The use of distributed power generation (DG) is a key player in fostering stronger economies in the developing world as well as in bolstering electricity generation in the U.S. at times of peak energy usage or in supplementing other clean energy technologies that may fluctuate with changing environmental conditions (e.g. wind and PV). Perhaps the biggest challenge facing the effective implementation of DG in the developing world is making technologies user friendly, both in the sense of having locally-produced fuels (from waste biomaterial) and machines that are easy to maintain and operate under harsh conditions. CSR is working with research collaborators to find a way to properly utilize waste stream biomass to generate electricity.

The Natural Resources Research Institute at the University of Minnesota is Principal Investigator and leader on a $1.9 million Renewable Development Fund grant funded through Xcel Energy to develop a Biofuel Conversion Center at the NRRI Coleraine Lab. The Coalition for Sustainable Rail is one of two industry partners aiding NRRI on the grant; its responsibility includes designing and building a 100 kW steam-electric boiler generator. The other industry partner, SynGas Technology, LLC, is championing development of a proprietary moving bed torrefaction reactor to supply fuel to the boiler generator. 

“The steam-electric generator the CSR engineering team is designing will be a one-of-a-kind addition to our Biofuel Conversion Center, and it will serve as an important research tool in the development of remote, distributed generation systems," explained Don Fosnacht, Ph.D., NRRI Associate Director, CSR Board Member, and the project’s Principal Investigator.

The steam-electric generator being developed by CSR will employ an advanced locomotive-style boiler and compound expansion piston steam engine to generate sufficient power to make 100 kW of electricity. The boiler is designed to burn torrefied biomass fuel in a Gas Producer Combustion System and will be able to operate automatically, thanks to an additional $25,000 National Instruments Green Engineering Grant awarded to CSR in support of the RDF project.

“The Xcel grant provides a significant opportunity to push the state-of-the-art in firetube boiler, compound reciprocating steam engine, solid fuel combustion, and distributed generation system design,” said Wolfgang Fengler, MSME, CSR Senior Mechanical Engineer. “Developing an efficient boiler-generator package that can fit into a 20 foot shipping container is no small task, but our experienced team brings a diverse skillset that has translated into an innovative concept which we are eager to fashion into a working prototype.”

The NRRI RDF Grant is broken into multiple milestones, including preliminary engineering, detailed engineering, fabrication, testing, and steady state operation phases. 

“What the RDF grant has enabled CSR to do is really push boiler and steam piston engine design as can only be achieved through new-build construction,” explained CSR Technical Advisor Hugh Odom, P.E. “I am honored to serve as the Professional Engineer on this project, working with the CSR engineering team in a capacity to verify compliance of the design with ASME and other applicable codes.”

When completed, the boiler generator unit will be installed at NRRI’s Biofuel Conversion in Coleraine, Minnesota, where it will undergo commissioning and steady state operations. That facility is a former Oliver Iron Mining Railroad maintenance complex which has been converted into a one-of-a-kind minerals and biofuel research center by NRRI.