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NEW INSIGHTS IN THE BURNING AND COMBUSTION OF HEAVY –NON VOLATILE ORGANIC LIQUIDS

Thermolysis of non-volatile organic liquids  > 150 Cel.

 

 

Thermolyzing apolar organic liquids acquire electrolytic properties:

electronegativity and electrolytic conductivity

 

 

                                                                                    

Colloidal and electrochemical aspects of the generation of soot and coke

 

 

Electrodynamics:

 

electrochemical active species

charge all interfaces,

surface charges cause electrostriction and force carbon agglomerates apart.

 

                    ▼

The combustion of aerosols carrying large droplets tends to soot

 

 

Pre-ignition

 

Volatiles combust

The origin of soot (Bycosin)

 

Stability laws suggest that the rate of agglomeration depends

on interaction forces.

The kinetic of agglomeration depends on electrical fieldstrength effects.

 

 

Mobile carbon atoms are prone to cluster. Such clusters grow by absorption of mobile carbon atoms and sterically fitting ions and molecules. When particles accomplish electrical conductivity, surface charge develops by charge transfer.

 

Similarly charged carbon particles repel each other, when dissimilarly charged attraction results. Brownian motion causes charge transfers of electrons that promote structural densification. The growth of soot and coke is controlled by hydrodynamic and dielectric properties.

 

 

ICC2008

Characteristics of soot

 

amount and particle size least at

 

maximum electronegativity and

minimum (electron) conductivity

&

Soot is at all times contacted

  by dissolved polyquinones

 

Characteristics of coke

 

deposition rate least at

 

maximum electronegativity and

minimum (electron) conductivity

&

Coke is at all times contacted

   by dissolved polyquinones

COLLODIAL and ELECTROCHEMICAL ASPECTS

COLLOIDAL AND ELECTROCHEMICAL ASPECTS

OF THE GENERATION OF SOOT AND COKE

 

J.J.C. Oomen

 

The question why bitumen and varieties of ‘heavy’ oil do not atomize into aerosols in the same manner as paraffins do at the wick of a candle has been analyzed, see Oral “Electrolytic effects generated by thermolysis of non-volatile organic liquids”. It showed that during thermolysis colloidal and electrochemical interactions occur. Experiments indicate that electrolytic parameters like electronegativity and electrical conductivity control a number of colloidal and physicochemical processes.

Thermolytic generated mobile carbon atoms are prone to cluster. Such clusters grow by absorption of mobile carbon atoms and sterically fitting ions and molecules. When agglomerates accomplish electrical conductivity, surface charge develops by charge transfer. Similarly charged carbon particles repel each other, but when dissimilarly charged attraction results. Brownian motion causes charge transfers of electrons that promote structural densification. The growth of soot and coke is controlled by hydrodynamic and dielectric properties.

At interfaces between coexisting liquid phases and at surfaces of submerged particles electronegativities and electrical conductivities diverge. This divergence cause electrokinetic effects. The solid/liquid and the solid/gas surfaces of partially submerged carbon particles, e.g. at the outside of wicks, are acted upon by traces gaseous oxygen and by the electrolytic condition of the liquid. These dualities induce charge transports, causing every kind of interface to become charged electrically.

During thermolysis electrical interactions control physicochemical mechanics, like atomization of non volatile liquid organics at heated substrates and growth of carbon particles inside thermolyzing droplets. When partially submerged particles are exposed to a trace of gaseous oxygen the agglomeration of carbon clusters inside droplets accelerates. The electrolytic condition of the liquid controls agglomeration as well. Substantial increases of the local conductivity induces surfaces to discharge, weakens electrostatic repulsion between carbon particles and accelerates agglomeration.

Thermolytic reactions proceed according to quite different time scales. The release of electrochemically active species, like hydrogen and hydrogen activated compounds lower the electronegativity in seconds or less, whereas the conductivity increases in minutes. The difference between these time scales can be understood as being due to their primary and secondary natures. The disintegration of molecules releases components that instantly boost charge transfer processes at interfaces, where the concentration of mobile carriers of electrical charge develops more slowly as a result of reactions between fragments of molecules.

Electrolytic factors, that contribute to atomization of non-volatile fuel and the generation of soot, seem also be in control of the generation of carbon agglomerates, that grow on walls inside “cokers” and more generally on walls inside reaction vessels where organic processes proceed. Electronic sensors that locally record on line electronegativity and conductivity simultaneously are of value to optimize process engineering.

The electrochemical conditions of charge transfer during the growth of soot and the deposition of coke indicate that when cooled down both substances are wetted and remain at all times contacted by dissolved polyquinones. These substances are well known for their reactivity. The molecular structure of polyquinones produced during thermolysis and agglomeration of carbon clusters will reflect the molecular structure of thermolyzing originals. Such relations are of value to document health hazards of soot.