Page 140 - Sustainability in the Process Industry Integration and Optimization

Ma s s I n t e g r a t i o n 117

Load Load
Sink composite
Sink composite
Pinch point Pinch point
Source
composite
Source
composite
Impure fresh
locus
Flowrate Flowrate
Minimum Maximum Minimum waste Minimum Maximum Minimum waste
fresh source recovery discharge fresh source recovery discharge
(a) (b)
FIGURE 5.3 MRPD for (a) pure fresh resource and (b) impure fresh resource.

source CC represents the minimum feed needed for fresh resources
(to be purchased); the region where the source CC extends to
the right of the sink CC represents the minimum waste discharge
from the network (for final treatment before releasing into the
environment).
Both the minimum fresh resources needed and the minimum
waste generated by the network are network resource targets, and
they are determined before the recovery network is designed. In the
next section, the MRPD is used to establish flow-rate targets for a
case study in the production of fruit juice.

5.5 MRPD Applied to Fruit Juice Case Study

Table 5.3 shows the limiting water data for a case study involving
the production of fruit juice (Almató, Espuña, and Puigjaner, 1999;
Li and Chang, 2006). The water amounts are expressed in cubic
meters (m ) per each batch. There is a start time (t ) and an end time
S
3
T
(t ) for each water sink and source. Prior to water recovery, freshwater
S
T
SKj F C j t t SRi F C i t S i t
T
i
SKi
SKj
j
j
[m ] [ppm] [h] [h] [m ] [ppm] [h] [h]
3
3
SK1 20 0 0.5 2.5 SR1 20 5 2.5 4.5
SK2 20 6 5.0 7.0 SR2 20 14 7.0 9.0
SK3 20 15 9.5 11.5 SR3 20 20 11.5 13.5
SK4 16 5 17.0 19.0 SR4 8 25 17.0 19.0
SK5 20 7 6.0 8.0 SR5 16 10 10.5 14.5
TABLE 5.3 Fruit Juice Production: Limiting Water Data