In a perfect world, fuel is plentiful, costs are predictable and boiler systems run smoothly. The real world, however, paints a very different picture, and much of the time fuel is the culprit. For non-utility sized projects (under 10 MWe or steam/heat-only plants) the simple addition of a burner, using an alternate fuel source, can add value by maximizing boiler operating hours and stabilizing costs.
The fuel dilemma
Boiler plant developers need a crystal ball. A boiler can last for decades, but fuel sources and prices change in an instant. If you’re old enough to read articles on energy technology, you’re familiar with quick and unpredictable changes in the cost and availability of different fuels. Just a quick glance at historical prices of oil and gas tells the unsettling tale.
Biomass a positive first step
Fortune 500 companies might have time to make adjustments when fuel prices spike, but for small businesses, municipalities and institutions, oil and gas price fluctuations can spell disaster.
It’s logical to see an increase in biomass-to-steam and/or power systems immediately following a spike in oil or gas prices, and environmental concerns add to the momentum.
In remote areas of Alaska, Hawaii and Canada, where natural gas is not available, biomass is an ideal primary fuel choice. The alternative is fuel oil, refined and imported by barge from out-of-state, resulting in prices that would shock residents of the continental U.S. For those developers who understand the benefits of biomass and move forward with projects, any barriers are secondary to the enormous potential cost savings.
Saving money through fuel diversification
A smart addition to most biomass boiler systems is a burner – natural gas, oil or even wood fuel-fired (for systems with gas boilers). Hurst Boiler & Welding Co. Inc. and Global Energy Solutions Inc. are seeing a trend emerge that helps mitigate the dilemma of fuel availability and stabilizes unpredictable costs. Burners can be added to a biomass project at the time of the initial design, soon after installation or several years after installation.
Adding a burner completes the project
Two recently completed biomass-to-steam projects offer a look at this creative solution. In both cases, natural gas burners have been incorporated to supplement the biomass-fired boiler fuel and guard against boiler down time. In both cases, the burners are capable of full firing and will serve as a fuel cost leveler. In the first example, the burner can be fully removed and replaced with a refractory plug that was designed with a customized mechanical arm that easily swings the plug into position. The second example shows a burner that was installed as a retrofit.
Case No. 1
Planned – Biomass boiler paired with natural gas burner and refractory plug. Oakdale Renewable Energy Plant — University of Iowa Research Park (Oakdale Campus), Coralville, Iowa.
An older gas-fired boiler was eliminated and replaced by a Hurst 600 BoHP biomass-fired boiler. In this example, the University of Iowa Facilities Management team incorporated a natural gas burner as part of the original system design, which includes a mechanism that swings the refractory plug into place when the burner is removed.
Case No. 2
Retrofit – Natural gas burner added to existing biomass boiler. Mullins Cheese Company, Mosinee, Wis.