DESC:FIELD
The present disclosure relates to a catalyst composition, a method for preparing the same and its use for upgrading hydrocarbon containing olefinic impurities.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.
Pugging: The term “pugging” refers to working a material into a soft, plastic condition suitable for making different objects, without air pockets.
Upgrading hydrocarbon: The term “upgrading hydrocarbon” refers to reducing olefinic impurities from a hydrocarbon containing olefinic impurities.
BACKGROUND
In refining and petrochemical industry, aromatic hydrocarbons are commonly found to contain olefinic impurities. These olefinic impurities are formed as by-products during the petrochemical processes such as transalkylation, and reforming or steam cracking of naphtha. During the downstream processing of these aromatic hydrocarbons, the highly reactive olefinic contaminants form undesirable by-products, lead to poisoning of catalysts, and/or cause fouling. Therefore, it is essential to eliminate these olefinic impurities from the aromatic hydrocarbon. For example, production of para-xylene by the adsorption process requires the C8 aromatic feed stream to be free from olefinic impurities, so as to safeguard the expensive adsorbent. Hence, these olefinic impurities are removed from up-streams of the adsorption unit using specialty clay. However, clay has a short life and cannot be regenerated, thus necessitating frequent changeover, resulting in generation of huge volumes of solid waste.
Therefore, development of a new composition as a catalyst for reducing olefinic impurities from a hydrocarbon containing olefinic impurities in the area of refining and petrochemicals is of commercial interest.
Therefore, there is felt a need to provide a catalyst composition that mitigates the drawbacks mentioned herein above.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a catalyst composition.
Still another object of the present disclosure is to provide a process for preparing the catalyst composition.
Yet another object of the present disclosure is to provide a catalyst composition for upgrading hydrocarbon containing olefinic impurities.
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
In a first aspect, the present disclosure relates to a catalyst composition comprising at least one first component and at least one second component. The first component is selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, Y is selected from group IIIA elements and a is in the range of 0.001 to 5.0 moles, b is in the range of 0.001 to 100 moles, c is in the range of 0.0001 to 0.2 moles and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500. The second component is selected from oxides of the elements of group IIIA, oxides of elements of group VA, complex oxides of a combination of aluminium and phosphorous, aluminium phosphate, and combinations thereof. The proportion of the first component to the second component is in the range of 60:40 to 80:20.
The zeolite is selected from the group consisting of UZM-8, ZSM-5 and ZSM-11. Typically, the zeolite is UZM-8.
In one embodiment, the second component is aluminium phosphate having a molar ratio of phosphorous to aluminium in the range of 0.5 to 3.
The catalyst composition is in a shape selected from spherical, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, and honeycomb structure.
In a second aspect, the present disclosure provides a process for preparing the catalyst composition. The process involves providing at least one first component selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, Y is selected from group IIIA elements and a is in the range of 0.0001 to 5.0 moles, b is in the range of 0.01 to 100 moles, c is in the range of 0.0001 to 0.2 moles, and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500. In the next step at least one second component selected from oxides of the elements of group IIIA, oxides of elements of group VA, complex oxides of a combination of aluminium and phosphorous, and aluminium phosphate, is provided. The first component and the second component are mixed to obtain a mixture, which is then pugged with water to obtain a pugged mixture. The pugged mixture is extruded to obtain extrudates, followed by drying the extrudates to obtain dried extrudates and then calcining the dried extrudates to obtain the catalyst composition.
In one embodiment, the first component and the second component are ground to obtain a powdered mixture and then acetic acid is added to the powdered mixture to provide the mixture comprising the first component and the second component. The second component is selected from alumina, and gallium oxide.
In another embodiment, in the step of providing second component, alumina is added to water under stirring to obtain a slurry, followed by slowly adding phosphoric acid (H3PO4) to the slurry, and then diluting the resultant mixture with water to obtain aluminium phosphate hydrogel. Then, in the step of mixing, the aluminium phosphate hydrogel is added to ground and powdered first component to provide the mixture comprising the first component and the second component.
The step of pugging is carried out for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
The extrudates have diameter in the range of 0.2 mm to 5 mm and length in the range of 0.2 mm to 20 mm.
The step of drying is carried out at a temperature in the range of 15 °C to 35 °C for a time period in the range of 40 minutes to 80 minutes, followed by drying at a temperature in the range of 100 °C to 140 °C for a time period in the range of 300 minutes to 400 minutes.
The step of calcining is carried out at a temperature in the range of 500 °C to 700 °C for a time period in the range of 300 to 400 minutes.
In a third aspect, there is provided a process for upgrading a hydrocarbon containing olefinic impurities using the catalyst composition of the present disclosure. The process comprises introducing hydrocarbon containing olefinic impurities into a reactor, followed by contacting the hydrocarbon containing olefinic impurities with the catalyst composition of the present disclosure, at a temperature in the range of 100 °C to 500 °C, preferably at a temperature in the range of 150 °C to 200 °C, for a time period in the range of 30 minutes to 300 minutes, preferably for a time period in the range of 150 minutes to 200 minutes to produce an upgraded hydrocarbon.
