Molten Borate CO2 Capture Using Boiler Heat Regeneration
Solution Overview
Problem
Existing methods for capturing carbon dioxide from industrial processes are inefficient, costly, and environmentally impactful, particularly due to the use of high volumes of steam or electrical energy for regenerating molten salts, and require significant modifications to existing systems.
Innovation Solution
A method and system utilizing heat generated within the industrial process to regenerate molten salts for carbon dioxide capture, minimizing external energy input by using a carbon capture system that integrates with high temperature systems, such as boilers, to absorb and desorb CO2 efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If steam is used as a sweep gas to regenerate molten salt in the desorber, then carbon dioxide can be recovered from the steam, but high volumes of superheated steam require re-design of the steam turbine and system modifications
Solution Approach 1:
The invention extracts and removes steam from the desorber system by directing the desorbed gas stream containing steam and CO2 to a separation unit where steam is condensed and removed, leaving high-purity CO2. This eliminates the need to pass high volumes of superheated steam through the steam turbine and avoids system redesign requirements.
Solution Approach 2:
The invention introduces a intermediate separation unit between the desorber and steam turbine that acts as a mediator. This unit condenses and separates steam from CO2, allowing the CO2 to be processed separately while the condensed steam can be returned to the boiler feed, thus avoiding direct passage of high-volume superheated steam through the turbine.
2Temperature
If fuel is combusted in high purity oxygen to achieve temperatures and heat required by the desorber to regenerate the molten salts, then the desorber can operate at required temperatures, but the method is inefficient and costly
Solution Approach 1:
The invention merges the desorber with the boiler system by positioning the desorber within the boiler chamber where it is heated by the combustion process. The desorber shares the thermal environment with the boiler, allowing it to reach required temperatures using the waste heat from combustion without requiring separate high-purity oxygen combustion equipment.
Solution Approach 2:
The combustion system serves multiple functions: it generates power through the steam turbine, produces steam for the industrial process, and simultaneously heats the desorber to regenerate molten salt. This multi-functionality eliminates the need for dedicated high-purity oxygen combustion equipment and improves overall energy efficiency.
3Reliability
If electrolysis is used to regenerate molten salts, then the molten salts can be regenerated, but large and prohibitive amounts of electrical energy are required
Solution Approach 1:
The invention replaces the electrolysis process (electrical/chemical method) with a thermal regeneration process. The desorber uses sensible heat from the boiler combustion to thermally decompose the molten salt and release CO2, eliminating the need for large amounts of electrical energy that would be required for electrolysis.
4Object-affected harmful factors
If traditional scrubbers are used to process CO2, then carbon emissions can be reduced, but the process is inefficient and resource intensive
Solution Approach 1:
The invention changes the operating parameters from conventional scrubbing conditions (aqueous solutions, ambient temperatures) to high-temperature molten salt conditions. The molten salt absorbs CO2 at elevated temperatures and releases it through thermal decomposition in the desorber, achieving high-purity CO2 recovery with improved efficiency and reduced resource consumption compared to traditional scrubbers.
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 and cost requirements while minimizing environmental impact, achieving high-purity CO2 capture with minimal steam content in the desorbed stream.
Implementation Method 1
contacting the gaseous stream with a first stream comprising a molten salt at an absorber, thereby absorbing CO2 from the gaseous stream into the first stream
Implementation Method 2
using the desorber, desorbing the absorbed CO2 from the second stream, thereby generating (i) a third stream comprising the molten salt and (ii) an export stream comprising CO2 desorbed from the second stream
Implementation Method 3
using heat generated within the system to regenerate the molten salts and release carbon dioxide
Data Source
AI summary
The present disclosure provides systems and methods for capturing carbon dioxide using molten salts. Streams comprising carbon dioxide from an industrial may be contacted with a molten borate salt to produce carbon rich streams. The carbon rich streams may be directed to a desorber where the molten salt is regenerated and pure carbon dioxide is released and used elsewhere.