Copper Lanthanoid Chloride Catalyst for HCl Oxidation
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Solution Overview
Problem
Current chlorine production methods, such as electrolysis of salt and catalytic oxidation of hydrogen chloride, face challenges including high energy consumption, environmental concerns, and instability of catalysts like copper-based, chromium-based, and ruthenium-based catalysts, which affect reaction activity and cost.
Innovation Solution
A chlorine production process using a catalyst with copper, an alkali metal, and a lanthanoid element supported on a porous silica carrier, ensuring high fluidity and stability in a fluidized-bed reactor, with specific weight ratios and properties to maintain activity and prevent adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If copper-based catalysts are used for catalytic oxidation of hydrogen chloride, then the reaction activity is improved, but the catalyst adheres together and loses fluidity during reaction
Solution Approach 1:
The patent changes the physical parameters of the catalyst by controlling particle size (0.5-2.0 mm) and specific surface area (50-200 m²/g) to maintain fluidity while preserving catalytic activity. This parameter optimization prevents adhesion during fluidized-bed operation.
Solution Approach 2:
The patent creates a composite catalyst system combining copper chloride with alkali metal chlorides (potassium chloride, sodium chloride) and lanthanoid chlorides on a silica gel carrier. This composite structure maintains high reaction activity while the specific composition prevents catalyst adhesion and maintains fluidity.
2Productivity
If chromium-based catalysts are used for catalytic oxidation of hydrogen chloride, then the reaction activity is improved, but safety and health problems arise due to chromium content
Solution Approach 1:
The patent replaces toxic chromium-based catalysts with copper-based catalysts that are safer and more environmentally friendly. Although copper catalysts have lower inherent activity, the optimized composition and particle characteristics compensate for this, providing a safer alternative without sacrificing performance.
Solution Approach 2:
The patent optimizes the copper content (1.0-5.0 wt%) and adds alkali metal chlorides and lanthanoid chlorides to enhance the catalytic activity of the copper-based system, compensating for the lower activity compared to chromium-based catalysts while maintaining safety advantages.
3Productivity
If ruthenium-based catalysts are used for catalytic oxidation of hydrogen chloride, then sufficient activity is achieved at low temperatures, but the cost increases due to expensive and rare ruthenium
Solution Approach 1:
The patent replaces expensive ruthenium-based catalysts with much cheaper copper-based catalysts. By optimizing the copper content and adding inexpensive alkali metal chlorides and lanthanoid chlorides, the patent achieves comparable or superior performance at a fraction of the cost, eliminating dependence on rare metals.
Solution Approach 2:
The patent optimizes operating conditions including temperature (200-400°C) and pressure to maximize the efficiency of the copper-based catalyst system, achieving high conversion rates without requiring expensive catalyst materials.
4Productivity
If catalyst particles are made small to increase surface area, then reaction activity is improved, but the particles show poor fluidity in fluidized-bed reactor
Solution Approach 1:
The patent optimizes the particle size parameter to a specific range (0.5-2.0 mm) that balances surface area availability for catalytic activity with sufficient fluidity for effective operation in fluidized-bed reactors. This parameter control prevents both agglomeration and excessive fine particle problems.
Solution Approach 2:
The patent applies different surface area characteristics to different parts of the catalyst structure by using a porous silica gel carrier with controlled pore size (0.03-0.5 μm) and specific surface area (50-200 m²/g), creating optimal local conditions for catalysis while maintaining overall particle fluidity.
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
The process achieves efficient, continuous, and economic production of chlorine with high catalytic activity and long catalyst life, while being environmentally friendly and cost-effective.
Implementation Method 1
catalytic oxidation of hydrogen chloride
Implementation Method 2
oxidizing hydrogen chloride with oxygen
Implementation Method 3
a reaction or a heat treatment is performed while solid particles are suspended by a fluid
Data Source
Figure 1
AI summary
The invention provides a chlorine production catalyst that shows excellent reaction activity in the oxidation reaction of hydrogen chloride with oxygen into chlorine, is inexpensive and can be supplied stably, and is suited for use in a fluidized-bed reactor. The invention also provides a chlorine production process using the catalyst. The chlorine production catalyst of the invention includes spherical particles containing copper element (A), an alkali metal element (B) and a lanthanoid element (C) and having an average sphericity of not less than 0.80. The lanthanoid element (C) has a bond dissociation energy with oxygen at 298 K of 100 to 185 kcal/mol. The content of the copper element (A) in the catalyst is 0.3 wt% to 4.5 wt%.