Abstract: Carbon dioxide sorption using a metal oxide-alkali metal carbonate sorbent typically requires a relative humidity of greater than 25% in order to obtain reaction rate constants of about 2.0 to 3.0 sec..sup.1 (see Equation 6). The incorporation of alkali halide salt into the metal oxide-alkali metal carbonate sorbent maintains rate constants of about 2.0 to about 4.0 sec..sup.1 at relative humidities below 25%. Therefore, the hygroscopic alkali halide salt attracts water, thereby providing the necessary hydroxide ions for enhanced absorption at low relative humidities.

Abstract: Crystals of the Zeolite Analcime (Analcite) Na.sub.2 O.Al.sub.2 O.sub.3.4SiO.sub.2.2H.sub.2 O are provided having a largest dimension greater than 50 micron. A method for preparing such crystals by mixing aqueous solutions of aluminium sulphate and sodium metasilicate, allowing a gel to form then heating, is provided. The presence of an organic water-miscible base encourages an increased crystal size. The crystals retain water strongly and a use for them in long term immobilisation of tritiated waste water is provided.

Abstract: A carbon dioxide absorber is made by separating sludge from exhaust water discharged upon manufacturing fresh mixed concrete or concrete secondary products, then dewatering the separated sludge, and drying and crushing the dewatered sludge into dry fine particles.

Abstract: A system for controlling the atmosphere of a container for use in the storage and/or transportation of perishable goods which includes adsorption apparatus for the selective adsorption in whole or in part and in a predeterminded order of any water vapor, carbon dioxide, oxygen or ethylene contained within the atmosphere, a blower for urging the atmosphere to the adsorption apparatus, and a conduiting for returning the controlled atmosphere to the container.

Abstract: Air is purified by being passed in sequence through a first, lower, bed of activated alumina particles which adsorb water vapor preferentially therefrom, and a second, upper, bed of zeolite 13X molecular sieve particles which adsorb carbon dioxide preferentially therefrom. The air passes upwardly through the first bed and downwardly through the second bed. Once fully loaded with the adsorbent components, the beds and are regenerated by the passage therethrough of hot regeneration gas. one part of the regeneration gas flows downwardly through the first bed; another part flows upwardly through the second bed. The hot regeneration gas causes the previously adsorbed components to be desorbed. Once regeneration has ended, and the beds have returned their adsorbing temperature, they may be used again to purify air.

Abstract: Recovery of hydrogen from hydrogen-containing gas mixtures by pressure swing adsorption is increased by utilizing an adsorbent membrane to concentrate hydrogen in the pressure swing adsorption reject gas and recycling the resulting hydrogen-enriched stream to the feed of the pressure swing adsorption system. Lower compression requirements are realized compared with the use of polymeric membranes for the same service because the hydrogen-enriched stream is recovered from the adsorbent membrane as nonpermeate at essentially the membrane feed pressure. Simultaneous permeation of carbon dioxide and methane occur in the adsorbent membrane, which can be operated at feed pressures as low as 5 psig when hydrogen is used as a sweep gas.

Abstract: This invention relates to a process for treating a feed gas stream containing CO.sub.2 and mercaptans by contacting the feed gas stream with a CO.sub.2 -selective adsorbent under conditions effective to produce a CO.sub.2 -depleted feed gas stream which is thereafter subjected to contact with an alkaline scrubbing solution under mercaptan absorption conditions effective to produce a mercaptan- and a CO.sub.2 -depleted product gas stream and a mercaptide-containing scrubbing solution. At least a portion of the product gas stream may be utilized to regenerate the CO.sub.2 -selective adsorbent and the mercaptide-containing scrubbing solution may be regenerated by contacting same with oxygen in the presence of an oxidation catalyst.

Abstract: A gas-scrubber apparatus, including a chamber having an inlet means for receiving polluted gases to be scrubbed and having outlet means through which scrubbed gases are discharged, and heating elements for heating the chamber to maintain the polluted gases at predetermined temperature levels between the inlet means and the outlet means. The chamber includes a reaction zone for receiving a mixture of solid scrubbant materials for reacting with the polluted gases and a gas blower for directing the polluted gases to travel through the chamber to react with the scrubbant materials. At least one scrubber assembly is mounted in the reaction zone of the chamber having a baffle for collecting the polluted gases in the area adjacent the wall of the chamber.

Abstract: Improved processes for treating gas streams containing hydrogen sulfide, carbon dioxide, water vapor and methane, particularly natural gas streams. The processes rely on the availability of two membrane types, one of which has a hydrogen sulfide/methane selectivity of at least about 40 when measured with multicomponent gas mixtures at high pressure. Based on the different permeation properties of the two membrane types, optimized separation processes can be designed. The membrane separation is combined with non-membrane treatment of the residue and/or permeate streams.

Abstract: A two stage pressure swing adsorption process is set forth for producing high purity oxygen from a feed air stream wherein carbon dioxide, water and preferably nitrogen are removed in the first stage and wherein an oxygen selective adsorbent is used to adsorb oxygen in the second stage. The oxygen product is recovered upon depressurization of the second stage. The high purity of the oxygen product is achieved by rinsing the oxygen selective adsorbent with oxygen prior to the depressurization step. A key to the present invention is that the effluent streams from the second stage feed and rinse steps are used to regenerate the first stage adsorbent(s) in a specific regeneration scheme.

