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close this bookRenewable biological systems for alternative sustainable energy production. (FAO Agricultural Services Bulletin - 128) (1997)
close this folderChapter 3 - Production of fuel alcohol from cellulosic biomass
View the document3.1 Introduction
Open this folder and view contents3.2 Cellulase production
Open this folder and view contents3.3 Saccharification of cellulosic waste materials
Open this folder and view contents3.4 Use of immobilized yeast cells in alcohol fermentation's
Open this folder and view contents3.5 Alcohol production using an integrated pilot plant
View the document3.6 Feasibility study
View the document3.7 Conclusion
View the documentReferences

3.6 Feasibility study

In evaluating the economy of the system employed in the integrated pilot plant, the cost and method of collecting raw biomass material must be considered. From the viewpoint of reducing the burden of biomass collection, we examined the possibility of producing fuel alcohol at a site adjacent to a cane sugar production plant. Production was evaluated based on the unit processes demonstrated in the bench-scale plant.

A cane sugar plant at Mackay, situated on the east coast of Australia, was selected as the site. The scale of the plant is as follows:

Sugar cane processed

8000 (thousand tons/year)

Production of sugar

1000

Generation of bagasse

2000

Generation of molasses

200

Alcohol production was hypothetically established on a model scale at 72,000 kL/year (alcohol concentration: 99.5%), and was evaluated both with and without the use of a highly efficient bagasse boiler.


Figure 3.24 - Plot plan of an alcohol production plant

Table 3-11 Alcohol Production Costs (yen/litre) Based on Bagasse to Molasses Ratios

Bagasse/molasses ratio

With bagasse boiler

Without bagasse boiler

100/0

119.64

134.47

72/28

102.99

114.03

50/50

92.57

100.03

Table 3-12 Constitution of Costs at A Bagasse to Molasses Ratio of 72:28

Cost

With bagasse boiler

Without bagasse boiler


Raw materials

8.50

23.21

Variable cost

Chemicals

27.74

27.74


Service

10.18

10.18

Fixed cost

Equipment

39.38

39.38


Labor-fixed cost

12.85

9.18

Transportation

4.34

4.34

Total

102.99

114.03

From the plot plan of a hypothetical production plant shown in Fig. 3-24, a potential alcohol production plant would require an area of 300 m x 600 m = 1.8 x l0 m, including a stock yard. Table 3-11 shows the total cost in terms of the ratio of bagasse to molasses, while Table 3-12 gives the cost breakdown for a bagasse to molasses ratio of 72:28.