Facility Feature
Golden Grain Energy, LLC Adds World's Largest Steel Grain Tank

Mason City, IA — The sign mounted on the side of the new Sukup 2.2-million-bushel corrugated steel tank at the Golden Grain Energy, LLC ethanol plant in Mason City, IA says it all: WORLD’S LARGEST GRAIN BIN 2021.

The $10 million-plus project, which Grain Journal visited in late April 2021, was on track to receive corn by June 1, with only some electrical work to be completed.

Realistically, though, the tank wasn’t likely to be filled before September, says Golden Grain CEO Chad Kuhlers, who has been with the company since the plant first opened in 2003. “With the current inverse in the market, we don’t expect farmers to be moving grain here immediately,” he says.

The decision to add the “Binzilla” tank was made following a grain origination study Golden Grain completed early in 2020.

“We had a corn storage supply for nine to 10 days of ethanol production,” says Kuhlers, “and we projected a need to increase that to 30 days. We also needed more unloading capability to make us the destination of choice for farmers.”

The decision on the 2.2-million-bushel tank came after Sukup Mfg. Co., Sheffield, IA (641-892-4222), made an offer to design one. “(Sukup President and CEO) Steve Sukup is on our board of directors, and he offered to make a tank bigger than anyone else’s,” Kuhlers reports.

Sukup Mfg. is no stranger to the world of big grain tanks. The company already has built three 2-million-bushel tanks, all of them in Iowa. At 165 feet, the new 2.2-million addition is 9 feet in diameter larger and 44 inches taller (one ring) in eave height than the 2-million tanks.

Groundbreaking on the new Golden Grain tank took place in September 2020.

Golden Grain Background

Installing such a huge tank was the inevitable outcome of a series of expansions at Golden Grain over the past 18 years.

Golden Grain was started by a group of farmer-investors from northeast Iowa, who raised $28 million for a 40-million-gallon-per-year (gpy) plant. They selected Mason City due to its proximity to a large supply of corn, a site on the Union Pacific Railroad, and two four-lane highways nearby (Interstate 35 and U.S. Highway 18).

The company expanded its production capacity at Mason City several times since it opened, most recently to its current level of 125 to 130 million gpy. That level of production prompted the grain origination study, which led to the construction of the new tank.

To build the new tank and adjacent enclosed receiving building, Golden Grain hired McGough Construction Co. Inc., St. Paul, MN (651-633-5050), as the overall project manager. McGough is primarily an industrial and commercial contractor but has extensive experience in the ag industry. They brought in Buresh Building Systems Inc., Hampton, IA (641-456-5242), as the millwright and Global Bin Builders, Iowa Falls, IA (320-413-0312), for bin erection.

Tank Design Sets Up For 2.2 Million Bushels

In the meantime, as Sukup set out to design a 2.2-million-bushel tank, a number of factors went into the design:

To stand up to the internal pressure generated by that much grain, the sidewalls required multiple laminations most of the way up the eave height of the tank.

Instead of more conventional overlapping sidewall panels, Sukup utilized its patented laminated splice plates at the vertical seams. Sukup also used its patented double-ended stud bolts between the laminated sidewall panels and the stiffeners. This fastener has two threaded ends, a rubber-backed sealing washer, and a hex feature in the center of the threaded ends. This prevents water from seeping between the stiffener and the sidewall and infiltrating into the grain.

Engineers also beefed up the roof structure of the 2.2-million-bushel tank to handle up to a 150,000-pound load for fill equipment based on a 40-psf ground snow zone.

To support the weight of the 125-million-pound fully-loaded tank, Buresh used engineered fill material to be placed underneath the tank. This holds settlement of the tank to less than an inch, unlike more conventional packed dirt or gravel.

Project Specifications Feature Sukup, AGI Hi Roller

The completed tank stands 165 feet in diameter, 110 feet tall at the eave, and 156 feet 7 inches tall at the peak, towering over the rest of the facility.

It is equipped with outside stiffeners, a Sukup 10,000-bph zero-entry paddle sweep, 49-cable AGI CMC grain temperature monitoring system, and Ronan nuclear level indicators. A set of 10 Sukup 50-hp centrifugal fans provide 1/10 cfm per bushel of aeration with 22 2-hp roof exhausters.

Adjacent to the tank, a Sukup enclosed steel building houses a 1,800-bushel mechanical receiving pit. The pit is serviced by a Donaldson Torit baghouse dust collection system.

The pit feeds grain to a Sukup 25,000-bph leg running up the east side of the tank. The leg is equipped with two rows of Maxi-Lift 22x8 CC-HD buckets mounted on a 48-inch belt.

The leg is enclosed in a 20-foot-x-20-foot-x-195-foot Sukup support tower with a switchback staircase. The leg deposits corn onto an AGI Hi Roller Hi Life 50,000-bph enclosed belt conveyor running out to the tank.

The tank empties onto an above-ground Sukup 10,000-bph drag conveyor, which in turn deposits grain onto a series of Sukup 10,000-bph drag conveyors running into the ethanol plant.

Ed Zdrojewski, editor

-From May/June 2021 Grain Journal

Golden Grain Energy LLC Mason City, IA • 641-423-8525

• Founded: 2002
• Annual ethanol production: 120 million gallons
• Number of member-owners: 900+
• Number of employees: 50+
• Products: Fuel-grade ethanol, food-grade corn oil, distillers’ grains

Key personnel:

• Chad Kuhlers, CEO
• Scott Dutka, plant manager
• Brooke Peters, CFO
• Scott Gudbaur, commodity manager

Mason City Supplier List

• Aeration fans • Sukup Mfg. Co.
• Bearing sensors • 4B Components Ltd.
• Bin erection • Global Bin Builders
• Bin sweeps • Sukup Mfg. Co.
• Bucket elevator • Sukup Mfg. Co.
• Concrete • Yohn Co.
• Control system • Trident Automation
• Conveyors (belt) • AGI Hi Roller
• Conveyors (drag) • Sukup Mfg. Co.
• Dust collection • Donaldson Torit
• Electrical contractor • Interstates
• Elevator buckets • Maxi-Lift Inc
• Engineering • KFI Engineers
• Excavation • Popp Excavating Inc.
• General contractor • McGough Construction Co. Inc.
• Grain temperature system • AGI CMC
• Level indicators • Ronan Engineering Co.
• Millwright • Buresh Building Systems, Inc.
• Motion sensors • 4B Components Ltd.
• Motors • Toshiba International
• Speed reducers • Dodge
• Steel building • Sukup Mfg. Co.
• Steel storage • Sukup Mfg. Co.
• Tower support system • Sukup Mfg. Co.