Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION

(See Section 10 and Rule 13)

Title of invention:
A PROCESS FOR SYNTHESIZING TERTIARY AMYLBENZENE (TAB) AND A SYSTEM THEREOF

APPLICANT:
VINATI ORGANICS LIMITED
Having Address:
Vinati organics limited
Parinee Crescenzo, A Wing, 11th floor, 1102, G Block,
Behind MCA, Bandra Kurla Complex, Bandra (east), Mumbai 400051, Maharashtra, India.

The following specification particularly describes the invention and the manner in which it is to be performed.
CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
The present application does not claim priority from any other patent application.

TECHNICAL FIELD
The present subject matter, in general, relates to the field of organic chemistry. More particularly, the present subject matter relates to a process for synthesizing Tertiary Amyl benzene (TAB), and a system thereof.

BACKGROUND
Tertiary amyl benzene (TAB) is a clear aromatic flammable liquid that plays a key role in wide spectrum of chemical processes. It is a crucial intermediate in the production of hydrogen peroxide, which is a colourless liquid usually produced as an aqueous solution. It is fundamentally known that hydrogen peroxide has numerous applications as an oxidizer, bleaching agent, and antiseptic in different sectors. TAB is also used for the preparation of 2-anthraquinones, a chemical routinely used for medical applications as a laxative, antimicrobial, and anti-inflammatory agent. Further, TAB serves as a building block in the synthesis of amorolfine, a potent antifungal API (active pharmaceutical ingredient) that works by preventing fungi producing ergosterol, an essential component of fungal cell membranes. In addition to its contribution in medical industry, when added into rechargeable lithium-ion batteries, TAB prevents overheating, fire, and explosion. It is known that TAB is a crucial component of the electrolytes in lithium-ion batteries that helps to prevent overcharging in these batteries, thereby helping to eliminate the dangers of fire and explosion associated with over charging.
The catalytic process of TAB synthesis mainly includes acid catalysis and base catalysis. The acid catalysis method essentially involves the Friedel-Crafts alkylation of benzene using tert-amyl alcohol isoprene, and tert-pentane chloride catalysed by an acid catalyst, such as sulfuric acid and aluminium trichloride. The alkali catalysis process is mainly side-chain alkylation, with alkali metal or alkali metal hydride used as its catalyst. However, the key problem in technology of tertiary amyl benzene synthesis technique is to control the ratio of isomer in the product. The state of art further discloses the implementation of molecular sieve catalysts to catalyse the synthesis of TAB from benzene and isoprene. However, catalyst deactivation and large amounts of by-product formation pose a major challenge in tertiary amyl benzene synthesis. In addition to this, the conventional methods for synthesizing TAB also display loss of reactants that effectually increase the overall cost of the process.
Due to the constant overwhelming requirement of TAB in numerous industries, and in pursuance of challenges above mentioned, the inventors of the instant disclosure were motivated to devise an improved system and process for curbing side reactions, and increasing the overall selectivity, and purity of the final product.
Considering this, the instant disclosure discloses an improved system and process to achieve high purity and high selectivity tertiary amyl benzene product that minimizes the need for further extensive processing and simplifies the overall procedure. The instant disclosure further relates to an application of a catalyst composition that exhibits efficient catalytic activity. The instant disclosure also discloses recovery and reuse of spent reactants and catalyst(s) described in the instant invention.
SUMMARY
An embodiment of the instant disclosure relates to a process for synthesizing Tertiary-Amyl benzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry; said process comprising, drying a catalyst carrier using a vacuum dryer and adding a catalyst to the dried catalyst carrier to form a mixture; preparing a catalytic composition in a catalyst preparation tank using the dried catalyst carrier; adding the catalyst slurry, cumene and the gasified ethylene to the agitator to form a reaction mixture; neutralizing the reaction mixture to remove residual catalyst carrier using a neutralizer; separating an aqueous layer from organic layer using a separator; and fractionizing the organic layer using a fractionating unit; such that, = 99.9% pure and = 99% selective tertiary-amyl benzene (TAB) is obtained.
An embodiment of the instant disclosure relates to a system to synthesize Tertiary-Amyl benzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry comprises, a vacuum dryer enabled to dry a catalyst carrier; a catalyst preparation tank enabled to prepare a catalyst slurry an ethylene storage tank enabled to store ethylene; an agitator enabled to carry out reaction between cumene and ethylene in the presence of the catalyst slurry to form a reaction mixture; a neutralizer enabled to remove residual catalyst carrier; a separator enabled to separate aqueous layer from organic layer ; and a fractionation unit enabled to fractionize the organic layer; such that, = 99.9% pure, and = 99% selective Tertiary-Amylbenzene (TAB) is obtained.
This summary is not intended to identify all the essential features of the claimed subject matter, nor is it intended to be used in determining or limiting the scope of the claimed subject matter.
BRIEF DESCRIPTION OF DRAWINGS
The detailed description of drawings is outlined with reference to the accompanying figures. In the figures, the left-most digit (s) of a reference number identifies the Figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
Fig. 1 demonstrates a process (100) for synthesizing tertiary-amyl benzene (TAB).
Fig. 2 demonstrates a system (200) to synthesize tertiary-amyl benzene (TAB); wherein, said system comprises (201) - vacuum dryer, (202) - catalyst preparation tank, (203) - agitator, (204) - neutralizer, (205) - separator, (206)- crude TAB tank, (207) - fractionizing unit, (208) - fin tube evaporator, (209) - ethylene storage tank, and (210)- cumene storage tank.
DETAILED DESCRIPTION
Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” “alternate embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment,” “in an alternate embodiment,” or “in a related embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
Before the present apparatus and process is described, it is to be understood that this disclosure is not limited to the particular apparatus and process as described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure but may still be practicable within the scope of the present disclosure.
The preferred embodiments of the present invention are described in detail above. It should be understood that ordinary technologies in the field can make many modifications and changes according to the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should fall within the protection scope determined by the claims.
Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
Also, the technical solutions offered by the present disclosure are clearly and completely described below. Examples in which specific conditions may not have been specified, have been conducted under conventional conditions or in a manner recommended by the manufacturer.
The present disclosure relates to a process (100) for synthesizing Tertiary-Amyl benzene (TAB).
A two-step process involving substitution and alkylation reaction such as Friedel-Crafts alkylation and side chain alkylation is conventionally carried out for synthesizing tertiary-amyl benzene (TAB).

