DESC:FIELD
The present disclosure relates to a catalyst composition for catalytic oxidative dehydrogenation of hydrocarbons and process for preparing the same.
BACKGROUND
Alkenes can be produced by oxidative dehydrogenation of hydrocarbons. 1,3-Butadiene is an important industrial alkene, which is commercially used for the preparation of polymers, for preparation of synthetic rubber, and as an intermediate in petrochemical industry.
1,3-Butadiene can be prepared by catalytic oxidative dehydrogenation of petroleum feedstocks comprising C4 hydrocarbons. However, such catalyst compositions are associated with drawbacks such as high cost, high attrition rate during cracking process, coking and low yield of butadiene.
There is, therefore, felt a need to develop an inexpensive catalyst composition for catalytic oxidative dehydrogenation of hydrocarbons, particularly for the preparation of 1,3-butadiene in high yield from C4 hydrocarbons.
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 catalyst composition for catalytic oxidative dehydrogenation of hydrocarbons.
Another object of the present disclosure is to provide a catalyst composition for the preparation of 1,3-butadiene by catalytic oxidative dehydrogenation of C4 hydrocarbons.
Yet another object of the present disclosure is to provide an inexpensive catalyst for the preparation of 1,3-butadiene in high yield by catalytic oxidative dehydrogenation of C4 hydrocarbons.
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 one aspect, the present disclosure provides a catalyst composition comprising shaped articles made of pulverized and peptized particles of mixed oxide of iron and zinc which are extruded and calcined.
The molar ratio of iron to zinc is in the range of 10:1 to 1:10.
The mixed oxide is at least one selected from the group consisting of spinel, hematite, and magnetite.
Preferbaly, the molar ratio of iron to zinc is greater than 2:1.
The mixed oxide is selected from the group consisting of spinel, hematite, and magnetite. The shaped article is in the form of at least one shape selected from the group consisting of cylinder, sphere, pellet, rod, tube, star, trilobe, tetralobe, disk, ring-shaped, donut, honeycomb, cup, and an irregular shape.
The shaped article is cylindrical in shape and has average diameter in the range of 0.5 mm to 5 mm.
The crushing strength of the catalyst composition is in the range of 4.0 KgF to 7.0 KgF.
In an embodiment of the present disclosure, the mixed oxide consists of zinc ferrite in spinel from and iron oxide in hematite form, wherein the amount of the spinel form is in the range of 75 wt% to 77 wt%, and the amount of the hematite form is in the range of 23 wt% to 25%.
In an embodiment of the present disclosure, the shaped articles further comprises particles of alumina, wherein the amount of alumina is in the range of 2 weight % to 25 weight% of the catalyst composition. The catalyst compositions comprising alumina have crushing strength in the range of 3.0 KgF to 5.5 KgF.
In second aspect, the present disclosure provides a process for preparing the catalyst composition. The process comprises the following steps:
A source of iron and a source of zinc are mixed with water to obtain a first mixture.
Aqueous alkali solution is added to the first mixture under stirring till the pH of the mixture is in the range of 9 to 12. The resultant mixture is further stirred for a period in the range of 0.5 hour to 12 hours to obtain a dispersion.
The dispersion is aged for a period in the range of 0.5 hour to 48 hours to obtain an aged dispersion.
Solid is separated from the aged dispersion, and the separated solid is washed to obtain a residue, and the residue is dried to obtain a dried residue.
The dried residue is pulverized, sieved, and calcined to obtain a mixed oxide of iron and zinc.
The mixed oxide is admixed with at least one peptizing agent, and water to obtain an admixture, followed by pugging the admixture to obtain a dough, and aging the dough.
Shaped bodies are extruded from the aged dough and the extruded shaped bodies are calcined at a temperature in the range of 160 ?C to 700 ?C for a time period in the range of 1 hour to 24 hours to obtain the catalyst composition.
In accordance with one embodiment of the present disclosure, the admixture further comprises alumina.
