ZSM-12 Hydrocracking Catalyst for Distillate Selectivity and Cold Flow
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Solution Overview
Problem
Existing hydrocracking processes struggle to achieve high selectivity and yield of desired middle and heavy distillate products, particularly in the second stage, while maintaining improved cold properties of the products.
Innovation Solution
A hydrocracking catalyst system for the second stage comprising alumina, amorphous silica-alumina (ASA), USY zeolite, and ZSM-12 zeolite, impregnated with metals from Groups 6 and 8-10 of the Periodic Table, is used to enhance the conversion and selectivity of middle and heavy distillates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrocracking catalysts are used in the second stage, then the process is simple and easy to operate, but the selectivity and yield of middle and heavy distillate products are insufficient
Solution Approach 1:
The patent employs a composite catalyst system combining multiple zeolite types (USY and ZSM-12) with metal components (Ni, Mo, W) deposited on a support structure. This composite approach enables simultaneous hydrocracking and hydroisomerization functions, achieving high selectivity for middle and heavy distillates (50-65% selectivity) while maintaining catalyst stability and activity in the second stage hydrocracking process.
2Object-affected harmful factors
If conventional catalysts are used, then the catalyst structure is simple, but the cold flow properties of distillate products are not improved
Solution Approach 1:
The patent introduces ZSM-12 zeolite with specific pore structure (12-membered rings) to selectively promote hydroisomerization of n-paraffins in the distillate range. This local functional enhancement within the catalyst system specifically targets cold flow property improvement through branched isomer formation, while the overall catalyst structure remains integrated with USY and metal components for comprehensive hydrocracking functionality.
3Manufacturing precision
If a single-stage hydrocracking process is used, then the process configuration is simple, but the selectivity for desired distillate products cannot be optimized
Solution Approach 1:
The patent implements a two-stage hydrocracking process where the second stage employs the specialized catalyst system (USY+ZSM-12 with Ni/Mo or Ni/W) to selectively optimize distillate production. This segmentation allows the first stage to handle bulk conversion while the second stage focuses on selective distillate formation and cold flow improvement, achieving high selectivity (50-65%) without requiring complete process redesign.
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 system significantly improves the yield and selectivity of middle and heavy distillate products, achieving at least 50% selectivity for distillates between 380-700°F (193-371°C) and 15-25% for heavy distillates between 530-700°F (277-371°C), while enhancing cold properties compared to traditional catalysts.
Implementation Method 1
A catalyst used in a second stage of a hydrocracking process comprises a base impregnated with metals selected from Group 6 and Groups 8 through 10 of the Periodic Table. The base of the catalyst comprises alumina, an amorphous silica-alumina (ASA) material, a USY zeolite and ZSM-12 zeolite.
Implementation Method 2
The base of the catalyst comprises alumina, an amorphous silica-alumina (ASA) material, a USY zeolite and ZSM-12 zeolite
Data Source
AI summary
The present process comprises hydrocracking a hydrocarbon feed in a first stage. The catalyst in the first stage is a conventional hydrocracking catalyst. The product from the first stage can then be transferred to a second hydrocracking stage. The catalyst used in the second stage of the present hydrocracking process comprises a base impregnated with metals from Group 6 and Groups 8 through 10 of the Periodic Table. The base of the catalyst used in the present second hydrocracking stage comprises alumina, an amorphous silica-alumina (ASA) material, a USY zeolite and zeolite ZSM-12.