Catalyst composition for converting light naphtha to aromatic compounds and a process thereof

Abstract

Accordingly, the present invention provides a catalyst composition suitable for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said catalyst composition comprising: (a) a medium pore size zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium. Also, the present invention provides a process for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said process comprising the step of contacting a feedstock comprising the light naphtha with a catalyst composition comprising (a) a medium pore size zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium in presence of carrier gas at temperatures ranging from 400 to 600 C.

Claims

1. A catalyst composition suitable for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said catalyst composition comprising: (a) a hydrogen form medium pore size alumino silicate zeolite that has a pore size of 5-6 ; (b) 0.1 to 5.0 wt % of zinc associated with the zeolite as a promotor; (c) 0.1 to 5 wt % of gallium associated with the zeolite as a promotor; and (d) 0.5 to 1.5 wt % of one or more additional promoters associated with the zeolite, wherein the one or more additional promotors are selected from the group consisting of cerium, tin, cesium, potassium, magnesium, and mixtures thereof.

2. The catalyst composition as claimed in claim 1, wherein the hydrogen form medium pore alumino silicate zeolite has silica to alumina ratio (SAR) in the range of 20 to 200.

3. The catalyst composition as claimed in claim 1, wherein the catalyst composition optionally further comprises a binder material and a filler material.

4. The catalyst composition as claimed in claim 3, wherein the binder material is selected from a group comprising of alumina, silica, silica-alumina and phosphate.

5. The catalyst composition as claimed in claim 3, wherein the filler material is selected from a group comprising of kaolin clay, montmorillnite clay, bentonites clay, laolinite clay and halloysite clay, aluminum trihydrate, bayerite, and gamma alumina.

6. The catalyst composition as claimed in claim 1, wherein the catalyst composition is in the form of spheres, rods, pills, pellets, tablets, granules, cylindrical or multilobe extrudates.

7. The catalyst composition as claimed in claim 1, wherein, the catalyst has 0.5 to 4.0 wt % of zinc and 0.5 to 4 wt % of gallium.

8. The catalyst composition as claimed in claim 1, wherein, the catalyst has 1.0 to 3.0 wt % of zinc and 1.0 to 4 wt % of gallium.

9. A process for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said process comprising the step of contacting a feedstock comprising the light naphtha with a catalyst composition comprising: (a) hydrogen form medium pore size alumino silicate zeolite that has a pore size of 5-6 ; (b) 0.1 to 5.0 wt % of zinc associated with the zeolite as a promotor; (c) 0.1 to 5 wt % of gallium associated with the zeolite as a promotor; and (d) 0.5 to 1.5 wt % of one or more additional promoters associated with the zeolite, wherein the one or more additional promotors are selected from the group consisting of cerium, tin, cesium, potassium, magnesium, and mixtures thereof, wherein the contacting of the feedstock with the catalyst is in presence of carrier gas at temperatures ranging from 400 to 600 C.; wherein the carrier gas is supplied in an amount of 2 to 10 moles per mole of hydrocarbon feedstock; wherein the catalyst is maintained in a fixed bed of a down-flow reactor; wherein the carrier gas comprises nitrogen, hydrogen, or mixtures thereof.

10. The process as claimed in claim 9, wherein a weight hourly space velocity (WHSV) in the range of 0.5 to 2 hour.sup.1 is maintained.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) In the drawings accompanying the specification,

(2) FIG. 1 illustrates a graph showing the variation in terms of production of aromatic yield for different ratios of carrier gas to hydrocarbon feedstock, more particularly, curve 100 shows the variation in terms of production of aromatic yield for different ratios of hydrogen to hydrocarbon feedstock, when hydrogen is used as the carrier gas and curve 200 shows the variation in terms of production of aromatic yield for different ratios of nitrogen to hydrocarbon feedstock, when nitrogen is used as the carrier gas.

DETAILED DESCRIPTION OF THE INVENTION

(3) While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof will be described in detail below. It should be understood, however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the scope of the invention as defined by the appended claims.

(4) The embodiments disclosed herein can provide a catalyst composition suitable for reforming and more particularly for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said catalyst composition comprising (a) a medium pore size zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium.

(5) In an embodiment of the present invention, the medium pore size zeolite is hydrogen form medium pore alumnio silicate zeolite.

(6) In another embodiment of the present invention, the hydrogen form medium pore alumino silicate zeolite has silica to alumina ratio (SAR) in the range of 20 to 200.

(7) In yet another embodiment of the present invention, the medium pore size zeolite is hydrogen form medium pore gallium silicate molecular sieve.

(8) In still another embodiment of the present invention, the catalyst composition optionally further comprises one or more optional promoters selected from the group comprising of Cerium, Chromium, Tin, Cesium, potassium, magnesium, molybdenum and mixtures thereof.

