Hydroisomerization Catalysts for Diesel Cold Flow

Solution Overview

Problem

Unconventional feedstocks like biocomponent feeds and Fischer-Tropsch feeds exhibit poor cold flow properties, leading to issues such as fuel filter blocking in cold conditions, and conventional methods to improve these properties are costly and inefficient, reducing diesel fuel yield.

Innovation Solution

A process involving hydroisomerization using a catalyst comprising zeolite SSZ-91, SSZ-32, or SSZ-32x to reduce the cloud and pour points of diesel fuel, thereby enhancing its cold flow properties without yield reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional additives are used to decrease cloud point and pour point, then cold flow properties are improved, but manufacturing cost increases and diesel fuel yield reduces

Engineering Contradiction:

Improvecold flow propertiesVSAvoiddiesel fuel yield

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The invention changes the molecular structure parameters of diesel components through hydroisomerization, converting straight-chain paraffins into branched isomers with lower cloud and pour points. This structural transformation improves cold flow properties inherently without requiring additives, thereby maintaining high diesel fuel yield while achieving reliable cold flow performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical/additive-based approach (adding cold flow improvement additives) with a chemical/catalytic approach (hydroisomerization using zeolite catalysts). This substitution transforms the method of improving cold flow properties from external addition to internal molecular restructuring, eliminating yield reduction and cost increases associated with additives.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional additives are used to decrease cloud point and pour point, then cold flow properties are improved, but manufacturing cost increases

Engineering Contradiction:

Improvecold flow propertiesVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the molecular structure parameters of diesel components through hydroisomerization, converting straight-chain paraffins into branched isomers with lower cloud and pour points. This structural transformation improves cold flow properties inherently without requiring additives, thereby maintaining high diesel fuel yield while achieving reliable cold flow performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical/additive-based approach (adding cold flow improvement additives) with a chemical/catalytic approach (hydroisomerization using zeolite catalysts). This substitution transforms the method of improving cold flow properties from external addition to internal molecular restructuring, eliminating yield reduction and cost increases associated with additives.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If hydroisomerization with zeolite catalyst is used, then diesel fuel yield is maintained high and cold flow properties are improved, but process complexity increases

Engineering Contradiction:

Improvediesel fuel yieldVSAvoidprocess complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention employs composite catalyst systems combining zeolite SSZ-91, SSZ-32, or SSZ-32x with appropriate metal components. These composite catalysts provide synergistic effects that enhance hydroisomerization activity and selectivity, enabling high diesel fuel yield and improved cold flow properties through a single integrated process rather than multiple sequential steps.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The zeolite-based hydroisomerization catalyst performs multiple functions simultaneously: it catalyzes isomerization to improve cold flow properties, maintains high diesel fuel yield through selective reaction pathways, and can be integrated into existing hydroprocessing units. This multi-functionality reduces overall process complexity despite the advanced catalyst technology.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 efficiently converts unconventional feedstocks into diesel fuels with significantly lower cloud and pour points, improving cold flow properties while maintaining high yield, thus addressing the inefficiencies of conventional methods.

Implementation Method 1

a process for hydroisomerising a diesel feedstock... contacting a diesel feedstock with a hydroisomerisation catalyst... to provide a diesel fuel having a reduced cloud point and a reduced pour point

Methodology Applied

Scientific EffectHydroisomerisation: Catalysis

Data Source

PatentUS11987757B2Processes for producing diesel from unconventional feedstocks

Publication Date: 2024.05.21 CHEVRON USA INC

AI summary

Described herein are processes for hydroisomerising an unconventional feedstock using a hydroisomerisation catalyst comprising zeolite SSZ-91, zeolite SSZ-32, or zeolite SSZ-32x to provide a diesel fuel.