Designing for the Need: Effective Biomass Gasification

As more and more industries, manufacturers and municipalities look for ways to utilize biomass residues for energy, the Energy & Environmental Research Center is developing distributed gasification technologies as a means for conversion of biomass to fuels, chemicals and electricity. Several small gasifier systems have been tested with good success on a variety of biomass feedstocks, including wood, grass seed residue, switchgrass and sewage materials.

The concept involves first converting the biomass to a synthetic gas, which is cooled and then cleaned. The gas can then be fired in a generator to produce electric power or used as a feedstock gas for liquid fuels or chemicals. Most of the systems developed to date are distributed energy systems of 50 to 300 kilowatts of electricity in size. In many instances where an industry or municipality has ample biomass residue, the process residues produced can offset 100 percent of the power used in local industrial or manufacturing operations.

The residues produced at the plant are typically disposed of at a cost. The technology provides a means to use the material and benefit from the renewable energy product. Such projects can be thought of as a way to provide a fuel other than natural gas to an engine generator. The gasifier is a means to produce a usable fuel from biomass. Advances in gasification system design, operation and automation, although somewhat complex, have simplified things so that an operator primarily performs gas filter changes, ash collection and filling of a fuel bin.

What is significant about the technology with regard to biomass energy is the synergistic fit with typical biomass resources. Biomass, in general, is widely available as a resource. The most economical quantities of the material are located at specific sites in relatively low volume. The challenge has been to provide a distributed energy technology that can produce electricity at near-grid electricity prices. The EERC is developing gasification technologies that package power economically in a distributed power production scenario, as opposed to a large centralized power station scenario.

The EERC is working with commercial partners to provide not simply a hardware solution, but also a business solution. Because new products in the marketplace can face challenges, the business strategy of the EERC is to integrate for the customer the financial and operational benefits of small-scale biopower generation, which will allow development and confidence to sustain future business. The pathway forward provides a sustainable integration of new renewable energy to the marketplace.

Additional projects are planned over the next year, and all projects will support segments of the EERC's biomass gasification technology platform, which has a goal of moving technologies forward to stand-alone commercial operations within three years. Gasification technologies will, we hope, bring the economics of small-scale power generation within reach of commercial businesses attempting to find more attractive options for managing process residues.

Darren Schmidt is a research manager at the EERC in Grand Forks, N.D. Reach him at or (701) 777-5120.