One day next spring, people living and working in Phillipsburg, NJ, will see something they’ve never seen before: a “smoke-free” skyline. And, if everything works according to plan, metalcasters across North America will see something many of them never thought they’d see: an emissions-control system for a cupola melt shop that substantially eliminates mercury emissions.
That’s the goal of the $9.5-million capital investment
Atlantic States Cast Iron Pipe Co. (ASCIP) launched last spring. And, even though the plant is currently in compliance with New Jersey’s stringent standards for mercury emissions, and even though mercury is not covered by the U.S. Environmental Protection Agency’s Maximum Achievable Control Technology regulations for cupola melting, the ambitious goal has been set because it’s seen as having strategic advantages in a changing market.
Catching up with history
Atlantic States Cast Iron Pipe has been operating since 1856. Originally, the Warren Foundry and Machine Co. was established to produce castings for railroad construction and maintenance, and various other general application, but within a year it had begun producing pipe products. In 1951 it initiated centrifugal casting, and since 1975 it’s been a part of the McWane Inc. organization. Like other operations in that group it’s recognized as a leader in the production of ductile iron pressure pipe. ASCIP distributes these products to customers in the Mid-Atlantic States, New England, and Canada, in sizes from 3 to 36 in.
ASCIP sits in downtown Phillipsburg, at the heart of that Delaware Valley town of 15,000. Today, the plant uses a Venturi system to clean fugitive emissions from its cupola melting process. The smoke trailing over Phillipsburg is actually steam: it’s vapor rising from the water used to cool the Venturi scrubbers, and creating a plume that’s visible all across town.
The neighbors may think ASCIP has stopped operating when that steam disappears, Mitchell Kidd supposes, but with the first-of-its-kind baghouse system being installed now, the plant will have become a new sort of landmark.
Kidd is vice president and general manager of ASCIP. In a recent interview he explained how the investment in new technology and equipment is actually a follow-through to multiple efforts to work with state and local officials, and residents and key stakeholders in the community. The aim was to spread awareness about ASCIP and its operations, to promote goodwill and generate cooperation over the long term.
Operating a foundry anywhere presents regulatory challenges, but in New Jersey it’s particularly tough to do.
ASCIP has had its own problems maintaining compliance with environmental regulations, and that fact makes it perhaps even more necessary to succeed with this new investment, in order to burnish its community and customer relations.
Atlantic States produces ductile iron in its cupola, stoking it mainly with automotive scrap. A significant problem for any foundry or steel mill melting automotive scrap is mercury; the element is used widely in automotive design for hood and trunk lights, high/low beam switches, and in some anti-lock brake systems. It’s generally expected that these mercury sources are removed by scrap processors, but there’s no certainty, and reducing mercury is a goal for numerous environmental agencies.
To date, the U.S. EPA has not included mercury in its standard for iron and steel foundries, but last December, the New Jersey Dept. of Environmental Protection finalized its standards for mercury air emissions. The rule stipulates that foundries and steel mills in the state must achieve a mercury emission rate of 35 mg/ton of steel produced by purchasing mercury-free scrap, or 75% control efficiency by installing and operating add-on controls. These new standards take effect January 1, 2010.
For Atlantic States this means it must reduce its mercury emissions from approximately 52 lb/year to approximately 12 lb/year. Last March, with the support of ASCIP and other industrial interests, New Jersey instituted a mercury-switch removal bill that requires auto dismantlers to remove the switches, establishing a bounty for each switch recovered and obligating the automakers to pay the dismantlers’ cost to for the removal.
“We co-sponsored that bill,” Mitchell Kidd recalls, “and it was an interesting coalition of regulators and environmental groups, and industry. However, Atlantic States’ belief, and my belief, is that that will go a long way but it will not be enough.”
Venturi systems like the one ASCIP now uses direct furnace off-gases through a radial channel, accelerating them while subjecting them to a water spray. The high velocity atomizes the water into a fine mist, and the turbulence causes “collisions” of the droplets and particulates in the furnace emissions. The agglomerated waste is collected, and separated in a later stage.
