Pyrocarbon Densification with Recycled Polyaromatic Effluent
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for densifying porous structures by chemical vapor infiltration are costly due to the high carbon content required in the reactive gaseous phase, and they do not effectively recycle polyaromatic hydrocarbons, leading to waste and increased costs.
Innovation Solution
Introducing a fraction of polyaromatic hydrocarbon compounds into the reactive gaseous phase at the inlet of the densification furnace, which are extracted and reintroduced, allowing for a reduction in the overall quantity of reactive gaseous phase needed, thereby reducing costs and waste by utilizing the high carbon content of these compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carbon-rich reactive gaseous phase is used to ensure effective densification, then the densification quality is improved, but the cost increases
Solution Approach 1:
The patent recovers polyaromatic hydrocarbons from the effluent gas after densification and reintroduces them into the reactive gaseous phase. This recycling process reduces the need for continuously introducing expensive carbon-rich gases while maintaining effective carbon deposition for densification, thereby reducing costs without compromising densification quality
Solution Approach 2:
The system implements a feedback loop where effluent gas is analyzed and polyaromatic hydrocarbons are selectively recovered and fed back into the reactive gaseous phase. This closed-loop approach optimizes carbon utilization by continuously adjusting the composition of the reactive gas based on the actual densification needs and effluent composition
2Quantity of substance
If polyaromatic hydrocarbons are recovered and reintroduced to reduce reactive gaseous phase consumption, then cost is reduced, but the polyaromatic hydrocarbons are not upgraded and may cause accumulation
Solution Approach 1:
The patent introduces polyaromatic hydrocarbons with specific molecular weight parameters into the reactive gaseous phase. By controlling the molecular weight distribution and composition of the polyaromatic hydrocarbons, the system optimizes carbon deposition efficiency while preventing accumulation of unwanted byproducts, thus reducing both cost and waste
3Quantity of substance
If the quantity of reactive gaseous phase is reduced by introducing polyaromatic hydrocarbons, then cost is reduced, but the densification effectiveness may be compromised
Solution Approach 1:
The reactive gaseous phase is formulated as a composite mixture containing both traditional carbon precursors and polyaromatic hydrocarbons. This composite composition leverages the complementary properties of different carbon sources: the traditional precursors provide reliable carbon deposition while the polyaromatic hydrocarbons contribute high carbon content and promote graphitization, achieving effective densification with reduced overall gas consumption
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 reduces the amount of reactive gaseous phase necessary for densification, lowering costs and minimizing waste by reusing polyaromatic hydrocarbons without the need for transformation, while maintaining effective densification of porous substrates with pyrolytic carbon.
Implementation Method 1
densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration
Implementation Method 2
reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates to deposit pyrocarbon
Implementation Method 3
admitting, at the inlet of the densification furnace, a reactive gaseous phase comprising at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates
Implementation Method 4
extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace
Data Source
AI summary
A method for densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration, includes admitting, at the inlet of the densification furnace, a reactive gaseous phase including at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates; extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace, wherein the fraction of the gaseous effluents introduced with the reactive gaseous phase includes at least one polyaromatic hydrocarbon compound.