The present application relates to absorbents comprising tetraamine ligands grafted onto metal-organic frameworks and a method for using same for CO2 capture from fossil fuel combustion sources to reduce emissions. In particular, this application relates to capturing >90% by volume, preferable >99% by volume, CO2 emissions such that the emissions are negative, essentially removing CO2 from the combustion air.

The present disclosure relates to improved solid state sorbent materials and methods for controlling and enhancing carbon dioxide adsorption performance for selected metal-organic framework (MOF) materials. The present disclosure further relates to inventive methods using a novel class of diamine-appended metal-organic frameworks MOF absorbents displaying step-shaped adsorption isotherms with large carbon dioxide capacities. More specifically, the present disclosure relates to diamine-appended MOF materials exhibiting step-shaped adsorption isotherms that are employed in a method utilizing humidity to control and improve carbon dioxide adsorption performance. In addition, the present disclosure relates to diamine-appended MOF materials used in a process including a regeneration step with carbon dioxide and humidity level control to achieve deep carbon dioxide removal even from dilute, near ambient condition carbon dioxide streams as well as more concentrated industrial output streams spanning multiple orders of magnitude. The present disclosure also relates to scrubbing apparatus and methods employing the inventive MOF materials, methods, process steps and apparatus as disclosed to achieve rapid and deeper carbon dioxide capture without the need to pretreat column materials.

Polyamines with lengths carefully tailored to the framework dimensions are appended to metal-organic frameworks such as Mg.sub.2(dobpdc) (dobpdc4-=4,4′-dioxidobiphenyl-3,3′-dicarboxylate) with the desired loading of one polyamine per two metal sites. The polyamine-appended materials show step-shaped adsorption and desorption profiles due to a cooperative CO.sub.2 adsorption/desorption mechanism. Several disclosed polyamine-appended materials exhibit strong ability to capture CO.sub.2 from various compositions. Increased stability of amines in the framework has been achieved using high molecular weight polyamine molecules that coordinate multiple metal sites in the framework. The preparation of these adsorbents as well as their characterization are provided.

A method for removing carbon dioxide directly from ambient air, using a sorbent under ambient conditions, to obtain relatively pure CO.sub.2. The CO.sub.2 is removed from the sorbent using process heat, preferably in the form of steam, at a temperature in the range of not greater than about 130° C., to capture the relatively pure CO.sub.2 and to regenerate the sorbent for repeated use. Increased efficiency can be achieved by admixing with the ambient air, prior to contacting the sorbent, a minor amount of a preferably pretreated effluent gas containing a higher concentration of carbon dioxide. The captured carbon dioxide can be stored for further use, or sequestered permanently. The above method provides purified carbon dioxide for further use in agriculture and chemical processes, or for permanent sequestration.

An adsorption material is disclosed that comprises a metal-organic framework and a plurality of Hgands. The metal-organic framework comprising a plurality of metal ions. Each respective ligand in the plurality of ligands is amine appended to a respective metal ion in the plurality of metal ions of the metal-organic framework. Each respective ligand in the plurality of ligands comprises a substituted 1,3-propanediamine. The adsorbent has a CO2 adsorption capacity of greater than 2.50 mmol/g at 150 mbar CO2 at 40° C., Moreover, the adsorbent is configured to regenerate at less than 120° C. An example ligand is diamine 2,2-dimethyl-1,3-propane-diamine. An example of the metal-organic framework is Mg2(dobpdc), where dobpdc.sup.4− is 4,4′-dioxidobiphenyl-3,3′-dicarboxylate. Example applications for the adsorption material are removal of carbon dioxide from flue gas and biogasses.

An energy efficient and durable thermal swing type carbon dioxide recovery and concentration device can be made smaller and use low-temperature heat waste of 100 C. or less. A honeycomb rotor carries adsorption particles having a sorption capacity for carbon dioxide. The rotor is rotated in a sealed casing divided into at least an sorption zone and a desorption zone and is brought into contact with material gas that contains carbon dioxide in a state wherein the honeycombs in the sorption zone are moist so as to adsorb the carbon dioxide while carrying out evaporative cooling of water. Then, the honeycombs that have adsorbed the carbon dioxide are moved to the desorption zone and brought into contact with low pressure vapor so as to desorb high concentration carbon dioxide. Thus, it is possible to continuously recover carbon dioxide at a high recovery rate and high concentration.

Methods and systems directed to the separation of tritium from an aqueous stream are described. The separation method is a multistage method that includes a purification stage during which tritium of a tritium-contaminated aqueous stream is adsorbed onto a cooled and wet separation phase, a regeneration stage during which the adsorbed tritium is exchanged with hydrogen in a gaseous stream to regenerate the separation phase and provide a gaseous stream with a high tritium concentration, and a third stage during which the tritium of the gaseous stream is separated from the gaseous stream as a gaseous tritium product.

Compositions and methods of preparing the compositions are disclosed for sorbents and other surfaces that can adsorb and desorb carbon dioxide. A sorbent or surface can include a metal compound such as an alkali or alkaline earth compound and a support. The sorbent can be prepared by several methods, including an incipient wetness technique. The sorbents have a CO.sub.2 adsorption and desorption profile. A sorbent having high levels of a metal compound and adsorbed CO.sub.2 is disclosed.

A method for removing methoxyethanol from a mixture comprising methoxyethanol and morpholine makes use of the selective adsorption of methoxyethanol onto a mixed oxide comprising a spinel phase. The mixed oxide comprises 20 to 30% by weight MgO and 80 to 70% by weight Al.sub.2O.sub.3. The spinel phase has the formula MgAl.sub.2O.sub.4. The mixture is a pre-purified reaction output of the reaction of diethylene glycol with ammonia in the presence of an amination catalyst.

Sorbent materials that are treated with ions, salts, oxides, hydroxides, or carbonates of calcium, magnesium, strontium, or barium are useful in removing perfluoroalkyl and polyfluoroalkyl substances (PFAS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), 2,3,3,3,-tetrafluoro-2-(heptafluoropropoxy)propanoate and heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether, and similar compounds from liquids and gases are disclosed. The sorbent materials with the disclosed treatments offer improved performance as measured against untreated sorbent materials.