Disclosed are a heterogeneous zeolite membrane and a method of preparing the same, and more particularly a heterogeneous zeolite membrane that has CHA and DDR zeolite structures by growing seed particles into a crystal structure different from that of the zeolite membrane and can thus separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

A method of producing p-xylene comprising the steps of separating the reformate feed in the reformate splitter to produce a benzene stream, a combined heavy stream, a xylene stream, and a toluene stream, converting the C9+ aromatic hydrocarbons in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent, separating the dealkylation effluent in the dealkylation splitter to produce a C9 stream and a C10+ stream, reacting the C9 stream, the toluene stream, the benzene stream, and the hydrogen stream in the presence of a transalkylation catalyst in the transalkylation reactor to produce a transalkylation effluent, separating the p-xylenes from the xylene stream in the p-xylene separation unit to produce a p-xylene product and a p-xylene depleted stream, converting the m-xylene and o-xylene in the p-xylene depleted stream in the isomerization unit to produce an isomerization effluent.

Methods and systems for producing and using multi-layer composite co-polyimide membranes, one method for producing including preparing a microporous or mesoporous membrane support material for coating; applying a sealing layer to the membrane support material to prevent intrusion into the membrane support material of co-polyimide polymer; applying a first permselective co-polyimide layer atop and in contact with the sealing layer; and applying a second permselective co-polyimide layer atop and in contact with the first permselective co-polyimide layer.

An acidic gas separation membrane sheet causes an acidic gas to selectively permeate therethrough. The acidic gas separation membrane sheet includes a first porous layer, a hydrophilic resin composition layer, and a second porous layer in this order. A second peel strength between the second porous layer and the hydrophilic resin composition layer is less than a first peel strength between the first porous layer and the hydrophilic resin composition layer. An average value of the second peel strength is within a range of greater than or equal to 5 N/m and less than or equal to 500 N/m.

An air intake system for an internal combustion engine is described, and includes a vapor capture element disposed in an interior portion of an air intake system. The vapor capture element includes a flexible Metal Organic Framework (MOF) material, wherein the flexible MOF material is reversibly controllable to a first state and to a second state in response to a control stimulus. The flexible MOF material is configured to adsorb hydrocarbon vapor when controlled to the first state and configured to desorb the hydrocarbon vapor when controlled to the second state.

A method for separating N.sub.2 from a hydrocarbon gas mixture containing N.sub.2 comprising the steps of: i) providing a bed of adsorbent selective for N.sub.2; (ii) passing the hydrocarbon gas mixture through the bed of adsorbent to at least partially remove N.sub.2 from the gas mixture to produce: (a) N.sub.2-loaded adsorbent and (b) N.sub.2-depleted hydrocarbon gas mixture; iii) recovering the N.sub.2-depleted hydrocarbon gas mixture; iv) regenerating the N.sub.2-loaded adsorbent by at least partially removing N.sub.2 from the adsorbent; and v) sequentially repeating steps (ii) and (iii) using regenerated adsorbent from step (iv); wherein the adsorbent comprises a pyrolized sulfonated macroporous ion exchange resin.

A method for separating natural gas liquids (NGLs) from a hydrocarbon gas mixture containing natural gas liquids and methane, comprising the steps of: i) providing a bed of adsorbent selective for NGLs over methane; ii) passing a hydrocarbon gas mixture containing methane and NGL through the bed of adsorbent to at least partially remove NGLs from the gas mixture to produce: (a) NGL-loaded adsorbent and (b) NGL-depleted hydrocarbon gas mixture; iii) recovering the NGL-depleted hydrocarbon gas mixture; iv) regenerating the NGL-loaded adsorbent by at least partially removing NGLs from the adsorbent; and v) sequentially repeating steps (ii) and (iii) using regenerated adsorbent from step (iv).

A computer-implemented method for designing and assessing the performance of a hollow fibre membrane contactor (MBC) in a natural gas sweetening process using a MBC model is described in an embodiment. The MBC model comprises model parameters, model equations and boundary conditions for calculating data associated with the natural gas sweetening process. The natural gas sweetening process comprises removal of acid gas from natural gas using a solvent comprising at least one component. The method comprises: (i) forming a regression model using empirical data; (ii) determining a Henry's constant of CO.sub.2 in the solvent using the regression model; (iii) inputting the determined Henry's constant of CO.sub.2 in the MBC model as one of the model parameters; and (iv) determining CO.sub.2 absorption in the solvent using the MBC model for designing and assessing the performance of the MBC.

Provided herein are in situ methods for fabricating a mixed-matrix membrane or a mixed-matrix hollow fiber membrane for increasing formation of zeolitic imidazolate framework nanoparticles inside the mixed-matrix membrane. Generally, in the method a polyimide polymer coated onto at least one support is hydrolzed with a base and the poly(amic acid)-salt film formed thereby undergoes ion exchange with a metal ion, treatment of the formed poly(amic acid)-metal salt film with an organic linker to produce metal-organic framework nanoparticles in situ, and imidization of the treated poly(amic acid)-metal salt film produces a polyimide/metal-organic framework mixed-matrix membrane or a mixed-matrix hollow fiber membrane module. Also provided is the mixed-matrix membrane and the polymer mixed-matrix hollow fiber membrane module fabricated by the methods and methods for separating a binary gas mixture via the fabricated mixed-matrix membrane.

Systems and methods for heat exchange during gas adsorption and desorption cycling, one method including removing heat from an adsorbent material during gas adsorption to the adsorbent material; storing the removed heat for later use during desorption of gas from the adsorbent material; heating the adsorbent material during desorption of gas from the adsorbent material using at least a portion of the removed heat; and recycling heat during the step of heating to prepare a working fluid for the step of removing heat via temperature reduction of the working fluid.