Claims:WE CLAIM:
1. A dual functional catalyst additive for increase in propylene yield and decrease in total olefin content, said dual functional catalyst additive represented by a formula
(CuO)A(TiO)B(FeO)C(M1O)D(P2O5)E(SiO2)K(Al2O3)(100-X-K)
wherein, M1O is at least one metal oxide of at least one metal selected from the groups IIIA, VIB, and lanthanides,
wherein, A+B+C+D+E = X,
A is copper oxide content in the range of 0.5 to 5 wt%,
B is titanium oxide content in the range of 0 to 2 wt%,
C is ferrous oxide content in the range of 0 to 1 wt%, and B+C =1 wt%,
D is M1O content in the range of 0 to 3 wt%,
E is P2O5 content in the range of 3 to 15 wt%, and
K is SiO2 (silica) content in the range of 20 to 75 wt%.
2. The catalyst additive as claimed in claim 1, said catalyst additive is represented by a formula
(CuO)A(TiO)B(FeO)C(M1O)D(P2O5)E(SiO2)K(Al2O3)(100-X-K)
wherein, M1O is at least one metal oxide of at least one metal selected from the groups IIIA, VIB, and lanthanides,
wherein, A+B+C+D+E = X,
A is copper oxide content in the range of 0.5 to 5 wt%,
B is titanium oxide content in the range of 0 to 1 wt%,
C is ferrous oxide content in the range of 0 to 1 wt%, and B+C =1 wt%,
D is M1O content in the range of 0 to 2 wt%,
E is P2O5 content in the range of 8 to 12 wt%, and
K is SiO2 (silica) content in the range of 58 to 65 wt%.
3. The catalyst additive as claimed in claim 1, said catalyst additive is
(CuO)0.5(TiO)1(FeO)0.5(P2O5)10(SiO2)65(Al2O3)23.
4. The catalyst additive as claimed in claim 1, said catalyst additive is
(CuO)3(TiO)1(LaO)1(CeO)1(P2O5)12(SiO2)60(Al2O3)20.
5. The catalyst additive as claimed in claim 1, said catalyst additive is
(CuO)4(FeO)1(MoO)1(GaO)2(P2O5)6(SiO2)58(Al2O3)28.
, Description:FIELD
The present disclosure relates to the field of FCC catalyst additives.
DEFINITIONS
As used in the present disclosure, the following words and phrases are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used to indicate otherwise.
Equilibrium catalyst (E-CAT): Equilibrium catalyst is a partially deactivated Fluidized Catalytic Cracking Catalyst which has spent an equilibration time in the FCC reactor and represents a catalyst having particles of average age and activity. The equilibrium catalyst (E-CAT) composition depends on the fresh catalyst, catalyst make up and additive composition and typically contains silica, alumina, phosphorous pentoxide, rare earth oxide and metals originating from the feed such as Nickel, Vanadium, Iron, Sodium, and Calcium and the like.
Dual functional: The characteristic of the material, which is helpful in simultaneously achieving two different results.
Wet impregnation: Wet impregnation is a commonly used technique for the synthesis of heterogeneous catalysts. In this method, the active metal precursor is dissolved in an aqueous or organic solution. The metal-containing solution is then added to a catalyst support to obtain slurry. The slurry can be dried and calcined to drive off the volatile components, thereby resulting in the deposition of the metal on the catalyst support surface.
Pour point: Pour point of a liquid is the temperature at which it becomes semi solid and loses its flow characteristics.
Conradson carbon residue (CCR): CCR is a laboratory test used to provide an indication of the coke-forming tendencies of oil. Quantitatively, the test measures the amount of carbonaceous residue remaining after the oil's evaporation and pyrolysis.
Kinematic Viscosity: Kinematic viscosity is a quantity representing the dynamic viscosity of a fluid per unit density and is measured in the centistokes (cSt).
Attrition Resistance: An attrition resistance is a measure of the resistance of a granular material to wear and is measured in wt%.
BACKGROUND
Demand for light hydrocarbons is increasing exponentially. Therefore, the use of the fluid catalytic cracking (FCC) units is important for converting heavy hydrocarbons to light hydrocarbons. In the FCC unit, the heavy hydrocarbons are subjected to cracking in the presence of an FCC catalyst such as E-CAT to obtain cracked hydrocarbons comprising light hydrocarbons. Cracking of heavy hydrocarbons in the presence of E-CAT produces propylene in low yields, typically, less than 6 wt%, and high amounts of olefins, typically 45 wt% to 55 wt%.
