DOS Series Catalyst FCC catalyst
DOS catalyst is a kind of gasoline sulfur.reducing catalyst ZDOS catalyst is a kind of bottom cracking catalyst. Either of them is suitable for resid cracking, and gasoline yield boosting.
DOS catalysts have good bottom cracking capability and excellent resistance to metal contamination. They can enhance gasoline yield, and reduce gasoline olein and sulfur content.
By investigation on the sulfur reduction mechanism, an efficient “Lewis acid-base pairs” compound was found. It is of stable structure, can reduce the sulfur content of FCC gasoline without affecting the hydrogen transfer activity and cracking activity of the catalyst while processing a FCC feedstock with high heavy metals content. Meanwhile, new generation modified Y zeolite (DOSY) was developed. DOSY zeolite shows super hydrothermal stability. DOSY zeolite can enhance active site accessibility and trap vanadium particularly.
The main specifications of DOS catalyst are shown in Table 1.
Table 1 Main Specifications of DOS Catalyst
|Main specifications||Typical data|
|Chemical components, %|
|LOI, m%||≤ 13.0||12.0|
|Attrition Index, %/h||≤ 1.3||2.1|
|Bulk Density, g/ml||0.65-0.80||0.72|
|Surface Area, m2/g||≥ 230||264|
|Pore Volume, ml/g||≥ 0.35||0.38|
|0-40μm, m%||≤ 20||17.5|
|800oC/4h, m%||≥ 75.0||79|
DOS catalyst commercial application test was carried out at SINOPEC Cangzhou Petrochemical in 2005. The main test results are listed in Table 2~Table 4. The results show that DOS catalyst could reduce slurry and coke yield, meanwhile, increase the total yields of LPG and gasoline and diesel. DOS catalyst could also reduce gasoline sulfur content and olefin content.
Table 2 Feedstock Properties
|Density (20℃), kg/m3||931.7||931.4|
|Viscosity (80℃), mm2/s||9.025||13.80|
|ASTM distillation, ℃|
|Recovered at 500℃, %||74|
Table 3 Products Distribution
|LPG + Gasoline + Diesel, %||82.07||82.64|
Table 4 Gasoline Properties
|Density (20℃), kg/m3||734.0||727.3|
|ASTM distillation, ℃|
|Sulfur in Gasoline, m%||0.084||0.0579|
|Vapor Pressure, KPa||74||72|
|Inductive Period, min||300||750|
|Aromatics Content, v/v%||20.6||21.8|
|Olefin Content, v/v%||33.7||33.9|
Picture 1 Relations between Sulfur Transfer Index and DOS Catalyst Inventory
DOS catalyst has been applied in SINOPEC refineries such as Cangzhou Petrochemical, Fujian Petrochemical and Maoming Petrochemical, also in refineries in USA, Thailand and Singapore.
DOS, ZDOS, ZDOS-M, ZDOS-T2, CDOS-SR1 and CDOS-B/CDOS-B5.