Two-Stage Biocomponent Hydroprocessing for Diesel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydroprocessing of biocomponent feeds for diesel fuel production is costly due to high hydrogen consumption and generates CO and CO2, which pose challenges for hydrogen recycling and equipment corrosion, and requires large excess hydrogen, leading to inefficient processing and equipment maintenance issues.
Innovation Solution
A method involving a two-stage process where a mineral feedstock is hydrotreated in a continuous gas phase followed by deoxygenation of a biocomponent feed in a continuous liquid phase, with hydrogen management to maintain a stable hydrogen need, reducing the need for excess hydrogen and minimizing CO and CO2 production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydroprocessing is used to process biocomponent feeds, then diesel fuel can be produced, but hydrogen consumption exceeds 1000 scf/bbl and CO/CO2 production occurs
Solution Approach 1:
The hydroprocessing process is divided into multiple sequential reactor stages (first stage, second stage, third stage, etc.), where each stage performs specific functions. The biocomponent feed is processed in later stages after mineral feed is processed in earlier stages, allowing for optimized hydrogen utilization and reduced overall hydrogen consumption while maintaining diesel fuel production efficiency.
Solution Approach 2:
The process changes the phase environment parameter from traditional continuous gas phase to continuous liquid phase in later reactor stages. This parameter change allows for better hydrogen solubility and utilization, reducing the excessive hydrogen consumption (above 1000 scf/bbl) associated with conventional hydroprocessing while still producing diesel fuel effectively.
2Productivity
If large amounts of excess hydrogen are used for biocomponent feed processing, then hydroprocessing can proceed, but CO and CO2 are produced which cause equipment corrosion and hydrogen recycling difficulties
Solution Approach 1:
The processing is segmented into stages where mineral feed is processed first in gas-continuous stages, and biocomponent feed is processed in subsequent liquid-continuous stages. This segmentation allows for controlled reactions that minimize CO and CO2 generation while maintaining processing productivity, and the separated stage design facilitates easier management of harmful byproducts.
Solution Approach 2:
The process utilizes phase transition from gas-continuous environment in early stages to liquid-continuous environment in later stages. This phase transition changes the reaction conditions to reduce CO and CO2 production from biocomponent feed processing, thereby reducing equipment corrosion and simplifying hydrogen recycling while maintaining processing efficiency.
3Productivity
If conventional hydroprocessing equipment is used for biocomponent feeds, then processing can be performed, but the process is expensive from a refinery perspective
Solution Approach 1:
The refinery process is segmented to handle mineral and biocomponent feeds through different stage sequences. This segmentation allows for optimized resource utilization, reduced hydrogen consumption, and minimized harmful byproduct treatment requirements, thereby reducing overall processing costs while maintaining diesel fuel production capability.
Solution Approach 2:
The multi-stage reactor system serves multiple functions: it processes both mineral and biocomponent feeds, performs hydrotreating and deoxygenation in different stages, and optimizes hydrogen utilization across the entire process. This multi-functionality reduces the need for separate dedicated processing lines, lowering capital and operating costs while maintaining high productivity for biocomponent feed processing.
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 reduces hydrogen consumption, minimizes the need for hydrogen recycling, and mitigates equipment corrosion, resulting in more efficient and cost-effective diesel fuel production while maintaining product quality.
Implementation Method 1
contacting a mineral feedstock having a sulfur content of at least about 500 wppm with a hydrotreating catalyst under effective hydrotreating conditions in a hydrotreatment reactor that includes a continuous gas phase to make a hydrotreated effluent
Implementation Method 2
U.S. Pat. No. 7,291,257 describes a system and method for two phase hydroprocessing of a mineral feed. The method is described as allowing for hydroprocessing where the need to circulate hydrogen gas or a separate hydrogen phase through the catalyst is eliminated. Instead, the hydrogen for the hydroprocessing is dissolved in the feed
Implementation Method 3
deoxygenating the mixed input stream under effective deoxygenation conditions in a deoxygenation stage having a continuous liquid phase environment to form a second diesel boiling range product
Data Source
AI summary
A mineral feed can be hydrotreated in a trickle-bed reactor or other stage in a continuous gas-phase environment. The effluent from the hydrotreatment stage can be separated to remove gas-phase impurities. The remaining liquid effluent from the hydrotreating stage can then be introduced, in total or in part, into a second stage/reactor. A feed of biocomponent origin can also be introduced into the second stage/reactor. The second stage/reactor can be operated to perform deoxygenation of the mixture of biocomponent feed and hydrotreated liquid effluent in a continuous liquid phase environment.