The higher content of olefins in the cracked naphtha and in the cracked naphtha derived products is responsible for fouling of the downstream processing units, automobile engines, petroleum product storages and transportation containers. The higher content of olefins in the gasoline derived from naphtha does not meet the environmental regulations. If the content of total olefins in the cracked naphtha and in the products derived from the cracked naphtha is brought down, the fouling in the process units can be controlled and cracked naphtha can be absorbed in the gasoline stream leading to increased refinery margins.
Conventionally, the FCC catalyst additives are specifically used either for increasing the propylene yield or for reducing the total olefin content. However, for practical purposes both results are necessary and therefore, the FCC catalyst additives need to be optimized for combination of both results.
There is, therefore, felt a need for the development of additives to simultaneously increase the propylene yield and reduce the content of total olefins in the cracked naphtha.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a dual functional FCC catalyst additive.
Another object of the present disclosure is to provide a dual functional FCC catalyst additive, which when used in combination with an FCC catalyst, is capable of providing the cracked naphtha with reduced total olefin content and enhanced propylene yield.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure provides a dual functional FCC catalyst additive for optimizing increase in propylene yield and decrease in total olefin content. The dual functional catalyst additive of the present disclosure can be represented by a formula
(CuO)A(TiO)B(FeO)C(M1O)D(P2O5)E(SiO2)K(Al2O3)(100-X-K)
wherein, M1O is metal oxide of a metal selected from the groups IIIA, VIB, and lanthanides, and D is a metal oxide content in the range of 0 to 3 wt% of the total amount of the dual functional FCC catalyst additive, preferably 0 to 2 wt%,
A is copper oxide content in the range of 0.5 to 5 wt% of the total amount of the dual functional FCC catalyst additive,
B is titanium oxide content in the range of 0 to 2 wt% of the total amount of the dual functional FCC catalyst additive, preferably 0 to 1 wt%,
C is ferrous oxide content in the range of 0 to 1 wt% of the total amount of the dual functional FCC catalyst additive, and B+C = 1.
E is P2O5 content in the range of 3 to 15 wt% of the total amount of the dual functional FCC catalyst additive, preferably 8 to 12 wt%,
X is total metal oxide content (A+B+C+D+E) and
K is SiO2 (silica) content in the range of 20 to 75 wt% of the total amount of the dual functional FCC catalyst additive, preferably 58 to 65 wt%.
In accordance with one embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)0.5(TiO)1(FeO)0.5(P2O5)10(SiO2)65(Al2O3)23.
In accordance with another embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)3(TiO)1(LaO)1(CeO)1(P2O5)12(SiO2)60(Al2O3)20.
In accordance with still another embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)4(FeO)1(MoO)1(GaO)2(P2O5)6(SiO2)58(Al2O3)28.
DETAILED DESCRIPTION
Conventionally, crude oil is upgraded into lighter fractions by using the FCC process. Propylene and LPG are among the fractions obtained by cracking of crude oil. There is a continuous increase in the demand of propylene and LPG due to their wide range of applications. The higher olefin content of the cracked naphtha fraction creates fouling problems in automobile engines, storage and transportation vessel and does not meet the environmental gasoline regulations (BSIV, V and VI). Therefore, there is a need for an FCC catalyst/additive, which will enhance refinery margins by increasing the yields of propylene and producing cracked naphtha with reduced total olefin content.
The present disclosure envisages a dual functional FCC catalyst additive, which when used in combination with an FCC catalyst for cracking heavy hydrocarbon feed, is capable of providing enhanced propylene yield and cracked naphtha with reduced olefins content.
The present disclosure provides a dual functional FCC catalyst additive represented by the formula
(CuO)A(TiO)B(FeO)C(M1O)D(P2O5)E(SiO2)K(Al2O3)(100-X-K).
M1O is at least one metal oxide of at least one metal selected from the groups IIIA, VIB, and lanthanides, and D is metal oxide (M1O) content in the range of 0 to 3 wt% of the total amount of the catalyst additive, preferably 0 to 2 wt%.
The copper oxide content, represented by A, is in the range of 0.5 to 5 wt% of the total amount of the dual functional FCC catalyst additive.
The titanium oxide content, represented by B, is in the range of 0 to 2 wt% of the total amount of the dual functional FCC catalyst additive, preferably 0 to 1 wt%.
The ferrous oxide content, represented by C, is in the range of 0 to 1 wt% of the total amount of the dual functional FCC catalyst additive, and B+C = 1.
The phosphorous pentoxide (P2O5) content, represented by E, is in the range of 3 to 15 wt% of the total amount of the dual functional FCC catalyst additive, preferably 8 to 12 wt%.
The silica (SiO2) content, represented by K, is in the range of 20 to 75 wt% of the total amount of the dual functional FCC catalyst additive, preferably 58 to 65 wt%.
