Dual Catalyst System for Ebullated Bed Hydroprocessing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ebullated bed hydroprocessing systems face challenges in efficiently processing heavy oil feedstocks rich in asphaltenes and high boiling fractions due to catalyst fouling, coke precursor formation, and sediment buildup, leading to reduced conversion levels and equipment instability.
Innovation Solution
The implementation of a dual hydroprocessing catalyst system comprising a colloidal or molecular catalyst and a porous supported catalyst, where the colloidal or molecular catalyst is dispersed within the heavy oil feedstock or formed in situ, enhances the processing of asphaltenes, reduces fouling, and increases conversion levels by promoting beneficial upgrading reactions and capping free radicals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a porous supported catalyst is used in ebullated bed hydroprocessing, then the system can process heavy oil feedstocks, but the catalyst becomes fouled by asphaltenes and forms coke precursors, reducing conversion levels
Solution Approach 1:
The patent combines two types of catalysts: a porous supported catalyst for bulk hydrocarbon processing and a colloidal or molecular catalyst for asphaltene-specific reactions. This merging allows the system to simultaneously process both fractions without the asphaltenes fouling the supported catalyst, thereby maintaining high conversion levels while improving catalyst stability.
Solution Approach 2:
The colloidal or molecular catalyst acts as an intermediary that specifically targets asphaltene molecules, preventing them from reaching and fouling the porous supported catalyst. This intermediary catalyst handles the problematic asphaltene fraction, protecting the main catalyst system from fouling and extending its operational life.
2Productivity
If conventional catalysts are used to process asphaltenes, then the system can upgrade feedstocks, but the catalysts deactivate rapidly due to asphaltene deposition
Solution Approach 1:
The patent employs colloidal or molecular catalysts that can be easily separated from the product stream and replaced, rather than relying on expensive porous supported catalysts that require regeneration or replacement due to fouling. These molecular catalysts operate at lower costs and can be quickly replaced if needed, maintaining continuous operation without lengthy maintenance shutdowns.
3Productivity
If high conversion levels are achieved in ebullated bed reactors, then more feedstock is processed, but coke precursors and sediment form, causing equipment fouling
Solution Approach 1:
The patent converts the previously harmful asphaltene molecules into beneficial products by using the colloidal or molecular catalyst to promote their hydroprocessing. Instead of allowing asphaltenes to remain as fouling agents, the system now utilizes them as substrates for catalytic conversion, transforming the harmful factor into a useful process component that increases overall conversion while reducing fouling.
4Adaptability or versatility
If existing ebullated bed systems are upgraded to handle lower quality feedstocks, then more versatile processing is achieved, but the system complexity increases
Solution Approach 1:
The patent creates a universal catalyst system where the porous supported catalyst handles bulk hydrocarbon conversion and the colloidal or molecular catalyst handles asphaltene conversion. This multi-functional approach allows a single integrated system to process a wide range of feedstock qualities, from conventional crude to heavy oil and bitumen, without requiring separate processing lines for different feedstock types.
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 allows for higher conversion levels of heavy oil feedstocks, reduces equipment fouling, and extends the lifespan of catalysts and equipment by effectively processing asphaltenes and other large hydrocarbon molecules, thereby improving the quality of the processed materials and reducing maintenance needs.
Implementation Method 1
employing a colloidal or molecular catalyst and a porous supported catalyst... promotes beneficial upgrading reactions
Implementation Method 2
hydroprocessing heavy oil feedstocks... converting heavy oil into useful end products... reducing the molecular weight of the heavy oil
Data Source
AI summary
An ebullated bed hydroprocessing system, and also a method for upgrading a pre-existing ebullated bed hydroprocessing system, involves introducing a colloidal or molecular catalyst, or a precursor composition capable of forming the colloidal or molecular catalyst, into an ebullated bed reactor. The colloidal or molecular catalyst is formed by intimately mixing a catalyst precursor composition into a heavy oil feedstock and raising the temperature of the feedstock to above the decomposition temperature of the precursor composition to form the colloidal or molecular catalyst in situ. The improved ebullated bed hydroprocessing system includes at least one ebullated bed reactor that employs both a porous supported catalyst and the colloidal or molecular catalyst to catalyze hydroprocessing reactions involving the feedstock and hydrogen. The colloidal or molecular catalyst provides catalyst in what would otherwise constitute catalyst free zones within the ebullated bed hydroprocessing system. Asphaltene or other hydrocarbon molecules too large to diffuse into the pores of the supported catalyst can be upgraded by the colloidal or molecular catalyst. A slurry phase reactor may be positioned upstream from one or more ebullated bed reactors or converted from a pre-existing ebullated bed reactor.