§ 98.358 Definitions.

Except as provided below, all terms used in this subpart have the same meaning given in the CAA and subpart A of this part.

Biogas means the combination of CO₂, CH₄, and other gases produced by the biological breakdown of organic matter in the absence of oxygen.

Dry milling means the process in which shelled corn is milled by dry process, without an initial steeping step.

Ethanol production means an operation that produces ethanol from the fermentation of sugar, starch, grain, or cellulosic biomass feedstocks, or the production of ethanol synthetically from petrochemical feedstocks, such as ethylene or other chemicals.