DETAILED DESCRIPTION
Production of para-xylene by the adsorption process requires that the C8 aromatic hydrocarbon feed be free from olefinic impurities, so as to safeguard the expensive adsorbent. Hence, these olefinic impurities are removed from up-streams of the adsorption unit using specialty clay. However, clay has a short life and cannot be regenerated, thus necessitating frequent changeover, resulting in generation of huge volumes of solid waste. Conventionally, MWW type zeolite, for example MCM-22, MCM-36, MCM-49, MCM-56 are employed for removal of olefinic impurities from the hydrocarbon containing olefinic impurities.
The present disclosure envisages a catalyst composition comprising an environmentally friendly material that can replace the existing catalyst. The catalyst composition of the present disclosure has enhanced efficacy and process reliability, longer catalytic life, and can be regenerated with ease and reused. The present invention provides a catalyst composition comprising a non-MWW type zeolite for reducing olefinic impurities from the hydrocarbon containing olefinic impurities.
In a first aspect of the present disclosure, there is provided a catalyst composition. The catalyst composition comprises at least one first component and at least one second component in pre-determined proportion.
The first component is selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, and Y is selected from group IIIA elements. Further, ‘a’ is in the range of 0.01 to 5.0, ‘b’ is in the range of 1 to 100, ‘c’ is in the range of 0.1 to 0.2 and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500.
The second component is selected from oxides of the elements of group IIIA and oxides of the elements of group VA, complex oxides of a combination of aluminium and phosphorous, aluminium phosphate, and combinations thereof.
The present disclosure uses a non-MWW based zeolite as the first component of the catalyst composition. It is observed that the performance of the catalyst compositions based on non-MWW have enhanced efficiency for the removal of olefinic impurities from a hydrocarbon. Surprisingly, it is observed that the use of UZM-8 (non-MWW zeolite) as a first component improved performance of the shaped catalyst composition by at least 20% as compared to the use of MCM-22 (MWW zeolite) as the first component.
Clays can be employed as the second component for preparing shaped zeolite based catalyst compositions. However, clays have certain inherent properties, such as the high acid strength of surface hydroxyl group, which adversely affect the performance of zeolite based catalyst compositions.
The second component used in the process of the present disclosure does not adversely affect the performance of zeolite based catalyst compositions. In some cases, it is observed that the performance of zeolite based catalyst compositions in relation to removal of olefins has been enhanced due to use of the second component of the present disclosure. Surprisingly, it is observed that the efficiency of the shaped catalyst composition comprising alumina or aluminum phosphate as a second component showed improved catalytic activity.
The proportion of the first component to the second component is in the range of 60:40 to 80:20.
The zeolite is selected from the group consisting of UZM-8, ZSM-5 and ZSM-11. In one embodiment, the zeolite is UZM-8.
The second component is selected from the group consisting of aluminium oxide, and gallium oxide.
In one embodiment, the second component is alumina.
In another embodiment, the second component is an aluminium phosphate hydrogel having a molar ratio of phosphorous to aluminium in the range of 0.5 : 1 to 1 : 3.
The catalyst composition is in a shape selected from spherical, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, and honeycomb structure. The diameter of the catalyst composition is in the range of 0.2 mm to 5 mm, and the length of the catalyst composition is in the range of 0.2 mm to 20 mm.
In a second aspect of the present disclosure, there is provided a process for preparing the catalyst composition. The process comprises providing at least one first component selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, Y is selected from group IIIA elements and a is in the range of 0.0001 to 5.0, b is in the range of 0.01 to 100, c is in the range of 0.0001 to 0.2 and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500. In the next step, at least one second component selected from oxides of the elements of group IIIA, oxides of elements of group VA, complex oxides of a combination of aluminium and phosphorous, and aluminium phosphate, is provided. The first component and the second component are mixed to obtain a mixture. In the next step, the mixture is pugged with water to obtain a pugged mixture. The pugged mixture is extruded to obtain extrudates, which are dried to obtain dried extrudates and then the dried extrudates are calcined to obtain the catalyst composition.
In one embodiment, wherein alumina is used as the second component, alumina and the first component are ground thoroughly to obtain a powdered mixture to which acetic acid is added to obtain the mixture comprising the first component and the second component.
In another embodiment, wherein aluminium phosphate is used as the second component, in the step of providing second component, alumina is added to water under stirring to obtain a slurry, and then phosphoric acid (H3PO4) is slowly added to the slurry, followed by diluting the resultant mixture with water to obtain aluminium phosphate hydrogel. Then, in the step of mixing, the aluminium phosphate hydrogel is added to the ground and powdered first component to obtain the mixture comprising the first component and the second component.