(9) In a further embodiment of the present invention, wherein the one or more optional promotes are present in an amount of 0.5 to 1.5 wt %.

(10) In a furthermore embodiment of the present invention, wherein the catalyst composition optionally further comprises a binder material and a filler material.

(11) In another embodiment of the present invention, wherein the binder is selected from a group comprising of alumina, silica, silica-alumina and phosphate.

(12) In yet another embodiment of the present invention, wherein the filler is selected from a group comprising of kaolin clay, montmorillonite clay, bentonites clay, laolinite clay and halloysite clay, aluminum trihydrate, baverite, and gamma alumina.

(13) In a further embodiment of the present invention, wherein the catalyst is in the form of spheres, rods, pills, pellets, tablets, granules, cylindrical or multi lobe extrudates.

(14) In another embodiment of the present invention, the medium pore size alumnio silicate zeolite has a pore size of about 5-6 .

(15) In yet another embodiment of the present invention, the catalyst has 0.5 to 4.0 wt % of zinc and 0.5 to 4.0 wt % of gallium.

(16) In still another embodiment of the present invention, the catalyst has 1.0 to 3.0 wt % of zinc and 1.0 to 4.0 wt % of gallium.

(17) The present invention also provides a process for converting light naphtha comprising one or more of C5 to C8 carbon atoms to aromatic compounds ranging from C6 to C10 carbon atoms, said process comprising the step of contacting a feedstock comprising the light naphtha with a catalyst composition comprising (a) a medium pore size alumino silicate zeolite; (b) 0.1 to 5.0 wt % of zinc; and (c) 0.1 to 5 wt % of gallium in presence of carrier gas at temperatures ranging from 400 to 600 C.

(18) In an embodiment of the present invention, wherein the catalyst is maintained in a fixed bed of a down-flow reactor.

(19) In another embodiment of the present invention, wherein a weight hourly space velocity (WHSV) in the range of 0.5 to 2 hour.sup.1 is maintained.

(20) In yet another embodiment of the present invention, wherein carrier gas comprises nitrogen, hydrogen or mixtures thereof.

(21) In still another embodiment of the present invention, wherein the carrier gas is supplied in an amount of about 1 to about 20 moles per mole of hydrocarbon feed.

(22) In a further embodiment of the present invention, wherein the carrier gas is supplied in an amount of about 2 to about 10 moles per mole of hydrocarbon feed.

(23) As used herein, the term zeolite relates to an aluminosilicate molecular sieve or zeolite which has been obtained by selective removing from the aluminosilicate molecular sieve alumina and replacing the same with gallium. An overview of their characteristics is for example provided by the chapter on Molecular Sieves in Kirk-Othmer Encyclopedia of Chemical Technology, Volume 16, p 811-853; in Atlas of Zeolite Framework Types, 5th edition, (Elsevier, 2001). The term medium pore sized zeolite as used herein is very well-known in the art; see e.g. Holderich et al. (1988) Angew. Chem. Int. Ed. Engl. 27:226-246. Accordingly, a medium pore size zeolite is a zeolite having a pore size of about 5-6 . Suitable medium pore size zeolites are 10-ring zeolites, i.e. the pore is formed by a ring consisting of 10 SiO.sub.4 tetrahedra. Large pore size zeolites have a pore size of about 6-8 and are of the 12-ring structure type. Zeolites of the 8-ring structure type are called small pore size zeolites. In the above cited Altlas of Zeolite Framework Types various zeolites are listed based on ring structure. Most preferably the zeolite is ZSM-5 zeolite, which is a well-known zeolite having MFT structure. ZSM-5 zeolite has an ellipsoidal pore size of 5.55.6 .

(24) Preferably, the silica (SiO.sub.2) to alumina (Al.sub.2O.sub.3) molar ratio of the zeolite is in the range of about 10-200. In the context of the present invention it was found that the performance and stability of the catalyst in the process of the present invention can be improved when the zeolite comprised in said catalyst has silica, to alumina molar ratio of about 20-200. Zeolites having silica to alumina molar ratio of 10-200 and preferably 20-200 are well known in the art and also are commercially available. Means and methods for quantifying the silica to alumina molar ratio of a zeolite are well known in the art and include, but are not limited to AAS (Atomic Absorption Spectrometer) or ICP (Inductively Coupled Plasma Spectrometry) analysis.

(25) Preferably, the hydrocarbon feedstock is a naphtha feedstock including naphthenes and paraffins that boil within the gasoline range. The preferred feedstock are naphthas consisting principally of naphthenes and paraffins, although, in many cases, aromatics will also be present. This preferred class includes straight-run gasolines, natural gasolines, and synthetic gasolines. Alternatively, it is frequently advantageous to charge thermally or catalytically cracked gasolines, partially reformed naphthas, or dehydrogenated naphthas. Mixtures of straight-run and cracked gasoline-range naphthas can also be used.

