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 METHOD AND SYSTEM FOR CONVERSION OF AN AROMATIC ALKYL HYDROPEROXIDE TO AN AROMATIC ALKYL KETONE

APPLICANT:
Deepak Phenolics Limited
An Indian entity having address as,
Register & Corporate Office, 4th Floor, Fermenter House, Alembic City, Alembic Avenue Road, Vadodara – 390003, Gujarat, 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 described herein, in general, relates to a field of organic decomposition reactions, and more particularly relates to a continuous system and a continuous method for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone.

BACKGROUND
Aromatic alkyl hydroperoxides are organic compounds characterized by a hydroperoxide group (-OOH) attached to an alkyl attached to aromatic ring. These compounds are important intermediates in organic synthesis and are often used as oxidizing agents in chemical reactions. Their unique structure combines the reactivity of the hydroperoxide group with the stability and electronic properties of the aromatic ring, making them versatile in various applications. Aromatic alkyl hydroperoxides also play significant role in industrial processes, including polymerization initiator and the production of commodity, fine and speciality chemicals. However, due to their high oxygen content/high energetic nature, it must be handled with care as they can pose risks of decomposition, thermal runaway and combustion under certain conditions.
The decomposition of aromatic alkyl hydroperoxides is a significant process influenced by temperature, catalysts, and the surrounding environment. Upon decomposition, they often yield phenolic compounds, aromatic alkyl ketones, or aromatic alkyl alcohols / alkyl alcohols, hydrocarbons, alongside the release of reactive oxygen species/oxy radicals. This process can be highly exothermic, posing risks of thermal runaway or explosion if not properly managed. The material should be kept below the temperature of TD24 to mitigate the self-decomposition or accelerated decomposition.
By decomposing aromatic alkyl hydroperoxide in a reaction medium containing water, a water-soluble cupric salt as catalyst, and either an aromatic hydrocarbon or an aromatic alkyl alcohol solvent, yielding ketone and other byproducts like phenol and hydrocarbons.
In the state of art, US application no. US3968162 discloses process for producing an aromatic alkyl ketone. However, the process faces several challenges while transforming into a full industrial scale process. It uses a simpler catalyst system with a water-soluble cupric salt and lacks the detailed control over reaction conditions and operating conditions, such as precise flow rates and residence times, which can lead to lower reaction efficiency and product selectivity. The broader temperature range and molar ratio variations may result in less optimized reaction kinetics, potentially causing slower or incomplete reactions and affecting the overall conversion rate to desired products. This can lead to lower product yield and purity. Additionally, the process lacks a well-defined product separation and distillation steps, which could affect the recovery and purity of aromatic alkyl ketones and other byproducts, resulting in less effective separation and lower-quality products. Also, aromatic alkyl hydroperoxide is highly reactive, and its decomposition must be carefully controlled to avoid hazardous thermal runaway reactions.
In the state of art, Japanese patent application JPS5931729A discloses that the acetophenone is recovered from heavier fraction of crude phenol process. Acetophenone from a phenol process is available only in the form of low purity product, generally up to maximum 20%, and is part of the plant waste heavies stream with good calorific value. Separation of the acetophenone and subsequent purification is extremely difficult due to the close proximity of its boiling point to azeotropes of other materials contained in the phenol heavies. Because of above challenges, conventional distillation cannot be used to yield high purity acetophenone.
In the state of art, US patent no. US4559110A discloses an improved method of separating acetophenone from a mixture thereof which contains phenol and phenolic heavies.
Moreover, maintaining such elevated temperatures accelerates equipment wear, often necessitating the use of more expensive, heat/corrosion-resistant materials, promote side reactions, potentially forming unwanted byproducts that must be removed which results into driving up capital costs. Operating under above high pressure adds additional process complexity, as it raises safety concerns related to leaks, equipment failure, and the need for more robust safety protocols, increasing both operational costs and the risk of accidents.
In addition to the challenges posed by temperature and pressure, the process involves the creation and separation of an azeotrope, which can be difficult due to the specific composition and boiling points of the phenols-aromatic ketone mixture. This often requires additional distillation steps or specialized separation techniques, reducing process efficiency. Additionally, the high operational temperatures and pressures contribute to frequent equipment maintenance needs, increasing downtime and repair costs.
Further, batch process used in the conventional method for producing aromatic alkyl ketone has several disadvantages. It is often less efficient compared to continuous processes, as it involves periodic shutdowns for loading and unloading materials, leading to lower overall throughput efficiency. Additionally, batch processes are prone to variations in product quality due to inconsistencies in reaction conditions, such as temperature, pressure, and reaction time. This can require additional purification steps, increasing operational costs. Moreover, the need for frequent cleaning and setup between batches can result in longer downtime, further reducing productivity and increasing maintenance costs.
Above batch process is associated with the process hazard since the concentration of aromatic alkyl hydroperoxide is high after complete addition of aromatic alkyl hydroperoxide in the reaction system. Hence, there is utmost need to make a safer process by reducing the hazards associated with concentration of aromatic alkyl hydroperoxide in the process.
The increasing demand for aromatic alkyl ketone specifically such as a key intermediate in the production of pharmaceuticals, fragrances, speciality chemicals and polymers has driven advancements in selective production methods that maximize yield while minimizing by-products like phenol, alkyl aromatic, alkene aromatic, aromatic alkyl alcohol, and the like. Traditional methods often suffer from low selectivity, resulting in significant amounts of phenol as a by-product, which adds to waste disposal challenges and reduces overall process efficiency. These selective production techniques are designed to enhance the conversion of starting materials into aromatic alkyl ketone (e.g., acetophenone) while minimizing side reactions, aligning with the growing demand for more sustainable and efficient manufacturing processes. The future of aromatic alkyl ketone (e.g., acetophenone) production lies in refining these methods to further improve product yield, reduce environmental impact, and meet the increasing industrial and commercial needs for this valuable chemical.

Therefore, there has always been a long-standing need to develop a high throughput, cost-effective, and economically feasible system and method for selective conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone with high purity product that reduces the production of byproducts and maximizes the yield of product.

