Alkanes in aqueous systems. II. The accommodation of C₁₂−C₃₆ n‐alkanes in distilled water

Abstract

Abstract The accommodation of n‐alkanes in the C 12 to C 36 range in distilled water was measured as a function of hydrocarbon supply, settling time, filtration pore‐size, and mode of introduction. Accommodation levels for individual hydrocarbons generally fell in the range of 0.01 to 100 mg/liter; liquids were accommodated to a greater extent than solids. Settling times of many days sharply reduced the measured accommodation, as did millipore filtration. The accommodation of a given n‐alkane showed a strong dependence on the supply of the n‐alkane in the equilibrating aqueous system. Binary mixtures showed a limited effect of one alkane on another except in the case of mixtures of a liquid alkane and a solid alkane, in which the presence of the liquid greatly enhanced the accommodation of the solid. Similarly supply ratios were reproduced for accommodated liquid alkanes except in those systems where the supply alkanes separated into co‐existing liquid and solid phases with compositions as determined by the phase rule for the particular hydrocarbon system. The accommodated alkane composition was the same as that of the liquid hydrocarbon phase. The same pattern was observed for fused mixtures of n‐alkanes in the C 12 to C 36 range, and on long‐term settling there was an over‐all, clearcut tendency for preferential accommodation of n‐alkanes in the C 16 to C 20 range at the expense of alkanes with both higher and lower carbon numbers.