MSW source separation and REF production - experiences

When part of MSW is processed to REF - recovered fuel, the aim is to obtain an advantage in energy production. This target is reached in two ways: For REF advanced combustion technology can be applied that makes it possible to reach low emissions at lower costs and, secondly, to achieve higher efficiency in electricity production. MSW has traditionally been collected and handled in one mixed fraction, as there has been no incentive to separate different fractions, when MSW was dumped to a landfill or incinerated. However, the source-separation system and collection systems applied in Finland have a significant effect on the quality of the recovered energy fractions. Further, in REF production, most fuel properties of the recovered energy fraction can be improved. As generally known, MSW comprises three main fractions: household waste, commercial waste from shops, offices and companies, and also process waste from small enterprises. In many countries, the process waste from small enterprises is included in MSW, because it is collected together with the other MSW fractions. This fraction also contains some construction waste. Fuel properties of the combustible part of the above mentioned waste fractions are presented in Table 1. The values are long term mean values based on analyses carried out at VTT Processes. Figure 1 presents an estimate of the composition of the combustible part of the main waste fractions in the Helsinki area (Mäkinen et al. 2000:10).