(26) Sufficient hydrogen is supplied to provide an amount of about 1 to about 20, preferably about 2 to about 10, moles of hydrogen per mole of hydrocarbon feed entering the reforming zone.

Illustrative Embodiments

(27) The following examples are intended to further illustrate the subject catalyst. These illustrations of embodiments of the invention are not meant to limit the claims of this invention to the particular details of these examples. In all of the following examples, the reactions were carried out at 500 C., with weight hourly space velocity of 1 h.sup.1 using either nitrogen or hydrogen (as mentioned in specific examples) as carrier gas, with hydrocarbons ranging from C5 to C8 as feedstock or specific refinery product (light naphtha) as the feedstock. The catalyst loading ranged from 0.5 to 2 gm and specifically 1 g. The reactions were carried out in the fixed bed down-flow reactor with mass flow controllers, HPLC pump for feed injection and the outlet flow monitored by wetgas/rotameter. Products are analyzed through offline GC equipped with FID using TRWAX column of 60 m0.25 um2.5 mm. Gas samples were analysed by the GC with FID detector using Porapak Q packed column.

Example 1

(28) The zeolite H-ZSM-5 with varying SiO2/Al2O3 ratios (SAR) were tested under the reaction conditions of: Temp.: 500 C., WHSV=1 h.sup.1, TOS=2 h. Catalyst: 2 g. H.sub.2/HC=2 and the results are provided in Table 1. More particularly, as per example 1a, zeolite H-ZSM-5 with SAR of 23 was taken; as per example 1b, zeolite H-ZSM-5 with SAR of 30 was taken; as per example 1d, zeolite H-ZSM-5 with SAR of 80 was taken; as per example 1e, zeolite H-ZSM-5 with SAR of 84 was taken; and for example 1f, zeolite H-ZSM-5 had SAR of 187.

(29) TABLE-US-00001 TABLE 1 Product distribution (wt %) Ex. 1a Ex. 1b Ex. 1c Ex. 1d Ex. 1e Ex. 1f Methane 7.27 8.82 5.67 2.59 2.32 0.74 Ethylene 1.15 1.29 1.65 3.93 3.12 1.140 Ethane 14.06 16.54 13.01 10.77 8.70 17.32 Propylene + 56.92 57.30 59.54 50.11 48.39 3.69 Propane C4HC 8.67 7.69 12.04 25.94 28.06 5.67 Hexane 0.06 0.05 0.08 0.24 0.57 69.33 Benzene 2.90 2.32 1.82 0.83 0.50 0.99 Toluene 4.60 2.86 3.04 2.15 3.24 0.42 Ethylbenzene 0.21 0.13 0.15 0.12 0.29 0.00 P-Xylene 0.41 0.27 0.38 0.43 0.81 0.07 m-Xylene 0.91 0.60 0.85 0.96 1.69 0.35 o-Xylene 0.39 0.27 0.38 0.44 0.77 0.14 Ethyltoluenes 0.13 0.09 0.14 0.17 0.40 0.00 trimethyl- 0.14 0.12 0.18 0.26 0.24 0.07 benzene C-10 and 2.17 1.63 1.09 1.07 0.90 0.07 others n-hexane con- 99.94 99.95 99.92 99.76 99.43 30.67 version wt % Total aromatics 11.85 8.30 8.01 6.43 8.84 2.12

Example 2

(30) Protonated Zeolite Y (Ex. 2) was tested at the same conditions as mentioned in example 1 and compared with example 1a as shown in Table 2.

(31) TABLE-US-00002 TABLE 2 Product distribution (wt %) Ex. 1a Ex. 2 Methane 7.27 2.812 Ethylene 1.15 1.868 Ethane 14.06 3.641 Propylene + Propane 56.92 9.193 C4HC 8.67 11.25 Hexane 0.06 68.11 Benzene 2.90 0.21 Toluene 4.60 1.85 Ethylbenzene 0.21 0.07 P-Xylene 0.41 0.21 m-Xylene 0.91 0.57 o-Xylene 0.39 0.21 Ethyltoluenes 0.13 0.00 trimethylbenzene 0.14 0.00 C-10 and others 2.17 0.00 n-hexane conversion wt % 99.94 31.89 Total aromatics 11.85 3.13

Example 3

(32) Different promoters were added to protonated Zeolite Y and texted as per condition listed in example 1 and compared with the results for example 2 as shown in Table 3. More particularly, as per example 3a, H-Zeolite-Y was promoted with 5% Lanthanum; as per example 3b, H-Zeolite-Y was promoted with 5% Lanthanum and 1% Cerium; as per example 3c, H-Zeolite-Y was promoted with Phosphorous using Phosphoric acid as source; and as per example 3d, H-Zeolite-Y was promoted with Phosphorous using Diammonium phosphate as source.

