Regenerative or recuperative? Destroy or recover? Customized or prepackaged? Are you scared to choose a volatile organic compound abatement technology? With all the choices available, picking a system can be daunting. But you can simplify the process by remembering the following important points, provided from interviews with several industry gurus.

The U.S. Environmental Protection Agency prefers that process components containing VOCs be substituted with alternative substances that don't contain VOC content. While this is a worthwhile goal in theory, the substitute materials often do not behave similarly to the products they replace, says Jim Alimena, marketing manager, Glenro, Inc., Paterson, N.J. Extensive process modifications can be necessary and product quality can potentially suffer. Also, suitable substitute materials sometimes aren't available.

Both the quantity of VOCs and the concentration in an exhaust stream usually help to dictate the choice of abatement technology method. The type of VOC may also be a factor when a catalyst-based or other contaminant-sensitive abatement method is considered. According to Alimena, operating costs generally decrease in direct proportion to the concentration of VOCs fed to thermal and catalytic oxidizers, not necessarily the quantity. Charles Martinson, president of The CMM Group, LLC, De Pere, Wis., differs in opinion: "Within the converting industry, the type of VOCs commonly being used are very similar between facilities and can be destroyed by virtually all types of VOC abatement technologies. However, the quantity of VOCs do play a major role in the technology selection criteria. A process exhaust volume and its VOC concentration must be considered as the major factors in selecting an abatement technology. Poor information regarding these key factors could lead to bad selection with increased maintenance and operating costs, or even shortened equipment life."

How fast can the equipment be installed? Mohit Uberoi, vice president and general manager of the emission control business at Megtec Systems, De Pere, Wis., asks this important question. Choosing modular equipment that's easy to install can minimize field installation work, which reduces cost. "Although an equipment supplier may be responsible for field installation work, the end customer is still involved because he has to watch what's going on for two, three or four weeks," Uberoi says. Fortunately, equipment is taking less time to install. Regenerative thermal oxidizers that once took six weeks to install are now taking only days.

Martinson comments that space requirements and installation locations must be considered, but technology selection criteria should not be heavily influenced by the equipment floor plan. The systems are usually installed outdoors and can be placed on the ground, on the building roof and/or on an elevated structural-steel platform. Depending on the process airflow requirements, systems range from 8-ft wide x 20-ft long and 8,000 lbs to 40-ft wide x 60-ft long and 180,000 lbs or larger.

Do you want to be in the hazardous-materials business? This is a question converters must ask themselves when trying to decide whether to recover or destroy VOCs, says Alimena. When extremely large amounts of solvents are present in the exhaust and reclaimed solvents can be easily reused in operations, recovery can be economically viable. However, Alimena adds, "Additional regulatory requirements for documentation, storage, handling and other issues of custody and responsibility can turn a well-intentioned attempt at solvent recovery into a continuing headache."

Solvent recovery can be feasible when VOC concentration is above 2,000 ppm, process exhaust temperature is below 120 deg F and a single solvent or simple solvent blend is used. Compared to VOC-destruction technologies, they can be very large and complex, expensive to install and operate, and can require constant operating personnel to monitor and maintain the system, says Martinson.

Buying a pollution-control system is akin to buying a car, says Gordon Harbison, manager of business development and marketing, Dürr Environmental, Inc., Wixom, Mich. With some prepackaged choices, not all options or features are available.

Harbison, who sells both customized and prepackaged systems, says that a customized solution is geared to all of a customer's requirements, so that less accommodations must be made. Customization allows a converter to demand that the system fit in a certain location or have specific destruction and thermal efficiencies. Many system suppliers offer customizations at no extra cost.

A typical VOC abatement system lasts about 10 years or more. That's a whole lot of energy consumption, so be careful to choose a system with minimal energy input, and one that returns energy in the form of hot air or steam. The destroyed VOCs can be used as fuel for process supply air for web dryers and curing ovens, to heat hot oil or water coils, to make low-pressure steam or for building comfort heating.

"Instead of looking at it as pollution going up the stack, look at it as heat," says John Berger, director of marketing, Huntington Environmental Systems, Inc., Arlington Heights, Ill. "If it's a very rich stream, the heat available is approximately 1,500,00 BTU/hr. per 100 lb./hr. of organic solvent." For these process streams, heat recovery is cost effective.

If an abatement system requires supervision during operation, material replenishment, removal of captured VOCs, or frequent cleaning or adjustment, a converter must budget for labor costs and potential system downtime while maintenance is performed, according to Alimena.

For proper long-term operation, converters should implement a stringent preventive maintenance program, which they can support with their own maintenance personnel. An annual PM program could also be bought from the equipment supplier for $2,500 to $18,000 depending on the plant location and system complexity, says Martinson.

Choosing a pollution-control system can be confusing, so it's important to take a few deliberate breaths and gather all the right information before making a decision. "Don't make this decision in a hurry," advises Megtec's Uberoi. "Go out and look at a few pieces of equipment."

"Coming out on top in VOC abatement demands that you exercise careful consideration during the technology selection process, and that you solicit expert advice," comments Alimena. "With good guidance, you can meet VOC abatement requirements and devote your attention to running your business."