烷; 丙烯; 異丁烯
• 英文關鍵字： Pyrolysis; Cracker; Model; Isobutane; Propylene; Isobutene