Field Service Technician

Calgon Carbon's Field Services

When it comes to optimizing and maintaining your purification and production treatment units, there's no such thing as off-the-shelf services. The unparalleled expertise of our staff enables Calgon Carbon to provide our customers with quality, cost-effective solutions.  That's why, each year, hundreds of chemical, food, oil and pharmaceutical manufacturers, municipalities, remediation contractors, government agencies and many others turn to us for their service needs. In addition to being the world's leading producer and supplier of activated carbon and UV Technologies, we offer the industry's broadest range of field and technical services.  For more than 50 years, we’ve pioneered leading-edge services for drinking water, wastewater, odor control, pollution abatement, solvent recovery, ultraviolet lamp systems, and a variety of industrial and commercial manufacturing processes.

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Frequently Asked Questions

What is activated carbon made from?

Activated carbon can be manufactured from any organic material containing carbon. Commercial carbons are made from sawdust, wood, charcoal, peat, lignite, petroleum coke, bituminous coal, and coconut shells. Calgon Carbon offers activated carbon products made from bituminous coal, coconut shell and wood. We choose these raw materials in order to provide the best activated carbon to our customers.

How is Calgon Carbon's coal-based activated carbon produced?

The coal is pulverized to a very fine particle, about the size of talcum powder. The powdered coal is mixed with a binder to "glue" it back together and pressed into briquettes. These in turn are crushed and classified to the size of the desired end product. This process, called reagglomeration, creates an activated carbon that is harder and less dusty than a direct activation process. Reagglomeration also assures that the activation occurs through the granule to the core. Some direct activation processes only activate the exterior of the granule.

The sized material is heated in an oxygen void environment to avoid burning and to remove the volatile components of the coal. The carbon is activated by additional heating in a controlled environment of oxygen and steam. The activation process creates a highly porous graphitic plate structure with tremendous surface area.

How much surface area does activated carbon have?

A single pound of activated carbon has a surface area equal to 125 acres.

How much does it weigh?

Pure carbon weighs about 130 pounds per cubic foot. It is much denser than activated carbon. During the manufacturing process, the structure is "opened up," creating porosity (pore volume) inside the granule. The finished product has a density between 25 to 40 pounds per cubic foot.

How much void space is in carbon?

A container of carbon is roughly 20% carbon, 40% interstitial space (the volume between the carbon granules), and 40% pore volume (the volume inside the carbon granules). Another way to visualize this is: If you had a 55 gallon drum full of dry carbon, you could add 44 gallons of water to the drum before it would overflow. Therefore, 80% of the drum volume is air.

In liquid applications, why is it important to deaerate (fully wet) the carbon?

A container of carbon is roughly 20% carbon, 40% interstitial space (the volume between the carbon granules), and 40% pore volume (the volume inside the carbon granules). If air remains in the pore volume, the fluid being treated cannot migrate to the adsorption sites. The air becomes a barrier to the carbon functioning properly.

How long does it take to fully wet the carbon?

Typically, Calgon Carbon recommends filling the system with the fluid you will be treating and allowing the system to sit idle for 24 hours. This time will allow the fluid to displace all of the air in the pores of the carbon. After the system has been idle for 24 hours, the next step is to use an upflow backwash to displace any air that has been trapped in the carbon bed. This backwash will also remove most of the carbon fines in the system.

What is this pore space?

The pore space is the internal volume of the carbon granule. It consists of all the cracks and crevices created when the coal is crushed and glued back together, and the volume between the graphite plates. The distance between the graphite plates determines whether the space is an adsorption pore or a transport pore.

What is an adsorption pore?

Adsorption pores are the internal volume where the graphitic plates are very close together creating a higher energy. Higher energy is important to adsorption because it is the energy that "holds" the contaminant (the carbon "adsorbs" the contaminant). The volume is where the graphite plates are far apart and the cracks and crevices make up the transport pores. It is important to note that all adsorption takes place in the adsorption pores and not the transport pores.

What do you mean – an adsorption pore is a higher-energy area?

