Aromatization Catalyst Reactor Pressure and Flow Optimization
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Solution Overview
Problem
Current aromatization processes for lower hydrocarbons, such as ethane, propane, and butane, are limited by low pressures and gas flow rates, which hinder increased productivity and catalyst stability, as higher hydrogen partial pressures inhibit dehydrogenation and promote undesirable hydrogenolysis reactions.
Innovation Solution
Operating at pressures greater than 0.4 MPa with a gas hourly space velocity of at least 4,000 ml·(g of Cat)−1·h−1 and introducing hydrogen in amounts from 0.1 to 29 volume percent in the feed stream to a fixed bed catalyst reactor, enhancing ethane conversion and aromatics productivity while maintaining long-term catalyst performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher pressures are used to increase productivity, then aromatics productivity improves, but hydrogenolysis reactions are promoted and dehydrogenation is inhibited
Solution Approach 1:
The patent changes multiple parameters simultaneously: uses higher pressures (0.5-10 MPa) combined with high GHSV (4000-15000 ml/(gCat·h)), and introduces hydrogen co-feed (0.1-29 vol%). This parameter combination resolves the contradiction by using high space velocity to compensate for hydrogenolysis promotion, while hydrogen co-feed maintains dehydrogenation activity despite elevated pressure
Solution Approach 2:
The patent dynamically adjusts operating conditions by introducing hydrogen co-feed that can be varied (0.1-29 vol%) to maintain optimal dehydrogenation activity. The high GHSV provides dynamic compensation for pressure-induced hydrogenolysis, allowing the system to adapt to pressure effects while maintaining productivity
2Productivity
If higher gas flow rates are used to increase productivity, then aromatics productivity improves, but catalyst contact time decreases
Solution Approach 1:
The patent uses extremely high GHSV values (4000-15000 ml/(gCat·h)) combined with high pressure (0.5-10 MPa). The high pressure compensates for reduced contact time by increasing reaction rate, while the high space velocity maintains productivity. This parameter combination allows short contact times to be tolerable
3Productivity
If more lower hydrocarbon is processed per gram of catalyst to improve productivity, then aromatics productivity improves, but catalyst stability decreases
Solution Approach 1:
Hydrogen co-feed acts as an intermediary that protects the catalyst. By introducing hydrogen (0.1-29 vol%), the patent prevents excessive deactivation that would occur at high space velocities, allowing sustained high productivity without sacrificing catalyst stability
Solution Approach 2:
The patent uses dynamic operating conditions with high GHSV (4000-15000 ml/(gCat·h)) combined with hydrogen co-feed and elevated pressure. This dynamic approach allows the catalyst to operate at high productivity levels while the hydrogen and pressure conditions prevent irreversible deactivation
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 approach achieves higher ethane conversion and aromatics productivity, extending catalyst longevity by optimizing reaction conditions and hydrogen co-feed, even at elevated pressures and flow rates.
Implementation Method 1
converting the hydrocarbon having 2 to 4 carbon atoms to form an outlet stream comprising an aromatic hydrocarbon
Data Source
AI summary
A method for the aromatization of hydrocarbons, comprising: introducing a feed stream to an aromatization catalyst in a fixed bed reactor wherein the feed stream comprises a hydrocarbon having 2 to 4 carbon atoms, converting the hydrocarbon having 2 to 4 carbon atoms to form an outlet stream comprising an aromatic hydrocarbon; wherein the feed stream is introduced at a GHSV of greater than or equal to 4,000 milliliters per gram of catalyst per hour (ml·g−1 Cat·h−1), and a pressure of greater than or equal to 0.4 MPa. The feed stream can comprise hydrogen in an amount of at least 0.1 volume percent (vol %) up to 20 vol % based upon total volume of the feed stream.