Claims:WE CLAIM:
1. A process for preparing an inorganic support for a catalyst, said process comprising:
a. reacting a predetermined quantity of aluminium hydroxide with a dilute acid solution to obtain a mass;
b. pugging said mass to obtain a homogeneous dough;
c. extruding said homogeneous dough through an extruder with a die having a diameter in the range of 0.5 to 3 mm to obtain an extrudate;
d. chopping said extrudate into pieces of desired length to obtain chopped pieces;
e. passing said chopped pieces onto a spherodization unit to obtain spheres of desired size distribution;
f. drying said spheres at a temperature in the range of 100 oC to 150 oC to obtain dried spheres; and
g. calcining said dried spheres at a temperature in the range of 500 oC to 600 ?C for a time period in the range of 3 hours to 5 hours to obtain inorganic supports in the form of spherical beads of gamma alumina phase.
2. The process as claimed in claim 1, wherein said diluted acid is at least one selected from mineral acid and organic acid.
3. The process as claimed in claim 1, wherein the concentration of said dilute acid is in the range of 1 to 8%.

4. The process as claimed in claim 1, wherein the predetermined quantity of said aluminium hydroxide is in the range of 70 wt% to 80 wt%.

5. The process as claimed in claim 1, wherein the weight ratio of said aluminium hydroxide to said dilute acid solution is 10 : 80.

6. The process as claimed in claim 1, wherein the pugging of said mass in step b) is carried out for a time period in the range of 5 minutes to 20 minutes.

