Carbon Nanofibers via Binary Nickel Catalyst

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current carbon nanofiber production methods result in lower quality nanofibers due to the deposition of amorphous carbon, which reduces their graphitization degree, specific surface area, and gas adsorption capacity, limiting their industrial applicability and effectiveness in various applications.

Innovation Solution

A method involving a floating catalyst system with nickel and nickel sulfide catalysts, achieving a binary phase condition, allows for faster carbon nanofiber growth and reduced amorphous carbon deposition, enhancing the specific surface area, graphitization degree, and mesopore volume, thereby improving the gas adsorption capacity and overall quality of the nanofibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If standard carbon nanofiber production processes are used, then production capacity is maintained at conventional levels, but the quality of nanofibers deteriorates due to accumulation of amorphous carbon reducing graphitization degree, specific surface area, and gas adsorption capacity

Engineering Contradiction:

Improvequality of carbon nanofibersVSAvoidproduction capacity

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying the catalyst system from conventional single-phase metals to a binary phase catalyst system (nickel-nickel sulfide), and by optimizing reaction parameters including temperature (900-1250°C), gas flow velocity (0.1-12 m/s), and residence time (1-15 s). These parameter changes enable faster nanofiber growth and reduce amorphous carbon deposition, simultaneously improving quality and maintaining production capacity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by using a binary phase catalyst system composed of nickel and nickel sulfide. This composite catalyst structure facilitates faster carbon nanofiber growth and reduces amorphous carbon accumulation compared to conventional single-phase catalysts, thereby improving nanofiber quality while maintaining productivity

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If floating catalyst technique is used, then ease of manufacture is improved by eliminating substrate removal steps, but manufacturing precision deteriorates due to uncontrolled amorphous carbon deposition on nanofiber surfaces

Engineering Contradiction:

Improveprocess simplicityVSAvoidsurface quality of nanofibers

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by changing the catalyst composition parameter from single-phase to binary phase (nickel-nickel sulfide), which fundamentally alters the deposition behavior. This parameter change enables the floating catalyst process to produce high-quality nanofibers with minimal amorphous carbon while maintaining the ease of manufacture advantage of the floating catalyst technique

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The binary phase catalyst system acts as an intermediary that controls the carbon deposition process. The nickel-nickel sulfide catalyst system mediates between the gaseous hydrocarbon feedstock and the nanofiber growth, enabling controlled crystalline carbon deposition while minimizing amorphous carbon formation, thus improving surface quality without sacrificing process simplicity

Inventive Principle:

Principle #24Intermediary (Mediator)

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 significantly increases the production capacity and quality of carbon nanofibers, achieving higher specific surface areas, graphitization degrees, and mesopore volumes, leading to enhanced gas adsorption capabilities and broader industrial applicability.

Implementation Method 1

Carbon nanofibers are graphitic filament structures formed by their growth from the catalytic decomposition of a hydrocarbon in gaseous phase

Methodology Applied

Scientific EffectCatalytic decomposition: Catalysis

Implementation Method 2

The procedure for obtaining the carbon nanofibers is characterized by the use of a specific metallic catalyst and production parameters that allow establishing binary phase conditions in said catalyst which, combined with the chemical composition of the furnace atmosphere and the fluidodynamic conditions verified inside the production furnace, provide a growth of the carbon nanofibers faster than the corresponding to the standard production processes known for carbon nanofibers

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 3

the accumulation of amorphous carbon of pyrolytic origin is negligible, in contrast with other carbon nanofibers of the state of the art

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentUS8124227B2Carbon nanofibers and procedure for obtaining said nanofibers

Publication Date: 2012.02.28 GRP ANTOLIN ING SA

AI summary

The object of the present invention is carbon nanofibers mainly characterized by their high specific volume of mesopores, their high gas adsorption capacity and presenting a graphitic hollow structure. A second object of this invention is a procedure for obtaining such carbon nanofibers, which makes use of a metallic nickel catalyst and specific process furnace parameters that combined with the chemical composition of the furnace atmosphere and the fluidodynamic conditions of the gas stream inside the furnace, result in a faster growth of the carbon nanofibers and also in a higher quality of the carbon nanofibers obtained.