1 .xylene isomerization
Paraxylene is an important raw material of polyester fiber.
In the isomerization of xylene, large grain zsm-5 has better selectivity for p-xylene, but its catalytic activity is lower than that of small grain with the same structure.Xylene isomerization was carried out on nihzsm-5, which was caused by NH3 pair
The selective poisoning of acid center in dealkylation and disproportionation reaction can inhibit the loss of C8 aromatics and increase p-xylene
The production rate.Isomerization can also be performed on ni-zsm-5 and Pt containing zsm-5 catalysts.ZSN - 5 (boiling
S-si-al ratio ≥10) -pt -- Sn was used for xylene isomerization at a reaction temperature of 250 -- 550℃.
Sn in the catalyst inhibits hydrogenation of benzene rings.
2. synthesis of gasoline from methanol
Methanol can be converted into gasoline by using zsm-5 as catalyst
Oil products do not contain hydrocarbons above C10, hydrocarbon products in gasoline distillate accounts for about 88%, conversion rate up to 10
0%.Zsm-5 zeolite containing B2O3 can be used as catalyst for methanol conversion to gasoline.Literature report,
Zsm-5 zeolite (SiO2 / Al2O3 = 27 ~ 84) is used to convert methanol into gasoline, showing autocatalytic reaction
Chemical properties.By raising the reaction temperature from 80℃ to 300℃, the hydrocarbon production was increased rapidly.
3. selective reorganization
Using zsm-5 as catalyst and adopting a process similar to selective reforming, it can increase the aromatics and the octane of reformed gasoline
Octane value.The concentration of aromatics in the liquid product is up to 90%, and chemical grade aromatics can be obtained without solvent extraction.With the carrying
The ability of zsm-5 with different metals to produce aromatics was compared.Zinc in ZSM - 5
Its aromatization was improved obviously.
4 .alkylation of benzene and ethylene to ethylbenzene
Using HZSM - 5 or Ρ a catalyst HZSM - 5, can make the alkylation of benzene with ethylene gas phase reaction to produce b
Benzene.The selectivity of ethylbenzene and the aging of catalyst could be improved by adding phosphorous compounds to hzsm-5
Speed.
5. preparation of paraxylene by alkylation of toluene and methanol
The unmodified zsm-5 catalyst is generally given near equilibrium in the reaction of toluene and methanol
Xylene mixture.The paraxylene from large grain zsm-5 accounted for 46% of the total xylene.
In alkylation reaction, the selectivity of p-xylene generally increases with the increase of temperature.
6. hydrogenation of diesel oil to condensate
Most of the crude oil in China belongs to paraffin-base or intermediate base crude oil, which has a high wax content, resulting in a high freezing point of the distillate.
According to the situation of diesel production and demand in China in 2005, diesel supply still cannot meet the requirements.Diesel hydrogenation decondensing technology is not
However, it can meet the needs of low solidification point diesel in cold regions and is an effective means to increase diesel production.
The key technology of diesel oil hydrogenation decondensing process is hydrogenation decondensing catalyst.The initial hydrogenation decondensing catalyst was used
The zsm-5 zeolite synthesized by machine template is prepared from matrix, with the disadvantages of high price, high initial reaction temperature and
There are environmental problems.The zsm-5 zeolite synthesized directly by fushun petrochemical research institute is used as matrix and modified by inorganic acid treatment, dipping active metal nickel and high temperature water vapor treatment
Fdw-1 (industrial grade 3) was the first catalyst with stable dyeing and reaction performance to realize industrialization
Catalyst, has been widely used in domestic refineries, fdw-1 hydrogenation decondensing catalyst in Harbin
The application results of the refinery show that the solidification point of the raw material is reduced from 1℃ to 1℃ through the selective cracking of hydrodewaxing catalyst
At -55℃, the yield of diesel was 92.5%, gasoline 4.0%, and the total yield of liquid was 98.5%.
Sinopec fushun research and development of a new generation of fdw-3 hydrogenation decondensing catalyst, its
The catalytic performance is better than 3881 catalyst, and it can not only be used for catalytic dewaxing of diesel distillate, but also for production of lubricating oil
Catalytic dewaxing of lubricating oil base oil.
7. catalytic dewaxing of lubricating oil
The catalytic dewaxing process of lubricating oil takes advantage of the shape-selective cracking characteristics of zsm-5 molecular sieve to remove wax molecules from the raw materials
It is converted into C3 ~ C4 gas and naphtha, and then removed from the lubricating oil by distillation to achieve the purpose of reducing pour point.
Zeolite belongs to the high silicon zeolite, its acid center mainly comes from the hydroxyl group combined with aluminum skeleton.Because of the ZSM - 5
Zeolite can be silica - al ratio from 10 to pure silicon (silica - al -1), its solid acid type,
Strength and distribution can be regulated, so it is widely used in the oil refining industry, especially in diesel decondensing and lubricating oil catalysis
Dewaxing and modification of gasoline are widely used.