Such systems work but they consume a lot of energy, among their other attendant costs. In the case of ASCIP’s cupola, the system will not capture mercury to the degree of the emerging New Jersey standard. This is chiefly because mercury, a volatile organic compound, is combusted at the high temperatures at which the Venturi operates. The company concluded it needed to pursue a new emissions-control system, because no add-on control technology has been demonstrated to reduce mercury emissions significantly from a foundry cupola anywhere in the world.
The new baghouse system, designed and supplied by Kuttner L.L.C. (www.kuttnerllc.com), is significantly advanced over the sorts of baghouses that have been available for decades. Kidd explains that most such systems operate in the range of 500°-600°F, while the new Kuttner design will operate at around 280°F. “That was attractive to us,” he says, “we think that’s going to be critical to getting the mercury out.” The lower operating temperature will also save energy and maintenance costs.
How will it work?
The Kuttner system will receive emissions from ASCIP’s 114-in. cupola that operates in the range of 60-65 tons/hour, according to Kidd, though it’s rated to produce in the 80-tons/hour range. Off-gases will pass through a recuperative hot-blast unit that will recover a significant volume of the heat energy to preheat combustion air. Then, the gases will proceed to a gas cooler.
“Some older baghouse systems would use water to cool the gas,” Kidd relates, “but water has an adverse impact on the life of the bags, and thus the function of the baghouse.
“Our system is unique in that it uses oil cooling, kind of like a big radiator that will circulate oil in the 500°- 600°F range, that will cool the combustion gases down to the 280°F inlet temperature of the baghouse. And that provides us with a lot of opportunities,” Kidd explains, in anticipation. Foremost, he says, will be very precise temperature control. That, along with the system developer’s experience with mercury removal, was a critical selling point for ASCIP.
Another critical selling point was the prospect of mercury removal. Kuttner indicates the mercury and particulate-reduction technology was designed by Luehr Filter GmbH, which has developed over 100 mercury-reducing projects around the world.
After the emissions are past the gas cooler, several reagents are introduced to condition the gases. “The heart of the system,” Kidd states, “is its use of powdered activated carbon.”
PAC is a highly adsorbent form of carbon that’s been adopted for industrial use to remove odors and toxic substances from liquid or gaseous emissions. For example, in waste treatment it removes dissolved organic matter from waste drinking water. It’s also used for motor vehicles’ evaporative control systems. It’s used by the waste-management industry to capture organic material escaping from its incinerators. At ASCIP it will be adapted to a cupola system to capture mercury emissions. By injecting it to the off-gas stream the carbon bonds with the particulate matter to capture material that otherwise would escape the control system entirely.
“PAC is a technology that’s been around for some time,” Kidd points out. “If you look at it under a microscope it’s really a big sponge. It’s got a lot of surface area ... it’s a very fine material offering a lot of intimate surface contact. The trick, metallurgically, is to convert the mercury into a form that is adsorbed on the surface of the activated carbon. And, then, the activated carbon is collected in the baghouse.”
The PAC technology may have precedent, but this will be the first such application in North America. ASCIP claims the application and operation will be “technology-forcing,” surpassing the EPA’s MACT standards for iron foundries and establishing a new state-of-the-art for mercury controls in metalcasting.
Plan in progress
Construction is underway at the Phillipsburg site, with only minor disruptions to the ongoing operation at Atlantic States. By late summer the foundations had been poured, steel structures were going up, and the baghouse hoppers were due to be installed. The project was on track for the system to be in place for testing at Thanksgiving time.
“One of the benefits of doing this is that we can build the system while we’re running the old system,” Kidd points out, “and then we’re planning a three-week outage in December, when we’ll make the tie-in.”
The new baghouse is just part of Atlantic States’ effort to anticipate the environmental demands on producers in its market, so it can succeed as a supplier there. It has recruited a new environmental engineering director, Dennis Zurakowski, whose +20-year career includes experience in mercury recycling; and a new senior environmental manager, Jeff Smith, who has nearly 20 years experience that includes work with heavy metals (lead, mercury) in battery manufacturing. “I expect this new project to be very challenging,” says Kidd. “When you’ve got a long tough row to hoe, you need a lot of smart people around you.”
When the new baghouse is in place next year, ASCIP expects to realize benefits beyond the mercury control. It anticipates its CO emissions will drop by 60%, and that particulate emissions will decline “by an order of magnitude,” according to Kidd.
