Power outage sparks fire at the Green Plains Wood River, NE ethanol plant
Thursday, July 7, 2016 2:41 pm | Updated: 3:33 pm, Thu Jul 7, 2016.
By Kelli Rollin
kelli.rollin@theindependent.com
WOOD RIVER, NEBRASKA— A power outage caused a fire at the Green Plains ethanol plant in Wood River, NE Thursday morning.
Todd King, Wood River fire chief, said his crew was called around 5:40 a.m. to put out the fire. He said the fire was contained in the dryer, but the crew had to be there when the hatches were opened to put out the fire.
"Once we left, it rekindled in the upper leg," King said.
He said the crew was called back about 15 minutes after they left the first time.
"It did considerable damage to their dryer," King said about the fire and the ethanol plant.
King said no one was hurt in the fire.
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Ethanol
Ethanol is a chemical produced by the fermentation of sugars found in grains and other biomass.
Ethanol can be produced from a number of different types of grains, such as corn, wheat and sorghum, as well as from agricultural waste products such as rice hulls, cheese whey, potato waste, brewery and beverage wastes and forestry and paper wastes. At present, the majority of ethanol in the U.S. is produced from corn because corn contains large quantities of carbohydrates and is in greater supply than other grains. Such carbohydrates convert into glucose more easily than most other kinds of biomass.
Green Plains was formed in June 2004 to construct and operate dry mill, fuel-grade ethanol production plants. Ethanol is a renewable, environmentally clean fuel source that is produced at numerous facilities in the United States, mostly in the Midwest. In the U.S., ethanol is produced primarily from corn and then blended with unleaded gasoline in varying percentages. The ethanol industry in the U.S. has grown significantly over the last few years as its use reduces harmful auto emissions, enhances octane ratings of the gasoline with which it is blended, offers consumers a cost-effective choice, and decreases the amount of crude oil the U.S. needs to import from foreign sources. Ethanol is most commonly sold as E10, the 10 percent blend of ethanol for use in all American automobiles. Increasingly, ethanol is also available as E85, a higher percentage ethanol blend for use in flexible fuel vehicles.
Operations commenced at our first ethanol plant, located in Shenandoah, Iowa, in late August 2007; the next ethanol plant, located in Superior, Iowa, commenced operations in July 2008; the third ethanol plant to come online is located in Bluffton, IN, and began producing ethanol in September 2008; our next ethanol plant to begin production is located in Obion, Tenn. and had its first grind in November 2008. On July 2, 2009, we acquired two ethanol plants located in Nebraska. The plants are located in Central City and Ord and add 150 million gallons of ethanol production capacity per year. On October 22, 2010, we acquired two plants located in Riga, Mich. and Lakota, Iowa and on March 24, 2011 acquired a plant in Fergus Falls, Minnesota. We acquired our tenth plant in Atkinson, Neb. in June of 2013. In November 2013 we acquired plants in Wood River, Neb. and Fairmont, Minnesota. In October 2015, we acquired a plant in Hopewell, Virgina and in November 2015, we acquired an ethanol plant in Hereford, Texas. At capacity, our 14 ethanol plants produce a total of approximately 1.2 billion gallons of fuel-grade ethanol annually, making Green Plains the fourth largest ethanol producer in North America.
Green Plains is a vertically integrated ethanol producer based in Omaha, Nebraska. We currently have an ethanol production capacity of approximately 1.2 billion gallons per year with our 14 plants strategically located across the U.S. We also operate an independent third party ethanol marketing business, Green Plains Trade.
Distillers grains are an important co-product of Green Plains’ ethanol production. At capacity our plants will produce approximately 3.4 million tons of distillers grains annually that will be used as a high-protein, high-energy animal fodder and feed supplement. Corn oil is also a co-product of ethanol production that is being extracted at 13 of our plants. Corn oil is sold to biodiesel manufacturers and to feed lot and poultry markets.
Green Plains also provides grain storage through our Subsidiary – Green Plains Grain. Green Plains Grain has grain storage capacity of approximately 56 million bushels, including on-site storage at our ethanol plants, that are used to support our grain merchandising activities, as well as our ethanol plant operations. We believe that incorporating this business segment into our operations increases efficiencies and reduces commodity price and supply risks.
Looking to next generation technology, Green Plains is part of a joint venture called BioProcess Algae to commercialize algae production technology. In addition to Green Plains, the other partners in the venture are CLARCOR Inc. and BioProcess H2O. The project, located at Green Plains in Shenandoah, Iowa, received a grant from the Iowa Office of Energy Independence totaling $4.1 million.
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Protecting Ethanol Plants from Catastrophic Combustible Dust Explosions
Industrial vacuums help prevent secondary explosions
By Doan Pendleton | June 12, 2012
Fugitive dust and dust explosions have been a hot topic since the early 20th century as evidenced by the 1922 publishing of National Fire Protection Association’s “Dust Explosions.” The authors, David J. Price and Harold H. Brown, acknowledge the need for a vacuum that could withstand the rigors of an industrial environment recognizing that, despite every precaution to capture dust at the source, small amounts of it “will get out into the atmosphere of the mill and gather on floors, walls and ledges.”
The authors knew then, as it still stands today, “if there is no accumulation of dust and the plant is perfectly clean, the explosion cannot propagate and the plant will not be destroyed.”
Primary dust explosions occur when combustible dust is present, forms a dust cloud (in sufficient amounts), in an enclosed environment, with an ignition source and oxygen.