Typically, the mixture comprising the first component and the second component is pugged for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
The pugged mixture is extruded to obtain extrudates having a diameter in the range of 0.2 mm to 5 mm and length in the range of 0.2 mm to 20 mm.
Typically, the extrudates are dried at a temperature in the range of 15 °C to 35 °C for a time period in the range of 40 minutes to 80 minutes, followed by drying at a temperature in the range of 100 °C to 140 °C for a time period in the range of 300 minutes to 400 minutes.
Typically, the dried extrudates are calcined at a temperature in the range of 500 °C to 700 °C for a time period in the range of 300 minutes to 400 minutes.
The present invention comprises a process for upgrading hydrocarbon containing olefinic impurities by employing a catalyst composition comprising UZM-8 zeolite, which belongs to a non-MWW zeolite category.
In a third aspect of the present disclosure, there is provided a process for upgrading a hydrocarbon containing olefinic impurities by using the catalyst composition of the present disclosure. The process comprises introducing hydrocarbon containing olefinic impurities into a reactor, followed by contacting the hydrocarbon containing olefinic impurities with the catalyst composition of the present disclosure at a temperature in the range of 100 °C to 500 °C, preferably at a temperature in the range of 150 °C to 200 °C, for a time period in the range of 30 minutes to 300 minutes, preferably for a time period in the range of 150 minutes to 200 minutes, to produce an upgraded hydrocarbon.
In one embodiment, the catalyst composition comprises 70% zeolite.
For reducing the olefinic impurities in the hydrocarbon by 50 wt% or more, it is required that the ratio of the amount of the catalyst composition to the amount of the hydrocarbon containing olefinic impurities is in the range of 2:35 to 5:35 by weight.
Typically, benzene and toluene formation, during the upgrading of the hydrocarbon containing olefinic impurities, is less than 200 ppm.
In one embodiment, the catalyst composition of the present disclosure, wherein the first component is UZM-8 (a non-MWW zeolite), is 60% more efficient in removing olefinic impurities from the hydrocarbon in comparison with the conventional catalyst compositions based on MWW zeolites.
The UZM-8 zeolite is a new type of layered material which is different from the MWW topology. The better catalytic performance of the catalyst composition of the present disclosure could possibly be due to very highly disordered nature of the UZM-8 layered material, thus providing much lower diffusional resistance to the reactant molecules when dealing with larger molecules such as molecules of C8+ aromatic hydrocarbons and also possibly C8+ olefins.
The catalyst composition of the present disclosure has superior catalytic performance in removing olefinic impurities from a hydrocarbon containing olefinic impurities, in comparison with the catalyst compositions with known zeolites in the prior art.
In one embodiment, the quantity of the UZM-8 based catalyst composition required for removing a given amount of olefinic impurity from the hydrocarbon containing olefinic impurities is far less than the quantity of the conventional MWW based catalyst composition.
The catalyst composition of the present disclosure is considered to be a spent catalyst composition when the efficiency of the catalyst composition to remove olefinic impurities from the hydrocarbon, is reduced to less than 50 % (due to continuous usage), with respect to the efficiency of the fresh catalyst.
The spent catalyst composition of the present disclosure is regenerated by calcining the spent catalyst composition at a temperature in the range of 450 °C to 600 °C, for a time period in the range of 1 hour to 10 hours in an oxidizing atmosphere.
The spent catalyst composition of the present disclosure can be regenerated without any significant loss in the efficiency of the regenerated catalyst composition for removing olefinic impurities from a hydrocarbon containing olefinic impurities.
In one embodiment, the catalyst composition of the present disclosure is subjected 4 successive regeneration cycles without any significant loss in the efficiency for removing olefinic impurities from a hydrocarbon containing olefinic impurities.
Therefore, the catalyst composition of the present disclosure provides benefits of long service life, thereby avoiding the frequent catalyst replacement and generation of huge solid waste. Further, the spent catalyst composition is easily regenerated and efficiently used for removing olefinic impurities from a hydrocarbon.
The present disclosure is further described in light of the following laboratory scale experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. These laboratory scale experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial/commercial scale.
Experimental details
Experiment-1: Preparation of MWW type zeolite (MCM-22) and catalyst composition thereof
A mixture of sodium aluminate (61 g) and water (1400 ml) in a 5000 ml polypropylene (PP) beaker was placed under an overhead mechanical stirrer. The mixture was stirred at 300 rpm for 10 minutes and a clear solution was obtained. Separately, NaOH (17 g) was dissolved in water (1000 ml), which was then added to the solution of sodium aluminate and then stirred for another 30 minutes.
Subsequently, hexamethyleneimine (HMI) (194 g) was added to the above solution, followed by stirring for 30 minutes at room temperature. Finally, precipitated silica (620 g) was added slowly to this resultant mixture, and then further stirred for 1 hour to obtain a gel.
