Energy recycling is one of the promised technology to utilize solid wastes.The power generation process of Refuse Derived Fuel (RDF) produced by solid wastes is the suitable process for widely spread smaller sources, since RDF has enough properties for the storage and also for the transportation to an integrated power slation.In this paper, RDF production process and its properties are introduced.Then, the combustion properties of the single RDF particle are shown. Experimental results of the laboratory scale bubbling type fluidized bed combustor are introduced.Combustion test data of RDF by using the industrial 70.6t/h internal circulating type bubbling fluidized bed boiler are also shown and the behavior of DXNs is demonstrated.
A Increasing amount of waste plastics which causes serious pollution problem is a cheap and abundant source of chemicals and energy.The chemical recycling method, which converts waste plastics to useful hydrocarbons and monomers of the plastics, is recognized as a useful approach. The waste generated from factories is almost a specific resin, and the chemical recycle technology is being established for each plastics.However, the waste generated from household is mixture of the waste plastics.The technology developed for each plastics from factories is scarcely applicable for the waste from household.Here, a possible process, which enables to convert the mixture of waste plastics to fuels, is proposed.The key technologies of this process are; one is the usage of steam as a carrier gas, which accelerates the hydrolysis of oxygen-containing resin, the second the iron and Ni supporting REY zeolite catalysts, which show high activity in steam atmosphere, the third is a new type reactor with moved particles as a heat-medium for the pyrolysis.The utility of this process was examined by applying it to recover fuels from the mixture of poly-ethylene and poly (ethyleneterephthalate).
In recent years, recycling of the prastic wastes has increased in importance for the environmental conservation and energy recovery.It is nessecery to develop separation techniques of the plastics from the compound wastes which consisted of plastic and metals and these materials machanically coupled with each other.In this paper, we introduce a new separation technique of plastics from compound wastes using a molten salt developed by the authors.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 separation time was theoretically derived from a combination of the heating time and the deformation time.The theoretical result was found to agree well with the experimental result.
Composting involves the biological decomposition and stabilization of organic materials under conditions that allow the development of thermophilic temperatures as a result of biologically produced heat, and should yield a final product sufficiently stable for storage and application to land without adverse environmental effects.Aerobic composting, the decomposition of organic materials in the presence of oxygen, releases significantly high energy per weight of the organics decomposed.Thus, aerobic composting is suitable for production of a thermophilic temperature under which the decomposition rate of organics is high. Further, the process results in considerable drying of the final material;this is effective for reduction of subsequent handling costs, increases the attractiveness of compost for reuse, and pathogens and parasites that may be included in the original composting material are destroyed.The present article summarizes the special conditions of moisture and aeration required for effective aerobic composting. Further, the effects of the turning of the composting material on the rate of organic matter decomposition during the aerobic composting have been overviewed.A numerical model is then introduced in order to calculate the rate and the degree of organic matter decomposition, the temperature, and the moisture content under various aerating operations.The model was used to investigate the optimum conditions to obtain sufficiently dry compost.Calculations based on this model suggest that water can be eliminated most effectively when aeration is controlled such that the reactor is kept at its optimum reaction temperature;i.e., 60°C.
Immiscible lattice gas is one of the lattice gas automata methods to simulate phase separation phenomena.In the present paper, immiscible lattice gas model was applied to simulate the flow through complex obstacles simulating porous media in a debris bed.It was approved that the complex obstacles were successfully generated by the present method including the number of obstacles and grain size of obstacles by changing some control parameters.The simulating two-dimensional flow shows the flow concentration in specified flow channels.The simulating results of the flow through the porous media by the present method were compared with the Ergun's equation for the flow through porous media.It was clarified that the present results qualitatively agree with the Ergun's equation in the range of higher Reynolds number than 8.Furthermore, in order to check the applicability of the present method to the physical situation, the simulation results by the present method are compared with experimental results.The velocity distributions from the simulations shows good agreement with the experiment.It can be concluded that the present technique is useful to simulate flow through complex geometry like porous media.
Supercritical fluids will be promised as a powerful and available reaction media in 21th century's industry.In this paper properties of supercritical fluids as a reaction (crystallization) media and its applications for powder processing are described.