利用含水酒精與異丁烯於催化蒸餾塔生產環保型汽油添加劑之製程模擬

Process Simulation for Production of Environmentally Friendly Gasoline Additives by Using Hydrous Alcohol and Isobutene via Catalytic Distillation Column

陳厚岑(Hou-Tsen Chen) ； 林棕斌(Tsong-Bin Lin) ； 張志成(June-Cheng Chang) ； 賴宗成(Chong-Chien Lai)

《石油季刊》 54卷1期 (2018/03) Pp. 23-34

摘要

汽油添加劑主要用途為提高汽油辛烷值與含氧量，增加汽油燃燒效率、降低一氧化碳排放量並減少引擎爆震(detonation)現象，在台灣已廣泛使用甲基第三丁基醚(Methyl Tert-Butyl Ether, MTBE)添加於無鉛汽油以提高辛烷值。但近幾年有研究發現MTBE為潛在的化學致癌物質，對人體健康造成威脅。屬於清潔燃料的乙醇被視為MTBE替代品之一，然而當環境溫度下降時會出現汽油與酒精分離的現象，輕則降低燃燒效率，嚴重時將損壞引擎內部元件。另一方面，乙基第三丁基醚(Ethyl Tert-Butyl Ether, ETBE)與第三丁醇(Tertiary Butyl Alcohol, TBA)則因燃燒特性接近MTBE、具環境友善性及低水溶性，被視為具市場潛力之汽油添加劑。本研究提出利用90 wt%含水酒精與煉油廠四碳烴餾分中的異丁烯於催化蒸餾塔進行反應之製程模擬，結果顯示於塔底可取得含水量低於0.5 wt%之乙醇、乙基第三丁基醚與異丁醇混合物流，其優勢為不需高度純化進料與產物，且可於煉廠直接與汽油摻配。

關鍵字

催化蒸餾 ； 乙醇 ； 乙基第三丁基醚 ； 異丁醇

並列摘要

The main purposes of gasoline additives are to improve the octane number and oxygen content of gasoline, to increase gasoline combustion efficiency, to decline carbon monoxide emissions and to reduce the engine detonation. In Taiwan, methyl tert-butyl ether (MTBE) has been widely added to unleaded gasoline to enhance octane number. However, in recent years some studies have revealed that MTBE is a carcinogenic substance which threatens human health. Ethanol, which is a clean fuel, is considered as one of MTBE alternatives. But the separation of gasoline and alcohol caused by temperature drop will result in lower combustion efficiency and severer damage to internal parts of the engine. On the other hand, both ethyl tert-butyl ether, ETBE) and tertiary butyl alcohol (TBA) which have similar combustion characteristics to MTBE, but more environmentally friendly and low water solubility make them regarded as marketing potential gasoline additives. In this article, a simulation process where the hydrous alcohol stream with 90 wt% of ethanol reacts with isobutene in the C4 fractions from refinery via catalytic distillation is studied. The result shows a mixture stream contains ethanol, ETBE, TBA and less than 0.5 wt% of water is achieved from the bottom of catalytic distillation. The advantages of this process are that the feedstock and product are not required to be highly purified and the product can be mixed with gasoline directly in the refinery.

並列關鍵字

Catalytic Distillation ； Ethanol ； Ethyl Tert-Butyl Ether ； Tertiary Butyl Alcohol