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Breakthrough curves for the adsorption of propane, n-butane, and iso-butane mixture on 5A molecular sieve zeolite were obtained experimentally and theoretically at a constant temperature of 301 K. The equilibrium model and linear driving force model were used to predict the experimental breakthrough curves for this multicomponent mixture. The equilibrium model gave a satisfactory fit for experimental data. The model equations were solved by a numerical method based on backward finite difference with a fixed griding technique. The effects of feed flow rate (0.552-3.496 l/ min), feed concentration (60.72-141.68 mmol/l), and adsorbates composition (58.75-75.32%) on these breakthrough curves were examined.

Experimental and theoretical studies were reported on equilibrium isotherms of pure methane and ethane adsorption on 4A molecular sieve zeolite at 301 K. The experimental equilibria data were measured using the constantvolume method. The Langmuir, the Freundlich, and BET equations were used to fit the pure component experimental data. The results show that both the Langmuir and Freundlich equations correlated the pure component experimental data fairly well with a correlation coefficient of 0.998 and 0.977 for methane and ethane, respectively. The results of this study showed that ethane was more selectively adsorbed than methane on 4A molecular sieve zeolite.

Fractions 100-150, 150-200, 200-250°C were distilled from medium Iraqi crude oil.The thermo-oxidation stability experiments were carried out on original and inhibited (with Topanol 0) distillate fractions using the Alcor Jet Fuel Thermal Tester, over a temperature range 516-573 k. It was found that the antioxidant ( T o p a n o l 0 ) e f f i c i e n c y d e p e n d s on t h e f r a c t i o n s composition and the oxidation temperature. Only 30 PPM o f T o p a n o l 0 s t a b i l i z e s f r a c t i o n 100-150°C t o a considerable extent. Also, an inhibition effect is o b t a i n e d i n f r a c t i o n 1 5 0 -2 0 0°C b u t a t a h i g h e r antioxidant concentration (90 P P M ) . Only, slightinhibition effect was observed in fraction 200-250°C at low oxidation temperature (below 551 K), while effect will be of no value at higher oxidation temperatures.

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Different petroleum fractions (of aromatic content between 0 and 22%) distilled from northern and Sharki-Baghdad Iraqi crude oils and reformates (of aromatic content between 22 and 55%), in addition to artificial hydrocarbon mixtures (of aromatic content between 5 and 6O%), were prepared. The peak area of the 1650-1550 cm-1 band, representing the stretching vibration of the C=C bond in the aromatic ring, is proportional to the aromatic content of the reference mixtures. The aromatic contents of naphtha, kerosene and gas oil fractions and reformates were calculated from the measured peak areas and the aromatic contents of the reference mixtures. The determined values of the aromatic contents were in satisfactory agreement with those obtained by sulphonation for naphtha and kerosene fractions, elution adsorption chromatography for gas oil fractions and gasliquid chromatography for reformates.

Breakthrough curves for the adsorption of methane, ethane, and propane mixture on 4A molecular sieve zeolite were obtained experimentally and theoretically at a constant temperature of 301 K. The equilibrium model and linear driving force model were used to predict the experimental breakthrough curves for this multi component mixture. The equilibrium model gave a satisfactory fit for experimental data. The model equations were solved by a numerical method based on backward finite difference with a fixed griding technique. The effect of feed flow rate (0.385-3.465 l/ min), feed concentration (60.72-182.16 mmole/l), and adsorbates composition (11.73-20.11%) on the breakthrough curves were examined.