COMPOSITION AND HEATING VALUE OF MUNICIPAL SOLID WASTE IN THE SPRING CREEK AREA

OF NEW YORK CITY

NORMAN CHIN PETER FRANCONERI The Port Authority of and Consulting Engineer

New York, New York New York and New Jersey

ABSTRACT

A comprehensive municipal solid waste (MSW) sampling program was conducted in the Spring Creek Area of New York City. MSW heating value, composition, and chemical analysis were deter­mined from a total of 61 samples. Thirty-four samples were taken during autumn 1978, and nine samples were taken during each of the following three seasons (1978 - 1979) to determine seasonal effects. Flyash and residue were sampled in the winter. The sampling techniques, laboratory pro­cedures, and program results are presented.

INTRODUCTION

To slow the decline of the region's economy and the exodus of indu&tries, The Port Authority of New York and New Jersey is developing indus­trial parks in the New York Metropolitan area. Conversion of the energy in New York City's MSW could generate sufficient energy to supply the energy needs of an industrial park. For example, an industrial park covering 240 acres (0.97 km2), with an energy demand of 54 MW and 100,000 1b/ hr (45,400 kg/h) of process steam, could be met by burning approximately 3500 tons/day (3175 tid) of MSW. Industrial park tenants would be supplied with energy at rates below what the utilities are charging. Low cost energy could be­'come one of many incentives drawing tenants to

an industrial park in New York City. A resource recovery plant to process 3500

tons/day (3175 tid) of MSW would cost over two hundred million dollars to build. Such a large investment justifies careful feasibility study includ­ing an accurate determination of the heating value and composition of MSW in the area. The composi­tion of MSW can vary from neighborhood to neighborhood, season to season, day to day, and truck load to truck load. It is important to deter­mine the composition and heating value through sampling.

SOURCE OF MSW SAMPLED

MSW consists primarily of residential waste and commercial/industrial waste. In the City of New York, residential waste is collected by the Depart­ment of Sanitation, and commerical/industrial waste is collected by private cartmen.

The proposed resource recovery facility/indus­trial park will be in the Spring Creek Area, shown in Fig. 1. MSW intended for use at the facility is presently delivered to the South Shore Incinerator and the Fountain Avenue Landfill. The boundary for the flow of MSW into the Spring Creek Area was established by including the Department of Sanitation Districts that deliver their wastes to the South Shore Incinerator or the Fountain Avenue Landfill. Samples were picked from private cart­men trucks and Department of Sanitation trucks that collect MSW within the boundary.

239

/

/

BROOKLYN

-

Betts Avenue Incinerator

• QUEENS

/ /'

\

LEGEND

,,- O£,Ul'liI£HT 0' SANITATION COL lEe no" OISTlller

I . • I •

SCALE IN MILES

FIG.1 BOUNDARY FOR THE FLOW OF MSW INTO THE SPRING CREEK AREA

TYPE AND NUMBER OF SAMPLES

The most recent annual carting records of Fountain Avenue Landfill and South Shore Incinerator indicated that 80 percent of the MSW was delivered by Department of Sanitation trucks, and 20 percent was delivered by the private cart­men. On this basis, it was decided to sample two residential truck loads and one commercial/indus­trial truck load each day. During October 1978, samples were taken Monday through Saturday for two consecutive weeks. It was originally intended to take 36 samples during October 1978, but operating difficulties hampered the effort, and only 34 samples were taken. During each of the following three seasons, nine samples were taken during a one-week period; three on Monday, three on Wednesday, and three on Friday.

SAMPLING LOCATION AND

EQUIPMENT ARRANGEMENT

Sampling took place at the South Shore Incinera­tor, which is located within the boundary of the Spring Creek Area. The City of New York made

240

the South Shore Incinerator tipping floor available for sampling purposes during afternoons, when tipping floor activity ceased.

The sampling equipment layout is provided in Fig. 2. Three functional areas were required: Quartering Area, Compositional Analysis Area, and Shredding Area. The Quartering Area, where the sample was reduced to manageable size, was located on the tipping floor. To facilitate lab­oratory analysis, combustible items had to be shredded. However, the shredder could not be located on the tipping floor because this would interfere with incinerator operations. As a result, the Shredding Area had to be located in a storage room some distance from the Quartering Area. The shredder location established the location of the Compositional Analysis Area, which had to be close to the shredder. The front end loader trans­ported the samples from the Quartering Area to the Compositional Analysis area.

SAMPLING PROCEDURE

The sample truck load was first weighed and dumped on the tipping floor. Oversized objects

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FIG.2 SA MPLING EQUIP MENT LAYOUT AT SOUTH SHORE INCINERATOR

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such as rubber tires, iron pipes, wooden crates, heavy corrugated boxes etc. were hand picked, removed and weighed. The front end loader then deposited every sixth bucket load in the quarter­ing area, and the other five bucket loads into the storage pit, until the whole truckload was deplet­ed.

