異構化白金觸媒失活問題與解決

Isomerization of the Platinum Catalyst Deactivation Problems and Solutions

黃文龍(Wen-Long Hwang) ； 洪正宗(Cheng-Tsung Hong) ； 何德川(Te-Chuan Ho) ； 黃德湧(Teh-Yung Huang) ； 王秀芳(Shiow-Fang Wang) ； 何應昌(Ying-Shiang Ho) ； 廖本源(Ben-Yuan Liao) ； 賴源俊(Yuan-Jiunn Lay) ； 林博祥(Po-Shiaung Lin) ； 許信豐(Shin-Fang Shu)

《石油季刊》 48卷2期 (2012/06) Pp. 51-65

https://doi.org/10.30128/JP.201206.0005

摘要

中油公司輕石油腦異構化工場發生兩次白金觸媒性能失活問題，第一次是使用特殊輕質五碳烷烴（C5）油料，其所含硫化物高達4,000 ppm（工場設計最高為447 ppm）導致異構化工場加氫脫硫與保護裝置無法負荷，高濃度硫化氫貫穿異構化工場造成白金觸媒和分子篩中毒，產品辛烷值無法提昇，第二次是低濃度硫化氫洩漏造成白金觸媒中毒失活，異構化工場無法生產合格戊烷/己烷之汽油摻配輕質油料，導致每天必須自他廠以槽車運補C5/C6異構化油應急，嚴重影響中油公司汽油生產與調度。煉研所異構化研究小組與生產工廠技術與生產單位同仁共同探討白金觸媒性能失活問題與研議解決方案，執行結果如下所示︰一、 高濃度硫化物造成異構化白金觸媒與吸附分離製程分子篩中毒問題：1. 高達3,000 ppm 硫化氫貫穿異構化工場10 多座反應器（包括2 座白金觸媒和4 座分離製程分子篩），導致白金觸媒和吸附分離製程功能喪失，產品辛烷值無法提升。2. 由於更換新觸媒(白金觸媒)程序繁瑣，最快也要6個月後，時效性差，最後決議執行再生方案。3. 觸媒和分子篩活性再生方案執行結果︰中毒前異構化產品油異戊烷比例平均為68.9 %，中毒時只有35.8 %，再生後增加為71.94 %。中毒前產品辛烷值平均值 84.12，工場提昇輕石油腦產品辛烷值平均10.84 單位，觸媒再生後產品辛烷值平均值85.43，工場提昇輕石油腦產品辛烷值平均11.48 單位（比中毒前多提昇0.64 單位），顯示再生技術成功，觸媒和分子篩功能都已恢復且比中毒前功能更佳。二、 低濃度硫化物造成新換異構化白金觸媒中毒問題：1. 更換新異構化觸媒卻發現性能性能比舊觸媒差，由工場進料雜質分析、操作條件分析和工場PI 資料比對，都顯示工場一切操作條件都沒問題。2. 原設計公司只建議提高溫度，但是並未分析和告知觸媒性能不佳之原因，煉研所建議：提高反應溫度（提高觸媒活性）只是治標，應找出真正失活原因。3. 經一系列工場操作條件分析比對後，確認是白金觸媒中毒，再經過工場分段性能檢測後，終於找出微量硫化物在硫化氫保護床取樣側管處有些微洩漏問題。4. 應用再生技術使白金觸媒恢復功能，改善後異構化油產品油辛烷值由中毒時85 提高至90.5。三、 本研究將輕油異構化工場發生兩次白金觸媒性能失活問題與解決案例，提供給煉油與石化同業伙伴經驗共享，避免重蹈覆轍。

關鍵字

異構化 ； 觸媒 ； 失活

並列摘要

One of CPC light paraffin isomerization plant ever used a special C5 feedstock. Sulfur content of this fraction was 4,000 w ppm that was much higher than the designed condition (max 447 w ppm). The hydrodesulfurization and sulfur guard units of this plant were overloaded. H2S was break-through into the isomeration reactor to poison the Pt catalysts and into the Isosiv unit to poison the molecular sieves. As a consequence, there was no increase of octane number of the isomerate product. The product could not meet the specification of the gasoline blending component. CPC had to transport C5/C6 isomerate from kau-sheung refinery to the plant for production of on specification gasoline.To resolve the problem, there was a trouble-shooting team including the RMRI researchers plant technical staffs and operation staffs. As the catalyst supplier had no stock of prepared catalyst, it would take at least six months to manufacture a new batch fresh catalyst CPC wished to regenerate the poisoned catalyst. CPC decided to use the activation procedures to regenerate the poisoned catalyst, such as recycled of high purity and high flow rate of hydrogen at elevated temperatures to desorb the adsorbed hydrogen sulfide. Finally the activity of the sulfur poisoned catalysts was recovered.High concentration sulphide caused isomeration Pt catalyst and Isosiv molecular sieve poisoned. As high as 3,000 ppm hydrosulphide gas went through 10 units, (Including two Pt catalyst reactors and four molecular sieve adsorption separation units) that caused isomeration Pt catalyst and Isosiv molecular sieve poisoned and the octane number of product was unqualified. It would take at least six months to change a new batch fresh catalyst, so CPC decided to use the activation procedure to regenerate the poisoned catalyst. The percentage of isopantane decreased from 68.9% to 35.8% by poisoning and increased to 71.94% by regeneration. The Octane number decreased about 10.84 units by poisoning and recovered the loss and gained another 0.64 units by regeneration. Both catalyst and molecular sieve performance were much better after regeneration when being poisoned.Low concentration sulphide causes newly changed isomeration Pt catalyst poisoned.Trace of hydrosulphide leaked from guard chamber sampling tube. It caused Pt catalyst poisoned and deactivated. By generation the product isomerate octane number increased from 85 to 90.5. It would be glad to share those experiences to refinery and petrochemical companies and to avoid those bitter experiences.

並列關鍵字

Isomerization ； Poison ； Regeneration