OMNIATEX IMPIANTI CHIMICI Srl has always been
working, since more than 30 years, in the field of Engineering, Manufacturing,
Erection, Start-up and Commissioning of advanced technology chemical plants,
mainly specialized in environmental air pollution control systems and solvent
recovery plants. The production mainly involves adsorption, absorption,
distillation and filtration plants.
Final destination of the plants manufactured by
OMNIATEX are mechanical shops, synthetic leather production, rotogravure printing
of magazines, food production, printing of flexible packaging for foodstuffs,
production of special papers, rubber belts and conveyors, adhesives films and
tapes, waste eater treatment plants, automotive parts and distilleries for
drinking spirit.
The very long experience in the field, has permitted
OMNIATEX to develop special plants dedicated to the adsorption of bad smelling
emissions, exhausted into the atmosphere by several production processes.
Several industrial process are exhausting bad smelling
emission that, with time, are becoming a noxious problem for the environment
around the production site. The bad smell is mostly due by organic molecules of
several different types, most common is those of the hydrocarbons, and by some
byproducts developed by their oxidation, by sulfur derived molecules, like
mercaptans or nitrogen derived molecules like ammines.
MOST appliED fields
FOR odors abatement Animal
and vegetal fats recovery Humus
production Baking of
fats and foods Industrial
breeding Chemical
plants Malls air
purification Coffee
roasting Natural gas odorizing Commercial
and industrial kitchens Paper and
cellulose industry Cosmetics
production Pharmaceutics Distilleries
and beverages production Slaughterhouses Fertilizer
production Soaps and
cleaners production Fish
flour production Sugar and
oils refineries Food
industry Urea/Formaldehyde
production Foundries Waste
water treatment plants
Putrescine Ammoniac Amine Fat mists Ammonia Fats mists Indole Formaldehyde Mercaptans Hydrogen sulfide Ammonia Triéthylamine Mercaptans Ammonia-Formaldehyde Hydrogen sulfide Methylmercaptan Triéthylamine Phenol Ammonia Caprylic Acid Nicotine AmmineSECTEURS PRODUCTIFS ET LEUR REJETS Rotten meat Production of foundry cores Triéthylamine Fats combustion Acroléin Fish meal production Foods baking Production of synthesis pharmaceuticals Ethylmercaptane Excrements Syrup fruits production Sulfur dioxide Mud and sludge drying Breathing Butyric aldheyde urea/formaldehyde resins drying Formaldéhyde Moquettes spreading Sewer Glass bottles sterilization Sulfur dioxide Light alloys foundries Sweat, animal smelling Tobacco smoke Biological treatments Natural gas odorization Mercaptans Vegetables (onions, garlic) Ethylmercaptane
seuil de perception des differentes SUBSTANCES | |||||
Component | ppmw | ppmv | Component | ppmw | ppmv |
Acétaldéhyde | 0,21 | Hydrogen sulfide | 0,18 | 0,12 | |
Amyl acetate | 1 | 0,19 | Indole | 0,001 | |
Acétone | 240 | 100 | Iodoform | 0,0017 | |
Acetic acid | 2,5 | 1 | Isoamylmercaptan | 0,00043 | |
Butyric acid | 0,00006 | 0,001 | Méthanol | 260 | 100 |
Valeric acid | 0,0062 | Méhylamine | 0,025 | 0,021 | |
Ethyl Acryl ate | 0,002 | 0,00047 | Métyléthycetone | 29,5 | 10 |
Acrylonitrile | 48 | 21,4 | Méthylisobuthylcetone | 1,9 | 0,47 |
Acroléin | 0,53 | 0,21 | Methylmercaptan | 0,0022 | 0,0011 |
Ammonia | 33 | 46,8 | Méthylmetacrylate | 0,86 | 0,21 |
Sulfur dioxide | 4 | 1,6 | Mono chlorobenzène | 0,21 | |
Benzene | 4,68 | Monomethylammine | 0,025 | 0,021 | |
Bioxyde di souffre | 0,47 | Artificial musk | 0,000005 | ||
Bromine | 0,3 | 0,047 | Nitrobenzène | 0,0023 | 0,0047 |
Chloral | 0,047 | Ozone | 0,05 | 0,025 | |
Chlorine | 1 | 0,314 | Para créosol | 0,001 | |
Chlorocetophenone | 0,016 | 0,0027 | Para xylene | 2 | 0,47 |
Ally chloride | 1,5 | 0,47 | Tetrachloroéthylène | 31,35 | 4,68 |
Benzyl chloride | 0,24 | 0,047 | Pyridine | 0,06 | 0,021 |
Methyl chloride | 22,2 | 11 | Methyl salicylate | 0,065 | |
Methylene chloride | 100 | Skatole | 0,0012 | ||
Créosol | 0,056 | 0,012 | Benzyl sulfide | 0,006 | 0,0021 |
Crotonaldéhyde | 0,062 | Carbon sulfide | 0,77 | 0,21 | |
Sulfur dichloride | 0,001 | Hydrogen sulfide | 0,00047 | ||
Diphényléter | 0,0012 | 0,1 | Biphenyl sulfide | 0,0047 | |
Diméthylacétamine | 46,8 | Bimethyl sulfide | 0,001 | ||
Diméthylformamide | 300 | 100 | Styrène | 0,19 | 0,047 |
Ethanol | 10 | Carbon tetrachloride | 71,8 | ||
Ethylmercaptane | 0,0002 | 0,0001 | Carbon tetrachloride (CH4) | 100 | |
Phénol | 0,28 | 0,047 | Carbon tetrachloride (CS2) | 21,4 | |
Formaldéhyde | 1,5 | 1 | Toluene | 8 | 2,14 |
Phosphine | 0,028 | 0,021 | Toluene diisocianate | 2,14 | |
Phosgène | 5,6 | 1 | Tricloroetilene | 114,5 | 21,4 |
Gaz HCl | 14 | 10 | Trim ethylamine | 0,00021 | |
Vanillin | 0,00008 |
The main theoretical concept that is the basis for
the abatement process is the Absorption and the Adsorption.
