BIOREFINERIES: INTEGRATION OF DIFFERENT TECHNOLOGIES - Biomass as a Sustainable Energy Source for the Future - page 496

15.6 Check the derivation of Equation (15.11) for the calculation of NPV i % taking

into account the value of the particular sum called the geometric progression
(also called geometric sequence).

15.7 Regarding Example 15.3, investigate the impact of the interest rate on NPV

and the sensitivity values. What can you conclude from this exercise?

15.8 A 200 ML/year producing corn-based ethanol production facility is

reported to have cost 80 million dollar in 2008. What would the investment
be now?

15.9 Carefully read the article of Haas et al. (2006), describing an economic

evaluation of a biodiesel production facility based on soybean oil. Use the
methodologies for estimating the investment presented in this chapter for the
case presented in the article. Can you comment on the differences?

15.10 A biorefinery process called has been presented in the recent past

(Kamm and Kamm, 2004). It is a biomass-based process route making use of
acid hydrolysis and dehydration subprocesses and esterification with ethanol
to ethyl levulinate (EL) (an ester of levulinic acid and ethanol). By-products
considered are power and formic acid (FA). The production of EL is 133 kt.
year −1 . The capital cost is 150 million US$ (consider linear depreciation in
10 years). Table 15.8 gives an overview of the prices of the raw materials
and by-products. In addition, the water supply costs are US$ 500,000/year.
Regarding labor, there are 17 operators per shift working at a salary of
US$ 20/h and two supervisors per shift working at a salary of US$ 24/h.
Assume an ROI of 15%. For other costs, take the guidelines given in this chap-
ter (Table 15.6).

“ Biofine ”

a. Calculate the cost and return price in US $ per tonne EL produced.
b. What is the price in US $ per GJ HHV? (hint: calculate the heat of
combustion of EL).
c. Is it possible to produce the required ethanol in the process itself?

TABLE 15.8 Overview of costs, yields of by-products, and material
amounts for the “Biofine” process
Raw material/utility/by-product Amount Price in US$

350 ktyear −1

40t −1

Feedstock

3.5 ktyear −1 100t −1

Sulfuric acid

0.5 ktyear −1 120t −1 Caustic soda

35 ktyear −1 350t −1

Ethanol

0.12 ktyear −1 1500t −1 Hydrogen

17.5 ktyear −1 35t −1 Ash disposal

60 MWh −1

Power exported 3.1 MW

38.5 ktyear −1 110t −1 Formic acid sold