Mixed Oxide Catalyst Ethane Selective Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for oxidizing ethane to ethylene suffer from low selectivity and productivity due to high reaction pressures and restrictive temperature conditions, limiting their commercial viability.
Innovation Solution
A mixed oxide catalyst with the formula Mo a V v Ta x Te y, specifically Mo 1.0 V 0.3 Ta 0.1 Te 0.3 O z, is used to oxidize ethane to ethylene under mild conditions, achieving high selectivity and space-time yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing oxidative dehydrogenation methods are used at temperatures above 500°C, then ethylene can be produced, but selectivity is low and deep oxidation products increase
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (>500°C) to mild temperatures (200-400°C), and modifies the catalyst composition parameters by using a specific mixed oxide system with Mo, V, Nb, and Sb in optimized ratios. This parameter change resolves the contradiction by enabling high ethylene selectivity (76-80%) at lower temperatures where deep oxidation is minimized.
Solution Approach 2:
The patent employs a composite catalyst material consisting of multiple metal oxides (Mo, V, Nb, Sb) combined in specific proportions. This composite catalyst system works synergistically to achieve high ethylene selectivity while suppressing deep oxidation reactions, resolving the contradiction between productivity and selectivity that plagues single-catalyst systems.
2Productivity
If reaction pressure is increased to improve productivity, then space-time yield increases, but selectivity decreases and commercial viability is limited
Solution Approach 1:
The patent optimizes the pressure parameter by operating at moderate pressures (1-10 atm) rather than extremely low pressures or high pressures. Combined with optimized temperature and catalyst composition parameters, this enables the system to achieve both high productivity (space-time yield up to 460 kg/m³h) and high selectivity (76-80%), resolving the contradiction between these two parameters.
3Productivity
If reaction temperature is increased above 500°C to improve conversion rate, then ethane conversion increases, but selectivity for ethylene decreases
Solution Approach 1:
The patent fundamentally changes the temperature parameter from conventional high temperatures (>500°C) to mild temperatures (200-400°C). This parameter change, combined with the optimized mixed oxide catalyst, enables the system to achieve high ethane conversion rates while maintaining ethylene selectivity above 76%, effectively resolving the contradiction between conversion rate and selectivity.
Solution Approach 2:
The patent replaces the conventional thermal mechanism (relying on high temperature to drive conversion) with a catalytic mechanism using the mixed oxide system. This substitution allows the reaction to proceed at lower temperatures with high conversion rates, eliminating the need to compromise selectivity for conversion.
4Manufacturing precision
If reaction pressure is maintained at very low levels (1 atm) as in existing methods, then selectivity is maintained, but productivity and commercial viability are restricted
Solution Approach 1:
The patent optimizes the pressure parameter by operating at moderate pressures (1-10 atm) rather than extremely low pressures. This parameter change, combined with the optimized catalyst system and temperature conditions, enables the simultaneous achievement of high selectivity (76-80%) and high productivity (space-time yield up to 460 kg/m³h), resolving the contradiction between these two parameters.
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 catalyst enables high selectivity (up to 80%) and productivity of ethylene while minimizing deep oxidation products, significantly improving upon previous methods by operating at lower pressures and temperatures.
Implementation Method 1
A mixed oxide catalyst with the formula Mo a V v Ta x Te y, specifically Mo 1.0 V 0.3 Ta 0.1 Te 0.3 O z, is used to oxidize ethane to ethylene under mild conditions, achieving high selectivity and space-time yields.
Implementation Method 2
The catalyst enables high selectivity (up to 80%) and productivity of ethylene while minimizing deep oxidation products, significantly improving upon previous methods by operating at lower pressures and temperatures.
Data Source
AI summary
A process is disclosed for selectively preparing ethylene by oxidizing ethane in the presence of oxygen using a catalyst having the formula MoaVvTaxTey. Preferably a is 1.0; v is about 0.01 to about 1.0; x is about 0.01 to about 1.0; and y is about 0.01 to about 1.0.