Special Catalyst For MCP Process FCC catalyst
Specially formulated catalyst for MCP process.
OMT series catalyst has good bottoms conversion ability, high propylene yield, low dry gas yield and high propylene selectivity as a result of using advanced preparation technology of improving catalyst carrier and ZSP-3 zeolite with excellent crystal structure, high activity and high stability. OMT-1 has macropore structure, large surface area and high equilibrium activity.
First, some design methods come true such as improving carrier activity and selectivity, enhancing selective cracking ability of raw oil, regulating primary reaction temperature ratio, etc. Meanwhile, in order to improve the unsaturated degree of intermediate product and increase the yield of light olefins, hydrogen transfer reaction is controlled properly by means of regulating degree of rare-earth modification and ultra-stability, increasing silicon aluminum ratio of zeolite, introducing high silicon aluminum ratio catalytic materials and inhibiting zeolite activity of hydrogen transfer reaction. Furthermore, the product separating rate is increased with the methods of increasing the macropore ratio in catalyst carrier, improving the outward diffusion of product molecules, reducing the carrier macropore re-adsorption for product molecules. In addition, primary cracking and further cracking reaction of saturated hydrocarbon and side-chain is enhanced to increase the aromatic hydrocarbon proportion in intermediate and final products, the coking reaction is inhibited to reduce the yield loss resulting from further conversion of aromatic hydrocarbon, both of which are realized by increasing zeolite acid sites intensity, decreasing acid density and improving carrier coking selectivity.
The main specifications of OMT-1 catalyst were shown in Table 1.
Table 1 Main Specifications of OMT-1
|Specific surface area||m2/g||≥190|
|Apparent bulk density||g/ml||0.60～0.85|
|MAT (800℃/4h)||% (m/m)||≥65|
|Attrition Index||% (m/m)||≤2.5|
The first industrial application of OMT-1 catalyst is conducted at Yangzhou Petrochemical 250,000 ton per year MCP unit. The unit takes atmospheric resid of Jiangsu oil field as feedstock and overall liquid yield reaches 80.23% including 37.68% LPG, 17.05% propylene, 5.51% isobutylene, 32.16% C5 + gasoline and 10.39% light diesel oil, which means the overall liquid yield and light olefins yield achieves a high level. The MON is 94.6. The industrial application indicates that OMT-1 catalyst leads to high propylene and gasoline yield, properties of oil are improved and dry gas yield is limited.
Table 2 Main Operating Conditions
|Riser #1 outlet temp., ℃||533|
|Reactor #3 outlet temp., ℃||540|
|Resid feed temp., ℃||220|
|Disengager pressure, KPa||125|
|Regenerator pressure, KPa||128|
|Resid feed rate, kg/h||30200|
|Naphtha recycle quantity, kg/h||4500|
|Recycle oil quantity, kg/h||500|
|Slurry recycle quantity, kg/h||500|
|Air flow, Nm3/h||39540|
Table 3 Product Distribution
Table 4 Liquid Hydrocarbon Distribution
|H2S (desulfurized), mg/m3||5|
SINOCHEM Yangzhou Petrochemical, CNOOC Dongfang Petrochemical and refinery in Thailand.