Abstract: An air separation apparatus and method in which a high pressure gaseous product is produced as a liquid, pumped to a delivery pressure and then vaporized prior to its discharge as product. In order to accomplish the requisite vaporization, a subsidiary stream of incoming air is compressed by a booster compressor and then passed into indirect heat exchange with the pumped liquid in a falling film evaporator. The falling film evaporator maintains an essentially constant temperature difference between the air and falling film, formed of the pumped liquid. As a result, a very small temperature differences can be maintained as compared with the conventional use of a thermosyphon reboiler. As a result, less booster compression is required for the subsidiary air stream over a prior art plant.

Abstract: A method for increasing the zeolite content of high zeolite content clay derived microspheres obtained by reacting porous precursor microspheres with a sodium silicate solution in the presence of seeds to crystallize zeolite Y in situ in macropores of precursor microspheres composed of a mixture of metakaolin and kaolin calcined to undergo the exotherm. The increased zeolite content is achieved by increasing macroporosity of the precursor microspheres and increasing the content of metakaolin in the precursor microspheres. The increase in zeolite is associated with an increase in catalytic activity and unexpectedly improved selectivity.