Mineral oils: processes and products – Chemical conversion of hydrocarbons – Cracking
Reexamination Certificate
2003-06-11
2004-04-20
Griffin, Walter D. (Department: 1764)
Mineral oils: processes and products
Chemical conversion of hydrocarbons
Cracking
C208S121000, C208S122000, C208S123000, C208S120100, C208S120200, C208S120300, C502S355000, C502S349000, C502S353000, C502S305000, C502S344000, C502S317000, C502S172000, C502S200000, C502S208000
Reexamination Certificate
active
06723228
ABSTRACT:
This invention relates to an additive used in catalytic cracking of hydrocarbons and a process of catalytic cracking of hydrocarbons using the same, especially to an additive used in catalytic cracking of heavy oils and a process of catalytic cracking of heavy oils using the same in petroleum processing industry.
The feedstocks of heavy oil catalytic cracking has the feature of high detrimental metal contents of Ni, V, Na and Fe, etc. In the process of catalytic cracking reaction and catalyst regeneration, almost all of Ni and V are deposited on the catalyst, poisoning the cracking catalyst. Nickel promotes the dehydrogenation reaction and deteriorates the selectivity of the catalyst and increases the coke yield and hydrogen content in dry gas; also, vanadium can migrate into the molecular sieve, damaging the molecular sieve lattice structure and reducing the catalyst activity. As the results, the light oil yield is reduced and economic benefit is affected. Thereby, to overcome the detrimental effect of heavy metal Ni and V on the catalyst in processing heavy oil, to enhance and improve the catalyst activity and selectivity, ensure the long-term smooth operation of heavy oil catalytic cracking unit and meet the requirements of contaminant emissions such as CO, etc stipulated by the increasingly stringent environmental regulations, some additives of special function or functions, such as metal passivator and CO oxidation promoter, etc are used in the catalyst cracking of hydrocarbons. The metal passivator maintains good catalyst activity and selectivity of the catalytic cracking mainly by passivating Ni, V, etc on the catalyst. The CO oxidation promoter promotes the oxidation of CO to CO
2
, permitting the full combustion of CO in the dense-phase zone of the regenerator. This prevents the damage of equipment by “post-burning” of CO in the dilute-phase zone and minimizes the environmental pollution of CO when it is discharged with the flue gas emission. Furthermore, the full combustion of CO makes it possible to fully recover the otherwise lost energy from CO.
The existing metal passivator are classified into two categories in terms of function, i.e. the single-function metal passivator which is nickel passivator or vanadium passivator composed of single effective metal like Sb, Sn or Bi; and difunction metal passivator composed of composite metals like Sb—Sn, Sb—Bi, Sb—Re, etc which can simultaneously passivate nickel and vanadium. There are two ways for the addition of metal passivators: one is to add it to the reactor with the catalytic cracking feedstock and this method is usually applied for the liquid metal passivator. The other is to add it to the reactor with the catalyst and this method is usually applied for solid metal passivator such as vanadium trapping agent.
In the art, a number of patents relating to metal passivators and CO oxidation promoters, such as U.S. Pat. Nos. 4,562,167 and 5,565,399 are disclosed. One liquid metal passivator is disclosed in U.S. Pat. No. 4,562,167 in which the liquid metal passivator is a liquid solution or suspension containing Sb or at least one of Sb compounds and Sn or at least one of Sn compounds, wherein the weight ratio of antimony to tin is 0.5:1 to 10:1. It can passivate the detrimental metals such as Ni, V and Fe etc deposited on the catalytic cracking catalyst, but it possesses no function to reduce CO emission in regenerator flue gas. In U.S. Pat. No. 5,565,399, a CO oxidation promoter which promotes the oxidation of CO is disclosed. Said promoter comprises Pt, alumina, lanthanum oxide and cerium oxide, wherein platinum is supported on the spherical alumina which contains at least 2 wt. % of lanthanum oxide and 3~8 wt. % of cerium oxide and the supported Pt is 50~1000 ppm. This promoter is effective in reducing CO emission in regenerator flue gas but has no function to passivate the detrimental metals Ni and V on the catalytic cracking catalyst. The particulate CO promoter is added into the reactor together with the catalyst.