The sample deposited in the quartering area was then evenly spread over the 26 ft (7.9 m) diameter circle and separated into four quadrants. Two opposite quadrants were removed and dis­carded. The remainder was again spread evenly over the 19 ft (5.6 m) diameter circle, quartered and the MSW in the two opposite quadrants was discarded. The remainder was again spread evenly over the 13 ft (4 m) diameter circle. The quarter­ing procedure continued until the sample was reduced to about 3/4 cu yds (0.6 m3).

The sample was then transferred to the 6 ft (1.8 m) diameter circle and further reduced to two 6 ft3(0.2 m3) samples, one for composition anal­ysis and the other for moisture determination.

The moisture sample was further reduced to 1 fe (0.03 m3), placed into a double plastic bag, sealed, labeled and delivered to the laboratory for moisture determination.

The composition analysis sample was then spread over one of the circles and hand sorted in­to eleven classified containers and weighed. The eleven categories used were:

1. Paper 2. Wood 3. Plastic 4. Glass 5. Ferrous Metals 6. Aluminum 7. Other Nonferrous Metals 8. Sand 9. Organic

10. Rags 11. Miscellaneous

With the exception of plastic, the combustible components were shredded to a size suitable for further shredding in the laboratory. Plastic could not be shredded because it jammed the shredder. A l ft3 (0.03 m3) shredded sample was placed in­to a plastic bag, sealed, labeled, and delivered to the laboratory for heating value determination.

LABORATORY PROCEDURES

Standard procedures for laboratory analysis of MSW are being developed by ASTM E-38. At the

time of the sampling and analysis program, there were no standard procedures for laboratory anal­ysis of MSW. However, standard procedures do exist in laboratory analysis of similar material. These standards include ASTM, ANSI, Standard Methods for Analysis of Water and Wastewater, and AOAC. The procedures used were based on modifications to ASTM, AOAC, or Standard Me­thods.

Heating value and composition were adjusted to reflect the oversized objects and plastic remov­ed during the various steps of the assay. The heat­ing value adjustment is shown in Table 1.

ASSAY RESULTS

The composition of residential waste samples is shown in Table 2, and commercial/industrial waste composition is shown in Table 3. The com­position of the combined residential and com­merical/industrial samples taken in autumn 1978 is provided in Table 4. There is a significant dif­ference in paper and metal contents of MSW from the Spring Creek area, other regions in the City, and the nationwide average. These differences indicate that known MSW composition of one region should not be used for another.

Table 5 shows the wide variation in moisture content of MSW from truck load to truck load. Because of the wide variation, it is advisable to take as many samples as possible to reach a reliable average.

The average moisture content of residential waste in the Spring Creek area is almost exactly the same as that of commercial/industrial waste. Usually, commercial/industrial waste is drier than residen tial waste.

The proximate and ultimate analyses of the residential waste samples are shown in Table 6, and the commercial/industrial waste analyses are shown in Table 7. The high chloride values in the ash should have been even higher since plastics were purposely excluded from the laboratory sample because they proved difficult to shred.

The percentages of sulfur and oxygen in the residential and commercial/industrial waste samples are presented in Table 8. These percent­ages do not vary Significantly from truck load to truck load.

The heating values for residential and com­mercial/industrial waste samples are shown in Table 9. The as-received average heating value was 4100 Btu/lb (9.-5 MJ/kg). This heating value has

242

TABLE 1 HEATING VALUE ADJUSTMENT FOR TYPICAL SA MPLE

(1) Sample number

(2) Laboratory sample weight, lbs

(3) Laboratory sample HHV, Btu

(4) Laboratory sample heat release, Btu

(5) Weight of oversized object from lab sample,

20-1 21. 5 6840 147,060

lbs 8.0 (6) Heat release of (5) above, Btu 18,750 (7) Weight of oversized object removed from

tru,ck sample allocated to lab sample, lbs 2.17 (8) Heat release of (7) above, Btu

(9) Total adjusted weight of sample (2)+ (5)+(7) above, lbs

(10) Heat release of adjusted sample (4)+(6)+(8) above, Btu

(11) Heating value of sample, Btu/lb

(12) Moisture fraction, %

(13) Adjusted heating value as-received, Btu/lb

Conversion Factors - 1 Ib = 0,4535 kg; 1 Btu = 1,055 J

15,544

31.67

181,354 5,726 0.219 4,472

TABLE 2 ADJUSTED COMPOSITION ANALYSIS FOR 24 AUTUMN RESI DENTIAL WASTE

SAMPLES

Paper

Wood

Plastic

Glass

Ferrous

Aluminum

Other Non-ferrous

Sand

Organics

Rags

Misc.

