Diesel Fuel Blowing Agents for Ignition Delay and Cetane Number
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Solution Overview
Problem
Current diesel fuel ignition improvers, such as 2-ethylhexyl nitrate, compromise thermal stability and are difficult to store, while alternatives like AZDP and DHCDD have limitations in effectiveness and stability, necessitating a more efficient cetane number enhancer and ignition delay reducer.
Innovation Solution
Incorporating blowing agents like ester compounds, oxalate compounds, and diazene compounds with specific solubility and decomposition temperature ranges into diesel fuels to enhance evaporation rates and cetane numbers, thereby improving combustion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If 2-ethylhexyl nitrate (2-EHN) is used as an ignition improver, then ignition delay is reduced and cetane number is improved, but thermal stability deteriorates and storage safety worsens
Solution Approach 1:
The patent changes the chemical parameters of the ignition improver from 2-EHN to compounds with specific decomposition temperature ranges (50-300°C). This parameter change maintains the ignition delay reduction function while improving thermal stability by selecting compounds that decompose at higher temperatures than 2-EHN (which decomposes at about 43°C).
Solution Approach 2:
The patent employs blowing agents that are designed to decompose completely during the combustion process, leaving no harmful residues. These agents serve their purpose (reducing ignition delay) and then are consumed, avoiding the thermal stability issues associated with 2-EHN accumulation and decomposition at low temperatures.
2Quantity of substance
If 2-ethylhexyl nitrate (2-EHN) is used as an ignition improver, then cetane number is improved, but storage difficulty increases due to decomposition and explosive mixture formation
Solution Approach 1:
The patent changes the stability parameters of the ignition improver by selecting compounds with decomposition temperatures between 50-300°C. This parameter change ensures the compound remains stable during storage at ambient temperatures while still providing effective cetane number improvement and ignition delay reduction when needed.
3Loss of time
If AZDP (azodicarboyl dipiperidine) is used as a cetane number improver, then ignition delay is reduced, but evaporation rate improvement is insufficient compared to required combustion properties
Solution Approach 1:
The patent uses composite blowing agent formulations comprising multiple components (esters, oxalates, and/or diazenes) that work synergistically. This composite approach provides both the ignition delay reduction function and the enhanced evaporation rate improvement needed for optimal combustion efficiency, overcoming the limitations of single compounds like AZDP.
Solution Approach 2:
The patent changes the physical parameters of the fuel composition by introducing blowing agents with specific volatility characteristics. These agents increase the evaporation rate of the diesel fuel, which complements the ignition delay reduction effect and improves overall combustion efficiency beyond what AZDP alone can achieve.
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 use of these blowing agents increases the evaporation rate and cetane number of diesel fuels, outperforming traditional additives like AZDP, while maintaining thermal stability and safety, making them suitable for modern engines.
Implementation Method 1
the fuel additives disclosed herein (referred to herein as 'blowing agents') increase the evaporation rate of a diesel fuel to which the fuel additive is added
Implementation Method 2
the blowing agent has a solubility in diesel base fuel at 25° C. of 100 mg/kg or greater, a decomposition temperature in the range from 50° C. to 300° C. as measured by thermogravimetric analysis (TGA)
Data Source
AI summary
Diesel fuel composition comprising a diesel base fuel and at least one blowing agent wherein the blowing agent is selected from ester compounds, oxalate compounds and diazene compounds and wherein the blowing agent has a solubility in diesel base fuel at 25° C. of 100 mg/kg or greater, a decomposition temperature in the range from 50° C. to 300° C. as measured by thermogravimetric analysis (TGA), and wherein the diesel fuel composition has an evaporation rate of greater than that of the diesel base fuel as measured by acoustic levitation.