Epichlorohydrin Production Using Renewable Glycerol
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Solution Overview
Problem
Current processes for producing dichloropropanol consume significant natural petrochemical resources and result in highly diluted solutions, making purification expensive and inefficient, with a preference for the major isomer 2,3-dichloropropane-1-ol over 1,3-dichloropropane-2-ol, which is less suitable for dehydrochlorination to produce epichlorohydrin.
Innovation Solution
The use of glycerol obtained from renewable raw materials, such as biodiesel production or animal fat conversion, as a starting material for producing dichloropropanol, where glycerol is purified or used in crude form with impurities, and reacted with a chlorinating agent like hydrogen chloride in the presence of a catalyst to produce dichloropropanol with high selectivity for 1,3-dichloropropane-2-ol, reducing resource consumption and purification costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If glycerol from renewable raw materials is used as starting material, then resource sustainability is improved, but production cost may increase due to purification requirements
Solution Approach 1:
The patent changes the chemical parameters of the reaction system by using glycerol from renewable raw materials with specific impurity profiles (metal salts, organic compounds, water) and optimizing reaction conditions (temperature 80-150°C, catalyst selection) to achieve high selectivity for 1,3-dichloropropan-2-ol while managing purification costs through controlled impurity levels
Solution Approach 2:
The patent recovers and reuses by-products from the process, particularly hydrogen chloride generated during dehydrochlorination, which is fed back into the chlorination step. This closes material loops and reduces both resource consumption and waste treatment costs, addressing the economic concern of using renewable glycerol
2Manufacturing precision
If purification of crude glycerol is performed, then product quality is improved, but process complexity and cost increase
Solution Approach 1:
The patent applies partial purification to crude glycerol, removing only the most critical impurities (excessive water, major metal salt contaminants) while tolerating residual impurities that do not significantly affect the reaction. This selective approach achieves sufficient product quality without the complexity of complete purification, aligning with the principle of doing just enough to meet requirements
Solution Approach 2:
The reaction process itself serves as a purification step, where the chemical transformation and subsequent separation processes naturally remove many impurities. The product isolation steps (extraction, distillation) simultaneously purify both the desired product and remove glycerol-derived impurities, making the manufacturing process self-purifying to some extent
3Manufacturing precision
If 2,3-dichloropropane-1-ol is produced as major isomer, then reaction selectivity is improved, but suitability for epichlorohydrin production deteriorates
Solution Approach 1:
The patent inverts the conventional approach by deliberately targeting 1,3-dichloropropan-2-ol as the major isomer product instead of the traditionally preferred 2,3-dichloropropane-1-ol. This inversion is achieved through specific reaction conditions (temperature, catalyst, stoichiometry) that favor the formation of the 1,3-isomer, which then directly serves epichlorohydrin production without requiring isomer separation or conversion
4Ease of manufacture
If dichloropropanol is obtained in highly diluted solution, then reaction simplicity is improved, but purification cost and efficiency deteriorate
Solution Approach 1:
The patent utilizes phase transitions (extraction into organic phase, distillation) to concentrate dichloropropanol from the reaction mixture. The product is extracted into an organic solvent phase separate from the aqueous reaction medium, then concentrated through distillation or solvent removal, achieving high concentration suitable for downstream processing while managing energy requirements through efficient separation design
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 allows for the economical production of dichloropropanol and epichlorohydrin with high purity and selectivity, minimizing waste and resource usage, and enabling the valorization of by-products like hydrogen chloride, thus reducing environmental impact and operational costs.
Implementation Method 1
glycerol is purified or used in crude form with impurities, and reacted with a chlorinating agent like hydrogen chloride in the presence of a catalyst to produce dichloropropanol
Implementation Method 2
reacted with a chlorinating agent like hydrogen chloride in the presence of a catalyst to produce dichloropropanol with high selectivity
Data Source
AI summary
Process for producing epichlorohydrin comprising subjecting to a dehydrochlorination operation, dichloropropanol produced from glycerol comprising aldehydes.