PBDE Emissions during the Start-up Procedure of an Industrial Waste Incinerator by the Co-Combustion of Waste Cooking Oil and Diesel Fuel

ABSTRACT

This study examined the effect of using waste cooking oil (WCO) as an alternative of diesel on PBDE emissions during the start-up of an industrial waste incinerator (IWI). The co-combustions were designed with 0, 40, and 60% WCO injection and become D100, W40D60, and W60D40 multi-fuel combustions. The flue gas was sampled during 4 temperature stages of the furnace: Stage A (< 200°C), Stage B (200–450°C), Stage C (580–700°C), and Stage D (> 850°C). The highest PBDE level was found in Stage A and sharply declined in Stage B by using diesel. The reduction of total PBDE was a competitive result between residue releasing and thermal decomposition in Stage B. The WCO were found to slightly increased the PBDE emissions during the Stage C and D, which provided the suitable temperature for PBDE formation (600–800°C). Therefore, the viscosity became an important control factor when the WCO were utilized as an alternative fuel in IWI operation. The accumulated PBDE emissions during the start-up procedure were 1,099, 1,253, and 1,207 µg by using D100, W40D60, and W60D40, respectively. Additionally, the annual PBDE emissions contributed by start-up procedures increased up to 4.60%, 5.47%, and 5.20% by three fuel combinations, respectively, if the IWI restarted once per month, and became a noticeable issue. Therefore, avoiding unnecessary start-ups was an essential criterion for IWI operation. The small increases (< 1%) of PBDE emissions by altering 40% and 60% diesel with WCO provided a useful information for WCO treatment. This new disposal for waste oil also created a good demonstration of Circular Economy. The overall life-cycle analysis was suggested to be investigated in the following research.