FROM THE JULY ISSUE: Energy efficiency projects in distillation, dryers and centrifuges are reducing expenses and natural gas usage, but also boosting plants’ capacities.
There’s a drawback to being on the cutting edge of efficiency, leading the way and being willing to experiment with new technologies that aren’t installed anywhere else, says Erik Huschitt, CEO of Badger State Ethanol in Monroe, Wisconsin. “You always have the fear. You always have the risk. You always have the unknown.” Unforeseen problems could “show their ugly heads” at any time, he adds.
Most plants don’t want to be the first to install a new technology, says Scott Lucas, CEO of Lucas E3. “With every new project, there are some things you don’t account for, and there are some problems. But the guys at Badger State, they kind of like the challenge. They’re good at it, and so they’re willing to take on some of these new technologies. These guys are looking to take on new projects and they’re willing to take risk, and that is a big thing in the industry.”
Badger State was the first ethanol plant to install Lucas E3’s dryer exhaust recovery system. It also has a new, more efficient distillation column integration, working hand in hand with an expansion that will bring the 60 MMgy plant up to 90 MMgy.
With an increasing push for overall efficiency in the ethanol industry, Lucas E3 provides evaluation and engineering services for plants. It starts with a detailed model of each plant’s mass and energy balance process flow that illustrates where it could improve—base case versus improved case. Lucas says he can provide engineering services, or plants can take the recommendations and run with them, doing projects on their own. “That model helps not only identify potential projects, but also quantify,” Lucas says. “It’s a pretty good representation of what value they can expect from a particular project.”
Lucas says the main areas where he sees room for improvement are energy efficiency and capacity, many times complementing each other. James Faulconbridge, president of engineering firm Karges-Faulconbridge Inc., agrees, adding that those goals often focus on drying, centrifuge, and distillation and evaporation. “Our clients tend to focus on the triple bottom line of efficiency, capacity and reliability.”
Lucas adds, “I think the biggest opportunity is doing things differently in distillation and evaporation and, of course, grabbing that stack gas.”
Taking on Technologies
When Lucas carries out a distillation project to help a plant become more energy efficient, while increasing capacity, he first adds distillation columns. But it’s the configuration of the columns that helps reduce the amount of steam in the distillation process, he says. “We integrate the columns in such a way that the energy usage goes down per gallon.
“With current systems, you have this cascading energy that allows you to be fairly efficient. So we’re adjusting that slightly to make it even more efficient.” The new distillation columns are run under high pressure, and the energy from that high-pressure system can be integrated into the existing distillation columns. “In essence, we’re adding capacity,” he says. “The steam that’s used to drive the added capacity gets incorporated into the existing plant. So, essentially, we’re adding capacity without adding any more steam usage.”
At Badger State, that distillation improvement alone has already resulted in a 3,000-Btu-per-gallon steam savings, on the way to the targeted 5,000, Lucas says. With both the dryer exhaust recovery system adding recycled steam back into the system, and the distillation improvements, Badger State has seen a 15 percent reduction in natural gas usage. And as of May, the plant was still in the integration phase, tying up all the new components to the existing ones. With the capex invested, the systems installed, the plant already running at a higher capacity, and the inspections passed, it’s on to “secondary things,” Huschitt says. “Now we need to make sure we can sustain those higher rates and sustain those higher efficiencies.”
The basis of the work was an expansion, Huschitt says, that included a hammermill addition, fermentation addition, and an expansion of the carbon dioxide scrubbing capacity, among other components. “Working with Scott, we were able to use our existing infrastructure, making modifications and add capex. … “[We’ve seen] huge increases in efficiencies on our natural gas, but also allowing us to reach the finish line on having a plant that has the throughput capacity we need.”
Most plant boards want to see numbers, Lucas says. They want quantified efficiencies and production increases that make a project worthwhile. “Even though in today’s market, you would think there’s not much room to increase capacity, there’s still a lot of guys out there that are adding gallons. Everybody’s always striving for improvements, continuing to be better every year.” Many plants shoot for a specific number of gallons gained, he says.
