Wisconsin Ruling Helps Biogas

October 03, 2003

The Wisconsin Natural Resources Board voted unanimously on September 25 to increase slightly the allowable nitrogen emissions from electricity generators using methane or other biogas fuels. Before this ruling, utilities and other generators were required to meet the same emissions standards as generators using natural gas. Biogas, which is produced in anaerobic digesters at landfills, municipal wastewater treatment plants, and farms, usually has a higher nitrogen content than natural gas. This fuel-bound nitrogen in biogas reacts with oxygen in the combustors inside power generating units to release higher levels of nitrogen oxides (NOx). On the other hand, biogas generators release lower levels of NOx than units firing on coal because coal has a greater amount of fuel-bound nitrogen than biogas. The ruling applies to counties in the southeastern part of the state that are out of compliance with federal clean air standards for ground-level ozone.

The ruling allows SC Johnson & Sons, Inc. to construct a pipeline from a landfill in Racine to its Johnson Wax plant. The company plans to use biogas from the landfill to generate electric power and steam at its Johnson Wax plant beginning in 2004.

Source: September 25 issue of the Milwaukee Journal Sentinel.