Those involved in the biomass gasification system project include, from left, Dave Prouty, president of Heat Transfer International; Rick and Harley Sietsema. Harley owns Sietsema Farm Feeds.
HTI builds 1st biomass energy plant
Pete Daly
A Kentwood company has completed a biomass energy plant at a feed mill in Howard City that may be the first of its kind and could dramatically increase its owner's energy independence.
"It will be the first biomass turbine assembly powered by manure in the world," said David Prouty, president of Heat Transfer International.
The biomass gasification power generation system that HTI designed, manufactured and installed at Sietsema Farm Feeds turns turkey litter into syngas — similar to natural gas — that is then used to make heat and electricity required in the production of turkey feed. A modified turbine engine of the type used in the Cessna Citation business jet is powered by the oxidizing syngas to generate electricity. HTI worked closely with Williams International, a Walled Lake company that made the turbine and specializes in small gas turbine engines.
The SALT retort was expected to begin operating in late August or early September and will be tested for several weeks, with a formal celebration of the opening of the unique energy plant planned for October. It was three years in construction.
SALT stands for starved air/low temperature. The device works like an oven that "bakes" any type of organic matter in an oxygen-starved environment. Most of the turkey litter “turns into this combustible gas," said Prouty, leaving only a small amount of ash that has value as fertilizer.
"The USDA has said, ‘If this works like you guys say it will work, we will roll it out to every agribusiness organization in the country,'" said Prouty.
The U.S. Department of Agriculture provided Sietsema Farms Feed with a $500,000 rural development grant toward the project, after the Michigan Department of Agriculture provided an initial $200,000 Agricultural Innovation Grant for a study that demonstrated the feasibility of using turkey litter as an energy source.
Gasification is not new: Coal was being gasified one hundred years ago, and the resulting coal gas — also called "producer gas" or "town gas" — was burned in street lights across the country. During World War II, nearly one million cars in Europe were run on producer gas because of the lack of conventional gasoline.
However, Sam Hogg, a biomass market specialist at NextEnergy in Detroit, said the Sietsema feed mill project probably is the first biomass-to-electricity system using "an air turbine, for sure." NextEnergy is a nonprofit organization promoting investment in wind, solar, new battery technology and other related alternative energy markets.
Hogg said he believes few companies in the world have the expertise in biomass technology that HTI has.
Prouty was one of the founders of Thermocon Corp. in Dutton, which customizes and modifies standard commercial heating and air conditioning equipment. In 2005, Thermocon launched a new division: HTI. One year ago, Prouty sold his ownership in Thermocon and bought 100 percent of HTI, then moved it to Kentwood. He said he bought HTI "because I think this is where the fun is and (where) the world is headed."
Today, HTI employs a dozen people, including a man described by Prouty as "the Albert Einstein of gasification in the world”: Robert G. Graham.
Graham, HTI's senior application engineer, has worked in waste material gasification and high-temperature combustion equipment for more than 40 years. In 1982, he set up an R&D program to perfect an all-ceramic heat exchanger for use in industrial process furnaces, and was granted several patents in the process.
Prouty said HTI now owns the intellectual property developed by Graham.
"He is the reason we are as far along as we are" in waste gasification, said Prouty.
HTI now has the capability to make ceramic heat exchangers that can operate at temperatures of up to 2,400 degrees F and high pressure of 150 psig, according to Prouty. That temperature is 50 percent higher than what most exotic metal heat exchangers can tolerate.
HTI has had four patents issued in the past three years, with eight more in process, according to Prouty.
Prouty said Harley Sietsema is also "a pioneer" in waste biomass gasification. Sietsema, who lives in Allendale and owns Sietsema Farms Feed, also owns or has interests in West Michigan farms that raise a total of 1.3 million turkeys per year. The resulting turkey litter — wood shavings from sawmills used as bedding, which has been fouled by the birds' droppings — totals about 14,000 tons per year.
Sietsema said his energy bills for the Howard City feed mill are about $500,000 per year. The new biomass gasification plant is designed to produce about 460 kilowatts of electricity — enough for about 400 homes, according to Prouty, and it also produces enough heat to warm about 150 homes on the “coldest Michigan winter day."
Sietsema said he expects the feed mill "to be in a position to replace nearly all the natural gas and the majority of the electricity we currently consume."
"Our system is a baseload (generation system)," said Prouty. "It runs at full speed 24 hours a day, seven days a week. It makes full power all the time" — unlike wind and solar energy devices.
Sietsema said several million dollars have been invested in the biomass plant and "the return on the investment is going to be several years, for sure." The actual return will depend in part on the market value of the excess electricity they produce, he said.
Sietsema said that several years ago, he and several other turkey producers had a feasibility study done on potential alternative energy, but based on the technology available then, the ROI was not good enough. He said the person who later helped them "spark this project anew" was Norma McDonald of Phase 3 Renewables in Cinncinnati, who worked as a consultant to help Sietsema evaluate the different technologies and apply for grants.
"We did a worldwide search of all the different technologies and companies" that could use turkey litter as an energy source, said McDonald. She contacted 17 of them and got quotes from 10 for design and construction of a thermo-conversion process using either gasification or pyrolosis, which turns organic matter into a liquid fuel.
They ended up selecting companies that were in Michigan, she noted.
"This is the first true gasification plant in Michigan," she said. "There are other incineration plants (using biomass) but not this type of gasifier technology," adding that this is the first time this combination of equipment and technology has been used together.
Sietsema said he has been told that when all the syngas is cooked out of the turkey litter, from 15 to 17 percent of it remains as ash, but McDonald said it might be as low as 12 percent. Since this is "the first” of its type to be put into operation, she said, they can only estimate the amount of ash that will be left in the Howard City biomass energy plant. Prouty said some forms of biomass, such as certain hardwoods, can be gasified down to an ash remnant of less than 5 percent of the original quantity, by weight.
Up to now, Sietsema has sold the turkey litter to other farmers for use as fertilizer. However, he won't be out of the fertilizer business; in fact, it may be a more efficient business.
With gasified turkey litter, the majority of the fertilizer nutrients, other than nitrogen, are still in the remaining ash, he said. Now, however, the remaining phosphorus and potash will be concentrated, without the inert ingredients that they had been trucking to farms before when delivering the turkey litter as fertilizer.
McDonald said that it takes a very small amount of natural gas "on day one" to ignite the turkey litter in the SALT retort. Once ignited, no more natural gas is required to keep it cooking, she said, and it will keep on cooking as long as more litter is added.
Prouty said biomass gasification has huge potential as an alternative to fossil fuel because there is so much biomass available, especially in Michigan agriculture. The organic content of household trash and sewage can also be gasified, he noted.
"Everyone has garbage, waste," said Prouty. "It's always considered a liability. Let's do something useful with it instead of trucking it (to landfills) and burying it."
"Everybody talks about wind and solar, which don't have near as much potential as biomass," said Prouty. He said there are "a number of quiet developers out putting deals together, all built around biomass. You just never hear about it."
There are also groups working to develop a practical method for making liquid fuel for vehicles from biomass, he said. |