Process checkups

FROM THE JULY ISSUE: Having captured the low-hanging fruit, debottlenecking and plant optimizations begin a second round.
By Susanne Retka Schill | June 16, 2017

The ethanol plants built in the boom of the 2000s were well-designed, process engineers will tell you. In the decade since, operators have found ways to fine tune and upgrade those original designs. The first round of those ethanol plant optimizations is coming to a close and a second round has begun.

In the first round, most plant managers tapped into built-in surplus capacity—the engineering over-design done to ensure plants met their production guarantees at startup. Since then, multiple small upgrades have been applied, many of which were trial-and-error tweaks. “They’ll increase the grind ever so slightly, then see where the equipment can’t handle more capacity,” says Rob Hormell, associate process engineer at Burns and McDonnell. “Early on there was an issue when you increased capacity; you couldn’t get the fermenters filled fast enough, so a lot of plants put in booster pumps.”

“A lot of it is around good management—good practices in the plant on the operations side and mechanical side that improve plant uptime and reliability,” says Neal Jakel, vice president of strategy and technology at Fluid Quip Process Technologies. Some of the low-hanging fruit widely adopted by plants, he says, include improving heat exchanger recovery and clean-in-place practices to prevent infections and lost yields, along with better controls. “Things like running the process in a more steady state and running with higher uptime,” Jakel says. “Those are big improvements to the bottom line, in addition to getting more throughput and increased yields.”

Greg Loest, principal with Integro Energy, says the first optimizations to be chased were around energy and heat recoveries, chemical optimizations and control schemes, not to forget fermentation itself. “When you are consistent within the slurry tank and you have very low variability in regards to solids, temperatures and enzyme additions on the front end, magically the back end of the facility runs extremely smooth,” he says. “That seems very straightforward and sounds like a simple process, but it’s not. When you get into the plant and you have 1 percent variability on dry solids, that puts a wave on how much alcohol you make, and a wave into distillation and into the dryers—into the whole plant. I’m talking about getting control points down to less than a tenth in variability on the front of the facility.”

Debottlenecking Strategies
Each of the process engineers cite multiple small and large projects that brought plant improvements in the first round of industry optimizations that is ongoing today. Some estimate as high as 40 percent of plants have first-round optimizations that can be made, even as the industry moves into the second round of more capital intensive upgrades.

“What we’re finding is that these plant operators have tweaked and hot rodded their plants. They’re running them flat out and doing a great job,” says George Baskin, director of innovation projects at Burns and McDonnell. The obvious improvements have been made at many plants, he says. But now process engineers are turning to more advanced tools to continue debottlenecking. And, vendors are offering innovative technologies as the next round of improvements. While the equipment providers are the experts on their equipment, Baskin says, the process engineers help with successful plant integration.

“We realize we can’t do much more to these plants without spending large amounts of capital,” Hormell adds. “The engineering solution is to analyze the equipment, identify improvement opportunities and target projects. We analyze equipment in unit operations—distillation, cook, evaporation, that type of thing. If evaporation is the limiting factor we identify, then we can talk about ideas to remedy that issue.”

FQPT has a master list of more than 70 process improvement projects—debottlenecking projects for every part of the plant, Jakel says. “We provide a service where we go through the entire plant from the front to the back end and we look for the pinch points. A lot of times, we have simple projects to eliminate those pinch points, because we’ve dealt with them in other plants. Other times, we may find a new one and we’ll engineer a solution.” He recommends developing a mass and energy balance for all systems in a plant to establish how the plant is running. “That allows us to model potential future production rates and identify future bottlenecks that we can address today. It basically positions the plant to incrementally start producing more gallons going forward.”

That sort of comprehensive planning goes a long way toward keeping capital costs down, Jakel says. A project to add 30 MMgy in one fell swoop can cost $1.50 to $2 per gallon. A more systematic approach identifying pinch points, examining mass and energy balance scenarios and implementing strategic improvements planned around scheduled maintenance downtimes can bring that cost down to 10 or 15 cents per gallon, although it may take two or three years to accomplish a capacity expansion. “It’s a capital deployment plan that ties into the plant debottlenecking plan,” Jakel says.

