Page 276 - Biosystems Engineering

254 Cha pte r Ei g h t

income distribution. Furthermore, production of biodiesel reduces
dependence on foreign supplies, saves a lot of funds on imports of
7
diesel, and is helpful in counteracting inflation. It is widely agreed that
biodiesel decreases emissions of hydrocarbons (HC), carbon monoxide
(CO), particulate matter (PM), and sulphur dioxide (SO ). Only nitro-
2
gen oxides (NO ) are reported to increase, which is due to the oxygen
x
content in the biodiesel. 8–10 NO is also said to be carbon neutral because
x
it contributes no net carbon dioxide to the atmosphere. 11–13
Processing vegetable oils to biodiesel 1,8,10 and its applications has
several advantages such as the following:
1. Technologies for extraction and processing are very easy and
simple, as conventional equipment with low energy inputs
are needed.
2. Fuel properties are close to diesel.
3. Vegetable oils are renewable in nature.
4. Being liquid, biodiesel offers ease of portability and possesses
stability and low handling hazards.
5. The by-product leftovers after extraction of oil is rich in pro-
tein and can be used as animal feed or solid fuel.
6. Cultivation of oil-producing plants is flexible to a wide range
of geographic locations and climatic conditions.
7. Biodiesel can be used directly in compression ignition engines
without substantial modifications of the engine.
8. Biodiesel does not emit sulphur oxides.
9. Biodiesel reduces the exhaust emissions in diesel engines
without significantly affecting engine performance.

Different oils have been used in different countries as raw materi-
als for biodiesel production (e.g., soybean oil is commonly used in the
United States, rapeseed and sunflower oils are used in many European
countries, and coconut and palm oils are used in Malaysia). 14–17 Most
of these oils are edible and are costlier than nonedible oils as needed
for human consumption. Thus, nonedible oils will be economical to
use in internal combustion engines. Furthermore, the main economic
criteria are considered to be manufacturing cost and price of raw
feedstock. Manufacturing costs include direct costs for oil extraction,
reagents, and operating supplies, as well as indirect costs related to
insurance and storage. Fixed capital costs involved in the construc-
tion of processing plants and auxiliary facilities, such as distribution
and retailer costs, must also be taken into consideration.
To promote biodiesel consumption, several countries exempted
biodiesel from the fuel excise tax. Among them, the European Union
approved the biodiesel tax exemption program in May 2002; the
financial EU law funds biofuels through excise exemption over a