SUMMARY
Before the present system and its components are described, it is to be understood that this disclosure is not limited to the particular system and its arrangement as described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope of the present application. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in detecting or limiting the scope of the claimed subject matter.
As disclosed herein, the present subject matter relates to a method for conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone and a system for conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone.
In one implementation, a method for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone is disclosed. The method may comprise mixing a catalyst solution with mineral acid and water to obtain a premix. The method may comprise reacting the aromatic alkyl hydroperoxide and the premix into a first reactor to obtain a reaction mass A. The method may comprise transferring an overflow of the reaction mass A from the first reactor to a second reactor via a fluid overflow management system to obtain a reaction mass B. The method may comprise separating the reaction mass B in a layer separation unit to obtain an aqueous layer and a first organic fraction. The first organic fraction comprises an alkyl aromatic, an aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone. Further, the method may comprise distilling the first organic fraction in a first distillation unit to separate the alkyl aromatic and to obtain a second organic fraction comprising the aromatic alkyl alcohol, and the aromatic alkyl ketone. The method may comprise of dehydrating the second organic fraction comprising the aromatic alkyl alcohol in a fluidized or fixed bed reactor to obtain a third organic fraction comprising an alkenyl aromatic compound, and the aromatic alkyl ketone. Additionally, the method may comprise distilling the third organic fraction via a second distillation unit to obtain a refined aromatic alkyl ketone.
In another implementation, a system for conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone is disclosed. The system may comprise a first reactor, for reacting an aromatic alkyl hydroperoxide and the premix comprising of the catalyst solution, water, and mineral acids to obtain a reaction mass A. The system may comprise a fluid overflow management system, for transferring an overflow of reaction mass A from the first reactor to a second reactor. The system may comprise a second reactor, for receiving overflow of reaction mass A from the first reactor to obtain a reaction mass B. The first reactor and the second reactor comprise of at least one stirring apparatus. The system may comprise a layer separation unit, for separating the reaction mass B into a first organic fraction and an aqueous layer, wherein the first organic fraction comprising an alkyl aromatic, aromatic alkyl alcohol, phenol and the aromatic alkyl ketone. The system may comprise a first distillation unit, for separating the alkyl aromatic from the first organic fraction and to obtain a second organic fraction comprising the aromatic alkyl alcohol and the aromatic alkyl ketone. Further, the system may comprise a fluidized or fixed bed reactor, for dehydrating the aromatic alkyl alcohol from the second organic fraction into an alkenyl aromatic compound forming a third organic fraction comprising the alkenyl aromatic compound, and the aromatic alkyl ketone. Furthermore, the system may comprise a second distillation unit, for distillation of the third organic fraction to obtain a refined aromatic alkyl ketone.

List of Abbreviations
CHP - Cumene hydroperoxide
DMBA – Alpha, Alpha’-dimethyl benzyl alcohol
AMS – Alpha methyl styrene
CSTR – Continuous stirred tank reactor

BRIEF DESCRIPTION OF FIGURES
The detailed description is described with reference to the accompanying Figures. In the Figures, the left-most digit(s) of a reference number identify the Figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 1 depicts (100) the method steps for continuous conversion of an aromatic alkyl hydroperoxides to an aromatic alkyl ketone.

Figure 2 depicts (200) the continuous system for conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone.

Figure 3 depicts (300) continuous reactor assembly comprising a first reactor and a second reactor.
DETAILED DESCRIPTION
Reference throughout the specification to “various embodiments,” “some embodiments,” “one 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 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.
The words “comprising”, “having”, “containing”, and “including”, and other forms thereof are intended to be equivalent in meaning and be open-ended in that an item or items following any one of these words is not meant to be exhaustive listing of such item or items or meant to be limited to only the listed item or items. It must also be noted that the singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Although any methods similar or equivalent to those described herein may be used in the practice or testing of embodiments of the present disclosure, the exemplary methods are described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
Various modifications to the embodiment may be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, a skilled person in the art may 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. A detailed description of the invention will be described hereinafter.
The present disclosure relates to a continuous method and a system for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone. The method overcomes the major drawbacks commonly associated with conventional processes. Traditional methods often face challenges such as incomplete reactions, inefficient separation of by-products, and excessive energy consumption due to multiple complex steps. The present innovative method ensures a higher conversion rate through a two-reactor system with optimized reaction control, efficient phase separation, and sequential distillation steps. By incorporating a fluidized bed reactor, or a fixed bed reactor for targeted dehydration and precise management of by-product removal, the process minimizes waste and enhances product purity. The disclosed system integrates these components seamlessly, reducing operational inefficiencies, improving safety, and enabling scalability for industrial applications.
In an embodiment, the aromatic alkyl ketone obtained from the disclosed process is any one of:
, , OR
wherein R1 is a methyl group or a (C1-C3)-alkyl group, R2 or R3 = hydrogen, (C1-C3)-alkyl group, methyl, ethyl, isopropyl, tert-butyl, -cycloalkyl, -NO2, -CF3, -CN, -OCH3, -CHO, -COOH, -COCH3, -CONH2, and halogens.
In an embodiment of the present disclosure, referring to figure 1, a method for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone is disclosed. The method begins with the preparation of the premix comprising the catalyst solution, water, and mineral acid followed by reaction of the premix with the aromatic alkyl hydroperoxide in a first reactor, achieving partial conversion. The reaction mass is then transferred via a fluid overflow management system to a second reactor for further reaction completion.

The resulting mixture undergoes phase separation in a layer separation unit to isolate an aqueous layer and an organic fraction containing the desired products and by-products. The organic fraction is subjected to sequential distillation to separate alkyl aromatic and further refined to obtain a second organic fraction rich in aromatic alkyl alcohol and the target aromatic alkyl ketone. The fluidized bed reactor, or the fixed bed reactor is employed for dehydrating the second organic fraction to produce an alkenyl aromatic compound and the ketone, which is further purified through a final distillation step.

In an embodiment, referring to figure 1, the method (100) may comprise a step of mixing (102) a catalyst solution to obtain the premix. The premix comprises of the catalyst solution of one or more hydrated metal sulphates in presence of water, and mineral acids such as H₂SO₄, HCl, HClO4, HNO3, and organic sulphonic acids. The catalyst solution is formulated using one or more hydrated metal sulphates, selected from copper (II) sulphate pentahydrate (CuSO₄·5H₂O), zinc sulphate heptahydrate (ZnSO₄·7H₂O), cobalt (II) sulphate heptahydrate (CoSO₄·7H₂O), magnesium sulfate heptahydrate (MgSO₄·7H₂O), iron (II) sulphate heptahydrate (FeSO₄·7H₂O), and the like. Preferably the one or more hydrated metal sulphates are copper (II) sulphate pentahydrate (CuSO₄·5H₂O) and iron (II) sulphate heptahydrate (FeSO₄·7H₂O).

The redox potential of metal ions plays a crucial role in determining the selectivity and efficiency of catalytic reactions, particularly in the formation of ketones and alcohols. Metals like copper and iron, with specific oxidation-reduction properties, facilitate electron transfer between reactants, enabling selective cleavage of hydroperoxides to form ketones. A well-optimized redox potential favours the desired reaction pathway, promoting ketone formation while minimizing side reactions that lead to alcohols. By controlling the redox conditions, such as adjusting the metal ion concentration and pH, the process can be fine-tuned to enhance selectivity, thereby improving yield and reducing the formation of undesired byproducts like alcohols, aromatic hydrocarbons, traces of phenolic compounds, alkene aromatics, and the like.

In a related embodiment, the premix comprises of one or more hydrated metal sulphates, and at least one mineral acid i.e., in a ratio ranging between 0.5:0.5:1 to 3:3:1. Preferably, the ratio is in the range of 1:1:2 to 2:2:1.
The Fe²⁺, Cu²⁺ and mineral acid such as sulfuric acid (H₂SO₄) combination, is selected in a molar ratio of 0.5:0.5:1 to 3:3:1, and preferably 2:1:1 with a substrate or other components, offering an optimized balance for enhanced conversion and selectivity in the reaction. Fe²⁺ serves as a potent redox-active species, facilitating electron transfer, while Cu²⁺ complements its activity by stabilizing reaction intermediates and enabling efficient coordination, and robust catalytic cycles. The synergistic interaction between these two metal ions and mineral acid ensures precise control over reaction pathways, minimizing side reactions and improving the yield of the desired product.

