Cane field residues as supplementary fuel
| MSI08P4317 | |
| Deepchand, K. Lau Ah Wing, A. F. | |
| Cane field residues as supplementary fuel | |
| ISSCT Process Workshop: Green cane impact on sugar processing, Saint Denis, Réunion Island, 20 to 23 October 2008 - Program | |
| book chapter | |
| 2008 | |
| p. 15-16 | |
| Abstract only | |
| En | |
| En | |
| Cane field residues (CFR) consists of the dry cane trash and the green leaves left after harvest which lasts for around 6 months of the year (June to Nov/Dec). The CFR confers a certain number of agronomic advantages such as soil moisture conservation in dry areas, control of soil erosion and maintenance of soil organic matter. But it also imparts a number of disadvantages in that it harbours pest and affects cane regrowth especially in areas with high rainfall. In an original approach, investment was made in dry cane cleaning plant with a capacity of 150 tonnes of whole cane per hour and operated next to a sugar factory. The concept was to reduce sugar loss in bagasse and minimize sugar manufacture difficulties due to the CFR adhering/brought together with cane while at the same time targeting in the long term additional CFR recovery to increase fuel availability for power plants and thus displace coal. Difficulties were encountered in continuous operation of the plant due to a lack of a constant flo0w of cane and of an inefficient separation of the trash from the long cane. Subsequently some modifications were made to the plant but it could not run beyond 90 t/h, although an improvement in the separation process was noted. An alternative approach of using CFR (which normally contains around 25 per cent moisture depending on climatic conditions prevailing at harvest and in the subsequent days) is around 15 t/ha. The project aims at collecting up to 50 per cent of the CFR from the fields under ratoon crop and almost all the CFR from fields which are to be replanted after, 7-8 year crop cycle. Whereas equipment for collection (windrowing and baling - square or cylindrical) and transport are available for industrial applications, those for debaling/shredding have still to be identified or developed for such applications. The emphasis on current R&D has thus been laid on this particular aspect. Analysis of naturally dried CFR has revealed that it has a moisture content varying between 9 and 11 per cent. Its calorific value at 10 per cent moisture is around 15000 kJ/kg. Industrial scale trials using existing conventional mills have shown that such naturally dried CFR can conveniently be burnt in existing boilers. However in view of the fact that the naturally dried CFR has a relatively higher ash content (8 percent) compared to bagasse (2.5 per cent) it is proposed that it will, after preparation, be mixed with bagasse in a proportion of up to 25 per cent. Preliminary estimates indicates that if 30 per cent of the CFR are collected, prepared and mixed with bagasse from an annual cane production of 5.0 million tonnes of cane, it can potentially generate 250 GWh of electricity. In so doing this will replace 150 000 t of coal and avoid the generation of 400 000 t CO2 and 30 000 t of coal ash. In monetary terms, the foreign exchange saved will be US $ 32 million assuming a coal price of US$ 200/t as projected for the near future. | |
| cane field residues sugarcane residues boilers fuel green leaves trash energy | |
| Mauritius | |
| Cane sugar manufacture | |
| Byproducts utilization: Sugarcane tops | |
| 2008-12-08 | |
| En | |
| LIB | |
| CAT | |
| ST |