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SPRING 2009
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Made@CALS

Cornell Technology Makes Biogas Greener

By Marissa Fessenden '09

Cornell plant scientists have invented a method that uses manure and other farm byproducts to remove toxic hydrogen sulfide from biogas.

Hydrogen sulfide can combine with water to cause acid rain and to corrode engines, so its removal makes biogas a more viable alternative fuel source. The new method, marketed as SulfaMaster, could be used to sustain small farms and treat biogas derived from landfills.


Terrenew founders Terry Spittler, left, and Gary Harman show their
pilot system to remove hydrogen sulfide from biogas.
Joe Ogrodnick, NYSAES
Terrenew founders Terry Spittler, left, and Gary Harman show their pilot system to remove hydrogen sulfide from biogas.

"SulfaMaster has a very large potential application for distributed bioenergy production at small sites around the country," says Gary Harman, professor of plant biology at the New York State Agricultural Experiment Station in Geneva, N.Y.

Harman and Terry Spittler, a retired analytical chemist at Cornell, founded Terrenew, a company at the Cornell Agriculture and Food Technology Park in Geneva that markets SulfaMaster.

With more than nine million dairy cows in the United States, each producing an average of more than 120 pounds of manure daily, biogas is already a key energy source for many sustainable farms. It’s created by anaerobic digestion—a process where microorganisms break down manure and other organic matter in the absence of oxygen. The resulting biogas contains high levels of methane and carbon dioxide, but also a small amount of hydrogen sulfide.

Most methods for hydrogen sulfide removal require expensive industrial scrubbers that are not feasible for smaller farms. Terrenew’s process uses manure as a major component of a special medium, which is placed in barrels. "The gas is then piped into the bottom of barrels, [and as it] passes through the medium, the hydrogen sulfide is removed," Harman explains. "The resulting clean methane [plus carbon dioxide] can then be used for energy."

SulfaMaster also has promise off the farm. Biogas is prevalent in sewage treatment plants and landfills, especially those that accept construction and demolition waste. These sites can capture cleaner biogas and use it to power their operations.


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