In an embodiment, the step of mixing of catalyst solution comprising copper (II) sulphate pentahydrate (CuSO₄·5H₂O) and iron (II) sulphate heptahydrate (FeSO₄·7H₂O) combined with sulfuric acid (H₂SO₄) and water is carried out to form the premix. The hydrated metal sulphates act as effective catalytic agents, enhancing the reaction efficiency by promoting the breakdown of the aromatic alkyl hydroperoxide. The presence of sulfuric acid not only stabilizes the catalyst system but also optimizes the reaction environment by providing the necessary acidity. Water ensures uniform dispersion of the components, enabling the formation of a homogeneous premix. This premix is essential for ensuring consistent catalytic activity, leading to high reaction rates and better control over product selectivity and yield in the subsequent reaction steps.
In an embodiment, the pH of the premix is acidic. The pH of the premix is in the range of 1-5. Preferably, pH is in the range of 1-3. The acidic pH of the premix ensures a highly acidic environment conducive to the reaction. This acidity is essential for promoting the decomposition of the aromatic alkyl hydroperoxide and enhancing the catalytic efficiency of the hydrated metal sulphates present in the solution.
Preferably, the pH is within the range of 1-3, providing even stronger acidity, which is ideal for maximizing the reactivity of the catalyst and achieving a higher conversion rate. Such acidic conditions ensure the proper functioning of the catalyst while minimizing side reactions and by-product formation, leading to a more efficient and selective process.

In an embodiment, the method (100) comprises a step of reacting (104) the aromatic alkyl hydroperoxide and the premix into a first reactor (206) to obtain a reaction mass A.
In an embodiment, the substrate such as aromatic alkyl hydroperoxide may be selected from
, , or
wherein R1 is a methyl group or a (C1-C3)-alkyl group, R2 or R3 = hydrogen, (C1-C3)-alkyl group, methyl, ethyl, isopropyl, tert-butyl, -cycloalkyl, -NO2, -CF3, -CN, -OCH3, -CHO, -COOH, -COCH3, -CONH2, and halogens.
Preferably, the aromatic alkyl hydroperoxide as a starting material is selected from at least one of methyl phenyl hydroperoxide, p-tert-butyl cumene hydroperoxide, 1-methyl-1-phenylpropyl hydroperoxide, 1-methyl-1-naphthyl ethyl hydroperoxide, 1-methyl-1-biphenyl ethyl hydroperoxide, cumene hydroperoxide (CHP), and the like. Preferably, the aromatic alkyl hydroperoxide is cumene hydroperoxide (CHP).

The aromatic alkyl hydroperoxide is in form of a solution. The solution may comprise one or more solvents or diluents such as but not limited to alkylated benzenes (di-, tri-, tetra-), toluene, xylene, cumene, methyl iso-butyl ketone (MIBK), dimethyl benzyl alcohol (DMBA), and alpha-methyl styrene (AMS).

During this step, the aromatic alkyl hydroperoxide undergoes a catalytic decomposition reaction, facilitated by the presence of the premix comprising catalyst solution, which typically consists of one or more hydrated metal sulphates in an acidic medium.

The highly acidic environment within the reactor promotes the breakdown of the hydroperoxide, leading to the formation of intermediate products, such as aromatic alkyl alcohol and the desired aromatic alkyl ketone. The reaction mass A, which results from this process, contains a mixture of the desired aromatic alkyl ketone, unreacted hydroperoxide, and other by-products. This step initiates the reaction achieving a substantial portion of the desired conversion before transferring the reaction mass to the next stage of processing.

In a related embodiment, a residence time of the aromatic alkyl hydroperoxide in the first reactor (206) ranges from 0-2 hours. Preferably, the residence time of the aromatic alkyl hydroperoxide in the first reactor (206) ranges from 0.5-1.5 hours.

The residence time is maintained to allow enough time for the aromatic alkyl hydroperoxide to undergo decomposition under the influence of the premix. Preferably, the residence time is optimized to 0.5-1.5 hours, which strikes a balance between maximizing reaction efficiency and preventing overreaction or the formation of unwanted by-products. This specific time range ensures that the aromatic alkyl hydroperoxide is exposed to the catalytic conditions long enough to achieve significant conversion, while also preventing the buildup of excessive heat or pressure that could negatively impact product quality or process safety. The controlled residence time enhances the consistency and scalability of the process, making it suitable for industrial applications.

In another related embodiment, the step of reacting (104) the aromatic alkyl hydroperoxide and the premix into a first reactor (206) to obtain a reaction mass A is carried out at a temperature ranging between 50-100°C. Preferably, at a temperature ranging between 55-95°C. This temperature range ensures sufficient activation of the catalyst while minimizing the risk of side reactions or degradation of the desired aromatic alkyl ketone, thus enhancing the overall efficiency and selectivity of the process.

In an embodiment, a step of transferring (106) an overflow of the reaction mass A from the first reactor (206) to a second reactor (208) via a fluid overflow management system (310) is carried out to obtain a reaction mass B.
Alternatively, the second reactor (208) may comprise a series of one or more continuous stirred tank reactors.

As the reaction progresses in the first reactor (206), the conversion of aromatic alkyl hydroperoxide into the desired aromatic alkyl ketone leads to the formation of reaction mass A, which contains both reacted and unreacted components. The overflow management system (306) facilitates the seamless transfer of this mixture into the second reactor (208) for further processing and to obtain reaction mass B. This transfer process is essential for maintaining efficient reaction conditions in both reactors, ensuring that the remaining reaction can occur under controlled conditions in the second reactor (208). The fluid overflow system (310) also helps to manage heat and pressure balance, preventing system overload and ensuring smooth, efficient, and faster operation.

In a related embodiment, the step of reacting (104) the aromatic alkyl hydroperoxide and the premix in the first reactor (206) is carried out to obtain reaction mass A for completion of 85-99% of the reaction, and the step of transferring (106) the reaction mass A to the second reactor is carried out for the completion of rest 1-15% of the reaction. Preferably, the step of reacting (104) the aromatic alkyl hydroperoxide and the premix is carried out in the first reactor (206) for the completion of 95-99% of the reaction and the step of transferring (106) the reaction mass A to the second reactor is carried out for the completion of rest 1-5% of the reaction obtaining a reaction mass B.
This stepwise continuous reaction approach allows for better control over the reaction process, optimizing both the reaction kinetics and the quality of the final product. By conducting the majority of the reaction in the first reactor, and rest of the reaction in one or more subsequent reactors, the method (100) ensures that the initial stages, where the bulk of the conversion occurs, are carried out under optimal conditions for efficiency and selectivity. The one or more subsequent reactors may be a second reactor, or a second reactor setup comprises a series of one or more continuous stirred tank reactors. The transfer of the reaction mass A to the second reactor (208) allows for the completion of the reaction under more controlled conditions, minimizing the potential for overreaction, side products, and energy waste.
In an embodiment, a step of separating (108) the reaction mass B in a layer separation unit (210) is carried out to obtain an aqueous layer and a first organic fraction, wherein the first organic fraction comprises an alkyl aromatic, an aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone. The aqueous layer typically contains water-soluble by-products, such as excess sulfuric acid or water-soluble impurities, while the first organic fraction contains the desired organic compounds. This organic fraction comprises the alkyl aromatic, the aromatic alkyl alcohol, phenol, and the desired aromatic alkyl ketone. The separation step is essential for isolating the valuable organic phase from the aqueous phase, enabling efficient recovery of the aromatic alkyl ketone and the alkyl aromatic for possible reuse in subsequent reactions.