7. The process as claimed in claim 1, wherein said spherodization unit is having plate speed in the range of 300 rpm to 1400 rpm, air flow in the range of 0.5 to 3 kg and a temperature in the range of 20 oC to 40 oC.
, Description:FIELD
The present disclosure relates to a process for preparation of an inorganic support for a catalyst, particularly for CCR catalyst (Continuous catalyst regeneration catalyst).
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 indicate otherwise.
The term “merumarization” or “spherodization” refers to a rapid and flexible process where products are made into small spheres, or spheroids. Spheronized products are relatively dense, uniform in size and shape, and have defined surface characteristics.
The term “spherodization unit” as used herein refers to a mechanical system that enables both the development and industrial production of spherical particles.
The term “bead” as used herein refers to an object that is formed in spherical shapes with different sizes.
The term, “Instrument air” as used herein refers to a clean supply of compressed air that is free from particles and having low moisture content (100 ppm).
The term, “Peptization” as used herein refers to the process responsible for the formation of stable dispersion of colloidal particles in a dispersion medium.
The term, “Start of Run temperature” also referred as SOR temperature, as used herein refers the temperature at which the measurement of performance of the catalyst reaction starts.
The term, “End of Run temperature” also referred as EOR temperature, as used herein refers the temperature at which the measurement of performance of the catalyst reaction ends.
BACKGROUND
Form and shape of particles carry vital importance in industrial catalysts. Diffusion rate, pressure drop, and mechanical stability are dependent on the shape and size of the particles. Continuous catalyst regeneration (CCR) catalyst is required for naphtha reforming to enhance the octane number of gasoline and valuable aromatics such as benzene, toluene, and xylenes (BTX). In continuous catalyst regeneration (CCR) process, the mechanical strength, abrasion resistance and bulk density of the particles are equally important. Conventionally, the spherical catalyst support as well as other alumina support for CCR catalyst is generally prepared by oil drop technique using high purity alumina prepared by isopropoxide route (hydrolysis route). The oil drop technique/ process has many disadvantages such as being multistep process, cumbersome operation, exothermic reaction that leads to many environmental issues viz., release of oil vapour, corrosive vapour emission, and the like. Further, the gamma alumina spheres used in the preparation of CCR catalyst is not readily available.
Therefore, there is a need for a process that mitigates the drawbacks mentioned hereinabove about the oil drop process/technique.
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 process for preparing an inorganic support.
Another object of the present disclosure is to provide an environmentally friendly, simple, safe, and cost effective process for preparing an inorganic support for a catalyst.
Still another object of the present disclosure is to provide maneuverability of the inorganic support over the range of larger bulk density and porosity of the particles.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure relates to a process for preparing an inorganic support for a catalyst. The process comprises reacting a predetermined quantity of aluminium hydroxide with a dilute acid solution to obtain a mass. The so obtained mass is pugged to obtain a homogeneous dough. The homogeneous dough is extruded through an extruder with a die having a diameter of in the range of 0.5 to 3 mm, typically 1.5 mm to obtain an extrudate. The so obtained extrudate is chopped into pieces of desired length and the chopped pieces are then passed onto a spherodization unit to obtain spheres of desired size. The diameter distribution of the sphere is in the range of 1.6 mm to 2.0 mm. The spheres are then dried at a temperature in the range of 100 oC to 150 oC to obtain dried spheres. The dried spheres are then calcined at a temperature in the range of 500 oC to 600 ?C for a time period in the range of 3 hours to 5 hours to obtain inorganic supports comprising porous gamma alumina in the form of spherical beads.
DETAILED DESCRIPTION
Conventionally, spherical catalyst support as well as other alumina support are prepared by the oil drop process. The oil drop process has many disadvantages such as being a multistep process, cumbersome procedure, exothermic reaction and pose many safety issues viz., oil vapor, corrosive chemical vapor emission etc.
The present disclosure, therefore, envisages a process for preparing an inorganic support which overcomes the drawbacks stated in the prior art.
The present disclosure relates to a process for preparing an inorganic support for a catalyst, preferably CCR catalyst. The detailed process is given herein below:
Firstly, a predetermined quantity of aluminium hydroxide is reacted with a dilute acid solution to obtain a resultant mass.
The predetermined quantity of aluminium hydroxide used in the process can be in the range of 70 to 80 wt%
The acid is at least one selected from mineral acid and organic acid.
The concentration of the acid used in the acid solution can be in the range of 1 to 8 % acid concentration.
The weight ratio of the aluminium hydroxide to the dilute acid solution is 10 : 80.
The so obtained mass is pugged for a predetermined time period to obtain a homogeneous dough.
The predetermined time period used for pugging can be in the range of 10 to 20 minutes
The mass can be pugged by employing a rapid mixer granulator or a z-shaped kneader.
The homogeneous dough is extruded through an extruder with a die having a diameter in the range of 0.5 mm to 3 mm, typically 1.5 mm to obtain an extrudate. The so obtained extrudate is chopped into pieces of desired length such as 10 mm to 50 mm and then passed on to a spherodization unit to obtain spheres of desired size distribution.
Spherodization unit refers to a system that enables both the development and industrial production of spherical shapes with different sizes without introducing any impurities. Spheronization is a process of converting rod shaped particles to spherical beads under fludized condition by using rotating friction plate moving with high speed. The spheronization can be conducted at ambient temperature.
The so obtained sphere/spheroidite structure after spherodization is a microstructure that contains sphere-like cementitie particles.
The so obtained spheres are dried at a temperature in the range of 100oC to 150oC to obtain dried spheres. Typically, the drying is carried out at 120°C.
The dried spheres are then calcined at a temperature in the range of 500 oC to 600 ?C for a time period in the range of 3 hours to 5 hours in presence of instrument air to obtain the inorganic support comprising porous gamma alumina in the form of spherical shape beads.
In the present disclosure, the process for preparing the supports employ precipitated boehmite alumina (neutralization route) by adopting Merumerisation technique. This process is inexpensive, ecofriendly, safer and also offers the maneuverability over the range of bulk density and porosity. Various supports such as zeolite, TiO2, ZrO2 and SiO2 can also be prepared for heterogenous catalyst support for various refinery and petrochemical industries.
The process can be used for forming different types of catalysts and adsorbents. CCR catalyst can be prepared by using spherical alumina support obtained by the process of the present disclosure and exhibits the performance of catalyst is at par with the performance of catalyst prepared using commercially available alumina support.
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.
EXPERIMENTAL DETAILS:
Experiment 1: Preparation of an inorganic support in accordance with the process of the present disclosure
100 gm pseudoboehmite powder (containing 73% of Al2O3 and 27% H2O) was taken in a glass tray, having 66 g moisture content on powder basis. 11 g of nitric acid (containing pure nitric acid with 69% w/v concentration) was sprayed slowly on the powder with continuous mixing (of pseudobohemite powder and nitric acid) to obtain a mass. The spraying process was completed in 20 minutes. The so obtained mixture was kept for Peptization for 60 minutes. After 60 minutes of peptization, the mixture was transferred to a z-shaped kneader and kneaded at 61 rpm for 3 minutes followed by kneading at 140 rpm for 4 minutes to obtain a dough.
The so obtained dough was extruded through 1.5 mm die plate and the so obtained extrudates were dried in air for 30 minutes followed by spherodization to obtain a spherical particles. The spherical particles were dried at 120°C for 4 hours and the dried spheres were activated at 580 °C in a tubular furnace for 4 hours in the presence of dry air to obtain the inorganic support for catalyst.
Experiment 2:
Evaluation of the catalyst by using commercially available support and the inorganic support in accordance with the present disclosure.
15 gm of catalyst was charged in fixed bed reactor. The feed was passed in the form vapors over the catalyst in the fixed bed reactor. The reactor was maintained at the reaction conditions given below.
Normal operating conditions for evaluation of catalyst.
• Catalyst amount : 15 gm
• LHSV of feed (Liquid hour space velocity): 1.95 h-1,
• Pressure : 7.3 kg/cm2
• H2/HC ratio : 4
• Temperature : 521-540°C

Table 1

Commercially available support
(oil drop technique) Inorganic support in accordance with the present disclosure
(merumerisation technique)
Temp. C8 Aromatics Total Aromatics C5+ liquid Yield C8 Aromatics Total Aromatics C5+ liquid Yield
Start of Run temp (SOR TEMP) at 521 °C 39.5 77 88.5 38.8 77 87
End of Run temp (EOR TEMP) at 540 °C 25 42 88.4 25 42 88
HOS (Hours on stream) 300 300
It is evident from the table 1 that, the inorganic support used in the CCR catalyst gives similar amount of C8 aromatics, Total Aromatics and C5+ liquid Yield which is recorded at SOR conditions and EOR conditions.
The run length i.e., total hours on stream are recorded for the performance of the catalyst. It is evident from the results given in Table 1 that the performance of both the catalyst are comparable. The performance of the catalyst prepared by employing supports of the present disclosure is comparable with the commercial catalyst.
In view of the above, it is concluded that the process of the present disclosure is simple, safe, scalable, and commercially viable, and offers maneuverability of particles for the density in the range of 0.68 to 0.81 g/cc and porosity in the range of 0.47 to 0.58 cc/g, and shows similar performance as compared to commercial catalyst.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
? scalable and commercially viable process;
? a simple, safe, environment friendly and cost effective process for the preparation of an inorganic support; and
? offers maneuverability for larger density and porosity of particles and shows similar performance as compared to commercial catalysts.
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” or “a” 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.