A method of purifying air via a pre-purification unit (PPU) of an air separation unit (ASU) system having a pre-PPU chiller that is upstream of the PPU to cool compressed air before the compressed air is fed to the PPU can include passing air through an adsorber of the PPU to pass the air through a bed of adsorbent material within a vessel of the adsorber. In response to the pre-PPU chiller being determined to have an issue resulting in the pre-PPU chiller being tripped or requiring the pre-PPU chiller to be taken off-line, continuing to operate the ASU system at a full capacity even though nitrous oxide (N2O) within the air output from the PPU exceeds a first pre-selected threshold and is below a second pre-selected threshold associated with carbon dioxide (CO2) breakthrough. An ASU and a PPU can be designed to implement an embodiment of the method.

Described herein is a an adsorbent and/or absorbent composition, a method of preparing the adsorbent and/or absorbent composition, and method of treating a fluid stream with the adsorbent and/or absorbent composition. Alumina and carbon are combined with polyacrylamide (PAM) powder and water in preferred proportions and impregnates such as Group 1A metal hydroxides. Group 7A salts of Group 1A metals optionally can be added.

A method for removing contaminants from a gas stream including contacting a gas stream comprising hydrocarbons and sulfur contaminants with a modified nanocomposite adsorbent. Also provided are compositions and processes for forming compositions of a modified nanocomposite adsorbent composition for removing sulfur contaminants from a hydrocarbon stream. Additionally, provided is system for removing sulfur impurities from a gaseous hydrocarbon stream, where the system includes a plurality of adsorbent vessels arranged in series, where the adsorbent vessels include an emulsion of a modified nanocomposite adsorbent composition.

A method for removing contaminants from a gas stream including contacting a gas stream comprising hydrocarbons and sulfur contaminants with a modified nanocomposite adsorbent. Also provided are compositions and processes for forming compositions of a modified nanocomposite adsorbent composition for removing sulfur contaminants from a hydrocarbon stream. Additionally, provided is system for removing sulfur impurities from a gaseous hydrocarbon stream, where the system includes a plurality of adsorbent vessels arranged in series, where the adsorbent vessels include an emulsion of a modified nanocomposite adsorbent composition.

A photocatalyst filter is provided. The photocatalyst filter includes: a base in which an internal space is formed. The internal space is permeable to fluid, and a plurality of photocatalyst beads are provided in the internal space, wherein a surface of the internal space is reflective.

Embodiments of the present disclosure describe a metal-organic framework (MOF) composition comprising a plurality of metal clusters, wherein the metal is chromium; and one or more tetratopic ligands; wherein the metal clusters and ligands associate to form a MOF with soc topology. A method of making a MOF comprising contacting a template MOF of formula Fe-soc-MOF and a reactant including chromium in a presence of dimethylformamide sufficient to replace Fe with Cr and form an exchanged MOF of formula Cr-soc-MOF. A method of sorbing water vapor comprising exposing a Cr-soc-MOF to an environment; and sorbing water vapor using the Cr-soc-MOF.

Embodiments of the present disclosure describe a metal-organic framework (MOF) composition comprising a plurality of metal clusters, wherein the metal is chromium; and one or more tetratopic ligands; wherein the metal clusters and ligands associate to form a MOF with soc topology. A method of making a MOF comprising contacting a template MOF of formula Fe-soc-MOF and a reactant including chromium in a presence of dimethylformamide sufficient to replace Fe with Cr and form an exchanged MOF of formula Cr-soc-MOF. A method of sorbing water vapor comprising exposing a Cr-soc-MOF to an environment; and sorbing water vapor using the Cr-soc-MOF.

A porous aluminum-based metal-organic framework (MOF) comprises inorganic aluminum chains linked via carboxylate groups of 1H-pyrazole-3,5-dicarboxylate (HPDC) linkers, and of formula: [Al(OH)(C.sub.5H.sub.2O.sub.4N.sub.2)(H.sub.2O)].

A porous aluminum-based metal-organic framework (MOF) comprises inorganic aluminum chains linked via carboxylate groups of 1H-pyrazole-3,5-dicarboxylate (HPDC) linkers, and of formula: [Al(OH)(C.sub.5H.sub.2O.sub.4N.sub.2)(H.sub.2O)].

A material for removing a contaminant, the material including an adsorption material for adsorption of a contaminant and a decomposition material for decomposition of a contaminant, wherein the adsorption material and the decomposition material are complexed with each other, and a contaminant decomposition onset temperature of the decomposition material is equal to or lower than a contaminant desorption onset temperature of the adsorption material.