Minimum % 8.367

0.416

3.524

2.935

3.125

o

o

o

6.266

0.202

0.016

243

Maximum % 54.073

10.130

20.167

21.956

36.872

12.605

0·536

26.022

47.556

17.223

13·702

Mean % 29.986

3.474

8.108

10.114

11 .000

3·797

0.020 2.414

24.727

5·327

1.044

TABLE 3 ADJUSTED COMPOSITION ANALYSIS FOR 10 AUTUMN CO MMERCIAL! INDUSTRIAL WASTE SAMPLES

Paper

Wood

Plastic

Glass

Ferrous

Aluminum

Other

Minimum % 19.696

0.098

4.346

2·368

0.934

o

N.on-ferrous 0

Sand 0

Organics 12.250

Rags 0

Miscellaneous 0

Maximum % 62.889

12.734

29.451

21 .786

18.934

10.625

11 .108

39.759

19·238

12.916

Mean % 40.822

5·223

11.554

6.850

6.591

3·319

0.058

1·532

18.025

2.730

3·394

TABLE 4 COMPOSITION O F 34 AUTUMN SAMPLES MIXED RESIDENTIAL AND COMMERCIAL! INDUSTRIAL WASTES ADJUSTED FOR 80/20 RATIO

Paper

Wood

Plastic

Glass

Ferrous

Aluminum

Other Non-ferrous

Sand

Organics

Rags

Miscellaneous

Total

Residential Mean

% ,

29.986

3.474

8.108

10.114

11 .000

3·797

0.020

2.414

24.727

5·327

1.044

100.010

244

Comm'l/Ind'l Mean

% 40.822

5·223

11 .554

6.850

6.591

3·319

0.058

1·532

18.025

2.730

3.394

100.098

,

Combined Mean

% ,

32 .197

3.831

8.811

9.448

10.101

3·699

0.028

2.234

23.360

4.797

1·523

100.023

TABLE 5 MOISTURE SAMPLE ANALYSIS FOR AUTUMN DATA

24 Residential Samples

10 Comm'l/Ind'l Samples

MinimuDJ %

6.3

2·3

Maximum %

39.9

Combined mean

95% Confidence Interval Mean %

+ 21.8 - 3.9

+ 21.7 - 9.0

21·78 + 9.0

TABLE 6 CHEMICAL ANALYSIS OF 24 AUTUMN RESIDENTIAL SAMPLES

95 % Confidence Interval

Minimum % Maximum % Mean %

PROXIMATE ANALYSIS

Moisture 9.9 51.3 31.2 + 3.5

Volatiles 69.2 95·3 84.0 + 2.7

Fixed Carbon 0.2 3.6 1.2 ± 0.4

Residue 4.7 30.9 16.0 ± 2.7

Ul timate Anal;ysis

Carbon 27·7 41.1 35.8 ± 1.5

Hydrogen 2.6 5.6 4.6 ± 0.4

Nitrogen 0.13 1.31 0.66 t 0.14

Sulfate 0.10 0.97 0.48 ± 0.11

Ash Anal;ysis

Chloride (g/kg) 6.26 47·3 17.3 ± 4.4

pH 8.2 9.9 8.9 + 0.2

Caustic (mg/kg) 0 0.95 0.15 + 0.12

Total Alkalinity 5·09 27.61 10.43 + 2.06 (mg/kg)

245

TABLE 7 CHEMICAL ANALYSIS OF 10 AUTUMN COMMERCIAL/INDUSTRIAL SA MPLES

PROXIMATE ANALYSIS

Moisture

Volatiles

Fixed Carbon

Residue

ULTIMATE ANALYSIS

Carbon

Hydrogen

Nitrogen

Sulfate

ASH ANALYSIS

Chloride (g/kg)

pH

Caustic (mg/kg)

Total Alkalinity (mg/kg)

Minimum %

10.4

77.6

0·3

5·9

25·8

3·25

0.17

0.22

5·78

8.0

o

3·91

Maximum %

64.1

94.1

2.0

22·5

43·1

6.09

1.70

1.23

10.0

76.40

95 % Confidence Interval Mean %

31.4 :t 10.4

84.8 ± 3.8

0.8:t 0.4

15.3 ± 3·8

34.8 ± 3.8

4.76 ± 0.7

0.76 ± 0.36

0.61 ± 0.25

22.16 :t 15.4

9.0 ± 0.4

0.14 ± 0.17

15.21 ± 15.48

TABLE 8 CALCULATED OXYGEN AND SULFUR IN SAMPLES (Dry Basis)

