ANALYTICAL CHEMISTRY
352 The amount (0.71 millimole per gram) of nitrogen compounds as calculated from ultimate analysis exceeds the amount (0.38 millimole per gram) as determined by functional group analysis. The difference (0.33 millimole per gram) is taken as the amount of pyrroles or condensed pyrroles present which are N-substitilted and consequently do not contain an active hydrogen. The quantity (0.83 millimole per gram) of oxygen compounds obtained by ultimate analysis exceeds that found (0.24 millimole per gram) by functional group analysis and the difference (0.59 millimole per gram) is taken to be ethers. The observed average molecular weight of 235 for the neutral oil (Table I) corresponds to 4.25 millimoles per gram, and that portion unaccounted for as nitrogen- and oxygen-containing compounds is taken as the amount of hydrocarbons present. In columns 2 and 3, Table 111, the composition of the neutral oil is calculated on a weight percentage basis; first (column 2), on the assumption that there is not more than one functional group in any given molecule (compare column l), and second (column 3), on the assumption that one third of the nonhydrocarbon compounds contain both oxygen and nitrogen in one form or other (2). Additional data on the further resolution of the neutral oil are needed to determine which, if either, of these two assumptions is correct. Heretofore, ultimate analysis has shown only that repeated acid and alkali extraction failed to remove all the oxygen and nitrogen compounds. The data from functional group analysis show that almost half the nitrogen compounds remaining after acid and alkali extraction are basic and that almost three fourths of the oxygen compounds are ethers and that about one fifth the oxygen compounds are acidic. Although additional examination of these procedures is necessary to demonstrate their general applicability to the problem, the information obtained from their application to only one oil sample has contributed to the understanding of the chemical nature of coal hydrogenation oils. Quantitative data on the presence of pyrrole-type nitrogen compounds, both N-substituted and N-unsubstituted; ether-type and alcohol-type oxygen compounds; and primary, secondary, and tertiary amine nitrogen compounds have all been obtained for the first time. By means of functional group analysis in combination with ultimate composition and molecular weight, the quantitative
estimation of the various types of oxygen and nitrogen compounds in coal hydrogenation neutral oils now appears feasible and promises to be of considerable value in following the resolution of these complex mixtures and in studying the effects of process variables on the hydrogenation process. ACKNOWLEDGMENT
The authors wish to thank Max Katz for making the eodium aminoethoxide titrations, Joy S. Wolfarth for making the perchloric acid titrations, C. W. DeWalt, Jr., for making the analytical acetylations, and E. W. D. Huffman, Denver, Colo., for average of duplicate analysis in Table I. LITERATURE CITED
(1) Basu, A. N., and Glenn, R. A,, Fuel, 27, 96-9 (1948). (2) Ibid., 29,134-7 (1950). (3) DeWalt, C. W., Jr., and Glenn, R. A., ANAL.CHEM.,24, 178+ 96 (1952). (4) DeWalt, C. W., Jr., and Glenn, R. A., Division of Gas and Fuel Chemistry, 116th Meeting, AMERICAN CHEMICALSOCIETY, Atlantic City, S . J., 1949. (5) Glenn, R. A., Basu, A. N.. Wolfarth, J. S., and Katz, M., Fuel, 29,149-59 (1950). (6) Hirst, L. L., Eisner, A , , Field, .J. H., Cooper, H. M.,Abernethy, R. F., and Storch, H. H., U. 5‘. Bur. Mines, Tech. Pappr 646 (1942). (7) Kaplan, E. H., Storch, H. I
