Clinker Manufacturing CO2 Separation via Precalcination Stream Segmentation

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Solution Overview

Problem

Clinker manufacturing processes emit significant CO2 emissions, and existing reduction methods, whether primary or secondary, face limitations in achieving substantial reductions beyond 20% due to logistical issues and high costs.

Innovation Solution

A process involving preheating, precalcination, and calcination in a rotary kiln where CO2-rich combustion fumes from precalcination are subjected to separate CO2 elimination treatment without mixing with calcination fumes, and oxycombustion is used to enrich CO2 concentrations, allowing for indirect heat recovery and reduced flow rates for more efficient CO2 removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If CO2 elimination treatment is applied to mixed combustion fumes from precalcination and calcination, then the CO2 removal process is simpler, but the CO2 concentration is lower and the flow rate is higher making removal less efficient

Engineering Contradiction:
ImproveCO2 removal process complexityVSAvoidCO2 removal efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the combustion fumes into two separate streams: precalcination fumes and calcination fumes. Each stream is treated separately, with precalcination fumes being directed to a CO2 elimination unit while calcination fumes are recycled to the kiln. This segmentation allows the CO2 removal process to target a specific stream with higher CO2 concentration and lower flow rate, improving removal efficiency despite adding process complexity.

Inventive Principle:
Principle #1Segmentation

2Productivity

If oxycombustion is used to enrich CO2 concentration, then CO2 removal becomes more efficient, but the process cost increases

Engineering Contradiction:
ImproveCO2 removal efficiencyVSAvoidprocess cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies oxycombustion locally to the precalcination process rather than the entire clinker manufacturing process. By enriching only the precalcination zone with oxygen to achieve higher CO2 concentration in its fumes, the system achieves efficient CO2 removal while limiting the cost increase to a specific process stage rather than the entire operation.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If precalcination fumes are mixed with calcination fumes, then the overall fume flow is more uniform, but the CO2 concentration is diluted reducing removal efficiency

Engineering Contradiction:
Improvefume flow uniformityVSAvoidCO2 concentration
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent extracts the precalcination fumes stream from the mixed fume system and directs it separately to a CO2 elimination unit. This extraction prevents the dilution of CO2 concentration that would occur if the fumes were mixed with calcination fumes, while still maintaining overall process stability through separate but coordinated control of each fume stream.

Inventive Principle:
Principle #2Taking out (Extraction)

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 process concentrates CO2 emissions at higher concentrations, reducing the flow rate and making CO2 removal more profitable, potentially achieving CO2 reductions beyond 50% while maintaining process viability and controlling costs.

Implementation Method 1

preheating the raw material using combustion fumes

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

the precalcination of the preheated raw material using combustion

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

calcining the precalcined raw material in a rotary kiln

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

the calcining reaction of the limestone, which releases a very large quantity of CO2

Methodology Applied
Scientific EffectCalcination reaction: Decomposition (biological)

Data Source

PatentEP2091886B1Process for manufacturing clinker with controlled co2 emission
Publication Date: 2017.05.10 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE

AI summary

The invention relates to a process for manufacturing clinker from a raw mix, implementing the following: preheating of the raw mix by combustion flue gases; precalcination of the raw mix; and calcination of the precalcined raw mix in a rotary kiln, in which process the precalcination and the calcination in the rotary kiln produce combustion flue gases that contain CO2, in which the combustion flue gases created by the precalcination undergo a CO2-removal treatment without said flue gases mixing with the combustion flue gases created by the calcination in the rotary kiln.