A Natural Fit

FROM THE MARCH ISSUE: Some ethanol plants are turning to alternative cleaning methods and naturally derived products that are more environmentally friendly than traditional chemicals.
By Matt Thompson | February 20, 2020

While many ethanol plants use caustic soda to clean process equipment, the chemical comes with its fair share of issues. So, Chad Carter, operations manager of Ringneck Energy in Onida, South Dakota, says he’s eager to replace it. “Because the caustic can cause a hinderance to the process, especially with fermentation and the yeast, I’ve always wanted to get rid of it,” he says. But his opinion isn’t common in the industry, he adds. “Since I got in the business, whether I was an operator or production manager, it’s always been caustic. Caustic followed by the acid solution, with whoever’s company you go with.”

In place of caustic, Ringneck uses Ecolab’s products, Trimeta and Trimeta Shield, which Carter says has resulted in a cost savings. He says one order of the chemicals lasts about a month and a half. “When I was using the traditional caustic then followed by an acid solution, I was ordering caustic probably every week,” he says. “So we did a rough cost analysis on that, and we were saving about $10,000 a month just in not buying the caustic.”

And the benefits reach beyond cost savings. “We had an operator error where a ferm CIP valve was left open, and when they were cleaning the other one, some of the acid solution got into our fermentation, and it did not affect it,” Carter says. “The only thing it really did is it just slowed down the kinetics of that ferm a little bit.

“What my job is as operations manager is to try to make this plant as efficient as possible and as safe as possible to run,” Carter says.

Zach Babcock, associate district manager at Ecolab, says the company started working with Ringneck after the plant’s startup last year. “Once they were in a place where they felt comfortable making the change to the standard process, shortly thereafter, we started working with that site to support the cleaning end,” Babcock says.

The process Ringneck is using is similar to the CIP process Badger State Ethanol in Monroe, Wisconsin, is using to remove caustic from its processes, with some minor updates. “Some of the dosing options have evolved and improved since the initial test and partnership with Badger State,” Babcock says. “More diagnostic tools, more integration into the [distributed control system], the base chemistry remains the same and then in 2020, there’s going to be some additional options we can bring to that package.”

And the cleaning process hasn’t had an impact on the plant’s distillers grains. “Everybody now has those [Food Safety Modernization Act] documents they need to supply to the plant,” Carter says. “And we’ve had no ill effects with our DDG or anything like that.”

A Common Theme
Babcock says awareness of the chemicals that are used in the production process has increased. “In the past 12 months, we’ve definitely gotten more requests on whether it’s a cleaner process, more awareness of what’s going into their process, and/or removal of certain items from the process,” he says.

The reasons for looking more critically at the chemical inputs vary among plants, Babcock says. “Some plants have more challenges from a lactic and acid perspective and have more challenges with infection than others. Those customers may really be looking to help clean up their process. Or a site may be looking to remove other things from their process such as limiting the amount of sulfuric acid they need to pH adjust their process.” He adds that some plants are simply looking for cost reduction, while others want healthier yeast and fermentation.

Stacey Campbell, ethanol technical services manager for BetaTec Hop Products, says FSMA has made producers more conscious about what goes into their distillers grains and coproducts. “I feel like definitely plants are thinking along those lines and looking down the road for the future,” she says, adding that the trend is also customer-driven. “I feel that is a trend that I do see more,” Campbell says. “I’ve been in the industry for a while, but it seems that probably within the past three to five years, it’s a more up-front topic versus what it was 10 years ago.”

Microbial Control
For plants looking to remove antibiotics, or cut down on their use, BetaTec supplies a natural hop product that can be used for microbial control.

“We’ve discovered a way we can extract and isolate those natural compounds and that’s where we’ve provided a liquid extract that can provide bacteriostatic activity,” Campbell says. A major advantage of using a naturally derived product, Campbell says, is that bacteria don’t develop a resistance to it.
Campbell says the hops contain natural, weak organic acids. When those organic acids are dosed to the propagator, “any of the bacteria that’s present will absorb the hop extract through the cell wall and with this being a weak organic acid, it will reduce the pH within the bacterial cell,” Campbell says. That reduction prevents the bacteria from absorbing glucose. “It’s going to essentially starve the bacterial cell of its food and prevent competition with the yeast for the glucose.”

In addition, the natural process can have a positive impact on fermentation. “We typically see improved health with increased cell counts that may translate into an increase in yield of your ethanol,” Campbell says.

Rick Bradley, production supervisor at Golden Triangle Energy in Craig, Missouri, says his plant has seen those benefits. “It seems like it makes your yeast healthier and it increased our yield a little bit. Those are good things.”

Golden Triangle began using BetaTec’s antimicrobial solutions both as a cost saving measure, and with an eye toward becoming antibiotic-free, Bradley says. The plant has been using BetaTec’s IsoStab for more than 15 years. “We don’t dose a whole lot, so it makes our cost low,” Bradley says. “We knew that they were pushing and talking about these antibiotic-free feedstuff, so we were looking at ways to meet that and we were already using a product that we knew we could get by with and say we’re antibiotic-free, and control our lactics and acidics and bacterial infections in fermentation.”

Babcock says Ecolab also has customers exploring antibiotic-free options. “We’ve had a couple sites tell us that’s really where they’d like to be in the next 12-plus months, and it’s something that I truly believe the industry can get to,” he says. While Ecolab isn’t an antibiotic supplier, he says the company strives to help plants achieve their goals by helping to manage the CIP process. “I think it’ll take time, but just based on what can be done in other industries—the dairy industry and the broader global brewing industry—I definitely believe with the correct targeted changes in the process, there’s no reason a biofuels plant can’t run antibiotic-free at some point.”

Meanwhile, EcoLab is helping plants clean up their cleaning processes. At Ringneck, Carter says the switch to chemicals that are less harsh and more environmentally friendly has resulted in a good regimen. “I’ve spent most of my time these first several months dialing everything in, getting everything optimized and then optimizing the chemical as well,” he says. “Basically, we’re at where we want to be for that cleaning process.”

Author: Matt Thompson
Associate Editor, Ethanol Produce Magazine