Calorific value of bagasse - an overview
| MSI02P3773 | |
| Wong Sak Hoi, L. | |
| Calorific value of bagasse - an overview | |
| ISSCT Engineering Workshop "Energy management in raw cane sugar factories", Berlin, 7-11 October 2002. | |
| Conference paper | |
| 2002 | |
| Abstract only | |
| En | |
| En | |
| Fuel values of bagasse had been found as early as the 1920's to be influenced principally by the moisture it contains, and to a much lesser extent, by its soluble solids content (Pritzelwitz van der Horst, 1927, and Hessey, 1937). As cane harvesting operation became mechanized, the ash level in bagasse was found equally important as its moisture content in contributing to the lowering of its calorific value (Seip, 1976, and Don et al, 1977). Nowadays, mill run bagasse has a gross calorific value (GCV) of about 9 000 - 10 000 kJ/kg, and a net calorific value (NCV) of about 7 000 - 8 000 kJ/kg, as compared to a GCV value of 19 605 kJ/kg in bone-dry, ash-free and Brix-free bagasse. As cane pith has a lower fuel value than cane fibre, comparison of fuel values of bagasse from different cane varieties therefore has to be on comparable plant age, and on the same basis of moisture, ash and soluble solids content. An improvement in the calorific value of bagasse can be achieved by reducing the ash content in cane through the supply of good quality cane and by reducing the moisture content of bagasse leaving the mills through the use of hot imbibition, pressure feeders, pressure chutes, and good mill settings. Due to the energy crisis in the 1970's, efforts have been concentrated in further reducing the moisture in bagasse by drying with waste heat from flue gases, with the advantages of increased boiler efficiency from about 65 percent to 70 percent, decreased stack particulate emission and bagasse saved for other uses. Furines (1976) first reported the operation of an industrial bagasse dryer of rotary drum type using boiler stack gases. Since then, bagasse dryers mainly of the rotary drum and flash types have been installed over the world in America, Brazil, Philippines, Australia, China, Cuba and India. Arrascaeta and Friedman (1987) compiled data of 14 such dryers installed up to 1987 with details of feed capacity, input and output moisture and the temperature of the flue gas used. Reports of bagasse drying with varying degree of success followed (Maranhao, 1986, Dixon & Jorgensen, 1988, Wang et al, 1990, Kinoshita, 1991). A drying process was patented in 1981, it involves flue gas drying of bagasse after its separation into coarse and fine particles. The former is shredded before mixing with the latter and extruded as pellets, which can be stored for year round use as boiler fuel (Bouvet and Suzor, 1980). Pilot pellet plants were installed in 1980's in Hawaii and Mauritius, but due to the high cost of maintenance, its production cost was uncompetitive compared to the price of fuel oil, and the plants ceased to operate. | |
| cane sugar calorific values bagasse flue gas drying rotary dryer flash dryer sugarcane byproducts energy | |
| MAURITIUS | |
| Cane sugar manufacture | |
| Sugarcane byproducts | |
| 2002-11-08 | |
| En | |
| Mauritius Sugar Industry Research Institute | |
| ST | |
| LIST | |
| ST |