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The nitrogen bases in eight high-bolllng crude oil distillates from four crude oils having different geological sources were characterized. Four basic compound types were found in all of the distillates-pyridine benzologs, dlaza compounds, amides, and carbazoles. A chromatographlcinfrared method was developed for the qualitative and quantitative determination of the major compound types. t h e data obtained using this method were compared with titration and total nitrogen data. This comparison demonstrated that the chromatographic-infrared method alone can be used to qualitatively and quantitatively analyze basic compound types in high-boiling petroleum distillates and that titration and total nitrogen data alone can be used to quickly estimate the kinds and amounts of major compound types in these distillates. The structures of the basic compounds were examined in detail using fluorescence, mass, and infrared spectrometry.Crude oil distillates may be separated into seven fractions-acids, bases, neutral nitrogens, saturates, monoaromatics, diaromatics, and polyaromatics-using the separation scheme developed by the Bureau of Mines in American Petroleum Institute Research Project 60 (1, 2 ) . Further characterization of these fractions is desirable to identify the major compound types. The polar compound types are important constituents of petroleum because, even in small amounts, they cause serious problems in processing and in the stability of the products. For example, the polar compounds cause catalyst poisoning and are involved with the formation of gums in products. Characterization of the acid fractions has been reported ( 3 ) . The analysis of base fractions according to compound types is discussed in this paper.Early work on petroleum bases has been reviewed by Lochte and Littman ( 4 ) . Much credit is due to the early workers who, without modern spectroscopic instrumentation, have identified many individual pyridine, quinoline, and benzoquinoline compounds. Recent research by Snyder (5-7) and Jewel1 and Hartung (8) has extended the compositional studies to include the identification of amides, compounds containing both nitrogen and sulfur, and diaza compounds. Quantitative estimates of the different compound types have also been made using mass spectrometry (5-7) and potentiometric titration (9-21).This investigation extends previous work by developing a standardized scheme of analyzing basic compound types in 370-535 "C and 535-675 "C petroleum distillates. Bases in crude oils from four different geological sources were studied to compare the composition of the base fractions.First described are titration data and elemental nitrogen and sulfur analyses of total base fractions. Second, a method is described involving adsorption chromatography and infrared spectrometry that was developed for the qualitative and quantitative determination of major compound types. T h e results obtained using this chromatographicinfrared method are then compared with the results of the Petroleum titration and total nitrogen ...

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The design of industrial catalysts requires that the diffusivity of the reacting species within the catalyst be accurately known. Nowhere is this more important than in the area of coal liquefaction and upgrading of coal liquids. In this area one is faced with the task of processing a number of heavy oils, containing metals and other contaminants, in a variety of process dependent solvents. It is important, therefore, on the basis of predicting catalyst activity, selectivity, and optimizing reactor performance, that the diffusivities of these oil species be accurately known. Several studies exist [l], emphasizing thk importance of diffusion in processes involving coal and petroleum liquids. Spry and Sawyer [2] measured the demetallization rates of a crude oil using various catalysts and found these rates to depend on average pore size, in agreement with their simple model, based on the theory of Anderson and Quinn [3]. Inoguchi [4] observed that optimum activity for desulfurization of heavy crudes occurs with catalysts with pore sizes of 1008, and for vanadium removal with pore sizes between 120 and 1408,. Eigenson et al. [ti] found increased catalytic activity for Moo3 on Also3, when the pore size increased from 70 to 1508,. Significant intraparticle diffusion effects have been observed during asphaltene cracking and the dekulfurization of asphaltenic and nonasphaltenic fractions of a residuum by Philippopoulos and Papayannakos [SI. Ternan and \ coworkers [7] have reported significant pore size effects during the catalytic processing of Athabasca bitumen. Studies have also been published on the importance of intraparticle diffusion during coal liquefaction and coal liquid upgrading, including those of Polinski and coworkers [8], Scooter and Crynes [9], and Yen et al. [lo]. Workers at Amoco have found [ll] that micropore volume in a critical pore size range, i.e. narrowly distributed about 1208, diameter pores, was very important in coal liquefaction catalyst activity. McCormick et al. [12] have shown during their hydrotreating studies that activities for both hydrogenation and dehydrogenation reactions are highly correlated (> 99% confidence) with the pore volume in the preferred range (60-2008,) in diameter. The importance of catalyst average pore diameter and pore length during the hydrocracking of solvent refined coals and lignites has been discussed by Berg and Kim [13]. Theoretical studies have also been published, which incorporate hindered diffusion in order t o predict optimal pore sizes during petroleum liquid upgrading [14] and catalytic coal liquefaction [15]. The molecules comprising coal liquids can range from less than 10 to several hundred 8, in diameter. Their size is, therefore, comparable t o the average pore size of most hydroprocessing catalysts. Thus, during processing, transport of these molecules into the catalyst occurs mainly by "configurational" or "hindered diffusion," which is the result of two phenomena occurring in 1 the pores; the distribution of solute molecules in the pores is a...