The effect of green cane on downstream factory processing.

There is a world-wide shift from burnt to green cane harvesting. In many countries, including the United States and South Africa, certain areas are changing to green cane harvesting due to public, tourism and environmental pressures against open field burning, increasing labour costs, and the potential use of sugarcane trash as biomass for the production of bio-products. While some countries have already converted to total green cane harvesting, of the 23 million tonnes of cane that is annually processed in South Africa, almost 85% is still burnt. Since the 1940s there have been factory trials all over the world on green cane processing but, due to the sheer magnitude of such trials, none have managed to shed much light on the effect on downstream processing beyond clarification. This paper reports on the effects of harvesting green billeted sugarcane compared to burnt billeted and/or whole-stalk sugarcane on factory front end processes and on downstream processing in a pilot plant. Pilot plant processing was done on samples collected from two factories situated in the Midlands area of South Africa. Sufficient cane of each treatment was harvested and processed to purge the extraction plant of other cane. Trash materials and mixed juice were collected and analysed. The effects of trash levels on prepared cane, bagasse and mixed juice are reported. Factory mixed juice (300 L) was transported to the SMRI in Durban and further processed in the SMRI pilot plant to clarified juice, syrup, A-massecuite, A-molasses, A-sugar, and affinated sugar. Various differences in physico-chemical parameters including colour and ash are presented.