(33) TABLE-US-00003 TABLE 3 Product distribution (wt %) Ex. 2 Ex. 3a Ex. 3b Ex. 3c Ex. 3d Methane 2.812 1.13 2.032 0.413 0.906 Ethylene 1.868 1.09 1.60 1.128 1.573 Ethane 3.641 1.46 2.76 1.092 1.448 Propylene + Propane 9.193 19.48 32.95 16.028 24.006 C4HC 11.25 14.6 21.96 7.01 15.92 Hexane 68.11 58.1 37.13 73.42 54.74 Benzene 0.21 0.19 0.11 0.08 0.33 Toluene 1.85 1.39 0.53 0.74 0.42 Ethylbenzene 0.07 0.09 0.02 0.00 0.00 P-Xylene 0.21 0.19 0.07 0.01 0.04 m-Xylene 0.57 1.36 0.46 0.08 0.15 o-Xylene 0.21 0.39 0.14 0.00 0.08 Ethyltoluenes 0.00 0.15 0.06 0.00 0.00 trimethylbenzene 0.00 0.25 0.12 0.00 0.12 C-10 and others 0.00 0.06 0.04 0.00 0.27 n-hexane conversion 31.89 41.84 62.87 26.58 45.26 wt % Total aromatics 3.13 4.08 1.56 0.91 1.40

Example 4

(34) Gallium incorporated into the framework of ZSM-5 was modified to protonic form. The H-Ga-ZSM-5 with varying Si/Ga ratios were tested under the reaction conditions as listed in example 1. It may be noted that in this present example, Gallium replaces the aluminum present in the framework of ZSM-5 and is not taken as a promoter. More particularly, as per example 4a, H-Ga-ZSM-5 had Si/Ga ratio of 23; and as per example 4b, H-Ga-ZSM-5 had Si/Ga ratio of 50. The results are provided in Table 4.

(35) TABLE-US-00004 TABLE 4 Product distribution (wt %) Ex. 4a Ex. 4b Methane 10.19 1.89 Ethylene 3.93 7.42 Ethane 5.63 6.55 Propylene + Propane 24.02 31.03 C4HC 10.69 23.62 Hexane 0.10 19.84 Benzene 14.98 0.86 Toluene 25.08 7.17 Ethylbenzene 0.66 0.17 P-Xylene 1.12 0.36 m-Xylene 2.27 0.64 o-Xylene 0.70 0.22 Ethyltoluenes 0.21 0.06 trimethylbenzene 0.04 0.03 C-10 and others 0.37 0.14 n-hexane conversion wt % 99.90 80.16 Total aromatics 45.43 9.64

Example 5

(36) Gallium incorporated into the framework of ZSM-5 was modified to protonic form. The H-Ga-ZSM-5 having Si/Ga ratio of 23 (i.e. example 4a) was taken as the base material and different promoters were introduced into the same and tested under the reaction conditions as listed in example 1. More particularly, in example 5a, H-ZSM-5 having SAR of 23 was taken as the base material and 2% of Zn was added as promoter; and in example 5b, H-ZSM-5 having SAR of 23 was taken as the base material and 4% of Ga was added as promoter. The results are provided in Table 5.

(37) TABLE-US-00005 TABLE 5 Product distribution (wt %) Ex. 5a Ex. 5b Methane 2.27 7.56 Ethylene 3.25 3.86 Ethane 7.72 8.86 Propylene + Propane 19.57 23.96 C4HC 16.45 19.47 Hexane 30.06 3.86 Benzene 4.36 7.92 Toluene 7.70 12.83 Ethylbenzene 0.92 1.09 P-Xylene 2.08 2.83 m-Xylene 2.31 3.82 o-Xylene 0.88 1.49 Ethyltoluenes 0.46 0.63 trimethylbenzene 0.18 0.24 C-10 and others 1.80 1.59 n-hexane conversion wt % 69.94 96.14 Total aromatics 20.68 32.44

Example 6

(38) The zeolite H-ZSM-5 with varying SiO2/Al2O3 ratios (SAR) were taken as base material and 8% Phosphorous was added and tested under the reaction conditions as listed in example 1. More particularly, in example 6a, H-ZSM-5 having SAR of 23 was taken as the base material and 8% Phosphorous was added as promoter; in example 6b, H-LSM-5 having SAR of 50 was taken as the base material and 8% Phosphorous was added as promoter; and example 6c, H-ZSM-5 having SAR of 80 was taken as the base material and 8% Phosphorous was added as promoter. The results are provided in Table 6.

