Bifunctional Pd-Pt/Sulfated Zirconia Catalyst for Simultaneous Desulfurization and Isomerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional isomerization processes for light hydrocarbon oils require a separate hydrodesulfurization step due to sulfur compound poisoning, making them economically and facility-wise inefficient, and existing catalysts lack sufficient sulfur tolerance and activity for simultaneous hydrodesulfurization and isomerization.
Innovation Solution
A catalyst is developed by supporting palladium on a mixture of platinum-supported sulfated zirconia and alumina, with specific surface area and metal content ranges, allowing for simultaneous hydrodesulfurization and isomerization of sulfur-containing hydrocarbon oils without the need for a prior desulfurization step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional solid acid catalyst is used for isomerization, then isomerization activity is achieved, but the catalyst is rapidly poisoned by sulfur compounds in the feedstock
Solution Approach 1:
The patent combines hydrodesulfurization function and isomerization function into a single bifunctional catalyst by supporting platinum and palladium on sulfated zirconia. This merging eliminates the need for separate pretreatment and reaction steps, allowing the catalyst to simultaneously remove sulfur compounds and perform isomerization, thereby resolving the catalyst poisoning problem while maintaining isomerization activity.
Solution Approach 2:
The patent creates a composite catalyst material consisting of sulfated zirconia support with supported platinum and palladium metals. This composite structure provides both the acid sites necessary for isomerization and the metal sites for hydrodesulfurization, enabling the catalyst to resist sulfur poisoning while maintaining high isomerization activity.
2Reliability
If a two-stage treatment process is used for desulfurization followed by isomerization, then sulfur content is reduced to several ppm, but the process requires complex facilities and higher costs
Solution Approach 1:
The patent merges the desulfurization step and isomerization step into a single reaction step using a bifunctional catalyst. This combination allows both functions to occur simultaneously in one reactor, eliminating the need for separate desulfurization facilities and reducing overall process complexity while maintaining high desulfurization efficiency.
Solution Approach 2:
The bifunctional catalyst performs multiple functions simultaneously: it acts as both a hydrodesulfurization catalyst (removing sulfur compounds) and an isomerization catalyst (isomerizing light naphtha). This multi-functionality allows a single catalyst system to replace what previously required two separate process units, thereby simplifying the overall process facilities.
3Productivity
If existing sulfated zirconia catalysts with platinum are used, then simultaneous desulfurization and isomerization is achieved, but sulfur tolerance and activity are insufficient
Solution Approach 1:
The patent develops a composite catalyst system where both platinum and palladium are supported on sulfated zirconia. This composite material combines the advantages of both metals: platinum provides high activity for hydrodesulfurization while palladium enhances sulfur tolerance and isomerization activity. The synergistic interaction between the two metals and the sulfated zirconia support achieves both high productivity and high sulfur tolerance.
Solution Approach 2:
The patent optimizes the composition parameters of the catalyst, specifically the ratios of platinum to palladium and the sulfur content on the zirconia support. By adjusting these parameters, the catalyst achieves optimal balance between reaction activity and sulfur tolerance, overcoming the limitations of existing single-metal catalysts.
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 stable, long-term treatment of hydrocarbon oils with high sulfur concentrations, maintaining isomerization activity and reducing sulfur content to several ppm, thus enabling more economical and facility-simplified isomerization processes.
Implementation Method 1
a light naphtha containing sulfur compounds is treated with a Co—Mo based or Ni—Mo based hydrodesulfurization catalyst to convert organosulfur compounds into hydrogen sulfide
Implementation Method 2
A catalyst is developed by supporting palladium on a mixture of platinum-supported sulfated zirconia and alumina
Data Source
AI summary
A process for producing a catalyst for hydrodesulfurization and isomerization of a sulfur-containing hydrocarbon oil, which comprises supporting palladium on a composition comprising a platinum-supported sulfated zirconia and alumina.