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| News & Events |
Management Staff Required
Premier Group of Companies Islamabad requires the following management staff:-
General Manager for Distillery at D.I. Khan
Bsc Chemical Engineer having 15-20 years of experience at latest Ethanol plant, installation experience will be preferred.
General Manager-Rice Processing Unit
Services are required of an individual having 30 years diversified experience of management, establishment and running of a most modern Rice Processing Plant.
Candidates who fulfill the above may apply with a recent photograph not later than February 28, 2012 Email : psmisl@premiergrouppk.com
The Group has nationwide industrial and trading ventures in each province backed by a supporting network of offices in the business areas of Mardan, Lahore, Rawalpindi, Islamabad, Karachi.
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| Functionality |
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Processing
Traditionally, sugarcane processing requires two stages. Mills extract raw sugar from freshly harvested cane, and sometimes bleach it to make "mill white" sugar for local consumption. Sugar refineries, often located nearer to consumers in North America, Europe, and Japan, then produce refined white sugar, which is 99 percent sucrose. These two stages are slowly merging. Increasing affluence in the sugar-producing tropics increased demand for refined sugar products, driving a trend toward combined milling and refining. |
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Milling
Small rail networks and trucks are common methods of transporting cane to a mill. Newly arrived cane is tested for sugar content and trash percentage.
The mill washes, chops, and uses revolving knives to shred the cane. Shredded cane is repeatedly mixed with water and crushed between rollers in the milling tandem; the collected juices contain 10-15 percent sucrose. |
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Boiling |
| The syrup is placed into a very large pan for
boiling, the last stage. In the pan even more water is boiled off
until conditions are right for sugar crystals to grow. You may have
done something like this at school but probably not with sugar because
it is difficult to get the crystals to grow well. In the factory the
workers usually have to throw in some sugar dust to initiate crystal
formation. Once the crystals have grown the resulting mixture of crystals
and mother liquor is spun in centrifuges to separate the two, rather
like washing is spin dried. |
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Further processing
The cane juice is next mixed with lime to adjust its pH to 7. This mixing arrests sucrose's decay into glucose and fructose, and precipitates some impurities. The mixture then sits, allowing the lime and other suspended solids to settle. The clarified juice is concentrated in a multiple-effect evaporator to make a syrup of about 60 percent sucrose by weight. This syrup is further concentrated under vacuum until it becomes supersaturated, and then seeded with fine sugar crystals. A batch type sugar centrifuge separates the sugar crystals from the mother liquor. These centrifugals have a capacity of up to 2,200 kg per cycle. [1] The sugar from the centrifuges is dried and cooled and then stored in a silo or directly packed into bags for shipment.
The mother liquor from the first crystallization step (A-product) is again crystallized in vacuum pans and then passed through conitunuos sugar centrifugals. The mother-liquor is again crystallized in vacuum pans. Due to the low purity the evapo-crystallization alone is not sufficient to exhaust molasses, and so the so-called massecuite (French for “boild mass”) is passed through cooling crystallizers until a temperature of approx. 45°C is reached. Then the massecuite is re-heated in order to reduce its viscosity and then purged in the C-produced centrifugals. The run-off from the C-centrifugals is called molasses.
The spun-off sugar from the B-product and C-product centrifugals is re-melted, filtered and added to the syrup coming from the evaporator station.
Raw sugar is yellow to brown. Bubbling sulfur dioxide through the cane juice before evaporation bleaches many color-forming impurities into colorless ones. This sulfitation produces sugar known as "mill white", "plantation white", and "crystal sugar". Such sugar is the most commonly consumed in sugarcane-producing countries. |
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