The source of iron is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of iron. The source of zinc is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of zinc.
The alkali is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, and ammonium hydroxide.
The peptizing agent is at least one organic acid selected from the group consisting of formic acid and acetic acid.
In third aspect, the present disclosure provides a process for catalytic oxidative dehydrogenation of hydrocarbons. The process comprises the following steps:
A hydrocarbon is mixed with an oxidant, and a fluid medium to obtain a mixture.
The mixture is preheated to a temperature in the range of 100 ?C to 500 ?C to obtain a heated mixture.
A column is packed with the catalyst composition of the present disclosure, and the packed column is heated and maintained at a temperature in the range of 100 ?C to 500 ?C.
The heated mixture is passed with the heated packed column at a temperature in the range of 100 ?C to 500 ?C at a predetermined pressure to obtain a product containing dehydrogenated hydrocarbons.
The oxidant is at least one selected from the group consisting of oxygen, and air.
The fluid medium is at least one selected from the group consisting of steam, nitrogen, methane and carbon dioxide.
In one embodiment of the present disclosure, the hydrocarbon is a C4 hydrocarbon, and the dehydrogenated hydrocarbon is butadiene. The yield of butadiene is in the range of 67% to 81% mol/mol.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which
Figure-1 illustrates the X-ray diffraction (XRD) spectra of three catalyst compositions consisting of zinc ferrite in spinel form and iron oxide in hematite form, wherein peaks identified by dotted lines relate to Zinc Ferrite spinel form and peaks identified by * relate to a-Fe2O3 in hematite form.
DETAILED DESCRIPTION
1,3-Butadiene is an important industrial intermediate. 1,3-Butadiene can be prepared by catalytic oxidative dehydrogenation of petroleum feedstocks comprising C4 hydrocarbons. However, such catalyst compositions are associated with drawbacks such as high cost, high attrition rate during cracking process, and low yield of butadiene. The present disclosure envisages an inexpensive catalyst composition for the preparation of 1,3-butadiene in high yield from a C4 hydrocarbon by catalytic oxidative dehydrogenation.
In one aspect, the present disclosure provides a catalyst composition comprising shaped articles made of pulverized and peptized particles of mixed oxide of iron and zinc which are extruded and calcined.
The molar ratio of iron to zinc is in the range of 10:1 to 1:10.
Typically, the molar ratio of iron to zinc is in the range of 1:1 to 4.5:1. In accordance with an exemplary embodiment of the present disclosure, a mixed oxide is prepared using the molar ratio of iron to zinc of 2:1. The mixed oxide obtained is zinc ferrite.
Preferably, the molar ratio of iron to zinc is greater than 2:1.
The mixed oxide is at least one selected from the group consisting of spinel, hematite, and magnetite.
In accordance with one embodiment of the present disclosure, the mixed oxide consists of zinc ferrite in spinel from and iron oxide in hematite form, wherein the amount of the spinel form is in the range of 75 wt% to 77 wt%, and the amount of the hematite form is in the range of 23 wt% to 25%.
In accordance with an embodiment of the present disclosure, the catalyst composition is prepared without using a binder.
The catalyst composition of the present disclosure is in the form of at least one shape selected from the group consisting of cylinder, sphere, pellet, rod, tube, star, trilobe, tetralobe, disk, ring-shaped, donut, honeycomb, cup, and an irregular shape.
Crushing strength of the catalyst composition of the present disclosure in the form of shape bodies is high.
The catalyst composition of the present disclosure has crushing strength in the range of 4.0 KgF to 7.0 KgF.
In accordance with one embodiment of the present disclosure, the shaped article is cylindrical in shape and has average diameter in the range of 0.5 mm to 5 mm.
Due to the high crushing strength, the catalyst composition of the present disclosure has high stability and low attrition rate. Further, due to high crushing strength, the catalyst composition of the present disclosure can withstand high pressure.
