A study of treatment methods to improve the fuel characteristics of sugarcane variety B52298 was conducted. Two parent materials, whole cane (WC) and stripped cane (SC), were included in the study. The whole cane material was subjected to three treatments: (1) no treatment, WC-U; (2) a single milling, WC-M; and (3) an initial milling followed by leaching and a secondary milling, WC-MLM. Treatments (1) through (3) are in order of increasing severity. The stripped cane material was subjected to treatment (3) and designated as SC-MLM. Regardless of parent material, milling produced moisture contents of similar to50% wet basis and fiber bulk densities of similar to97 kg m(-3) in the treated fuels and produced a shift in particle distributions toward smaller sizes. Geometric mean diameters (by weight) of the WC-U, WC-M, WC-MLM, and SC-MLM materials were 2.3, 1.8, 1.3, and 1.3 mm, respectively. Ash generated from the fuel was reduced by roughly 1% (absolute) for each milling operation, resulting in reductions of similar to2% for the WC-MLM and SC-MLM treatments. Ash reduction was primarily due to the removal of K, Cl, and S by the treatment operations. Ash removal, in addition to reductions in the O content of the treated fuels, contributed to an increase in the energy content of the fuels from similar to17.6 MJ kg(-1) in the parent materials to 18.4 and 19.2 MJ kg(-1) for the WC-MLM and SC-MLM treatments, respectively. K, Cl, S, and N concentrations were all reduced in the fuel by the treatments. K comprised similar to1.3% of the parent materials and Cl accounted for 0.65% and 0.83% of dry matter for the whole cane and stripped cane parent materials, respectively. Reductions in K concentration relative to the parent materials for the WC-M, WC-MLM, and SC-MLM treatments were 50%, 86%, and 91%, respectively. Cl was reduced 62% by the WC-M treatment relative to the unprocessed whole cane, and removal was essentially complete for the two leached treatments. Sulfur in the two parent materials accounted for similar to0.22% of plant dry matter. Compared to the parent materials, the WC-M, WC-MLM, and SC-MLM treatments removed 36%, 82%, and 86% of the S, respectively. Nitrogen concentrations in the stripped cane and whole cane parent materials were 0.48% and 0.37%, respectively. Nitrogen reduction by the WC-M, WC-MLM, and SC-MLM treatments was 12%, 27%, and 57%, respectively. Ash deformation temperatures (oxidizing atmosphere) increased in the treated fuels compared to parent materials. Ash from the WC-MLM treatment did not attain the initial stage of deformation at the maximum test temperature, 1482degreesC. Ash of the WC-M and SC-MLM treatments became fluid at similar to1350degreesC. Experimentally determined fluid temperatures for the more severely treated fuels compared well with values predicted by a ternary phase diagram for the SiO2-K2O-CaO system. Slagging and fouling indices were computed for each of the fuel treatments. Values for WC-U and WC-M exceeded a benchmark of 0.34 kg (K2O+Na2O) GJ(-1) and would be expected to cause ash deposition in boiler use. Values for the WC-MLM and SC-MLM treatments were 0.13 and 0.08 kg (K2O+Na2O) GJ(-1), respectively, and are good candidates for boiler fuels. Concomitant reductions in S and Cl for these two fuels further reduce the likelihood of ash deposition, as well as improve environmental performance by reducing criteria and acid gas pollutant emissions. Mass balances for K and Cl were conducted for the treatment operations. Closure for the balances ranged from 112% to 122% over all treatments, and was viewed as validating the consistency of the results. (C) 2003 Elsevier Science B.V. All rights reserved.