To produce a heat insulator by curing with steam at low temperature, a new technology of using coal ash discharged from pressurized fluidized bed combustor (PFBC) was developed. Effects of various curing conditions on manufacturing of heat insulator were investigated. Results are summarized as: (1) the produced heat insulator mainly consists of calcium silicate hydrates, calcium aluminate sulfate and hemihydrate gypsum, (2) high quality heat insulators were able to manufactured under conditions of temperature 353 K, humidity 80%, curing time 24 hr, (3) the new insulator produced here shows better qualities than that of some commercial brick.
Previously, we reported the development of a new separation technique of plastics from compound wastes by using a high temperature molten salt as a separation medium, in which the basic characteristics of separation phenomena were investigated. In this report, a simple theoretical model was developed for predicting of the separation phenomena. The model includes both heating and deformation processes of the plastic. The heating process was analyzed as the boundary value problem of heat conduction involving with heat transfer, The flow of the fluidized plastic was described as a high viscosity flow driven by the buoyancy force. The deformation on the surface of the plastic was predicted theoretically. The deformation pattern was found to be in qualitatively agreement with the experimental data. Separation time was measured experimentally against the various thickness of plastic. Theoretical separation time was derived from a combination of the heating time and the deformation time, and was described as a function of plastic thickness. The theoretical model was found to agree well with the experimental result.
Experimental results of catalytic Pyrolysis of Taiheiyo coal in a powder-particle fluidized bed (PPFB) under hydrogen atmosphere were analyzed. The catalytic pyrolysis in PPFB was considered to occur in two steps, that is, the primary pyrolysis and the catalytic decomposition of the pyrolysis product. The reaction model for the catalytic decomposition was proposed. The experimental results of hydropyrolysis of coal with CoMo-B catalyst in PPFB were analyzed by using the reaction model under the assumption of a plug flow for gas and a perfect mixing for catalyst particles in the bed. Activation energy and frequency factor of each reaction rate constant were obtained from the experimental data. Calculated yields of light aromatic hydrocarbons and gaseous products approximately agreed with experimental ones. The calculation result can be used to predict yields of tar, light aromatic hydrocarbons and gaseous products for designing this type of catalytic pyrolysis reactor.