Process Design 3 (118, 800 ton/annum butanol) was the only
profitable model for the economic conditions as tested in this
study and had the lowest TPCC of $ 187 million. However process
design must not only consider the profit, but also the risks for
the investor. Although some models may be profitable in certain
economic conditions, the cost of production and of capital expenditure
must also be considered, seeing that this can be a hurdle
for investors. For example of all the designs in Process Route 1, Process
Design 1.3 was the most profitable, but also has the highest
TPCC ($532 million). Similarly, when comparing Process Designs
1.2 and 2, the higher investment cost associated with LLE should
be weighed against the advantages (e.g. reduction in energy
requirements) of this process route. A large capital investment
prior to production will greatly reduce the number of possible
investors and effectively exclude financially weak consortia, a position
which is worsened by the increased risk associated with
new and innovative processes [23]. Major reductions in investment
costs (as for Process Design 3) will help improve process economics
and investment attractiveness.