In accordance with another embodiment of the present disclosure, the shaped articles further comprises particles of alumina as a binder, wherein the amount of alumina is in the range of 2 weight % to 25 weight% of the catalyst composition. The catalyst composition comprising alumina as a binder has crushing strength in the range of 3.0 KgF to 5.5 KgF.
It is observed that the crushing strength of the catalyst composition prepared without a binder has higher crushing strength as compared to the catalyst composition prepared using a binder. The catalyst composition prepared without a binder is also economical.
In second aspect, the present disclosure provides a process for preparing the catalyst composition. The process comprises the following steps:
A source of iron and a source of zinc are mixed with water to obtain a first mixture.
Aqueous alkali solution is added to the first mixture under stirring till the pH of the mixture is in the range of 9 to 12. The resultant mixture is stirred for a period in the range of 0.5 hour to 12 hours to obtain a dispersion.
The dispersion is aged for a period in the range of 0.5 hour to 48 hours to obtain an aged dispersion.
Solid is separated from the aged dispersion. The separated solid is washed to obtain a residue. The residue is dried to obtain a dried residue.
The dried residue is pulverized, sieved, and calcined to obtain a mixed oxide of iron and zinc.
The mixed oxide is mixed with at least one peptizing agent, and water to obtain an admixture followed by pugging the admixture to obtain a dough, and aging the dough.
Shaped bodies are extruded from the aged dough, followed by calcining the extruded shaped bodies at a temperature in the range of 160 ?C to 700 ?C for a time period in the range of 1 hour to 24 hours to obtain the catalyst composition.
In accordance with an embodiment of the present disclosure, the admixture further comprises alumina.
The source of iron is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of iron.
In accordance with one embodiment of the present disclosure, the source of iron is ferric nitrate.
The source of zinc is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of zinc.
In accordance with one embodiment of the present disclosure, the source of zinc is zinc nitrate.
The molar ratio of the source of iron to the source of zinc is in the range of 10:1 to 1:10.
In accordance with one embodiment of the present disclosure, the molar ratio of the source of iron to the source of zinc is 2:1.
The alkali is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, and ammonium hydroxide.
In accordance with one embodiment of the present disclosure, the alkali is sodium hydroxide.
In the step of separating solid from the aged dispersion, washing of solid is carried out in portions till the filtrate obtained on washing with a portion has a pH in the range of 6.5 to 7.5.
The residue comprises mixed hydroxide of iron and zinc.
The peptizing agent is at least one organic acid selected from the group consisting of formic acid, and acetic acid.
In accordance with one embodiment of the present disclosure, the peptizing agent is acetic acid.
The process of the present disclosure uses inexpensive and easily available raw materials. Further, the process of the present disclosure uses a simple process for preparation of the catalyst composition.
In third aspect, the present disclosure provides a process for catalytic oxidative dehydrogenation of hydrocarbons in the presence of the catalyst composition of the present disclosure. The process comprises the following steps:
A hydrocarbon is mixed with an oxidant, and a fluid medium to obtain a mixture.
The mixture is preheated to a temperature in the range of 100 ?C to 500 ?C to obtain a heated mixture.
A column is packed with the catalyst composition of the present disclosure, and the packed column is heated and maintained at a temperature in the range of 100 ?C to 500 ?C.
The heated mixture is passed through the heated packed column at a temperature in the range of 100 ?C to 500 ?C at a predetermined pressure to obtain a product containing dehydrogenated hydrocarbons.
In accordance with one embodiment of the present disclosure, the hydrocarbon is C4 raffinate.
The oxidant is at least one selected from the group consisting of oxygen, and air. The mole ratio of the oxidant to the hydrocarbon is in the range of 1:0.75 to 1:1.5.
In accordance with the embodiments of the present disclosure, the fluid medium is at least one selected from the group consisting of steam, nitrogen, methane and carbon dioxide.
In accordance with an exemplary embodiment of the present disclosure, the fluid medium is superheated steam.
The mole ratio of the fluid medium to hydrocarbon is in the range of 5:1 to 25:1.
