Generation of Transportation Fuel from Solid Municipal Waste Plastics

Moinuddin Sarker, PhD, MCIC Natural State Research, Inc., 37 Brown House Road (2nd Floor), Stamford, CT-06902, USA E-mail: [email protected]

ABSTRACT

Transportation fuels derived from imported fossil In urban areas in the United States and around the fuels are subjected to the price fluctuations of the world, vehicle emissions are the largest single global marketplace, and constitute a major expense source of air pollution and greenhouse gases. in the operation of a vehicle. Emissions from the Emissions from gasoline cars include unburned evaporation and combustion of these fuels , which are responsible for ground- contribute to a range of environmental and health level ozone and smog; nitrogen oxides (NOx), problems, causing poor air quality and emitting which contribute to ozone and acid rain; greenhouse gases that contribute to global warming. monoxide (CO), a toxic byproduct of incomplete Alternative fuels created from domestic sources combustion and a health hazard; sulfur dioxide have been proposed as a solution to these problems, (SO2), which contributes to acid rain; and carbon and many fuels are being developed based on dioxide (CO2), a greenhouse gas that contributes to biomass and other renewable sources. Natural State global warming. The exhaust from gasoline Research, Inc. proposes a different alternative vehicles or from evaporative emissions include fuel which is produced from abundant many other harmful compounds, including benzene, waste plastic materials. This fuel burns more toluene, xylene, styrene, 1,3-butadiene, aldehydes, efficiently and cleaner than commercial gasoline ketones, phenols, halogenated hydrocarbons, and and diesel. The process exists to efficiently convert trace metals. waste plastic into a reliable low cost source of fuel. According to a recent study, United States Keywords: waste plastic, hydrocarbon fuel, consumes ~20.7 million barrels of fuel everyday transportation fuel, thermal cracking, gas [1]. With this high level of consumption, the non chromatography, differential scanning calorimetry. renewable fossil fuel sources will be depleted in the near future. In order to preserve these non- INTRODUCTION renewable sources, many nations and countries around the world are focusing a lot of research on In the United States and in most part of the globe, finding an alternate renewable source to the non transportation fuels are predominantly derived from renewable fossil fuel. imported fossil fuel, which creates an economic and political dependence on foreign supplies. In recent Alternative fuels developed from a reliable domestic source have the potential to overcome many of these economic / environmental problems and help us preserve our non renewable fossil fuel period, gasoline and diesel have been subject to source, by providing a steady, low cost source of large price swings that strongly affect regional fuel, by providing local employment in energy economic and transportation planning and production, and by providing fuel types that are budgeting. Economic, political, and environmental cleaner and produce fewer harmful emissions. Some pressures provide the motivation to reduce the use of the major alternative fuel research have been of conventional transportation fuels and a growth in focused on biomass for example, creating cellulosic the interest for alternate sources to these ethanol from non-edible biomass sources. However, conventional transportation fuels.

