Perfectly Planned

FROM THE NOVEMBER ISSUE: With proper planning, expansions can go relatively smoothly. Without it, large, unforeseen obstacles can increase costs, delay startups and derail projects.
By Lisa Gibson | October 17, 2018

Ryan Brock, technical services manager for Lallemand Biofuels & Distilled Spirits, has horror stories about poorly planned ethanol plant expansions: a plant that forgot to notify the gas supplier of its expansion and was shut down when the supplier assumed the massive increase in use was the result of a leak; a plant that had doubled its capacity but was forced to delay startup because it realized too late that its current server couldn’t handle the expanded programming in the distributed control system; a plant that blew a transformer because the power company wasn’t aware of the expansion or prepared to supply it.

Brock doesn’t directly handle expansions, but his job puts him in plants planning or having recently completed them. In fact, he’s so seasoned on the topic, he delivered a presentation on it at the 2018 International Fuel Ethanol Workshop & Expo. “You see what happens,” he says. “They’re more than happy to not spread their agony to the rest of the industry.” The biggest problems, he says, are results of incomplete planning and failure to analyze the expansion effects on each area of a plant. “Once you’ve decided you’re doing an expansion, not just debottlenecking your plant, spend a lot of time actually mapping out what you’re going to do so you don’t have to go back and redo something or fix some other problem you caused.”

Understand the Problem
If debottlenecking comes hand in hand with an expansion, it’s important to fully comprehend the issue and plan for increased efficiency, Brock says. “If you know you have a bottleneck in distillation, make that new distillation a little bit more efficient in your design so that you can take some of the pressure load off of your already-struggling area. Make sure you understand the problem that you already have, so you don’t just make that problem worse when you expand.”

One plant manager explained to Brock that the plant added two ferm headers, but had had an issue in one of the existing ferm headers. After the expansion, the plant had infections in six fermenters instead of four. “Find the issues you already have before making them worse down the road,” Brock says. 

Keep an eye on the areas of the plant that aren’t being expanded, too, he says. “You’re not touching this part of the plant, but you need to remember it’s impacted.” For example, if distillation is doubled, that means twice as much material is being handled in whole and thin stillage tanks. “You forget about those two tanks, but now you’re putting twice as much into them, twice as fast.” If cook goes down, overflow occurs in half the time. “You’re shooting mash out of the ceiling.”

Al-Corn Clean Fuel in Claremont, Minnesota, didn’t make that mistake when planning its 70 MMgy expansion, says CEO Randall Doyal. “This issue is something we addressed very early on in our design, and I am happy to say that it hasn’t been an issue,” he says. “Instead, because of the things we changed or repurposed, we found additional capacity in the old plant.”

Al-Corn determined in 2015 that it would move forward with an expansion from its 50 MMgy to 120 MMgy, calling it a “modernization and expansion,” Doyal says. The plan, in partnership with Karges-Faulconbridge Inc. and McGough Construction, was to update some parts of the existing facility, continuing to use existing distillation, evaporation and drying. New build projects included grain receiving, milling, distillers dried grains with solubles cooling and storage, and a cook system. “We also built a new distillation, evaporation, molecular sieves, dryer and RTO sized to provide the additional 70 MMgy of capacity,” Doyal says. “In addition, we repurposed some of our existing tankage to provide upsized liquefaction, cook water and cleaning process storage.”

While planning for the entire facility was a success, Al-Corn did hit snags in other areas. “Permitting in our state is a tremendous time drain,” Doyal says. “It takes far too long. The time delay caused project costs to increase, and we had to become very creative in redesigning, or what KFI and McGough call ‘value engineering.’” He says the project was able to come in at the original budget, but it wasn’t easy. “We were also dealt some unexpected blows with the programming of our control system. This caused us serious problems with our startup efforts and drug out the time required to get the plant up to rates.”

Modeling Software
Planning for those potential issues down the line can be easier with the help of Aspen modeling. Tiffany Trottman, business development manager for Nelson Engineering, says use of the software is common in chemical engineering designs, but fairly new to the ethanol industry.

An Aspen model can be as detailed as necessary, down to the piping and hydraulics of a plant. But it starts with a focus on the main equipment, Trottman says. “When we build an Aspen model for an ethanol customer, a lot of times we’re going to start by focusing on the major process equipment.”
Aspen can help scientifically verify the capacity of existing equipment and pinpoint issues, she says. “Maybe internals in a distillation column are causing problems. Now you can be more focused and precise in your expansion efforts to understand what is truly needed and why.” That includes power consumption, a caution Brock lists. “Understand power consumption currently and after expansion,” Trottman says. “It’s a significant lead time to get a substation up to requirements for new demand.”
Aspen also can help map how a bolt-on technology will integrate into an existing plant, she says, and verify third-party claims about carbon intensity scores.

“Aspen gives you the ability to take an incredible amount of information—you have an entire processing facility and you have 40-some people who are staffing this day-to-day operation—and it’s helping you condense it into a snapshot,” Trottman says. “That allows you to make educated decisions all in one spot, from the capital side of it.” 

Building an Aspen model can take eight to 12 weeks, depending on the specific plant and details.
Brock refers to the Aspen model as an example of how plants can make sure they plan for increased demands in an expanded facility. “You’re going to adjust your entire stream through your plant, so you have to understand where other adjustments will need to be made.”

‘Chasing Rabbits’
Following Al-Corn’s successful expansion, Doyal says it’s crucial to properly and thoroughly consider plans and goals. “Think about your existing facility, your site and your potential future growth. Spend plenty of whiteboard time shooting down ideas and chasing rabbits until a plan starts to solidify.”

Al-Corn, KFI and McGough Construction were the recipients of Ethanol Producer Magazine’s 2018 Collaboration of the Year Award. “The reason collaboration is important is because you are never as smart as you think you are,” Doyal told Ethanol Producer Magazine when the award winners were announced in May. “You can fall in love with your own ideas but still be completely wrong.”

Don’t be afraid to challenge decisions and rethink options at any stage of the game, he says. “Ideas on paper cost far less than steel and concrete to modify.”

Author: Lisa Gibson
Editor, Ethanol Producer Magazine