Amine Absorbent Composition for Low-Viscosity CO2 Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional amine-based absorbents for capturing carbon dioxide suffer from low cyclic capacity, crystallization at low temperatures, and high viscosity, leading to inefficient gas-liquid exchange and increased energy consumption in carbon capture systems.
Innovation Solution
An absorbent comprising methyldiethanolamine (MDEA) and piperazine in specific concentration ratios, along with monoethanolamine (MEA), prevents crystallization and maintains low viscosity, enhancing cyclic capacity and absorption rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional amine-based absorbents are used for CO2 capture, then CO2 absorption efficiency is achieved (75%-90%), but cyclic capacity is low and CO2 desorption in regeneration is inefficient
Solution Approach 1:
The patent uses a composite absorbent system combining three amine components: MEA (monoethanolamine) providing fast reaction kinetics, MDEA (methyldiethanolamine) providing high cyclic capacity through selective CO2 binding, and piperazine enhancing absorption rate. This composite approach allows the system to achieve both high absorption efficiency and excellent regeneration performance, with cyclic capacity up to 0.5 mol/L reported in the patent.
2Quantity of substance
If absorbent concentration is increased to improve absorption capacity, then CO2 uptake increases, but viscosity increases and gas-liquid exchange efficiency decreases
Solution Approach 1:
The patent optimizes the concentration parameters of each amine component to achieve the desired balance. Specifically, it uses MEA at 5-20 wt%, MDEA at 10-30 wt%, and piperazine at 5-15 wt%, with the sum of all amine components being 20-60 wt%. This parameter optimization ensures sufficient CO2 absorption capacity while maintaining viscosity at levels that allow efficient gas-liquid exchange in the absorption column.
3Productivity
If absorbent is supplied at low temperatures to improve CO2 absorption, then absorption efficiency increases, but crystallization occurs and normal absorption becomes infeasible
Solution Approach 1:
The patent adjusts the compositional parameters of the absorbent to prevent crystallization at low operating temperatures. The specific formulation with MEA (5-20 wt%), MDEA (10-30 wt%), and piperazine (5-15 wt%) creates a eutectic mixture that remains liquid at temperatures as low as 0°C, allowing efficient CO2 absorption to proceed without crystallization issues.
4Quantity of substance
If high amine concentration is used to enhance absorption capacity, then CO2 uptake improves, but regeneration energy consumption increases
Solution Approach 1:
The patent assigns different functional roles to each amine component to optimize the overall system performance. MDEA (10-30 wt%) provides selective CO2 binding with lower heat of reaction, requiring less energy for regeneration. MEA (5-20 wt%) provides fast reaction kinetics for high absorption capacity. Piperazine (5-15 wt%) enhances the absorption rate. This functional differentiation allows the system to achieve high absorption capacity while maintaining reasonable regeneration energy requirements.
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
The absorbent achieves high CO2 absorption rates and cyclic capacity while preventing crystallization at low temperatures, facilitating efficient gas-liquid exchange and reducing regeneration energy consumption.
Implementation Method 1
chemical absorption method that absorbs and captures CO2 using an absorbent solution has been the most widely applied
Implementation Method 2
The reaction between CO2 and the absorbent occurring in the absorption part 91 is an exothermic reaction
Implementation Method 3
the CO2-containing absorbent may be regenerated through expansion under low pressure and/or thermal stripping
Implementation Method 4
the desorption of CO2 occurring in the regeneration part is an endothermic reaction
Implementation Method 5
the absorbent is an aqueous mixture having a eutectic composition, the absorbent prevents crystallization of the absorbent at low temperatures
Implementation Method 6
ensuring efficient gas-liquid exchange within an absorption part and a regeneration part
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to an absorbent for capturing carbon dioxide and, more specifically, to an absorbent for capturing carbon dioxide, comprising: a liquid amine-based compound; a solid amine-based compound; and water, wherein the liquid amine-based compound comprises monoethanolamine and methyldiethanolamine, and the solid amine-based compound is piperazine. The absorbent has an excellent absorption rate and cyclic capacity as a result of the composition ratio having concentrations of piperazine and methyldiethanolamine within a predetermined range, and at the same time, the crystal formation of a fresh absorbent in room-temperature and low-temperature environments is prevented, and the absorbent facilitates gas-liquid exchange in an absorption part and a regeneration part due to the reduced viscosity thereof.