Potassium Thiosulfate Oxidation Process for High Purity
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Solution Overview
Problem
Current methods for producing potassium thiosulfate face challenges such as long processes, use of sulfur dioxide, handling of hydrogen sulfide environments, and high costs due to expensive raw materials and equipment, resulting in products with high impurity levels and poor storage stability.
Innovation Solution
A process involving the oxidation of potassium polysulfide using potassium hydroxide and sulfur under controlled temperature and pressure conditions with an oxidizing agent like oxygen, optimizing mole ratios and reaction times to produce high-purity potassium thiosulfate with minimal byproducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional routes (I-V) are used to produce potassium thiosulfate, then the production process can be completed, but the processes are long, require expensive raw materials and equipment, and produce high impurity levels
Solution Approach 1:
The patent changes the chemical parameters of the reaction system by using potassium polysulfide as the starting material instead of conventional routes. The oxidation process uses controlled oxygenation with specific pH ranges (9-11) and temperature conditions to directly produce high-purity potassium thiosulfate, avoiding the complex multi-step processes and expensive equipment required by conventional methods
Solution Approach 2:
The patent extracts and eliminates the problematic intermediate steps and byproduct formation stages present in conventional routes. By starting with potassium polysulfide and applying controlled oxidation, the process directly produces potassium thiosulfate with minimal impurities, removing the need for extensive purification steps and complex equipment
2Productivity
If Route VI is used to produce potassium thiosulfate, then production can be achieved, but the product has high levels of impurities and poor storage stability
Solution Approach 1:
The patent applies controlled oxidation using oxygen as the oxidizing agent under specific conditions (pH 9-11, controlled temperature) to efficiently convert potassium polysulfide to potassium thiosulfate. This accelerated oxidation process achieves high productivity while maintaining product purity and stability by preventing over-oxidation to sulfates and minimizing impurity formation
3Adaptability or versatility
If thiosulfates are produced by conventional methods, then they can be used as fertilizers, but they readily oxidize to dithionates, trithionates, tetrathionates, and finally to sulfates reducing storage stability
Solution Approach 1:
The patent optimizes the chemical parameters of the production process, specifically maintaining pH in the range of 9-11 during oxidation and controlling temperature conditions. These parameter changes produce potassium thiosulfate with enhanced stability characteristics, reducing its tendency to oxidize further to dithionates, trithionates, tetrathionates, and sulfates, thereby improving storage stability while maintaining its effectiveness as a fertilizer
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 yields a high-concentration potassium thiosulfate solution with low solid or soluble byproducts, suitable for use as a liquid fertilizer, offering improved stability and reduced production costs.
Implementation Method 1
adding an oxidizing agent, preferably oxygen, to the reaction mixture and reacting under conditions suitable to form potassium thiosulfate
Implementation Method 2
The process for the preparation of potassium thiosulfate from potassium polysulfide by oxidation
Data Source
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AI summary
An efficient process for preparation of potassium thiosulfate (K2S2O3) is described. Potassium hydroxide (KOH) and elemental sulfur (S) are converted to potassium polysulfide, which is subsequently oxidized. The process allows using specifically designed process conditions such as mole ratios of potassium hydroxide to sulfur, and temperature, to obtain an optimized formulation of desired polysulfide, and a specifically designed set of conditions such as temperature, pressure, rate and duration of the oxidant during the oxidation conditions, to obtain a relatively high concentration of soluble potassium thiosulfate product with high purity, with relatively low amounts of byproducts. The manufacturing process can either be a batch process or a continuous process utilizing Continuous Stirred Tank Reactors (CSTR). The CSTR process is dependent on several design parameters, including pressure, and temperature optimization to avoid product instability. The resulting potassium thiosulfate is a beneficial fertilizer with high potassium content as a 50% liquid source of potassium.