Cutting Caustic

FROM THE APRIL ISSUE: In collaboration with Ecolab, Badger State Ethanol has removed caustic soda from its front-end cleaning process.
By Matt Thompson | March 20, 2019

When Stephanie Schmidt, process analyst and plant chemist at Badger State Ethanol in Monroe, Wisconsin, first heard of plans to try a new cleaning process at the plant, she was more than a little skeptical. “I thought they were insane,” she says. “I thought they were going to infect my fermenters. I thought that we were going to lose yield. I thought they were crazy. I was probably one of the biggest sceptics about doing this because I just didn’t think it was possible.”

But the year-long collaboration with Ecolab for cleaning fermenters, coolers, condensers and syrup lines is complete, and Schmidt is fully onboard with the process. “They proved me wrong,” she says.

The major feature of Ecolab’s approach is removing caustic from the cleaning process. Schmidt explains that the plant still uses caustic to clean the evaporators but cleaning the fermenters, exchangers and coolers is done without it. “Everything about caustic is a pain,” Schmidt explains. “I mean it foams. If you don’t flush it out enough, you can get high sodium levels that will cause issues with your fermenters. Caustic has been an industry headache that we all just dealt with because none of us had a better way to clean.”

Zach Babcock, associate district manager at Ecolab, says the company has a more collaborative approach to ethanol plant cleaning that relies on a partnership. It worked well with Badger State.

“Kudos to their general manager and CEO, Erik Huschitt,” Babcock says. “He really bought in and believed, ‘Ok, we spend X a year cleaning. Our core competency’s not cleaning tanks, pipes, lines, etc. How much better can we run the operation if we partner with a vendor whose core competency is CIP (clean-in-place)?’”
Schmidt agrees. “We thought, ‘Well, they’re kind of the experts. Why don’t we let them take a crack at helping the ethanol industry clean a little better?’” she says. “So that’s what we did, and it’s been really, really neat so far. Their support has been really good. And they’ve really guided us from a chemistry and training, and that complete package that you would want from a partner.”

That collaborative approach to cleaning and plant operation is important because the needs of each plant are different, Babcock says. “We actually ended up being pretty nimble and kind of looking at every plant going, ‘You tell me what you’re trying to accomplish out of this,’ and we’re looking from a partnership standpoint: How can we best support the plant’s goals? And on our end, that’s through developing and implementing the most effective cleaning program.”

Downsizing Downtime
Schmidt says the collaboration with Ecolab began when Badger State contacted Ecolab to help clean evaporators. Badger State was pleased with the service provided, and Babcock expressed interest in partnering to try a new approach.

After the evaporators, Ecolab helped Badger State tackle the fermenters and the mash exchanger, using a final rinse cleaner in place of caustic. Schmidt says the chemical used isn’t technically classified as a sanitizer, but it performs similarly without requiring flushing. “We leave the chemical residual in the fermenters and we don’t have to flush it out like caustic, so that helps with water balance,” she says. “And when we first start putting that mash into the fermenters, that initial mash is sort of sterilized, or the bacteria is killed, and when we put our yeast in, it gives them a head start.” The cleaning method, Schmidt says, has also lowered the plant’s level of organics to below quantification.

Ecolab also helped clean the tricanters, reboiler, plate-and-frame heat exchangers and syrup lines. “Our tricanters, our clarifiers, our stack coil—we can run all of these things longer without fouling,” Schmidt says.
The reduction of caustic has had other benefits as well. “We’ve seen less glycerol in the fermenters, probably on the order of maybe 10 percent or so,” Schmidt says. “Sodium is way down. So, between the organic acid and the very low sodium that goes through the plant, we credit those two reductions in lowering our glycerol.”

The cleaning regimen also keeps the plant cleaner longer, Schmidt says. “The efficiencies come in when we don’t have to take equipment down to clean it and we can run it longer. We don’t have to take an evaporator down for 12 hours to clean it anymore.” The Ecolab process takes only four to five hours, she adds.

Schmidt says the new cleaning process has eliminated the need for hydroblasting the evaporators, syrup lines and reboiler. “There’s a significant cost savings for the facility when you don’t have to pay for hydroblasting.”

Not One Size Fits All
But Badger State’s new cleaning process might not be suitable for all plants. The final rinse cleaner that’s used in place of caustic isn’t compatible with carbon steel, Babcock says. 

Because some plants either can’t or don’t want to remove caustic from their cleaning program, their current cleaning practices will still be preferred methods of cleaning for many of them, Babcock says. “It’s not just one size fits all. Every plant’s not going to have the same goals that Badger State had. Every plant looks at this stuff differently.”

Loyd Phillips, vice president of Seneca Cos. Inc.’s waste solutions division, says automated hydroblasting is ideal for certain areas. “It is the wave of the future because the industry is very safety-minded, very safety-conscious,” he says. “All you’re really doing is eliminating the human error from things, so you get a better product. It’s a safer way to work because you’re not in the blasting zone.” In automated hydroblasting, the operator doesn’t need to enter confined places and isn’t in danger of being sprayed with water and hazardous chemicals.

Phillips compares automated hydroblasting to playing a video game. “We set up the equipment, we get out of the confined space, then it’s run off a control panel, and you have a screen in front of you. So, you’re operating almost like a joy stick.

“Our clients love it also,” Phillips adds. “Just the safety factor. Nobody wants anybody to ever get hurt. Never. Never, under any circumstances.” He adds that automated hydroblasting is also more efficient because it’s more controlled.

Expert Advice
While Schmidt was skeptical of Ecolab’s approach at first, she’s a strong supporter now. And she’s not the only one. Babcock says the company has started working with several ethanol plants, with plans to work with more soon. He says none of the plants have seen a degradation of cleaning performance since the removal of caustic cleaners.

While eliminating caustic may not be right for every plant, Babcock says Ecolab’s mission is to help plants meet their goals. “Every one of these I’ve tried to help with their customer setup, it’s not just, ‘Here’s a tote, try it,’” he says. “We’re here to help you meet your goals. So, hey, if there’s something you don’t like, let’s switch back, reevaluate the data and figure out how to move forward together, because cleaning’s a very dynamic process.”

In addition to realizing efficiency gains and improving performance, Schmidt says Badger State appreciates the expertise that comes with hiring a cleaning expert. “We’re experts at making ethanol,” she says. “Why not hire an expert that can help you with cleaning? And it’s nice to have somebody watching out for that side of the plant.”

And that’s true of hydroblasting as well, Phillips says. “It’s really invaluable to have experienced people who do this, which we do,” he says. “Not only does having experienced people benefit the company, it benefits our clients as well, because they get better products.”
Author: Matt Thompson
Associate Editor, Ethanol Producer Magazine