The presence of the aromatic alkyl alcohol in the first organic fraction is an intermediate by-product, which can be further processed in subsequent stages to enhance product purity. This separation step is key for reducing contamination and optimizing the yield of the final aromatic alkyl ketone product, while also ensuring that unreacted reactants and by-products can be effectively managed or recycled.

In a related embodiment, the step of separating (108) the reaction mass B into an aqueous layer and the first organic fraction is carried out at a temperature ranging from 10-50°C. Preferably, at a temperature ranging from 15-45°C.

In an embodiment, a step of washing (109) the first organic fraction in the washing unit (206) is carried out to remove the acidity and residual metal content before first distillation. This washing step (109) is carried out for neutralizing the first organic fraction, effectively reducing any remaining acid, such as sulfuric acid, which could otherwise interfere with subsequent distillation or degrade the product.

Additionally, any trace metal residues, including catalytic components like hydrated metal sulphates, are removed, preventing potential contamination of the aromatic alkyl ketone and ensuring higher purity of the final product. This prepares the first organic fraction for efficient separation of alkyl aromatic and aromatic alkyl ketone during distillation, contributing to both product quality and process safety.

In a related embodiment, the first organic fraction comprises the alkyl aromatic in the range of 50-70%, the aromatic alkyl ketone in the range of 20-40%, minute traces of phenol in ppm, and the aromatic alkyl alcohol in the range of 2-8%. Preferably, the first organic fraction comprises the alkyl aromatic in the range of 45-65%, the aromatic alkyl alcohol in the range of 2-6%, minute traces of phenol in ppm, and the aromatic alkyl ketone in the range of 25-35%.

In an embodiment, a step of distilling (110) the first organic fraction in a first distillation unit (214) is carried out to separate the unreacted alkyl aromatic and to obtain a second organic fraction comprising the aromatic alkyl alcohol, and the aromatic alkyl ketone. This method step ensures efficient separation for potential recycling or reuse of the alkyl aromatic. This step of distilling (110) yields a second organic fraction enriched with the aromatic alkyl alcohol and the aromatic alkyl ketone, which are key intermediates or final products in various industrial applications. This step optimizes the purification process by effectively separating components based on their boiling points, enhancing overall process efficiency and product quality.

In a related embodiment, a step of distilling (110) the first organic fraction in the first distillation unit (214) is carried out to separate the alkyl aromatic and to obtain a second organic fraction at a temperature ranging between 50-120°C. Preferably, the step of distilling (110) the first organic fraction in the first distillation unit (214) is carried out at a temperature ranging between 60-110°C under vacuum.

In an embodiment, a step of dehydrating (112) the second organic fraction comprising the aromatic alkyl alcohol in the fluidized or the fixed bed reactor (216) is carried out to obtain a third organic fraction comprising an alkenyl aromatic compound and oligomeric isomers of alkenyl aromatic compound, and the aromatic alkyl ketone in the presence of a dehydration catalyst. This dehydration produces a third organic fraction comprising an alkenyl aromatic compound, and the aromatic alkyl ketone as primary products. The fixed-bed reactor (216) provides an efficient platform for the reaction, ensuring high conversion rates and selectivity by leveraging optimized catalyst systems and reaction conditions. This helps in advancing the chemical synthesis by yielding high-value intermediates for downstream applications. The step of performing dehydrating (112) the second organic fraction enables a solvent free and effluent free process which eliminates requirement of other processes such as effluent intensive mineral acid-based treatment to the organic fractions.

In a related embodiment, at step of dehydrating (112) the aromatic alkyl alcohol is converted into the alkenyl aromatic compound at a temperature ranging between 30-130°C. Preferably, the aromatic alkyl alcohol is converted into the alkenyl aromatic compound at a temperature ranging between 45-120°C.

In an embodiment, a step of distilling (114) the third organic fraction in a second distillation unit (218) is carried out to obtain a refined aromatic alkyl ketone. By ensuring the removal of residual alkenyl aromatic compounds and other impurities, a highly purified aromatic alkyl ketone is obtained which is suitable for use in advanced chemical synthesis or end-product formulations. Further, by optimizing the distillation parameters, such as temperature and pressure, this method enhances the efficiency and quality of the separation, contributing to the overall stability and precision of the production method.

In a related embodiment, the step of distilling (114) the third organic fraction in the second distillation unit (218) is carried out at a temperature ranging between 50-120°C to obtain a refined aromatic alkyl ketone under vacuum. Preferably, the step of distilling (114) the third organic fraction in the second distillation unit (214) is carried out at a temperature ranging between 60-110°C.

In an embodiment of the present disclosure, referring to figure 2, a system (200) for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone disclosed. The system incorporates a range of specialized units, including distillation units, fixed-bed reactors, and separation modules, each tailored to perform specific functions within the continuous conversion pathway. Initially, the aromatic alkyl hydroperoxide undergoes controlled reactions facilitated by optimized reaction conditions, such as precise temperature and pressure settings, to ensure efficient transformation into intermediates like aromatic alkyl alcohol. Subsequently, these intermediates are processed through a fixed-bed reactor to undergo dehydration, yielding an alkenyl aromatic compound.

The process continues with advanced distillation techniques in dedicated units to refine and purify the aromatic alkyl ketone, ensuring high yield and purity for downstream applications. This system exemplifies a robust integration of chemical engineering principles, leveraging efficient material handling, catalytic activity, and energy optimization to deliver a scalable, reliable solution for producing aromatic alkyl ketones at industrial scales. Its modular design allows for operational flexibility, making it adaptable to varying feedstock compositions and production demands.

In an embodiment, the system (200) comprises a first feed tank unit (202) enabled for storing the reactant such as aromatic alkyl hydroperoxide and a second feed tank reactor (204) enabled for storing the premix comprising the catalyst solution. Both feed tanks are equipped with appropriate safety features, such as pressure relief valves and inert gas blanketing, to maintain the stability of their respective contents. These units deliver the aromatic alkyl hydroperoxide and the premix in a controlled manner, ensuring efficient mixing and reaction in subsequent reactor stages.

In a further embodiment, the system (200) comprises of a first reactor (206), for reacting an aromatic alkyl hydroperoxide received from the first feed tank reactor (202) and the premix comprising of a catalyst solution from the second feed tank reactor (204) to obtain a reaction mass A. The reactor is engineered to ensure precise control over reaction parameters, such as temperature, pressure, and mixing intensity, to optimize the interaction between the reactants and the catalyst. The premix comprising of the catalyst solution is prepared to ensure uniform distribution and enhanced catalytic efficiency, driving the selective conversion of the aromatic alkyl hydroperoxide into desired products. By maintaining optimal residence time and ensuring efficient heat transfer within the reactor, the system minimizes side reactions and maximizes the formation of the target reaction mass A. Also, the hazard associated with the alkyl aromatic hydroperoxide accumulation is avoided.

In a related embodiment, referring to figures 2 and 3, the first reactor (206) comprises of one or more cylindrical vessels with inlets and outlets.