In accordance with one embodiment of the present disclosure, the reactor is isothermal continuous flow fixed bed reactor.
In accordance with an exemplary embodiment of the present disclosure, the hydrocarbon is C4 hydrocarbon, and the dehydrogenated hydrocarbon is butadiene. The yield of butadiene is in the range of 67% to 81% mol/mol. The catalyst composition of the present application has high catalytic activity, which is evident from the high amount of product formed per kilogram of catalyst per hour.
Thus, the catalytic composition of the present disclosure provides butadiene in high yield.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for 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.
Experiments:
Experiment 1: Preparation of the mixed oxide of iron and zinc
Ferric nitrate (2 mol) and zinc nitrate (1 mol) were dissolved in double distilled water under stirring to obtain a first mixture. Aqueous sodium hydroxide solution (3 molar) was added drop wise to the first mixture till the pH of the resultant solution was 10. During this step, a resultant mixture comprising solid mass gradually formed. The resultant mixture was stirred vigorously for 2 hours to obtain a dispersion. The dispersion was aged for 15 hours to obtain an aged dispersion. Solid was separated from the aged dispersion, and the separated solid was washed with hot distilled water to remove excess alkali and to obtain a residue. Washing was carried out in portions, till the filtrate obtained upon washing by a portion showed a pH of 7. The residue thus obtained was a mixed hydroxide of iron and zinc.
The residue was dried in an oven at 160 °C for 15 hours. The dried residue was pulverized and sieved to obtain a fine powder, and calcined in a muffle furnace for 6 hours at 650°C to obtain the mixed oxide of iron and zinc.
The mixed oxide was characterized using inductively coupled plasma (ICP) analysis and X-ray powder diffraction (P-XRD) analysis. The Fe/Zn ratio of 2 was determined by ICP analysis. The P-XRD of the mixed oxide powder obtained from experiment 1 showed pure zinc ferrite spinel phase.
A series of experiments for the preparation of the mixed oxide were carried out using the procedure described in experiment 1, while varying the ratio of iron to zinc.
It is observed that the mixed oxide having Fe/Zn molar ratio equal to or less than 2 showed pure zinc ferrite spinel phase. Whereas, the mixed oxide powder having Fe/Zn molar ratio greater than 2 showed zinc ferrite spinel phase along with an additional peaks of a-Fe2O3 hematite phase.
Figure-1 illustrates the X-ray diffraction (XRD) spectra of three catalyst compositions consisting of zinc ferrite in spinel form and iron oxide in hematite form, wherein peaks identified by dotted lines relate to Zinc Ferrite spinel form and peaks identified by * relate to a-Fe2O3 in hematite form.
Experiment 2: Preparation of cylindrical extrudates comprising the mixed oxide and binder
Three catalyst compositions were prepared using different proportions of the mixed oxide and binder, as shown in Table 1, using the procedure given below.
The mixed oxide obtained in experiment 1 and alumina as binder were mixed and the resultant mixture was pulverized in a mortar pestle. The pulverized resultant mixture was admixed with acetic acid and water to obtain an admixture and a dough was prepared from the admixture by pugging. Cylindrical extrudates were prepared from the dough using a manual sodium press having dyes of different sizes in the range of 1.5 mm to 3 mm. The cylindrical extrudates were dried at 160°C for 15 hours, followed by calcination at 650°C for 6 hours to obtain the catalyst composition. Crushing strength of various catalyst compositions are shown in Table 1.

Table 1: Crushing strength of the catalyst composition
Catalyst Composition (ratio of metal oxide powder/ binder) Crushing Strength (KgF)
Composition-1 77/23 3.77
Composition-2 85/15 5.17
Composition-3 95/5 4.75

It is evident from Table-1 that the catalyst compositions of the present disclosure have high crushing strength.
Experiment 3: Preparation of cylindrical extrudates of the mixed oxide without use of a binder
Cylindrical extrudates of the metal oxide obtained in experiment-1 were prepared directly, i. e. without mixing with a binder, using the process mentioned herein above for Experiment 2.