Referring to Fig. 1, an exemplary embodiment of the instant disclosure relates to a process for synthesizing Tertiary-Amyl benzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry; said process comprising, drying (101) a catalyst carrier using a vacuum dryer (201); adding (102) a catalyst to the dried catalyst carrier to form a mixture; preparing (103) a catalytic composition in a catalyst preparation tank (202) using the mixture; charging (104) the catalyst slurry, cumene obtained from a cumene storage tank (210), and the gasified ethylene to the agitator (203) to form a reaction mixture; neutralizing (105) the reaction mixture to remove residual catalyst carrier using a neutralizer (204); separating (106) aqueous layer from organic layer using a separator (205); and fractionizing (107) the organic layer using a fractionizing unit (207); such that, = 99.9% pure and = 99% selective Tertiary Amyl benzene (TAB) is obtained.
Referring to Fig. 2, of the instant disclosure, yet another exemplary embodiment of the instant disclosure relates to a system (200) to synthesize Tertiary-Amyl benzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry; comprises, a vacuum dryer (201) enabled to dry a catalyst carrier; a catalyst preparation tank (202) enabled to prepare a catalytic composition; an ethylene storage tank (209) enabled to store liquified ethylene; an agitator (203) enabled to carry out reaction between cumene and ethylene in the presence of the catalyst slurry to form a reaction mixture; a neutralizer (204) enabled to remove residual catalyst carrier; a separator (205) enabled to separate aqueous layer from organic layer; and a fractionation unit (207). In one embodiment, wherein the system further comprises a fin tube evaporator (208) enabled for gasification of liquified ethylene. The fractionation unit (207) enabled to fractionize the organic layer for efficient recovery of TAB from other side products; such that, = 99.9% pure, and = 99% selective Tertiary-Amyl benzene (TAB) is obtained.

In one embodiment, the synthesis of tertiary-amyl benzene (TAB) is carried out by alkylating cumene; and preferably, by alkylating cumene with ethylene.

In another embodiment, the synthesis of tertiary-amyl benzene (TAB) is carried out in the presence of a catalyst selected from at least one of K, sodium (Na), Na/K, KOH, sodium carbonate, or ? –Al2O3; and preferably, sodium catalyst.

In a related embodiment, the synthesis of tertiary-amyl benzene (TAB) is carried out in the presence of a catalyst carrier selected from at least one of silica, alumina, potassium carbonate, or zirconia; and preferably, potassium carbonate.

