Ethane Oxidative Dehydrogenation Process with CO Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxidative dehydrogenation (ODH) of ethane to ethylene faces challenges such as lower conversion rates, selectivity, and the risk of thermal explosions due to hydrocarbon-oxygen mixing, while also producing carbon monoxide, which acts as a catalyst poison in vinyl acetate production, and high carbon dioxide output.
Innovation Solution
The process involves converting ethane to ethylene using ODH with a catalyst, followed by a CO Oxidation Reactor to convert carbon monoxide to carbon dioxide, and then using the ethylene and acetic acid to produce vinyl acetate, with controlled carbon dioxide output and minimal carbon monoxide levels to prevent catalyst poisoning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam cracking is used to produce ethylene, then high conversion rates are achieved, but high energy consumption and equipment cost increase
Solution Approach 1:
The patent changes the fundamental reaction parameters by switching from high-temperature steam cracking (800°C+) to low-temperature oxidative dehydrogenation (200-400°C). This parameter change reduces energy consumption while maintaining ethylene production, directly resolving the contradiction between conversion rate and energy use
2Productivity
If steam cracking is used to produce ethylene, then high conversion rates are achieved, but equipment cost increases due to high temperature requirements
Solution Approach 1:
The patent reduces the operating temperature parameter from 800°C+ to 200-400°C, which allows use of less expensive equipment that cannot withstand extreme temperatures. The oxidative dehydrogenation process achieves good conversion rates at these lower temperatures, resolving the contradiction between productivity and equipment cost
3Productivity
If steam cracking is used to produce ethylene, then high conversion rates are achieved, but coke formation increases requiring periodic maintenance
Solution Approach 1:
The patent changes the temperature parameter from high (800°C+) to low (200-400°C), which fundamentally reduces coke formation. The oxidative dehydrogenation process at lower temperatures produces minimal coke, eliminating the need for periodic reactor shutdowns for maintenance while maintaining good conversion rates
4Use of energy by moving object
If oxidative dehydrogenation is used to produce ethylene, then lower energy consumption is achieved, but conversion rates decrease
Solution Approach 1:
The patent introduces oxygen as an intermediary substance that enables oxidative dehydrogenation. This intermediary allows the reaction to proceed at lower temperatures with improved conversion rates compared to traditional low-energy methods, resolving the contradiction between energy consumption and productivity
5Device complexity
If oxidative dehydrogenation is used to produce ethylene, then lower equipment cost is achieved, but conversion rates and selectivity decrease
Solution Approach 1:
The patent uses oxygen as an intermediary to enable oxidative dehydrogenation at low temperatures. This approach achieves good conversion rates and selectivity (comparable to or better than steam cracking) while using less expensive equipment, resolving the contradiction between equipment cost and productivity
6Reliability
If carbon monoxide is present in vinyl acetate production, then catalyst poisoning occurs, but no effective removal method is disclosed
Solution Approach 1:
The patent extracts and removes carbon monoxide from the reaction stream using a dedicated CO oxidation reactor. This extraction eliminates the harmful effect of CO catalyst poisoning while maintaining vinyl acetate production, directly resolving the contradiction between catalyst reliability and harmful factors
7Productivity
If hydrocarbon and oxygen are mixed for oxidative dehydrogenation, then ethylene production is enabled, but risk of thermal explosion increases
Solution Approach 1:
The patent changes the temperature parameter to a lower range (200-400°C) and controls the oxygen-to-hydrocarbon ratio to remain below stoichiometric levels. These parameter changes enable oxidative dehydrogenation to proceed safely without thermal explosion while maintaining ethylene production capability
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 enhances ethylene production efficiency, reduces catalyst poisoning, and optimizes carbon dioxide output, improving the overall process selectivity and safety by converting carbon monoxide to carbon dioxide, thus addressing the limitations of ODH and enabling efficient vinyl acetate production.
Implementation Method 1
In ODH a lower alkane, such as ethane, is mixed with oxygen in the presence of a catalyst and optionally an inert diluent
Implementation Method 2
Oxidative dehydrogenation (ODH) is an alternative to steam cracking that is exothermic and produces little or no coke
Implementation Method 3
a CO Oxidation Reactor to convert carbon monoxide to carbon dioxide
Implementation Method 4
subsequent reaction of at least a portion of the ethylene with acetic acid to provide vinyl acetate monomer
Data Source
AI summary
A method that includes (a) providing a stream containing ethane and oxygen to an ODH reactor; (b) converting a portion of the ethane to ethylene and acetic acid in the ODH reactor to provide a stream containing ethane, ethylene, acetic acid, oxygen and carbon monoxide; (c) separating a portion of the acetic acid from the stream to provide an acetic acid stream and a stream containing ethane, ethylene, oxygen and carbon monoxide; (d) providing the stream to a CO Oxidation Reactor containing a catalyst that includes a group 11 metal to convert carbon monoxide to carbon dioxide and reacting acetylene to produce a stream containing ethane, ethylene and carbon dioxide; and (e) providing a portion of the stream and a portion of the acetic acid stream to a third reactor containing a catalyst that includes a metal selected from group 10 and group 11 metals to produce vinyl acetate.