Fluidized Reactor for Heavy Aromatic Conversion
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Solution Overview
Problem
Current methods for producing light aromatics from heavy aromatics face challenges such as harsh reaction conditions, difficulty in catalyst regeneration and recycling, and strict requirements on initial catalyst activity, leading to inefficient conversion and utilization of resources.
Innovation Solution
A method involving a fluidized reactor system where C9+ heavy aromatics are contacted with a catalyst in the presence of hydrogen, allowing for the conversion of heavy aromatics into C6-C8 light aromatics, with the option to recycle C9+ aromatic components for further reaction, using a catalyst with a carrier and active metal components supported on zeolites, inorganic oxides, and clay, under conditions of 250-750°C and 0-6 MPa pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fixed bed reactor is used for hydrodealkylation of heavy aromatics, then conversion of heavy aromatics to light aromatics is achieved, but catalyst regeneration and recycling becomes difficult
Solution Approach 1:
The patent transitions from a fixed bed reactor to a fluidized bed reactor, making the catalyst dynamic and mobile. This allows the catalyst to be continuously circulated, regenerated, and recycled, solving the difficulty of catalyst maintenance in fixed bed systems while maintaining high conversion efficiency of heavy aromatics to light aromatics.
Solution Approach 2:
The patent implements a catalyst regeneration system where spent catalyst is continuously removed, regenerated externally, and returned to the reactor. This discarding and recovering approach solves the problem of catalyst deactivation and enables continuous operation, addressing both conversion efficiency and catalyst renewability.
2Productivity
If harsh reaction conditions are applied to convert heavy aromatics, then conversion rate improves, but energy consumption and operational complexity increase
Solution Approach 1:
The patent optimizes reaction parameters including temperature (400-600°C), pressure (1-4 MPa), and hydrogen-to-hydrocarbon ratio (3-6) to achieve high conversion rates without excessively harsh conditions. The fluidized bed reactor enhances heat and mass transfer, allowing milder operating conditions compared to conventional fixed bed systems, thus reducing energy consumption while maintaining productivity.
Solution Approach 2:
The patent replaces the mechanical fixed bed system with a fluidized bed system where gas flow suspends and circulates catalyst particles. This substitution improves contact between reactants and catalyst, enhancing reaction efficiency at lower energy input and reducing the need for harsh reaction conditions.
3Reliability
If strict requirements on initial catalyst activity are imposed, then reaction performance is maintained, but catalyst selection and process flexibility are limited
Solution Approach 1:
The continuous catalyst regeneration system allows the use of catalysts with lower initial activity requirements, as their performance is maintained over time through regeneration. This increases flexibility in catalyst selection while ensuring stable reaction performance, resolving the contradiction between reliability and adaptability.
Solution Approach 2:
The patent implements continuous catalyst circulation and regeneration, ensuring that active catalyst is continuously available in the reactor. This continuous action maintains stable reaction performance regardless of initial catalyst activity variations, allowing greater flexibility in catalyst formulation and selection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables efficient and stable long-period operation, improving the conversion of heavy aromatics into high-value light aromatics with strong feedstock adaptability and flexibility, addressing the inefficiencies and resource utilization issues in existing processes.
Implementation Method 1
contacting a feedstock comprising heavy aromatic(s) with a catalyst in a fluidized reactor for lightening reaction in the presence of hydrogen
Data Source
AI summary
A method for producing light aromatics, includes the steps of: i) contacting a feedstock comprising heavy aromatic(s) with a catalyst in a fluidized reactor for aromatics lightening reaction in the presence of hydrogen to obtain a product rich in C6-C8 light aromatic(s) and a spent catalyst, wherein the heavy aromatic is one or more selected from C9+ aromatics; ii) separating the resulted product rich in C6-C8 light aromatic(s) to obtain hydrogen, a non-aromatic component, C6-C8 light aromatic(s) and a C9+ aromatic component; and iii) recycling at least a part of the C9+ aromatic component to the fluidized reactor. The method has strong adaptability to feedstocks and high flexibility in operation and allows a long-period stable operation. The method can produce high-value light aromatics from heavy aromatics that are difficult to be treated and utilized.