In the algal fuels combustion stage, the following guidelines
should be pursued:
1. Determine the type of engine (or other power generation
equipment) to be used and calculate their emissions by different methods, usually by database.
2. Specify the engine (or other power generation equipment)
running time.
3. Determine how much fuel would be consumed during
operation.
4. Determine exhaust emissions.
It should be noted that the distribution of the algal fuels is
often ignored in LCA analysis. The rationale behind this assumption is that this would be implemented for both fuels, i.e., fossilbased and biologically oriented fuels [31]. In another word, such
data do not have any particular relevance to algal fuel production
systems. In order to comply with the Renewable Energy Directive,
it should be assumed that the distance between algae refinery and
fuel distribution station is lower than 10 km. Accordingly, the
emissions related to transportation can be cut off. Under such
circumstances, the related emissions would amount to less than
1% to the total impact categories [31].
It is noteworthy that recovering processes in the algae cluster
will involve open and closed loop recovering, including recovering
where changes in the inherent properties may occur. Both reuse and
recovering of products will be included in the LCA.
5.2 Data Allocation
Through allocation, the environmental burdens associated with
upstream activities should be distributed among all the
co-products of multi-output processes. It should be noted that
there are generally four major choices for value-based allocation
as follows [26]:
1. Null allocation: Using this approach, it is assumed that the
main product is associated with the entire energy requirements,
whereas the co-products are attributed with null energy
requirements.
2. Economic allocation or market value: Based on this approach
the distribution of the energy requirements is performed
accordingly to the economic value of each product.
3. Energy content or mass allocation: Herein, the basis for the
distribution of the energy requirements is a number of physical
properties of the products such as mass, calorific value, among
others.
4. System expansion, displacement, or substitution method: In
this approach, the expanded portion of the system, i.e., the
Life Cycle Analysis
133
should be pursued:
1. Determine the type of engine (or other power generation
equipment) to be used and calculate their emissions by different methods, usually by database.
2. Specify the engine (or other power generation equipment)
running time.
3. Determine how much fuel would be consumed during
operation.
4. Determine exhaust emissions.
It should be noted that the distribution of the algal fuels is
often ignored in LCA analysis. The rationale behind this assumption is that this would be implemented for both fuels, i.e., fossilbased and biologically oriented fuels [31]. In another word, such
data do not have any particular relevance to algal fuel production
systems. In order to comply with the Renewable Energy Directive,
it should be assumed that the distance between algae refinery and
fuel distribution station is lower than 10 km. Accordingly, the
emissions related to transportation can be cut off. Under such
circumstances, the related emissions would amount to less than
1% to the total impact categories [31].
It is noteworthy that recovering processes in the algae cluster
will involve open and closed loop recovering, including recovering
where changes in the inherent properties may occur. Both reuse and
recovering of products will be included in the LCA.
5.2 Data Allocation
Through allocation, the environmental burdens associated with
upstream activities should be distributed among all the
co-products of multi-output processes. It should be noted that
there are generally four major choices for value-based allocation
as follows [26]:
1. Null allocation: Using this approach, it is assumed that the
main product is associated with the entire energy requirements,
whereas the co-products are attributed with null energy
requirements.
2. Economic allocation or market value: Based on this approach
the distribution of the energy requirements is performed
accordingly to the economic value of each product.
3. Energy content or mass allocation: Herein, the basis for the
distribution of the energy requirements is a number of physical
properties of the products such as mass, calorific value, among
others.
4. System expansion, displacement, or substitution method: In
this approach, the expanded portion of the system, i.e., the
Life Cycle Analysis
133