The crushing strength of the cylindrical extrudates of the metal oxide alone was found to be in the range of 4.5 KgF to 6.5 KgF.
Thus, the cylindrical extrudates of the metal oxide alone (without use of any binder) have high crushing strength.

Experiment 4:
The oxidative dehydrogenation of C4 hydrocabon was carried out using a column containing catalyst bed of 10 cm bed length of composition-1 obtained from Experiment 2 in a continuous flow fixed-bed reactor having the dimensions shown in Table 2.
Table 2: Dimensions of reactor
Parameter Unit Value
Avarage size of cylindrical extrudates (diameter) mm 2.25
Reactor internal diameter (ID) cm 0.9
Reactor length cm 100
Catalyst bed length cm 10

The oxidative dehydrogenation was carried out in the presence of oxygen as an oxidant and steam as a fluid medium. Steam was used as a heat sink to remove exothermically generated heat. An electrically heated fluidized sand-bath system was used for maintaining a constant temperature in the reactor.
Prior to the catalytic reaction, the packed column was pretreated at 300 ?C for 1 hour with air. Pre-heated steam (175 ?C) was continuously fed into the reactor.
C4 hydrocarbon and oxygen were mixed with water vapour in a mixer; the mixture was preheated to 350 ?C. The preheated mixture was fed to the reactor, wherein a constant temperature of 350 ?C was maintained in the catalytic bed.
The product exiting the reactor was cooled, followed by separation of water from the cooled product using a condenser. The dehydrated product was analysed by gas chromatography (GC). The process parameters and results are shown in Table 3.
Similarly, experiments were carried out using composition-2 and composition-3 obtained in Experiment-2. The process parameters and results are shown in Table 3.
Table 3: Process parameters and Results
Entry Catalyst Reaction conditions % Butene Conversion % Selectivity for Butadiene % Butadiene Yield Mol. Of product/Kg catalyst/hour
1 Composition-1 T=350?C; P= 1.0 atm; C4 GHSV~450 h-1 ; O2/ C4 = 0.93 (n/n) and steam/C4 = 10 (n/n); catalyst volume = 6.36 cc 72 93 67 5.70
2 Composition-2 T=350?C; P= 1.0 atm; C4 GHSV~450 h-1 ; O2/ C4 = 0.93 (n/n) and steam/C4 = 10 (n/n); catalyst volume = 6.36 cc 86 82 71 6.00
3 Composition-3 T=350?C; P=1.0 atm; C4 GHSV~450 h-1 ; O2/ C4 = 1.22 (n/n) and steam/C4 = 18 (n/n); catalyst volume = 6.36 cc 86 94 81 6.88
* T = temperature, P = pressure, C4 GHSV = Gas hourly space velocity of C4 hydrocarbon, O2/C4 = molar ratio of oxidant to C4 hydrocarbon, steam/C4 = molar ratio of steam to C4 hydrocarbon, cc = cubic centimeter, n/n = mol/mol.
It is evident from Table 3 that the catalyst composition of the present application dehydrogenates the C4 hydrocarbons and provides butadiene with a yield in the range of 67% to 81% mol/mol. The catalyst composition of the present application has high catalytic activity, which is evident from the high amount of product formed per kilogram of catalyst per hour.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
- an inexpensive catalyst composition for catalytic oxidative dehydrogenation of hydrocarbons;
- a catalyst composition having high particle crushing strength; and
- a catalyst composition when employed for catalytic oxidative dehydrogenation provides butadiene in high yield.
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:1. A catalyst composition comprising shaped articles made of pulverized and peptized particles of mixed oxide of iron and zinc which are extruded and calcined.
2. The catalyst composition as claimed in claim 1, wherein the molar ratio of iron to zinc is in the range of 10:1 to 1:10.
