Two-
Variable
Alkaline
Acid
Step
Ultrasonic
Lipase
Supercritical
Reaction
40–70
55–80
40–70
30–40
30–403
240–385
temperature (°C)
Yield
Normal
Normal
Good
Higher
Higher
Good
Glycerol
Difficult Difficult Difficult
Difficult
Easy
—
recovery
Purification
Washing Washing Washing Washing
—
—
of ester
Production cost
Cheap
Cheap
Cheap
Medium
Expensive
Medium
58
Alternative Fuels for Transportation
TABLe 3.3
Comparison of Biodiesel Production Methods
Biodiesel production process is classified into two: batch and continuous
process. In batch production process, measured quantities of reagents are
charged and reaction taken place at prescribed conditions. For the base catalyzed transesterification process, stainless steel material is used for the fabrication of the reactor.
In continuous process, reactants are fed into one side of the reactor. The
chemical composition changes as the reactants moves in plug flow through
the reactor. Gear pumps are used for transferring the reactants and products from one place to another. The separation of biodiesel and glycerol is
achieved by using a settling tank. Though settling is cheaper, centrifuge can
be used to increase the rate of separation relative to a settling tank. Separation
is accomplished by exposing the mixture to a centrifugal force. The denser
phase is separated to the outer surface of the centrifuge. Distillation column
separates the fluids with similar boiling points.
3.4 Biodiesel Properties
Biodiesel fuel quality depends upon composition of feedstock, production
process, storage, and handling. Biodiesel quality is evaluated through the
determination of chemical composition and physical properties of the fuel.
Contaminants and other minor components, due to incomplete reaction, are
the major issues in the quality of biodiesel (i.e., glycerol, mono, di, triglycerides, alcohol, catalysts, and FFA present in the biodiesel). Moreover, biodiesel composition could be changed during storage and handling. Biodiesel
can absorb water or undergoes oxidation during storage. Therefore, significance of these parameters and their analytical or engine test methods
are addressed in standards. Each country has its own fuel quality testing methods and standards to specify the properties of the fuel. Here the
Variable
Alkaline
Acid
Step
Ultrasonic
Lipase
Supercritical
Reaction
40–70
55–80
40–70
30–40
30–403
240–385
temperature (°C)
Yield
Normal
Normal
Good
Higher
Higher
Good
Glycerol
Difficult Difficult Difficult
Difficult
Easy
—
recovery
Purification
Washing Washing Washing Washing
—
—
of ester
Production cost
Cheap
Cheap
Cheap
Medium
Expensive
Medium
58
Alternative Fuels for Transportation
TABLe 3.3
Comparison of Biodiesel Production Methods
Biodiesel production process is classified into two: batch and continuous
process. In batch production process, measured quantities of reagents are
charged and reaction taken place at prescribed conditions. For the base catalyzed transesterification process, stainless steel material is used for the fabrication of the reactor.
In continuous process, reactants are fed into one side of the reactor. The
chemical composition changes as the reactants moves in plug flow through
the reactor. Gear pumps are used for transferring the reactants and products from one place to another. The separation of biodiesel and glycerol is
achieved by using a settling tank. Though settling is cheaper, centrifuge can
be used to increase the rate of separation relative to a settling tank. Separation
is accomplished by exposing the mixture to a centrifugal force. The denser
phase is separated to the outer surface of the centrifuge. Distillation column
separates the fluids with similar boiling points.
3.4 Biodiesel Properties
Biodiesel fuel quality depends upon composition of feedstock, production
process, storage, and handling. Biodiesel quality is evaluated through the
determination of chemical composition and physical properties of the fuel.
Contaminants and other minor components, due to incomplete reaction, are
the major issues in the quality of biodiesel (i.e., glycerol, mono, di, triglycerides, alcohol, catalysts, and FFA present in the biodiesel). Moreover, biodiesel composition could be changed during storage and handling. Biodiesel
can absorb water or undergoes oxidation during storage. Therefore, significance of these parameters and their analytical or engine test methods
are addressed in standards. Each country has its own fuel quality testing methods and standards to specify the properties of the fuel. Here the