Abstract: Novel polyarylamide derived activated carbon materials are provided by a process comprising the carbonization of polyarylamide fibre at a temperature in excess or 400.degree. C. followed by activation at elevated temperature. The novel materials have the ability to adsorb relatively large quantities or carbon dioxide compared to other activated carbonized polymer materials, Preferably the carbonization and activation steps are carried out by raising the temperature of the materials to between 840.degree. C. and 880.degree. C. in carbonizing/activating atmospheres respectively.

Abstract: A pressure swing adsorption process is set forth for the recovery of two gas products at high recovery and high purity using the steps of adsorption, depressurization, low pressure purge, evacuation and repressurization. The purge effluent and a portion of the depressurization effluent are used to partially accomplish the repressurization step.

Abstract: An apparatus and process is provided for the production of hot mix asphalt (HMA) by the treatment of virgin material alone or adding reclaimed or recycled asphalt pavement (RAP) of up to 100% of the HMA comprised of reclaimed asphaltic pavement (RAP). The HMA is first heated in either a parallel or a counter flow rotating drum which is supplied with hot combustion gases generated by a remote low NO.sub.x burner. The temperature of hot gases entering the drum is from about 400.degree. to 2,000.degree. F., and the temperature of gases exiting from the drum is from about 130.degree. to 220.degree. F. The HMA material optionally can be subjected to microwave radiation to raise the material to a final temperature, or optionally to only reorient the dipolar molecules of the material without any measurable heating of the material. The exhaust gas is treated and made environmentally safe.

Abstract: A process for separating a feed gas mixture into a more strongly adsorbable component and a less strongly adsorbable component in a plurality of adsorbent beds containing an adsorbent selective for the more strongly adsorbable component using pressure equalization between beds after initial depressurization to provide a purge gas, using countercurrent evacuation wherein at least two adsorption beds are countercurrently evacuated simultaneously in overlapping countercurrent evacuation steps in the plurality of adsorption beds, and using a combination of less strongly adsorbable component and feed gas mixture to repressurize the adsorbent bed. Oxygen product can be recovered from air at high recovery using the process.

Abstract: A gas separation process and a unit therefor. The process comprises the steps of: introducing a gas consisting of two or more components into an adsorption system in which adsorbent particles circulate in a fluidized state, thereby to allow, at atmospheric pressure or an elevated pressure, the adsorbent particles to adsorb a gas component to be separated from the gas; transferring the adsorbent particles adsorbing the gas component to a desorption system; and then desorbing the gas component from the adsorbent particles in the desorption system which is regulated to have either a lower pressure or a lower pressure and a higher temperature than the adsorption system.

Abstract: Reaction rates in chemisorption reactions involving solid reactants and gaseous ligands are improved by maintaining optimized solid density throughout the reaction. Methods and apparatus which restrict volumetric solid expansion, compression of the solid reactant, and mixture with inert solid porous or particulate materials are disclosed.

Abstract: A carbon dioxide consuming material and a method for manufacturing it from waste released in the building industry, including: a primary crushing step 5 for crushing concrete fragments 1 under a pressure; a secondary crushing step 7 for crushing or smashing primary-crushed concrete fragments 11 from the primary crushing step by utilizing a grinding motion in a highly dense and pressurized condition; and a screening and separating step 8 for mixture of products obtained by the secondary crushing step.

Abstract: The present invention is a process for recovering hydrogen from dilute refinery off gases using a vacuum swing adsorption process having a simultaneous cocurrent depressurization to provide purge gas for another bed under the influence of a vacuum and countercurrent depressurization to vent void space gas and/or adsorbed gas to ambient.

Abstract: A process for obtaining highly-purified gas by selectively separating at least one gaseous impurity from a gaseous mixture by the known pressure swing adsorption method uses a holding column of the feed-in/feed-out sequence retaining type and at least three adsorption columns containing adsorbents. Each adsorption column is pressurized and depressurized in cycle to repeat adsorption and desorption steps. During this, the holding column is used as an intermediate gas reservoir to improve the efficiency of the separation. In this invention, the capacity of the holding column is insufficient to hold the whole amount of purge gas.

Abstract: A pressure swing adsorption process is set forth for the recovery of two gas products at high recovery and high purity using the steps of adsorption, depressurization, evacuation and repressurization. A portion of the depressurization effuent is used to partially accomplish the repressurization step.

Abstract: A method of compressing oxygen includes passing the oxygen into a vessel 12 containing finely divided material. Next a driving gas, for example, air is compressed to a greater pressure than the oxygen and passed through the vessel 12 and the bed of material contained therein which creates a plug flow effect such that the oxygen is compressed by the air substantially without back-mixing.

Abstract: A process for separation of a gas mixture containing three components, e.g. a mixture comprising hydrogen, carbon monoxide and carbon dioxide produced by steam reforming a hydrocarbon, by pressure swing adsorption is disclosed.