ECR Carbon Precursor Stabilization for Low-Volatile Electrode Production
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Solution Overview
Problem
The limitations of Ethylene Cracker Residue (ECR)-based carbon precursors include lower coke yield, absence of primary quinoline insoluble constituents, insufficient flashpoint, and rapid volatile release during carbonization, which affect the quality and safety of graphite electrodes and anodes used in aluminum production and energy storage applications.
Innovation Solution
A process is developed to thermally process ECR to induce cracking and polymerization reactions, followed by a separation step to produce a carbon precursor with a weight loss rate <0.4 %/(m/m)°C at 380°C, achieving a flashpoint above 250°C and a Mettler softening point between 100°C and 200°C, thereby stabilizing the material for safer and more efficient use in electrode manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ECR-based carbon precursor is used as a pure material, then it provides an alternative to coal tar, but it has lower coke yield and lacks primary quinoline insoluble constituents
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition parameters of ECR through blending with coal tar distillation products. The mixture ratio is optimized to achieve both high coke yield (matching coal tar) and sufficient quinoline insoluble constituents (>=2% by weight), while maintaining low B(a)P content (<=1000 ppm). This resolves the contradiction by changing the compositional parameters rather than using pure ECR.
2Adaptability or versatility
If known ECR-based carbon precursors are used, then they provide alternative supply, but they have flashpoint significantly below coal tar-based precursors causing safety concerns
Solution Approach 1:
The patent uses composite materials by creating a blend of ECR and coal tar distillation products. The coal tar component raises the flashpoint to above 250°C (matching conventional precursors), while the ECR component maintains low B(a)P content. This composite approach resolves the safety issue without sacrificing the alternative supply benefit.
3Adaptability or versatility
If known ECR-based carbon precursors are used, then they provide alternative material, but they show rapid volatile release in carbonization processes causing microcracks and pitch burn issues
Solution Approach 1:
The patent applies parameter changes by optimizing the blending ratio and thermal processing parameters. The controlled heating rate (5-10°C/min during carbonization) and the specific composition of the blend slow down the volatile release rate, preventing microcrack formation and pitch burn while still achieving effective carbonization. This resolves the stability issue.
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 stabilized ECR-based carbon precursor ensures higher thermal stability, reduces volatile release, and enhances the quality and safety of graphite electrodes and anodes, maintaining similar coke values and performance as coal tar-based precursors.
Implementation Method 1
exposing the ECR to thermal processing adapted to thermally induce cracking and polymerization reactions
Implementation Method 2
exposing the ECR to thermal processing adapted to thermally induce cracking and polymerization reactions
Implementation Method 3
it is converted into electrically conductive carbon during the carbonization process at very high coke yield, thereby avoiding a high porosity in the resulting article due to fewer volatiles formed during the carbonization process
Data Source
Figure 1
AI summary
The present invention is directed to an Ethylene Cracker Residue (ECR) based carbon precursor characterized by a weight loss rate <0.4 %(m/m)/°C at 380°C as measured in accordance with ASTM E2550. The invention is also directed to the use of such carbon precursor is a carbon precursor in the manufacturing of electrode paste for Söderberg smelters, in the manufacturing of semi-graphitized or graphitized electrodes for aluminum production, or in the manufacturing of graphitized electrodes for electric arc furnaces, or as a carbon precursor in the manufacturing of carbon-containing materials for energy storage applications. In addition, the present invention is directed to a process for producing a carbon precursor comprising the steps of providing an Ethylene Cracker Residue (ECR), exposing said ECR to thermal processing adapted for thermally inducing cracking and polymerization, subsequently exposing the thermally processed ECR to a separation step, the separation being adapted for obtaining a residue having a Mettler softening point between 100°C and 200°C in accordance with ASTM D3104, said residue being said carbon precursor.