Slurry Hydrocracking Reactor Clogging Prevention via Pyrolysis Oil Temperature Control
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Solution Overview
Problem
The co-processing of biomass-derived pyrolysis oil with hydrocarbon feedstocks in slurry hydrocracking reactors is hindered by catalyst fouling and rapid clogging due to thermal or acid-catalyzed polymerization of unstable components, leading to maintenance stops and inefficient processability.
Innovation Solution
Maintaining pyrolysis oil at a temperature below 100°C until it contacts the hydrocarbon feedstock and hydrocracking catalyst, thereby minimizing secondary polymerization reactions and reducing clogging, while allowing primary cracking and deoxygenation reactions to proceed at higher rates within the reactor's elevated temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pyrolysis oil is heated to high temperature before contacting the catalyst, then primary cracking and deoxygenation reactions proceed faster, but secondary polymerization reactions increase causing rapid clogging and fouling of the reactor
Solution Approach 1:
The pyrolysis oil is pre-heated to a temperature below 100°C in advance to reduce its viscosity and improve flowability, but this preliminary heating is intentionally limited to prevent secondary polymerization reactions that would cause clogging. The oil is then quickly introduced to the high-temperature catalyst bed where primary reactions occur rapidly.
Solution Approach 2:
The invention changes the temperature parameter dynamically: the pyrolysis oil is maintained at low temperature (<100°C) during transport and mixing to prevent polymerization, then rapidly heated to high temperature (300-400°C) upon contact with the catalyst bed to enable fast primary cracking and deoxygenation reactions.
2Reliability
If pyrolysis oil is mixed with hydrocarbon feedstock and catalyst at low temperature, then clogging is reduced, but reaction rates decrease
Solution Approach 1:
The invention utilizes phase transition and rapid heating: the cold pyrolysis oil (<100°C) is mixed with hydrocarbon feedstock and catalyst, then the mixture is rapidly heated to reaction temperature (300-400°C) upon entering the reactor, causing quick phase changes that enable fast reaction rates while avoiding prolonged exposure to temperatures that would cause polymerization.
Solution Approach 2:
The low-temperature mixing and high-temperature reaction are continuous processes. The pyrolysis oil is continuously fed at low temperature to prevent clogging, then continuously and rapidly heated to reaction temperature in the catalyst bed, maintaining continuous productive action without interruption from clogging events.
3Loss of substance
If catalytic deoxygenation is performed on pyrolysis oil, then oxygen content is reduced, but catalyst fouling and rapid plugging occur
Solution Approach 1:
The hydrocarbon feedstock acts as an intermediary medium. The pyrolysis oil is mixed with hydrocarbon feedstock and catalyst together at low temperature, forming a homogeneous slurry that prevents localized overheating and hot spots that would cause polymerization and catalyst fouling, while still enabling effective catalytic deoxygenation.
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 significantly reduces reactor clogging and increases production efficiency by controlling reaction rates, enabling the efficient co-processing of hydrocarbon and biorenewable feedstocks in existing slurry hydrocracking infrastructure.
Implementation Method 1
thermal or acid catalysed polymerization of at least a portion of the hydrogen-deficient and chemically unstable components present in the biomass-derived pyrolysis oil
Implementation Method 2
the hydrocarbon feedstock, such as petroleum derived feedstock, and the pyrolysis oil are hydrocracked in the slurry hydrocracking reactor in the presence of the hydrocracking catalyst and hydrogen gas
Implementation Method 3
the hydrocarbon feedstock, such as petroleum derived feedstock, and the pyrolysis oil are hydrocracked in the slurry hydrocracking reactor in the presence of the hydrocracking catalyst and hydrogen gas
Data Source
AI summary
A process of producing a hydrocracking product in a slurry hydrocracking reactor. A pyrolysis oil, a hydrocarbon feedstock, and a hydrocracking catalyst is provided. The pyrolysis oil is combined with the hydrocarbon feedstock and the hydrocracking catalyst, the pyrolysis oil being maintained at a temperature of less than 100° C. until the pyrolysis oil contacts both the hydrocarbon feedstock and the hydrocracking catalyst. The hydrocarbon feedstock and the pyrolysis oil are hydrocracked in the slurry hydrocracking reactor in the presence of the hydrocracking catalyst and hydrogen gas. A fuel precursor obtainable by the process.