Biomedical Engineering Reference
In-Depth Information
5. Economic Evaluation
Marchetti and Errazu compared four types of processes. They determined that a two step
supercritical method was better technically and environmentally than more conventional
processes, but not economically. It was proposed that a one step supercritical process with a
propane co-solvent would be economically suitable. [45].
However, many studies indicated several issues must be highlighted:
•
The cost structure of bio-diesel production makes it so that its competitiveness
crucially depends on the price of the bio-mass feedstock and of the by-products
obtained.
•
Technological improvements may contribute to increase the market penetration of
bio-diesel, but a mature bio-diesel sector is conditioned by a stable and cheap supply
of feedstock.
•
The competitiveness of bio-diesel also depends on the evolution of the fossil diesel
prices.
•
These three parameters are highly volatile and difficult to predict. Policies to ensure
price stability should be endeavoured to favour a deeper penetration of bio-diesel
crops.
•
Bio-diesel is an energy carrier, whose manufacturing and production at industrial
scale is totally determined by non-energy policies, i.e. agriculture policy (and, in
particular, the set-aside schemes adopted), fiscal policy, etc.)
•
Bio-diesel blends, i.e. mixing bio-diesel and fossil diesel, are viable way to foster a
less carbonintensive automotive sector.
•
However, in the long run and considering the agricultural yields, bio-diesel is not
likely to supply a two-digit percentual share of the global road transport fuel needs.
•
The set aside policy is a valuable instrument to introduce bio-fuels in transport
market, but given the land area needed to cover the global demand, the competition
with food-production crops will principally impeach their massive market
penetration.
5.1. Economic Variables
Important factors for economic feasibility of a plant are raw material price, production
capacity, glycerol price, and capital cost. [20, 46] These will be discussed below.
5.2. Raw Material Price
Feedstock cost is often the major factor in biodiesel production. Capital cost is only 7%
of final product cost [11]. It is estimated that 88% of cost is feedstock [18]. Table 19 provides
a summary detailing the percentage of importance of certain factors in manufacturing cost in
the supercritical methanol method. Raw material cost is reduced by the ability to use
feedstock with high percentage of FFAs as in waste cooking oils and animal tallow such as in
the Mcgyan process and supercritical methanol method. At subcritical conditions, such as