In another related embodiment, the first reactor (206) is enabled for the completion of 85-99% of reaction. Preferably, the first reactor (206) is enabled for the completion of 95-99% of the reaction.

In yet another related embodiment, a fluid overflow management system (310) is configured for transferring an overflow of reaction mass A from the first reactor (206) to a second reactor (208). This ensures that excess reaction mass is efficiently managed, preventing any disruption in the operation of the first reactor (206) while maintaining a continuous process flow. The fluid overflow management system (310) may include components such as level sensors, control valves, and transfer pipelines to monitor and regulate the flow of reaction mass in real-time. By automating the transfer process, the fluid overflow management system (310) minimizes the risk of spillage, overpressure, or process inefficiencies.

In an embodiment, a second reactor (208) is configured for receiving overflow of reaction mass A from the first reactor (206) to obtain a reaction mass B. The second reactor (208) is designed to handle the additional volume of reaction mass efficiently, maintaining optimal reaction conditions such as temperature and pressure to ensure the continued progression of the desired chemical transformation. By receiving the overflow, the second reactor (208) ensures a smooth, continuous flow of material through the system, preventing any build-up or disruption in the first reactor. The reaction mass B produced in the second reactor may contain intermediate products or altered reactants, setting the stage for further separation, purification, or transformation steps in the overall process. The design of the second reactor is integral to scaling up the reaction while maintaining high conversion efficiency and product consistency.

In a related embodiment, the second reactor (208) is enabled for the completion of the rest 1-15% of the reaction. Preferably, the second reactor (208) is enabled for the completion of the rest 1-5% of the reaction.

In another related embodiment, the first reactor (206) and the second reactor (208) are selected from at least one of, thermal decomposition stirred tank reactor, catalytic stirred tank reactor, multi-phase stirred tank reactor, a continuous stirred tank reactor (CSTR), and the like.
In yet another embodiment, the first reactor (206) and the second reactor (208), or a series of continuous reactors is a continuous flow reactor may be selected from at least one of continuous flow reactor, slurry flow reactor, turbo flow reactor, pinch flow reactor, microflow reactor, customised flow reactor, and the like.
Preferably, the first reactor (206) and the second reactor (208) are continuous stirred tank reactors (CSTR).

In a related embodiment, the first reactor (206) and the second reactor (208) comprise of at least one stirring apparatus (302, 304). Both the first reactor (206) and the second reactor (208) are equipped with at least one stirring apparatus (302, 304) to ensure thorough mixing of the reactants and maintain homogeneity within the reaction mass. The first reactor (206) comprises a stirring apparatus (302). The second reactor (208) is equipped a stirring apparatus (304). The stirring apparatus (302, 304) is optimized to provide efficient agitation, which enhances heat and mass transfer, prevents localized overheating, and ensures consistent catalytic activity throughout the reaction medium. By maintaining uniform conditions, the system minimizes the formation of byproducts and promotes the efficient progression of the chemical reaction. The integration of stirring apparatus (302, 304) in both reactors highlights the system’s focus on precision and scalability, supporting the production of reaction intermediates essential for the downstream conversion to aromatic alkyl ketones.

In a related embodiment, the stirring apparatus (302, 304) is selected from at least one of a paddle stirrer, helical ribbon stirrer, propeller type stirrer, pitch blade type stirrer, and the like. Preferably, the stirring apparatus (302, 304) is the pitch blade type stirrer.

In the decomposition of cumene hydroperoxide (CHP), stirrer systems are essential for ensuring efficient mixing and promoting optimal reaction conditions in biphasic mixing, and/or multiphasic mixing. Rushton turbines and pitch blade type stirrers are commonly used due to their high shear, which aids in heat and mass transfer, ensuring effective decomposition of CHP into acetophenone.

Additionally, stirrers designed for interphase mixing reactions, such as turbine or disc-stirrer systems, are often employed when the reaction involves immiscible phases (liquid-liquid or liquid-solid), ensuring effective dispersion and contact between the phases. These stirrers facilitate the generation of large interphase areas, which are crucial for reactions involving multiple phases, such as when dealing with organic solvents and aqueous phases.

In another related embodiment, the stirring apparatus (302, 304) has a stirring speed ranging between 100-1500 rpm. Preferably, the stirring speed ranges between 100-1000 rpm.

By referring to figure 3, the first reactor (206) and the second reactor (208) assembly is depicted. The first reactor (206) and the second reactor (208) may comprise one or more temperature indicator sensors housed in a thermowell (312, 314). The first reactor (206) further may comprise a temperature gauge (not shown in figure) enabled for local temperature indications. The first reactor (206) may comprise a jacket enabled for cooling the reaction mass A. The first reactor (206) comprises of one or more cylindrical vessel with inlets and outlets. The first reactor (206) comprises of a first feed inlet (306) and a second feed inlet (308). The first feed inlet (306) is enabled for receiving the aromatic alkyl hydroperoxide and the second feed inlet (308) is enabled for receiving the premix. The first reactor (206) and the second reactor (208) are connected with the fluid overflow management system (310) for transfer of the reaction mass A from first reactor (206) to the second reactor (208). The first reactor (206) comprises a stirring apparatus (302) enabled for stirring the reaction mass A. The second reactor (208) comprise the stirring apparatus (304) enabled for stirring the reaction mass B. The reaction mass B comprises of crude mass of aromatic alkyl ketone, aqueous effluents, alkyl aromatic, phenol, and aromatic alkyl alcohol.

In an embodiment, the second reactor (208) may comprise of one or more feed inlets (316), (318). The one or more feed inlets of the second reactor may be enabled for receiving one or more reactants such as catalyst, aromatic alkyl hydroperoxide, and for receiving the premix, if required to adjust pH or concentration of the reactants.

In an alternative embodiment, the reactor assembly (300) may include more than two reactors depending on the scale and volume of the reaction. The system may comprise, one or more subsequent reactors as a second reactor (208) set-up. The one or more subsequent reactors as a second reactor (208) may be a second reactor or a second reactor setup comprising a series of one or more continuous stirred tank reactors. The one or more subsequent reactors are optionally interconnected with overflow management system (310). For larger reaction volumes or scaled-up processes, additional Continuous Stirred Tank Reactors (CSTR) can be incorporated to enhance throughput, adjust reaction residence time, and control over the reaction kinetics and to reduce overall conversion time.

The system may comprise of a combination of Continuous Stirred Tank Reactors (CSTR) and Continuous Stirred Reactors (CSR), as needed, to accommodate varying reaction conditions and achieve optimal performance. These reactors can be connected in series or parallel configurations, with the overflow management system facilitating the transfer of reaction mass between them.

The arrangement of two or more continuous stirred tank reactors allows for better catalyst distribution, ensuring higher efficiency, and consistent product quality. This setup also prevents back mixing, allowing for distinct reaction stages that improve selectivity and yield, while providing precise control over temperature, pressure, and concentration by adjusting the flow rates of reactants, catalyst pre-mix products, intermediate product. The flexible configuration supports scalability for industrial processes and enhances efficiency by enabling continuous operation with minimal downtime.

