Olefin Oligomerization Process with Segmented Reactor-Column Stages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing olefin oligomerization processes face challenges with low olefin concentrations and high inert components, leading to inefficient operations and increased costs due to the design limitations of existing plants, particularly when using naphtha as a raw material, which is being replaced by cheaper ethane from shale gas.
Innovation Solution
A process involving at least three reaction stages connected in series, with each stage comprising a reactor and a distillation column, where the feed mixture is divided to optimize olefin distribution, using a nickel compound on an aluminosilicate support catalyst with minimal titanium dioxide and zirconium dioxide, and operating the final reactor adiabatically to manage heat and energy efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the feed mixture is processed in conventional single-stage or two-stage oligomerization processes, then the existing plant design can be used, but the throughput is insufficient and economically problematic at low olefin concentrations
Solution Approach 1:
The oligomerization process is divided into at least three consecutive reaction stages, each with its own reactor and distillation column. This segmentation allows each stage to be optimized for specific olefin concentration ranges, maintaining high throughput even when feed olefin content is low. The multi-stage configuration enables progressive oligomerization while managing heat release and inert component accumulation in each stage separately.
2Quantity of substance
If integrated distillation columns are used to separate oligomers, then product separation is achieved, but the columns reach hydrodynamic limits when non-oligomerizable inert components become too high
Solution Approach 1:
The distillation process is segmented into multiple independent columns, each associated with a specific reaction stage. This allows the overhead product from each column to be selectively fed to subsequent reaction stages with appropriate olefin concentrations, preventing inert component accumulation that would otherwise reach hydrodynamic limits in a single integrated column.
Solution Approach 2:
The overhead products from each distillation column act as intermediaries that are selectively directed to appropriate reaction stages. This intermediary approach allows optimization of olefin distribution across stages, ensuring that stages receiving feeds with lower olefin content (which would otherwise overload the distillation system) are properly managed.
3Adaptability or versatility
If high proportions of non-oligomerizable inert components such as alkanes are present in the feed, then the process can handle diverse feedstocks, but energy consumption increases negatively
Solution Approach 1:
The multi-stage reaction and distillation configuration segments the processing of inert components across different stages. Each stage handles a portion of the inert load, and the overhead products are selectively distributed to subsequent stages. This segmentation prevents the accumulation of inert components in a single stage, reducing the energy required for heating and distillation compared to processing the entire feedstock in one stage.
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 significantly enhances the utilization of olefins, maintaining high conversions and space-time yields even at low olefin contents, preventing economically problematic scenarios and optimizing energy use by recycling heat and adjusting feed streams to maintain efficient oligomerization.
Implementation Method 1
Oligomerization of the olefins in the feed stream to the first reaction stage in at least one reactor using an oligomerization catalyst
Implementation Method 2
separation of the oligomers formed as bottoms product in a subsequent distillation column
Implementation Method 3
the reactors in the previous reaction stages are cooled using a cooling medium
Implementation Method 4
the reactor or reactors in the last reaction stage are operated adiabatically
Data Source
Figure 1
AI summary
The present invention relates to a process for the oligomerization of C2 to C8 olefins in several reaction stages, in which the feed mixture and the respective discharges from the reaction stages are separated and fed to different reaction stages.