Environmental Engineering Reference
In-Depth Information
practical to produce large quantities of vegetable oil that could fulfill the transportation needs of a
society. Algaculture professionals believe that it can be done.
In the United States, the Office of Fuel Development funded research from 1978 to 1996 to
determine the feasibility of using algae for oil production. The results of the Aquatic Species
Program concluded that algae farms in the United States have the potential to supply biodiesel that
can satisfy not only the transportation needs of the United States but also replace existing home
heating oil (Briggs 2004). Optimism in algaculture remains high as various studies have provided
evidence that one day vegetable oil from algae may provide the needed feedstock to replace diesel
and home heating oil. According to one such report, the yield per acre of oil from algae is over 200
times the yield from the best performing vegetable oil seeds (Sheehan et al. 1998). Another recent
study (Wagner 2007) concluded that per unit area yield of oil from algae is estimated to be 5,000-
20,000 gal/acre, which is 7-31 times greater than the next best crop, palm oil. The most important
aspect of algaculture is that it does not entail a decrease in food production because production of
algae is not dependent on any farmland or fresh water. A large number of companies are emerging
(http://peswiki.com/index.php/Directory:Biodiesel_from_Algae_Oil) which have plans to produce
algae in open ponds or by other methods.
Hydrogenated vegetable oils (HVO) are also being looked at as the second generation of
biodiesel (Arvidsson 2008) and have been termed “hydrotreated biodiesel.” The HVOs are straight-
chain paraffinic hydrocarbons that are free of aromatics, oxygen, and sulfur. They have high cetane
numbers and are devoid of detrimental effects (i.e., increased NO
x
emission, deposit formation,
storage stability problems, more rapid aging of engine oil or poor cold properties) of traditional
ester-type biodiesel fuels (Aatola et al. 2009). Proprietary commercial hydrotreated biodiesels are
appearing on the market and are claimed to perform better than rapeseed methyl esters or biodiesel
(http://www.greencarcongress.com/2006/03/neste_oil_and_o.html).
18.1.4 o
thEr
B
ioEnErgy
u
SES
of
v
EgEtaBlE
o
ilS
Besides transportation, there are various other energy uses of vegetable oils, which include
home heating and electricity generation. At home, either vegetable oil or biodiesel can replace the
No. 2 heating oil used in furnaces and boilers. The primary advantage of utilizing vegetable oil in
home heating appliances is the lower price which can be significant for a small business or home
owner. In a farm energy case study in Old Athens Farm at Westminster in Vermont, the owner replaced
the No. 2 heating oil with vegetable oil and was able to save approximately U.S.$3,600 in the winter
of 2005/2006 and almost U.S.$9,000 in 2008 by burning 4,000 gals of vegetable oil (Grubinger 2008).
Vegetable oil is also used for electricity generation in small power plants. The use of vegetable oil
in this application is significantly limited because of the large deposits of coal in the earth's surface.
Although oil reserves in the Earth's crust are limited, scientists are more concerned with replacing
liquid fuel such as diesel and petroleum with vegetable oil instead of replacing coal in electricity
generating plants. Nevertheless, it is estimated that refined vegetable oil, although viscous, is well
suited to large, low-speed engines that are used in power stations (vegetable oil power stations).
These diesel reciprocating engines are widely used in power plants ranging in size from 1 to 17 MW
and are specifically designed to run on heavy oil similar to refined vegetable oil.
18.1.5 i
mportancE
of
b
rAssicA
o
ilSEEdS
aS
B
ioEnErgy
S
ourcE
Like other vegetable oils, Brassica oils have a history spanning over thousands of years as sources
of edible oil for humans and protein feed for animals. However, rapeseed oil has also been an
important source of energy for many non-food purposes. For example, the oil from rapeseed has
been used for light (oil lamps) and heating for centuries in India and China. Today, canola/rapeseed
oil is considered an important component of the bioeconomy and/or bioenergy. Some examples
are the production of bioenergy heaters, stoves, and furnaces (http://www.thermobile.co.uk/bio.asp;