biomass energy requires large amount of arable land No additional chemicals are used in the thermal to be devoted to the cultivation of plant sources. liquefaction phase. The fuel is filtered using a commercial fuel filter that operates using There are also strong benefits in deriving alternative coalescence and centrifugal force. fuels from waste plastic materials because plastics are predominantly manufactured from petroleum Small-scale conversion tests have been performed products. Waste plastic is abundant and its disposal with the simplified process shown in Figure 1, on creates large problems for the environment. Plastic various waste plastic types: High density does not break down in landfills causing lands to be polyethylene (HDPE, code 2), low density contaminated, it also causes severe problems in city polyethylene (LDPE, code 4), polypropylene (PP, water ways, marine ocean life and natural ground code 5) and polystyrene (PS, code 6). These plastic water sources. Plastics are not easily recycled, and it types were investigated singly and in combination degrades in quality during the recycling process. with other plastic types. In the laboratory scale However, chemical processes such as pyrolysis and process, the weight of a single batch of input plastic de-polymerization can be used to safely convert for the fuel production process ranges from 300 plastics into hydrocarbon fuels that can be used for grams to 3 kilograms. The plastics are collected, transportation [2-4]. The United States produces 30 optionally sorted, cleaned of contaminants, and cut million tons of waste plastic per year, and ~300 or divided into small pieces prior to the thermal million barrels of fuel can be obtained, using a liquefaction process. It should be noted here that factor of one ton of waste plastics yielding 10 NSR process does not exclude the use of random barrels of fuel using the process described in this mixtures of plastic types. manuscript. Preliminary tests on the produced NSR fuel have Natural State Research, Inc. (NSR) has developed a shown that it is a mixture of various hydrocarbons different alternative hydrocarbon fuel which is having a range of carbon chain lengths from C3 to produced from abundant solid waste plastic C27. The produced NSR fuel density is typically materials. The NSR fuel contains additional 0.776 g./ml which is slightly higher than the density hydrocarbons in the range of C3-C27 as compared of commercial gasoline (0.711 – 0.770 g./ml) and with commercial gasoline with an rating of lower than the density for kerosene (0.820 g./ml). 87 (gasoline-87) in the hydrocarbon range C4-C9. The fuel is highly flammable and volatile, contains high heat capacity, and has been shown to The conversion process of converting waste plastic successfully run a gas-powered generator, Diesel materials to liquid hydrocarbon fuel has been generator, a gas-powered lawn mower and an successfully demonstrated in a laboratory scale. automobile. The advantages of NSR’s technique are its simplicity, which would allow municipalities to The filtered fuel obtained goes through another construct local fuel production plants; its ability to thermal distillation process. Early 40% of the handle many plastic types; and its ability to produce distillate was collected. It was named “NSR double a variety of fuel types for different transportation condensed fuel 1st collection” or “NSR-1”; another needs, e.g., for gasoline, diesel, or aviation fuel 50% was collected and named “NSR Double engines. condensed fuel 2nd collection” or “NSR-2” and the last 10% remains in the double distillation boiling PROCESS DESCRIPTION flask and it is termed “Residual Fuel” or “NSR-3”.

The process involves heating the plastic to form To obtain further refined grade, NSR is working on liquid slurry (thermal liquefaction in the range using fractional distillation to separate the mixed 370°-420°C), distilling the slurry in with or without waste plastic to individual category fuels. The fuels cracking catalyst, condensing the distillate to that will be obtained are; (a) Gasoline, (b) Naphtha, recover the liquid hydrocarbon fuel, and routing the (c) Aviation / Jet fuel (Kerosene), (d) Diesel fuel, remaining slurry residue back into fresh slurry to and (e) Fuel oil. undergo another distillation/condensation process.

Figure 2: Chromatogram of NSR Double condensed 1st collection.

1. 2,4-Dimethyl-1-Heptene (C9H18) 2. Styrene (C8H8) 22 NSR Double Condesned 3. (C10H22) 4. 2,4-Dimethyl-1-Heptanol (C9H20 O) 20 2nd Collection 5. 1,4-Dimethyl-Cyclooctane (C10H20) 6. (C11 H24) 7. 3,7,11-Trimethyl-1-Decanol (C15H32 O) 8. 3-Dodecene (C12H24) 18 9. (C12H26) 10. 2,3,5,8-Tetramethyl-Decane (C14H30) 15 23 FUEL CHARACTERIZATION 11. 2-Tridecene (C13H26) 24 12. 3-Octadecene (C18H36) 12 13. 2-Isopropyl-5-Methyl-1-Heptanol (C11H24 O) 13 14. 1-Tetradecene (C14H30) 15. (C14H30) 25 16. 2,3,5,8-Tetramethyl-Decane (C14H30) 17. 1-Tridecene (C13H26) 9 Tests have been performed to investigate the 18. (C16H34)