In an embodiment, a layer separation unit (210) is configured for separating the reaction mass B into a first organic fraction and an aqueous layer, wherein the first organic fraction comprising an alkyl aromatic, an aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone. The first organic fraction, obtained after separation, contains a mixture of the alkyl aromatic, the aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone. This layer separation unit (210) operates based on differences in the density and polarity of the components, facilitating the effective partitioning of the reaction mass into its respective phases. The organic fraction, rich in valuable intermediates like the aromatic alkyl ketone and aromatic alkyl alcohol, is further processed or refined for downstream applications, while the aqueous layer, which may contain water-soluble byproducts or residual reactants, is disposed of or treated accordingly.

In a related embodiment, the layer separation unit (210) may be selected from at least one of gravity separator, centrifugal separator, liquid-liquid separator, membrane separator, electrostatic separator, tilted-plate separator, rotary separator, and the like.

In an embodiment, the system (200) comprises a washing unit (212) for washing the first organic fraction comprising the alkyl aromatic, the aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone to remove the acidity and the residual metal content before distillation of the first organic fraction. The washing unit (212) is a multi-stage system designed to purify organic and alkaline layers by removing impurities through water washing. The washing unit (212) may be configured to treat and wash the first organic fraction. Particularly, the organic fraction is washed with water to remove soluble impurities.

In a related embodiment, the alkyl aromatic is selected from at least one of dialkyl benzene, p-tert-butyl phenyl-2-propane, 2-phenyl-2-butane, 2-naphthyl-2-propane, 2-biphenyl-2-propane, cumene (2-phenyl-2-propane) , and the like. Preferably, the alkyl aromatic is cumene (isopropylbenzene).

In another related embodiment, the aromatic alkyl alcohol is selected from at least one of dialkyl benzyl alcohol, 2-phenyl-2-propanol, 1-phenyl-2-butanol, 2-(p-tert-butyl phenyl)-2- propanol, 2-phenyl-2-butanol, 2-naphthyl-2-propanol, 2-biphenyl-2-propanol and dimethyl benzyl alcohol (DMBA, 2-phenyl-2-propanol), dimethyl benzyl alcohol, and the like. Preferably, di-alkyl aromatic alcohol is dimethyl benzyl alcohol.
In a related embodiment, dimethyl benzyl alcohol may be at least one selected from substituted dimethyl benzyl alcohol, nitro- dimethyl benzyl alcohol, halogenated - dimethyl benzyl alcohol, hydroxy - dimethyl benzyl alcohol, methoxy- dimethyl benzyl alcohol, and the like.
In yet another related embodiment, the washing unit (212) may be selected from counter-current washing unit, agitated vessels with settlers, packed bed wash columns, spray columns, centrifugal extractors, coalescing wash columns, and the like.

In an embodiment, a first distillation unit (214), is configured for separating the alkyl aromatic from the first organic fraction to obtain a second organic fraction comprising the aromatic alkyl alcohol and the aromatic alkyl ketone. Through the process of distillation, the alkyl aromatic, having a distinct boiling point from the other components, is selectively evaporated and separated, leaving behind a second organic fraction enriched with the aromatic alkyl alcohol and the aromatic alkyl ketone. The first distillation unit (214) operates by applying controlled heat and pressure, allowing for efficient separation based on the differences in volatility of the compounds. The second organic fraction, now containing the key products, can be further processed or purified to isolate the desired aromatic alkyl ketone for final use.

In an embodiment, the fluidized bed reactor or the fixed bed reactor (216) is configured for dehydrating the aromatic alkyl alcohol from the second organic fraction into an alkenyl aromatic compound forming a third organic fraction comprising the alkenyl aromatic compound, and the aromatic alkyl ketone.

This transformation occurs through the application of heat and the presence of a suitable catalyst within the fluidized bed reactor or the fixed bed reactor (216), which promotes the elimination of water from the aromatic alkyl alcohol, resulting in the formation of the alkenyl aromatic compound. The fixed-bed design of the reactor (216) ensures efficient contact between the reactants and catalyst, providing consistent reaction conditions that enhance conversion rates. As a result, the third organic fraction comprises a mixture of the alkenyl aromatic compound and the aromatic alkyl ketone, both valuable intermediates in further chemical processing. The reactor is optimized to maintain the necessary temperature and flow dynamics, preventing byproduct formation and ensuring high yield and selectivity for the desired compounds, thus advancing the overall process toward the final aromatic alkyl ketone product.

In a related embodiment, the alkenyl aromatic compound converting the aromatic alkyl alcohol is at least one of alkenyl aromatic, p-tert-butyl phenyl-2-propene, 2-phenyl-2-butene, 2-naphthyl-2-propene, 2-biphenyl-2-propene and cumene (2-phenyl-2-propene (alpha-methyl styrene), divinylbenzene, vinyl toluene, vinyl xylene, and the like. Preferably, the vinyl aromatic compound obtained is alpha-methyl styrene.

The alpha methyl styrene obtained may be at least one of p-methyl-α-methyl styrene, p-chloro-α-methyl styrene, p-nitro-α-methyl styrene, α-chloro-α-methyl styrene, naphthyl styrene, α-hydroxy-α-methyl styrene, and the like.

In another related embodiment, the fluidized or fixed bed reactor (216) comprises a catalytic bed of at least one of zeolite, silica-alumina, heteropoly acids, solid-acid catalyst, and the like. Preferably, the catalyst bed is made of solid-acid catalyst. These materials are chosen for their ability to facilitate the dehydration of aromatic alkyl alcohols into alkenyl aromatic compounds efficiently.

Among these, the solid acid catalyst is preferred due to its high catalytic activity, stability, and selectivity, which make it particularly effective in promoting the desired reaction while minimizing byproducts. Also, separation from product is easier. The use of this catalyst in the fluidized or fixed bed reactor (216), ensures optimized reaction rates, enhanced product quality, and conversion of impurities such as aromatic alkyl alcohol.

In yet another related embodiment, the fluidized or fixed bed reactor (216) may be selected from at least one of fluidized catalyst bed reactor, adiabatic fixed-bed reactor, tubular fixed-bed reactor, multi-tubular fixed-bed reactor, trickle bed reactor, packed bed reactor, and the like.

In an embodiment, a second distillation unit (218) is configured for the distillation of the third organic fraction to obtain a refined aromatic alkyl ketone. The second distillation unit (218) comprises of two outlets, one outlet is configured for obtaining the refined aromatic alkyl ketone and the second outlet is configured for removing residual by-products, such as the alkenyl aromatic compound or any remaining impurities. This distillation unit operates by applying precise heat and pressure conditions to selectively separate the aromatic alkyl ketone from the alkenyl aromatic compound and any remaining impurities based on their distinct boiling points. This distillation ensures that the aromatic alkyl ketone is isolated in a highly refined state, suitable for downstream applications or as a final product. By optimizing the distillation parameters, such as reflux ratio and column design, the unit achieves high separation efficiency, removing unwanted compounds while preserving the quality and purity of the aromatic alkyl ketone. This step is crucial for obtaining the desired product with minimal contaminants, contributing to the overall success of the chemical process and enhancing its industrial viability.

In advanced distillation processes, units can be arranged in parallel to increase throughput or in series for stepwise refinement, enhancing separation efficiency and product purity. Thin film evaporators can be used for efficient heat transfer and evaporation, especially with high-viscosity or temperature-sensitive materials. Additionally, using more than two distillation units in a multistage setup improves separation precision, ensuring higher purity and yield in complex mixtures. This approach optimizes both efficiency and scalability in industrial applications.

