Aqueous Biphasic Solvent Compositions for Low-Energy CO2 Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current post-combustion carbon capture (PCC) technologies are energy intensive and expensive, with monoethanolamine (MEA) processes consuming nearly 30% of a coal-fired power plant's electricity output and facing high solvent viscosity and volatility issues in biphasic solvents, limiting their industrial application.
Innovation Solution
Development of aqueous compositions comprising sterically unhindered amines, Brønsted bases, and water-soluble organic solvents that form biphasic mixtures with miscibility within a specific temperature range, reducing solvent viscosity and volatility, and enabling efficient carbon dioxide capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If biphasic solvents are used to reduce the mass of solvent required for thermal regeneration, then energy use and equipment footprint are reduced, but the high viscosity of the CO2-rich liquid phase causes low heat transfer and mass transfer rates, increasing process costs
Solution Approach 1:
The patent modifies the physical and chemical parameters of the biphasic solvent system by adjusting solvent composition, temperature, and pressure conditions to optimize the balance between phase separation extent and viscosity. This allows the system to maintain low viscosity while achieving sufficient phase separation for reduced regeneration energy
Solution Approach 2:
The patent employs composite solvent formulations combining multiple amine components with specific properties to create a biphasic system that achieves both low viscosity and effective CO2 separation. The composite nature of the solvent allows optimization of both heat transfer properties and phase separation behavior
2Quantity of substance
If the extent of phasic separation is increased to concentrate CO2 in a smaller volume, then the mass of solvent for regeneration is reduced, but the viscosity of the CO2-rich liquid phase increases significantly
Solution Approach 1:
The patent controls the extent of phase separation by adjusting operational parameters such as temperature, pressure, and solvent composition to achieve an optimal separation level that concentrates CO2 sufficiently while preventing excessive viscosity increase in the CO2-rich phase
3Reliability
If conventional monophasic amine scrubbing is used to achieve reliable CO2 capture, then CO2 separation performance is maintained, but the process consumes nearly 30% of electricity output and incurs high operating costs
Solution Approach 1:
The patent divides the single-phase solvent system into two immiscible liquid phases, allowing CO2 to be selectively concentrated in one phase. This segmentation enables the system to achieve effective CO2 capture while reducing the total amount of solvent that requires thermal regeneration, thereby lowering energy consumption
Solution Approach 2:
The patent utilizes liquid-liquid phase separation as a transition mechanism to divide the solvent system into CO2-rich and CO2-lean phases. This phase transition allows for more efficient CO2 loading and reduces the energy required for solvent regeneration compared to conventional monophasic systems
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 new compositions achieve reduced energy consumption and solvent loss, maintaining high carbon dioxide capture performance with lower equipment costs and environmental impact.
Implementation Method 1
the nucleophilic compound and carbon dioxide gas form a carbamate moiety via the nitrogen atom of the primary or secondary amine moiety
Implementation Method 2
biphasic solvents that can undergo a liquid-liquid phase separation after the loading of CO2 with the absorbed CO2 enriched in one liquid phase and lean in the other
Data Source
AI summary
An aqueous solvent composition is provided, comprising a nucleophilic component having one or more sterically unhindered primary or secondary amine moieties, a Brønsted base component having one or more basic nitrogen moieties, a water-soluble organic solvent, and water. A biphasic composition is provided, comprising one or more carbamate compounds, one or more conjugate acids of Brønsted base, a water-soluble organic solvent, and water. A biphasic CO2 absorption process is also provided, utilizing the biphasic solvent composition.