Bimetallic Catalyst for Propane Dehydrogenation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current catalysts for propane dehydrogenation to propylene suffer from rapid deactivation due to high temperatures, leading to low catalyst cycle times and high costs, particularly with noble metals like platinum, and lack efficient, stable, and economical alternatives for continuous production.
Innovation Solution
A bi-metallic catalyst system using a transition metal from group VIB (such as Molybdenum, Chromium, or Tungsten) combined with a metal from group IIIA or IVA (like Tin, Gallium, or Indium) supported on alumina-silicate zeolites, operated at low temperatures and atmospheric pressure, which maintains stability for extended periods without noble metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature is used for propane dehydrogenation to achieve high propylene yield, then conversion rate improves, but catalyst deactivation occurs rapidly due to coke deposition
Solution Approach 1:
The patent employs a bi-metallic catalyst system (Mo-Sn, Mo-Ga, or Mo-In) that enables propane dehydrogenation to proceed at lower temperatures (350-650°C) while maintaining high propylene yield. The synergistic interaction between group VIB and group IIIA/IVA metals modifies the reaction parameters, allowing efficient catalysis without the severe coking problems associated with conventional high-temperature processes.
Solution Approach 2:
The invention uses composite bi-metallic catalysts combining metals from group VIB (Mo, Cr, W) with metals from group IIIA (Ga, In) or IVA (Sn, Pb). This composite structure creates synergistic effects where the combination of two metals provides both high activity for propylene production and enhanced resistance to coke deposition, thereby extending catalyst life while maintaining productivity.
2Reliability
If noble metal catalysts like platinum are used to maintain catalyst stability, then catalyst life improves, but operational costs increase significantly
Solution Approach 1:
The patent replaces expensive noble metal catalysts (platinum, palladium) with economically viable bi-metallic systems composed of base metals from groups VIB, IIIA, and IVA. These non-noble metal combinations provide comparable catalytic performance and stability at a fraction of the cost, making the process economically sustainable for industrial application.
Solution Approach 2:
By changing the metallic composition from noble metals to bi-metallic combinations of base metals, the patent achieves similar catalytic stability and activity. The synergistic interaction between the two base metals compensates for the lower intrinsic activity of individual base metals, maintaining reliable performance without noble metal dependence.
3Productivity
If conventional CrOx-based catalysts are used for propane dehydrogenation, then catalyst activity is maintained, but environmental harm increases due to poisonous nature of chromium
Solution Approach 1:
The patent extracts chromium and other environmentally harmful metals from the catalyst composition. The bi-metallic system exclusively uses metals from groups VIB (Mo, Cr, W), IIIA (B, Al, Ga, In), and IVA (Si, Ge, Sn, Pb), with preferred combinations (Mo-Sn, Mo-Ga, Mo-In) that eliminate toxic CrOx while maintaining catalytic activity. This extraction of harmful substances makes the process environmentally friendly.
Solution Approach 2:
The invention replaces toxic chromium-based catalysts with non-toxic bi-metallic alternatives using abundant base metals. These substitutes provide comparable catalytic performance without the environmental burden of chromium waste, enabling sustainable catalytic propane dehydrogenation.
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 propylene selectivity and conversion rates while extending catalyst life beyond 20 hours, reducing operational costs and eliminating the need for expensive noble metals, with propane conversion ranging from 18-52% and propylene yield of 10-25% at 450°C.
Implementation Method 1
A bi-metallic catalyst system using a transition metal from group VIB (such as Molybdenum, Chromium, or Tungsten) combined with a metal from group IIIA or IVA (like Tin, Gallium, or Indium) supported on alumina-silicate zeolites
Implementation Method 2
Dehydrogenation is an endothermic reaction that requires the high temperature and the mild pressure to obtain the high yield of propylene
Data Source
AI summary
A process and catalyst are provided for the non-oxidative dehydrogenation of propane for the production of propylene as petrochemical building blocks. The process provides a direct single-step gas-phase dehydration of propane mixed with nitrogen in the presence and absence of steam/hydrogen over supported bimetallic alumina-silicates zeolites. The catalyst contains no precious metal entities and may contain one metal from group VIB in combination with another metal from group IIIA or IVA supported on FAU, MFI, KFI, BEA type alumina-silicates zeolites. The process provides a propane conversion of 18% to 52% with a propylene yield of 10% to 25%.