The present invention generally relates to a process for responding to feed flow variations by changing the process cycle and thereby increasing the productivity and capacity of the system significantly over constant process systems. This increases the flexibility a PSA system for customers that do not require a constant or uniform product flow rate and/or for processes and applications that experience feed streams that vary in flow, temperature, and/or composition.

A process and facility for producing gaseous methane by purifying biogas from landfill, can include a VOC purification unit, at least one membrane, a booster, a CO.sub.2 purification unit, a cryodistillation unit comprising a heat exchanger, a distillation column, and a subcooler, a deoxo, and a dryer.

A process and facility for producing gaseous methane by purifying biogas from landfill can include a VOC purification unit, at least one membrane, a CO.sub.2 purification unit, a cryodistillation unit comprising a heat exchanger and a distillation column, a deoxo, and a dryer.

A method for producing biomethane by purifying biogas from non-hazardous waste storage facilities involves compressing the initial gas flow, introducing the gas flow to be purified into at least one adsorber loaded with adsorbents capable of reversibly adsorbing the VOCs, and subjecting the VOC-depleted gas flow to at least one membrane separation step in order to partially separate the CO.sub.2 and O.sub.2 from the gas flow. The method also involves introducing the retentate from the membrane separation step into at least one adsorber loaded with adsorbents capable of reversibly adsorbing the major portion of the remaining CO.sub.2, subjecting the CO.sub.2-depleted gas flow exiting the adsorber loaded with adsorbents capable of reversibly adsorbing the major portion of the remaining CO.sub.2 to a cryogenic separation step in a distillation column in order to separate the O.sub.2 and N.sub.2 from the gas flow, and recovering the CH.sub.4-rich flow from the cryogenic separation step.

Systems and methods of separating components of a multi-component gas mixture are described herein. The systems include one or more packed bed columns packed with a biosorbent material. Upon passing the multi-component gas mixture through the packed bed column, substantially all of a polar component of the multi-component gas mixture is adsorbed by the biosorbent material and a non-polar component of the multi-component gas mixture is not substantially adsorbed by the biosorbent material.

The present invention relates to a method of controlling a defect structure in a chabazite (CHA) zeolite membrane, the CHA zeolite membrane having a controlled defect structure by the method and a method of separating CO.sub.2, H.sub.2, or He and water from a mixture of water and an organic solvent using the CHA zeolite membrane, and more particularly, to a method of controlling a defect structure in a CHA zeolite membrane that improves the separation performance by reducing the amount and size of defects formed in the CHA membrane structure when removing organic-structure-directing agents in the membrane through calcination at a low temperature using ozone.

The present invention is directed to an intensified process cycle that utilizes the adsorption beds present to a substantially greater degree allowing the processing of significantly more gas and/or the generation of significantly more product. The elimination of purge steps, reduction in equalization step times, and introduction of overlapping feed and equalization steps which normally cause a degradation in performance for equilibrium-based cycles, frees extra step for other actions to be taken, such as additional equalization steps, etc.

The present invention generally relates to a process that utilizes tunable zeolite adsorbents in order to reduce the bed size for nitrogen removal from a methane (or a larger molecule) containing stream. The adsorbents are characterized by the rate of adsorption of nitrogen and methane and the result is a bed size that is up to an order of magnitude smaller with these characteristics (in which the rate selectivity is generally 30) than the corresponding bed size for the original tunable zeolite adsorbent that has a rate selectivity of >100x.

The present invention generally relates to a pressure swing adsorption process for separating an adsorbate impurity from a feed stream comprising product gas, said process comprising feeding the feed stream to an adsorbent bed at a pressure of from about 60 psig to 2000 psig, wherein said adsorbent bed comprises adsorbent having: An isosteric heat of adsorption of from about 5 kJ/mol to about 30 kJ/mol, as determined by the LRC method, for the adsorbate, and an equivalent 65 kJ/mol or less isosteric heat of adsorption for the product,
wherein the adsorbent has a rate of adsorption for the adsorbate impurity that is at least 10 times greater than the rate of adsorption for the product gas as determined by the TGA method and recovering said product gas with a reduced a level of said adsorbate impurity.

The invention also related to an adsorbent useful in PSA separations, particularly separating N.sub.2 from methane, CO.sub.2 from methane O.sub.2 from N.sub.2 and the like.

The invention relates to a method for synthesizing silicoaluminophosphate sorbents such as SAPO-56 and SAPO-47 comprising the use of a specific structure directing agent (SDA) comprising a mixture of different types of amines The structure providing agent (SDA) comprises N,N,N,N-tetramethyl-1,6-hexanediamine (TMHD) and a co-structure providing agent (co-SDA) selected among primary, secondary and tertiary amines comprising up to 15 carbon atoms and mixtures thereof. A preferred SDA comprises isopropylamine, dibutylamine and tripropylamine The sorbents are particularly suitable for up-grading biogas such as separating carbon dioxide from methane.