by Paul Wild, General Manager, Exothermics Inc.
“Pollution Control can be very expensive!” you may say. And you’d be right. It can be. With ever increasing pressure to reduce emissions of gaseous pollution (and a company’s carbon footprint), many are choosing to install fume abatement systems on process exhausts where pollutants are present. In fact, regulations require pollution control equipment for many industries.
The popularity of the Thermal Oxidization process for pollution control is, for the time being, high enough that it is considered the norm. Some companies have to endure the cost of cleaning exhausts for the environment. That is the responsibility element companies have to get used to. But it doesn’t have to be all bad news.
I would bring to your attention several possibilities of secondary Heat Recovery worthy of your consideration. Process exhaust Heat Recovery can offer exceptional payback. The right industrial-grade air to air heat exchanger, correctly designed, engineered and built for your application, can allow you to reduce negative impact on the environment and your operational energy costs – dramatically.
For instance: If you have a Regenerative Thermal Oxidizer (RTO) abatement system you know the final outgoing RTO exhaust temperature is higher than the incoming process air temperature. If, for example, you have 200°F entering the RTO from your process, the RTO exhaust could be as high as 400°F – even higher if the bypass is open. When RTOs are sold with high thermal efficiency expectations, companies often overlook the energy recovery potential of the RTO application.
Look at What’s Coming In
With all industrial thermal applications, when looking at energy recovery, you should look at your fresh air or cold process air inlets first. Try to concentrate on where you are pulling fresh air into your process, because that is the real opportunity for energy recovery. Much of the cold air currently pulled into your process could be preheated – with the exhaust from a boiler or an RTO – or straight from the process exhaust itself.
Therein lies the win-win opportunity.
The company I represent, Exothermics, has proven this win-win for over 30 years. That’s how I can discuss money-saving results with such certainty. What’s the win-win? Fume preheating for pollution control and energy savings through secondary heat recovery. The win-win is available for OEM and end user processes in industries like printing, paint drying, varnish drying, curing, metal finishing, paper, gypsum, pharma, milk drying, plastics and even industrial launders.
With Natural Gas prices as volatile as they have been, this topic certainly warrants some attention. Gas prices may fall a little in the short-term, but the trend is unquestionably up.
Help for the Burner
Exhaust fumes sent to an oxidizer for VOC destruction – whether recuperative thermal or catalytic – must enter the oxidizer at a certain temperature. Oxidization will not effectively take place unless proper temperatures are achieved. To raise exhaust temperature, a burner is usually involved. If yours is a high VOC exhaust, you have no choice but to use an oxidizer. However, to attempt to raise the temperature of process exhaust with a burner alone can be costly.
Reducing the Cost of Environmental Responsibility
Countless process engineers have found that by incorporating a gas to gas heat exchanger into the oxidation system, the exhaust can be pre-heated, raising the temperature to the point where the burner has little more to do than give the temperature a boost. This can represent a tremendous reduction in the amount of energy used by the burner. In the case of pollution control equipment, such as thermal oxidizers and catalytic oxidizers, this is without a doubt essential.
But what if you don’t need pollution control equipment on your exhaust?
No Pollution Control Equipment? You Can Still Realize Great Energy Savings
With mandates to reduce operating costs, it only makes sense to look seriously at a heat exchanger that can take exhaust air and gases out of the stack, and turn them into usable energy! A competent thermal engineering team knows how to match the right design, size and material to fit each application precisely. If that is done correctly, increased efficiency and impressive paybacks can be accomplished.
On some applications, it is a very real possibility to see your money returned and dividends coming in after three months!
Automotive Industry Led the Way
“General Motors was the first auto manufacturer to recover process exhaust,” explains Ron Leon, National Automotive Industry Manager for combustion solutions provider, Eclipse, Inc. “That was back in the 1970s. Then Chrysler and Ford saw the wisdom in investing in heat exchangers. Now, you can’t find an automotive manufacturer who’s not utilizing this powerful technology!”
What is it that the automotive industry saw that caused them to invest in heat recovery during a fairly unstable economic time? Payback. They saw the ability to capture process exhaust and use it to drive the very manufacturing processes it came from and dramatically reduce their energy costs!
They also saw the opportunity to be environmentally responsible. Even though the topic of environmental responsibility was fairly young in the 1970s, the auto makers saw in heat recovery a win-win proposition. A tough decision when times are tough. No one would argue that. But they have realized such tremendous payback, they’ve multiplied the decision over and over, until every possible process has incorporated a heat recovery system.
Hang on to Your Cash? Or Let it Pay You
There isn’t a plant manager in North America who hasn’t been challenged to reduce operating costs. An effective heat recovery system can be a key component in the success of that effort. To look at heat recovery only makes good fiscal sense. “Look!” you say, “I have got to hang onto my cash during these uncertain economic times!” I understand your concern. That is, in many cases, exactly what you should do.
It is never easy to let go of your company’s capital at a time like this. But does it really make sense to hang on to a dollar for 3, 6, or 12 months – when, at the end of that time, that dollar could be paying you $2 or $3 every year in return – for more than 10 years down the road? That, of course, is for you to decide.
Remember, once the initial capital expenditure has been recuperated, you will see cost reductions year after year. It’s so important, I’ll say it again: When a heat exchanger has been correctly engineered and built, depreciation can be based on terms of ten years or more. We’ve seen our heat exchangers in the field for as long as 20 years!
Imagine a world where no one overlooks the potential for reducing pollution – and for heat recovery. It’s just around the corner, but we are not there yet.
Carbon Footprint – What is it?
By definition, a carbon footprint is a measure of the amount of carbon dioxide emitted through the combustion of fossil fuels. A carbon footprint is often expressed as tons of carbon dioxide or tons of carbon emitted, usually on an annual basis. A company’s carbon footprint is the direct effect its actions (including manufacturing processes) have on the environment in terms of carbon dioxide emissions. Did you know that an effective heat exchanger, whether installed on a process oven, industrial boiler, regenerative thermal oxidizer, or catalytic oxidizer, will SIGNIFICANTLY REDUCE A COMPANY’S CARBON FOOTPRINT?
Even if your process exhaust doesn’t require oxidation, a heat exchanger will reduce the amount of combustion gas emissions your company emits into the atmosphere both inside, and outside your facility. This is because you’ll be burning less fuel. Not only is pollution control good for our world, it’s good for your employees as well. This becomes a win-win situation. That’s because you will also be reducing your energy costs and positively affecting your company’s bottom line. In short, the most logical first step to pollution control is to add a heat recovery system.
About the Author
Paul wild is the general manager of Toledo, Ohio-based Exothermics, Inc. a subsidiary of Eclipse, Inc. and has been manufacturing industrial air-to-air and gas-to-gas heat exchangers since 1976. Mr. Wild has been in the thermal industry for 23 years. www.Exothermics.com