Hydrocracker Catalyst Beds for Flexible Product Slate Adjustment
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Solution Overview
Problem
Refineries face challenges in adjusting product slates between gasoline and diesel production in response to seasonal market price fluctuations, as existing technologies lack the capability to readily shift production without requiring refinery shutdowns or significant rearrangements during turnarounds, which are costly and time-consuming.
Innovation Solution
A hydrocracking system with a hydrotreater and hydrocracker that includes separate catalyst beds for naphtha and diesel selective hydrocracking, allowing for the recycling of unconverted oil to adjust product proportions by directing it through specific catalyst beds, enabling flexible production shifts between gasoline and diesel without shutdowns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If refineries use conventional hydrocracking technology optimized for maximum product volumes, then productivity is improved, but adaptability to shift between gasoline and diesel production deteriorates
Solution Approach 1:
The hydrocracker is divided into multiple catalyst beds with different selectivities (naphtha-selective catalyst in upper beds, diesel-selective catalyst in lower beds). This segmentation allows independent control of gasoline and diesel production by directing feedstock to specific beds or recycling unconverted oil selectively, enabling the refinery to adapt product slate to market conditions while maintaining high productivity.
2Adaptability or versatility
If refineries conduct turnaround to alter catalysts and plumbing for product adjustment, then adaptability is improved, but loss of time and productivity deteriorates
Solution Approach 1:
The system is pre-configured with multiple catalyst beds containing different selectivity catalysts during the previous turnaround. This preliminary action prepares the system in advance for future product slate adjustments, so that when market conditions change, the refinery can simply adjust operating parameters (feed distribution, recycle ratios) rather than requiring another shutdown for physical reconfiguration.
3Adaptability or versatility
If refineries conduct turnaround to rearrange plumbing for product adjustment, then adaptability is improved, but productivity deteriorates
Solution Approach 1:
The system incorporates dynamic control capabilities through adjustable feed distribution systems and recycle stream control that allow real-time shifting between gasoline and diesel production modes without physical reconfiguration. The multi-bed catalyst system enables dynamic product slate adjustment by varying feedstock distribution and recycle ratios, maintaining continuous operation and high productivity while adapting to market demands.
4Device complexity
If single catalyst bed is used for hydrocracking, then device complexity is reduced, but adaptability to produce different products deteriorates
Solution Approach 1:
The hydrocracker employs multiple catalyst beds with different selectivities (naphtha-selective and diesel-selective catalysts) arranged in sequence. This segmentation provides adaptability to produce different product slates by controlling feed distribution and recycle streams, while the modular bed structure keeps the added complexity manageable and justifiable by the operational flexibility gained.
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 system allows for efficient adjustment of product slates between gasoline and diesel, optimizing profitability by extending run lengths, reducing catalyst deactivation, and improving system utilization, thereby enhancing financial performance and operational efficiency.
Implementation Method 1
a hydrotreater for hydrotreating heavy hydrocarbons to produce hydrotreated heavy hydrocarbons
Implementation Method 2
a hydrocracker for hydrocracking the hydrotreated heavy hydrocarbons
Implementation Method 3
the top fixed bed includes a naphtha selective catalyst and where the hydrocracker further includes a bottom bed below the midpoint inlet and above the outlet and where the bottom bed includes a diesel selective hydrocracking catalyst
Data Source
AI summary
The invention relates to a catalytic hydrocracker with two different catalyst beds within the reactor where each is loaded with a catalyst that has different hydrocracking properties. A first catalyst bed preferably cracks heavy oil more aggressively than the catalyst in the second bed. The catalytic hydrocracker includes further two recycle lines such that one directs unconverted oil through both hydrocracker beds and a bypass inlet is positioned between the first and second catalyst beds to admit unconverted oil to pass only through the second less aggressive hydrocracker catalyst bed. When gasoline prices favor the production of gasoline, less unconverted oil is recycled through the bypass therefore making more gasoline, but when prices favor the production of j et and diesel, more recycle is directed through the bypass recycle thus making less gasoline and more diesel and jet fuel.