Metal speciations on particulate matter and volatile organic compounds from external oil combustion boilers

Thirty-two oil boilers were studied for the emissions of particulate, metals and volatile organic compounds (VOCs) from stack exhaust. Results of the sums of fourteen metals in particulate are 3.5-23 mg/L oil. Emission factors of particulate are 0.09-6.53 g/L, and sums of seventeen VOCs are 0.1 mg/L oil. These boilers can be divided into three groups of stream generation capacity (> 30, 10-30, < 10 ton/hour); the mean value of particulate emission factors from small boiler is 1.7 g/L oil, which is significantly higher than those of medium (0.9 g/L oil) and large capacity boiler (0.7 g/L oil). In addition, emission factors of metal content for these three groups of boilers are essentially the same, due to the same oil constituents consumed in boilers. Experimental results also indicate that the emission characteristics of particulate slightly depend on the steam production rate and operation loading of boilers. However, VOC emission is not a problem for oil-boiler stacks.