| 摘要 |
Disclosed is a method and system for recovering energy from low-grade fuels such as industrial, municipal and agricultural waste, low-grade carbonaceous fuels such as lignite and similar solid fuels in which the fuel is comminuted into small particles and slurried in water. The alkali content of the slurry is adjusted to be at least about equal to the chemical equivalent of the halogen content of the slurry and, following pressurization of the slurry, it is heated sufficiently so that the substantial portion of chemically bound oxygen in the fuel separates therefrom as carbon dioxide, leaving a slurry including char particles and dissolved impurities such as halogen salts. The char particles are removed from the slurry and reslurried with just enough halogen-free water to provide the slurry with the needed viscosity to maximize the energy density thereof. The char particles are then reacted with air at a temperature below their ignition value to convert the fuel value of the low-grade fuel into thermal energy which is then further used, for example, to drive a turbine (253, 255, 257).
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