Pretreated Gasoline Particulate Filters for Rapid Cake Filtration

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Solution Overview

Problem

Newly installed gasoline particulate filters (GPFs) in gasoline direct injection engines have low initial filtration efficiency, making it difficult to meet certification testing requirements for particulate emissions, as they need time to establish cake filtration, which is slow due to the limited operating time available for vehicle conditioning before testing.

Innovation Solution

The solution involves pretreating the GPFs by partially filling their pores with a particulate substance, such as soot or ash surrogates, before installation, or using fuel additives that produce combustion products to rapidly achieve cake filtration, thereby enhancing initial filtration efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filter is designed with larger size, increased porosity, or modified pore size distribution to improve initial filtration efficiency, then initial filtration efficiency is improved, but device complexity, packaging constraints, and exhaust stream distribution challenges increase

Engineering Contradiction:

Improveinitial filtration efficiencyVSAvoidfilter design complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The filter substrate is pretreated with a dopant composition before the filter is installed in the vehicle. This preliminary action creates a primed surface that promotes rapid cake filtration formation during initial vehicle operation, eliminating the need for design modifications to improve initial efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The inventors change the chemical parameters of the filter substrate by impregnating it with a dopant composition containing specific compounds (e.g., manganese salts, organic additives) at controlled concentrations. This chemical modification enables rapid cake formation without changing the physical structure or size of the filter

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the filter is designed to compensate for poor initial efficiency, then initial filtration efficiency is improved, but cost increases

Engineering Contradiction:

Improveinitial filtration efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The filter substrate is pretreated with a dopant composition during manufacturing before installation. This preliminary doping enables the filter to achieve high initial efficiency through rapid cake formation, eliminating the need for expensive design modifications

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dopant composition uses relatively inexpensive chemical compounds (metal salts, organic additives) that are applied in small amounts to the filter substrate, providing a low-cost solution compared to redesigning the entire filter structure

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If normal vehicle operation is used to accumulate particles for cake filtration, then cake filtration is eventually achieved, but the time required exceeds the certification testing window

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidconditioning time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The filter substrate is pretreated with a dopant composition that creates a primed surface promoting rapid particle accumulation. This preliminary action reduces the conditioning time from hundreds/thousands of kilometers to a fraction of that distance, enabling certification testing to be completed within the available time window

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dopant composition acts as an intermediary substance that facilitates rapid cake filtration formation. It mediates between the exhaust particles and the filter substrate, accelerating the cake formation process without requiring extended vehicle operation

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This approach allows for rapid achievement of high filtration efficiency, exceeding 80% after 100 initial miles, enabling compliance with emission standards and optimizing filter design for lifetime performance.

Implementation Method 1

The low filtration efficiency for a fresh or low-mileage GPF results from the need to establish cake filtration in the GPF as particulate matter removed from the exhaust stream builds up on the filter substrate

Methodology Applied

Scientific EffectCake filtration: Deposition (physical)

Implementation Method 2

contacting the gasoline particulate filter with an exhaust stream comprising particulate matter derived from a priming composition

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS11441458B2Gasoline particulate filters with high initial filtering efficiency and methods of making same

Publication Date: 2022.09.13 AFTON CHEMICAL CORPORATION

AI summary

Gasoline Direct Injection (GDI) engines require gasoline particulate filters (GPFs) as a key component of the emissions control system to reduce particulate emissions. GPFs are known to have poor initial performance, with performance increasing after the filter develops a cake. This poor initial performance make it impossible to accurately assess vehicle emissions performance at the mileage requirements for vehicle certification. Compositions and methods are disclosed to improve filtration efficiency in a fresh or low mileage GPF.