 |
|
Pre-ignition stage:
The droplet is heated and evaporation of the volatile material begins.
This stage ends with the self -ignition of the vapour surrounding the
droplet
|
|
|
Volatiles combustion stage:
The volatile constituents of the oil and the cracked products burn in an
enveloped flame surrounding the droplet. The stage ends by the flame dying
away as the evolution of flammable material ceases.
|
 |
|
Coke combustion stage:
When the flame dies hot gases including oxygen can reach the hot surface
of the coke residue. It glows red and burns at 1400 - 1700 K. The unburned
coke left after combustion is called a cenosphere.
|
|
|
|
BYCOSIN PRODUCTS WILL:
Improve
combustion efficiency, thus providing better fuel
economy due to
optimum combustion and improved heat transfer.
Reduce the soot number which allows a reduction of excess
air, resulting in both lower NOX and less SO3
in the combustion gases, and an increase
in plant efficiency.
Catalyse
and provide more complete combustion thus reducing the amount
of soot and coke in the flue gases.
Improve the atomization of the fuel. The smaller droplets
produced provide a better mixing with oxygen giving earlier completion of combustion.
Disperse asphaltenes which provides more complete
combustion.
Reduce soot and stack solids emissions.
Prevent soot and coke deposits.
|
|
|
|
Click to
expand
Photo taken in electron microscope of cenospheres. The use of Bycosin
with a catalyst has made the cenosphere to the right clearly more
completely combusted, porous and fragile.
|
|
BYCOSIN
PRODUCTS WILL:
Indirect
reduce the formation of SO3 and NOx
by a possibility to reduce excess air.
Prevent formation of vanadium deposits, which reduces the catalytic
oxidation of SO2 to SO3.
Provide better plant economy through lower environmental charges.
|
|
|
COMBUSTION AND RELATED EMISSIONS
1.
Incomplete
combustion
– Soot and stack solids emission
Soot
and coke cause problems in boilers, diesel engines and gas turbines
reducing both combustion and heat transfer efficiency, and causing environmental
pollution by stack solids and soot emissions.
Carbon monoxide, soot and coke particles are produced during incomplete
combustion. Soot, also called flame soot, is comprised of particles less
than 1 µm. Coke particles form during incomplete combustion of heavier
oils, after the lighter fractions in an oil droplet have evaporated and
burned. A carbon sphere remains which acts as a carrier for inorganic
materials such as vanadium, sodium and sulphur compounds, which form
deposits and cause fouling.
-
Insufficient
oil atomization. The efficiency of
atomization depends on the design of the fuel injector or burner tip,
on the nature of the fuel, whether it is homogeneous or not, the
fuel viscosity and its surface tension. A larger oil drop will not
burn completely, and will result in formation of soot and carbon
particles, which cannot be fully burned, but causes soot or coke
formation. The picture below shows the time it takes for oil drops of
different sizes to be burned. Click
for chart
-
Flame
length. A too long
flame that impinges on the combustion chamber or furnace wall will
generate more flame soot than a short flame. A flame that is too long
increases the exit temperature from the furnace leading to rapid
deposit build-up on the super heater tubes of a boiler. Likewise
increased exhaust gas temperature from a diesel engine combustion
chamber leads to exhaust valve failure and turbocharger deposits.
-
Asphaltene
agglomerations
impede efficient atomisation and burn unevenly.
-
Insufficient
supply of oxygen.
 |
|
Soot and stack solids emissions
without and with Bycosin. In this example the emission was reduced by
over 90%. |
A selection of some of our products:
BYCOSIN 3000
is a highly concentrated organo metallic additive for light and heavy
fuel oils. This neutral and oil-soluble product
gives a strong reduction of the stack solid
formation. The active components in BYCOSIN 3000 are an optimum blend
of surface-active organo metallic
combustion catalysts based on metals, which for instance
the authorities consider harmless from an environmental point of view.
BYCOSIN
6150
is a neutral, oil soluble, organo metallic additive especially developed
for cracked heavy fuel oils with high
asphaltene content. 6150 has a very heavy dispersing
and homogenizing effect on the asphaltene micelles in the heavy fuel
oil and this together with a special synergistic
flame catalyst combination will give reductions
of the oil coke and flame soot quantities in the size of 70-90%. The
active components in 6150 are an optimum
blend of surface-active organo-metallic combustion
catalysts based on metals, which for instance the authorities consider
harmless from an environmental point of view.
>Read
more about combustion
2. Emissions of SOx and NOx
Fuel
oil contains extremely varying amounts of sulphur which forms sulphur
dioxide during combustion. Part of the sulphur dioxide converts to sulphur
trioxide in the boiler superheater and in the diesel engine cylinder and
in both cases this causes severe corrosion and deposits. The production
of SO3 can be reduced in a boiler by decreasing the excess air.
NOx is formed mostly from the reaction between the nitrogen and
oxygen in the combustion air at high temperatures. The possibility to
reduce the excess air in a furnace leads to a reduction in the amount of
.
In
addition to SOx being damaging to both boiler plants and diesel
engines, the emission of SOx and NOx
creates environmental problems.
|
Top
|
The chart to the left shows stack solids and NOX
reduction in a power heating plant.
|
|
