Renewable Feedstock Filtration in Hydroprocessing Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hydroprocessing of renewable feedstocks faces challenges such as high exothermicity, fouling, and particulate matter issues, leading to increased costs and reduced energy efficiency, as well as catalyst deactivation and pressure drop across catalyst beds.
Innovation Solution
A process involving a fixed-bed reactor system with a filtering zone and a catalytic zone, where the renewable feedstock is filtered to capture fouling and particulate matter before reacting in the catalytic zone, and a grading zone is used to manage exothermicity and protect the catalyst.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high liquid recycle rate and liquid quench are applied to control exothermicity, then temperature increase is controlled, but equipment size and hydraulic load increase
Solution Approach 1:
The feedstock is preheated in a heat exchanger using the hot product stream before entering the reactor. This preliminary heating action allows the reaction mixture to enter at an optimized temperature, reducing the temperature spike from exothermic reactions without requiring excessive recycle streams or quench equipment.
Solution Approach 2:
A thermal coupling is introduced where the hot product stream serves as an intermediary heat transfer medium. This mediator transfers thermal energy from the product to the feedstock in the heat exchanger, enabling temperature control through heat integration rather than through equipment size increases.
2Temperature
If preheating renewable feedstock is performed before introduction to reactor, then reaction temperature is achieved, but fouling of catalyst bed increases
Solution Approach 1:
The feedstock undergoes preliminary filtration through a filter press before entering the reactor. This pre-action removes particulate matter and potential fouling agents from the feedstock, preventing them from depositing on the catalyst bed during the heated reaction process.
Solution Approach 2:
A sacrificial filter press is employed that can be easily replaced or regenerated. This disposable-like filtering component protects the expensive catalyst from fouling by capturing particulates in the feedstock, and can be maintained independently without affecting the catalyst.
3Duration of action of stationary object
If filtration is performed to remove fouling and particulate matter, then catalyst life is extended, but pressure drop increases
Solution Approach 1:
Filtration is performed preliminarily in a filter press before the feedstock enters the reactor. By removing particulate matter and fouling agents before reaction, the catalyst is protected from deactivation, extending its operational life without requiring continuous filtration during the reaction that would cause pressure drop.
Solution Approach 2:
The filtration function is segmented into a separate pre-treatment unit (filter press) distinct from the reaction system. This segmentation allows filtration to occur independently before the feedstock enters the reactor, preventing pressure drop issues that would arise from incorporating filtration directly into the reaction system.
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 process improves cost effectiveness, energy efficiency, and catalyst life by reducing fouling and pressure drop, while effectively managing exothermic reactions and extending catalyst activity.
Implementation Method 1
passing the downward flow from the interstitial portions to the annular portions through a filtering material disposed between the interstitial portions and the annular portions
Implementation Method 2
reacting the filtered feedstock in the catalytic zone under hydroprocessing conditions sufficient to cause a reaction selected from the group consisting of hydrogenation, hydrodeoxygenation, hydrodenitrogenation, hydrodesulphurization, hydrodemetalation, hydrocracking, hydroisomerization
Implementation Method 3
Hydrogenation of unsaturated compounds, such as diolefins, is highly exothermic. Hydrodeoxygenation is also an exothermic reaction
Data Source
AI summary
A process for hydroprocessing a renewable feedstock in a fixed-bed reactor system having at least one catalytic bed involves directing a downward flow of the renewable feedstock to a filtering zone having top-open interstitial portions to receive the downward flow and top-covered annular portions that are in fluid communication with a headspace between the filtering zone and a catalytic zone. The feedstock flows from the interstitial portions to the annular portions through a filtering material disposed between the interstitial portions and the annular portions, resulting in a filtered feedstock, which then flows to the catalytic zone. In the catalytic zone, filtered feedstock is reacted under hydroprocessing conditions sufficient to cause a reaction selected from the group consisting of hydrogenation, hydrodeoxygenation, hydrodenitrogenation, hydrodesulphurization, hydrodemetalation, hydrocracking, hydroisomerization, and combinations thereof.