Lime Calcination CO2 Capture via CaO Sorbent Recycling
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Solution Overview
Problem
The calcination process for producing lime or dolime results in significant CO2 emissions and high greenhouse gas contributions, with existing CO2 capture methods either modifying the kiln process or continuously removing unusable waste products, neither of which are suitable for producing marketable lime or dolime.
Innovation Solution
A closed-loop regenerative system that captures CO2 from the gaseous effluent using a CaO sorbent, followed by calcination of the captured CaCO3—CaO charge with low-impurity fuels, recycling the CaO-based sorbent, and introducing fresh limestone to maintain purity and efficiency, thereby reducing CO2 emissions and producing a valuable auxiliary product.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If CO2 capture methods are applied to lime or dolime production, then CO2 emissions are reduced, but the process requires continuous removal of unusable waste products
Solution Approach 1:
The patent implements a closed-loop system where CaO sorbent is continuously regenerated and reused. The CaCO3 captured in the carbonation step is calcined to regenerate CaO, which returns to capture more CO2. This eliminates waste removal while maintaining CO2 capture effectiveness
Solution Approach 2:
The CaO sorbent serves itself by being regenerated through calcination of the captured CaCO3. The system uses its own captured material to regenerate the sorbent, creating a self-sustaining cycle that eliminates external waste disposal requirements
2Object-affected harmful factors
If existing CO2 capture methods are used, then CO2 concentration is reduced in effluent, but the kiln process must be modified
Solution Approach 1:
The patent separates CO2 capture from the main kiln process by adding a distinct carbonation reactor and CaO circulation system. This modular approach allows CO2 capture without fundamentally altering the proven lime/dolime production process
Solution Approach 2:
The CaO/CaCO3 cycle acts as an intermediary system that captures CO2 from the kiln effluent without directly modifying the kiln's core calcination function. The sorbent material mediates between the kiln process and CO2 removal
3Manufacturing precision
If high purity lime or dolime is produced, then product quality is maintained, but CO2 emissions and greenhouse effect increase
Solution Approach 1:
The patent implements continuous CO2 capture through a circulating CaO sorbent system that operates parallel to the continuous lime/dolime production. This allows simultaneous maintenance of high product purity and continuous greenhouse gas reduction
Solution Approach 2:
The patent converts the harmful CO2 emissions into a beneficial resource by capturing it with CaO to form CaCO3, which is then calcined to regenerate CaO. The CO2 that would harm the environment is transformed into part of a regenerative cycle that supports continuous production
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 method effectively reduces CO2 emissions in the atmosphere, maintains high purity of the lime or dolime product, and generates a valuable auxiliary product that can be used in various industries, while minimizing the greenhouse effect and energy costs.
Implementation Method 1
passes through a sorbent material based on CaO which captures CO2 and forms, by carbonation, a CaCO3—CaO based charge
Implementation Method 2
calcination of the separated CaCO3—CaO based charge in contact with second fumes obtained by combustion of a fuel... with, by decarbonation of CaCO3, formation of said CaO-based sorbent material and release of CO2
Implementation Method 3
combustion of a fuel chosen from the group consisting of the gaseous fuels and the solid and liquid fuels having a ash content less than 10 wt % and a sulphur content less than 1.5 wt % in the presence of dioxygen and CO2, as oxidizing gas
Data Source
AI summary
A method for producing lime or dolime, which includes a calcination step for the calcination of calcareous or dolomitic material which is brought into contact with the first fumes which are obtained by combustion of fuel with an oxidizing gas, a cooling of calcined lime or dolime with discharge and collection thereof and a release of a gaseous effluent containing CO2. Subsequent processing steps result in the formation of a CaO-based sorbent material with separation between the CaO-based sorbent material and a CO2-concentrated gas stream which is collected. The recycling of said separated CaO-based sorbent material is recycled into a CO2 depletion step resulting in the extraction of a valorizable fraction of the CaCO3—CaO based charge with a compensatory introduction of fresh CaCO3 in the calcination step.