Monoalkanolamine Production via Low-Pressure Flash Drum Separation
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Solution Overview
Problem
Current methods for producing mono-lower-alkyl monoalkanolamine, such as the zeolite catalyst method and supercritical method, face issues with high energy consumption, increased production and wastewater treatment costs, and the need for additional disposal costs for by-products, especially when mass-producing this compound.
Innovation Solution
A method and apparatus utilizing a water catalyst method with a reaction column, distillation column, and flash drum to separate unreacted raw materials and by-products, allowing for reduced production and wastewater treatment costs by simplifying the separation of mono-lower-alkyl monoalkanolamine in a gas state at operating temperatures between 110 to 200°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the zeolite catalyst method is used to produce mono-lower-alkyl monoalkanolamine, then the reaction selectivity is improved, but the energy consumption increases due to the need for a chiller in the condenser
Solution Approach 1:
The invention changes the operating parameters of the distillation column, specifically operating at a pressure of 0.01 to 0.2 MPa (preferably 0.02 to 0.1 MPa) which allows the condenser to function without a chiller. This pressure parameter change enables condensation at higher temperatures, eliminating the need for refrigeration while maintaining separation efficiency.
Solution Approach 2:
The invention extracts and removes the chiller component from the system by operating the distillation column at reduced pressure, allowing natural condensation to occur without active refrigeration. This eliminates the energy-consuming cooling system while preserving the zeolite catalyst method's selectivity advantages.
2Productivity
If the supercritical method is used to produce mono-lower-alkyl monoalkanolamine, then the reaction efficiency is improved, but the power consumption and operation cost increase due to high temperature and pressure requirements
Solution Approach 1:
The invention changes the pressure parameter of the distillation column to 0.01 to 0.2 MPa, which is significantly lower than the supercritical method's 17 to 24 MPa requirement. This parameter change allows the process to achieve good separation efficiency without the extreme pressures and temperatures that cause high power consumption.
3Manufacturing precision
If the water catalyst method is used to improve the yield of mono-lower-alkyl monoalkanolamine, then the selectivity is improved, but the reboiler load increases and wastewater treatment cost increases
Solution Approach 1:
The invention changes the operating pressure of the distillation column to 0.01 to 0.2 MPa, which optimizes the vapor-liquid equilibrium and improves separation efficiency. This reduces the number of theoretical plates needed and lowers the reboiler load while maintaining high selectivity. The reduced pressure operation also minimizes water generation that requires treatment.
4Productivity
If mass production of mono-lower-alkyl monoalkanolamine is performed using conventional methods, then the production scale is increased, but the production cost increases due to additional disposal costs for by-products
Solution Approach 1:
The invention converts the harmful by-product (dimer) into a beneficial outcome by using it as a solvent in the reaction system. This eliminates the need for separate disposal processes and reduces production costs. The dimer's presence in the reaction mixture actually helps dissolve reactants and products, improving reaction efficiency while enabling mass production without increased disposal costs.
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 reduces production costs and wastewater treatment costs by simplifying the separation of by-products and eliminating the need for active water separation, enhancing cost efficiency in mass production.
Implementation Method 1
separating the mono-lower-alkyl monoalkanolamine in a gas state in a flash drum at an operating temperature in a range of 110 to 200°C
Implementation Method 2
removing an unreacted raw material by distillation
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A reaction column (12) to which a raw material mixture (11) containing a mono-lower-alkylamine (AA: raw material I) and an alkylene oxide (AO: raw material II) is supplied, an unreacted raw material distillation column (14) that separates an unreacted raw material (15) from a reaction product (13a) (containing the unreacted raw material (15), a target reaction product (monomer) (17), and a by-product (dimer) (18)), and a flash drum (16) to which a reaction product (13b) (containing the target reaction product (monomer) (17) and the by-product (dimer) (18)) is supplied, the flash drum (16) separating a mono-lower-alkyl monoalkanolamine (monomer, the target reaction product 17) in a gas state, are provided.