頁岩天然氣凝析液於石化工業之製程研究：乙烯與醋酸乙烯單體

Process Research of Shale Natural Gas Liquid (NGL) in the Petrochemical Industry: Ethylene and Vinyl Acetate Monomer

沈坤榮(Kun-Rong Shen)

指導教授 ： 陳錫仁

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2016年)

https://doi.org/10.6846/TKU.2016.01004

摘要

近年頁岩氣的開採技術有所突破後，非傳統油氣資源的頁岩氣和頁岩油，又掀起一股全球油氣浪潮，其影響石化工業甚鉅。本研究以分離頁岩氣後所得之頁岩天然氣凝析液後從中分離出乙烷製造乙烯及其衍生物醋酸乙烯單體。
頁岩天然氣凝析液分離製程中，吾人採用蒸餾塔進行頁岩氣之分離，其中分離出之乙烷純度為97.1 mol%。乙烷進入乙烯製程中之裂解爐，透過加入低壓蒸汽於裂解爐中進行蒸汽裂解反應產生乙烯，再將乙烯、氧氣以及氣相醋酸作為進料進入管式觸媒反應器生產醋酸乙烯，管式觸媒反應器之操作條件在溫度150–165°C之間，壓力6.6 atm，內裝有1100根管子，其管長為10公尺，管徑為0.037公尺，以鍋爐飼水控制反應器溫度確保其不超過180°C，以避免觸媒變質劣化，同時也產生低壓蒸汽供製程使用；另外，由於醋酸乙烯反應器是高放熱氧化反應，其製程安全分析也在論文中提出。反應器之產物經共沸塔將醋酸從水和醋酸乙烯中分離出來，最後醋酸乙烯和水再進行純化到高純度之醋酸乙烯即為醋酸乙烯單體。在乙烷蒸汽裂解量產乙烯製程上，以乙烯年產量為十萬公噸、純度達99 mol%為設計目標；在醋酸乙烯單體製程上，以醋酸乙烯單體年產量為三萬公噸、純度達99 mol%為設計目標。值得一提的是在天然氣凝析液分離程序、乙烯的精餾以及醋酸乙烯單體之蒸餾塔設計乃利用吾人提出的「蒸
餾塔設計三部曲」做節能設計；此外，並針對醋酸乙烯單體製程進行熱能整合，以求有效達到節能省碳之目的。
本論文之主要應用 “Aspen Plus”與“SuperTarget”兩種化工程序軟體，前者用於程序合成與設計；後者則用於狹點分析及換熱器網路合成。

關鍵字

頁岩天然氣凝析液 ； 石化工業 ； 乙烯製程 ； 醋酸乙烯製程

並列摘要

Recently, since the breakthrough of shale gas mining technology, unconventional shale gas and shale oil resources set off a wave of global-oil-gas and hugely impact the petrochemical industry. The aim of this study is at the design of separating natural gas liquid (NGL) from shale gas. Then we separate ethane from the NGL as raw material for ethylene and, its derivative, vinyl acetate monomer (VAM).
In the NGL separation process, we have to use a train of distillation columns to separate shale gas. The 97.1 mol% purity of ethane enters the cracking furnace mixed with the low-pressure steam in order to produce ethylene. Ethylene, oxygen and vaporized acetic acid enter the tubular reactor which contains 1,100 tubes with 0.037 m in diameter and 10 m in length filled with catalyst. The operating pressure is set at 6.6 atm, and temperature between 150oC and 165oC. We use boiler feed water to keep the reactor temperature below 180oC to prevent the degradation of the catalyst while generating low-pressure-steam for process purpose. Additionally, due to its highly exothermic nature of oxidation reaction, process safety is also considered in the study. Azeotropic column separates acetic acid from vinyl acetate and water and further purified to obtain vinyl acetate monomer (VAM). This study designs a plant capacity of 100,000 metric tons per year of 99 mol% purity of ethylene and a plant capacity of 30,000 metric tons per year of 99 mol% purity of VAM. It is noteworthy that in regarding to the distillation columns, we use a “three-step design procedure” to minimize the reboiler’s heat duty and save the energy consumption. In addition, pinch technology is carried out to heat-integrate the plant-wide VAM process.
Two kinds of software are utilized in the research－Aspen Plus and SuperTarget. The first is applied to implement the process synthesis and design; the second is applied to perform the pinch analysis and the synthesis of heat exchanger network.

並列關鍵字

Natural Gas Liquid (NGL) ； Petrochemical Industry ； Ethylene Process ； Vinyl Acetate Process

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