reflux ratio distilling head. Between the Corad head and the top of the column, a feed line from a constant flow bellows pump was introduced. The column had been calibrated with a test mixture of ethylbenzene and p-xylene, whose mixture possesses a relative volatility of 1.06. The column calibrated 4.5 theoretical plates at total reflux. A run was made with a charge comprising approximately 10% methylcyclohexane and 90% toluene in the stillpot. The column was operated at total reflux for about an hour and then the pump started at a rate to deliver about one part of extractive agent to one part of methylcyclohexane-toluene being boiled up. The extractive agent in this example was 33.3% phthalic anhydride, 33.3% maleic anhydride, and 33.3% glycerol triacetate. The following data were obtained: Time, Composition, Composition, Relative hours % MCH, % Tol. % MCH, % Tol. Volatility 1 88.7 11.3 6.4 93.6 2.87 2 97.0 3.0 5.3 94.7 4.11 3 97.8 2.2 4.9 95.1 4.48It will be noted that after about two hours, equilibrium has been achieved and the relative volatility remains essentially constant in the range 4.1 to 4.5. Without the extractive agent it would have been 1.50. Overhead Stillpot LITERATURE CITEDAtlani, M., V. Corn, and C.

Particles of a coal char (from Montana lignite) were used in a fixed bed for cyclic separation of a mixture of hydrogen and methane. The column was operated in the temperature cycling mode between 25 and 250 OC at a total pressure ranging from 21 to 34 atm. The methane concentration was enriched from 50% to over 90%, which was the goal of separation for production of high-Btu gas. It has been shown that the coal char is as effective as a commercial activated carbon being used as the sorbent. The experimental data showed that pore diffusion is important in separation. A simplified porediffusion model was developed which gave satisfactory bredictions of the performance of temperatwe-swing separation. In the simplified model a parabolic intraparticle concentration profile was assumed and the computation was further simplified by using a particle volume-averaging technique.