Low Temperature Direct Air Capture Using Sweep Gas Desorption
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Solution Overview
Problem
Current carbon capture and regeneration technologies require significant temperature swings, leading to high energy costs and sorbent degradation due to high regeneration temperatures.
Innovation Solution
The method involves heating a sweep liquid to a low temperature (85°C or less) to form a sweep gas, which is then used to desorb CO2 from a sorbent bed at a low pressure (90 kPa-a or less) and temperature (70°C or less), followed by a multi-stage separation process to recover the sweep gas and enhance CO2 purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high regeneration temperatures are used, then desorption efficiency is improved, but energy consumption increases and sorbent degradation occurs
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (80-480°C) to low temperatures (25-70°C) for regeneration, fundamentally altering the operating conditions to reduce energy consumption while maintaining desorption efficiency through optimized sorbent selection and process design
Solution Approach 2:
The patent utilizes phase transition phenomena, including vapor-liquid equilibrium and condensation, to enable efficient desorption at low temperatures by controlling the phase behavior of the sorbent-sweep gas system, allowing regeneration without high temperature heating
2Productivity
If high regeneration temperatures are used, then desorption efficiency is improved, but sorbent degradation increases
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (80-480°C) to low temperatures (25-70°C) for regeneration, fundamentally altering the operating conditions to reduce energy consumption while maintaining desorption efficiency through optimized sorbent selection and process design
Solution Approach 2:
The patent converts the typically harmful effect of high temperatures into a beneficial low-temperature process by selecting sorbents that are specifically designed to operate at reduced temperatures, thereby protecting the sorbent from thermal degradation while maintaining functionality
3Power
If steam is used for heating, then heat transfer efficiency is improved, but energy cost increases
Solution Approach 1:
The patent introduces a sweep gas as an intermediary medium that facilitates heat transfer and mass transfer during regeneration, replacing the need for high-temperature steam heating and reducing energy costs while maintaining effective heat transfer
Solution Approach 2:
The patent substitutes the mechanical/thermal heating system using steam with a chemical/mass transfer-based regeneration system using sweep gas, fundamentally changing the mechanism of regeneration to reduce energy consumption
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 energy consumption, minimizes sorbent degradation, and enables efficient recovery of sweep gases, thereby improving the overall efficiency and cost-effectiveness of carbon capture processes.
Implementation Method 1
heating a sweep liquid to a first temperature to form a sweep gas
Implementation Method 2
exposing a sorbent bed in a sorbent environment to at least a portion of the sweep gas
Implementation Method 3
reducing the temperature of at least a portion of the desorption effluent to a temperature below the first temperature to form a first intermediate effluent enriched in the at least one desorbed component and a first condensed sweep liquid
Data Source
AI summary
Systems and methods are provided for low temperature separation of sweep gas from desorbed components. This can allow for performance of sorption/desorption cycles at reduced temperatures and/or pressures. Methanol is an example of a sweep gas that can be used for desorption at reduced temperatures. CO2 is an example of a component that can be sorbed and desorbed using a sorption/desorption cycle with reduced temperatures and/or pressures.