Manure Manager

Features Applications Poultry
A new take on digesters


March 7, 2008
By Diane Mettler

Topics

Brinson Farms designs a digester that can process broiler litter – and that’s just the start.
Brinson Farms designs a digester that can process broiler litter – and that’s just the start.

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The quality of gas generated at the Logan poultry farm is high, registering at 70 percent methane. It was originally predicted that gas generated by the digester would only be in about the 50 percent methane range.

Photo By Greg Gibson, Mississippi Farm Bureau Federation.

John Logan says he retired 14 years ago. That is when he and his wife Bettye moved back to her family farm to get away from the rat race and “to relax and do some farming.” But Logan’s version of retirement begs the question – if this is relaxing, what was he doing before?
The 1000 acre farm, located in Prentiss, Mississippi, had sat idle for 26 years. It had seen its share of hurricanes and tornados and was in a state of disrepair.

John got busy putting the farm back in shape, although his background wasn’t in farming. “I taught eight years of college, and have about 20-plus years working with large corporations and in the computer industry. I also have 38 years with the National Guard.” But amazingly that experience would soon serve him well.

A New Poultry Farmer

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The solar panel system on John Logan’s farm is used to help power water pumping through out his farm. It also heats the water required by the operation’s 250,000 gallon manure digester.

Photo By Greg Gibson, Mississippi Farm Bureau Federation.

Logan decided to make the farm a poultry operation based on a consulting job he had in the early 1970s. “It was for a major poultry integrator in Mississippi. The owner wanted me to know the poultry business before I started doing any employee training or computer programming. He taught me the ins and outs of the industry and I always found it fascinating.”

Logan built five broiler houses, which he has now expanded to 10. They hold approximately 275,000 chickens and produce around 1500 tons of litter a year. And initially they used the fertilizer on the fields to get the soil back in shape.

As they revived the farm, they made sure it met all the environmental requirements. “If you’re starting from scratch, you can do it right,” John says. “We designed it with the proper environmental impact, for buffer zones and watershed and erosion control, conservation and wildlife.” And that has earned them the Tyson’s National Environmental Stewardship award twice.

Deciding to Cut Energy Costs
After being in operation about eight years, Logan realized there were two things out of his control – the birds (as he is a contract grower) and utility costs. He was using a tremendous amount of propane to heat the houses as well as electricity to cool them in the summer. He began looking for alternatives.

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The Logan’s 1000 acre poultry operation – located in Prentiss, Mississippi – has been slowly rebuilt and revitalized over the past 14 years. The operation had sat idle for 26 years before John and Bettye moved in.

Photo By Greg Gibson, Mississippi Farm Bureau Federation.

First he created a propane company and marketed propane wholesale to himself and many Mississippi farmers. “I got active in the industry and learned about its energy needs,” John says. “Now I’m the U.S. advisor on the American Farm Bureau of Poultry, as well as the State of Mississippi.”

But that was not enough. “I knew you could take manure and generate a sizable amount of methane,” he adds. “The only problem was I had chicken litter, which has no natural methagans, like in dairy and swine.” Also his litter was mixed with wood shavings for bedding.
As it turned out, Tyson decided to stop giving its chickens antibiotics and wanted Logan to start bedding the chickens on manure. “What happened was there were no more wood shavings and the manure broke down to nothing but ash.”

This spurred Logan to pursue his methane idea. He went to the Internet and located Dr. Richard Vetter, Ph.D., an agricultural engineer out of Chicago, who had worked years with anaerobic digesters in dairy and swine. John convinced Dr. Vetter to help him develop a digester.

Making a Case

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The company John Logan produces chickens for, Tyson, decided to move away from having their chickens bedded on wood shavings, opting instead for manure bedding. This spurred John to consider producing methane from the resulting litter.

Photo by Greg Gibson, Mississippi Farm Bureau Federation.

John next enlisted the help of a person he knew from his teaching years, a chemical engineer at Mississippi State University, Dr. Mark Zappi, Ph.D. “The USDA, Ag Star, everybody said it couldn’t be done with chicken manure. I was convinced it could,” John recalls. “So we did research on the manure to determine its potential for gas production.”

Dr. Zappi’s results were astounding, the gas potential from chicken litter out-performed dairy manure approximately 8 to 1 and swine manure about 5 to 1. Now the goal was to find a bacterium that could break the carbon out of the litter.

“We started doing research all across the country and found a suitable bacteria in a lab at West Virginia State University,” John says. “We went up there and loaded several truckloads of 55 gallon drums of the sub straight. We brought it down to my operation in Mississippi and used it in miniature laboratory digesters in a controlled environment.”

What they needed were bacteria that would work with chicken litter in the absence of oxygen, at temperatures around 130 and 140 degrees Fahrenheit. And they succeeded.

With the help of grant from Mississippi, John and Dr. Vetter built a prototype digester. After two years, John finally had a sufficient volume and quantity of bacteria to do what he needed done.