The adsorption Process by activated carbon is a
simple method, but with high retentivity efficiency for the neutralization of
bad smelling agents contained in a gaseous flow.
The adsorber medium is activated carbon, derived from
vegetal raw material, thermically treated to obtain a porous material with a
very large activated surface. The vegetal carbon is the best adsorption medium,
higher than a mineral one, and different impregnation processes raise the
abatement efficiency for special smells.
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The quality of an activated carbon is
based upon its activated surface, which is measured in B.E.T. (acronym of the
names of the three scientists who have realized this analysis method),
expressed in square meters of
active surface per gram of carbon. |
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Usually for air pollution treatment is used an high
activity carbon with more than 1100 m2/g of B.E.T. and OMNIATEX uses
a very good carbon, with at least
The adsorption is a mass transfer Process, as the air
flow components pass from the air stream into the carbon pores. The polluting
components molecules are attracted by the activated surface of the carbon by
forces called Van der Waals, from the name of the scientist who has studied
this physic phenomenon.
The progressive formation of multiple layers of
liquid components in the inner part of the pores reduces gradually the strength
of the Van der Waals forces up to the point in which equilibrium is reached and
no more components are captured by the pores.
The retention efficiency of the carbon, besides the activated surface, is given by:
v Pollutant's chemical and physical features |
v Activated carbon’s owns chemical and physical features |
v Distribution and size of the pores in the carbon |
v The air stream velocity through the carbon |
v The carbon bed depth |
v The relative humidity of the air stream |
v The temperature of the air stream |
v The pollutant concentration in the air stream |
v The pressure of the adsorption Process |
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The adsorption capacity of the carbon at the
equilibrium and to a given temperature and pressure, is plotted in a diagram
called ISOTHERM on which for each solvent concentration (or partial pressure)
is indicated the adsorption capacity expressed as percentage of solvent
retained by the carbon. The adsorption Process proceeds through
several steps before the equilibrium is reached. At the beginning the
pollutant odor is completely retained by the carbon and the air stream that
leaves the carbon bed is completely odor free. Progressively the polluting
components fill the pores of the carbon reducing the action of the Van der
Walls forces and the polluting mass transfers along the carbon bed until the
moment in which some odor appears in the air stream after the carbon bed.
This step is called BREAKTHROUGH. When breakthrough is reached the carbon bed of the
plant must be regenerated or changed to put again the plant in the optimized
adsorbing condition of the beginning, to continue to abate the odors. |
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If
the carbon bed can be regenerated “in situ” (on site) the efficiency of the
regeneration is mainly affected by:
v Polluting agent chemical and physical features
v Activated carbon chemical and physical features
v Length of the regeneration process
v Mechanical force made by the regenerating medium inside the pores
of the carbon
Main
applications fields of the abatement and deodorization plants are:
v Treatment of air flow coming from covered waste water treatment pools
v Treatment of air coming from town gas odorizer filling rooms
v Treatment of air flow will weak solvent concentration
v Treatment of bad smelling air flows
v Treatment of baking and curing ovens vents
The
manufacturing configuration of the plant follows the final destination and
service of the plant itself. This means that the plant could have filtering
panels, filtering cartridges or adsorbing vessels.
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Usually in
the first two cases, the carbon cannot be regenerated and must be emptied,
when filled with the polluting agents, and disposed off, filling again the
component with virgin carbon. This operation is manually or automatically
operated, depending from the plant size. When large
adsorbing vessel are employed, typical technology used for the treatment of
air flows coming from waste water pools or odorizer filling rooms, the
activated carbon is regenerated on the plant premises, with a special unit,
and can be reused for a very large number of odor abating cycles before its
substitution is needed. |
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The proved experience has allowed the development also
of special plants for the abatement of organics and inorganics exhausted into
the atmosphere by several production processes. The produces plants are based mainly on the absorption
process and OMNIATEX is an European Leader in hydrocarbons abatement with
many plants operating in the DMF, Ethanol and Methanol abatement. For the
abatement of bas smelling inorganics, plants are in operation for the
abatement of Acetic Acid, Ammonia, Hydrochloric Acid and Sulfur Dioxide. Different
technologies allows to use, as abatement medium, oils, water and water
solutions to face and to solve the various problem given by the different
productions. The
abatement plants efficiency is very high for several composants, allowing,
the most of the time, also the recovery and sometime the re-use of the abated
pollutant with a secondary plant. |
Italy: Absorption plant for the abatement of Ammonia from baking ovens |
The
efficiency of an abatement plants is the result given by many factors, all
concurring to achieve the final result and the most important are:
v Pollutant chemical and physical features v Internal dimension and distribution v Air velocity trough the plant v Theoretical stages and adopted real number v Polluted air humidity v Air temperature |
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The plants are
mainly scrubbers with internals in structured packing and automatic suction
system regulated continuously by inverter to obtain the best optimization of
the operating costs.