RDF processing

Unfortunately for the RDF industry, the first attempts at implementing an RDF processing system met with disappointment and failure. With no European technology to draw from, RDF processing evolved from experience and inspiration gained from the U.S. applications. In the earliest processes, the design called for all of the incoming waste to be shred-... 

The material losses of alternate RDF processing plants depend mainly on the sophistication and plant. This should depend upon economics if it is economically justified to recover more combustibles, it should be done. There is a limit to the investment and operating costs which can be justified to recover the last Calorie. The same applies to recovering aluminum and glass. At this date fuel energy is the valuable product ferrous metals have low economic value, aluminum recovery... 

Refuse-Derived Fuel (RDF) - A solid fuel produced by shredding municipal solid waste (MSW). Noncombustible materials such as glass and metals are generally removed prior to making RDF. The residual material Is sold as-ls or compressed into pellets, bricks, or logs. RDF processing facilities are typically located near a source of MSW, while the RDF combustion facility can be located elsewhere. Existing RDF facilities process between 100 and 3,000 tons per day. 

Incineration and, to a lesser extent, RDF processing, can have less stringent requirements for type and state of waste input, but there is still some need for sorting to eliminate potentially hazardous materials. 

Refuse-Derived Fuel. Many processing faciUties divert a portion of the material that is not recovered for recycling to waste-to-energy plants, also referred to as resource recovery faciUties, where the material is employed as fuel. The processes involved in the production of refuse-derived fuel (RDF) are outlined in Figure 4 (23). Nine different RDFs have been defined, as Hsted in Table 3 (24). There are several ways to prepare RDF-3, which is perhaps the most popular form and is the feed used in the preparation of densified refuse-derived fuel (d-RDF). AH forms of RDF are part of the broader set of waste-derived fuels (WDF), which includes various waste biomass, eg, from silvaculture or agriculture (see Fuels frombiomass Fuels fromwaste). 

Fig. 4. Typical sequence of unit processes for RDF production where A/C = air classification. Optional locations are indicated by surrounding dashed...

Fig. 7. Scheme demonstrating how MSW can be converted into energy by first processing MSW into refuse-derived fuel (RDF) (12). 

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). 

Simplified in process terms, RDF involves processing the incoming municipal solid waste (MSW) stream to remove a substantial portion of the noncombustible components, namely aluminum, ferrous, glass and dirt. Various sources list these components in the range as follows ... 

Rdf The characteristic size of the TiCi s, dy, is reduced by 45%. The 3-hr. yield is thereby increased by 53%, a very significant benefit to the process. Methods to achieve this kind of change are well worth investigation. 

Abstract Looking for the possibility of using Refused Derived Fuels (RDF) in the substitution of fossil fuels is one of the main subjects in the Waste to Energy aspect. Therefore this study has been taken in this direction. The influence of waste composition on RDF quality produced by Dry Stabilization Process (DSP) and the evaluation of C02 emission of this product were undertaken. 

Keywords Refused Derived Fuels (RDF), Dry Stabilization Process (DSP), Municipal Solid Waste (MSW), Waste composition, Waste amount, Heating value, Emission Factor (EF)... 

This study aims to look for the possibility of producing refuse-derived fuel (RDF) according to dry stabilization process (DSP) and investigates the possibility of substitution of fossil fuels by RDF. With that, this study tried to assess the risk of C02 emissions from RDF produced by MS W Hanoi, compared with C02 emissions from fossil fuels. 

RDF-2 Wastes processed to coarse particle size with or without magnetic metals... 

RDF-3 Shredded fuel derived from MSW has been processed to remove metal, glass,... 

RDF-4 Combustible waste processed into powder form 95 wt.% passing 10 mesh screen... 

RDF-6 Combustible waste processed into liquid fuel... 

As for ASTM, RDF-1 is the major form of RDF used worldwide RDF-5 is densified refuse-derived fuel (d-RDF). Waste can be processed to make fuel in solid, liquid, or gas phase. In the frame of this study, only solid RDF will be concerned, and it will be mentioned as RDF from here. 

Temperature is an important indicator in RDF producing process. The temperature in these three barrels was higher than atmospheric temperature, but there was not much difference. The barrel was put in the open air therefore, it might be affected much by the weather changes. 

In the final product, R2 still had higher water content than that in R1 and R3 in spite of in input material this factor of R2 was lower. May think, the percentage of biowaste plays a key role in reducing the water content. Low biowaste content may result in inefficient drying process, but if this component is high, it will cause low quality of RDF. 

In this study, waste was separated manually and composted without air pumping. Therefore, neither energy nor auxiliary fuels were needed. However, whenever RDF is produced in factory settlement, electricity and diesel are needed together with other supplement activities. For that system by using DSP method, separation, transportation, and other processes are required. Therefore, 93.8 kWh of electricity is needed for 1 ton of input waste operation [15]. 

Data for the calculation of N20 emission in pretreatment process was taken from references. The N20 emissions are converted to C02 equivalents by following formula (5). The average emission of N20 in RDF plant applying DSP method is considered 5.6 g/ton MSW, which result to the increasing of GHGs emission by 1.62 kg C02 eq./ton MSW [15],... 

Almost carbon (C) in waste is oxidized into C02 through combustion process. A small amount is converted into carbon monoxide (CO), but this is often ignored. According to IPCC 2006, only fossil C02 is accounted as GHG emission source, while C02 which is formed from C bio is considered neutral and not added to total GHGs emission. However, amount of C02 bio was still calculated for reference purpose. C02 emission in RDF utilization process (burning process) is calculated based on fossil carbon content of waste fractions by the following formula ... 

The result C02 emission from combustion process is shown in Table 11, assuming that average combustion efficiency in all cases is 97.5% [Hu(raw) > 10 MJ/kg RDF],... 

In the same way, N20 emission in pretreatment process was calculated, whereas N2O emission in this combustion step was taken from references for German waste, it is estimated to be 3.41 kg C02 eq./ton RDF (GWPN20 = 298) [15]. 

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