Bill Stevenson, vice president of engineering at Cv Technology Inc. and NFPA 654 committee member, says, “the explosion is caused by the rapid pressure rise as a result of the rapid burning of the dust cloud. So it has to be in an enclosure. If it were outside you’d just have a big flash.” Cv Technology is a Florida-based corporation dedicated to the prevention, protection and mitigation of industrial dust explosions and related fires.
Stevenson further explains that if there were a layer of combustible dust on a desk, “you could get it to burn by putting a flame to it, but it wouldn’t explode. If you took the torch away, it would smolder and most would self-extinguish; but, if you take the same dust, throw it in the air and then light it on fire, it would literally blow up in your face,” he says.
Catastrophic secondary explosions occur when the force from the primary explosion dislodges fugitive dust, producing more dust clouds, and creating a domino type effect that can cause further explosions. So if you took that same dust smoldering on the desk and waved a piece of paper to make the particles airborne, a dust cloud could form and explode.
According to “U.S. Industrial and Manufacturing Property Structure Fires,” an NFPA fact sheet, “ fire departments responded to an estimated average of 10,500 structure fires in industrial and manufacturing properties per year in 2003-2006,” averaging 29 fires per day in the industrial sector.
Controlling the Explosion Pentagon
The explosion pentagon includes the three elements of the fire triangle, fuel (combustible dust), ignition source (heat) and an oxidizer (air), but needs two additional elements, dispersion of dust particles in sufficient quantity and concentration and the confinement of the dust cloud in a vessel or building.
If one of the elements is missing, an explosion cannot occur. Although every precaution is taken to eliminate ignition sources to prevent fires, and dust collection equipment designed to safely contain most of the dust in the plant is present, producers must make housekeeping for fugitive dust equally important. Fugitive dust can potentially become a dust cloud that fuels an explosion.
Industrial vacuum cleaners to control fugitive combustible dust should be suitable for use in Class II Div 2 areas—generally areas where accumulations of combustible dust are present such as milling, drying and screening areas, as well as in and around conveyors and where spillage occurs. “Vacuum cleaners in particular are vulnerable to ignition and that is why there are only a few companies that do it right,” says Stevenson. “They take extraordinary care to make sure there is no chance for the product to come into contact with anything ignitable.”
Vac-u-Max, a pioneer in industrial vacuum cleaning and pneumatic conveying since 1954, makes a line of combustible dust vacuums that are redundantly grounded. Any time there is powder flowing in one direction through a plastic vacuum-cleaning hose it can create a significant static electric charge. In addition, there is the possibility that there may be static electricity build-up on individual dust particles. If a charged, ungrounded hose used to vacuum combustible dust powder were to contact an object that was grounded, the static electricity could arc and trigger a violent explosion. This is why the Occupationational Safety and Health Administration has issued numerous citations for using standard vacuum cleaners where Class II Div 2 equipment is required.
The Right Tool for Combustible Dust
Bill Bobbitt of Bobit Associates Environmental Systems, who’s been working in the clean air industry for over 25 years, says, “I always tell my clients, it is not a matter of if, but when. Conditions have to be perfect and that ‘when’ can be 30 years from now, or it could be next week. But if you eliminate the fugitive dust, it cannot create a secondary dust explosion,” he says.
Employing an industrial vacuum cleaner that is redundantly grounded in five different ways, “eliminates the possibility of any kind of explosion from the vacuum,” says Bobbitt. Although Vac-u-Max does make electric vacuums designed for Class II Div 2 environments, the most economical solution for cleaning combustible fugitive dust is its air-operated vacuums.
Beyond the fact that air operated vacuums use no electricity and have no moving parts, the first of the five ways that Vac-u-Max vacuums are grounded begins with the air line that supplies the compressed air to the units. Because most plants have compressed air lines made from iron that conducts electricity, the company’s air operated vacuums use static- conductive, high-pressure compressed air lines. In addition, static conductive hoses, filters and casters are employed to further reduce risk. A grounding lug and strap that travels from the vacuum head down to the 55-gallon drum, eliminates the potential for arcing.
Unclear Regulations
Fugitive dust “is a moving target that changes depending on the nature of the process and how well plants manage keeping the dust contained,” says Stevenson. Most NFPA guidelines for combustible dust state that a layer of dust the thickness of a paperclip is enough to cause a significant secondary explosion. The problem, he says, “is that it doesn’t account for the different Kst values between different dusts. [Kst is used to classify dusts according to their explosivity—the rate of pressure rise of a dust in the test vessel upon being ignited.] Some are more reactive than others. Some are more easily suspended into a cloud. Some tests found that depending on the type of dust, even half of the thickness of a paper clip would be too much.”
In situations where many different dusts are handled, testing all of them can be prohibitively expensive. For instance, in a high- performance rubber plant where several different products are manufactured within the same plant, the dust in each area of the plant may have different Kst values in each area. For this circumstance, it is recommended to work with an expert in the field to select samples for test that represent the worst case.
This is why, Bobbitt says, that when you are dealing with explosive dust, you may need a Class II Div 2 vacuum in a non-Class II Div 2 area. “You might have explosive dust small quantities, and it might take a very hot and prolonged source of ignition, but with the new combustible dust initiative, facilities need to be very careful that they comply because there is a lot of question as to what compliance means.”
“Although the regulations for combustible dust aren’t real clear,” Bobbitt adds, “I find that a lot of companies are simply just trying to get better at general housecleaning.” Cv Technology’s Stevenson agrees. “The one thing you can do very simply and easily is to keep everything clean—it is as simple as that. If you clean the place up and protect your dust collectors, you’ve gone a long way toward minimizing the chance for an explosion even if you do nothing else; and those are pretty straightforward, easy things that everyone can do,” he says.