As Loest describes going back and forth with a plant considering a capital project, it begins to sound like a process engineer acts as a plant counselor. “We reviewed what they wanted to do, and started asking very specific questions about other areas of the facility that hadn’t been addressed. Their idea wasn’t going to get them the bang for the buck they anticipated. They need to address a number of other areas that will make them more efficient and give them the flexibility so they can come back and do the project they want to do.”

In the first round of process improvements, Loest says, “Everybody was fresh out of the gate. A lot of technologies that went into the plant were very straightforward, off-the-shelf, plug-and-play. As the plants have gotten further along and matured in how they operate their facilities and how their markets function, everything is becoming more custom.” Different plants have different bottlenecks, different capacity constraints, different mentalities, he says. “So while the core idea might fit, it still has to be tweaked every single time independently.”
   
Beyond Capacity
Just adding gallons is not the answer to future viability, the process engineers stress. While there are some economies of scale that benefit bigger companies, the cost of corn and sale price of ethanol and coproducts are the same for all. Small producers can remain in the game, if they keep up and strive to be low-cost producers.

Jakel points to the maxim that if you’re not growing, you’re dying. “So how am I growing the business? There’s organic growth, which is growth within—constant growth in production, in cost reduction, in efficiency and yield improvement, energy utilization. All those things continually help the bottom line. It makes a plant more cost-competitive in tight-margin environments.”

Regardless of size, plant operators with a systematic approach to constant improvement, who are putting money in the right areas, are thriving, he says. “We’ve worked the gamut from small 30 MMgy plants with single owners to 100 MMgy big, corporate run with multiple plants. Multiple technologies, single technologies—we’ve seen it across the board. Honestly, it’s the well-disciplined, well-managed plants, the operations teams who have the technical skills, or know that they need to bring in the technical skills via third party, to optimize the plants. Those plants are the winners for yield and uptime.”

Ethanol yield is one metric plants follow closely. The Minnesota-based accounting firm Christianson PLLP collects production and economic data from between 60 and 75 plants participating in its benchmarking program in the past five years. Plants compare metrics to see whether they are average, or land among the leaders or laggards. When it comes to ethanol yield—the gallons of ethanol produced per bushel of corn—the difference between the top and the bottom is significant. The difference of 0.16 gallons per bushel between the leaders and laggards in the 2016 benchmarking program would amount to roughly $2.5 million more in the bottom line for a 100 MMgy plant getting $1.50 per gallon for its ethanol. Connie Lindstrom, biofuels analyst for Christianson, says the plants participating in the benchmarking program are representative of the industry, comprised of large and small producers, as well as single and corporate ownership structures. “What we notice is that the laggards in ethanol yield tend to be the plants that have increased capacity,” she says.

Loest is not surprised. “There’s constant relearning,” he says. Every change in the plant creates a wave that affects every other part of the plant. He firmly believes that in the next round of process improvements, plants must do a better job of utilizing data on a daily and monthly basis. “[They need to] dive deep into the data historian and cross tie that over to the lab to find those little tweaks on efficiency improvement in temperatures and pressures front to back, proper dosing schemes and proper density and water-balance control, and things of that nature.”

Loest suggests cost per gallon is a more important metric to track than yield. “Don’t tell me how many gallons you make, tell me what your cost per gallon is, or cost per bushel—that tells me how efficient you are.” There are plants netting 40 cents per gallon that have been innovators trying to set themselves up for the long run, he says, “versus plants that have hung onto their cash and don’t spend money to improve that are making 10 to 15 cents per gallon net. That’s a big spread.” He cautions that as the industry continues to expand production beyond the blend wall, finding markets for the additional ethanol and distillers grains becomes ever more critical and it is inevitable a margin squeeze is going to come.  “Now is the time the plants need to be focusing on efficiency. They can’t just be focusing on gallons. They have to be efficient at what they’re doing.”  

Jakel agrees, “Plant efficiency improvements are the backbone of any good business.” Rather than adding sheer gallonage, he advocates the industry move toward product diversification. “Revenue growth through product diversification is key to shareholder return and long-term profitability,” he says.


Author: Susanne Retka Schill
Managing Editor, Ethanol Producer Magazine
701-738-4922
sretkaschill@bbiinternational.com