(39) TABLE-US-00006 TABLE 6 Product distribution (wt %) Ex. 6a Ex. 6b Ex. 6c Methane 2.81 1.30 1.74 Ethylene 1.81 6.41 11.17 Ethane 8.81 7.29 9.78 Propylene + Propane 56.20 48.56 47.76 C4HC 19.01 34.45 27.63 Hexane 0.01 1.11 1.75 Benzene 1.56 0.29 0.08 Toluene 4.80 0.59 0.09 Ethylbenzene 0.30 0.00 0.00 P-Xylene 0.82 0.00 0.00 m-Xylene 1.81 0.00 0.00 o-Xylene 0.80 0.00 0.00 Ethyltoluenes 0.27 0.00 0.00 trimethylbenzene 0.19 0.00 0.00 C-10 and others 0.81 0.00 0.00 n-hexane conversion wt % 99.99 98.89 98.25 Total aromatics 11.36 0.88 0.17

Example 7

(40) The zeolite H-ZSM-5 having SAR of 23 was taken as the base material and different promoters at a constant rate of 2% was added and tested under the reaction conditions as listed in example 1. More particularly, in example 7a, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Cerium was added as promoter; in example 7b, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Potassium was added as promoter; and in example 7c, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Cesium was added as promoter. The results are provided in Table 7.

(41) TABLE-US-00007 TABLE 7 Product distribution (wt %) Ex. 7a Ex. 7b Ex. 7c Methane 7.49 1.94 0.12 Ethylene 1.94 7.00 0.30 Ethane 14.94 8.06 0.30 Propylene + Propane 56.38 50.42 1.86 C4HC 10.78 30.72 2.02 Hexane 0.01 0.89 95.29 Benzene 1.90 0.43 0.12 Toluene 2.76 0.55 0.00 Ethylbenzene 0.15 0.00 0.00 P-Xylene 0.37 0.00 0.00 m-Xylene 0.82 0.00 0.00 o-Xylene 0.40 0.00 0.00 Ethyltoluenes 0.15 0.00 0.00 trimethylbenzene 0.19 0.00 0.00 C-10 and others 1.73 0.00 0.00 n-hexane conversion wt % 99.99 99.11 4.71 Total aromatics 8.47 0.97 0.12

Example 8

(42) The zeolite H-ZSM-5 having SAR of 23 was taken as the base material and different concentrations of Gallium was added as promoter and tested under the reaction conditions as listed in example 1. More particularly, in example 8a, H-ZSM-5 having SAR of 23 was taken as the base material and 1% Gallium was added as promoter; in example 8b, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Ga was added as promoter; in example 8c, H-ZSM-5 having SAR of 23 was taken as the base material and 6% Ga was added as promoter and in example 8d, H-ZSM-5 having SAR of 23 was taken as the base material and 8% Ga was added as promoter. The results are provided in Table 8.

(43) TABLE-US-00008 TABLE 8 Product distribution (wt %) Ex. 8a Ex. 8b Ex. 8c Ex. 8d Methane 31.91 22.36 16.71 19.00 Ethylene 1.54 0.55 0.56 0.66 Ethane 15.41 10.98 9.67 11.90 Propylene + Propane 16.62 13.03 10.35 11.75 C4HC 0.55 0.27 0.22 0.24 Hexane 0.03 0.05 0.06 0.05 Benzene 12.20 13.33 18.21 15.66 Toluene 18.41 30.48 37.57 32.02 Ethylbenzene 0.11 0.18 0.11 0.10 P-Xylene 0.60 1.18 1.09 0.97 m-Xylene 1.41 2.59 2.46 2.09 o-Xylene 0.49 0.95 0.80 0.73 Ethyltoluenes 0.06 0.09 0.06 0.05 trimethylbenzene 0.09 0.14 0.06 0.10 C-10 and others 0.57 3.82 2.06 4.67 n-hexane conversion wt % 99.97 99.95 99.94 99.95 Total aromatics 33.94 52.76 62.43 56.40

Example 9

(44) The zeolite H-ZSM-5 having SAR of 23 was taken as the base material and different concentrations of Zinc was added as promoter and tested under the reaction conditions as listed in example 1. More particularly, in example 9a, 1-T-ZSM-5 having SAR of 23 was taken as the base material and 1% Zn was added as promoter; in example 9b, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Zn was added as promoter; in example 9c, H-ZSM-5 having SAR of 23 was taken as the base material and 3% Zn was added as promoter; in example 9d, H-ZSM-5 having SAR of 23 was taken as the base material and 4% Zn was added as promoter; and in example 9e, H-ZSM-5 having SAR of 23 was taken as the base material and 6% Zn was added as promoter. The results are provided in Table 9.

