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3.1 MATERIAL CASCADE PINCH ANALYSIS

Material pinch analysis is an analysis whereby it is used for water saving and reduce

wastewater from its process. The analysis is sing a mass integration. In this context, the

material reuse is defined as effluent from one process unit is channelled to another unit and

does not re-enter the unit where it has been previously used; while recycle allows the effluent

to re-enter the unit where it has been previously used. When the maximum potential for direct

reuse or recycle is exhausted, the effluent may be sent for regeneration in an interception

unit.

The first step to do pinch analysis is to tabulate a table of water limiting data. In this

data, we can define how water that is consumed in the process whilst water that producedafter process is done. Table 3.1 and 3.2 show the water limiting data parameter for water

source and water sinks. Water source is defined as unit that produce water while water sinks

is unit that require water feed.

Table 3.1 Water sinks data limiting parameter

Water Sinks Flowrate Cheese composition(stream) (kg/s) (ppm)

Raw Water 5.39 0

Pasteurization 1.2 0

Washing 3.65 1.5

Cooling in Cheese Vats 0.56 0

Table 3.2 Water source data limiting parameter

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Water Sources Flowrate Cheese composition

(stream) (kg/s) (ppm)

Pasteurization 1.2 0

Cooling in Cheese Vats 0.56 0.5

Washing 3.55 1.25Wastewater 4.56 3.75

Water in Product 0.23 0.5

Material recovery pinch diagram can then be plotted into a diagram. By using

algebraic approach and calculate all the impurities load to do pinch, a pinch composition is

found at the composition of 1.25 ppm, which represents the most constrained area where

maximum recovery can be achieved.

C Total Fj Total Fi Total (Fj - Fi) Fcumulative m Total m

(ppm) (kg/s) (kg/s) (kg/s) (kg/s) (mg/s) (mg/s)

Ffw = 3.338

0 1.2 7.15 5.95 9.288 -19.43 -19.43

0.5 0.79 -0.79 8.498 26.3 6.87

1.25 3.55 -3.55 4.948 -6.87 0

1.5 3.65 3.65 8.598 -31 -31

3.75 4.56 -4.56 4.038 39.23 8.23

Fww = 4.038

Figure 3.1 shows that an amount 3.55 kg/s can be recovered to minimise the water usage. By

using this method, it can shows that amount of water to be feed is 3.338 kg/s, while the

wastewater produced is 4.038 kg/s. But, the amount of water to be recovered is large, 3.55

kg/s.

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0

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0 2 4 6 8 10 12

Impurityload(kg/s)

Flowrate, kg/s

Material Recovery Pinch Diagram

sink composite curve source composite curve

pinch

FFW = 3.34 FREC = 3.55 FWW = 4.038