The gel was subjected to hydrothermal treatment at 170 °C for 30 hours in an autoclave with continuous stirring. After the crystallization process, the solid product was separated and washed thoroughly with water, until it is free of alkali. Finally, the material was dried at 120 °C overnight in an oven. The powder XRD pattern of the zeolite indicated that the synthesized material is MCM-22.
The compositions (on molar basis) and conditions used for preparation of MWW zeolite are summarized in Table-1.
The as-synthesized zeolite material contained the occluded templating agent, and thus for the formulation purpose, the actual material content were determined after subjecting the zeolite material to loss on ignition (LOI) test. Similarly, the second component was also examined for extent of loss on ignition. To achieve the desired final composition of the catalyst composition, initial quantities of the corresponding zeolite and the second component, were corrected for LOI, and the final composition of the catalyst composition was reported on LOI basis.
Preparation of shaped catalyst composition comprising MCM-22 zeolite and alumina
Condia alumina (having LOI 27 wt%) (61.6 g) and MCM-22 zeolite (130.4 g) from the stock prepared above were ground thoroughly using a mortar-pastel to obtain a powdered mixture. Acetic acid (227.8 g, 3.7 % aqueous solution) was added to the powdered mixture and the resultant mixture was pugged thoroughly. The pugged mixture was extruded using a 1.5 mm die. The extrudates were dried at room temperature for 1 hour, followed by drying at 120 °C for 6 hours in an air oven. The dried sample was calcined at 540 °C for 6 hours under flowing air. Zeolite content in the final catalyst composition (on loss free basis) was 70 % by weight. The extrudates were subjected to ammonium ion exchange, followed by washing and calcination at 540 °C under air flow for 6 hours to obtain the active proton form of the catalyst.
Experiment-2: Preparation of UZM-8 zeolite of the present disclosure and catalyst composition thereof
Aluminium-tri-sec-butoxide (97 %) (1.45 g) was added to dimethyl diethyl ammonium hydroxide (DEDMAOH, 20% aqueous solution) (34 g) under vigorous stirring. In the next step tetraethyl ortho silicate (TEOS, 98 %) (36.49 g) and deionized water (23 g) were added slowly and the mixture was homogenized with a mechanical stirrer and aged overnight to allow complete hydrolysis. The solution was then concentrated with a rotary evaporator to remove alcohols obtained during hydrolysis and also some amount of water to obtain aluminosilicate gel.
In the next step, DEDMAOH (34 g, 20 % aqueous solution) was added to the aluminosilicate gel solution (60 g) obtained in the above step, followed by the addition of NaCl solution (0.7 g NaCl dissolved in 3 g of water), and the resultant mixture was stirred for 2 hours to obtain a homogeneous solution with composition of: 0.1716 SiO2: 0.0028 Al2O3:0.0060 Na2O: 4.4627 H2O: 0.1141 DEDMAOH.
This solution was transferred into Teflon lined autoclave and subjected to hydrothermal crystallization at 150 °C for 7 days under stirring at 100 rpm. The solid product was collected by centrifugation, washed with deionized water and dried overnight in an oven at 100 °C. The powder XRD pattern of the zeolite indicated that the synthesized material is UZM-8. The UZM-8 zeolite is represented by the formula aM2O : bXO2 : cY2O3; and a = 0.0060 moles, b = 0.175 moles, and c = 0.0028 moles.
The composition is expressed in molar ratio as SiO2/Al2O3 = 60, Na/SiO2 = 0.07, H2O/SiO2 = 26, R/SiO2 = 0.66, Na2O/SiO2 = 0.035.
Table-1: Compositions and conditions for synthesis of MWW and UZM-8 zeolites
Experiment 1 2
Silica Source Precipitated Silica TEOS
Molar composition
SiO2/Al2O3 30 60
H2O/SiO2 15 26
Na/SiO2 0.15 0.07
HMI/SiO2 0.2 --
DEDMAOH/SiO2 -- 0.66
Crystallization Conditions
Temperature (°C) 170 150
Stirring speed (rpm) 250 100
Time (hours) 30 168
Characteristic Properties
Crystalline Phase MCM-22 UZM-8

Preparation of shaped catalyst composition comprising UZM-8 zeolite and alumina
Condia alumina (LOI 27 wt%) (2.1 g) and UZM-8 zeolite (LOI 19 wt%) (4.32 g) obtained above were ground thoroughly using a mortar-pastel to obtain a powdered mixture. Acetic acid (5.06 g, 3.7 % aqueous solution) was added to the powdered mixture and the resultant mixture was pugged thoroughly. The pugged mixture was extruded using a 1.5 mm die. Extrudates were dried at room temperature for 1 hour, followed by drying at 120 oC for 6 hours in an air oven. Dried sample was calcined at 600 oC for 6 hours under flowing air. Zeolite content in the final catalyst composition (on loss free basis) was 70 % by weight. The extrudates were subjected to ammonium ion exchange, followed by washing and calcination at 540 °C under air flow for 6 hours to obtain an active proton form of the catalyst.