(45) TABLE-US-00009 TABLE 9 Product distribution (wt %) Ex. 9a Ex. 9b Ex. 9c Ex. 9d Ex. 9e Methane 7.23 4.55 4.55 5.70 13.34 Ethylene 2.25 0.73 0.73 0.16 0.19 Ethane 13.00 12.22 12.22 18.85 40.70 Propylene + Propane 37.68 21.93 21.93 16.58 17.81 C4HC 6.79 6.16 6.16 2.05 0.51 Hexane 0.07 0.53 0.53 0.61 0.02 Benzene 7.72 9.79 9.79 13.28 8.42 Toluene 16.36 23.64 23.64 26.24 11.60 Ethylbenzene 0.38 0.89 0.89 0.23 0.16 P-Xylene 1.19 3.23 3.23 3.40 1.30 m-Xylene 2.81 7.15 7.15 7.80 2.85 o-Xylene 1.20 3.26 3.26 3.50 1.28 Ethyltoluenes 0.11 0.81 0.81 0.20 0.03 trimethylbenzene 0.13 0.88 0.88 0.52 0.28 C-10 and others 3.06 4.23 4.23 0.88 1.51 n-hexane conversion 99.93 99.47 99.47 99.39 99.98 wt % Total aromatics 32.97 53.87 53.87 56.05 27.43

Example 10

(46) The zeolite H-ZSM-5 having SAR of 23 was taken as the base material and different concentrations of promoters was added and tested under the reaction conditions as listed in example 1. More particularly, in example 10a, H-ZSM-5 having SAR of 23 was taken as the base material and 0.5% potassium and 2% Zn were added as promoters; in example 10b, H-ZSM-5 having SAR of 23 was taken as the base material and 0.5% magnesium and 2% Zn were added as promoters; and in example 10c, H-ZSM-5 having SAR of 23 was taken as the base material and 0.5% molybdenum and 2% Zn were added as promoters. The results are provided in Table 10.

(47) TABLE-US-00010 TABLE 10 Product distribution (wt %) Ex. 10c Ex. 10d Ex. 10e Methane 8.89 7.47 10.37 Ethylene 0.61 0.30 0.45 Ethane 37.55 22.29 34.17 Propylene + Propane 41.08 22.75 29.75 C4HC 8.74 3.24 3.28 Hexane 0.03 0.12 0.02 Benzene 2.31 10.42 6.35 Toluene 0.80 19.34 12.19 Ethylbenzene 0.00 0.30 0.05 P-Xylene 0.00 2.49 0.44 m-Xylene 0.00 5.50 1.62 o-Xylene 0.00 2.51 0.74 Ethyltoluenes 0.00 0.13 0.00 trimethylbenzene 0.00 0.60 0.00 C-10 and others 0.00 2.54 0.56 n-hexane conversion wt % 99.97 99.88 99.98 Total aromatics 3.11 43.83 21.96

Example 11

(48) The zeolite H-ZSM-5 having SAR of 23 was taken as the base material and different concentrations of promoters was added and tested under the reaction conditions as listed in example 1. More particularly, in example 11a, H-ZSM-5 having SAR of 23 was taken as the base material and 1% Zn and 2% Ga were added as promoters; in example 11b, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Zn and 2% Ga were added as promoters; in example 11c, H-ZSM-5 having SAR of 23 was taken as the base material and 2% Zn and 4% Ga were added as promoters; and in example 11d, H-ZSM-5 having SAR of 23 was taken as the base material and 4% Zn and 4% Ga were added as promoters. The results are provided in Table 11.

(49) TABLE-US-00011 TABLE 11 Product distribution (wt %) Ex. 11a Ex. 11b Ex. 11c Ex. 11d Methane 11.12 9.48 7.01 6.02 Ethylene 1.02 1.41 1.90 1.21 Ethane 8.54 9.26 9.04 6.70 Propylene + Propane 17.75 23.95 33.75 22.74 C4HC 0.93 4.49 15.51 5.40 Hexane 0.13 0.11 0.87 0.42 Benzene 14.27 11.35 5.55 10.83 Toluene 27.52 23.22 14.40 26.01 Ethylbenzene 0.41 0.57 0.74 0.64 P-Xylene 2.91 2.92 2.06 3.27 m-Xylene 6.41 6.38 4.25 7.07 o-Xylene 3.00 2.92 1.90 3.20 Ethyltoluenes 0.31 0.46 0.72 0.60 trimethylbenzene 0.56 0.58 0.40 0.70 C-10 and others 5.11 2.90 1.90 5.20 n-hexane conversion wt % 99.87 99.89 99.13 99.58 Total aromatics 60.50 51.31 31.91 57.51

