Biomedical Engineering Reference
In-Depth Information
Chapter 1
A
R
EVIEW OF
B
IODIESEL
AS
R
ENEWABLE
E
NERGY
John Chi-Wei Lan
1
, Amy Tsui
2
, Shaw S. Wang
1,2
and Ho-Shing Wu
1
1
Department of Chemical Engineering and Materials Science, Yuan Ze University,
ChungLi, Taiwan
2
Departement of Chemical and Biochemical Engineering, Rutgers University, The State
University of New Jersey, United States
Abstract
Increasing demand and price of fossil fuel has been a challenge for world scientific
researchers and governments which results in a huge impact upon economic development.
Biodiesel, as an alternative diesel fuel that can be generated from renewable sources such as
animal fat, vegetable oils, and recycled cooking oil, seems to be a promising solution for
future in a sustainable manner with respect to energy security and reduction of green house
gas (GHG) emission. This article is a review of development of biodiesel processing
technology, use of varied biodiesel in diesel engines and analysis of economic scale and
ecological impact of biodiesel fuel.
Biodiesel can be produced either by chemical (pyrolysis, microemulsification, solid-
liquid phase conversion, and transetherification) or biochemical (lipase) methods. Some
scientists also demonstrated the potential of employing microwave irradiation or supercritical
fluid for derivation of biodiesel. However, the most common process for commercial biodiesel
production is to apply alkali as catalyst and mix with methanol for the formation of fatty acid
methyl ester (FAME). It has been produced more than 10 millions tonnes of biodiesel and
applied as B5 or B20 product in the market.
Most of conclusions from research reports of emission test of different biodiesel
resources indicated a significant decrease in particular matter (PM), hydrocarbons, SOx and
CO
2equ
at global level but slightly increase in NOx and CO or CO
2
. A research investigated the
characteristics of mutagenic species, trans,trans-2,4-decadienal (tt-DDE), and polycyclic
aromatic hydrocarbons (PAHs) in the exhaust of diesel engines operated with biodiesel blend
fuels made from recycled cooking oil. It showed that tt-DDE and PAHs tend to accumulate in
particulate for cold-start driving. Despite of its advantages on environmental protection, the
lubricant properties of the biodiesel are able to extend the engine life but oxidation of
