Fuel Additive for Injector Deposit Removal
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Solution Overview
Problem
Diesel fuel injectors operating on ultra low sulfur diesel fuels are prone to internal deposits due to interactions between corrosion inhibitors, biofuel components, and alkali metal salts, leading to performance issues, power loss, and increased maintenance costs, as conventional detergents are either ineffective or detrimental at high treat rates.
Innovation Solution
A fuel additive composition containing hydrocarbyl-substituted dicarboxylic acid compounds with specific acid numbers and alkyl or alkenyl groups is used, which effectively reduces internal deposits and improves injector performance by operating diesel engines with a sulfur content of 50 ppm or less and 0.1 to 2 ppm alkali metal as a salt, without adversely affecting engine components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional detergents (succinimide, Mannich, quaternary ammonium salts) are used to remove internal deposits, then deposit removal effectiveness is improved, but treat rates must be excessively high which becomes detrimental to engine components
Solution Approach 1:
The patent changes the chemical parameters of the detergent by using alkyl- and alkenyl-substituted dicarboxylic acids with specific chain lengths (C12-C24) and controlled total acid numbers (20-200 mg KOH/g). This parameter optimization allows effective deposit removal at treat rates of 1-100 ppm, avoiding the excessively high treat rates required by conventional detergents that harm engine components.
Solution Approach 2:
The invention employs composite detergent formulations combining dicarboxylic acid components with specific physical and chemical properties (molecular weight 200-2000, controlled acid number, specific carbon chain lengths). This composite approach creates a detergent that is both highly effective at removing alkali metal salt deposits and safe for engine components at low treat rates.
2Productivity
If high pressure fuel injection systems (up to 2000 bar) are implemented to meet emissions requirements, then emissions performance is improved, but injectors become more sensitive to fuel particulate contamination
Solution Approach 1:
The patent applies preliminary action by using the dicarboxylic acid detergent to prevent and remove deposits before they can accumulate to problematic levels in the tight-tolerance high-pressure injector components. The detergent continuously cleans internal surfaces, preventing the buildup of alkali metal salt deposits that would otherwise interfere with the precise metering required at 2000 bar injection pressures.
3Manufacturing precision
If tight tolerances are used in injector design (hole diameter <160 μm, clearance <10 μm) for precise fuel metering, then fuel metering precision is improved, but injectors become more sensitive to deposits leading to stuck injectors
Solution Approach 1:
The patent implements self-service by incorporating the dicarboxylic acid detergent directly into the fuel supply, allowing the fuel system to continuously clean itself. The detergent travels with the fuel through the tight-tolerance injector components, automatically removing deposits as they form and preventing stuck injectors without requiring external maintenance or disassembly of the precision components.
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 additive significantly reduces internal deposits, restores lost engine power, and is more effective at lower treat rates compared to conventional detergents, demonstrating improved power recovery and injector cleanliness in diesel engines.
Implementation Method 1
The internal deposits are believed to be a result of certain common corrosion inhibitors, biofuel components and acidic friction modifiers, or other carboxylic components used in the fuel interacting with trace amounts of alkali metal salts that form salts that are relatively insoluble in ultra low sulfur diesel (ULSD) fuels
Data Source
AI summary
Methods for improving the injector performance, unsticking fuel injectors, and reducing an amount of alkali metal carboxylate deposits on internal components of fuel injectors. The method includes operating the diesel engine on a fuel composition comprising a major amount of diesel fuel and from about 45 to about 550 ppm by weight based on a total weight of fuel composition of a fuel additive consisting essentially of a compound of the formulawherein R is an alkyl or alkenyl group containing from 20 to 170 carbon atoms. The additive has a total acid number (TAN) ranging from about 50 to about 290 mg KOH/g. Fuel injectors of the fuel injected diesel engine have an average injector hole diameter of less than 160 μm and an average smallest clearance between injector needle and injector barrel/casing of less than about 10 μm.