Hydrotreating Catalyst for Diesel Cold Flow
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Solution Overview
Problem
Conventional methods for converting vegetable oils and fats into hydrocarbon compounds for diesel fuel face challenges such as poor oxidative stability, cold climate gelation, and undesirable properties like high pour and cloud points, which affect their suitability for use in diesel fuel, while also being costly.
Innovation Solution
A process involving the use of a catalyst comprising cobalt and molybdenum on a zeolite support under hydrotreating conditions to convert triglycerides, diglycerides, monoglycerides, and free fatty acids into C10-C30 hydrocarbons, improving cold flow properties and cetane rating of diesel fuel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional hydrotreating processes are used to convert vegetable oils and fats into hydrocarbons, then the conversion to diesel fuel boiling range compounds is achieved, but the products exhibit poor cold flow properties including high pour and cloud points
Solution Approach 1:
The patent changes the chemical parameters of the reaction by using a dual-catalyst system comprising a hydrotreating catalyst (such as CoMo or NiMo on alumina) and a dewaxing catalyst (such as ZSM-5 zeolite). This catalytic parameter change enables selective cracking of wax components while maintaining hydrotreating function, thereby lowering pour and cloud points to improve cold flow properties without sacrificing diesel fuel suitability
Solution Approach 2:
The patent employs a composite catalytic system combining two different catalyst types with complementary functions. The hydrotreating catalyst removes heteroatoms and saturates unsaturated bonds, while the dewaxing catalyst selectively cracks n-paraffins and iso-paraffins. This composite approach resolves the contradiction by achieving both adequate conversion and improved cold flow properties
2Ease of manufacture
If unmodified vegetable oils and fats are used as diesel fuel additives, then cost is reduced and lubricity is improved, but injector coking and combustion chamber degradation occur
Solution Approach 1:
The patent extracts and removes the problematic components from vegetable oils and fats through catalytic conversion. The process removes oxygen-containing functional groups, unsaturated bonds, and long-chain n-paraffins that cause coking and combustion chamber issues. By converting these materials into hydrocarbons with diesel fuel boiling range properties, the harmful factors are eliminated while retaining the cost and lubricity benefits
Solution Approach 2:
The patent converts the harmful properties of unmodified vegetable oils and fats into beneficial characteristics through catalytic transformation. The same materials that cause coking and degradation are converted into clean-burning hydrocarbons with appropriate molecular weights and saturation levels, turning a harmful feedstock into a beneficial fuel component
3Productivity
If harsh reaction conditions are used to convert vegetable oils into hydrocarbons, then conversion efficiency is improved, but the products exhibit undesirable properties such as high pour and cloud points
Solution Approach 1:
The patent segments the conversion process into two distinct catalytic functions: hydrotreating to remove heteroatoms and saturate bonds, and dewaxing to selectively crack wax components. This segmentation allows moderate reaction conditions to achieve both high conversion efficiency and low pour/cloud points, avoiding the need for harsh conditions that would compromise cold flow properties
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 cold flow properties and cetane rating of diesel fuel, reducing sulfur content and improving liquid yield, making the hydrocarbon products more suitable for diesel fuel applications compared to conventional methods.
Implementation Method 1
contacting the fatty materials with a catalyst comprising cobalt and molybdenum on a zeolite support under hydrotreating conditions
Implementation Method 2
The process occurs under conditions sufficient for converting at least a portion of the at least one fatty material into at least one member selected from the group consisting of C10-C30 hydrocarbons
Data Source
AI summary
Methods for producing C10-C30 hydrocarbons from fatty materials, such as triglyceride compounds, are provided. Hydrocarbon compounds, particularly those boiling in the temperature range of between about 80° F. to about 1000° F., are produced by contacting a fatty material with at least one catalyst comprising cobalt and molybdenum on a zeolite support under hydrotreating conditions. Additional hydrotreating catalysts may also be used to further improve the properties of the hydrocarbon product.