1. Sugar Industry T.Y.B.Sc Sub:Environmental chemistry
Mr.S.S.Patole (Assist.prof.Chem)

2. Introduction Most sugars occur naturally in fruits and vegetables
Sugar is produced in 121 Countries and global production now exceeds 120 Million tons a year. Approximately 70% is produced from sugar cane, a very tall grass with big stems which is largely grown in the tropical countries. The remaining 30% is produced from sugar beet, a root crop resembling a large parsnip grown mostly in the temperate zones of the north.

5. The sugar industry, basis of operation
Maximum sugar content in sugar cane 15% and sugar beet 17%
Sugar is highly soluble in water
Water as “the universal solvent” is highly available and inexpensive
The industry exploits above facts to dissolve the sugar out of the vegetable matter

6. Raw material preparation
the raw material (cane or beets) enters the sugar mill straight from the fields
It is unloaded onto chutes belt conveyor
Raw material is washed using high pressure water jets
Wash water carrying soil, insecticides,.. is collected as wastewater stream

7. Sugar cane processing
6.1 Crushing: juice (sugar solution) is squeezed and collected.
Discuss:
design of the system
how to achieve maximum sugar extraction
the solid waste ( baggasse ) stream, what to do with it ?

8. Sugar cane processing
6.2. Clarification: removal of organic acids impurities by adding “milk of lime” (calcium hydroxide in water suspension). This is a neutralization process. Insoluble calcium compounds are precipitated. Boiling is required to enhance the reaction (and kills the bacteria that may be present)
6.3 Filtration: to separate the clear solution from the solid material.
Question: what to do with the solid material

9. Sugar cane processing
6.4. Evaporation: to thicken the sugar solution to the point where it can be taken to a crystallization unit.
Very Important: Study all details
6.5. Crystallization:

11. A note about the invention of multiple effect evaporators
Norbert Rillieux is little known today, but his invention, the Multiple Effect Evaporator under Vacuum, revolutionized sugar processing.
Rillieux, a free African American, patented his invention in the 1840s.
The basic design is still in use in sugar processing and other industries.
Rillieux utilized the latent heat produced from evaporating sugar cane juice by employing a series of three or four closed evaporating pans in which vapor was piped out of each pan to heat the juice in the next, with the vapors in the end going to a condenser. At the same time, pressure in the system was reduced by pumps, which created partial vacuums and lowered the boiling point of the liquid.

12. SIMPLIFIED FLOW DIAGRAM SUGAR CANE INDUSTRY