In a related embodiment, the first distillation unit (214) and the second distillation unit (218) are selected from at least one of a fractional distillation unit, a steam distillation unit, a molecular distillation unit, a short-path distillation unit, a high vacuum distillation unit, and the like. Preferably, the first distillation unit (214) and the second distillation unit (218) are high vacuum distillation unit.

In another related embodiment, the pressure in the first distillation unit (214) and the second distillation unit (218) range between 10-50mmHg. Preferably, the pressure in the first distillation unit (214) and the second distillation unit (218) range between 20-40mmHg.

Further, the aromatic alkyl ketone obtained is at least one of, 4-hydroxyacetophenone, propiophenone, naphthalene, monoaryl compounds such as phenols, cumyl alcohol and α-methyl styrene, biphenyl compounds, substituted aryl compounds such as cresols, alkyl phenols, acetophenone, and the like. Preferably, the aromatic alkyl ketone is acetophenone.

In one embodiment, the system comprises one or more reactors, each specifically designed to catalytically convert hydroperoxides into aromatic alkyl ketones. These reactors are configured to operate either in series or parallel, allowing for continuous processing and efficient management of reaction conditions. The arrangement ensures optimal flow control, maintaining consistent reaction parameters, and facilitating effective interaction between the hydroperoxide feed and catalyst. This setup enhances throughput, improves yield, and ensures the catalytic reaction proceeds with high selectivity towards the desired ketones, while minimizing byproducts.

Continuous flow systems, like reactor setups, enable precise control over reactant flow and mixing, ensuring consistent exposure of reactants to optimal reaction conditions. This uniformity reduces the time needed to achieve high conversion rates while maintaining product integrity. Additionally, effective separation techniques allow for the rapid removal of byproducts and unreacted components, which helps to preserve the desired product's purity and selectivity.

Unlike batch process, continuous process as disclosed rarely require shutdowns, with only planned maintenance periods. Automation and monitoring systems reduce the need for dedicated manpower. Additionally, the CHP inventory is low, with less than 1% working concentration in the overall process train, which reduces associated process risks. Process safety is also at a lower risk due to the controlled inventory levels of CHP. The throughput for crude ACP represents a 169% increase over batch processing. Furthermore, the space and time required in a continuous process is reduced to multi fold compared to a batch process, leading to significant efficiency improvements. Additional advantages of continuous process over the batch process are the low CHP concentration throughout the process which rules out the process safety hazard associated with multi-fold increase in temperature and pressure associated with decomposition of the higher concentration of CHP.

This overall integrated approach as disclosed herein, leads to maximize efficiency, minimize waste, and deliver high-quality outputs in a shorter timeframe, making the process highly scalable and commercially advantageous.

Examples are set forth below to further illustrate the nature of the disclosure and the manner of carrying it out. However, the disclosure should not be considered as being limited to the details thereof.
Examples:
Comparative Example 1: Batch type one pot synthesis of aromatic alkyl ketone from aromatic alkyl hydroperoxide
To a clean reaction kettle equipped with a reflux condenser, charge 320g water, charge Ferrous sulphate heptahydrate (7.3g), Copper sulphate pentahydrate (3.23g), Sulfuric acid (1.3g). Heat it to 80oC under stirring. Start slow addition of 666g Cumene hydroperoxide solution (30 wt.% in Cumene) in 1 hr. Maintaining reaction mass temperature 80oC for four hours. Cool the reaction mass and separate the organic fraction. Wash organic fraction with water and separate 582g crude Acetophenone in Cumene. (crude yield: 90%).
HPLC Analysis shows that 16% CHP remain in the reaction after complete addition of CHP (0 h sample). 99% Conversion of CHP is observed after 3-4 hrs.
A batch process refers to a method that involves a sequence of steps followed in a specific order, typically consisting of startup, processing time, product discharge, and cleanup, with each batch cycle adhering to a defined cycle time. The process is scheduled to ensure proper timing between movements to different stages. In such processes, a whole unit of products is produced in each cycle and fouling or errors are more likely when fouling expectations are high. The product life span is short, around 1-2 years, and the process costs are comparable to other methods. The equipment used is of medium cost, and process control is typically managed section-wise.
Batch processes often require frequent shutdowns and dedicated manpower for optimal operation. Given the high energetic nature of CHP (with a 16% working concentration), the process necessitates high inventory management and specific storage requirements. Additionally, process safety is a critical concern due to the elevated levels of CHP inventory in the reaction crude, making the process high risk. The throughput for crude ACP is 1.244 kg/day.
Example 2: Continuous production of aromatic alkyl ketone from aromatic alkyl hydroperoxide
In Example 2, the continuous process for the production of aromatic alkyl ketone from aromatic alkyl hydroperoxide i.e. Cumene hydroperoxide solution (30 wt.% in Cumene) was carried out in a continuous reactor assembly. The catalyst solution was prepared by dissolving CuSO₄.5H₂O, FeSO₄.7H₂O, and H₂SO₄ in water and heating the mixture to 80°C under stirring to achieve a clear, light blue solution with a pH below 2. Cumene hydroperoxide (CHP) was then added dropwise at a temperature of 75-80°C, with the reaction progress monitored visually through colour changes and by measuring the CHP concentration.
In the dual-CSTR setup, CHP and the catalyst solution were fed into the first CSTR to obtain reaction mass A, which was then transferred to the subsequent CSTR via a fluid overflow management system. A residence time of 1 hour was maintained in each CSTR to produce reaction mass B. About 85-99% of the reaction is completed in the first reactor and about 1-15% of the reaction is completed in the second reactor. Afterward, reaction mass B was transferred to a layer separation unit at 30°C, where the aqueous layer and the first organic fraction were separated. The process resulted in a first organic fraction composition consisting of aromatic alkyl ketones, alkyl aromatic, phenol, and aromatic alkyl alcohol. The conversion efficiency exceeded 99%, with residual CHP in the organic fraction maintained below 0.5%.

The vacuum distillation setup equipped with a packed column and high vacuum distillation (HVD) assembly was used for continuous cumene recovery. The first organic fraction, containing approximately 60-65% cumene, was charged into the distillation unit and distilled under vacuum conditions (20-100 mmHg). The temperature was carefully controlled to collect distillation cuts at various temperature ranges, yielding pure cumene and a second organic fraction. The pure cumene, collected as a colourless liquid, had a purity of ≥99%, while the bottom mass was a dark brown residue. The yield of pure cumene ranged from 90-96%.

The continuous operation of this process significantly enhanced throughput, enabling a streamlined and uninterrupted reaction process that boosted overall productivity. In the DMBA conversion step, the second organic fraction was treated with a solid acid catalyst in a fixed bed reactor at 140-160°C for WHSV 0.5 to 2 h-1 to convert DMBA to AMS and produce a third organic fraction. The third organic fraction was then subjected to vacuum distillation (20-100 mmHg) in a second distillation unit, where pure acetophenone was collected at temperature between 69-100°C. The acetophenone obtained from this process exhibited a purity of ≥99% and a yield of 85-95%. This process efficiently converted CHP to acetophenone with high purity and yield, optimizing the overall conversion and ensuring high-quality acetophenone for downstream applications.
In a continuous process, while the TD24 value is maintained between 75-85°C, while the throughput for crude ACP is 2.096 kg/day.

