Hydroprocessing Apparatus with Split Hydrogen Compression
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Solution Overview
Problem
Current hydroprocessing methods face challenges in producing sufficient diesel fuel that meets stringent sulfur and nitrogen contaminant limits, particularly when integrating hydrocracking and hydrotreating units operating at different pressures, and require efficient hydrogen supply systems to optimize diesel production.
Innovation Solution
The proposed solution involves a system with a make-up hydrogen line, compressors, and split lines to compress and distribute hydrogen streams effectively between hydrocracking and hydrotreating units, allowing for efficient hydroprocessing of two hydrocarbon streams at different pressures, enabling the production of high-quality diesel by optimizing hydrogen recycling and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If hydrocracking and hydrotreating units operate at different pressures with separate hydrogen supply systems, then each unit can be optimized for its specific process requirements, but the overall system complexity and capital costs increase
Solution Approach 1:
The patent implements a shared hydrogen supply system where a single make-up hydrogen compressor serves both the hydrocracking unit (higher pressure) and hydrotreating unit (lower pressure) through a common header and pressure control valves. This multi-functional approach allows one compressor to fulfill the hydrogen supply needs of two different pressure zones, reducing capital costs while maintaining process-specific pressure requirements through controlled distribution
Solution Approach 2:
The patent merges the previously separate hydrogen supply systems into a single integrated system. The make-up hydrogen compressor, common header, and associated control infrastructure are combined to serve both hydrocracking and hydrotreating units, eliminating redundant equipment while preserving the ability to deliver appropriate pressures to each unit through valve control
2Productivity
If hydrocracking unit operates at higher pressure to maximize diesel production, then diesel yield increases, but the energy consumption for compression and operating costs increase
Solution Approach 1:
The patent recovers and recycles hydrogen from both the hydrocracking and hydrotreating units back to their respective feed streams. The hydrocracking unit recycle compressor takes hydrogen from the hydrocracking overhead and returns it to the hydrocracking feed, while the hydrotreating unit recycle compressor does the same for the hydrotreating unit. This recycling eliminates the need for continuous make-up hydrogen compression, significantly reducing compression energy consumption while maintaining high diesel production
Solution Approach 2:
The patent implements feedback loops where hydrogen effluent from each unit is compressed and fed back to the respective unit's feed stream. This closed-loop hydrogen recycling system maintains hydrogen inventory and pressure levels without requiring continuous external hydrogen supply, reducing the energy burden of make-up hydrogen compression while sustaining high productivity
3Stress or pressure
If make-up hydrogen is compressed to high pressure for hydrocracking unit, then hydrogen is available for the higher pressure process, but additional compression is needed for the lower pressure hydrotreating unit
Solution Approach 1:
The patent segments the hydrogen distribution system into two distinct pressure zones with separate control mechanisms. A common header receives high-pressure hydrogen from the make-up compressor, then uses pressure control valves to deliver appropriate pressures to each unit: high pressure to the hydrocracking unit and reduced pressure to the hydrotreating unit. This segmentation allows one compressor to serve two different pressure requirements without additional compression equipment
Solution Approach 2:
The patent applies local quality control through pressure control valves positioned at each unit's hydrogen inlet. The hydrocracking unit receives high-pressure hydrogen directly from the common header, while the hydrotreating unit receives lower-pressure hydrogen after passing through a pressure control valve that reduces the pressure locally at that distribution point, eliminating the need for a separate low-pressure compressor
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 enhances diesel production efficiency, ensures compliance with stringent fuel specifications by effectively removing sulfur and nitrogen impurities, and reduces capital and operating costs by integrating hydrocracking and hydrotreating units while optimizing hydrogen use across units.
Implementation Method 1
A first compressor in is communication with the make-up hydrogen line for compressing the make-up hydrogen stream to provide a first compressed make-up hydrogen stream
Implementation Method 2
A second compressor is in communication with the first split line for compressing the first portion of the first compressed make-up hydrogen stream to provide a second compressed make-up hydrogen stream
Data Source
AI summary
An apparatus is disclosed for hydroprocessing two hydrocarbon streams at two different pressures. A hydrogen stream is compressed and split. A first split compressed stream is further compressed to feed a first hydroprocessing unit that requires higher pressure for operation. A second split compressed stream is fed to a second hydroprocessing unit that requires lower pressure. Recycle hydrogen from the second hydroprocessing unit is recycled back to the compression section.