Environmental Engineering Reference
In-Depth Information
Chapter 4
Mechanisms of Nanoparticle Formation
and Reformation in the Atmosphere
Nicolae Strambeanu, Laurentiu Demetrovici, and Dan Dragos
Abstract Several relevant models of nanoparticle formation and reformation in the
atmosphere are underlined: the mechanism of forming fine ash particles in coal-
fired thermal power plants; carbon particulates formed either directly or through
partial oxidation intermediates; acid rain, bases, ammonia, saline or oxide partic-
ulates formation mechanism. For solid or liquid particulate matter of organic nature
present in the atmosphere, the phases of the partial oxidation of organic compounds
and the dioxin and furan generation in various combustion systems are presented.
The mechanism of reforming these compounds from flue gas through de novo
syntheses initiated through the conversion of carbon dioxide into formose is also
described.
4.1
Introduction
Nanoparticles are entities that move freely until they combine with particles of
similar nature or react with particles of different chemical nature. Such processes
increase their specific mass up to a value that allows their sedimentation.
Figure
4.1
shows a physico-chemical method of forming fine ash particles in
fluidised bed coal-fired thermal power plants [
1
].
It must be specified that in all combustion chambers, irrespective of the fuel
used, carbon particulates can form directly, through the incomplete combustion of
the organic substrate:
