- 期刊
製造新型十碳環烷烴溶劑的芳香烴加氫製程之探討
On the Hydroprocessing for Production of Novel C10 Naphthenic Solvents
摘要
常用的芳香經溶劑，因高毒性，漸不容於日趨嚴謹的環保規範，而目前常見的不含芳香經環保溶劑，大都以烷烴及環烷烴類為主要組成。因這些環保溶劑含大量溶解效應不佳的烷烴成分，它們的溶解效應迥異於芳香經溶劑，無法直接取代後者。為此煉油及石化業積極探討如何合時宜地製造出新型具高溶解效應的非芳香經溶劑。十碳芳香經成分是煉油廠常見的產物，但它們當高沸點汽油成分來摻配的去化管道，也因空污效應而日愈萎縮，而目前轉移它們當高價位石化產品的新應用也從缺。因此，一些有多餘氫氣之煉油廠，正衡量以加氫處理方式，將十碳芳香烴產物轉化成非芳香烴型石化產品的可行性。我們以十碳芳香經為原料進行加氫製程之探討，預期將其完全轉化為環烷烴產物，當新型環保溶劑使用。 本製程探討分別使用自製的一個含白金已深度除鋁的Y沸石觸媒和另一個商用之Pt/Pd雙金屬觸媒，來加氫處理(1)純四甲基苯混合物、(2)對－二乙基苯、(3)芳香烴草取工場之含十碳芳香經油料、和(4) A150芳香經溶劑等4種進料，其製程條件為800 psig H2，220~320℃和LHSV 1。結果顯示芳香烴成分烴加氫飽和後，C10。環烷產物會隨反應溫度的升高，及觸媒酸活性之增加，而加速單環或雙環環烷烴上的烷基位移異構化反應。如反應激烈度再提昇，則會出現加氫開環反應，將部分環烷烴成分轉化為同碳數的烷烴，或裂解成低碳數之環烷烴及烷烴物。 製程探討的結果顯示C10加氫產物中溶解效應最佳者為雙環環烷烴類，多支鍵之環烷烴次之，烷烴類最差。因為煉油廠芳香經工場C10油料的加氫產物成分複雜，我們簡易地測量其密度來追蹤並評估產物中雙環環烷烴、單環環烷烴、及烷烴等成分的綜合溶解效應。我們探討的加氫製程之新產物的溶解效應，優於沸點相似的常見環保溶劑D40。
並列摘要
Globally, aromatic solvents (AS) are gradually being phased out by the stringent environmental mandates due to high toxicity. Common enviro-friendly hydrocarbon solvents (EFHS) are mostly made of paraffins and naphthenes. The solvency of paraffins is much inferior to that of aromatics, thus, the EFHS cannot directly substitute the AS in use. Petroleum and petrochemical refining industries are actively pursuing cost-effective means of producing new EFHS with better solvency. C19 aromatics are refining product commonly blended in minute amounts into gasoline pool. However, due to ill emission in combustion, this prevalent usage is gradually being regulated, presently its value-added new usage is lacking. Thus, for a few refiners with excess hydrogen, hydroprocessing of C10 aromatic streams to produce non-aromatic marketable products are being seriously considered and evaluated. We are exploring hydroprocessing of C10 aromatic streams as a means to making new EFHS. We used a lab-made, severely de-aluminated Y zeolite supported Pt catalyst, and a commercial Pt/Pd bimetallic catalyst to hydrogenate four different charge stocks: (1). a durene mixture, (2). p-diethylbenzene, (3). a C10(superscript +) aromatic product stream from aromatic extraction plant, (4). A150 aromatic solvent, using reaction conditions of 800 psig H2, 220-320℃, and LHSV 1. The results indicated that, upon aromatic saturation, the C10 naphthenic products enhance the isomerization rate of alkyl shift with increasing reaction temperature and with increasing catalyst acidity. With further increase of reaction severity (e.g., higher temperatures), partial naphthenic ring opening occurs, and results in producing paraffinic products with the same carbon numbers, and forming some paraffinic cracked products. The results also revealed that, among the C10 hydrogenated products, the bi-nuclear naphthenes exhibit the best solvency, the multiply branched mononuclear naphthenes the second, and paraffins the worst. For easy evaluation of the complicated refining streams, the specific gravity of the hydrogenated products were measured to correlate with their solvency characteristics. It showed that our processing conditions produce a C10(superscript +) hydrogenated product exhibiting better solvency than that of the commercial D40 grade EFHS with similar boiling range.