It can be found from the existing patents of metal passivator and CO oxidation promoter that efforts have been made to develop a catalytic cracking assistant with multiple functions but little success is achieved. The metal passivators or CO oxidation promoters have single function which is demonstrated by the fact that the passivator can only passivate the detrimental metals and can not reduce CO emission and that the CO oxidation promoter can only reduce the CO emission and can not passivate the contaminating metals. But in the commercial practice, these two functions are simultaneously needed by the process unit. Therefore, both metal passivator and CO oxidation promoter have to be added to the unit. In addition, most commercial metal passivators are liquid, which are added to the reactor by mixing them with the feed oil; whereas most oxidation promoters are solid, which are introduced to the reactor with the catalyst by catalyst loading system. This means that, for a process unit, different additives need to be added by different addition systems to meet the different function requirements. This complicates the operation and increases the operating and management cost. If the liquid CO oxidation promoter is intended to be used, the noble metals, such platinum, palladium, which is usually included therein must be transformed into their stable compounds, such as platinum chloride, which will corrode the devices.
One object of the present invention is to provide a liquid multi-function additive used in the catalytic cracking of hydrocarbons, in order to solve the problem of single-function of existing technologies, that is, the additive can only passivate the detrimental nickel and vanadium deposited on the catalyst or can only reduce the CO emission from flue gas. The present additive is effective in both passivating the detrimental nickel and vanadium deposited on the catalytic cracking catalyst and reducing CO emission from flue gas, and is easily operated with production cost decreased.
The further object of the present invention is to provide a process of catalytic cracking of hydrocarbons using the present additive.
The term “catalytic cracking” used in the present invention includes gas oil fluid catalytic cracking (FCC), residuum catalytic cracking (RCC), deep catalytic cracking (DCC) and other catalytic conversion processes based upon the continuous catalytic cracking reaction-regeneration mechanisms for processing hydrocarbons, such as MGG, ARGG and MIO, and the like family processes.
The term “metal” used in the present invention includes metal and metalloid.
The present additive is characterized in that: said additive is in the form of homogeneous liquid and comprises a composite metal compound, wherein said composite metal compound consists of the oxides, hydroxides, organic acid salts, inorganic acid salts or metal organic complex compounds of at least one of the 1st group metals and at least one of the 2nd group metals, said 1st group metals include the metals of the IIIA, IVA, VA, VIA group of the Element Period Table, boron, silicon, phosphor and tellurium, preferably antimony, bismuth and combinations thereof: said 2nd group metals include alkali-earth metals, transition metals and rare earth metals, preferably Cd, Zn, Mg, Ca, Sr, Ba, Cr, Mo, Mn, Co, Cu, Sc, Ti, La, Ce, Pr, Nd, Sm, Eu and combinations thereof.
The present liquid additive is either oil soluble or water soluble depending upon its composition, it can be prepared as solutions colloid emulsions suspension and other homogeneous liquid dispersion. The oil-soluble additive can be dispersed well in the feed oil, while the water soluble additive is inexpensive and easy to clean and operate.
The contents and ratios of said metal components, dispersion medium and optional assistant components are not critical, so long as the homogeneous liquid can be formed. The ratio of the 1st group metal component to the 2nd group metal component is also not critical, and it depends on the amount of nickel and vanadium in the catalytic crackin
Deng Xianliang
Guo Haiqing
Liu Jinlong
Liu Shufang
Qi Wenyi
Arnold Jr. James
China Petro-chemical Corporation
Griffin Walter D.
Ladas & Parry
LandOfFree
Additive used in catalytic cracking of hydrocarbons and a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Additive used in catalytic cracking of hydrocarbons and a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Additive used in catalytic cracking of hydrocarbons and a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3208959