Upgraded Coal Graphitization for High-Purity Carbon
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Natural coal, particularly low-rank coal, has undesirable properties such as low carbon concentration, high oxygen content, and high ash content, making it unsuitable for energy generation and production of high-value materials like graphene, and the scarcity of natural graphite limits its availability for applications in lithium-ion batteries and other energy storage solutions.
Innovation Solution
A method involving the carbonization and graphitization of upgraded coal, where coal is cleaned and treated with oxidizable inorganic metallic agents or reducing agents to reduce ash and oxygen content, followed by heating in an inert environment to produce carbonized coal with high fixed carbon content, which is then graphitized to form high-purity graphite.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If natural graphite resources are used, then graphite supply is limited, but demand for graphite in lithium-ion batteries is rapidly growing
Solution Approach 1:
The patent applies preliminary action by upgrading coal before carbonization through chemical treatment with oxidizable inorganic metallic agents or reducing agents. This pre-treatment reduces ash and oxygen content in the coal, preparing it for subsequent carbonization to produce high-purity graphite. By performing these preparatory steps before the main carbonization process, the method ensures that the resulting graphite meets high purity requirements while utilizing abundant coal resources instead of limited natural graphite.
2Quantity of substance
If low-rank coal is used directly, then material cost is low, but the coal has low carbon concentration and high oxygen content making it unsuitable for high-value materials production
Solution Approach 1:
The patent applies parameter changes by systematically modifying the chemical composition of coal through controlled chemical reactions. The coal is treated with oxidizable inorganic metallic agents (such as iron sulfate) or reducing agents to change the oxygen content, ash content, and carbon concentration parameters. These parameter changes transform low-rank coal with poor properties into upgraded coal suitable for high-purity graphite production, directly addressing the contradiction between material availability and quality requirements.
3Manufacturing precision
If coal is carbonized without upgrading, then processing steps are simplified, but the resulting carbonized coal has high ash content and low fixed carbon content
Solution Approach 1:
The patent applies preliminary action by performing chemical upgrading of coal before the carbonization step. The coal undergoes treatment with oxidizable inorganic metallic agents or reducing agents to reduce ash and oxygen content, and increase carbon concentration. This preliminary treatment ensures that when the coal is subsequently carbonized, the resulting carbonized coal achieves high fixed carbon content (80-99 wt%) and low ash content (1-20 wt%), meeting the requirements for high-purity graphite production without requiring additional complex purification steps later.
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 method produces graphite with a fixed carbon content of 99 wt% and low ash content, providing a cost-effective and efficient alternative for lithium-ion batteries and other applications, overcoming the limitations of natural graphite scarcity and coal properties.
Implementation Method 1
heating the upgraded coal in an inert environment, to form a carbonized upgraded coal
Implementation Method 2
graphitizing carbonized upgraded coal, to form the graphite. The graphitizing includes heating the carbonized upgraded coal, the heating including heating to a first graphitization temperature for a first graphitization duration
Data Source
AI summary
A method of forming graphite includes carbonizing an upgraded coal, to form a carbonized upgraded coal. The method also includes graphitizing the carbonized upgraded coal, to form the graphite.