Ethylene Recovery via Absorption Solvent in Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of polyethylene is hindered by high energy costs and capital expenses due to the need for multiple distillation columns and cryogenic temperatures to achieve high-purity feedstocks, and conventional processes for recycling unreacted ethylene are energetically unfavorable and costly.
Innovation Solution
A process involving the separation of polymerization product streams into gas and polymer streams, followed by distillation and absorption with a solvent system to recover unreacted ethylene, allowing for the recycling of ethylene and reducing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple distillation columns and cryogenic temperatures are used to purify feedstock, then high purity of monomers and comonomers is achieved, but energy costs and capital expenses increase significantly
Solution Approach 1:
The patent extracts and removes impurities from the feedstock stream using selective absorption solvents that specifically target and remove contaminants without requiring extensive distillation. This extraction approach achieves high purity with lower energy consumption by selectively removing harmful components rather than separating all components through energy-intensive distillation processes.
Solution Approach 2:
The patent changes the physical and chemical parameters of the purification process by using absorption solvents at moderate temperatures and pressures instead of cryogenic conditions. This parameter change allows for effective purification without the high energy costs associated with cooling feedstock to extremely low temperatures and maintaining multiple distillation columns.
2Loss of substance
If conventional purification processes are used to recover unreacted monomers, then monomer recovery is achieved, but the process becomes energetically unfavorable and expensive
Solution Approach 1:
The patent introduces an intermediary absorption solvent system that mediates the recovery of unreacted monomers from the polymerization product stream. This intermediary substance selectively absorbs unreacted monomers and impurities, allowing for their separation and recovery without requiring energy-intensive conventional purification processes. The solvent acts as a bridge between the crude product stream and the recovered monomers.
Solution Approach 2:
The patent changes the operational parameters of monomer recovery by conducting the absorption process at moderate temperatures and pressures rather than using cryogenic distillation. This parameter change makes the recovery process energetically favorable while still achieving effective separation and recovery of unreacted monomers for recycling.
3Manufacturing precision
If multiple distillation columns are operated to purify feedstock, then high purity is achieved, but infrastructure complexity and capital cost increase
Solution Approach 1:
The patent merges multiple separation functions into a single absorption step using a selective solvent system. Instead of requiring multiple distillation columns for different separation tasks, the absorption process combines impurity removal and monomer recovery in one integrated unit, significantly reducing infrastructure complexity and capital costs while maintaining high purity standards.
Solution Approach 2:
The patent extracts impurities and unreacted monomers from the feedstock and product streams using selective absorption, replacing the need for multiple distillation columns. This extraction approach achieves the required purity with a single, simpler processing unit, reducing both the number of equipment items and the overall infrastructure complexity.
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 process enhances the efficiency of polyethylene production by effectively recycling ethylene, thereby reducing energy costs and capital expenditures associated with feedstock purification.
Implementation Method 1
contacting the light hydrocarbon stream with an absorption solvent system, wherein at least a portion of the unreacted ethylene from the light hydrocarbon stream is absorbed by the absorption solvent system
Implementation Method 2
distilling the gas stream into a light hydrocarbon stream, wherein the light hydrocarbon stream comprises ethane and unreacted ethylene
Data Source
AI summary
A process for component separation in a polymer production system, comprising separating a polymerization product stream into a gas stream and a polymer stream, wherein the gas stream comprises ethane and unreacted ethylene, distilling the gas stream into a light hydrocarbon stream, wherein the light hydrocarbon stream comprises ethane and unreacted ethylene, contacting the light hydrocarbon stream with an absorption solvent system, wherein at least a portion of the unreacted ethylene from the light hydrocarbon stream is absorbed by the absorption solvent system, and recovering a waste gas stream from the absorption solvent system, wherein the waste gas stream comprises ethane, hydrogen, or combinations thereof.