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Hot gas cleaning using advanced ceramic Filter technology for municipal waste incinerators

Objective


* Survey of MSW dust and gas compositions.
* Development and testing of a model dust to simulate MSW fume/dust.
* Mathematical model of the filtering and cleaning process.
* Methods of producing dispersed nano-particle barrier coatings and porous membranes.
* Use of lime and calcium sulphate for particle conditioning of flue gases.
* New technique and apparatus for the quantification of filter cake adhesion forces.
* Microwave assisted gas firing method achieving sintering in much shorter times.
* Tests on single and multiple full scale candles at 650oC.
* Validated 3D Model of gas flows in filter rig.
* Technical economic assessment showing viability of process.
Objectives and content
Incineration processes are accepted methods by which
energy is recovered into the European community from
sources such as Municipal Solid Waste (MSW). The
products of combustion, however, represent a range of
potentially environmentally harmful by-products, which
need to be separated or rendered inert at reasonable
financial cost.
Off gases in conventional MSW incinerators, must be
cooled to below 300-200 C before passing through the
electrostatic precipitator (ESP) or bag filter to remove
particulate. This is costly in terms of capital and
space. Furthermore, harmful acidic gases present also
require elaborate downstream washing or adsorption
systems, requiring plants made of costly corrosion-resistant materials to withstand the waste liquors.
In addition, fly ash present in the post combustion zone
of MSW incinerators greatly enhances the production of
polychlorinated dibenzo-dioxins or polychlorinated
dibenzo-furans (PCDD/Fs or "dioxins"), by providing
catalytic metal rich surfaces for heterogeneous
reactions, nucleation and condensation processes as these
combustion gases cool down from about 450 C to 250 t C
(de novo synthesis). By the year 2000, average European
incinerator operating costs are expected to increase by
60% as a result of the necessary increased expenditure on
pollution control.
Hot gas filtration methods offer an erudite solution to
de novo synthesis of dioxins by removing the fly ash
particles from the critical temperature regime, and also
offer a beneficial catalytic conversion of harmful
inorganic gases to less harmful species. However, to
operate at the temperatures required to be effective,
around 800 C, technical solutions to filter clogging or
are needed, such that the ceramic filters can be cleaned
using convenient methods similar to pulse jet techniques.
This project aims to provide these solutions.
A multi-disciplinary approach will involve collaborating
scientists and engineers from four Member States.
Specialists in the sintering and firing of ceramics
will strive to improve the surface strength and impart a
highly microporous barrier layer on filter surfaces.
Materials specialists will measure filter cake cohesive
forces.
Experts in hot gas filtration and cleaning processes
will assess particle conditioning and coatings on filter
efficiency and cleaning performance.
Computational fluid dynamics specialists will model gas
flows through and around porous media during the cleaning
process.
In this way, successful European methods of high
temperature filtration processes involving ceramic filter
media will become Best Available Techniques Not Entailing
Excessive Cost (BATNEEC), in treating the hot gases from
MSW incineration and related processes. Present
developments in hot gas filtration have been dominated by
the USA, where $20 million pilot hot filter plants for
pressurised fluidised bed combustion systems have been
built.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

CAPENHURST.TECH LIMITED
Address
Capenhurst Technology Park
CH1 6ES Chester
United Kingdom

Participants (4)

AUSTRIAN RESEARCH CENTERS SIEBERDORF
Austria
Address

2444 Seibersdorf
ENGINEERING SOLUTIONS INTERNATIONAL LTD
Ireland
Address
Howth Junktion Business Park
1 Dublin
FORSCHUNGSZENTRUM KARLSRUHE GMBH - TECHNIK UND UMWELT
Germany
Address
5,Hermann-von-helmholtz-platz 1
76344 Eggenstein-leopoldshafen
Universität Gesamthochschule Essen
Germany
Address
Leimkugelstraße 10
45141 Essen