Refuse derived fuel , combustion

J. L. Smith, Early and Current Systems Utilising Refuse Derived Fuels, Combustion Engineering Co., Windsor, Conn., 1986. 

Municipal Solid Waste. In the eady 1990s, the need to dispose of municipal soHd waste (MSW) ia U.S. cities has created a biofuels industry because there is Htde or no other recourse (107). Landfills and garbage dumps are being phased out ia many communities. Combustion of MSW, ie, mass-bum systems, and RDF, ie, refuse-derived fuel, has become an estabhshed waste disposal—energy recovery industry. 

Once a decision has been made to recover materials and/or energy, process flow sheets must be developed for the removal of the desired components, subject to predetermined materials specifications. A typical flow sheet for the recovery of specific components and the preparation of combustible materials for use as a fuel source is presented in Fig. 25-63. The light combustible materials are often identified as refuse-derived fuel (RDF). 

Combustion of plastics waste with energy recovery is discussed as one approach to the recycling and waste management of waste plastics. Their role in municipal solid waste combustion is examined, and the importance of refuse derived fuel pellets. Facts supporting the importance of waste to energy projects are reported, and details of some projects currently examining MSW combustion with energy recovery are detailed. 

Organic compounds in the various effluents from the efficient combustion of coal at power plants do not appear to be an environmental problem. This conclusion is based on interpretation of results obtained during a four-year study of samples of stack gas and fly, grate and stack ashes from the combustion of coal alone and of mixtures of coal and refuse-derived fuel. 

Because of this environmental concern, an extended study of the Ames power plant for generating electricity was begun in 1977. This study included all types of pollutants such as N0X, S0X, total suspended particles, fly ash, grate ash, and trace elements as well as the organic compounds from the combustion of coal alone and mixtures of coal and refuse derived fuel (RDF). The results in this report are confined to the organic compounds found in all of the... 

Characterization of Refuse-derived Fuel (RDF) Combustion Technology, Draft Report No. EPS... 

According to the principle of indirect heating, the pyrohtic gases are not diluted by nitrogen or by combustion products. Tables 10.26 and 10.27 give some examples of refuse-derived fuels obtained by pyrolysis of different waste streams [80]. 

The concentrations of TriCDTs, TeCDTs, and PeCDTs in soil and sediment samples, gas samples from waste incineration and aluminum smelting, ash from an aluminum smelting plant, a car shredder, and from combustion of wood chips, peat and refuse derived fuel, different effluents from a pulp and paper mill, and crab, carp, and lobster tissue samples, are presented in Table 1. 

Refuse-derived fuel i.e., the combustible fraction of municipal solid waste, from a Chicago facility. From a Chicago Metropolitan Sanitary District facility. 

A number of biomass fuels and refuse derived fuels (RDF) have been gasified and subsequently combusted in the Vamamo plant. The fuels cover a broad range of nitrogen content, from 0,1% in sawdust to 1% in wheat straw. 

The energy recovery efficiency of the ECO-FUEI II process is high by comparison with other alternate routes to combustion of Refuse-derived-fuels, for reasons which may not be so apparent. 

Although both are graded solid fuels of broadly similar bulk densities there are significant differences in respect of other properties. The densified refuse derived fuel has a lower calorific value, higher ash content and lower ash fusion temperature. The major differences are the much higher proportion of volatile matter in the dRDF coupled with a very much lower value for the fixed carbon. These differences are likely to be sufficient to render not only the combustion properties different, but also the deposition from the respective flue gases. 

All the temperatures for the coal ash are significantly higher than the corresponding temperatures for the refuse derived fuel. The reason for these differences is that the ash produced by the combustion of domestic refuse, is different in chemical composition from the ash associated with coal combustion. 

Guim, D., 1990, The combustion of densified refuse derived fuel in shell boilers. dRDF Workshop, Department of Energy (ETSU) and Glasgow District Council, Glasgow. 

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