24 Residential Waste Samples

% Sulfur * % Oxygen **

10 Commercial­Industrial samples

% Sulfur

% Oxygen ·Sulfur is calculated from sulfate value

Minimum

0.03

31.9

0.07

34·5

• ·Oxygen is calculated according to ASTM-O-3176-74

246

Maximum

0.32

58.8

0.41

64.1

95 % Confidence Interval Mean

0.16 ± 0.04

42.7 ± 2.7

0.20 :t 0.08

44.5 ± 5.9

,

TABLE 9 HEATING VALUES AND WEIGHTED AVERAGE CALCULATION ,

Minimum (Btu/lb)

Maximum (Btu/lb)

95% Confidence 'Interval Mean (Btu/l.b)

24 Residential Samples 2358 6004 3959 + 412 -

10 Commercial­Industrial Samples 2924 5987 4710 + 802

Waste Type

Residential

Comm'l/Ind'l

Annual Percent

79.6

20.4

Conversion Factor - 1 Btu/lb = 2326 J/kg

x

x

been adjusted for the plastics content that had to be removed to allow shredding of the samples. Because there are significant variations from truck load to truck load, it is necessary to test many samples to obtain a representative heating value.

SEASONAL EF FECT

Fig. 3 shows that the heating value appears to be fairly constant over the four seasons. There is a Significant increase in both paper and moisture during the winter and spring. Plastic and alumi­num content were fairly constant while ferrous metal content showed a slight variation.

CONCLUSIONS

Statistical analysis of the data included deter­mination of means, standard deviations, and con­fidence intervals. Data from all four seasons was evaluated to determine whether the seasonal vari­ations were statistically significant. Because of the relatively small sample size, close values from

He a.tiif Value (Btu lb)

3959

4710

-

=

=

Weighted Average

Weighted Average Heating Value

(BtuZlb)

3151

961 j :

4112 + 516 95% Confidence Interval

season to season, and large standard deviations, it was concluded that seasonal differences were not statistically Significant.

Although the four seasonal values were deter­mined, each set of seasonal results was summariz­ed to obtain mean values on an annual basis. The annual mean values were compared to national averages and other local survey data published in the literature. The comparison is provided in Taple 10.

The heating value, moisture and composition of MSW varies from truck load to truck load, from neighborhood to neighborhood, and from season to season. Reliability and validity of the average values determined depends heavily on the

number of samples taken and the con�cientious effort of the crew performing the sampling tasks. Gose supervision of the sampling crew i� crucial, and there should 'be as many samples taken as possible to assure reliable results. Reliability of results may influence the success of a resource re­covery project that will cost hundreds of millions of dollars.

247

7

6

5 50

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\" HEATING VALUE

0 0 0 ,-.. .-I 0

0 :< 0 .-I I:Q 4 40 ....1 :< ........ ,-..

� � E-< Z I:Q r.:I � '-' � � r.:I r.:I � Po. Po.

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SEP. OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG.

1979

FIG.3 SEASONAL VARIATIONS: CONVERSION FACTORS: 1 ton = 1.1023 t; 1 Btu/lb = 2326 J/kg

248

TABLE 10 COMPARISON OF D ATA COMBINED RESID ENTIAL AND COMMERCIAL/IND USTRIAL

WASTES

US EPA National Average1 1978

(%) Paper )1.20

Glass & Ceramics 10.00

Metals 9·00

Ferrous 7.90

Aluminum 0.80

O.N.F. 0.)0

Textile 1.60

Rubber & Leather 2.80

Plastic ).80

Wood )·50 Organics )6.60

Miscellaneous (sand,rock & dirt) 1.50

Total 100.00

Moisture 26

Heating Value, As-Received, Btu/lb 4,600

Conversion Factor - 1 Btu/lb = 2326 J/kg

ACKNOWLEDGMENTS

The efforts of Mr. William Ingram and Dr. Herbert Fox in this work are greatly appreciated.

REFERENCES

[1] Estimates by Franklin Associates, Ltd., for the

Betts Avenu� Incinerator 1971

(%)

) )

51.25

6.69

16.8) ---

4.7)

5·0)

2.17

1).)0

1.61

101.61

15·71

4,867

South Shore Incineratpr 1 978

C%) )2.20

9.45

i) .8) 10.1 0

).70 0.0)

4.80

0.48

8.81

).8)

2).)6

).27

100.Q)

21.79

4,11 2

Resource Recovery D ivision, Office of Solid Waste, U.S.

Environmental Protection Agency, January 1978.

[2] Kaiser, E. R., Kassner, D ., and Zimmer, C.,

Incinerator Grate Deterioration - Causes, Cures, and Costs, Report to the City of New York Environmental

Protection Administration, D epartment of Sanitation,

August 1972.

Key Words

Analysis

Composition

Data

Energy

New York

Refuse

249