Environmental Engineering Reference
In-Depth Information
Table 5.2
Average energy and water consumption for the production
of a lager beer in a small brewery in northeast Italy.
Step of the process
Metric
Energy consumed per
liter of beer (MJ/l)
Water used per
liter of beer (l/l)
Malting
0.856
1.00
Wort production
0.951
1.45
Fermentation and
clarification
0.118
0.26
Packing
0.301
0.20
Auxiliary processes
1.240
4.10
Adapted from Cordella et al., 2008.
100%
1.4
97%
1.24
90%
1.2
88%
80%
1
0.951
70%
0.856
63%
60%
0.8
50%
0.6
40%
36%
30%
0.4
0.301
20%
0.2
0.118
10%
0%
0
Auxiliary
processes
Wort
production
Malting
Packing
Fermentation
and clarification
Figure 5.5
Pareto diagram for consumption of energy for the beer example constructed with data
presented in Table 5.2.
which is available in the quality management toolbox. A Pareto diagram is a bar graph
(plotted in descending order) in which the length of the bars represents frequency or any
other unit; and it is useful to identify the steps with greatest improvement potential. If the
steps in terms of energy expenditure are sorted from largest to smallest and then plotted as
bars, it is easy to visually identify the most significant from the marginal ones (left
y
-axis
in Fig. 5.5). In addition, by dividing the energy consumed at each step by the total energy
consumed (3.466 MJ/L) a graph with the cumulative energy can be drawn (right
y
-axis in
Fig. 5.5).
