Plasma-Ionized Flue Gas Mixing for Biomass PM2.5 Agglomeration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current biomass boiler particulate emission control technologies, such as Electrostatic Precipitation and Fabric Filter Systems, are costly, difficult to retrofit, and ineffective in reducing fine particulate matter (PM2.5) emissions, which pose significant health hazards due to their small size and high emission rates during start-up and shut-down cycles.

Innovation Solution

A method involving a plasma source to ionize a gas stream, which is then directed towards exhaust gases containing particulates, causing agglomeration of fine particulates into larger ones, making them easier to collect, using a non-thermal plasma source like a dielectric barrier discharge reactor, and coupling this system to the exhaust flue of combustion devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If current particulate emission control technologies (ESP, cyclones, fabric filters) are used, then particulate emissions can be reduced, but the cost is high and maintenance requirements are high

Engineering Contradiction:

Improveparticulate emissionsVSAvoidsystem complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The invention changes the physical state of the gas stream by ionizing it through plasma generation. This parameter change (from neutral to ionized) enables new mechanisms for particulate removal that are simpler and more cost-effective than traditional methods. The ionized gas stream interacts with particulates to form agglomerates that can be more easily separated.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces complex mechanical filtration systems (fabric filters, electrostatic precipitators) with a plasma-based system that uses electromagnetic fields to ionize the gas stream. This substitution eliminates the need for complex mechanical components while achieving effective particulate control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-generated harmful factors

If fabric filter systems and electrostatic precipitators are used, then particulate emissions can be controlled, but retrofitting is difficult

Engineering Contradiction:

Improveparticulate emissionsVSAvoidretrofit difficulty

Core Design Contradiction:

Object-generated harmful factorsVSEase of manufacture

Solution Approach 1:

The invention segments the exhaust gas flow by introducing a plasma-generated ionized gas stream that mixes with the particulate-containing exhaust. This segmentation allows the plasma treatment to be applied locally within the exhaust stream without requiring complete system replacement or complex integration of traditional filtration systems.

Inventive Principle:

Principle #1Segmentation

3Quantity of substance

If smaller biomass boilers are used, then fuel consumption is reduced, but particulate emission rates are significantly higher during start-up and shut-down

Engineering Contradiction:

Improvefuel consumptionVSAvoidparticulate emission rates

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The invention applies plasma ionization to the exhaust gas stream during all operational phases, including start-up and shut-down. This preliminary treatment of the exhaust stream prevents the formation of harmful fine particulates during transient operations, addressing the emission problem before it occurs rather than treating it afterward.

Inventive Principle:

Principle #10Preliminary action

4Productivity

If fine particulate matter (PM2.5) is emitted, then combustion efficiency is maintained, but health hazards increase due to small particle size

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidhealth hazards

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention introduces ionized gas species as intermediaries that facilitate the agglomeration of fine particulates. These ionized intermediaries transfer charge to the particulates, causing them to attract and merge into larger particles. This process maintains combustion efficiency while eliminating the health hazards associated with fine particulate emissions.

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 method significantly reduces the proportion of fine particulates (PM2.5) by increasing the size of particulates greater than 2.5 microns, making them more collectable, and can reduce PM2.5 emissions by up to 75% while being cost-effective and easily retrofittable to existing equipment.

Implementation Method 1

directing a stream of gas towards a plasma source to generate an ionised gas stream

Methodology Applied

Scientific EffectPlasma ionization: Ionisation

Implementation Method 2

directing the ionised gas stream towards a gas comprising particulates to convert a portion of the particulates into agglomerated particulates

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentUS12134066B2Combustion apparatus and method of making a combustion apparatus

Publication Date: 2024.11.05 THE UNIVERSITY OF NEWCASTLE

AI summary

This invention relates to a method of increasing the size of particulates in a gas comprising particulates, e.g. a gas that is formed from the combustion of fuels. The method comprises mixing an ionised gas stream with the gas comprising particulates.