14 19. 3,7,11-Trimethyl-1-Dodecanol (C15H32 O) 11 20. Hexadecane (C16H34) 8 17 composition of the produced fuel. Figure 2-6 show 21. 1-Nonadecene (C19H38) 26 22. (C17H36) 23. (C18H38) 5 Intensity (a.u) 6 24. Nonadecane (C19H40) gas chromatograms of five different fuels 25. Eicosane (C20H42) 21 26. Heniecosane (C21H44) 19 27 27. Heniecosane (C21H44) 29. Eicosane (C20H42) 3 16 illustrating the differences in carbon chain length: 10 28 30. Heptacosane (C27H56) 7 29 st 1 2 4 (2) NSR double condensed fuel 1 collection ( 30 NSR–1), (3) NSR double condensed fuel 2nd collection ( NSR–2), (4) commercial gasoline 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 (octane # 87), (5) Aviation fuel, and (6) commercial Retention Time in Minutes st diesel. The NSR 1 collection fuel contains Figure 3: Chromatogram NSR Doubled condensed hydrocarbon groups ranging from (C4-C12) 2nd Collection. compared with commercial gasoline with (C4-C9). Gas chromatography (GC) tests, Figures (2) and (3), show peak intensity distribution throughout the

range of hydrocarbon groups C3-C27, with 3 1. C4H10 12. C7H16 2. Ethylalcohol C2H6 O 13. Methyl-Cyclohexane C7H14 3. 2-Methyl-Butane C5H12 14. Toluene C7H8 retention times ranging from 2 min to 27 min. On 4. C5H12 15. Octane C8H18 5. Cyclopropene C5H10 16. Ethyl Benzene C8H10 6. 2-Methyl-Pentane C6H14 17. P-Xylene C8H10 the other hand GC tests for commercial fuels show 7. C6H14 18. P-Xylene C8H10 6 8. Methyl-Cyclopentane C6H12 19. 1-Ethyl-4-Methyl-Benzene C9H12 14 9. 2-Methyl-Hexane C7H16 20. 1,2,4-Trimethyl-Benzene C9H12 narrow ranges of hydrocarbon groups – Figure (4) 10. 3-Methyl-Hexane C7H18 11. 1,3-Dimethyl-Cyclopentane C7H14 7 for commercial gasoline (87) contains C4-C9; 4 11

2 9 Figure (5) for commercial aviation fuel contains 8 10 Intensity (a.u) C9-C19; Figure (6) for commercial diesel contains 5 Commercial Gasoline-87 1 1213 17 C7-C27. 20 16 15 18 19

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 10 1. 2-Methyl-1-Propene (C4H8) 10. 2,4-Dimethyl-1-Heptene (C9H18) Retention Time in Minutes 2. Pentane (C5H12) 11. Ethyl-Benzene (C8H10) 3. 2-Methyl-Pentane (C6H14) 12. Styrene (C8H8) 4. 2-Methyl-1-Pentene (C7H14) 13. 1-Methyl-Benzene (C9H12) 2 5. Hexane (C6H14) 14. 1-Decene (C10H20) 6. 2,4-Dimethyl-1-Pentene (C7H14) 15. 3,3-Dimethyl-Octane (C10H22) 7. 3,5-Dimethyl-2-Hexene (C8H16) 16. 3,7-Dimethyl-1-Octene (C10H20) 8. Toluene (C7H8) 17. Undecane (C11H24) Figure 4: Chromatogram of Commercial gasoline 9. Octane (C8H18) 18. Dodecane (C12H26) 87. 4

12 8 Intensity (a.u) NSR Double Condensed 1st Collection 11 3 1 7 9 5 14 6 15 16 17 13 18

24681012141618202224262830 Retention Time In Minutes

patterns of the commercial diesel. The

hydrocarbons distribution of NSR-2 fuel is observed 1. 2-Methyl-Octane (C9H20) 8 5 10 2. (C9H20) 3. 2,6-Dimethyl-Octane (C10H22) up to the retention time of 27 minutes which is the 4. 4-Methyl-Nonane (C10H22) 5. Decane (C10H22) 6. 4-Methyl-Decane (C11H24) same as commercial diesel. 7. 1,3-Diethyl-Benzene (C10H14) 13 8. Undecane (C11H24) 9. 3-Methyl-Undecane (C12H26) 10. Dodecane (C12H26) 15 11. 2,6-Dimethyl-Undecane (C13H28) 12. 2,6-Dimethyl-Heptadecane (C19H40) A comparative analysis, using a differential 13. (C13H28) 14. 2,6,10-Trimethyl-Dodecane (C15H32) 15. Tetradecane (C14H30) scanning calorimeter, shows that NSR fuel has a 16. Hexadecane (C16H34) 2 17. Hexadecane (C16H34) 16 18. Nonadecane (C19H40) higher boiling point (>94 °C) than that of the Intensity (a.u) 7 11 6 12 Commercial commercial gasoline-87 (68.14 °C). These values 9 4 14 17 Aviation Fuel 1 3 indicate that NSR fuel contains more long chain 18 hydrocarbon compounds than those in commercial