The instant disclosure of the process (100) further relates to drying (101) a catalyst carrier to remove any moisture present. For the purpose of this disclosure, at least one of conventionally known drying methods such as sun drying, freeze drying, contact drying, vacuum dryer, dielectric drying, infrared drying is implemented for drying a catalyst carrier; particularly, a vacuum dryer.

In one embodiment a step of adding (102) a catalyst to the dried catalyst carrier to form a coted mixture; preferably, in a specific ratio. In a related embodiment, the ratio of catalyst to the catalyst carrier ranges from 1:1 to 1:15; and preferably, from 1:5 to 1:10.

Yet another related embodiment relates to activating the catalyst composition; preferably, at a temperature ranging from 100°C - 250°C; and particularly from 150°C - 200°C.

Another embodiment of the instant disclosure relates to preparing (103) a catalytic composition in a catalyst preparation tank using the mixture. For the purpose of this disclosure, the catalyst preparation tank is at least one of rectangular flask, conical flask, or round bottom flask.

In a related embodiment, the catalytic composition further comprises a fatty acid acting as an emulsifier or a surfactant for consistent reaction of cumene and ethylene in presence of the catalyst composition in accordance with the disclosure.
For the purpose of this disclosure, the fatty acid is selected from at least one of palmitic acid, and oleic acid, or mixtures thereof; and preferably, oleic acid.

An embodiment relates to a step of charging (104) reactants such cumene to the catalytic composition to form a catalyst slurry to the agitator (203); preferably, in a specific ratio. For the purpose of this disclosure, the ratio of cumene to the catalytic composition ranges from 5 to 35:1; and preferably, from 15 to 30:1.

In another embodiment, wherein a step of charging and adding (104) reactants relates to charging the catalyst slurry, and cumene to an agitator (203); preferably, a gas induction agitator. In the present disclosure, the agitator (203) is enabled to carry out reaction between cumene and ethylene in the presence of the catalyst slurry to form a reaction mixture. In a further embodiment, the agitator comprises of a hollow shaft impeller; preferably, having perforated holes. In yet another further embodiment, the agitator (203) comprises gas injecting inlets. Further the step of a step of charging (104) reactants comprises a sub-step of injecting ethylene from an ethylene storage tank to the agitator (203) to form a reaction mixture.

In a related embodiment, the liquid ethylene is gasified; preferably using at least one of conventionally known methods selected from film evaporator, recovery boiler and fin tube evaporator; and particularly using a fin tube evaporator. In yet another related embodiment, ethylene is injected to the agitator (203) from bottom of the hollow shaft impeller; preferably having perforated holes against pressure ranging from 15 to 30 Kg/cm2.

The instant disclosure of the process (100) further relates to a step of neutralizing (105) the reaction mixture for removal of residual catalyst carrier from the reaction mixture via a neutralizer (204).

In a related embodiment, the step of neutralization (105) is carried out using a calorimeter. In yet another related embodiment, a neutralizer (204) is enabled to remove residual catalyst carrier. For the purpose of this disclosure, the neutralizer (204) is a layer separator, downflow, or an up-flow neutralizer; and preferably the layer separator neutralizer (204). In an exemplary embodiment, the neutralizer flares spent gas. For the purpose of this disclosure, the spent gas is ethylene.

During the step of neutralization (105), water is added to obtain an aqueous and organic layer. In an embodiment, the aqueous layer obtained due to addition of water in the neutralization stage is separated from the organic layer and also enabling removal of residual catalyst carrier from the reaction mixture organic layer using at least one of fundamentally known separating methods selected from centrifugation, layer separation, fractionation and extraction.

In a further embodiment, the process (100) wherein the organic layer is fractionized (107) to obtain pure tertiary-amyl benzene (TAB); preferably via a fractionization unit (207).

In one embodiment, tertiary-amyl benzene (TAB) obtained is pure; preferably, = 99.9% pure. In another embodiment, tertiary-Amyl benzene (TAB) obtained is selective; preferably, = 99% selective.
The features and properties of the present disclosure are described in further detail below with reference to examples.