3. The catalyst composition as claimed in claim 1, wherein the molar ratio of iron to zinc is greater than 2:1.
4. The catalyst composition as claimed in claim 1, wherein the mixed oxide is at least one selected from the group consisting of spinel, hematite, and magnetite.
5. The catalyst composition as claimed in claim 1, wherein the mixed oxide consists of zinc ferrite in spinel form and iron oxide in hematite form, wherein the amount of the spinel form is in the range of 75 wt% to 77 wt%, and the amount of the hematite form is in the range of 23 wt% to 25%.
6. The catalyst composition as claimed in claim 1, wherein the shaped article is in the form of at least one shape selected from the group consisting of cylinder, sphere, pellet, rod, tube, star, trilobe, tetralobe, disk, ring-shaped, donut, honeycomb, cup, and an irregular shape.
7. The catalyst composition as claimed in claim 1, wherein the shaped article is cylindrical in shape and has average diameter in the range of 0.5 mm to 5 mm.
8. The catalyst composition as claimed in claim 1, having crushing strength in the range of 4.0 KgF to 7.0 KgF.
9. The catalyst composition as claimed in claim 1, wherein the shaped articles further comprises particles of alumina, wherein the amount of alumina is in the range of 2 weight % to 25 weight% of the catalyst composition.
10. The catalyst composition as claimed in claim 9, having crushing strength in the range of 3.0 KgF to 5.5 KgF.
11. A process for preparing the catalyst composition as claimed in claim 1, the process comprising the following steps:
- mixing at least one source of iron, and at least one source of zinc with water to obtain a first mixture;
- adding aqueous alkali solution to the first mixture, under stirring, till the pH of the first mixture is in the range of 9 to 12, and further stirring the resultant mixture for a period in the range of 0.5 hour to 12 hours to obtain a dispersion;
- aging the dispersion for a period in the range of 0.5 hour to 48 hours to obtain an aged dispersion;
- separating solid from the aged dispersion, and washing the separated solid to obtain a residue, followed by drying the residue to obtain a dried residue;
- pulverizing and sieving the dried residue, followed by calcining to obtain the mixed oxide of iron and zinc;
- admixing the mixed oxide with at least one peptizing agent, and water to obtain an admixture, followed by pugging the admixture to obtain a dough, and aging the dough; and
- extruding shaped bodies from the aged dough and calcining the extruded shaped bodies at a temperature in the range of 160 ?C to 700 ?C for a time period in the range of 1 hour to 24 hours to obtain the catalyst composition.
12. The process as claimed in claim 11, wherein the admixture further comprises alumina.
13. The process as claimed in claim 11, wherein the source of iron is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of iron, and the source of zinc is at least one salt selected from the group consisting of halides, nitrates, carbonates and acetate of zinc.
14. The process as claimed in claim 11, wherein the alkali is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, and ammonium hydroxide.
15. The process as claimed in claim 11, wherein the peptizing agent is at least one organic acid selected from the group consisting of formic acid, and acetic acid.
16. A process for catalytic oxidative dehydrogenation of hydrocarbon, the process comprising the following steps:
- mixing the hydrocarbon with at least one oxidant, and at least one fluid medium to obtain a mixture;
- preheating the mixture to a temperature in the range of 100 ?C to 500 ?C to obtain a heated mixture;
- packing a column with the catalyst composition as claimed in claim 1, heating and maintaining the packed column at a temperature in the range of 100 ?C to 500 ?C; and
- passing the heated mixture through the heated packed column at a temperature in the range of 100 ?C to 500 ?C at a predetermined pressure to obtain a product containing dehydrogenated hydrocarbon;
wherein the oxidant is at least one selected from the group consisting of oxygen, and air, and the fluid medium is at least one selected from the group consisting of steam, nitrogen, methane and carbon dioxide.
17. The process as claimed in claim 16, wherein the hydrocarbon is a C4 hydrocarbon, and the dehydrogenated hydrocarbon is butadiene, and wherein the yield of butadiene is in the range of 67% to 81% mol/mol.