Commonwealth Agri-Energy LLC, in Hopkinsville, Kentucky, is expanding by 10 MMgy and realizing a 10 percent natural gas usage reduction, with the help of Lucas’ distillation system improvements. Commonwealth has achieved efficient producer status, and Mick Henderson, general manager, says the company wants to be even more efficient and competitive moving forward. The two-phase project began with efficiency improvements, followed by expansion projects. “There’s absolutely overlap,” Henderson says. But the most important energy efficiency component is the distillation system improvement, he adds. “Our biggest bottleneck was distillation.”
Beyond the distillation system, Commonwealth added fermentation capacity, a second beer well, implemented cooling tower upgrades to use an adjacent quarry efficiently, replaced hammermills and added a sieve bottle. “And instead of adding cooling, we’ll just have more hold time with finished fermentation,” Henderson says. “That’s kind of a neat trick to improve fermentation without necessarily having to add cooling.
“We can’t lose yield,” Henderson emphasizes. “We’d like to maintain that, if not improve that to the next level. We’d like to claim we’re [using] best practices.” All improvements and upgrades were commissioned in July, putting the plant at 45 MMgy. “Scott is a wonderful engineer to work with,” Henderson says. “He and I are likeminded in how we address contractor issues, design issues.”
Commonwealth also replaced its centrifuges, another common energy-efficiency measure Lucas sees at plants. Modification of the centrifuge so it can produce a dry or wet cake means less water has to go into the distillers grains dryers, and that means less gas being burned.
“Reduce energy and you’ve got some dollars you can use to justify a project,” Lucas says.
When KFI performs evaluations for plant efficiency, it includes energy, water balance and benchmarking, Faulconbridge says. Recommendations are specific to each plant, he adds. “Each plant has some unique features and varying utility costs, so the answers tend to be different each time. Even operating choices between plants designed to be similar have an effect.”
Cogeneration and heat recovery are popular, he says. “Most of our work involves a combination of efficiency, maintenance and capacity improvements simultaneously, and touch cook, DD&E, centrifugation and drying.”
KFI often is asked to vet new technologies for ethanol plants, too, to see how or if they will fit operations, Faulconbridge says.
Every plant manager, every general manager is charged with continually finding ways to better the plant, Lucas says. “That’s one of the things I’m able to do for these guys with that plant evaluation. I’m able to give them some good talking points, some good projects that they can go to their boards and say, ‘Guys, here are some things we can do in the next two, three years.’”
It’s easier to assign a concrete dollar worth to energy efficiency projects than it is for operational efficiency projects, Lucas says. It’s hard to quantify the dollar savings of simplified operations manager duties, he adds. “Most people are for energy efficiency because they want to see a dollar amount.”
That’s generally true across the board. For Badger State, the goal was to cost-effectively increase capacity and take advantage of any other energy efficiency opportunities. “We wanted to take the next step and we wanted to see what is the opportunity to really take this plant to its highest limit that we’re aware of with all of the limitations in the original design of the plant,” Huschitt says.
“We know we have to stay on the cutting edge of efficiencies,” he adds. “We know we have to stay disciplined in the fact that we’re in a commodity-based world, and so size does matter. Efficiencies matter. All these things, when we look at our fiduciary responsibility to our investor and to the industry as a whole, we know it’s our obligation to take what we’ve learned, what we’ve experienced, what we’ve experimented with and take it to the next level.”
Huschitt says Badger State is able to consider and implement new efficiency improvements because he and the board have strong confidence in the staff at the plant and their competency in their jobs. The plant has great supervision and leadership, too, but the boots-on-the-ground staff carry the weight of the technology upgrades and experiments. “Make no bones about it, the reason the board or I can have any kind of confidence in taking this kind of approach in being aggressive in finding opportunities and hunting them out is because we have a staff that is, in many cases, 10- to 15-year veterans.”
Huschitt says those veteran employees have the same goals for Badger State that executive leadership and the board of directors do, namely long-term sustainability in the ethanol industry. Reliance on and trust between project partners also is crucial to short- and long-term successes, Huschitt says. It seems there will be more of both for Badger State.
“Either you’re green and growing, or you’re ripe and rotting.”
Author: Lisa Gibson
Managing Editor, Ethanol Producer Magazine
Source: Ethanol Producer Magazine