Example 1: Catalyst carrier screening for synthesizing Tertiary-Amyl Benzene (TAB)
The Example 1 of the present disclosure refers to a process step of screening of catalyst carrier in the production of tertiary amyl benzene (TAB) the process incorporates the following steps: The steps involve independently drying the catalyst carriers such as diatoms powder, ? alumina and potassium carbonate by using a vacuum dryer. Then a catalyst such as Sodium catalyst was added to the independently dried catalyst carriers to form mixtures. The effect of incorporating different catalyst carriers is described in Table 1 and 2 below.
Table 1: Use of diatoms powder as a catalyst carrier at constant reaction temperature.
Components 1 2 3 4
Cumene (Plant-99.87%) – g 800 800 800 800
Ethylene (Vapour Phase) - g 106 110 105 105
Diatoms powder 50 50 50 50
Sodium – g 6 5 5 5
Oleic acid - mL 5 4 4 4
Reaction Temp. 220 220 220 220
Reaction Pressure Max. 30 30 30 30
Pressure before quenching 28.9 29 30 28.5
Reaction time hrs 6 6 6 6
TAB No Conversion

Table 2: Use of ? alumina powder as a catalyst carrier at constant reaction temperature.
Components 1 2 3 4
Cumene (Plant-99.87%) – g 800 800 800 800
Ethylene (Vapour Phase) - g 98 103 86 91
? alumina powder 30 30 50 50
Sodium – g 6 5 5 5
Oleic acid - mL 5 5 5 5
Reaction Temp. 220 220 220 220
Reaction Pressure Max. 26 28 24 25
Pressure before quenching 25.3 27.4 23.5 24.3
Reaction time hrs 6 6 6 6
TAB No Conversion

Example 2
Table 3: Use of K2CO3 powder as a catalyst carrier at constant reaction temperature
Initially, 50 g of potassium carbonate was dried using a vacuum dryer. Then about 4 - 6 g of sodium catalyst was added to the dried potassium carbonate to form a mixture. The mixture was added to a catalyst preparation tank and heated at a temperature of about 220°C for about 6 hours to form a catalytic composition. Then, about 500-800 g of cumene was added to the catalytic composition and reacted at a temperature of about 220°C for about 6 hours to form a catalyst slurry. Alternatively, about 3 - 4 ml of fatty acid-based emulsifier or as a dispersing agent such as oleic acid was further added to the catalytic composition to form the catalyst slurry. The catalyst slurry obtained as a result was either stored or implemented for synthesizing for synthesizing tertiary-amylbenzene (TAB) in presence of cumene and vapour phase ethylene gas.
Particulars # 1 # 2 #3 # 4 #5
Cumene (plant-99.87%) - g 500 500 500 500 550
Ethylene (Vapour Phase) - g 157 157 155 145 100
Cumene: C2 ratio 1: 1.35 1: 1.35 1: 1.33 1: 1.24 1: 0.78
K2CO3 - g 50 50 35 50 50
Sodium - g 5 6 3.5 5 5
Oleic acid - mL 5 5 4 5 3
Reaction Temp. 180 180.8 179.7 180.3 177.5
Reaction Pressure Max. 25 24 25 24 33
Pressure before quenching 8 9 7 9 9
Reaction time hrs 8 6 6 6 8
Batch Analysis (GC)
Ethylene 0.7237 0.0043 0 0.044 0
Lighter 0.016 0.01 0.08 0.05 0.01
Cumene 0.83 1.40 1.98 2.94 33.21
Cumene + 0.002 0.006 0.100 0.002 0.002
TAB - 0.01 0.00 0.04 0.004 0.04
TAB (purity) 97.73 97.72 96.45 95.95 57.68
TAB + 0.006 0.033 0.050 0.112 6.77
Heavies 0.55 0.09 0.56 0.73 1.7
% Selectivity of TAB 99.99 99.97 99.95 99.88 89.50
% Selectivity of TAB+ 0.01 0.03 0.05 0.12 10.50

As per Table 1, 2 and 3, Use of diatoms powder as well as ? alumina as a catalyst resulted in to no conversion of TAB. However, implementation of potassium carbonate as the catalyst carrier gave higher yield, reaction selectivity, and purity.

Example 3
Process for synthesizing Tertiary-Amyl Benzene (TAB)
25 g of catalyst slurry prepared in the Example 2 Table 3 and about 3500 g of cumene was charged to an agitator. Then, about 375g g of ethylene gas was injected to the said agitator. The mixture obtained as a result was reacted at a temperature of about 163°C - 166°C for about 6 hrs. to form a reaction mass. The reaction mass was then charged to a neutralizer. In the neutralizer, water was added for neutralizing the reaction mass i.e., to dissolve the catalyst carrier (e.g., potassium carbonate) and to vent excess ethylene gas. The neutralized mixture obtained as a result was then charged to a separator that enabled the separation of aqueous layer from organic layer. The organic layer separated as a result was transferred to a crude tank for further fractionization. The excess cumene present in the organic layer was recovered in the cumene column. TAB was further purified and collected in an intermediate tank. The purified tertiary-amyl benzene TAB obtained as a result was analyzed for its purity, yield, and selectivity (see Table 4).

