Multimetallic Catalyst Preparation for C5+ Selectivity and Coke Reduction
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Solution Overview
Problem
Current catalytic reforming technologies face challenges in achieving high selectivity for C5+ compounds while minimizing coke formation and improving catalyst stability, particularly with the use of platinum group metals and promoters like bismuth and phosphorus.
Innovation Solution
A catalyst comprising a platinum group metal, tin, a phosphorus promoter, a halogenated compound, and a porous alumina support, with specific promoter ratios and preparation methods that include introducing phosphorus and promoters during support synthesis, resulting in improved catalytic performance and reduced coke formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If bismuth is added to the support, then coke formation is slowed down, but C5+ yield is reduced
Solution Approach 1:
The patent changes the chemical composition parameters by introducing phosphorus as an additional promoter element alongside bismuth. This parameter modification allows the system to achieve both reduced coke formation (through Bi) and maintained C5+ yield (through P promotion), resolving the trade-off between these two opposing effects.
Solution Approach 2:
The patent creates a composite promoter system combining bismuth and phosphorus on the alumina support. This composite approach allows the synergistic interaction between Bi (which reduces coke) and P (which promotes C5+ formation), enabling simultaneous achievement of both benefits rather than having to choose one promoter over the other.
2Productivity
If phosphorus is added to increase C5+ yield, then aromatic production is improved, but catalyst stability is reduced
Solution Approach 1:
The patent combines phosphorus with bismuth to create a stable composite promoter system. The bismuth component provides structural stability and coke reduction, while phosphorus maintains its aromatic promotion function. This composite structure allows phosphorus to be present at effective levels without compromising overall catalyst stability.
Solution Approach 2:
The patent creates different local chemical environments on the catalyst surface by distributing Bi and P promoters across the alumina support. Phosphorus provides local aromatic promotion activity while bismuth provides local stability and coke resistance, allowing both functions to coexist in different regions of the catalyst.
3Productivity
If multiple promoters are added to improve performance, then catalytic activity is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates both bismuth and phosphorus promoters during the support synthesis stage rather than adding them separately later. This preliminary incorporation simplifies the manufacturing process by combining multiple promoter addition steps into a single integrated procedure, reducing operational complexity while maintaining the benefits of multiple promoters.
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 exhibits enhanced selectivity for C5+ compounds and reduced coke formation, with optimized aromatic yields and stability, as demonstrated by NMR and infrared spectroscopy analysis.
Implementation Method 1
phosphorus, less than 1% by weight, stabilizes the support by allowing better retention of specific surface area and chlorine during its use in production processes
Implementation Method 2
carbon monoxide preferentially adsorbs on platinum. This adsorption takes place via two bonds: a σ bond from a p orbital of CO to a vacant d orbital of the metal
Implementation Method 3
a π back bond from a full d orbital to the empty antibonding orbital of CO
Implementation Method 4
The present invention relates to the field of hydrocarbon conversion and more specifically to the reforming of hydrocarbon feedstocks in the presence of a catalyst to produce gasoline cuts
Data Source
Figure 1
AI summary
The invention relates to a method for preparing a catalyst including at least one metal M of the platinum group, tin, a phosphorus promoter, a halide compound, a porous substrate, and at least one promoter X1 selected from the group comprising gallium, indium, thallium, arsenic, antimony and bismuth. The X1 promoter(s) and the phosphorus are added during one or more sub-steps a1) or a2), the sub-step a1) corresponding to the synthesis of the precursor of the dominant oxide and the sub-step a2) corresponding to the shaping of the substrate. The tin is added during one at least of the sub-steps a1) and a2). The product is dried and calcinated before depositing at least one metal M of the platinum group. The assembly is then dried under a neutral gas flow or an oxygen-containing gas flow and further calcinated. The invention also relates to the use of the catalyst obtained by said method in catalytic-reforming or aromatic production reactions.