There is a natural attractive force between all things in the universe. Gravity is one of these forces. In adsorption theory, the force between the contaminate and the carbon is the adsorptive force. It technically is a Van der Waals force. It is this attractive force that enables adsorption to occur. The forces are a function of the distance between the two objects. The closer together the objects are, the higher the attractive force is. The higher the attractive force, the higher the "energy" level of the pore space.

What is a transport pore?

Transport pores are the internal volume of the carbon granule where the graphitic plates are far apart or the cracks and crevices of the particle. The transport pores act as the "highways" for the contaminants to reach the adsorption pores where they are adsorbed. It is important to note that no adsorption takes place in the transport pores. Transport pores are vitally important, as they allow access to the adsorption pores – especially those deeper within the carbon granule.

How does the carbon remove the contaminant?

Once the contaminant enters the carbon granule via the transport pore space, it diffuses into the carbon matrix until it enters the smaller pores where the adsorptive forces begin to take effect. Once it reaches a higher-energy area, it can no longer migrate (or diffuse) because the adsorptive force is stronger than the diffusional force. The contaminant is adsorbed to the carbon surface by the adsorptive forces (the Van der Waals forces). In this state, the contaminant is referred to as the adsorbate.

How much adsorbate can the carbon adsorb?

The amount that the carbon can adsorb is dependent upon the type and concentration of the adsorbate. Generally, the higher the concentration and the larger the molecule, the greater the amount adsorbed. The typical range experienced is about 1 to 35 weight percent. That is, one hundred pounds of carbon will adsorb 1 to 35 pounds of contaminant. When the maximum amount of adsorbate is on the carbon, the carbon is referred to as being spent or exhausted.

What happens when the carbon is spent?

The concentration of the adsorbate in the outlet from the carbon column increases as the carbon becomes loaded with adsorbate. The adsorbate concentration increases until the outlet concentration is equal to the inlet concentration because the adsorption pores are filled with contaminant. For more information on spent carbon, click here.

How do I tell if my carbon is spent?

The only sure way to tell when the carbon is spent is to test the outlet of the carbon column for the contaminant being removed. Once the concentration of the contaminant is above the acceptable emission or discharge limits, the activated carbon is considered spent. The activated carbon does not change color or shape as it adsorbs contaminants. Therefore, no visual inspection will tell you if the carbon is spent. Also, you cannot "test" the carbon for being spent using commercially available "carbon testers", as each situation is unique based upon the type and concentration of contaminants. The only way to determine if the carbon is spent is to detect the contaminant in the outlet of the carbon column. For more information on spent carbon, click here.

How large should the system be?

The size of the system depends on the nature of the contaminant being removed. The contaminant has an adsorption potential that depends on the type of compound and its chemical structure. Some contaminants are strongly adsorbed; some are not. The more strongly adsorbed (the higher the adsorption potential) a contamination is, the less carbon is required to adsorb it. The amount of carbon required to remove the contaminant from its inlet concentration to the desired level is termed the mass transfer zone (MTZ). The system has to be at least as large as the MTZ for good carbon utilization. In situations where the MTZ is very large, the adsorber may need to be relatively large compared to the flowrate, not only to contain the MTZ, but also to get better utilization of the carbon. Calgon Carbon can help you determine the appropriate size system for your particular application, determining the minimum size equipment, type of carbon, and optimizing the balance between system sizes and operating costs.

Is there a benefit to operating fixed beds in series?

There is. As the MTZ progresses through the carbon fixed beds, it reaches a point where the length of the MTZ is longer (deeper) than the remaining depth of the carbon in the vessel still capable of adsorption (not spent). At this point, the concentration of the contaminant begins to increase in the outlet of the carbon bed as the MTZ begins to exit the vessel. This is called breakthrough. If the vessel is taken out of service when this occurs, there may be a substantial amount of carbon that had not been fully utilized.