Table 4: Content of reaction components and yield of TAB obtained
Components 1 2 3 4
Cumene 3500 3500 2500 2500
Ethylene 375 175 150 100
K2CO3 250 175 150 100
Sodium 25 17 12 10
Oleic acid 2 1 2 1
NaOH 5 10 12 2
Reaction Temp. 163~166 120~154 120~154 163~166
Reaction pressure Max. 16 16 21.8 23.7
Delta P 5.5 10 10 18.7
Off Gas 50 42 75.6 35
% ethylene in residual vent gas 15.6 12.2 0 11.5
TAB (% yield) 35.04 30.91 0.27 28.12
Heavies 0.31 0.32 0.00 0.04

As per Table 4 highest yield of TAB i.e., 35.04 % was obtained when 3500g of cumene, 375 g of ethylene, 250 g of catalyst carrier K2CO3, 25g of sodium catalyst, 2 g of oleic acid, 5 g of sodium hydroxide were reacted at a reaction temperature of 163-166°C and reaction pressure of 16 N/m2.
Further, it was concluded that the instant process achieves = 99.9% purity and = 99% selectivity of Tertiary-Amyl Benzene (TAB).
The foregoing description shall be interpreted as illustrative and not in any limiting sense. A person of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure.
, Claims:WE CLAIM:
1. A process for synthesizing Tertiary-Amyl benzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry; said process comprising:
drying (101) a catalyst carrier using a vacuum dryer (201) and
adding (102) a catalyst to the dried catalyst carrier to form a mixture;
preparing (103) a catalytic slurry composition in a catalyst preparation tank (202) using the dried catalyst carrier and a catalyst;
Charging (104) the catalytic slurry, cumene, and a gasified ethylene to the agitator (203) to form a reaction mixture;
neutralizing (105) the reaction mixture to remove residual catalyst carrier using a neutralizer (204);
separating (106) an aqueous layer from an organic layer using a separator (205); and
fractionizing (107) the organic layer using a fractionizing unit (207);
such that, = 99.9% pure and = 99% selective Tertiary Amyl benzene (TAB) is obtained.

2. The process as claimed in claim 1, wherein the gasified ethylene is obtained by ethylene gasification carried out using a fin tube evaporator, wherein ethylene is injected in the reactor against a pressure ranging from 15 to 30 Kg/cm2.

3. The process as claimed in claim 1, wherein the catalyst is sodium catalyst and, the dried catalyst carrier is potassium carbonate.

4. The process as claimed in claim 1, wherein a ratio of the catalyst to the catalyst carrier ranges from 1:5 to 1:10.

5. The process as claimed in claim 1, wherein a ratio of cumene to the catalytic slurry ranges from 5 to 35:1.

6. The process as claimed in claim 1, wherein the catalytic composition further comprises on or more fatty acids as emulsifiers selected from at least one of oleic acid, palmitic acid, or mixtures thereof.

7. The process as claimed in claim 1, wherein the catalyst is activated at a temperature ranging from 150°C to 200°C.

8. A system (200) to synthesize Tertiary-Amylbenzene (TAB) by alkylating cumene with ethylene in the presence of a catalyst slurry; comprises:
a vacuum dryer (201) enabled to dry a catalyst carrier;
a catalyst preparation tank (202) enabled to prepare a catalytic composition;
an ethylene storage tank (209) enabled to store ethylene;
an agitator (203) enabled to carry out reaction between cumene and ethylene in the presence of the catalyst slurry to form a reaction mixture;
a neutralizer (204) enabled to remove residual catalyst carrier and flare spent ethylene gas;
a separator (205) enabled to separate aqueous layer from organic layer; and
a fractionation unit (207) enabled to fractionize the organic layer;
such that, = 99.9% pure, and = 99% selective tertiary-amyl benzene (TAB) is obtained.

9. The system (200) as claimed in claimed in claim 8, wherein the system further comprises a fin tube evaporator (208) enabled for gasification of liquified ethylene.

10. The system (200) as claimed in claim 8, wherein the agitator (203) is a gas induction agitator comprising the agitator comprises hollow shaft impeller having perforated holes, and one or more gas injecting inlets.

Dated this 01st Day of September 2023

Deepak Pawar
Agent for the Applicant
IN/PA-2052