Unsupported Nickel Oxide Nanoparticles for Methane Decomposition

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Solution Overview

Problem

Existing methods for decomposing methane to produce hydrogen often result in carbon monoxide contamination and require high temperatures, with catalyst degradation due to carbon deposition, necessitating frequent regeneration steps.

Innovation Solution

The use of unsupported, nanometer-sized nickel oxide particles as catalyst precursors, produced through a precipitation process, which are reduced with hydrogen before methane decomposition, allowing for carbon monoxide-free hydrogen production at lower temperatures and extended catalyst stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If supported metal catalyst particles are used for methane decomposition, then hydrogen production is achieved, but carbon monoxide contamination occurs and catalyst degradation happens due to carbon deposition

Engineering Contradiction:

Improvehydrogen production rateVSAvoidcarbon monoxide contamination

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates the oxygen-containing catalyst support component that causes carbon monoxide formation. By using unsupported nickel oxide nanoparticles instead of supported catalysts (such as nickel on alumina or ceria), the source of CO contamination is removed while retaining the hydrogen production function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention employs a regenerable catalyst system where the nickel oxide nanoparticles can be periodically regenerated by steam treatment to remove carbon deposits. This allows the catalyst to be reused multiple times after regeneration, balancing the short operational life between regeneration cycles with overall process sustainability.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If conventional catalysts are used for methane decomposition, then hydrogen is produced, but high temperatures are required and catalyst activity decreases over time

Engineering Contradiction:

Improvehydrogen productionVSAvoidoperating temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The invention changes the physical parameters of the catalyst by reducing nickel oxide to metallic nickel through hydrogen reduction at 450°C before methane decomposition. This pre-reduction step creates highly active nickel metal particles that enable methane decomposition at lower temperatures (300-500°C) compared to conventional unsupported or supported catalysts.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If methane decomposition is conducted continuously, then hydrogen production is maintained, but carbon deposits accumulate on the catalyst requiring frequent regeneration

Engineering Contradiction:

Improvecontinuous hydrogen productionVSAvoidcatalyst stability

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The invention implements a periodic operation mode where methane decomposition is alternated with steam treatment cycles. During the decomposition phase, hydrogen is produced while carbon deposits gradually form. When carbon accumulation reaches a certain level, steam is introduced to gasify the carbon deposits, regenerating the catalyst for the next decomposition cycle. This periodic alternation maintains continuous hydrogen production while managing catalyst deactivation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The invention recovers catalyst activity by removing carbon deposits through steam gasification. The steam treatment converts deposited carbon into carbon monoxide and hydrogen, thereby regenerating the catalyst surface for continued methane decomposition. This recovery process extends the operational life of the catalyst between regeneration events.

Inventive Principle:

Principle #34Discarding and recovering

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 achieves high and sustained methane conversion rates with minimal carbon monoxide production, maintaining catalytic activity for several hours before carbon removal is necessary, and allows for repeated methane decomposition and carbon regeneration cycles.

Implementation Method 1

The nickel oxide particles are reduced with hydrogen before hydrocarbon decomposition begins

Methodology Applied

Scientific EffectReduction: Reduction

Implementation Method 2

Methane has been decomposed over supported metal catalyst particles at temperatures of about 300° C. to 500° C. to produce hydrogen and carbon

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 3

it can be re-generated by passing hot steam over the catalyst bed to oxidize the carbon to carbon dioxide and form more hydrogen

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS7470647B2Nickel oxide nanoparticles as catalyst precursor for hydrogen production

Publication Date: 2008.12.30 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

Decomposition of methane to produce carbon monoxide-free hydrogen is accomplished using un-supported, nanometer sized, hydrogen reduced, nickel oxide particles made by a precipitation process. A nickel compound, such as NiCl2 or Ni(NO3) is dissolved in water and suitably precipitated as nickel hydroxide. The precipitate is separated, dried and calcined to form the NiO catalyst precursor particles.