Developing Processes

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Managing the manure digester from a chemical standpoint is fairly complex. John’s background in computers has allowed him to help develop an elaborate process control system. The operator loads the chicken litter into the digester and then goes on about his business while a computer manages the process.

Photo By Greg Gibson, Mississippi Farm Bureau Federation.

With this success, John began applying for grants and has received six major ones so far. The first was used to create the digester and the second was to put in a solar system. “I just didn’t want to design and build a system that consumed more energy than it produced,” John says.

The 250,000 gallon digester requires a great deal of heated water and John uses solar energy to heat all the fresh water coming in and also for pumping water throughout his farm.

“We also established a recycle process,” he adds. “We filter and reuse about 80 to 90 percent of the liquid from the digester.”

It did not take long to realize that managing the digester from a chemical standpoint was fairly complex. John’s background in computers allowed him to get another grant from the USDA to develop an elaborate process control system. “Now the operator loads the chicken litter and then goes on about his business,” he explains. “The computer manages the whole process. It is able to actually take its own samples.”

John is pleased with the high quality gas. Predictions were 50 percent of that gas would be methane but they stand currently at 70 percent. They’ve also been able to reduce the hydrogen sulfide to less than one part per million by scrubbing it out with scrubbers designed by John and made from Canadian impregnated iron oxide rock.

Generating Electricity

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John realized that managing his operation’s manure digester from a chemical standpoint was fairly complex so he developed an elaborate process control system. The computer manages the whole process and even takes its own samples.

Photo by Greg Gibson, Mississippi Farm Bureau Federation.

The project also included installing a co-generation package – to generate electricity from the methane.

“It took me a year to get a contract with the power company to net meter,” explains John. “We don’t have net meter laws in Mississippi, so it was quite a cumbersome legal process and I had to hire a law firm.”
Today John saves the 8.5 cents per kilowatt-hour that he no longer has to purchase, and sells the remainder at three cents per kilowatt-hour.

Making the Most of Renewables
The farm does not let a BTU escape unused. In addition to the solar panels, John captures the heat from the exhaust and engines generating the power to help heat the water for the digester. He also had installed a wood-burning boiler to take advantage of downed wood from Hurricane Katrina.

“Maintaining the digester, plus the mixing water at high temperatures, it takes a good bit of energy. And all of my energy is coming from renewable sources,” John says proudly.

Bio Products

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Brinson Farms’ 10 broiler houses hold approximately 275,000 chickens, which produce around 1500 tons of litter a year.   

Photo by Therese Apel.

This would be the end of the story
for some, but not for John, who recognized valuable products coming from his digester.

“Poultry litter is a great nutrient source as fertilizer. And my process actually improved it,” John says. “Chicken manure is rated as a triple three – nitrogen, phosphorous and potassium. But now I’ve got a 6-3-5 nutrient value.”

Today the overflow from the digester is filtered to remove solids, creating an organic bedding material. And 50 percent of the liquid is used as a concentrated organic liquid fertilizer.

John received yet another grant to do market research on his value-added ‘bio products’ and he is discovering they may hold more value than the methane. He has already entered into a contract with a company to start marketing his products and foresees them being available nationwide.

Custom Digesters
Because the digester can be a tremendous revenue source for farmers, John has also begun selling his patented digesters. Six digesters are on the drawing board, with three under construction.

“A big benefit for farmers is that it allows them to get away from the CAFO requirements for managing the dry waste. He’s now into commercially organic products,” John explains.

His digesters are showing up in surprising places. One is to be attached to a meat processing company, blending scrap meat with the chicken litter. Another plant will be built at a large Mississippi Indian reservation to replace all their propane and a majority of their electricity. The plant will be fueled with litter from local farmers.

These local farmers are receiving more than premium price for their litter, John explains. “We buy the litter and when they need fertilizer, they can come back and get organic products from us – fertilizers that are manageable, easier to transport than raw chicken litter and don’t spread disease.” In fact, Logan will even rent the farmer handling and dispensing equipment.

Multiple Benefits

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The farm does not let a BTU escape unused. John has even installed a wood-burning boiler to help heat the water for the digester. It runs on downed wood resulting from Hurricane Katrina.   

Photo by Greg Gibson, Mississippi Farm Bureau Federation.

The digester project is saving Brinson Farms more than $100,000 a year in utility costs, but has also generated a host of other revenue generating opportunities:
• The revenue to be generated on the bio products cannot even be calculated yet.
• Eagle Green Energy was created, in part to test and size reactors to fit the manure sort.
• J&L Farmer Services, John’s construction company, has grown to 12 (plus contractors), and has moved from construction to solely digesters.

John is excited about the future. “We’re going into the commercial use of digesters and mutating new bacteria to fit other feedstocks. This gives us the ability to blend waste products and to generate a much higher carbon feedstock. We’ve done a lot of work in this area and have several opportunities.”

Not exactly the quiet life of the retired.