Activated Carbon


Activated Carbon

Activated carbon, is a porous solid surface material which can merge with different molecular structures. Activated carbon's interaction can only be physical (the interaction between the atoms that are not connected to each other or Van der Waals forces interaction), or may be due to physical-chemical structure force depending on the activated carbon; or depending on the type of molecule, and are subject to change. Activated carbon generally produced with the activation process with steam. This process of carbon or carbon-containing the starting materials react with steam or other oxidizing material is passed from the process gas by grouping. Charcoal, coal, lignite, coconut-based coal, peat or wood-based charcoal is used as raw materials.

In addition, to activate the raw materials, cellulose-based raw materials and chemical activation process can be used. For example, wood shavings treated with chemicals at high temperature which have a dehydration effect. As a result of the whole process, that may vary between 500-2000 square feet in a gram of carbon, a porous activated carbon with greatly enhanced surface area is obtained.

Lapis Kimya serves to industry with different product options with differerent features, shapes and sizes (granular, extruded or powder) in order to meet different needs of the market.

About Activated Carbon

WHAT IS ACTIVATED CARBON?

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Activated carbon, is a porous solid surface material which can merge with different molecular structures,. Activated carbon's interaction can only be physical (the interaction between the atoms that are not connected to each other or Van der Waals forces interaction), or may be due to physical-chemical structure force depending on the activated carbon; or depending on the type of molecule, and are subject to change. Activated carbon generally produced with the activation process with steam. This process of carbon or carbon-containing the starting materials react with steam or other oxidizing material is passed from the process gas by grouping. Charcoal, coal, lignite, coconut-based coal, peat or wood-based charcoal is used as raw materials.

In addition, to activate the raw materials, cellulose-based raw materials and chemical activation process can be used. For example, wood shavings treated with chemicals at high temperature which have a dehydration effect. As a result of the whole process, that may vary between 500-2000 square feet in a gram of carbon, a porous activated carbon with greatly enhanced surface area is obtained.

THE SURFACE AREA OF THE ACTIVATED CARBON

The effectiveness of activated carbon depends on the surface area. As the surface area increases so as the activity increases. The surface area of activated carbon typically varies between 500-2000 square feet.

THE UNIQUE FEATURE OF COCONUT-BASED ACTIVATED CARBON?

Coconut-based active carbon is considered The most effective active carbon ever made.

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  • The surface of this activated carbon is quite porous and surface area is quite big.
  • Porous structure is suitable for a quick adsorption
  • Is a raw materials that is found in nature
  • There is no carbon emission
  • High in hardness
  • Impurity is yery low.

WHAT IS ADSORPTION?

aktif-karbonAdsorption is the adhesion of the molecules of a substance to the surface of the activated carbon.Activated carbon is characterized with high micro-and macro-pores that allows adsorbents to attach to the inner surface of activated carbon There are two types of adsorption.

Physical adsorption:
Physical adsorption, with Van der Waals force between the molecules, material to be adsorbed hold on to the internal surface area of activated carbon. Gravitational force decreases, as the distance between the pore walls and the molecules increases.

Kemisorbsiyon:
This is accomplished by the strong bond between the adsorbate molecules and the chemical complexes that are impregnated into the pore wall of the active carbon.

WHICH INGREDIENTS ADSORBED WITH ACTIVATED CARBON?

Activated carbon is usually used for adsorbtion of organic materials. At the same time, some inorganic ingredients that has heavy molecular weight such as iodine and mercury can also be adsorbed.

Adsorbing capacity of activated carbon increases;

a) as the molecular weight increases
b) as the number of functional group increase
c) as the polarity (polarization) increases.

WHAT IS GRANULAR ACTIVATED CARBON (GAC)?

Granular activated carbon is the ground and sieved state of the active carbon with irregular shape. Granular activated carbon is used to purify high bulk gas or liquid substances. Granular activated carbon powder is harder and longer lasting than active carbon. It can be used reactively several times.

WHAT IS POWDERED ACTIVATED CARBON (PAC)?

Powdered activated carbon is usually used in applications liquid phase or flue gas. Distribution of particles in powdered activated carbon usually varies between 5-150 micrometers. Can be used in a discrete or continuous process. Powdered activated carbon neither be reactivated nor can be re-used like granular activated .

PROPERTIES OF ACTIVATED CARBON

Surface Area:
surface area of activated carbon varies between 500-2000 m2/g. This means, only 3 grams of activated carbon may have a surface area as big as a football field. The surface area of carbon substances can be expanded with activation process.

Total Pore Volume (TPV):
TPV, refers to the total volume of the space created by the pores within an activated carbon. The effectiveness of activated carbon increases as the total pore volume increases and it is expressed in ml/g.
Distribution of Pore Volume :
The property of the activated carbon is measured by the distribution of the pore size. In the decolorization applications active carbon with a high dispersion ratio mesaporate is required.

Pore Volume Distribution:
The property of the activated carbon is measured by the distribution of the pore size. In the decolorization applications active carbon with a high dispersion ratio mesaporate is required.