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 gasoline-87, and these chains can be shortened Retention Time In Minutes during the double condensation process. As shown in Figure 3, NSR’s double condensed filtered fuel 1st and 2nd collections, respectively, show the onset Figure 5: Chromatogram of Commercial Aviation of the boiling points to 94.52 °C and 194.52 °C. Fuel. Both GC and DSC data indicate that NSR fuel contains a higher percentage of volatile

1. Methyl-Cyclohexane (C7H14) 17. (C15H32) 2. Octane (C8H18) 17 18. Hexadecane (C16H34) hydrocarbon compounds. 3. Ethyl-Cyclohexane (C8H16) 19. Nonadecane (C19H40) 4. Ethyl-Benzene (C8H10) 20. Octadecane (C18H38) 5. P-Xylene (C8H10) 11 18 21. Nonadecane (C19H40) 6. Nonane (C9H20) 15 22. Eicosane (C20H42) 7. 3-Methyl-1-Ethyl-Benzene (C9H12) 19 23. Heniecosane (C21H44) 8. 1,3,5-Trimethyl-Benzene (C9H12) 24. Heniecosane (C21H44) 9. 2-Propyl-1-Methyl-Benzene (C10H14) 20 25. Nonadecane (C19H40) 10. Undecane (C11H24) 26. Nonadecane (C19H40) 10 13 11. Dodecane (C12H26) 27. Heptacosane (C27H56) 12. 6-Methyl-1,2,3,4-TetraHydro- 8 Napthalene (C10H12) 21 13. Tridecane (C13H28) 14. 2,6-dimethyl-1,2,3,4-TetraHydro- Napthalene (C12H12) 22 15. Tetradecane (C14H30) 16. 2,6,10-Trimethyl- Tetradecane (C17H36)

23 12 14 16

Intensity (a.u) 24 9 7 6 25 5 4 1 2 26 3 27 Commercial Diesel 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Retention Time In Minutes

Figure 6: Chromatogram of Commercial Diesel. Commercial gasoline (87) chromatogram (Figure 4) Figure 7. Differential scanning calorimeter (DSC) shows an even peak intensity distribution up to the curves of several fuels illustrating different onsets retention time of 9 min. For longer retention times, of the boiling points. the peak intensities are decreased. Thus, commercial gasoline has a higher intensity of Experiments with 2 ml samples showed that NSR hydrocarbon compounds (C4 to C9) at the lower fuel required 4.48 minutes to burn, while retention time, and fewer hydrocarbon compounds commercial gasoline-87 required 1.72 minutes to with longer carbon chain (C10 to C20) or none in burn. This indicates that NSR fuel should yield the retention time range of 9 to 27 min. It is also more energy than gasoline-87 because of NSR observed that commercial gasoline-87 has a lower fuel’s longer burning time. Gasoline-87 has higher intensity of straight chain hydrocarbon compounds concentrations of benzene, toluene, styrene, xylene, when compared with NSR fuel. and naphthalene compounds compared with the NSR fuel. Furthermore, unlike gasoline-87, NSR Commercial diesel chromatogram (Figure 6) shows fuel contains no sulfur, methyl trer-butyl ether a peak intensity distribution up to the retention time (MTBE), tret amyl-methyl ether (TAME) and (Di- of 27 minutes. The indicates that commercial diesel isopropyl Ether (DIPE). These emission test contains high molecular weight hydrocarbon parameters are obtained from EPA standard test compounds (C7 to C27). In a comparison with NSR result conducted at intertak laboratory in New fuels, the double condensed 2nd collection fuel Jersey. “NSR-2” matches the retention time and the peaks