With the fixed bed in a series, the leading edge of the MTZ would progress into the second vessel. When the MTZ wave front completely exits the lead vessel, all of the carbon in that vessel would be spent. By operating in this manner, it is possible that 100% of the carbon capacity to adsorb the contaminant would be used.

When the lead (or first) carbon bed is spent, the vessel is removed from service and the spent carbon removed for reactivation. The vessel that had been in the second (or polish) position is placed in the lead position and another vessel containing fresh or reactivated carbon is placed on line in the trailing (or polish) position.

What type of equipment does Calgon Carbon offer?

Calgon Carbon has a wide range of equipment for both liquid and vapor applications. Systems can be custom designed to fit any application. For more information on Calgon Carbon's adsorption equipment, click here.

What if I only need equipment for a short time?

Calgon Carbon provides temporary equipment through service arrangements. With these arrangements, the customer pays an initial fee whenever a service unit is shipped to the site and a monthly fee for every month the unit is on-site. For most of our equipment, a whole new unit with new carbon is shipped to the site to replace the old unit when the carbon becomes spent. The old unit then functions as a transport container for the spent carbon and is shipped back to one of our reactivation facilities, where the carbon is removed from the unit and reactivated. For larger equipment, the spent carbon can be replaced through the use of our Calgon Carbon Service Trailers. Note: Longer-term use of CCC owned equipment is also available.

For many of our customers, a service arrangement offers many advantages. Service arrangements avoid capital costs associated with having to buy the equipment or with having to manage the used equipment if the project is not a permanent installation.

How do I estimate how long my carbon will last?

Calgon Carbon has proprietary models that we use to estimate the carbon use rate (how quickly the carbon becomes spent). If you provide the flow, contaminants and inlet concentrations, we can provide a fairly accurate estimate on the carbon use rate. This can then be used to estimate the costs of using activated carbon for your particular application. We have a questionnaire that you can fill out to request a carbon usage rate estimate from us.

What do I do when my carbon is spent?

When carbon is spent, it can either be landfilled or sent back to Calgon Carbon for reactivation. Smaller service equipment can be sent back to one of Calgon Carbon's reactivation facilities with the service unit acting as the shipping container for the spent carbon. We can ship a new service unit to your site if additional activated carbon is needed. For larger Calgon Carbon service systems or purchased equipment, contact your Technical Sales Representative or a Calgon Carbon Operations contact. They can help you make the necessary arrangements for exchanging the carbon at your site. Note: Calgon Carbon is the only provider of two RCRA-permitted facilities.

An important point with returning spent carbon to one of our reactivation facilities is carbon acceptance. Each application at each site is required to have a carbon acceptance number before we are able to accept the spent return. For more information on spent carbon, click here.

What is carbon acceptance?

In order to comply with the requirements of our operating permits and to ensure safe handling and reactivation, Calgon Carbon cannot accept the return of any spent carbon until the material has been tested and approved. The first step in obtaining Carbon Acceptance is to send us an Adsorbate Profile Document, which describes how the carbon has been used, and a representative spent carbon sample for testing. After the testing has been completed and approval has been given, you will receive a Carbon Acceptance Number (CAN). This number will be used for the life of the specific project and must be given to our Customer Service representative when you call to obtain a Return Materials Authorization and schedule a return. Carbon acceptance testing for that project need not be repeated unless there is a change in the process.

The approval and CAN is site and application specific. If you are using carbon in more than one application, approval for the return of spent carbon and a CAN must be obtained for each project. For more information on carbon acceptance, click here.

What types of applications are right for activated carbon?

Activated carbon is principally used to remove low-levels (ppm or ppb level) of organic species from water, process liquids or air. If the concentration is in the percentage level (1%, 5%, etc.), activated carbon may or may not be appropriate for the application. Information on the applications for Activated Carbon can be found under Find a Solution on the left-hand side of the toolbar.

What is reactivated carbon?

Reactivated carbon is formed through a thermal treatment process in which adsorbed chemical constituents are removed from spent activated carbon to produce a recycled, reactivated product for beneficial reuse by Calgon Carbon's customers. For further information on reactivated carbon, click here.