The Windsor Village Elderly Housing facility in Windsor, Vt., occupies what used to be the state’s oldest prison, and had all of the old basement jail cells intact until recently. With the installation of a biomass boiler, a few changes had to be made.
The housing facility allowed its tenants to use the basement cells as secure storage units, but now the converted building, dating back to 1808, is almost jail cell-free. “We commandeered two groups of five (cells),” David Frank, co-founder of Vermont-based biomass project integrator and developer SunWood Biomass, says of his team’s work in transforming the historic building. He and his workers knocked down the walls between the cells with a jack hammer to create a long trough that would eventually feature a V-bottom interior storage design for wood pellets.
“We almost lost that project because of the historical preservation folks,” Frank says. Those folks, he explains, did not want the grounds outside the two-century-old building to feature a storage silo for the pellet feedstock. So SunWood got creative.
The team adapted a run of pneumatic piping into six filling ports that opened into the jail cell trough. Roughly 100 feet separated the filling ports from the pellet delivery location. The piping is traditionally used in the food industry to move product between storage and processing because it offers the least amount of friction and resistance.
SunWood had to determine what air volumes and pressures were required to send the pellets from the truck to the six ports, Frank explains. “We used a couple of suppliers to help us run the test in a warehouse to see if it could be done and if the pellets wouldn’t be damaged.” They proved it was possible, and the pellets weren’t damaged, making the hidden project a success without any impact on the old facility’s character.
Today, SunWood Biomass is working on six other historic preservation sites where silos cannot be used. Project developers like Frank have plenty of similar stories about projects in the wood pellet industry. It’s an industry with a surplus of ingenuity, creativity and innovation.
Averill Cook of Massachusetts-based Biomass Commodities, is in Serbia helping Michelin Tire develop an effective practice to pelletize its tires. Cook knows all about the impact creative thinking can have on a difficult project, having already completed roughly 25 pellet boiler installation jobs with his team. “I think that the industry is getting more installations and being more recognized, and the concept is growing,” he says.
The availability of biomass boilers in the U.S. is indeed growing and that is where Cook sees the most innovation in the industry. Cook and his team are working with an engineering firm to install a boiler system at a community college in the Northeast. He hopes the project will start a new market. “The system is unique because it pulverizes the pellets into dust and sprays them in,” he explains.
Although this type of boiler has been around for some time, Cook says clients looking for district heating applications could benefit from employing it. The technology can be more easily retrofitted into existing boilers than a standard pellet system, and is more versatile and efficient because it is dual fuel, he explains. Operators can play the market by running different types of fuel or pellets.
Tom Miles, founder of T.R. Miles Technical Consultants Inc., shares Cook’s sentiments about the evolving landscape of biomass boilers.
“One thing that is kind of striking or compelling is the success of what they have been calling in places like Alaska the boiler in the box,” he says. The set-up utilizes a boiler placed in a durable container and installed over a poured slab roughly 15 feet by 20 feet. The simple installation can be done efficiently and economically, Miles says, citing an application at an airport in Oregon.
The boiler-in-a-box option saves money because it doesn’t require a developer to build a separate building for a boiler, or to shoehorn one next to an existing heating appliance, Miles says. “I think that these kinds of easy-to-install, lower-cost pellet boilers are probably a good bulk market expansion strategy for these pellet producers.”
Miles hopes further innovations in boiler set-ups can correlate to the use of lower-grade fuel pellets. “The reality is, to be practical and economical, we need to be able to handle pellets that don’t necessarily meet the residential standard,” he says. “If boilers were designed with staged combustion and staged gasification that would handle higher ash fuel…you could open up potentially lower-cost fuel markets.”
Miles, Frank and Cook all believe access to boilers manufactured in the U.S. offer their clients more options for projects in North America. And they all agree that innovation plays a huge role in biomass boiler development and conveyor system designs, whether they’re for a jail cell or underneath a parking lot.
Like boilers, pellet conveyor and delivery system installations can also use a little ingenuity. Cook has completed a project that required moving pellets on a conveyor belt underground, below a parking lot. Biomass Commodities also has a number of projects where storage silos are more than 200 feet from the boiler room. Such challenges can be overcome, but the most difficulty comes when engineers and architects don’t understand fuel pellet handlings. “When they do a drawing with a right angle on a fuel conveyor, you have to tell them, ‘That is not going to work,’” Cook says.
Frank and Cook are always discovering innovative ways to move pellets and fortunately, pellet delivery trucks in the Northeast U.S. have evolved. When Frank first started helping clients bring in pellets, the norm was to use grain delivery trucks that featured a conventional airlock system. Today he uses trucks developed in Europe specifically for pellets that reduce breakage during delivery.
Enviva LP is yet another leader in pellet industry revolution. Its Port of Chesapeake, Va., storage silo dome, 157 feet tall and 175 feet wide, can withstand hurricane force winds and earthquakes, while maintaining a controlled temperature for optimal pellet quality. It allows storage of up to 50,000 metric tons of wood pellets. “It is critical for us to have a storage system that is designed specifically for wood pellets,” says Elizabeth Woodworth, the company’s director of marketing, communications and sustainability. The system, she says, includes more than 100 temperature sensors that allow an operator to monitor the temperature of the stored pellets at any time via computer screen. That operator, she adds, can control the temperature of the dome by switching a ventilation system on or off. Woodworth says there is virtually no chance of fire or sparks because Enviva is currently installing an injection system to put out any sparks. Of all the elements that make the system innovative and unique, Woodworth says safety is the number one aspect the company was focused on when it designed the dome.
Clearly, pellet use today is a combination of creative thought and remarkable implementation skills. In the Northeast alone, Frank and Cook have completed installations at churches, garages, schools, old prisons, and firehouses. Frank also has projects in Utah, Alaska and elsewhere. “We completed a project with a fire department where they didn’t want the sight of a silo outside a brand new modern-looking building,” Frank says. So he and his team crafted an artificial tower, similar to those used for hose drying, for pellet storage.
People are Talking
Cook says such ingenuity in the pellet industry is drumming up more discussion. “The culture is starting to turn and with the higher oil prices people are going to start looking more at this,” he says. That means school districts looking to save money, new hospitals looking to secure future heating costs at a stable price, or the engineers who help design the projects. “The engineering firms keep on coming back,” he adds. “They are excited about [pellet projects] and they are very proud of it. They start to tell more people about it and the snowball is getting big.” And with oil prices rising, that snowball is only going to roll faster.
Frank would agree. “The initial adoption curve was very steep, but now it is becoming fairly prolific in terms of acceptance, and engineers are even suggesting planning [pellet boilers] into a project.” He attributes that turn of events, in part, to the fact that the necessary equipment already exists, even though each job will bring new project planning and implementation strategies. And with further innovation still coming down the pike, the job will only get easier, and busier.
Author: Luke Geiver
Associate Editor, Pellet Mill Magazine