Example 12

(50) The zeolite crystals of example 11a were formed as extrudates with a diluent such as alumina along with peptizing agent such as nitric acid and fillers such as clays to obtain extrudates. Such extrudates were tested under the reaction conditions as listed in example 1. Particularly, in example 12a, 70% of zeolite crystals of example 11a were mixed with 30% of diluents and fillers and formed as extrudates and tested; in example 12b, 30% of zeolite crystals of example 11a were mixed with 30% of diluents and fillers and formed as extrudates and tested; in example 12c, 40% of zeolite crystals of example 11a were mixed with 60% of diluents and fillers and formed as extrudates and tested; and in example 12d, 60% of zeolite crystals of example 11a were mixed with 40% of diluents and fillers and formed as extrudates and tested. The results are provided in Table 12.

(51) TABLE-US-00012 TABLE 12 Product distribution (wt %) Ex. 12a Ex. 12b Ex. 12c Ex. 12d Methane 5.98 5.30 8.66 4.54 Ethylene 1.88 4.92 2.21 4.46 Ethane 3.84 3.54 4.80 3.61 Propylene + Propane 19.02 19.81 17.68 18.83 C4HC 7.51 14.65 3.06 11.80 Light alkanes (C-5-HC) 0.50 1.53 0.18 3.82 Benzene 10.22 7.34 12.89 8.60 Toluene 27.56 23.11 28.02 23.18 Ethylbenzene 0.80 1.02 0.65 0.98 P-Xylene 3.74 3.42 3.30 3.49 m-Xylene 8.19 7.07 7.25 7.27 o-Xylene 3.70 3.05 3.36 3.19 Ethyltoluenes 0.85 1.01 0.60 1.00 trimethylbenzene 1.03 0.90 0.75 0.92 C-10 and others 5.18 3.34 6.60 4.32 n-hexane conversion wt % 99.50 98.47 99.82 96.18 Total aromatics 61.27 50.25 63.42 52.95

Example 13

(52) The zeolite crystals of example 11a were taken as base material and further loaded with one or more transition metal as promoter and tested under the reaction conditions as listed in example 1. Particularly, in example 13a, zeolite crystals of example 11a were loaded with 0.5% Cerium; in example 13b, zeolite crystals of example 11a were loaded with 0.5% Tin; in example 13c, zeolite crystals of example 11a were loaded with 0.5% Chromium; and in example 13d, zeolite crystals of example 11a were loaded with 0.5% of Cerium, 0.5% of Tin and 0.5% of Chromium. The results are provided in Table 13.

(53) TABLE-US-00013 TABLE 13 Product distribution (wt %) Ex. 13a Ex. 13b Ex. 13c Ex. 13d Methane 4.64 4.67 11.11 9.60 Ethylene 1.02 1.62 1.13 2.65 Ethane 2.59 2.45 5.91 7.76 Propylene + Propane 11.25 11.74 22.73 17.40 C4HC 8.48 13.57 5.44 7.99 Light alkanes (C-5-HC) 2.17 2.14 0.18 0.55 Benzene 28.80 20.78 11.64 11.24 Toluene 28.76 28.55 23.11 23.17 Ethylbenzene 0.41 0.77 0.39 0.79 P-Xylene 2.22 2.55 2.90 3.10 m-Xylene 4.83 5.45 6.41 7.04 o-Xylene 2.12 2.36 2.90 3.07 Ethyltoluenes 0.27 0.55 0.42 0.76 trimethylbenzene 0.44 0.75 0.71 1.06 C-10 and others 2.00 2.06 5.02 3.81 n-hexane conversion wt % 97.83 97.86 99.82 99.45 Total aromatics 69.85 63.82 53.51 54.03

Example 14

(54) In the following example, the effect of different feedstock was studied over the catalyst composition listed in example 11a. More particularly, in example 14a, the catalyst composition as described in example 11a was used with respect to a feedstock comprising n-pentane; in example 14b, the catalyst composition as described in example 11a was used with respect to a feedstock comprising a mixture of n-pentane and n-hexane (in a ratio of 1:1); in example 14c, the catalyst composition as described in example 11a was used with respect to a feedstock comprising n-hexane; in example 14d, the catalyst composition as described in example 11a was used with respect to a feedstock comprising n-heptane (in a ratio of 1:1); in example 14e, the catalyst composition as described in example 11a was used with respect to a refinery light naphtha denoted by FS-01 whose composition details are provided in Table 14; and in example 14f, the catalyst composition as described in example 11a was used with respect to a refinery light naphtha denoted by FS-02 whose composition details are provided in Table 14. The results of these experiments are provided in Table 15.

