Analysis of potential RDF resources from solid waste and their energy values in the largest industrial city of Korea Trang T.T. Dong, Byeong-Kyu Lee * Department of Civil and Environmental Engineering, University of Ulsan, Ulsan 680-749, Republic of Korea article info Article history: Accepted 13 November 2008 Available online 10 January 2009 abstract The production potential of refuse derived fuel (RDF) in the largest industrial city of Korea is discussed. The purpose of this study is to evaluate the energy potential of the RDF obtained from utilizing combus- tible solid waste as a fuel resource. The total amount of generated solid waste in the industrial city was more than 3.3 million tonnes, which is equivalent to 3.0 tonnes per capita in a single year. The highest amount of solid waste was generated in the city district with the largest population and the biggest pet- rochemical industrial complex (IC) in Korea. Industrial waste accounted for 89% of the total amount of the solid waste in the city. Potential RDF resources based on combustible solid wastes including wastepaper, wood, rubber, plastic, synthetic resins and industrial sludge were identified. The amount of combustible solid waste that can be used to produce RDF was 635,552 tonnes/yr, consisting of three types of RDF: 116,083 tonnes/yr of RDF-MS (RDF from municipal solid waste); 146,621 tonnes/yr of RDF-IMC (RDF from industrial, municipal and construction wastes); and 372,848 tonnes/yr of RDF-IS (RDF from indus- trial sludge). The total obtainable energy value from the RDF resources in the industrial city was more than 2,240,000 Â 10 6 kcal/yr, with the following proportions: RDF-MS of 25.6%, RDF-IMC of 43.5%, and RDF-IS of 30.9%. If 50% or 100% of the RDF resources are utilized as fuel resources, the industrial city can save approximately 17.6% and 35.2%, respectively, of the current total disposal costs. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction The increase of the quality of human life as well as rapid eco- nomic development and industry have created a huge volume of solid waste (SW), which has become one of the most critical cur- rent environmental problems. Many methods have successfully been used to dispose of different types of solid waste. Each disposal method has its advantages and disadvantages (Lee et al., 2002). Landfilling is a long-standing disposal option; however, it is not a very suitable disposal method because of leachate problems and scarce available space. Bioremediation is an approach which decomposes waste; however, it is only suitable for biodegradable waste. Dumping into the ocean is one of the cheapest disposal methods but also the most harmful to the marine environment. Therefore, dumping is no longer allowed in many countries (US EPA, 1988; Copeland, 1999). Thermal treatment by using incinera- tion technology has been proven to be an attractive method of waste disposal for many years (Chang et al., 1998). Incineration has been widely used because it is capable of reducing approxi- mately 90% of the original volume and 75% of original weight of SW and can provide energy recovery (Cheremisinoff and Morresi, 1976; Kusar et al., 2003). However, incineration has the drawbacks of producing ash and hazardous air pollutants such as dioxins and furans (Sell, 1992; Lee et al., 2004). Much of the solid waste can be transformed into useful prod- ucts, and thus the proportion of solid waste that is being recycled, reused and recovered is increasing. Many countries are suffering from waste disposal problems and fuel shortages. To solve both waste and energy problems simultaneously, the refuse derived fuel (RDF) approach has been utilized in many countries (Cheremisinoff and Morresi, 1976; de Vries and Pfeiffer, 2005; Fu et al., 2005; Lin et al., 2002; Morris and Walheim, 1998). Before being incinerated, solid waste is classified based on combustible capacity and then materials with a high calorific content are used to produce RDF. The major advantages of the RDF approach are a large reduction of the volume and an effective utilization of SW available for a reusable energy form (EC-DGE, 2003). Korea and other countries are faced with a shortage of available landfill space and difficulties in constructing new landfills due to the not-in-my back yard (NIMBY) syndrome. Additionally, Korea is a country which lacks natural resources for fuel or energy. There- fore, the RDF approach is a potential solid waste treatment option which is suitable for Korea. The metropolitan city of Ulsan, the largest industrial city in Korea, has many large industrial com- plexes (IC) such as petrochemical, non-ferrous metal, and me- chanic and shipbuilding. Thus it generates a large amount of solid waste from both urban and industrial areas. The current ma- jor disposal methods of SW are landfilling, incineration, recycling, 0956-053X/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2008.11.022 * Corresponding author. Tel.: +82 52 259 2864; fax: +82 52 259 2629. E-mail address: bklee@ulsan.ac.kr (B.-K. Lee). Waste Management 29 (2009) 1725–1731 Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman