Oligomerization Reactor Temperature Control via Effluent Recycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing jet-range hydrocarbons from biorenewable sources face challenges in efficiently controlling temperature rise during oligomerization reactions, which limits processing efficiency due to the need for excessive dilution with inert materials.
Innovation Solution
The process involves splitting a renewable olefin feedstock into multiple streams, with each stream being passed to separate reactors, where the effluent from an upstream reactor is used to dilute the feedstock to a downstream reactor, allowing for more effective temperature control and increased processing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If non-reactive diluent material is added to control temperature rise in oligomerization reactors, then temperature control is improved, but processing efficiency decreases due to excessive dilution requirements
Solution Approach 1:
The patent recycles the effluent stream from the oligomerization reactor back to the reactor inlet, transforming what would be waste material into a useful diluent. This recovered effluent contains unreacted olefins and reaction products that serve as effective heat sinks for temperature control, eliminating the need for excessive inert diluent addition while maintaining processing efficiency
Solution Approach 2:
The effluent stream acts as an intermediary substance that mediates between the exothermic oligomerization reaction and temperature control requirements. By introducing this intermediate stream into the reactor, the system achieves thermal management without relying on large amounts of inert diluent material, thus resolving the contradiction between temperature control and processing efficiency
2Temperature
If the proportion of olefins in the feedstream is limited to no more than 15 wt% to control temperature increase, then temperature rise is controlled, but processing yield decreases
Solution Approach 1:
The patent changes the composition parameter of the feedstream by incorporating recycled effluent, which has a different olefin concentration than the fresh feed. This parameter change allows the system to maintain lower instantaneous olefin proportions for temperature control while still processing higher overall quantities of olefins, thereby increasing processing yield without excessive temperature rise
Solution Approach 2:
The continuous recycling of effluent creates a continuous flow of diluted olefin mixture into the reactor, maintaining steady-state temperature control while continuously processing olefin feedstock. This continuous action eliminates the need to limit fresh feed olefin content, as the recycled stream continuously provides the necessary dilution effect
3Temperature
If excessive dilution with inert materials is used to control oligomerization temperature, then temperature control is improved, but energy costs increase
Solution Approach 1:
The system uses its own effluent stream to provide the dilution function, making the system self-sufficient for temperature control. The effluent, which would otherwise be waste requiring energy-intensive separation and disposal, serves as the diluent, eliminating the need for external inert materials and reducing energy costs associated with their production, handling, and disposal
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 processing yield and reduces energy costs by minimizing the need for inert diluents, while maintaining comparable production levels, and allows for the production of jet-range hydrocarbons from biorenewable sources.
Implementation Method 1
an effluent from an upstream reactor is used to dilute the stream of renewable olefin feedstock to a downstream reactor
Implementation Method 2
Since the oligomerization reaction is highly exothermic, the butene fed to the oligomerization reactors may be cooled before entering the oligomerization reactors
Implementation Method 3
The butenes are then oligomerized, in the presence of an oligomerization catalyst, in one or more reactors to form heavier olefins
Implementation Method 4
the resulting olefinic oligomers are hydrogenated in a saturation reactor to form the corresponding C5 to C20, or even higher, paraffins
Data Source
AI summary
Processes for producing jet-range hydrocarbons includes splitting a renewable olefin feedstock comprising C3 to C8 olefins into a plurality of streams and passing each stream to an oligomerization reactor containing a zeolite catalyst to produce an oligomerized effluent. The reactors may be arranged in series, such that an oligomerized effluent comprises a diluent for a downstream reactor. The net oligomerized effluent may be separated and a heavy olefin stream comprising C8+ olefins may be hydrogenated and separated to provide a distillate range hydrocarbon product.