For those who don't know what Biomass is, it is energy that is generated using organic minerals from the earth that can be either renewable or nonrenewable. Wood was once our main fuel. We burned it to heat our homes and cook our food. Wood still provides a small percentage of the energy we use, but its importance as an energy source is growing thin. Wastes such as animal manure, wood chips, seaweed, corn stalks, and even trash can even be broken down into usable energy. "Bioconversion" uses plant and animal wastes to produce "Biofuel" such as methanol, natural gas, and oil.
Advantages: It makes sense to use waste materials where we can. The fuel tends to be cheap, and there is less demand on the fossil fuels.
Disadvantages: Collecting or growing the fuel in sufficient quantities can be difficult. We burn the biofuel, so it makes greenhouse gases just like fossil fuels do, and some waste materials are not available all year round.
http://www.darvill.clara.net/altenerg/biomass.htm#intro