Limestone Calcining Apparatus for High-Purity CO2 Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for firing limestone to produce quicklime result in the release of CO2, which is not efficiently captured, leading to atmospheric emission and contamination, necessitating a solution for purer CO2 separation and utilization.
Innovation Solution
A device with a preheating, firing, and cooling zone configuration that operates in a gas-technically closed system, excluding air to achieve high purity CO2 capture, using techniques such as amine washing, looping, or membrane technology, and employing indirect heating with hot CO2 or electric heating to maintain efficiency and purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional limestone burning methods are used, then the burning process can be carried out continuously, but CO2 emissions are released into the atmosphere without efficient capture
Solution Approach 1:
The burning process is divided into distinct zones: a preheating zone where limestone is heated by hot CO2 gas, and a firing zone where calcination occurs in an oxygen-limited atmosphere. This segmentation allows CO2 to be captured and reused for preheating, preventing atmospheric emission while maintaining continuous operation.
Solution Approach 2:
Hot CO2 gas acts as an intermediary medium, serving dual purposes: it is the product of calcination in the firing zone and simultaneously the heating medium in the preheating zone. This intermediary role enables efficient heat transfer and CO2 capture without requiring external fuel or disrupting continuous operation.
2Quantity of substance
If air is present during limestone burning, then oxygen is available for combustion, but CO2 purity is reduced due to mixing with atmospheric gases
Solution Approach 1:
The firing zone operates in an oxygen-limited atmosphere created by restricting air supply, effectively creating an inert environment where calcination occurs without significant mixing with atmospheric gases. This ensures high CO2 purity in the product gas while maintaining a relatively simple combustion process using the limestone itself as the fuel source.
3Object-generated harmful factors
If CO2 capture and separation systems are implemented, then atmospheric emission is prevented, but system complexity increases
Solution Approach 1:
The CO2 capture, separation, and utilization functions are merged into the existing thermal processing system. The hot CO2 from calcination is directly routed to preheat the limestone feed, combining waste heat recovery with CO2 capture in a single integrated flow path, thereby preventing emission without adding significant system complexity.
Solution Approach 2:
The system uses its own produced CO2 as the heating medium for preheating limestone, making the CO2 capture and utilization self-sufficient. The calcination process itself provides the CO2 needed for heat transfer, eliminating the need for external CO2 sources or complex separation equipment.
4Quantity of substance
If preheating zone is added to recover CO2, then CO2 purity and utilization are improved, but energy requirements for heating increase
Solution Approach 1:
The hot CO2 gas from the firing zone continuously flows through the preheating zone to heat the limestone feed, maintaining a continuous heat transfer process. This eliminates energy losses that would occur with intermittent heating and ensures that the thermal energy in the CO2 is fully utilized before the gas enters the firing zone.
Solution Approach 2:
The system utilizes the thermal energy of hot CO2 gas in the preheating zone, where heat transfer occurs through convection and conduction. The CO2 gas undergoes cooling as it transfers heat to the limestone, and this phase change from hot to cooler gas represents an efficient energy recovery process that reduces overall heating 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 system effectively produces CO2 with a purity of at least 70% and prevents atmospheric emission, enabling efficient separation and utilization of CO2, while maintaining economic viability and adhering to emission standards.
Implementation Method 1
burning the preheated limestone to produce quicklime
Implementation Method 2
indirect heating with hot CO2
Implementation Method 3
electric heating
Implementation Method 4
cooling the quicklime
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a device and a method for burning limestone, as well as the use of a firing zone for burning preheated limestone to produce quicklime. A device (1) for burning limestone (2) comprises a preheating zone (10) for preheating the limestone (2), a firing zone (20) for burning the preheated limestone (2) to produce quicklime (3), and a cooling zone (30) for cooling the quicklime (3). The device (1) has a feed (15) for limestone (2) and a discharge (25) for quicklime (3). The feed (15) and/or the discharge (25) is essentially sealed off from the gas. This allows for the efficient separation of high-purity CO2.