Methane Separation in Direct Iron Reduction Plant
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing direct reduction processes for producing metallic iron face challenges in controlling the methane content in reducing gas, leading to inefficient temperature management in the reaction zone, excessive methane in exhaust gas, and difficulty in controlling carburization, which affects the quality and efficiency of the process.
Innovation Solution
A process that separates methane from synthesis gas entering the plant circuit, allowing precise control of methane levels in the reduction reaction zone and carburization zone, using pure methane as a cooling gas to reduce apparatus size and improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If methane is not separated from synthesis gas, then the reducing gas contains variable methane content, but this leads to inefficient temperature management in the reaction zone and excessive methane in exhaust gas
Solution Approach 1:
The patent applies methane separation by extracting methane from synthesis gas using a processing device (e.g., cryogenic separation, membrane separation, or adsorption). This extraction allows precise control of methane content in the reducing gas fed to the reaction zone, optimizing temperature management while preventing excessive methane from reaching the exhaust gas stream.
2Productivity
If methane content in reducing gas is not controlled, then the process is simpler, but this affects the quality and efficiency of the reduction process
Solution Approach 1:
The patent introduces a methane separation unit that extracts methane from synthesis gas before it enters the reducing gas system. This extraction device, combined with control valves and sensors, enables precise methane content control to optimize reduction efficiency, accepting the necessary increase in system complexity as a trade-off for improved productivity.
Solution Approach 2:
The patent controls the methane content parameter in the reducing gas by adjusting the separation程度 and mixing ratios. By dynamically changing the methane concentration parameter, the system optimizes both temperature management and reduction efficiency, balancing productivity improvement with acceptable device complexity.
3Volume of stationary object
If pure methane is used as cooling gas, then the apparatus size can be reduced, but this requires additional methane processing infrastructure
Solution Approach 1:
The patent applies multi-functionality by using the separated pure methane for multiple purposes: (1) as cooling gas in the cooling zone to reduce apparatus size due to its high calorific value, (2) as a fuel source, and (3) potentially as a raw material for other processes. This multi-use approach justifies the methane processing infrastructure by providing multiple benefits from a single separation unit.
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 enables better control over the reduction process, optimizing reaction kinetics and productivity, reducing re-oxidation of metallic iron, and lowering investment costs by using methane as a high-calorific cooling gas, thus improving the overall efficiency and quality of the direct reduction process.
Implementation Method 1
at stage i) at least a portion of the synthesis gas stream supplied by the external source is made to pass through a processing device to separate the methane from the synthesis gas, forming a fifth stream of pure methane and a sixth stream of reducing gas
Implementation Method 2
heating of the reducing gas mixture in the heating means to a temperature of between 800° C. and 950° C.
Implementation Method 3
a portion into the cooling zone... using methane as a high-calorific cooling gas
Implementation Method 4
direct reduction of iron ore using the appropriately processed synthesis gas obtained from a gasifier as the reducing gas
Implementation Method 5
at least one carbon deposition zone... controlling the carburization process
Data Source
AI summary
Reduction process and relative plant for the production of metallic iron by means of the direct reduction of iron ore, in which a reduction shaft is connected to a source of reducing gas obtained from the gasification of coal. The process advantageously comprises a step in which a portion or all of the synthesis gas entering the plant circuit is processed to separate the methane from the rest of the components of said synthesis gas. The advantageous management of the extracted methane enables the entire reduction process to be optimized, making the efficiency of the process independent of the methane content in the original synthesis gas and making it possible to control the carbon content of the product more accurately and more easily.