AUTOMOBILE TEST DRIVING RESULT filtered fuel (1st collection) and commercial gasoline-87. We used NSR fuel (double condensed 1st collection) and commercial gasoline-87 for automobile test Emission Gas NSR Double Commercial driving. A 1984 Oldsmobile vehicle (V-8 powered Condensed 1st Gasoline 87 engine) was used for the test driving and one gallon Collection Fuel of fuel was used for both cases after complete CO 1200 1200 drainage of the pre-existing fuel in the fuel tank. H2S - 3 - 2 The test driving was done on a rural highway with O2 21.0 16.8 an average speed of 55 mph. CH4 5 0

Based on the preliminary automobile test driving, the NSR fuel has offered a competitive advantage in CONCLUSION mileage over the commercial gasoline-87. NSR fuel showed better mileage performance of 18 miles A simple thermal process for de-polymerizing waste per gallon (mpg) compared to 15 miles per gallon plastic to useful transportation fuel has been (mpg) with commercial gasoline-87. That’s an extra developed and further refined using a laboratory 3 miles more output from the NSR fuel. A diagram scale double condensation process and fractional is presented to blow for visual understanding. distillation process. Characterization studies by GC and GC-MS indicate the de-polymerization product V8 Engine Car Run Test Result in Miles is essentially all straight chain hydrocarbons when 18.5 NSR 1st Collection Fuel, NSR 1st Collection Fuel (18 Miles) Commercial Gasoline 87 linear thermoplastic polymers are used as the feed. 18 Both GC and DSC studies indicate the product 17.5 includes hydrocarbons ranging from C3 to C27, a 17 range that includes commercial gasoline-87 and 16.5 diesel fuel. Automobile test driving with double 16 condensed filtered NSR fuel shows competitive 15.5 Commercial Gasoline 87 , (15 Miles) advantage in mileage over commercial gasoline-87, 15 while using a low fuel efficient engine. A 14.5 calculated 16.7% higher mpg is observed with NSR 14 fuel when compared to gasoline-87. Further testing 13.5 1 is in progress with high fuel efficient engine. Figure 8: V8 Engine Car Run Test Result using ACKNOWLEDGMENTS NSR -1st Collection Fuel and Commercial gasoline 87 The author acknowledges the valuable contributions made by NSR science team, Dr. Richard Parnas and It is expected that NSR double condensed fuel will Dr. Sabir Majumder during the preparation of this show even higher performance with more fuel manuscript. efficient car such as V-4 engine and hybrid vehicles. Additional driving tests are in progress. REFERENCES

While performing the above mentioned automobile 1. U.S. Energy information Administration, world test driving, we have also checked the emission supply and consumption of petroleum products, from the fuel burning using ENMET MX 2100 Wikipedia, emission tester positioned 1 foot from the car http://en.wikipedia.org./wiki/Petroleum exhaust. The test results were found to be similar (see Table 1). 2. Y. Uemichi, Development of a catalytic cracking process for converting waste plastics to Table 1. Emission results (1 foot from car exhaust) petrochemicals, J. Mat. Cycles Waste for comparison between NSR double condensed Manage.,5(2), 89-93, 2003.

3. A. Marcilla, A. Gómez-Siurana and F. Valdés, Catalytic cracking of low-density polyethylene over H-Beta and HZSM-5 zeolites: Influence of

the external surface. Kinetic model, Polym. Degrad. and Stability, 92(2), 197-204, 2007.

4. G. Manos, “Catalytic Degradation of Plastic Waste to Fuel Over Microporous Materials” Chapter 7 in Recycling of Waste Plastics: Pyrolysis and Related Feedstock Recycling Techniques, (Eds: J. Scheirs, W. Kaminsky), J. Wiley, 193-208, 2006.

CONTACT:

Moinuddin Sarker, PhD, MCIC Vice President (R&D) Natural State Research Inc. 37 Brown House Road, (2nd Floor) Stamford, CT, 06902, USA Phone: 203-406-0675 Fax: 203-406-9852 Email: [email protected]