United States Environmental Protection Agency Municipal Environmental Research Laboratory Cincinnati OH 45268 Research and Development EPA-600/S2-81-201 Nov. 1982 Project Summary Development of Methods for the Stabilization of Pyrolytic Oils M. B. Polk and M. Phingbodhippakkiya In this study, capillary gas chroma- tographic, liquid chromatographic, and gas chromatographic mass spectro- metric procedures were developed for analyzing pyrolytic oils. The major components of the oils and the chemi- cal reactions that cause polymeriza- tion were identified. Some of the major components identified in pyro- lytic oils were ethanol, 1-butanol, guaiacol, naphthalene, eugenol, acet- aldehyde, and 4-hydroxy-3-methoxy- styrene. This Project Summary was devel- oped by EPA's Municipal Environ- mental Research Laboratory. Cincin- nati. OH, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back}. Introduction Annually, large amounts of agri- cultural waste are produced in the United States. The disposal of this waste material is becoming an increas- ingly more difficult and expensive matter. Agricultural wastes are largely lignocellulosic in chemical nature. Pyrolysis is one approach for converting agricultural, forestry, and municipal wastes to useful energy of chemical forms. The products resulting from the pyrolysis of the organic fraction of solid wastes include noncondensable gases, liquids, and a solid residue of carbona- ceous material or char. Analysis of the evolved pyrolytic gas stream indicates the presence of hydrogen, carbon dioxide, carbon monoxide, methane, ethane, and ethylene. The individual gas compositions very with pyrolysis conditions. The solid material remaining after pyrolysis is an impure carbon and ash. The liquid fraction of pyrolytic oil contains organics and water. The pyrolytic oils are mixtures of neutral compounds and strong and weak acids. The oils are viscous, sticky liquids at room temperature. The pyrolytic oils appear to oxidize and/or polymerize on standing. During this study, methods were developed for determining the chemical composition of the pyrolytic oils, and attempts were made to stabilize the pyrolytic oils against whatever changes they undergo. Methods and Results The pyrolytic oil distillate was analyzed on an Aerograph 1440 gas chromatog- raph with a flame ionization detector. The conditions were: a 10-ft by 1/8-in. stainless steel column packed with 2% OV-210on 100/120 mesh Supelcoport F-01409*; oven temperature program, 50° to 225° at 10°C per min; helium flow rate, 30 ml/min. Peak identifica- tions were made by noting the en- hancement of peak size when known substances were chromatographed with the distillate. Peak assignments are given in Table 1. •Mention of trade names or commercial products does not constitute endorsement or recommenda- tion for use. ------- The oil distillate was also analyzed on the Varian 3740 capillary gas chroma- tog raph under the same conditions. Stabilization studies were conducted to determine mechanisms that lead to polymerization of pyrolytic oils. When a chromatogram of a pyrolytic oil sample was compared with one made 9 months later, the observation was that iso- eugenol and 4-hydroxy-3-methoxy- styrene peaks disappear on aging of the oil. This finding substantiates our suggestion that cationic, chain-reaction polymerization or oligomerization is responsible for substantial increases in viscosity of the pyrolytic oils on aging. Also discussed is the potential of the pyrolytic oils as a source of chemicals. The full report lists chemicals present in pyrolytic oil and their prices as reported in Chemical Marketing Reporter. In an earlier EPA-supported study, "Pyrolytic Oils" (EPA-600/2-80-122), methods were developed to separate oils into fractions containing phenolics, polyhydroxy neutral compounds, neutral compounds of a high degree of aromat- icity, and volatile acidic compounds. The results of these methods will be useful in determining full potential of pyrolysis for production of chemicals and fuels. The full report was submitted in fulfillment of Grants Nos. R-804440010 and R-804440020 by Atlanta University, Atlanta, GA, under the sponsorship of the U.S. Environmental Protection Agency. Table 1. Typical Pyrolytic Oil Distillates Sample m/e (Relative Intensity %) 1 -Heptanol 2,3-Dimethylphenol 2,4-Dimethylphenol 2,6-Dimethylphenol Naphthalene 2-Methoxy-4-methyl phenol Veratrole 29(38). 31(251. 41(96). 42(56). 43(68). 54(68). 55(100), 56(30). 69/56). 70(96). 73(66). 84(25). 99(7). 100(8) 31(11). 36(30). 43(17), 45(12). 54(14), 56(10). 79(17). 80(11). 81(17).93(17). 107(75). 122(100) 31(2). 94(10), 107(60). 121(30), 122(100) 36(6). 43(8). 55(6). 80(25), 82(22), 94(20), 107(40), 122(100) 36(13), 43(25), 54(6). 67(5). 104(7), 128(100) 31(16), 35(44). 45(41). 54(14). 55(30), 56(14), 57(14). 59(30). 68(20). 69(20), 7O(30). 80(22). 81(18). 95(58), 123(100). 138(100) 29(4). 41(18), 52(12), 63(10), 64(12), 65(12), 93(38). 123(100). 138(97). 139(10) M. B. Polk and M. Phingbodhippakkiya are with Atlanta University, Atlanta, GA 30314. C. J. Rogers was the EPA Project Officer (see below for contact). The complete report, entitled "Development of Methods for the Stabilization of Pyrolytic Oils." (Order No. PB 82-108 150; Cost: $9.50. subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 For information contact N. B. Schomaker at: Municipal Environmental Research Laboratory U.S. Environmental Protection Agency Cincinnati. OH 45268 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 U S GOVERNMENT PRINTING OFFICE 1982—6"59-O I 7/O857 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 PS 0000329 STREET It 60604 ------- |