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Show Results Toluene Tests Figure 3 illustrates the mass emissions of THC, CO and soot as a function of the mass of toluene fed into the kiln. Notice that soot increases with increasing toluene mass in both the pulsed and non-pulsed cases. The C O increases going from 80 to 100 g of toluene, but remains flat at higher masses in the non-pulsed case, and actually decreases in the pulsed cases. Hydrocarbons increase going from 80 to 100 g, but decrease at the higher mass case in both the pulsed and non-pulsed conditions. The decrease in T H C at the higher masses is consistent with the earlier results7, and is presumed that soot is preferentially formed during extremely large puffs. In fact, for this reason, past toluene work done by Linak et al.7 used soot alone as the surrogate indicator of puff magnitude when burning toluene. The decrease in C O at the high mass conditions is counter to intuition. The seeming decrease in total mass emissions of C O at the high mass case is possibly due to increased utilization of the remaining bulk oxygen. The most notable difference between the pulsed and the non-pulsed data is the marked decrease in the measured emissions of soot. There is approximately a 5 0 % reduction in the mass emissions of soot at the 80 and 100 g cases, with approximately a 3 0 % reduction at the 150 g case. This phenomena could be the result of one of two effects: either the formation of soot is being inhibited due to changes in flow characteristics and mixing patterns caused by the high amplitude acoustic waves in the environment where soot forms, or the already formed soot and semivolatile organic material is being pyrolyzed at a faster rate into C O and T H C . Any unoxidized waste material must either remain as toluene (which is detected on the FID in the T H C analyzer) or is converted to soot or C O or another FID detectable hydrocarbon. Figure 4 illustrates the Carbon Penetration (CP) for each of the investigated cases. The data shows that the pulsations reduced the C P in each case, although generally by a small amount. However, it is worth noting that the fraction C P that is caused by soot emissions is dramatically reduced by the pulsations, especially in the 100 g cases, where the puffs are not so severe as to totally deplete all available oxygen. This effect, though minor from a total mass emissions standpoint, is important when the overall toxicity of incinerator emissions is taken into account. The C O and hydrocarbons are typically much easier to destroy in a well designed afterburner system than is the soot. In addition, many of the semi-volatile organics that are known respirable carcinogens, such as benzo-a-pyrene, fall in the range that is measured as soot. Soot is also of concern since it is not easily removed in most air pollution control devices, due to its small particle size. Polyethylene Tests Figures 5 and 6 depict the mass and CP emissions, respectively, from the polyethylene tests. The pulsations consistently decreased all measured surrogate PIC indicators, unlike the toluene tests. T H C , C O and soot all showed a decrease, although the decrease in C O was somewhat less than the decrease in T H C and soot. The polyethylene data hilight the usefulness of using a performance indicator like C P to determine the effectiveness of combustion. Polyethylene burns somewhat slower than toluene and as such doesn't produce as extreme oxygen deficiencies in the incinerator. In addition, polyethylene produces copious amounts of soot, C O and T H C without being overly biased for or against any particular surrogate indicator. Figure 5 shows that the pulsations decreased the total mass emissions from burning polyethylene by 2 5 % , while Figure 6 shows that the pulsations reduced the C P by nearly 4 0 % . Finally, just as in the toluene case, the pulsations substantially reduced the soot emissions. 6 V-28 |