Electric Calcination Device for Cement Clinker CO2 Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cement industry is a significant emitter of CO2, primarily due to the decarbonation of raw meal during cement clinker production, which poses environmental concerns related to global warming and ocean acidification.
Innovation Solution
A method involving the preheating of cement raw meal, followed by partial decarbonation using electrical energy in a calcination device, where the decarbonated product is reintroduced into the rotary kiln, and the CO2 is drawn off for potential processing or sequestration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fossil fuels or alternative fuels are burned in the rotary kiln for calcination, then the thermal energy requirement is met, but CO2 emissions increase significantly
Solution Approach 1:
The decarbonation process is divided into two separate stages: (1) pre-calcination in a pre-calciner using fossil/alternative fuels to perform partial decarbonation, and (2) final decarbonation in the rotary kiln. This segmentation allows the majority of CO2-emitting decarbonation to occur in the pre-calciner, while the rotary kiln focuses on high-temperature sintering with reduced fuel consumption and lower CO2 emissions.
Solution Approach 2:
The pre-calciner performs preliminary decarbonation of the raw meal before it enters the rotary kiln. By conducting the energy-intensive decarbonation reaction (CaCO3 → CaO + CO2) in advance in the pre-calciner, the amount of CO2 generated during the subsequent rotary kiln operation is significantly reduced, as less limestone needs to be decarbonated at that stage.
2Object-generated harmful factors
If carbon capture and sequestration methods are implemented to separate CO2 from flue gases, then CO2 emissions are reduced, but capital and operating expenditures increase significantly
Solution Approach 1:
The harmful CO2 is extracted and separated from the useful product (calcined clay) in the cyclone separator. The CO2-rich gas phase is drawn off separately through the gas outlet, while the decarbonated solid particles are recovered and returned to the process. This natural separation based on phase and density differences eliminates the need for complex CO2 separation plants.
Solution Approach 2:
The system uses its own operational characteristics to achieve separation: the decarbonation process naturally produces CO2 gas that rises and can be drawn off, while the decarbonated solid particles settle and are returned. The process itself generates the separation opportunity, requiring no external complex separation infrastructure.
3Object-generated harmful factors
If the entire raw meal flow is decarbonated in the pre-calciner, then CO2 emissions from the rotary kiln are reduced, but the pre-calciner becomes overloaded and processing efficiency decreases
Solution Approach 1:
Instead of performing complete decarbonation in the pre-calciner, only partial decarbonation is carried out there (typically 50-70% of total decarbonation). This partial action prevents overloading the pre-calciner while still achieving significant CO2 emission reduction in the rotary kiln, as the majority of decarbonation occurs in the pre-calciner stage.
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 the CO2 footprint of cement production by utilizing electricity for decarbonation, eliminating fossil fuel combustion, and enabling direct CO2 capture for further processing or sequestration, thus minimizing capital and operating expenditures.
Implementation Method 1
the calcination device is heated by electrical energy
Implementation Method 2
at least partially decarbonated in the calcination device in order to obtain an at least partially decarbonated product and CO2
Implementation Method 3
preheating cement raw meal in a preheater string, said preheater string comprising a plurality of preheater stages
Implementation Method 4
introducing the pre-calcined product into a rotary kiln for calcining the pre-calcined product to obtain cement clinker
Data Source
Figure 1
AI summary
Method of producing clinker form cement raw meal A method of producing clinker from cement raw meal, comprising the steps of: - preheating cement raw meal in a preheater string, said preheater string comprising a plurality of preheater stages, - pre-calcining preheated raw meal in a pre-calciner to obtain a pre-calcined product, - introducing the pre-calcined product into a rotary kiln for calcining the pre-calcined product to obtain cement clinker, wherein a partial flow of at least partly preheated raw meal is diverted from the preheater string, introduced into a calcination device and at least partially decarbonated in the calcination device in order to obtain an at least partially decarbonated product and CO2, wherein the calcination device is heated by electrical energy, and wherein the at least partially decarbonated product is fed into the rotary kiln and the CO2 is drawn off from the calcination device.