Pyrolysis Oil Upgrading via Segmented Hydrodeoxygenation and Pre-Reforming
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Solution Overview
Problem
Pyrolysis oils are chemically and thermally unstable, leading to phase separation and coking issues during steam reforming, limiting their valorization in refineries, and high hydrogen consumption in hydrodeoxygenation processes hinders sustainability goals.
Innovation Solution
A process involving hydrodeoxygenation followed by pre-reforming of the aqueous fraction and hydrotreatment/catalytic cracking of the lignin-rich fraction to produce hydrogen and fuel bases, reducing hydrogen consumption and coking problems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If pyrolysis oil is directly used in refinery applications, then the process is simple, but the oil's chemical and thermal instability causes phase separation and coking
Solution Approach 1:
The patent applies preliminary action by performing stabilization treatment on pyrolysis oil before refinery processing. The oil undergoes hydrodeoxygenation and catalytic cracking in advance to eliminate reactive species, prevent phase separation, and remove coking precursors, ensuring stable operation in downstream refinery units.
Solution Approach 2:
The patent converts the harmful high oxygen content (40-60% m/m) and chemical instability of pyrolysis oil into beneficial outcomes. Through hydrodeoxygenation, the excess oxygen is removed as water, stabilizing the oil. The same unstable reactive species that cause coking are transformed into stable hydrocarbon products through catalytic cracking, turning potential problems into quality improvements.
2Reliability
If hydrodeoxygenation is performed to stabilize pyrolysis oil, then oil stability improves, but hydrogen consumption increases significantly
Solution Approach 1:
The patent segments the stabilization process into two distinct stages: first, hydrodeoxygenation to remove excess oxygen and achieve basic stability; second, catalytic cracking to remove remaining reactive species and coking precursors. This segmentation allows optimized hydrogen usage in each stage rather than requiring excessive hydrogen for complete stabilization in a single step.
Solution Approach 2:
The patent employs parameter changes by conducting hydrodeoxygenation at moderate temperatures (150-350°C) and pressures (100-200 bars), then performing catalytic cracking at higher temperatures (400-600°C) with catalysts. These parameter optimizations reduce the total hydrogen requirement compared to conventional high-pressure hydrodeoxygenation alone, while achieving complete stabilization.
3Quantity of substance
If steam reforming is applied to pyrolysis oil to produce hydrogen, then hydrogen production increases, but coking problems worsen due to oil instability
Solution Approach 1:
The patent applies preliminary stabilization through hydrodeoxygenation and catalytic cracking before steam reforming. This preliminary action removes reactive oxygenated compounds and coking precursors from the pyrolysis oil, creating a stabilized feedstock that resists coking during the high-temperature steam reforming process, thereby enabling sustained hydrogen production.
4Adaptability or versatility
If pyrolysis oil is stabilized through extensive treatment to enable refinery use, then oil compatibility improves, but processing cost increases
Solution Approach 1:
The patent segments the stabilization process into two optimized stages: hydrodeoxygenation to achieve basic stability and partial deoxygenation, followed by catalytic cracking to enhance compatibility with hydrocarbons. This segmentation allows flexible operation where the extent of each stage can be adjusted based on the desired level of miscibility, optimizing processing costs for different application requirements.
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
Enables the complete valorization of pyrolysis oils by producing hydrogen and fuel bases while minimizing hydrogen external supply and avoiding coking, thus aligning with sustainability criteria.
Implementation Method 1
a hydrodeoxygenation unit (HDO) (10), characterised in that it is followed by a pre-reforming unit (22) for treating a light aqueous fraction
Implementation Method 2
a pre-reforming unit (22) for treating a light aqueous fraction
Implementation Method 3
an SMR unit (28) for producing hydrogen
Implementation Method 4
a hydrotreatment unit (40) for treating a heavy organic fraction
Implementation Method 5
hydrotreatment and/or catalytic cracking and/or visbreaking of said lignin-rich fraction
Data Source
AI summary
The invention relates to a process for upgrading a pyrolysis oil comprising the following steps: - hydrodeoxygenation treatment (10) of the pyrolysis oil (12) and separation of the effluent (16) obtained into a light aqueous fraction (18) and a heavy organic fraction (20), or separation of the pyrolysis oil into an aqueous fraction and a lignin-rich fraction, - pre-reforming (22) of said aqueous fraction (18) and treatment of the effluent (26) obtained in an SMR unit (28) in order to produce hydrogen (34), - hydrotreatment (40) and/or catalytic cracking and/or visbreaking of said heavy organic fraction (20).