The presently disclosed method and system for conversion of aromatic alkyl hydroperoxide to aromatic alkyl ketone may have the following advantageous functionalities over the conventional art:
• Reduced reaction time
• High yield and selectivity
• Improved product purity
• Process scalability
• Lower process hazard
• Efficient catalyst utilization
• Controlled reaction conditions
• Process Sustainability
• Minimized side reactions
• Increased throughput
• Cost-effective production of aromatic alkyl ketones
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 would be encompassed within the scope of this disclosure. The embodiments, examples and alternatives of the preceding paragraphs or the description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible. , Claims:WE CLAIM:
1. A method (100) for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone, comprising:
mixing (102) a catalyst solution with mineral acid and water to obtain a premix;
reacting (104) the aromatic alkyl hydroperoxide and the premix into a first reactor (206) to obtain a reaction mass A;
transferring (106) an overflow of the reaction mass A from the first reactor (206) to a second reactor (208) via a fluid overflow management system (310) to obtain a reaction mass B;
separating (108) the reaction mass B in a layer separation unit (210) to obtain an aqueous layer and a first organic fraction, wherein the first organic fraction comprises an alkyl aromatic, an aromatic alkyl alcohol, phenol, and the aromatic alkyl ketone;
distilling (110) the first organic fraction in a first distillation unit (214) to separate the alkyl aromatic and to obtain a second organic fraction comprising the aromatic alkyl alcohol, and the aromatic alkyl ketone;
dehydrating (112) the second organic fraction comprising the aromatic alkyl alcohol in a fluidized or fixed bed reactor (216) to obtain a third organic fraction comprising an alkenyl aromatic compound, and the aromatic alkyl ketone; and
distilling (114) the third organic fraction in a second distillation unit (218) to obtain a refined aromatic alkyl ketone.
2. The method (100) as claimed in claim 1, wherein reacting (104) the aromatic alkyl hydroperoxide and the premix in the first reactor (206) is carried out to obtain reaction mass A for completion of 85-99% of the reaction, and transferring (106) the reaction mass A to the second reactor is carried out for the completion of rest 1-15% of the reaction.
3. The method (100) as claimed in claim 1, wherein a residence time of the aromatic alkyl hydroperoxide in the first reactor (206) ranges from 0-2 hours and at a temperature ranging from 50-100°C.
4. The method (100) as claimed in claim 1, wherein the catalyst solution comprises one or more hydrated metal sulphates.
5. The method (100) as claimed in claim 1, wherein the pH of the premix is 1-5.
6. The method (100) as claimed in claim 1, wherein the premix comprises of one or more hydrated metal sulphates and at least one mineral acid in a ratio ranging between 0.5:0.5:1 to 3:3:1.
7. The method (100) as claimed in claim 1, wherein separating (108) the reaction mass B into an aqueous layer and first organic fraction is carried out at a temperature ranging from 10-50°C.
8. The method (100) as claimed in claim 1, wherein washing (109) the first organic fraction in the washing unit (206) is carried out to remove the acidity and residual metal content before first distillation.
9. The method (100) as claimed in claim 1, wherein the first organic fraction comprises alkyl aromatic in the range of 50-70%, aromatic alkyl ketone in the range of 20-40%, phenol in ppm, and the aromatic alkyl alcohol in the range of 2-8%.
10. The method (100) as claimed in claim 1, wherein at step of dehydrating (112) the aromatic alkyl alcohol is converted into the alkenyl aromatic compound at a temperature ranging between 30-130 °C.
11. The method (100) as claimed in claim 1, wherein distilling (110) the first organic fraction in the first distillation unit (214) is carried out to separate the alkyl aromatic and to obtain a second organic fraction and distilling (114) the third organic fraction in the second distillation unit (218) is carried out at a temperature ranging between 50-120°C to obtain a refined aromatic alkyl ketone.
12. A system (200) for conversion of an aromatic alkyl hydroperoxide to an aromatic alkyl ketone, comprising:
a first reactor (206), for reacting an aromatic alkyl hydroperoxide and a premix of a catalyst solution, water, and mineral acid to obtain a reaction mass A;
a fluid overflow management system (310), for transferring an overflow of reaction mass A from the first reactor (206) to a second reactor (208),
a second reactor (208), for receiving overflow of reaction mass A from the first reactor (206) to obtain a reaction mass B, wherein the first reactor (206) and the second reactor (208) comprise of at least one stirring apparatus (302, 304);
a layer separation unit (210), for separating the reaction mass B into a first organic fraction and an aqueous layer, wherein the first organic fraction comprising an alkyl aromatic, an aromatic alkyl alcohol, a phenol, and the aromatic alkyl ketone;
a first distillation unit (214), for separating the alkyl aromatic from the first organic fraction and to obtain a second organic fraction comprising the aromatic alkyl alcohol and the aromatic alkyl ketone;
a fluidized or fixed bed reactor (216), for dehydrating the aromatic alkyl alcohol from the second organic fraction into an alkenyl aromatic compound forming a third organic fraction comprising the alkenyl aromatic compound, and the aromatic alkyl ketone; and
a second distillation unit (218), for distillation of the third organic fraction to obtain a refined aromatic alkyl ketone.
13. The system (200) as claimed in claim 12, wherein the first reactor (206) and the second reactor (208) are selected from at least one of, thermal decomposition stirred tank reactor, catalytic stirred tank reactor, multi-phase stirred tank reactor and continuous stirred tank reactor (CSTR).
14. The system (200) as claimed in claim 12, wherein the stirring apparatus (302, 304) is selected from at least one of a paddle stirrer, helical ribbon stirrer, propeller type stirrer, and pitch blade type stirrer.
15. The system (200) as claimed in claim 12, wherein the stirring apparatus (302, 304) has a stirring speed ranging between 100-1000 rpm.
16. The system (200) as claimed in claim 12, wherein the first reactor (206) is enabled for the completion of 85-99% of reaction, and wherein the second reactor (208) is enabled for the completion of the rest 1-15% of the reaction.
17. The system (200) as claimed in claim 12, wherein the second reactor comprises a series of one or more continuous stirred tank reactors.
18. The system (200) as claimed in claim 12, wherein the fixed bed reactor (216) comprises a catalytic bed of at least one of zeolite, silica-alumina, heteropoly acids, and solid-acid catalyst.
19. The system (200) as claimed in claim 12, comprises a washing unit (212) for washing the first organic fraction comprising the alkyl aromatic, the aromatic alkyl alcohol, the phenol, and the aromatic alkyl ketone.
20. The system (200) as claimed in claim 12, wherein the first distillation unit (214) and the second distillation unit (218) are selected from at least one of a fractional distillation unit, a steam distillation unit, a molecular distillation unit, a short-path distillation unit, and a high vacuum distillation unit.
21. The system (200) as claimed in claim 12, wherein the pressure in the first distillation unit (214) and the second distillation unit (218) range between 10-50mmHg.
22. The system (200) as claimed in claim 12, wherein the system comprises the reactors being operatively connected in series or parallel to enable continuous processing and efficient reaction control.
Dated this 13th day of March 2025