The Use of Textile Yarns in Separation Processes

Abstract

A new method has been developed for preparing chromatography columns quickly, uniformly, and with high reproduci bility, using textile yarns as the solid adsorbent. Gas-chromatography experiments using columns packed in this way have revealed that rayon yarns have a high affinity for water vapor but allow other species, even those quite similar to water in size and chemistry, to pass through essentially unretarded. The degree of water retardation by rayon yam- filled columns has been found to depend on a number of controllable factors: charge volume and frequency of injection, column pressure and temperature, and yarn packing density. To demonstrate the usefulness of the rayon-water specificity for removing water from mixtures, two novel devices have been built that are capable of producing dry ethanol from aqueous mixtures on a laboratory scale at modest energy cost. One of these designs, taking advantage of the high tensile strength of yarn, makes use of a moving yarn loop to achieve almost continuous separation and a high yield of ethanol. Even if such processes do not turn out to be economically practicable for large-scale ethanol production, the concept of gas or liquid chromatography using bundles of yarns with suitable chemical properties should find application in many practical separation problems.