(55) TABLE-US-00014 TABLE 14 Reactant distribution (wt %) FS-01 FS-02 C4 0.41 Isopentane 31.88 (C5) 18.38 n-pentane 24.11 2-methyl pentane 56.37 (C6) 12.92 n-hexane 21.04 Methyl cyclopentane 13.31 Cyclohexane 9.99 heptane 11.34 0.27

(56) TABLE-US-00015 TABLE 15 Product distribution (wt %) Catalyst: Example: 11a Feed Ex. 14a Ex. 14b Ex. 14c Ex. 14d Ex. 14e Ex. 14f Methane 10.73 11.02 6.86 14.26 7.73 8.96 Ethylene 1.23 1.29 1.28 2.67 1.23 2.24 Ethane 8.67 8.65 5.09 8.07 4.39 8.11 Propylene + 23.84 17.89 14.86 22.45 17.64 24.96 Propane C4HC 5.65 2.10 1.62 2.77 3.70 4.03 Light alkanes 0.22 0.17 0.11 0.13 0.53 0.33 (C-5-HC) Benzene 9.24 13.99 16.81 12.68 11.32 10.03 Toluene 21.41 27.23 31.50 21.90 28.11 22.40 Ethylbenzene 0.44 0.53 0.44 0.22 0.71 0.54 P-Xylene 2.90 2.86 3.24 1.89 3.85 2.58 m-Xylene 6.39 6.25 7.14 5.01 8.45 6.59 o-Xylene 2.89 2.87 3.36 2.22 3.86 2.87 Ethyltoluenes 0.49 0.39 0.34 0.27 0.78 0.61 trimethyl- 0.62 0.49 0.63 0.38 1.69 0.59 benzene C-10 and 5.26 4.28 6.73 5.08 6.01 5.15 others n-hexane con- 99.78 99.83 99.89 99.87 99.47 99.67 version wt % Total aromatics 49.65 58.89 70.19 49.66 64.79 51.36

Example 15

(57) In the following example, the effect of carrier different feedstock was studied over the catalyst composition listed in example 11a. More particularly, in example 15a, no carrier gas was used; in example 15b, a carrier gas comprising Nitrogen was used, wherein the nitrogen to hydrocarbon ratio was maintained at 5; in example 15c, a carrier gas comprising Nitrogen and hydrogen (in a ratio of 1:1) was used, wherein the carrier gas to hydrocarbon ratio was maintained at 5; in example 15d, a carrier gas comprising Nitrogen and hydrogen (in a ratio of 4:1) was used, wherein the carrier gas to hydrocarbon ratio was maintained at 5; and in example 15e, a carrier gas comprising Nitrogen and hydrogen (in a ratio of 1:4) was used, wherein the carrier gas to hydrocarbon ratio was maintained at 5. The results of these experiments are provided in Table 16.

(58) TABLE-US-00016 TABLE 16 Product distribution (wt %) Ex. 15a Ex. 15b Ex. 15c Ex. 15d Ex. 15e Methane 8.87 6.86 8.64 7.26 8.07 Ethylene 1.39 1.28 2.15 2.35 2.21 Ethane 6.92 5.09 8.10 7.13 7.30 Propylene+ 18.24 14.86 30.85 28.94 30.96 C4HC 2.87 1.62 10.51 11.76 13.85 Hexane 0.30 0.11 0.25 0.28 0.24 Benzene 12.57 16.81 7.39 7.67 6.72 Toluene 27.32 31.50 18.25 19.39 17.18 Ethylbenzene 0.61 0.44 0.70 0.77 0.64 P-Xylene 3.34 3.24 2.41 2.56 2.24 m-Xylene 7.27 7.14 5.31 5.62 4.94 o-Xylene 3.34 3.36 2.42 2.55 2.25 Ethyltoluenes 0.57 0.34 0.63 0.75 0.59 trimethylbenzene 0.70 0.63 0.16 0.57 0.50 C-10 and others 5.69 6.73 2.24 2.39 2.31 n-hexane 99.70 99.89 99.75 99.72 99.76 Total aromatics 61.41 70.19 39.51 42.28 37.37

Example 16

(59) In the following example, the effect of carrier different feedstock was studied over the catalyst composition listed in example 11a. More particularly, in example 16a, hydrogen was used as a carrier gas and a ratio between the carrier gas to the hydrocarbon was varied between about 0 to 2; in example 16b, nitrogen was used as a carrier gas and a ratio between the carrier gas to the hydrocarbon was varied between about 0 to 15. The results of these experiments are shown in the form of FIG. 1. More particularly, curve 100 sows the variation in terms of production of aromatic yield for different ratios of hydrogen to hydrocarbon feedstock, when hydrogen is used as the carrier gas and curve 200 shows the variation in terms of production of aromatic yield for different ratios of nitrogen to hydrocarbon feedstock, when nitrogen is used as the carrier gas.

(60) From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.