Formic Acid Production Vessel Oxygen Pressure Segmentation
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Solution Overview
Problem
The high oxygen partial pressure and temperature in existing methods for catalytic formic acid production cause severe corrosion of steel pressure vessels, making the process expensive due to the need for highly corrosion-resistant materials like nickel-chromium-molybdenum alloys.
Innovation Solution
The process is modified to operate at an oxygen partial pressure below 1 bar, allowing the use of less expensive vessel materials, such as plastic, by cooling and exposing the liquid solution to increased oxygen pressure in a separate, smaller vessel, which reduces corrosion and eliminates the need for high-pressure resistance in the primary reaction vessel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the process is carried out at high oxygen partial pressure (1 to 500 bar) to accelerate catalyst oxidation, then the oxidation speed of the reduced catalyst is improved, but severe corrosion of steel pressure vessels occurs
Solution Approach 1:
The process is divided into two separate spatial locations: a reaction vessel where formic acid is produced at low oxygen partial pressure, and a separate oxidation unit where catalyst regeneration occurs at high oxygen partial pressure. This segmentation allows each unit to operate under optimal conditions without the harmful effects combining in one system.
Solution Approach 2:
The high-oxygen partial pressure oxidation step is extracted from the main reaction vessel and performed in a separate unit. Only the necessary liquid solution (containing reduced catalyst) is transferred for oxidation, while the bulk reaction mixture remains in the original vessel at low oxygen pressure, preventing corrosion during the main production process.
2Reliability
If highly corrosion-resistant nickel-chromium-molybdenum alloys are used to prevent vessel corrosion, then the vessel corrosion resistance is improved, but the process cost increases significantly
Solution Approach 1:
The system is segmented such that only a small oxidation unit (processing small volumes of liquid solution) requires high corrosion resistance, while the main reaction vessel can use inexpensive materials. This dramatically reduces the total amount of expensive material needed.
Solution Approach 2:
The oxidation unit, which operates under severe corrosive conditions, is designed as a small, replaceable component. Since it handles only small amounts of liquid and can be easily replaced, using expensive corrosion-resistant material only for this small unit is economically justified rather than protecting the entire large reaction vessel.
3Ease of manufacture
If the oxygen partial pressure in the main reaction vessel is kept below 1 bar to avoid corrosion, then the vessel material cost is reduced, but the catalyst oxidation efficiency decreases
Solution Approach 1:
The catalyst oxidation function is extracted from the main reaction vessel and performed in a separate dedicated oxidation unit where high oxygen partial pressure can be applied efficiently. The main vessel maintains low oxygen pressure for cost-effective construction, while the extracted oxidation unit handles the efficiency-critical step under optimal conditions.
Solution Approach 2:
A small intermediate transfer step is introduced where reduced catalyst-containing liquid solution is temporarily moved to an oxidation unit, exposed to high oxygen partial pressure, and then returned to the main vessel. This intermediary step enables efficient catalyst regeneration without requiring the main reaction vessel to operate under corrosive high-oxygen conditions.
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 significantly reduces material costs and prevents vessel corrosion, enabling the catalytic production of formic acid at a lower cost while maintaining catalyst effectiveness and longevity.
Implementation Method 1
The process is modified to operate at an oxygen partial pressure below 1 bar, allowing the use of less expensive vessel materials, such as plastic, by cooling and exposing the liquid solution to increased oxygen pressure in a separate, smaller vessel
Implementation Method 2
The catalyst reduced in the reaction to form formic acid is restored to its original state by oxidation
Implementation Method 3
the oxygen partial pressure acting on the part of the liquid solution is reduced from 1 to 500 bar to a value below 5 bar, in particular below 1 bar, before the part of the liquid solution is fed back into the rest of the liquid solution
Data Source
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AI summary
The invention relates to a method for the catalytic generation of formic acid at an oxygen partial pressure below 1 bar and regeneration of the catalyst used therefor, wherein a polyoxometalate-ion, serving as a catalyst, of general formula [PMoxVyO40]n- at a temperature above 70°C and below 120°C is brought into contact with an alpha-hydroxy aldehyde, an alpha-hydroxycarboxylic acid, a carbohydrate, a glycoside or a polymer containing a carbon chain with at least one OH-group joined to the carbon chain repeatedly as a substituent and/or with an O-, N- or S-atom contained repeatedly in the carbon chain, in a liquid solution (12) in a vessel (10), wherein 6 ≤ x ≤ 11 and 1 ≤ y ≤ 6 and 3 < n < 10 and x + y = 12, wherein n, x and y are whole numbers, wherein the catalyst reduced in this way is converted back to its starting state by means of oxidation, wherein the contacting is carried out in the vessel (10) at an oxygen partial pressure below 1 bar, wherein, for the oxidation of the catalyst, a portion of the liquid solution (12) is discharged from the vessel (10), supplied with oxygen or a gas mixture containing oxygen at an oxygen partial pressure of 1 to 500 bar, and subsequently fed back to the rest of the liquid solution (12), wherein the oxygen partial pressure in the vessel is constantly maintained below 1 bar, wherein the oxygen partial pressure of 1 to 500 bar being applied to the portion of the liquid solution (12) is reduced to below 5 bar, before the portion of the liquid solution (12) is fed back to the rest of the liquid solution (12).