To illustrate the application of the data on technologies to the evaluation of options for an integrated MSW management strategy, this section compares the energy balance and air and water emissions for two strategies:
Mass burning produces about four times more energy per ton of MSW than is recovered from a landfill. Air emissions from mass burning include much smaller quantities of organics, but much larger quantities of metals, than air emissions from landfills. Ash monofills produce smaller quantities of leachate than landfills, and the leachate has a lower metals content as well. Strategies that include mass burning and shred-and-burn RDF require smaller volumes of landfill space than any other strategy, especially if the combustion strategy also includes separation and recycling.
For the nation as a whole, an average of 2-4% of the weight of incoming refuse is ferrous metals recovered for recycling from the ash. The energy saved by recycling the metal is an additional 0.36 million Btu per ton of MSW, or 4% of the net energy recovered by mass burning (see Exhibit II). That savings is not included in the data base.
Other Integrated Strategies Described in the Data Base
The computerized data base permits users to integrate RDF production and direct combustion with other MSW technologies to determine the energy and environmental implications of any integrated MSW management strategy. Exhibit II and the computerized data base provide calculations for the following important integrated strategies that include mass burning:
Table 5.3
ENERGY AND EMISSIONS FOR STRATEGY 2: MASS BURN
Total Collection Process(a) Disposal
Landfill space for residue (assuming a
depth of 50 ft., 10(-5) acres 0.27 0.27
Solid waste (lb) 545 545
Energy Required (million Btu) 1.59 0.079 1.51 0.0003
Energy Produced (million Btu) 10.3 0.00 10.30 0.00
Net Energy 8.70 -0.079 8.78 0.0003
Air Emissions
Particulates (lb) 0.08 0.02 0.066
Carbon Monoxide (lb) 1.47 0.79 0.63
Hydrocarbons (lb) 0.079 0.079 NA 0.00
Nitrogen Oxides (lb) 5.11 0.32 4.79
Carbon dioxide (lb) 1650 1650
Water (lb) 1140 1140
Methane (lb) 0
NMOC (lb) 0
Dioxin/furan {10(-6)lb} 0.014 0.014
SO(2) 2.45 2.45
HCI 1.40 1.40
Antimony {10(-6)lb} NA NA
Arsenic {10(-6)lb} 4.1 4.1
Cadmium {10(-6)lb} 8.0 8.0
Chromium {10(-6)lb} 19 19
Lead {10(-6)LB} 10 10
Mercury {10(-6)LB} 230 230
Nickel {10(-6)LB} 17 17
Zinc {10(-6)LB} NA NA
Total Heavy Metals {10(-6)lb} 288 288
Effluent
Leachate (gal) 10 10
Leachate(lb) 84 84
Chloride (lb) 1.17 1.17
Sodium (lb) 0.26 0.26
Potassium (lb) 0.14 0.14
TOC (lb) 0.0003 0.0003
Arsenic {10(-3)lb} ND ND
Cadmium {10(-3)lb} ND ND
Chromium {10(-3)lb} ND ND
Copper {10(-3)lb} ND ND
Nickel {10(-3)lb} ND ND
Lead {10(-3)lb} ND ND
Mercury {10(-3)lb} ND ND
Zinc{10(-3)lb} ND ND
Total Heavy Metals {10(-3)lb} ND ND
AOX (gal) ND ND
(a) Mass burn
(b) This is total dioxin/furan as specified by EPA in CFR, 1991a
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Table 5.4
ENERGY AND EMISSIONS FOR STRATEGY 1: LANDFILL WITH GAS RECOVERY
Total Collection Process Disposal
Landfill space (assuming a depth of
50 ft), 10(-5) acres 2.00 2.00
Solid waste (lb) 2000 2000
Energy Required (million Btu) 0.081 0.079 0.002
Energy Produced (million Btu) 2.20 0.00 2.20
Net Energy (million Btu) 2.12 -0.079 2.20
Air Emissions
Particulates (lb) 0.02 0.02
Carbon Monoxide (lb) 0.79 0.79
Hydrocarbons (lb) 0.08 0.08
Nitrogen oxides (lb) 0.32 0.32 NA
Carbon dioxide (lb) 225 225
Carbon dioxide-combustion (lb) 212 212
Water (lb) 188 188
Methane (lb) 14.34 14.34
NMOC (lb) 0.75 0.75
Dioxin/furan {10(-6)lb}(a)
SO(2) {10(-3)lb}
HCI {10(-3)lb}
Antimony {10(-6)lb}
Arsenic {10(-6)lb}
Cadmium {10(-6)lb}
Chromium {10(-6)lb}
Lead {10(-6)lb}
Mercury {10(-6)lb}
Nickel {10(-6)lb}
Zinc {10(-6)lb}
Total Heavy Metals {10(-6)lb} NA NA
Effluent
Leachate(gal) 80 80
Leachate(lb) 667 667
Chloride 1.13 1.13
Sodium (lb) 0.73 0.73
Potassium (lb) 0.60 0.60
COD (lb) 0.16 0.16
Arsenic {10(-3)lb} 86 86
Cadmium {10(-3)lb} 3 3
Chromium {10(-3)lb} 163 163
Copper {10(-3)lb} 43 43
Nickel {10(-3)lb} 108 108
Lead {10(-3)lb} 48 48
Mercury {10(-3)lb} 6 6
Zinc {10(-3)lb} NA NA
Total Heavy Metals {10(-3)lb} 457 457
AOX (lb) 1.08 1.08
(a) This is total dioxin/furan as specified by EPA in CFR, 1991a.
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