Biofeed Hydroprocessing with Vapor Contact for Higher Jet Fuel Yield
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Solution Overview
Problem
Existing processes for producing jet fuel from biorenewable feedstocks face challenges in achieving high yield while meeting jet fuel specifications, particularly due to the high concentration of nC16 hydrocarbons affecting the freeze point, leading to inefficiencies and yield loss.
Innovation Solution
A process involving hydrotreating followed by hydroisomerization, including a hot separator to separate vapor and liquid streams, and a hydroisomerization reactor with a specific catalyst, combined with a cold separator to absorb heavier components, reduces nC16 hydrocarbon carryover, improving jet fuel yield and meeting freeze point specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If hydrocracking is performed to meet jet fuel specifications, then freeze point and molecular weight specifications are satisfied, but jet fuel yield decreases
Solution Approach 1:
The patent changes the operating parameters of the hydroisomerization reactor, specifically operating at lower severity conditions (lower temperature, lower pressure, shorter residence time) compared to conventional high-severity operations. This parameter change allows the process to meet jet fuel specifications while minimizing yield loss by reducing excessive hydrocracking reactions.
2Manufacturing precision
If hydroisomerization severity is increased to meet freeze point specifications, then jet fuel freeze point requirement is satisfied, but jet fuel yield loss increases
Solution Approach 1:
The patent optimizes the hydroisomerization reactor operating parameters to achieve the minimum required isomerization activity to meet freeze point specifications without excessive severity. By carefully controlling temperature, pressure, and residence time, the process achieves specification compliance while minimizing yield loss.
3Manufacturing precision
If hydrocracking is performed to reduce heavy molecules, then jet fuel molecular weight and boiling point specifications are met, but overall process yield decreases
Solution Approach 1:
The patent employs milder hydrocracking conditions by operating the hydroisomerization reactor at lower severity, which reduces the extent of molecular weight reduction while still achieving specification compliance. This selective parameter change preserves more feedstock as usable jet fuel product.
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 jet fuel yield by 0.7 to 1 wt% and ensures the produced jet fuel meets freeze point specifications by minimizing nC16 hydrocarbon carryover, thereby improving cold flow properties and overall efficiency.
Implementation Method 1
hydroisomerized in a hydroisomerization reactor in the presence of hydrogen over a hydroisomerization catalyst
Implementation Method 2
separating the hydrotreated stream in a hot separator into a hot separated vapor stream and a hot separated liquid stream
Implementation Method 3
contacting the hydroisomerized stream with a recycle vapor stream taken from the hot separated vapor stream
Data Source
AI summary
A process for producing biofuel from biorenewable feedstock is disclosed. The process comprises hydrotreating a biorenewable feed stream in a hydrotreating reactor to produce a hydrotreated stream. The hydrotreated stream is separated in a hot separator into a hot separated vapor stream and a hot separated liquid stream. A hydroisomerization feed stream is taken from the hot separated liquid stream and hydroisomerized in a hydroisomerization reactor in the presence of hydrogen over a hydroisomerization catalyst to provide a hydroisomerized stream. The hydroisomerized stream is contacted with a recycle vapor stream taken from the hot separated vapor stream to provide a contacted hydroisomerized stream. The contacted hydroisomerized stream may be fractionated to produce a fuel stream.