Synthetic Pitch Production via Thermal Oxidative Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for producing synthetic pitches face challenges in achieving high softening points, maximizing carbon yield, and minimizing primary Quinoline Insoluble (QI) content, while dealing with equipment maintenance issues due to high distillation temperatures and impurities.
Innovation Solution
A process involving thermal oxidative polymerization of medium and heavy aromatic oils at controlled temperatures and oxygen levels, followed by a subsequent thermal treatment, to produce synthetic pitches with enhanced carbon yield and controlled microstructure, minimizing secondary QI content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high distillation temperatures are used to obtain high softening point pitches, then softening point is improved, but equipment maintenance difficulty increases and energy consumption increases
Solution Approach 1:
The invention changes the chemical composition parameters of the feedstock by selecting specific aromatic oil ranges (anthracene oil at 80-100°C, decant oil at 150-200°C, or their mixtures) and controlling the oxidative polymerization conditions (oxygen content 1-11%, temperature 20-100°C, duration 1-48 hours). This transforms the process from thermal distillation to chemical polymerization, achieving high softening points (100-300°C) without high temperature processing that would damage equipment
Solution Approach 2:
The invention replaces the mechanical/thermal separation process (distillation) with a chemical reaction process (oxidative polymerization). Instead of using high temperature to separate and concentrate pitch components through phase change, the process uses controlled oxidation to polymerize aromatic compounds into high molecular weight pitch structures, achieving the same softening point improvement through chemical transformation rather than thermal processing
2Productivity
If conventional oxidative treatment is used to polymerize aromatic oils, then pitch production is achieved, but carbon yield is limited and softening point is insufficient
Solution Approach 1:
The invention optimizes multiple parameters simultaneously: oxygen content (1-11% range), temperature (20-100°C range), treatment duration (1-48 hours), and feedstock composition (different aromatic oil ratios). This multi-parameter optimization enables control over the degree of polymerization, achieving both high carbon yield (60-80%) and high softening point (100-300°C) that cannot be achieved with conventional single-parameter treatment
Solution Approach 2:
The invention uses composite feedstock systems combining different aromatic oils (anthracene oil, decant oil, and/or vacuum residue) in specific ratios. This composite approach allows the reaction mixture to contain a range of aromatic compounds with different reactivities and molecular structures, promoting more complete polymerization and cross-linking that increases both carbon yield and softening point of the final pitch product
3Manufacturing precision
If primary QI removal is performed through high temperature distillation, then pitch quality for graphite electrodes is improved, but energy consumption increases and equipment complexity increases
Solution Approach 1:
The invention performs preliminary oxidative polymerization treatment on the aromatic oils before distillation. This pre-treatment converts lighter, more volatile aromatic compounds into higher molecular weight pitch structures with higher softening points. As a result, the subsequent distillation requires lower temperatures and shorter times to achieve the same pitch quality, reducing energy consumption and equipment complexity while still effectively removing primary QI
Solution Approach 2:
The invention skips the conventional high-temperature, long-duration distillation process by using oxidative polymerization to pre-concentrate and pre-condense the pitch-forming components. This allows the process to rush through the quality improvement stage more efficiently, achieving the necessary pitch specifications with lower energy input and simpler equipment requirements
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 process achieves higher carbon yield and softening points without the need for high distillation temperatures, reducing equipment maintenance and improving the quality of synthetic pitches for advanced carbon materials.
Implementation Method 1
reacting the cited at least one oil with an O2 stream or an O2-enriched air stream containing at least 21% O2 v/v in the reactor at a temperature of between 350 and 400°C and a pressure of at least 11 bar during a residence time of between 5 min and 5h
Implementation Method 2
setting an initial reactor temperature below the starting boiling point of the at least one oil, and reacting the cited at least one oil with an O2 stream... at a temperature of between 350 and 400°C
Implementation Method 3
reacting the cited at least one oil with an O2 stream or an O2-enriched air stream containing at least 21% O2 v/v in the reactor at a temperature of between 350 and 400°C and a pressure of at least 11 bar
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The present invention relates to a process for producing precursors of carbon materials particularly from medium and heavy aromatic oils by thermal oxidative polymerization reactions, so the invention belongs to the field of obtaining carbon precursors from different sources improving total carbon yield.