As managers and developers know, working through any retrofit project is more interesting than new construction, but also more challenging. When a construction management team is assembled to repurpose an existing site, it usually means space restrictions, unusual piping, creative wiring and many customized solutions worked out in the field.
A new biomass boiler installation at the University of Iowa, commissioned in early 2012, was no exception. As part of the Oakdale Renewable Energy Plant (OREP) infrastructure overhaul, the wood-fired boiler is one of many steps in a complex green energy initiative launched by the university and praised by the DOE.
Biomass decisions begin with the fuel
Global Energy Solutions Inc. (representing Hurst Boiler) was approached by Ferman Milster, University of Iowa’s associate director, Utilities and Energy Management, to brainstorm a potential biomass boiler solution for the Oakdale Research Park facility. This process began before the Iowa City flood of 2008. According to Milster, the plan was to install and operate a biomass boiler (replacing one of 4 gas boilers) and to fire it with local fuels such as wood chips and oat hulls, utilizing an existing coal bunker for fuel storage. The overall goal was to operate the U of I’s Research Park campus on 100 percent renewable energy, with fossil fuels in place for backup.
Working together to shape the renewable energy project with Milster were Albert Ratner, assistant professor of mechanical and industrial engineering, and Barry Butler, U of I professor of mechanical and industrial engineering and dean of the College of Engineering. Their ongoing efforts have been rewarded since the university has been listed in The Princeton Review’s Guide to 322 Green Colleges for three consecutive years.
The Oakdale Research Park boiler system
In July 2010, the decision was made to approve fabrication of the new biomass system, and so the university facilities management team began the collaborative process laying out the puzzle pieces and attempting to determine how and when everything would fit together. Once the equipment was on-site, weekly meetings were held to assess progress, discuss necessary adjustments and sort out responsibilities. As expected, the coordinated effort required creativity, layout changes and compromise – the hallmark of seasoned manufacturers and installation specialists.
An agricultural waste gasifier adds complexity
Tied into the biomass boiler system is a small gasifier provided by Ag Bio-Power of Tama, Iowa. The gasifier is an integral system component to be used by the U of I College of Engineering for ongoing combustion research and study of locally obtained alternate renewable fuels such as expired seeds, corn stover and paper sludge. Agricultural products are introduced into the gasifier to produce syngas that is injected into the burner. The gasifier is essential to the OREP since the university seeks to explore new fuel technologies and serve as a model for other university communities.
Installation and start-up
There is no substitute for experience, according to Bruce Coffee, chief engineer at Hurst Boiler & Welding Co. Inc., who has been solving complex biomass scenarios for 30 years.
“When it comes to biomass projects, experience is the most critical factor for a smooth and successful retrofit,” he said.
Coffee is one of Hurst’s many boiler experts who provide hands-on technical assistance and training in the field, and while he would not describe the University of Iowa project as difficult, it did require some creative solutions, including modifications to work around space constraints and fixed barriers. Components such as the boiler legs, breeching (ductwork), piping and the fly ash collector chute were all puzzle pieces that needed to be modified and placed to fit.
“The rougher it is,” he said, “the better we like it.”
Training is critical
Occasionally, experienced boiler technicians – oil, gas or coal – will make the assumption that operating a new biomass boiler does not require any specialized training. The U of I project involved an academic group, and they knew better than to make assumptions without first conducting research. As expected, the training classroom for this project was filled with managers, boiler operators, engineers and other technicians ready to learn all they could about the new technology.
James Alwin, PE, of Global Energy Solutions Inc., served as a liaison between U of I and various manufacturers throughout the project. He attended the training as well, understanding that there is always something new to learn about these systems.
Beyond the operation of the boiler, there are many moving parts in a biomass system requiring periodic maintenance and adjustment – particularly if a new fuel is being introduced. Hurst Boilers can combust hundreds of different fuels, but adjustments are usually required to accommodate changes or mixtures.
The OREP includes an ambitious series of projects that, when completed, will serve the university Research Park Campus with 100 percent non-fossil fuels.
Natalie M. Smith works for Global Energy Solutions Inc. in Naperville, Ill., which manages marketing for Hurst Boiler. You may contact her by e-mailing email@example.com.