Alaskan Brewing Burning Spent Grain As Fuel

The brewery began the spent grain energy process in 1995 with the installation of a grain dryer. The equipment dried the wet, protein-rich spent grain in preparation for shipment to the lower 48 for use as cattle feed, due to the absence of farms or ranches in Southeast Alaska. Alaskan Brewing  designed the grain dryer to use up to 50 percent of the grain as a supplemental fuel source to heat the dryer itself. This reduced the oil required in the drying process, & provided experience in burning spent grain that would later prove useful in designing the steam boiler.

In 2008, Alaskan Brewing became the first craft brewery in the nation to install an energy saving piece of brewing equipment called a mash filter press. The mash filter press, in addition to providing greater energy, water, and materials efficiencies, produces a lower-moisture-content spent grain than does the more traditional lautering process. This form of spent grain better lends itself to drying and for use as fuel for the brewery’s grain dryer and, ultimately, the new spent grain steam boiler system.

Over the latter months of 2012, Alaskan completed the final stage of the process with the installation and commissioning of the $1.8 million, custom-constructed spent grain steam boiler. This brewing byproduct is a unique and challenging fuel, so brewery engineers put their years of experience with drying grain to work with existing combustion technology to develop and fine-tune this first-of-its-kind process.

Alaskan Brewing expects that the new boiler will eliminate the brewery’s use of fuel oil in the grain drying process and displace more than half of the fuel needed to create process steam in the brewhouse. This translates to an estimated reduction in fuel oil use in brewhouse operations by more than half. With moderate growth assumptions, Alaskan expects to save nearly 1.5 million gallons of oil over the next ten years.
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