Hydration-Oligomerization Segmentation for C4 Alcohol Selectivity
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Solution Overview
Problem
The existing processes for oligomerization of light olefins face challenges in maintaining precise control over the water-to-isobutene mole ratio, leading to non-uniform reaction environments and catalyst deactivation, which limits the selectivity of dimer products and increases the formation of undesired trimer products, while also requiring energy-intensive and costly separation methods for tert-butyl alcohol (TBA).
Innovation Solution
Dividing the olefinic C4 feedstock into two streams and processing them through separate hydration and oligomerization reaction zones using acidic catalysts, including ion exchange resin, where TBA is produced in situ in the hydration zone and precisely quantified for the oligomerization zone, minimizing water carryover and impurities, and utilizing a DeMet reaction zone to remove impurities, thereby maintaining independent control over reaction conditions and catalyst performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If water is added to isobutene in a single reactor to produce TBA in situ, then the selectivity of dimer product is improved, but the reaction environment becomes non-uniform and catalyst deactivation occurs
Solution Approach 1:
The single reactor system is divided into two separate reactors: a first reactor dedicated to hydration reaction (producing TBA) and a second reactor dedicated to oligomerization reaction. This segmentation allows each reactor to maintain uniform reaction conditions appropriate for its specific function, preventing catalyst deactivation while achieving high dimer selectivity.
2Manufacturing precision
If water to isobutene mole ratio is maintained less than 0.06, then dimerization reaction is suppressed, but selectivity of dimer product cannot be increased beyond 73%
Solution Approach 1:
The process separates hydration and oligomerization into distinct reactors, allowing the first reactor to operate with higher water to isobutene ratios (0.06-0.5) to produce TBA without suppressing dimerization, while the second reactor maintains optimal conditions for oligomerization. This enables both high dimer selectivity and maintained productivity.
3Manufacturing precision
If precise dosing of water is performed to maintain low water to isobutene ratio, then dimerization selectivity is improved, but operation becomes difficult and temperature profile becomes non-uniform
Solution Approach 1:
By separating the hydration function into a dedicated first reactor, the system eliminates the need for precise water dosing control in the oligomerization reactor. The first reactor can operate with more flexible water addition (0.06-0.5 mole ratio) to produce TBA, which then flows to the second reactor, simplifying overall operation while maintaining uniform temperature profiles.
4Quantity of substance
If energy-intensive separation methods like extraction and dual distillation are used to recover TBA, then TBA recovery is achieved, but energy consumption and cost increase
Solution Approach 1:
The system uses the reaction heat from the highly exothermic oligomerization reaction in the second reactor to provide the necessary heat for TBA separation and purification. This self-service approach eliminates or reduces the need for external energy-intensive separation methods like extraction and dual distillation, achieving TBA recovery with minimal additional energy consumption.
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 allows for high selectivity of dimer products (>90%) while avoiding catalyst deactivation, reducing energy and costs, and enabling flexible operation of reaction zones, ensuring uniform product distribution and extended catalyst life.
Implementation Method 1
passing the first stream (5) through a hydration reaction zone (7), wherein, an acidic catalyst and water (6) hydrate an olefinic C4 feedstock of the first stream (5) into heavier products including a mixture of a plurality of alcohol compounds
Implementation Method 2
passing the second stream (4) through an oligomerization reaction zone (15) in the presence an ion exchange resin catalyst, wherein, the second stream (4) converts an olefinic C4 feedstock of the second stream (4) into an oligomer compound
Implementation Method 3
passing the olefinic C4 feedstock (1) through a de-metallization reaction zone (2), wherein, the de-metallization reaction zone (2) removes at least one impurity component from the said olefinic C4 feedstock (1). The at least one impurity component is selected from a metal impurity component such as iron, calcium, sodium ionic components
Data Source
AI summary
The present invention discloses an integrated process and an apparatus for production of various alcohols and Oligomerization of Olefinic feed stocks comprising butylenes and mixture thereof. In this process the combined light olefinic hydrocarbon feedstock is divided into two streams and contacted in two different reaction zones, viz. hydration and oligomerization. The mixture of alcohols and oligomer product from hydration reaction is separated and the bottom stream from separator is routed to oligomerization reaction zone in a controlled quantity as selectivity enhancer. Both the reaction zones are operated at different conditions. The product from oligomerization zone is further separated in to lighter and heavier components. Each reaction zone may comprise series of reactors filled with acidic catalysts comprising ion exchange resins.