商業化媒裂工場增產輕循環油之方法與成果

Methods and Results for Increasing Production of Light Cycle Oil in a RFCC unit

邱虹梓(Hung-Tzu Chiu) ； 黃楠益(Nan-Yih Huang) ； 蔡長成(Chang-Cheng Tsai) ； Hsiang-Yao Sun ； Che-Yuan Chang ； Hsien-Chang Yang ； Jen-Yaw Chang ； Ching-Tiem Tsai ； Chien-Chung Chang ； Wei-Jian Wang ； Jen-Liang Wu ； Home-Ming Shiue ； Feng-Yu Hsu ； Hsin-Feng Hsu ； Chien-Ying Lee ； Jil-Chyn Shin

《石油季刊》 58卷1期 (2022/03) Pp. 55-65

摘要

因應汽油供過於求，商業化媒裂工場進行輕循環油增產工作來增加工場效益。增產輕循環油工作包括調整汽油和輕循環油分餾點、降低反應溫度、調整新鮮觸媒添加量、回煉塔底油以及更改新鮮觸媒配方。媒裂工場使用低Z／M觸媒，有助於達成以下的預期目標：（1）增加輕循環油產率、（2）降低汽油產率、（3）降低塔底油產率以及（4）增加輕循環油API和塔底油API。未來增加觸媒的ZSM-5含量，可以將更多汽油裂解成C3C4s，獲得汽油減量、C3C4s增量以及汽油辛烷值提升等好處，並且擴大低反應溫度操作的彈性，進一步增加輕循環油產率。增產輕循環油工作期間，需要適當地調整轉化率、汽油／輕循環油分餾點以及塔底油回煉量，同時進行塔底油密度和黏度管控，避免塔底油廻路發生結垢問題，另外需考量輕循環油去化，適當地調整輕循環油特性。此次增產輕循環油工作，成功地將轉化率由79.8wt%降至75.6wt%，輕循環油產率由原先的11.8wt%提升至17.0wt%，塔底油產率不增加，反而降低1wt%，低價值的燃料氣和焦碳產率也減少，使得總產值增加。依轉撥價格計算，增產輕循環油後的產值每天增加約40萬元，增產輕循環油操作天數為165天，總效益約6600萬元。此次增產輕循環油的方法和成果可作為媒裂工場調整產率之參考，視未來巿場價格變化，協助媒裂工場達到高效益操作之目標。

關鍵字

重油觸媒裂解工場 ； 輕循環油 ； Z／M觸媒 ； 擇形分子篩

並列摘要

In response to the oversupply of gasoline, the increased production of Light Cycle Oil (LCO) was performed in a commercial RFCC unit to improve profits. The production of LCO increased in the RFCC unit by adjusting gasoline and LCO cut point, reducing ROT, optimizing fresh catalyst addition rate, recycling CFB, and changing the fresh catalyst formula. The RFCC unit used low Z/M catalysts to achieve the following promising targets: (1) increase LCO yield, (2) reduce gasoline yield, (3) reduce CFB yield, and (4) increase LCO API. The ZSM-5 content of the catalyst increased to further decrease gasoline yield, and compensate for the fact that the low ROT operation causes the reduction in C3C4s production and gasoline RON. It is important to monitor properties of CFB for preventing the fouling problems. According to HDS operation and LCO product specification, the adjustment of LCO properties needed to be done by changing gasoline and LCO cut point. The conversion of the RFCC unit successfully reduced from 79.8wt% to 75.6wt%, and the LCO yield increased from 11.8wt% to 17.0wt%. Due to decrease in CFB yield, fuel gas yield and coke yield, total liquid product yield increased, resulting in an increase in unit profit by about 400,000 yuan per day. The accumulated profit for 165 days of the operation is about 66 million yuan. Methods for adjusting RFCC yield are provided in this study, as the basis for the future increase of the profitability of the refinery according to market prices.

並列關鍵字

RFCC unit ； LCO ； Z/M Catalyst ； ZSM-5 additive

參考文獻

“MD FCC Catalysts, Boosting middle distillates production in fluidized catalytic cracking”, Albemarle, Technical report. 2018

“New Resid Fluid Catalytic Cracking (FCC) Catalyst Technology for Maximum Distillates Yield, Demonstrated in Big West Oil’s Salt Lake City Refinery”, BASF, Technical note. 2015

“Recycle and Catalytic Strategies for Maximum FCC Light Cycle Oil Operations”, GRACE Davison, Technical report. 2011