does sewage consider as biomass?

Answer 1

There are processes that dry and burn sewage (I think producing some power), but not commonly considered as biomass.

Answer 2

It depends on what industry that you use the term biomass. I work at a trucking company that is in the forestry business. We haul forest byproducts like lumber, wood chips, rough green, and biomass. Biomass means fuel, which several of the larger paper companies use to fuel their plants instead of fossil fuels.
Just a piece of neat info!