Lynne Wong's PhD thesis

• From 1976 to 1980, when the proportion of mechanical loading increased from about
10% to 40%, the full impact of extraneous matter on mill extraction was felt, milling
work was greatly hampered, and mechanical time efficiency at this period dropped
steadily from 96% to 93%.
• From 1980 to 2004, there was an upward trend in mill extraction mainly due to the
investment by various factories on heavy duty shredders, new milling units and millfeeding
control. Carding drums have also recently started to replace knives in cane
preparation installations, and hot imbibition is being practised by certain factories since
the early 1990s.
It is evident from Fig 1.10 that sucrose lost in bagasse % sucrose in cane is the mirror
image of mill extraction. It is worth pointing out that since co-generation of electricity for
export to the national grid has become a priority for the Mauritian sugar industry, efforts to
improve the calorific value of bagasse by reducing its moisture content has resulted in
record low values of pol % bagasse (Fig 1.11) and sucrose lost in bagasse % sucrose in
cane, of 1.22 and 2.81 respectively in 2000 (Wong Sak Hoi, 2001), while imbibition %
fibre remained low at 225 compared to South Africa, where the industrial average of
imbibition % fibre was reported to be 348 in 2000 and 369 in 2004 (Anon., 2005b).
2.2
1.8
1.4
Pol % bagasse
1.0
1960 1965 1970 1975 1980 1985 1990 1995 2000
Figure 1.11. Changes in pol % bagasse from 1960-2004.
24