Lignin Coke Graphite Property Control
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Solution Overview
Problem
The use of lignin as a precursor for carbon products has been hindered by its amorphous and highly functionalized nature, leading to limited success in producing high-quality carbon-based materials, despite its potential due to its high aromatic content and coking value.
Innovation Solution
A method involving mixing coke derived from a petroleum product with a sufficient quantity of coke derived from lignin to form a green mixture, which is then carbonized and graphitized, allowing for the adjustment of selected properties of the graphite article, such as CTE and d 002 spacing, to achieve desired properties not attainable with coke from the petroleum product alone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If lignin is used as a precursor for carbon products, then the aromatic content and coking value are improved, but the amorphous and highly functionalized nature leads to poor manufacturing success
Solution Approach 1:
The patent combines lignin-based coke with petroleum-based coke to create a composite material. The petroleum-based coke serves as a matrix that provides structural integrity and graphitizability, while the lignin-based coke contributes aromatic content and modifies specific properties like CTE and electrical resistance. This composite approach allows the benefits of lignin's high aromatic content to be realized while overcoming its amorphous nature through the petroleum coke framework.
Solution Approach 2:
The patent modifies the chemical composition parameters of the coke precursor by controlling the ratio of lignin-based coke to petroleum-based coke. By adjusting this composition parameter and controlling the coking and graphitization process parameters (temperature, atmosphere, duration), the patent transforms the amorphous lignin structure into a graphitic structure with desired properties, thereby improving manufacturing success.
2Stability of the object's composition
If only petroleum product coke is used, then manufacturing consistency is maintained, but property adjustment flexibility is limited
Solution Approach 1:
The patent uses parameter changes by adjusting the composition ratio of lignin-based coke to petroleum-based coke to achieve different property profiles. By varying this key parameter, the patent can tune properties such as CTE, electrical resistance, and density while maintaining manufacturing consistency through controlled processing conditions. This provides flexibility in designing graphite articles with specific properties.
Solution Approach 2:
The composite material system allows for property adjustment flexibility by varying the proportion of lignin-based coke in the mixture. The petroleum-based coke provides a consistent baseline, while the lignin-based coke acts as a modifier that can be adjusted to achieve desired property ranges, thereby combining manufacturing consistency with adaptability.
3Adaptability or versatility
If lignin content in the mixture is increased, then property customization is improved, but structural integrity may deteriorate
Solution Approach 1:
The patent employs composite materials where the petroleum-based coke forms a structural matrix that maintains structural integrity, while the lignin-based coke is incorporated in controlled amounts to customize properties. The interaction between the two coke types creates a composite structure that leverages the strength of petroleum coke while incorporating the property-modifying benefits of lignin coke.
Solution Approach 2:
The patent controls the lignin content parameter within specific ranges to balance property customization with structural integrity. By optimizing this composition parameter and adjusting processing parameters (coking temperature, graphitization conditions), the patent achieves desired property customization while maintaining adequate structural strength for practical applications.
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 the production of graphite articles with improved properties, such as increased CTE and specific resistance, while maintaining or enhancing bulk density, by effectively utilizing lignin as a precursor, thereby overcoming the limitations of using lignin in carbon product manufacturing.
Implementation Method 1
The green mixture is carbonized and graphitized
Implementation Method 2
The green mixture is carbonized and graphitized
Implementation Method 3
The precursor mixture is coked to thereby forming a coke
Data Source
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AI summary
A precursor having at least five percent of lignin based coke and d002 spacing of more than 3.36 angstroms and less 3.44 for making graphite. Methods for making a green/ graphite article include mixing coke derived from a petroleum product, a coal product or a bitumen product with coke derived from lignin. Alternatively, the precursor material for the various types of coke may be mixed and coked together. The mixture may be formed into a desired shape. The article may be subsequently carbonized and graphitized. The amount of lignin derived coke comprises a sufficient quantity to change at least a selected property of the graphite article.