Experiments 3-4: Performance of catalyst compositions prepared in experiments 1 and 2
The catalytic performance of the catalyst composition prepared in experiments 1 and 2 were evaluated for reduction of olefin content from a hydrocarbon containing olefinic impurities. Composition of the Deheptanizer bottom hydrocarbons, employed in the olefin removal experiments is summarized in Table-2.
Table-2: Composition of Deheptanizer Column Bottom

Component wt%
Non-aromatics 1.3
Toluene 1.56
Ethyl benzene 8.31
Xylenes 44.51
C9 Aromatics 36.23
C10 + Heavy Aromatics 8.09

Extrudates (5 g) obtained in experiments 1 and 2 were added to commercial Deheptanizer column bottom hydrocarbon (35 g) in a stainless steel bomb of 100 ml capacity. The reactor was purged with nitrogen to remove air and was then closed. The bomb reactor was heated at a pre-determined temperature for a pre-determined time duration mentioned in Table-3 and then the reactor was cooled to ambient temperatures. The hydrocarbon liquid was separated from the solid catalyst, and was examined for level of olefinic impurity.
Olefin concentration of the feed and product samples was determined as Bromine Index (BI) of the sample following standard test method ASTM D-1491. The results are summarized in Table-3.

Table 3: Performance of MWW zeolite based catalyst composition and UZM-8 zeolite based catalyst composition towards removal of olefinic impurities from hydrocarbon containing olefinic impurities.
Experiment No Catalyst Source Reaction Conditions Results % reduction of BI
(Olefin Conv.)
Temp.
(°C) Time
(h) Hydrocarbon (Feed) BI Upgraded hydrocarbon (Product) BI
Experiment 3 Experiment 1 180 3 618 374 39
Experiment 4 Experiment 2 180 3 618 235 62

It is clearly seen from Table-3, that the UZM-8 based catalyst composition is far more efficient than the MCM-22 based catalyst composition for removing olefinic impurities from the hydrocarbon containing olefinic impurities. The UZM-8 based catalyst composition is 37 % more efficient than the MCM-22 based composition.
Experiment-5: Preparation of shaped catalyst composition comprising MCM-22 zeolite and aluminium phosphate hydrogel
Condia alumina (16.9 g) was added to demineralized (DM) water (49.1 g) in a Teflon beaker and the mixture was stirred for 10 minutes to obtain a slurry. H3PO4 (28.4 g) was added drop wise to the above slurry and it was transformed into a thick and smooth hydrogel. DM water (49.3 g) was added into the gel and stirred for another 10 minutes. This gel was added to ground and powdered MWW zeolite (87.6 g) (from the stock as prepared in experiment-1) and pugged thoroughly with DM water (18 g). It was pugged for 10 minutes and extruded using 1.5 mm die. Extrudates were dried at room temperature for 1 hour, followed by drying at 120 °C for 6 hours. Dried sample was calcined at 540 °C for 6 hours under flowing air. Zeolite content in the final catalyst composition was 70% by weight. The extrudates were subjected to ammonium ion exchange, followed by washing, and calcination at 540 °C under air flow for 6 hours to obtain an active proton form.
Experiment-6: Preparation of shaped catalyst composition comprising UZM-8 zeolite and aluminium phosphate in accordance with the present disclosure
Condia alumina (LOI 27 wt%) (0.94 g) was added to DM water (2.0 g) in a teflon beaker and the mixture stirred for 10 minutes to obtain a slurry. H3PO4 (1.56 g) was added drop wise to the above slurry and it was transformed into a thick and smooth gel. DM water (2.18 g) was added into the gel and stirred for another 10 minutes. This gel was added to ground and powdered UZM-8 zeolite (4.74 g) obtained in experiment-2 (LOI 19 wt%) and pugged thoroughly with DM water (2.20 g). It was pugged for 10 minutes and extruded using 1.5 mm die. Extrudates were dried at room temperature for 1 hour, followed by drying in an oven at 120 oC for 6 hours. Dried sample was calcined at 600 oC for 6 hours under flowing air. Zeolite content in the final catalyst composition was 70 % by weight. The extrudates were subjected to ammonium ion exchange, followed by washing and calcination at 540 °C under air flow for 6 hours to obtain an active proton form.
Experiments 7-8: Performance of catalyst compositions prepared in experiments 5 and 6
Extrudates (5 g) were added to commercial Deheptanizer column bottom hydrocarbon (35 g) (having a composition as summarized in Table-2), in a stainless steel bomb of 100 ml capacity. Extrudates prepared in experiments 5 and 6 were employed for the purpose. The reactor was purged with nitrogen to remove air and was closed. The bomb reactor was heated at predetermined temperature and duration mentioned in Table-4. After this, the reactor was cooled to ambient conditions. The hydrocarbon liquid was separated from the solid catalyst, and was examined for level of olefinic impurity. Olefin concentration of the feed and product samples was determined as Bromine Index (BI) of the sample following standard test method ASTM D-1491. The results are summarized in Table-4.
