Cane trash

Use of bagasse (i.e. the dry pulp remaining after the juice has been extracted from sugar cane) and cane trash as fuels in a BIG-GT process. 

In the area of sugar cane harvesting, the objectives are to improve the equipment and procedures for recovering the cane trash, whilst also studying side effects such as decrease in the use of herbicides. A second objective is to make realistic assessments of the cane recovery potential, fuel quality and the associated cost. 

The independent mode is essentially an adaptation of the WBP project combined-cycle plant concept operating with bagasse and trash. In independent mode, for one BIG-GT module based on the LM 2500 gas turbine and a HRSG operating at 60 bar/500 C, a net electric output of 33 MWe, and a net electric efficiency of 40% can be achieved for bagasse but with cane trash, the efficiency on an LHV basis is 34 to 37%, the lowest value associated with a dry fuel during the off-season period when low level heat recovery in the dryer is no longer appropriate. 

After the first screening step, based on preliminary heat balances and engineering judgement, six systems were selected. In the calculations, it was assumed to have year-round production in the BIG-GT plant, cane trash would be mixed with bagasse and any steam in excess of the mill need would be used in a new condensing backpressure nirbogenerator at the appropriate pressure level. The results are shown in Table 3. 

According to data reported by Hardy (1944), a typical sugar-cane crop produced about 3,500 lb. of roots per acre in the upper 6-inch layer of soil. The cane trash had a weight of about 20,000 lb. Of course these values are greatly in excess of those for most crops grown in more northern regions. 

Mulching materials consisting of various kinds of plant materials have long been used by gardeners, fruit growers, nurserymen, and those interested in ornamental shrubs and flowering plants. These materials commonly include such materials as peat, manures, straw, cornstalks, corncobs, sugar-cane trash, leaves, peanut hulls, wood products, and various other kinds of litter. Since such materials must be applied to a depth of at least two inches if weeds are to be kept under control, it is obvious that they are too expensive (at least in terms of labor) for use as full mulches on field crops. 

Blair N (2000) Impact of cultivation and sugar-cane green trash management on carbon fractions and aggregate stability for a Chromic Luvisol in Queensland, Australia. Soil Till Res 55 183-191... 

Sugar cane, as cut, consists of the cane itself, the leaves and the tops. At present the tops, which contain on a dry basis about 44% carbohydrate, 7% protein, 32% fiber, 2% fats and 10% ash, are turned back into the ground. This procedure may, however, be wasteful. Fertilizers must be used, but it might be possible to extract other products from the cane tops before they are used for this purpose. To give one example, the tops may be fermented to yield alcohol. Lonkar and Rao have outlined a process whereby dry leaves ( trash ) can be converted into paperboard or wrapping paper, a process which could be applied on a scale such that a factory dealing with 9,000 tons of trash annually could turn out 3,000 tons of paperboard. 

Preparation of Cane for Milling. Because of the presence of adhering soil, rocks, and field trash, mechanically harvested cane usually must be washed before milling. In some carefully controlled situations, when the weather has been dry, washing can be eliminated. Washing systems range from a simple spraying with warm water on the carrier or cane table to an elaborate system... 

Waldheim, L., Morris, M., Leal M.R.L.V., (2001) Biomass power generation Sugar cane bagasse and trash. In this proceedings. 

Biomass Power Generation Sugar Cane Bagasse and Trash... 

Agronomic routes to green cane harvesting with trash recovery. 

Various cane harvesting and trash recovery procedures have been developed and evaluated, not only in relation to the economy of the recovery operation, but also in relation to the quality of the trash as well as weed control aspects. The potential for reduction in the emission of greenhouse gases by changing from traditional harvesting... 

Evaluation of sugar cane bagasse and trash availability and quality. 

This part focuses mainly on the trash, as the availability and quality of bagasse is already well understood. The studies will establish the theoretical quantity of trash available from normal and developed cane varieties, the amount that can realistically be recovered (taking into account also the impact of leaving trash in e field) and the fuel quality aspects of the trash. 

Whole cane harvesting loading and transporting cane and trash cleaning and trash recovery at the mill. 

Whole cane harvesting cane picked up, chopped and cleaned in the field transporting clean cane baling and transporting trash to the mill. 

The cane quality and the trash quantity recovered in practice, as well as the cost for its recovery, will be different for each scheme. The knowledge and experience... 

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