Biomass/Bioenergy - Environmental Impacts of Renewable Energy - page 200

1. Sugar and starch bioproducts derived through fermentation and thermo-
chemical processes include alcohols, acids, starch, xanthum gum, and other
products derived from biomass sugars. Primary feedstocks include sugar-
cane, sugarbeets, corn, wheat, rice, potatoes, barley, sorghum grain, and
wood.
2. Oil- and lipid-based bioproducts include fatty acids, oils, alkyd resins,
glycerine, and a variety of vegetable oils derived from soybeans, rapeseed,
or other oilseeds.
3. Gum and wood chemicals include tall oil (liquid rosin), alkyd resins, rosins,
pitch, fatty acids, turpentine, and other chemicals derived from trees.
4. Cellulose derivatives, fibers, and plastics include products derived from
cellulose, including cellulose acetate (cellophane) and triacetate, cellulose
nitrate, alkali cellulose, and regenerated cellulose. The primary sources of
cellulose are bleached wood pulp and cotton linters.
5. Industrial enzymes are used as biocatalysts for a variety of biochemical
reactions in the production of starch and sugar, alcohols, and oils. They
are also used in laundry detergents, tanning of leathers, and textile sizing
(Uhlig, 1998).
BIODIESEL
The diesel engine is the workhorse of heavy transportation and industrial processes;
it is widely used to power trains, tractors, ships, pumps, and generators. Powering the
diesel engine is conventional diesel fuel or biodiesel fuel. Biodiesel is a rather vis-
cous liquid fuel made up of fatty acid alkyl esters, fatty acid methyl esters (FAMEs),
and long-chain mono-alkyl esters. It is produced from renewable sources such as
new and used vegetable oils and animal fats and is a cleaner-burning replacement for
petroleum-based diesel fuel. It is nontoxic and biodegradable. This fuel is designed
to be used in compression-ignition (diesel) engines similar or identical to those that
burn petroleum diesel. Biodiesel has physical properties similar to those of petroleum
diesel (see Table 5.9 ) . In the United States, most biodiesel is made from soybean oil
or recycled cooking oils. Animal fats, other vegetable oils, and other recycled oils
can also be used to produce biodiesel, depending on the costs and availability. In the
future, blends of all kinds of fats and oils may be used to produce biodiesel. Before
providing a basic description of the vegetable and/or recycled grease to biodiesel
process, it is important to define and review a few of the key technological terms
associated with the conversion process.
DID YOU KNOW?
There is a reason for the costly side of biomass energy. To generate electricity
from biomass, a massive amount of biomass is required to produce biofuel.
The availability of biomass fuel sources is not consistent, as reliance on the
forest and agriculture residual sources is quite uncertain (Karthick, 2010).