Using PAC may help to contain volatiles other than mercury, such as arsenic, cadmium, chromium, lead, nickel, and manganese. And while there are no guarantees, this prospect has led to an agreement with state regulators to conduct tests that will help establish the permit limits for these substances after the fact.
Other goals are more pragmatic. “We expect the system, through better controls, will reduce natural gas usage,” says Kidd, “and we expect to reduce our electricity consumption by approximately 25%.” By cutting down its gas consumption, NOx, CO, and CO2 emissions should decline.
Beyond the baghouse installation, Atlantic States has agreed to develop and implement a continuous emission-monitoring system for mercury. “At least, we will develop the feasibility of a CEMS,” ASCIP. New Jersey already requires foundries to operate CEMS for CO and CO2, and while no one has developed a CEMS for mercury that remains a goal beyond the start-up of the baghouse system.
One reason that electricity consumption may be lessened is that the new baghouse operates with a much lower air-pressure drop than the Venturi system, and as a result it doesn’t require enormous, high-pressure fans. “We’re going to reduce our primary exhaust fan from 1,250 hp to 700 hp,” Kidd reports.
But there will be a trade-off. The present system uses a fan with a capacity of about roughly 40,000 cfm; the new system will have a 60,000-cfm fan. “It’s a much bigger system,” Kidd explains, “a very large baghouse: 1.0 velocity cloth ratio, which is a measure of how fast the air will go through the filter bags. That’s kind of critical, because the slower the velocity, the longer the reaction time. If you’ll recall, it’s reacting with the PAC on the surface of the filter bag, so we need a really big baghouse.”
Overall energy-cost savings may be significant. Whereas water sprays cool the gases in the Venturi system, the
Kuttner process will have oil running through cooling tubes. The oil is heated to about 600°F, and then recirculated through a cooler that blows air over a set of fins to cool the oil down. “Just by recirculating oil we will have an opportunity to recover about 60 million Btus/hour,” Kidd anticipates.
“We can skim off a slip stream of this for heat reclamation. We’re going to do a couple small projects initially. We’ve got some building heat applications we may try, and some pipe curing.”
Reasonable and feasible
There is a high sense of anticipation at Atlantic States, as well as a sense of drama. They know what they’re doing has not been done before, and that the future of the organization is in play. If the project succeeds, it may also reshape the regulatory landscape. “The New Jersey standard is more stringent than MACT,” Kidd indicates. “MACT for cupolas does not include mercury ... In fact, a lot of foundrymen worked on that MACT standard and we’ve not made many friends in the industry by being the first to implement these controls.” He believes its possible that EPA may cite ASCIP’s standards as “reasonable and feasible,” meaning other foundries now challenging the MACT standard as unachievable would have their arguments undermined.
Certainly the expectations are high. “Atlantic States has positioned itself to be beyond compliance from a regulatory standpoint,” Mitchell Kidd generalizes, but goes further. “We want to be the premier supplier of ductile iron piping in the Northeast. And, the Northeast is very concerned about environmental impact. ... We expect to dominate the market.”
No one knows exactly what to expect, and the results of the Atlantic States project will be evaluated in various ways — as a cupola melting operation, as an environmental-control effort, and perhaps as a standard for environmental control technologies. Until any of that is known, for the folks in Phillipsburg clear skies may be enough.
Expected benefits of Atlantic States Cast Iron Pipe’s emissions control project
• Reduce CO emissions by ~60%
• Reduce particulate emissions
• Reduce arsenic, cadmium, chromium, lead, nickel & manganese emissions
• Reduce natural gas use by ~10%, thus reducing NOx, CO, and CO2
• Reduce electricity consumption by ~ 25%, thus reducing NOx, CO, and CO2 emissions
• Eliminate fan upsets, associated citizen complaints to the NJDEP
• Improve dispersion from the stack since the temperature will be higher
• Reduce waste disposal by approximately 40 tons per day
• Improve beneficial reuse of the dry material collected from the baghouse
• Allow waste heat recovery, reducing plant wide NOx, CO, and CO2 emissions
• Reduce offsite noise from the elimination of the high-pressure scrubber fans
• Eliminate the visible steam plume, and reduce the odor that accompanies it.