In accordance with the embodiments of the present disclosure, X is the total metal oxide content (A+B+C+D+E), which is in the range of 3 wt% to 25 wt% of the total amount of the dual functional FCC catalyst additive.
In accordance with the embodiments of the present disclosure, the dual functional FCC catalyst additive essentially comprises copper oxide, phosphorous pentoxide, silica, alumina, and at least one of titanium oxide and ferrous oxide.
The FCC catalyst additive comprising copper oxide and phosphorous pentoxide impregnated on support material comprising silica and alumina, when used in combination with the FCC catalyst for cracking of heavy hydrocarbons, results in cracked hydrocarbons showing enhanced propylene yield. However the total olefin content of the cracked hydrocarbons is still high and there is slight reduction in the total olefin content.
The FCC catalyst additive comprising copper oxide, phosphorous pentoxide and at least one of titanium oxide and ferrous oxide impregnated on support material, when used in combination with FCC catalyst for cracking of heavy hydrocarbons, results in cracked hydrocarbons showing enhanced propylene yield, as well as reduction in total olefin content.
Thus, it is observed that , the FCC catalyst additive comprising support impregnated with copper oxide, phosphorous pentoxide and at least one of titanium oxide and ferrous oxide along with at least one other metal oxide is also capable of performing the dual function of improving the propylene yield as well as reduction in total olefin content simultaneously.
The dual functional FCC catalyst additive of the present disclosure is optimized by inclusion of at least one metal oxide of at least one metal selected from the group consisting of group IIIA, VIB, and lanthanides, to provide the cracked hydrocarbon with enhanced propylene yield and reduced olefin content in the fluid catalytic cracking of the heavy hydrocarbons.
In accordance with the embodiments of the present disclosure, the dual functional catalyst additive in combination with FCC catalyst is able to increase the propylene yield in the range of 35% to 55%, as well as decrease the liquid olefin content in the range of 20% to 35%.
In accordance with one embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)0.5(TiO)1(FeO)0.5(P2O5)10(SiO2)65(Al2O3)23.
In accordance with another embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)3(TiO)1(LaO)1(CeO)1(P2O5)12(SiO2)60(Al2O3)20.
In accordance with still another embodiment of the present disclosure, the dual functional FCC catalyst additive is
(CuO)4(FeO)1(MoO)1(GaO)2(P2O5)6(SiO2)58(Al2O3)28.
The dual functional FCC catalyst additive of the present disclosure can be prepared using any one method selected from the group consisting of wet impregnation, dry impregnation, pore volume impregnation, spray impregnation, combustion impregnation, solid-solid deposition and the like.
Typically, silica can be obtained from at least one silica source selected from the group consisting of tetraethylorthosilicate, precipitated silica, fumed silica, colloidal silica, sodium silicate and silicon alkoxides.
Typically, silica can be obtained by basic hydrolysis or acidic hydrolysis of the silica source to obtain a gel, which on drying and calcining results in formation of silica.
Typically, alumina can be obtained from at least one alumina source selected from the group consisting of aluminum alkoxide, aluminum hydroxide, aluminum nitrate, aluminum sulfate, aluminum chloride, aluminum carbonate, aluminum bicarbonate, aluminum acetate, aluminum acetylacetonate, aluminum acetonitrile, pseudobohemite, bayerite and gibbsite.
Typically, the alumina can be obtained by basic hydrolysis or acidic hydrolysis of the alumina source.
The dual functional FCC catalyst additive of the present disclosure is prepared by impregnating metal oxides on the support comprising silica and alumina. The sources for the metal oxides are respective metal salts. Typically, the metal salts can be at least one selected from the group consisting of nitrate, sulfate, nitrile, alkoxide, chloride, acetylacetonate, acetate and organometallic compounds.
Typically, the metal salts are independently dissolved in at least one fluid medium to obtain the respective metal salt solutions. The metal salt solutions are mixed with predetermined amounts of silica and alumina to obtain a mixture. The so obtained mixture is dried and calcined to obtain the dual functional FCC catalyst additive.
Typically, the fluid medium can be at least one selected from the group consisting of water, methanol, ethanol, propanol, isopropyl alcohol, butanol and combinations thereof.
In accordance with the embodiments of the present disclosure, the mixture can be dried at a temperature in the range of 150 °C to 250 °C.
In accordance with one embodiment of the present disclosure, the mixture is dried using a spray drier and the spray dried material has an average particle size in the range of 60 to 100 µm.
In accordance with the embodiments of the present disclosure, the surface area of the dual functional FCC catalyst additive is in the range of 120 to 200 m2/g. In one embodiment of the present disclosure, the surface area of the dual functional FCC catalyst additive is 158 m2/g.
