Mannich Base Detergent Ratio for LSPI Reduction

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Solution Overview

Problem

Low-speed pre-ignition (LSPI) in spark-ignition internal combustion engines, particularly in modern turbocharged engines with high calcium content engine oils, leads to efficiency and performance issues, including potential engine damage and restricted torque at low speeds, which current solutions like reformulating engine oils with low calcium content do not adequately address.

Innovation Solution

The use of an unleaded gasoline fuel composition containing a detergent additive package with a Mannich base detergent mixture, comprising a first Mannich base detergent derived from a di- or polyamine and a second Mannich base detergent derived from a monoamine, in a specific weight ratio, along with an antiwear component and a polyether carrier fluid, to reduce LSPI occurrences even in engines lubricated with high calcium content oils.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high calcium content engine oil is used, then engine lubrication performance is improved, but Low Speed Pre-Ignition (LSPI) occurrence increases

Engineering Contradiction:
Improveengine lubrication performanceVSAvoidLSPI occurrence
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A detergent additive package acts as an intermediary substance in the fuel composition that counteracts the harmful effects of calcium deposits. The detergent additives clean and prevent deposit formation on piston crevices and injectors, thereby mitigating LSPI events while allowing high calcium content engine oil to maintain its lubrication benefits

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical composition parameters of the fuel by incorporating specific detergent additives (such as succinimide detergents, Mannich base detergents, and alkylphenolic detergents) in optimized concentrations. This parameter change in fuel chemistry enables the system to tolerate high calcium oil content without suffering from increased LSPI

Inventive Principle:
Principle #35Parameter changes

2Reliability

If engine management systems are calibrated to avoid high torque low speed operating regimes, then LSPI is prevented, but fuel economy and drivability are compromised

Engineering Contradiction:
ImproveLSPI preventionVSAvoidfuel economy
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The detergent additives perform preliminary cleaning and protective actions on engine surfaces before LSPI events can occur. By pre-preventing deposit formation on piston crevices and injectors during normal operation, the system enables safe operation in high torque low speed regimes without requiring restrictive calibration

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If conventional detergent additives are used, then deposit control is maintained, but LSPI reduction is insufficient in high calcium oil environments

Engineering Contradiction:
Improvedeposit controlVSAvoidLSPI reduction
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The invention creates a composite detergent additive package combining multiple types of detergents (succinimide detergents, Mannich base detergents, alkylphenolic detergents) with specific synergistic interactions. This composite formulation provides enhanced LSPI protection in high calcium oil environments compared to conventional single-type detergent additives

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3697873B1Method for reducing low speed pre-ignition
Publication Date: 2021.05.26 SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV

AI summary

Use of an unleaded gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises a gasoline base fuel and detergent additive package, wherein the detergent additive package comprises a Mannich base detergent mixture, wherein the mixture comprises a first Mannich base detergent component derived from a di- or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the spark- ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200ppmw to 3000ppmw of calcium, based on the total lubricant composition.