Mo-V-Nb-Sb Catalyst for Stable Oxidation Yield
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Solution Overview
Problem
Current oxide catalysts for vapor-phase catalytic oxidation or ammoxidation of propane or isobutane face challenges in maintaining high yield and long-term stability, with existing catalysts exhibiting low yield and short lifespan due to evaporation of Te and complex operational processes.
Innovation Solution
A catalyst composition of Sb, Mo, V, Nb, and Mn/W with a specific atomic ratio, supported on silica, which allows for high yield and long catalyst lifetime through a simplified production process involving drying and calcination steps without high-temperature hydrothermal treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Te-containing catalysts are used to achieve high initial yield, then the yield is improved, but Te evaporates during reaction causing yield to decrease over time
Solution Approach 1:
The patent removes Te from the catalyst composition entirely, extracting the problematic element that causes evaporation and yield degradation. The catalyst uses Mo-V-Nb-Sb-Mn/W system without Te, eliminating the root cause of yield instability while maintaining high productivity through alternative catalytic active sites.
Solution Approach 2:
The patent changes the chemical composition parameters of the catalyst by replacing Te with Mn and/or W in controlled amounts (0.1-10 wt% Mn and/or 0.1-10 wt% W). This parameter change prevents evaporation while preserving catalytic activity for high-yield production over extended periods.
2Productivity
If hydrothermal treatment at high temperature for prolonged time is used to prepare catalyst, then catalyst performance is improved, but the operational process becomes complex with many steps
Solution Approach 1:
The patent extracts and removes the complex hydrothermal treatment process (including pressurization, filtration, washing, drying steps) from the catalyst preparation methodology. Instead, it employs a simple drying process followed by calcination, eliminating unnecessary operational complexity while achieving superior catalyst performance.
Solution Approach 2:
The patent adopts a simpler, more disposable-friendly preparation approach that doesn't require complex equipment for hydrothermal treatment. The process uses basic drying and calcination steps that are easier to implement and scale industrially, reducing operational complexity.
3Productivity
If Mn or W is added to Mo-V-Nb-Sb system to improve yield, then yield is improved, but the catalyst composition becomes more complex
Solution Approach 1:
The patent applies local quality by adding Mn and/or W in specific, controlled small amounts (0.1-10 wt% each) to the Mo-V-Nb-Sb system. This localized addition of promoter elements improves yield through enhanced catalytic activity at specific sites without significantly complicating the overall catalyst composition or structure.
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 catalyst achieves high yield and stable performance over a prolonged period, simplifying industrial application by reducing the complexity of the production process and preventing Te evaporation, thus maintaining high acrylonitrile or acrylic acid production efficiency.
Implementation Method 1
vapor-phase catalytic oxidation or the vapor-phase catalytic ammoxidation of propane or isobutane
Implementation Method 2
vapor-phase catalytic oxidation or the vapor-phase catalytic ammoxidation
Data Source
AI summary
It is an object to provide a oxide catalyst for producing an unsaturated acid or unsaturated nitrile by which reaction results are good and a high yield can be stably maintained for a prolonged period of time, a process for producing the oxide catalyst, and a process for producing an unsaturated acid or unsaturated nitrile using the oxide catalyst. According to the present invention, there is provided an oxide catalyst represented by following compositional formula (1): Mo1VaSbbNbcMndWeYfOn (1) wherein Y represents at least one element selected from alkaline earth metals and rare earth metals; a, b, c, d, e, f, and n each represents an atomic ratio based on one atom of Mo; 0.1 ≤ a ≤ 1, 0.01 ≤ b ≤ 1, 0.01 ≤ c ≤ 1, 0 < d < 0.08, 0 < e <0.08, 0 < (d+e) ≤ 0.08, 0 ≤ f ≤ 1; and n is a number determined by valencies of the constituent metals.