In accordance with the embodiments of the present disclosure, the attrition resistance of the dual functional FCC catalyst additive is in the range of 0 to 3 wt%. In accordance with the present disclosure, the attrition resistance is measured using ASTM D5757.
In accordance with the embodiments of the present disclosure, the step of calcination can be carried out at a temperature in the range of 450 °C to 850 °C for a time period in the range of 3 hours to 9 hours.
The dual functional FCC catalyst additive of the present disclosure is used in combination with the FCC catalyst, for cracking a hydrocarbon feed to produce cracked hydrocarbons with enhanced propylene yield and reduced total olefin content.
The hydrocarbon feed can be at least one of C5-C12 hydrocarbons, C4-C6 paraffin, gas oil, vacuum gas oil, oil residue, slurry oil, heavy crude.
The present disclosure is further described in the light of the following laboratory experiments, which are set forth for illustration purpose only, and not to be construed as limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale, and the results obtained can be extrapolated to industrial scale. The experiments used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those of skilled in the art to practice the embodiments herein.
EXPERIMENT
Experiment Set 1: Preparation of dual functional FCC catalyst additives
The dual functional FCC catalyst additives were prepared using the wet impregnation method. Reference additive was prepared for the comparison purpose. The composition of dual functional FCC catalyst additives are summarized in Table 1.
Table 1: Composition of dual functional FCC catalyst additives
Catalyst composition Reference additive Additive 1 Additive 2 Additive 3
SiO2 wt% 65 65 60 58
Al2O3 wt% 23 23 20 28
P2O5 wt% 10 10 12 6
CuO wt% 2 0.5 3 4
FeO wt% - 0.5 - 1
TiO wt% - 1 1 -
LaO wt% - - 3 -
CeO wt% - - 1 -
MoO wt% - - - 1
GaO wt% - - - 2

Experiment Set 2: Performance assessment of the FCC catalyst additive
The dual functional FCC catalyst additives obtained in Experiment Set 1; Additive-1, Additive-2 and, Additive-3 were used in combination with the FCC catalyst (E-CAT) for cracking crude VGO to obtain cracked VGO.
VGO used in cracking process of the present disclosure comprises 57.1 % of saturated hydrocarbons, 33.3% of aromatics, 9.4 % of resin and 0.2 % of asphaltenes. The properties of VGO used, are summarized in Table 2.
Table 2: Composition and properties of VGO
Properties VGO
Density at 15°C (g/cc) 0.915
Sulphur content (wt%) 2.0
CCR (wt%) 0.60
Pour point, °C 45
Kinematic viscosity @100 °C, cSt 7.742

ASTM-7169 Distillation, wt% (°C)
IBP 283
5 345
10 365
30 404
50 429
70 457
90 506
95 529

The composition of cracked VGO was analyzed and the results are summarized in Table 3.
Table 3: Results for cracking of VGO
ECAT
Reference additive Additive 1 Additive 2 Additive 3
Conversion 70 70 70 70 70
Ethylene 0.73 1.83 2.76 2.14 1.91
Propylene 7.54 9.87 11.52 10.47 10.35
LPG 21.49 27.51 29.94 28.33 28.17
Gasoline 41.65 36.63 32.04 35.24 35.77
Total olefins 29.14 16.45 23.06 18.98 19.26
Reduction in olefins (%) 0 43.55 20.86 34.87 33.91
Increase in propylene (%) 0 31.01 52.90 38.91 37.32

The FCC processes performed using E-cat and reference additive were considered as the comparative examples.
From Table 3, it is evident that the dual functional FCC catalyst additive of the present disclosure when used in combination with the FCC catalyst (E-cat) produce cracked VGO comprising light hydrocarbons with increased propylene yield and reduced olefins content, as compared to E-CAT or E-CAT in combination with reference additive. The cracking process, where only E-CAT is used, shows lower propylene content and higher total olefin content as compared to the cracking process where E-CAT is used in combination with additives of the present disclosure.
Similarly, cracking process where reference additive comprises CuO and P2O5 shows increased propylene yield, however, the total olefin content is not reduced. When the dual functional FCC catalyst additive comprising either TiO (Additive-2), or FeO (Additive-3) or combination thereof (Additive-1) show optimized results with increase in the propylene yield and reduced total olefin content.
Thus, from results it can be established that the dual functional catalyst additives of the present disclosure perform dual function of increasing the propylene yield and reduced olefin content.
TECHNICAL ADVANCEMENTS AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a dual functional FCC catalyst additive that:
- enable production of propylene with high yield; and
- reduces the total olefin content of the cracked products.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.