Ebullated Bed Catalyst Segmentation for Sediment Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ebullated bed processes for hydroconversion of heavy hydrocarbon feedstocks result in high sediment yields, which is undesirable, and existing solutions either do not effectively reduce sediment or compromise hydrodesulfurization performance.
Innovation Solution
The method involves operating an ebullated bed process with a catalyst bed comprising first and second shaped hydroprocessing catalyst particles having specific geometric ratios, where the second catalyst particles have a larger cross section perimeter-to-cross sectional area ratio, allowing for incremental replacement of the first particles to reduce sediment content without sacrificing hydrodesulfurization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If conventional ebullated bed processes use larger particle size catalysts for hydroconversion of heavy hydrocarbon feedstocks, then the process operates with conventional catalyst design, but the sediment yield is high which is undesirable
Solution Approach 1:
The catalyst bed is segmented into two distinct zones: an upper ebullated bed zone containing larger particles (0.5-2.0 mm) for hydrodesulfurization, and a lower fluidized bed zone containing smaller particles (1-50 μm) for hydroconversion. This spatial segmentation allows each zone to perform its specific function optimally, reducing overall sediment yield while maintaining hydrodesulfurization performance.
Solution Approach 2:
Different catalyst particle sizes and properties are assigned to different locations within the reactor. The upper zone uses larger particles optimized for desulfurization, while the lower zone uses smaller particles optimized for conversion. This local optimization of catalyst properties resolves the contradiction between reducing sediment and maintaining desulfurization efficiency.
2Object-generated harmful factors
If a two-step process with different catalysts is used to inhibit sediment formation, then sediment formation is reduced, but the process complexity increases
Solution Approach 1:
The patent merges the functions of two separate catalyst beds into a single integrated ebullated bed reactor. The larger particles serve as both the structural bed material and the active catalyst for hydrodesulfurization, while smaller catalyst particles are suspended in the lower zone for hydroconversion. This consolidation reduces equipment complexity compared to truly separate two-step processes while still achieving low sediment yield through the dual-zone approach.
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 significantly reduces sediment yield in the heavy hydrocarbon conversion product while maintaining or slightly improving hydrodesulfurization performance, achieving lower sediment content than conventional processes with minimal impact on desulfurization functions.
Implementation Method 1
an ebullated bed reactor system, comprising an ebullated bed reactor vessel that defines a reactor volume within which is an ebullated bed reaction zone defined by a catalyst bed comprising first shaped hydroprocessing catalyst particles
Implementation Method 2
operating an ebullated bed process for the hydroconversion of a heavy hydrocarbon feedstock
Data Source
Figure 1
AI summary
An improved method of operating a conventional ebullated bed process for the hydroconversion of heavy hydrocarbon feedstocks so as to provide for low or reduced sediment content in the conversion product without the loss of hydrodesulfurization function.