Table 4: Performance of MWW zeolite based catalyst composition and UZM-8 zeolite based catalyst composition towards removal of olefinic impurities from the hydrocarbon containing olefinic impurities

Experiment No Catalyst Source Reaction Conditions Results % reduction of BI
(Olefin Conv.)
Temp. (°C) Time (h) Hydrocarbon (Feed) BI Upgraded hydrocarbon
BI
Experiment 7 Experiment 5 180 3 614 343 44
Experiment 8 Experiment 6 180 3 614 171 72

It is clearly seen from Table-4 that the UZM-8 based catalyst composition of the present disclosure is more efficient than MCM-22 based composition in removing olefins impurities from the hydrocarbon containing olefinic impurities. The UZM-8 based catalyst composition is more than 60 % more efficient than the MCM-22 based composition.
Experiments 9-13: Performance of catalyst composition prepared in experiment-2
The performance of UZM-8 based catalyst composition prepared using alumina as the second component as described in experiment-2 was studied. Performance evaluation tests were carried out using 1 g, 2 g, 3 g, 4 g, and 5 g of extrudates prepared in experiment-2, and following the procedure as described in experiments 3-4, and the results obtained are summarized in Table-5.
Table-5: Performance of UZM-8 based catalyst composition towards removal of olefinic impurities from the hydrocarbon containing olefinic impurities.
Experiment No Catalyst Quantity, g Reaction Conditions Results % reduction of BI
(Olefin Conv.)
Temp. (°C) Time (h) Hydrocarbon (Feed) BI Upgraded hydrocarbon
BI
Experiment 9 1 180 3 618 485 21
Experiment 10 2 180 3 620 388 37
Experiment 11 3 180 3 620 302 51
Experiment 12 4 180 3 618 261 58
Experiment 13 5 180 3 620 234 62
Experiments 14-16: Performance of catalyst composition prepared in experiment-6
The performance of UZM-8 based catalyst composition prepared using aluminophosphate hydrogel as second component as described in experiment-6 was studied. The performance evaluation tests were carried out using 1 g, 2 g, and 3 g of extrudates, and following the procedure as described in experiments 3-4 and the results obtained are summarized in Table-6.

Table-6: Performance of UZM-8 based catalyst compositions towards removal of olefinic impurities from the hydrocarbon containing olefinic impurities
Experiment No Catalyst Quantity, g Reaction Conditions Results % reduction of BI
(Olefin Conv.)
Temp. (°C) Time (h) Hydrocarbon (Feed) BI Upgraded hydrocarbon
BI
Experiment 14 1 180 3 627 392 37
Experiment 15 2 180 3 626 285 55
Experiment 16 3 180 3 626 225 64
It is seen from Table-5 and Table-6 that the catalyst composition of the present disclosure, comprising UZM-8 and alumina or aluminium phosphate, is more efficient than the MCM-22 based catalyst composition. It is clear from the above studies, that to remove a given quantity of olefinic impurities from the hydrocarbon containing olefinic impurities, the quantity of UZM-8 based catalyst composition required is much less than that the quantity of MCM-22 based catalyst composition. Hence, smaller sized reactors can be used with lesser capital investment, further, the utility requirement is reduced and the entire operation becomes simple.
Experiments 17-21: Regeneration of the spent catalyst of the present disclosure.
The experiments 17-21 provide the studies for the regeneration of the spent catalyst composition of the present disclosure. The catalyst composition of the present disclosure is considered to be a spent catalyst composition when the efficiency of the catalyst composition to remove olefinic impurities from the hydrocarbon, is reduced to less than 50 % (due to continuous usage), with respect to the efficiency of the fresh catalyst.

Experiment-17:
A fresh batch of catalyst composition (35 g) was prepared according to the procedure given in experiment-2. The performance of the catalyst composition was evaluated following the procedure previously described in experiments 7-8. The results obtained are included in Table-7.
Experiment-18: First regeneration of the spent catalyst
Fresh catalyst (as prepared in example 17) (30 g), was subjected to accelerated aging conditions in a continuous flow reactor. After 10 days of continuous operation, the efficiency of the catalyst composition for removing olefinic impurities decreased to 45 % with respect to that of the fresh catalyst at the beginning of run, indicating that the zeolite catalyst composition was deactivated and was in spent form.
The spent catalyst composition was separated, and was dried in an oven at 120 °C for two hours. The dried spent catalyst composition was then calcined in air at 540 °C for 6 hours. The calcined zeolite composition was cooled to ambient temperature to obtain regenerated zeolite catalyst composition.
The extrudates were clean white after the regeneration process. The regenerated zeolite catalyst composition, thus obtained, was the first regenerated zeolite catalyst composition.
