Nickel Catalyst Conditioning for Olefin Trimer Selectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heterogeneous olefin oligomerization processes struggle to increase the selectivity of higher oligomers, particularly trimers, compared to dimers, in the production of C2-C8 olefins.
Innovation Solution
Conditioning a nickel-comprising heterogeneous catalyst with an inert gas stream to reduce the water content below 1000 ppm, allowing for improved monitoring and control, which enhances the formation of olefin trimers and higher oligomers by adjusting the catalyst's conditions before contact with olefins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the catalyst is conditioned by passing an inert gas stream to reduce water content below 1000 ppm, then the selectivity to higher oligomers (trimers and above) is improved, but the complexity of the conditioning process increases
Solution Approach 1:
The catalyst undergoes preliminary conditioning by passing an inert gas stream through it before the actual oligomerization reaction. This preliminary action reduces the water content on the catalyst surface to below 1000 ppm, which prepares the catalyst in an optimal state for achieving high selectivity to higher oligomers during the subsequent reaction.
Solution Approach 2:
The water content parameter of the catalyst is actively controlled and changed during the conditioning phase. By adjusting the inert gas flow and conditioning duration, the water content is reduced to a specific range (below 1000 ppm), which directly influences the catalyst's selectivity toward higher oligomers in the oligomerization reaction.
2Manufacturing precision
If the water content of the catalyst is reduced below 1000 ppm during conditioning, then the formation of linear products is enhanced, but the time required for catalyst preparation increases
Solution Approach 1:
The conditioning process incorporates feedback control by monitoring the water content of the outflowing inert gas stream. This allows the conditioning to be stopped at the optimal point when water content reaches below 1000 ppm, ensuring high linear product selectivity while minimizing unnecessary preparation time.
Solution Approach 2:
The direct measurement of residual water content on the catalyst is replaced by monitoring the water content in the outflowing inert gas stream. This substitution makes the process more controllable and time-efficient, as gas phase water measurement is faster and more practical than direct solid catalyst analysis.
3Productivity
If homogeneous catalysts are used for olefin oligomerization, then the reaction activity is high, but the catalyst separation and regeneration becomes complicated
Solution Approach 1:
A heterogeneous nickel-containing catalyst is used as an intermediary to perform the oligomerization function that homogeneous catalysts provide. The solid catalyst particles remain in the reactor while the liquid or gaseous olefin products flow through, enabling easy separation without complex work-up procedures while maintaining high reaction activity.
Solution Approach 2:
The use of a heterogeneous catalyst creates an inert physical environment where the catalyst remains as solid particles unaffected by the reaction mixture. This allows the reaction to proceed with high activity while the catalyst can be easily separated by simple filtration or decantation, avoiding complicated separation and regeneration steps required for homogeneous catalysts.
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
The process increases the weight ratio of olefin trimers and higher oligomers to dimers, achieving selectivity greater than 0.2, with catalysts comprising nickel oxide, titanium dioxide, and silicon dioxide, resulting in increased production of linear products like octenes and dodecenes.
Implementation Method 1
a nickel-comprising heterogeneous catalyst, wherein the catalyst is conditioned by passing an inert gas stream over it
Implementation Method 2
the catalyst is conditioned by passing an inert gas stream over it until the outflowing inert gas stream has a water content of less than 1000 ppm
Data Source
AI summary
Olefins are oligomerized by bringing at least one C2 to C8-olefin into contact with a nickel-containing heterogeneous catalyst. The catalyst is conditioned before contact with the olefin by passing an inert gas flow over the same, until the inert gas flow has a water content of less than 1000 ppm. Selectivity for the production of higher oligomers, in particular trimers relative to the formation of dimers is increased by the pretreatment.