Lynne Wong's PhD thesis

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and eventually to 10 US cents/lb, the generation of as much electricity as possible from
bagasse, the running of sugar factories for 7 days a week for up to 150 days, increased effort
to market specialty sugars, the review of new technologies such as molasses desugarisation,
dry cane cleaning to recover trash prior to cane crushing, improvement of sugar recovery
from cane, energy and water economy, and the production of co-products such as ethanol
and rhum agricole, a high value-added product produced from cane juice.
This thesis examines the effect of extraneous matter on sugar recovery and investigates the
avenues which could lead to the improvement of sugar recovery from cane. In order to
place this work in context, a brief description of the Mauritian raw sugar manufacturing
practices is presented in the next section. The meaning of terms associated with sugar
processing is given in the section entitled “Glossary of Terms”.
1.2 RAW SUGAR MANUFACTURING PROCESS IN MAURITIUS
The raw sugar manufacturing process in Mauritius is outlined in the flow-diagram shown
in Fig 1.2. The description of general practices in sugar processing is extracted from Chen
and Chou (1993). No attempt will be made to indicate the number, type and capacity of
each equipment used. For these details, see Kong Win Chang and Wong Sak Hoi (1999)
who have compiled the plant data of Mauritian sugar factories.
1.2.1 Cane harvest
In the early 1970s, almost all the cane stalks in Mauritius were stripped of all the
extraneous materials before being manually harvested and loaded. In 1975, due to the
shortage of manpower in the agricultural sector, grab loading of manually harvested cane
was resorted to, and represented 60% of the cane production in 1996. Since 1988,
mechanical harvesters were introduced and cane harvested by chopper harvester increased
steadily. It represented 16.7, 21.6, 24.3, 27.3, 28.6 and 32.3% of the total cane harvested
from 2001 – 2006 (Anon., 2001b; Anon., 2002a; Anon., 2003; Anon., 2004; Anon., 2005a
and Anon., 2006) respectively. Whole-stalk harvested cane represented only about 1% of
the machine-harvested cane in the early 2000s. The trend was towards green cane
harvesting, it increased from 67% of the cane mass harvested in 2002 to 72, 76 and 85% in
2003, 2004 and 2005 respectively.
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