The first regenerated zeolite catalyst composition (5 g) was employed for the removal of olefinic impurities from a fresh feed of commercial Deheptanizer bottom following the procedure as previously described in experiments 7 and 8. The reaction conditions and the results obtained are presented in Table-7.
Experiment-19: Second regeneration of the spent catalyst
The first regenerated catalyst composition (28.5 g) was subjected to accelerated aging conditions. After 11 days of continuous operation, the efficiency of the catalyst composition to remove olefinic impurities decreased to 41% with respect to the efficiency of the first regenerated catalyst composition to remove olefinic impurities at the beginning of the run, indicating that the first regenerated zeolite catalyst composition was in the spent form.
The spent first regenerated zeolite catalyst composition was separated, and was regenerated using the process mentioned in experiment-18. This sample was the second regenerated zeolite catalyst composition.
The second regenerated zeolite catalyst composition (5 g) was employed for the removal of the olefinic impurities from a fresh feed of commercial Deheptanizer bottom following the procedure as previously described in experiments 7 and 8. The reaction conditions and the results obtained are presented in Table-7.
Experiment-20: Third regeneration of the spent catalyst
The second regenerated zeolite catalyst composition (22 g) was subjected to accelerated aging conditions. After 9 days of continuous operation, the efficiency of the catalyst composition to remove olefinic impurities decreased to 45% of the efficiency of the second regenerated zeolite catalyst composition to remove olefinic impurities at the beginning of the run, indicating that the second regenerated zeolite catalyst composition was in the spent form.
The spent second regenerated zeolite catalyst composition was separated, and was regenerated using the process mentioned in experiment-18. This sample was the third regenerated zeolite catalyst composition.
The third regenerated zeolite catalyst composition (5 g) was employed for the reduction of the olefins from a fresh feed of commercial Deheptanizer bottom following the procedure as previously described in experiments 7 and 8. The reaction conditions and the results obtained are presented in Table-7.
Experiment-21: Fourth regeneration of the spent catalyst
The third regenerated zeolite catalyst composition (16 g) was subjected to accelerated aging conditions. After 10 days of continuous operation, the efficiency of the catalyst composition to remove olefinic impurities decreased to 41% of the efficiency of the third regenerated zeolite catalyst composition to remove olefinic impurities at the beginning of the run, indicating that the first regenerated zeolite catalyst composition was in spent form.
The spent third regenerated zeolite catalyst composition was separated and, was regenerated using the process mentioned in experiment-18. This sample was the fourth regenerated zeolite catalyst composition.
The fourth regenerated zeolite catalyst composition (5 g) was employed for the removal of the olefinic impurities from a fresh feed of commercial Deheptanizer bottom following the procedure as previously described in experiments 7 and 8. The reaction conditions and the results obtained are presented in Table-7.
Table-7: Regenerability of the spent catalyst composition of the present disclosure
Experiment No Number of regenerations Reaction Conditions Results % reduction of BI
(Olefin Conv.)
Temp. (°C) Time (h) Hydrocarbon (Feed) BI Upgraded hydrocarbon
BI
Experiment 19 Fresh 180 3 614 225 63
Experiment 20 1 180 3 607 228 62
Experiment 21 2 180 3 610 226 63
Experiment 22 3 180 3 619 235 62
Experiment 23 4 180 3 609 238 61

It is clearly seen from Table-7 that the catalyst composition of the present disclosure can be regenerated by calcinating the spent catalyst composition under oxidizing conditions, and the regenerated catalyst composition of the present disclosure removed 61-63 % of the olefinic impurities from the hydrocarbon.
Experiment-22: Formation of benzene and toluene during removal of olefinic impurities using the catalyst composition of the present disclosure
The extent of benzene and toluene formation during the removal of olefinic impurities from commercial C8 aromatics, while employing the UZM-8 based catalyst composition of the present disclosure was studied. The catalyst extrudates of experiment-2 were used for the study.
Extrudates (5 g) were added to commercial Deheptanizer column bottom hydrocarbon (35 g) in a stainless steel bomb of 100 ml capacity. The reactor was purged with nitrogen to remove air and was closed. The bomb reactor was heated at 180 °C for 3 hours. After this, the reactor was cooled to ambient conditions. The hydrocarbon liquid was separated from the solid catalyst, and was examined for level of olefinic impurity, and the result obtained is presented in Table-8.
Table 8: GC Analysis of Hydrocarbon (Feed) and Upgraded hydrocarbon
Hydrocarbon (Feed) Upgraded hydrocarbon
Lighters 1.19 1.11
Benzene 0 0
Toluene 1.56 1.58
C8 Aromatics 52.82 52.68
C9 Aromatics 36.23 36.01
C10 Aromatics and heavies 8.2 8.62
It is seen from the analysis of the Hydrocarbon (Feed) and Upgraded hydrocarbon by gas chromatograph presented in Table-8 that the benzene formation was nil, while toluene formation was 200 ppm.
