Mill Material Balance
C H A P TE TE R I I
RAW MATERIAL COMPOSITION
Before beginning to know how to calculate the complete mill material balance, let’s have a look first to the composition of sugar cane as the raw material for the milling. James E. Irvine3) defined the composition of sugar cane into 2 (two) main groups: §
Water, which occupies 73-76%.
§
Dry matters, which occupies 24-27%.
The dry matters itself consist of dilatable portion 10-16% and non-dilatable portion, that is fiber amounting to 11-16%. Because the dilatable dry matter inhabits the cane juice, hence the cane juice is a mixture of water and the dilatable dry matters. In general the dilatable dry matters are: §
§
§
Sugars, consisting of: - saccharose (sucrose),
Salts, consisting of:
70-88%
- glucose,
2-4%
- fructose,
2-4%
- non-organic acids,
1,5-4,5%
- organic acids,
1,0-3,0%
Organic acids, consisting of: - carboxylic acids - ammoniac acids
§
Another organic organic matters, non-sugar: - protein, starch, gums, - wax, fats, etc.
§
Minerals, such as:
- potassium, sulfate, chloride, calcium, - magnesium, silica, phosphate, iron, - carbonate and others. others.
Based upon the technical approach above, all the materials could be grouped only into the following descriptions to simplify and matters constitutes the sugar cane used in the calculation of a mill material balance. We know that the raw material for the milling is sugar cane. As the result of the milling we obtain juice as the extracted matter and bagasse as the residue. 2)
Technically the composition of those materials can be grouped into the followings followings : 3) 2)
James E. Irvine, Mead-Chen, Cane Sugar Sugar Handbook - Chapter 2. Tenth Edition, 1977. See C.R. Murry & J.E. Holt, The Mechanics of Crushing Sugar Cane, 1967.
Raw Material Composition
II-1
Mill Material Balance
•
Cane, as the raw material is considered to consist of juice and fiber.
•
Juice, as the result of extraction, also contain in cane and bagasse, is considered to consist of water and Brix.
•
Bagasse, as the milling residue, is considered to consist of juice and fiber.
Because juice is considered to consist of water and Brix as mentioned above, hence: •
Bagasse is also considered to consist of water, Brix and fiber.
And then we knew also: •
Dry matter in bagasse, which considered consisting of fiber and Brix.
Now therefore: •
Bagasse is also considered to consist of water and dry matter.
Furthermore it’s known: •
Water content in bagasse, which is normally called moisture.
•
Brix free cane water in this regard is not consisting.
Raw Material Composition
II-2