SELECTION CRITERIA of ACTIVATED CARBON

• Abrasion resistance
• Adsorption capacity
• Distribution of particle sizes for optimum flow
• Adsorption and desorption rate
• Compliance with the field of use of the product
• Substances that can interact or may be effective during the loading of Carbon

CONDITIONS THAT MAY AFFECT THE PERFORMANCE OF ACTIVATED CARBON

  • Different Raw materials
  • Status and size of raw materials
  • Activation feed rate
  • Activation temperature and pressure
  • Oxygen content during activation
  • The mixture of final product

Lapis Kimya serves the industry with a variety of products (granule, extruded or powder) with different properties, shapes and sizes to meet the needs of many applications.

 

Usage

Activeted carbon is quite widely used in water treatment area throughout the world. The operation process of surface or underground water purification usually requires the use of activated carbon. For this application granule (GAC) or powdered activated carbon (PAC) form is used for removal of bad taste and odour in pure water. Activated carbon is used in to purify the water to the highest level and get rid of the chlorine in order to be used in mineral water industry along with beer and soft drinks industry.

Activated carbon is used to purify wastewater, also used in the final stage of clearing industrial wastewater from polluters such as paints, surfactants, hydrocarbons etc.
Activated carbon is usually used in dust form in conjunction with biodegradation process in these kinds of application areas.

A remarkable decrease is observed on surface foam when the carbon is dosed in ventilation tank. Detergents and other organic materials quickly adsorbs on the surface of activated carbon.

In addition, the granular activated carbon is used for drinking water treatment and chlorine treatment operations, and also used in the filter tank of wastewater treatment plants. Granular activated carbon is also suited to eliminate organic substances that are dissolved in the water but cannot be disintegrated biologically for relief.

The use of activated carbon in the purification of water for human consumption, provides suppression of dissolved organic substances in even very low concentrations.
For this purpose Lapis Kimya offers granular activated carbon (GAC) which can be reactivated, in order to eliminate organic materials, residual chlorine, ozone and trihalometan. Dosed powder activated carbon (PAC) is offered prior to liquid/solid processes(filtering etc) which is used to eliminate of dissolved organic substances and fragrances.

In wastewater treatment, activated carbon is used in the last step to remove dissolved organic materials, surfactants and hydrocarbons, which generally give a color to the water. In this field of application, granular activated carbon can be used in fixed beds, while powder activated carbon can be used in filter media for liquid / solid separation.
The most common practice in wastewater treatment is to use the powdered active carbon into ventilation tanks to remove organics with the biodegradation process, to improve nitrification to minimize foam formation, and to improve sludge settling.

In this application, granular activated carbon (GAC) is used for the separation of organic substances such as hydrocarbons from condensate water recycled to the boiler feedwater. This proactive activated carbon is used to protect the resin from contamination with organic substances and to reduce the regeneration frequency of the resin.

In water treatment processes, water should be disinfected with chlorine. The residual chlorine must be removed from the process water by filtration with granular activated carbon (GAC). The excess chlorine enters the redox reaction with the activated carbon forming irreversible amounts of hydrochloric acid. The chlorine removal capacity of the activated carbon is referred to as dechlorination half-life" and refers to the depth of bed required for the chlorine concentration in the beginning to be halved.

Often water sources are contaminated by high amounts of organic matter. Pollutants are mostly hydrocarbons originating from refineries and petrol stations. In such processes, selected granular activated carbon in terms of correct adsorption capacity and particle size properties yields highly efficient, long lasting and efficient results in the removal of hydrocarbons.

Lapis Kimya also supplies activated carbon for customers who make air and gas treatment. Lapis Kimya offers solutions to customers other than air and gas, in order to eliminate specific pollution in some cases. An important feature of active carbon used in such applications is the ability to retain organic and malodourus molecules. This feature is basically based on fine micropores that catch pollutants. The holding capacity of actived carbon pollutants can be calculated by benzene or carbon tetrachloride indexes, which give an idea of the activity of actived carbon. Recently, the butane index is also used to calculate the activity of the actived carbon that is used for gas treatment. The most common problem with gas treatment is the low adsorption of low molecular weight toxic substances to actived carbon, mostly in the inorganic structure. Such examples can be, small amount of hydrogen sulphide or acidic or alkaline polluted air can be found in natural gas. These compounds usually form together with the adsorbed organic vapor. In such cases it is possible to use actived carbon impregnated with different chemical products which can bind low molecular weight toxic substances; or convert them into odorless form which is not volatile.

The long-term potting process of agricultural and easily degradable products is possible by the controlled and slow ripening of the metabolism of vegetables and fruits.
During cold storage, these products form carbon dioxide gas and this carbon dioxide which accelerates decomposition must be removed from the environment.
In these processes activated carbon is used to adsorb carbon dioxide in order to prevent degradation in cold storage areas, and also to minimize losses and to prolong storage time.

In order to comply with the directives on atmospheric emissions, activated carbon filter must be installed at the ventilation outlets of the paint booths. This application area requires a filter installation with at least 150 kg of extruded activated carbon.

 

Active carbon technical report