The catalyst composition of the present disclosure is effectively used for reducing olefinic impurities from a hydrocarbon containing olefinic impurities. The catalyst composition exhibits a higher catalytic performance than that of the conventional catalyst and hence small quantity of the catalyst composition is required for upgrading of the hydrocarbon containing olefinic impurities. The better performance of the catalyst composition could possibly be due to the highly disordered nature of the UZM-8 layered material, thus providing much lower diffusional resistance to the reactant molecules. The second component also plays a significant role in the catalytic performance of the catalyst composition of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
- a catalyst composition based on UZM-8 zeolite for removal of olefinic impurities from hydrocarbon containing olefinic impurities;
- a catalyst composition having higher stability and longer life and hence reducing the frequency of changeovers for loading the catalyst; and
- a catalyst composition that can be regenerated, thus avoids solid waste generation.
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.
,CLAIMS:WE CLAIM
1. A catalyst composition comprising:
- at least one first component selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, Y is selected from group IIIA elements and a is in the range of 0.0001 to 5.0, b is in the range of 0.01 to 100, c is in the range of 0.0001 to 0.2 and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500; and
- at least one second component selected from oxides of the elements of group IIIA, oxides of elements of group VA, complex oxides of a combination of aluminium and phosphorous, and aluminium phosphate,
wherein the proportion of said first component to said second component is in the range of 60:40 to 80:20.
2. The catalyst composition as claimed in claim 1, wherein said zeolite is selected from the group consisting of UZM-8, ZSM-5 and ZSM-11.
3. The catalyst composition as claimed in claim 1, wherein said zeolite is UZM-8.
4. The catalyst composition as claimed in claim 1, wherein said second component is aluminium phosphate having a molar ratio of phosphorous to aluminium in the range of 0.5 : 1 to 1 : 3.
5. The catalyst composition as claimed in claim 1, wherein said catalyst composition is in a shape selected from spherical, cylindrical, tri-lobed, tetra-lobed, star, ring, tablets, pellets, and honeycomb structure.
6. A process for preparing a catalyst composition, said process comprising:
i. providing at least one first component selected from zeolites having the formula aM2O : bXO2 : cY2O3, wherein M is selected from alkali or alkaline earth elements, X is selected from group IVA elements, Y is selected from group IIIA elements and a is in the range of 0.01 to 5.0, b is in the range of 1 to 100, c is in the range of 0.1 to 0.2 and a/b is in the range of 0.01 to 0.1 and b/c is in the range of 10 to 500;
ii. providing at least one second component selected from oxides of the elements of group IIIA, oxides of elements of group VA, complex oxides of a combination of aluminium and phosphorous, and aluminium phosphate;
iii. mixing said first component and said second component to obtain a mixture;
iv. pugging said mixture with water to obtain a pugged mixture;
v. extruding said pugged mixture to obtain extrudates;
vi. drying said extrudates to obtain dried extrudates; and
vii. calcining said dried extrudates to obtain said catalyst composition.
7. The process as claimed in claim 6, wherein in the step (iii) said first component and said second component are ground to obtain a powdered mixture and acetic acid is added to the powdered mixture to provide the mixture comprising said first component and said second component,
wherein said second component is selected from alumina, and gallium oxide.
8. The process as claimed in claim 6, wherein:
- step (ii) comprises adding alumina to water under stirring to obtain a slurry, followed by slowly adding phosphoric acid (H3PO4) to the slurry, and then diluting the resultant mixture with water to obtain aluminium phosphate hydrogel;
- step (iii) comprises adding said aluminium phosphate hydrogel to ground and powdered first component to provide the mixture comprising said first component and said second component.
9. The process as claimed in claim 6, wherein step (ii) is carried out for a time period in the range of 1 minute to 60 minutes, preferably 5 minutes to 15 minutes.
10. The process as claimed in claim 6, wherein said extrudates have diameters in the range of 0.2 mm to 5 mm and length in the range of 0.2 mm to 20 mm.
11. The process as claimed in claim 6, wherein step (iv) is carried out at a temperature in the range of 15 °C to 35 °C for a time period in the range of 40 minutes to 80 minutes, followed by drying at a temperature in the range of 100 °C to 140 °C for a time period in the range of 300 minutes to 400 minutes.
12. The process as claimed in claim 6, wherein the step of calcining is carried out at a temperature in the range of 500 °C to 700 °C for a time period in the range of 300 minutes to 400 minutes.
13. A process for upgrading a hydrocarbon containing olefinic impurities, said process comprising:
I. introducing hydrocarbon containing olefinic impurities into a reactor;
II. contacting said hydrocarbon containing olefinic impurities with said catalyst composition as claimed in claim 1, at a temperature in the range of 100 °C to 500 °C, preferably at a temperature in the range of 150 °C to 200 °C, for a time period in the range of 30 minutes to 300 minutes, preferably for a time period in the range of 150 minutes to 200 minutes to produce an upgraded hydrocarbon.