Hydroisomerisation-Hydrocracking Process for Higher Aviation Fuel Yield
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Solution Overview
Problem
Existing processes for producing aviation fuel components from renewable raw materials have low yield and quality, and there is a need to reduce the formation of C1-C4 hydrocarbons, especially C1-C2 hydrocarbons, while prolonging the lifetime of hydroisomerization catalysts.
Innovation Solution
A process involving hydroisomerization of a paraffinic hydrocarbon feed with at least 60 wt-% paraffins and up to 30 wt-% isoparaffins, followed by hydrocracking and fractionation, to produce high-quality aviation fuel components with a high isoparaffin content and reduced low-profit products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydroisomerisation processes are used to produce aviation fuel components from renewable raw materials, then the process is simpler and uses standard catalysts, but the yield of aviation fuel components is low and the quality is insufficient
Solution Approach 1:
The process is divided into two distinct stages: first hydroisomerisation to convert n-paraffins to iso-paraffins, then hydrocracking to produce aviation fuel components. This segmentation allows each stage to be optimized independently, with the first stage focusing on isomerisation and the second on cracking, thereby increasing overall yield and quality of aviation fuel components
Solution Approach 2:
Hydroisomerisation is performed as a preliminary step before hydrocracking to pre-isomerise the paraffinic feedstock. This preliminary action of converting n-paraffins to iso-paraffins before cracking improves the quality and yield of the final aviation fuel components by ensuring the feed to the cracker is already highly isomerised
2Manufacturing precision
If hydroisomerisation is performed to increase isoparaffin content, then the quality of fuel component improves, but C1-C4 hydrocarbon formation increases and catalyst lifetime decreases
Solution Approach 1:
The harmful effect of excessive C1-C4 hydrocarbon formation and catalyst deactivation is separated from the useful isomerisation process by using two different catalysts in sequence. The first catalyst is optimized for isomerisation with minimal cracking activity, while the second catalyst handles the cracking function, thereby protecting the isomerisation catalyst from deactivation and reducing light gas formation
Solution Approach 2:
The hydroisomerisation effluent acts as an intermediary between the isomerisation and hydrocracking stages. By fully isomerising the feed in the first stage before introducing it to the second catalyst, the intermediary stream ensures that the hydrocracking stage receives optimally prepared feed, reducing the burden on the second catalyst and minimizing unwanted side reactions
3Ease of manufacture
If paraffinic feed with high n-paraffin content is used, then the feedstock is readily available and simpler to process, but the cold properties and fluidity of the resulting fuel are inferior
Solution Approach 1:
The molecular structure parameter of the fuel is changed by converting n-paraffins to iso-paraffins through hydroisomerisation. This parameter change increases branching in the hydrocarbon molecules, which directly improves cold properties and fluidity of the fuel while maintaining compatibility with readily available n-paraffinic feedstocks
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 enhances the yield and quality of aviation fuel components, particularly by converting highly isomerized paraffins into valuable fuel components in the aviation fuel range with improved cold properties and extended catalyst lifetime.
Implementation Method 1
subjecting the paraffinic hydrocarbon feed in a first reactor to hydroisomerisation in the presence of a hydroisomerisation catalyst to obtain a hydroisomerisation effluent comprising at least 50 wt-% isoparaffins of the total weight of paraffins in the hydroisomerisation effluent
Implementation Method 2
subjecting a second reactor feed comprising the hydroisomerisation effluent to hydrocracking in a second reactor in the presence of a hydrocracking catalyst to obtain a hydrocracking effluent
Implementation Method 3
subjecting the hydrocracking effluent to fractionation, and recovering from the fractionation at least one or more liquid transportation fuel components
Data Source
AI summary
A process for producing at least one liquid transportation fuel component is provided. In the process, a paraffinic hydrocarbon feed is provided and subjected to hydroisomerisation to obtain a hydroisomerisation effluent; which hydroisomerisation effluent is subjected to hydrocracking to obtain a hydrocracking effluent, the hydrocracking effluent being fed to fractionation from which fractionation at least one liquid transportation fuel component is recovered.