Blast Furnace Methane Reducing Agent Temperature Control
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Solution Overview
Problem
Existing methods for operating blast furnaces that reform carbon monoxide and carbon dioxide into hydrocarbons to reduce carbon dioxide emissions can cause operational problems such as insufficient heating and pressure drops when the amount of methane used as a reducing agent exceeds a certain level.
Innovation Solution
Using oxygen gas instead of hot blast air as the blast gas and regenerating methane from blast furnace by-product gas to maintain stable tuyere-outlet temperatures between 2000 °C to 2400 °C, even with high methane usage, by suppressing nitrogen's non-reactive contribution and ensuring sufficient flame temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the amount of methane blown into the blast furnace as reducing agent is increased to further reduce carbon dioxide emissions, then carbon dioxide emissions are reduced, but the tuyere-outlet temperature decreases significantly causing operational problems
Solution Approach 1:
The patent changes the chemical composition parameter of the reducing agent from traditional carbon-based materials to methane, and controls the amount of methane blown to 30-70 kg/t of hot metal to maintain tuyere-outlet temperature above 1900°C while reducing CO2 emissions
Solution Approach 2:
The patent implements feedback control by monitoring tuyere-outlet temperature and adjusting the methane blowing amount accordingly, ensuring the temperature remains within the optimal range of 1900-2400°C to prevent operational problems while maximizing CO2 reduction
2Object-generated harmful factors
If the amount of methane blown into the blast furnace as reducing agent is increased, then carbon dioxide emissions are reduced, but pressure drop increases and tapping failure occurs
Solution Approach 1:
The patent optimizes the methane blowing amount parameter to 30-70 kg/t of hot metal, which is sufficient to reduce CO2 emissions while maintaining stable operation and avoiding pressure drop increase and tapping failure
Solution Approach 2:
The patent uses feedback control to monitor operational parameters such as pressure drop and tapping conditions, and adjusts the methane blowing amount to maintain reliable operation while achieving CO2 reduction goals
3Object-generated harmful factors
If the amount of methane blown into the blast furnace as reducing agent is increased, then carbon dioxide emissions are reduced, but insufficient heating of the bottom of the blast furnace occurs
Solution Approach 1:
The patent controls the methane blowing amount within 30-70 kg/t of hot metal and maintains tuyere-outlet temperature above 1900°C to ensure sufficient heat generation at the bottom of the blast furnace while reducing CO2 emissions
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 allows for further reduction of carbon dioxide emissions while maintaining stable blast furnace operation and reducing the need for coke and pulverized coal, ensuring efficient energy use and operational stability.
Implementation Method 1
the combustion of the blown reducing agent and coke in the combustion area (raceway) near the outlet of the tuyere
Implementation Method 2
when methane is blown as a reducing agent into the blast furnace from the tuyere, the following reaction occurs in the raceway
Implementation Method 3
These carbon monoxide and hydrogen gases reduce iron ore charged into the blast furnace
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
Provided is a method of operating a blast furnace, including separating carbon dioxide gas from a by-product gas discharged from the blast furnace, generating a regenerative methane gas from the carbon dioxide gas, and blowing a blast gas and a reducing agent into the blast furnace from a tuyere, in which the blast gas is oxygen gas and the regenerative methane gas is used as at least part of the reducing agent.