A method for manufacturing a carbon dioxide adsorbent includes preparing an amine aqueous solution having an amine compound concentration ranging from 5% to 70% inclusive and a temperature ranging from 10 C. to 100 C. inclusive, impregnating silica gel with the amine aqueous solution, and aeration-drying the silica gel carrying the amine compound. The silica gel has a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, and a pore volume ranging from 0.1 cm.sup.3/g to 1.3 cm.sup.3/g inclusive.

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.

As an improvement to processes for desulfurization of natural gas and synthetic natural gas streams that employ conventional zeolitic materials (absorbents), including copper-containing zeolites, pre-treatment methods and post-treatment methods are provided that lower the level of leachable benzene following desulfurization with the absorbents to <0.5 mg benzene/L leachate, while retaining within the absorbents a majority of sulfur adsorbed from a gas stream.

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.

The present invention relates to a process for capturing carbon dioxide from a gas stream. The gas stream is contacted with solid adsorbent particles in an adsorption zone. The adsorption zone has at least two beds of fluidized solid adsorbent particles, and the solid adsorbent particles are flowing downwards from bed to bed. The solid adsorbent particles comprise 15 to 75 weight % of organic amine compounds. The gas stream entering the adsorption zone has a dew point which is at least 5 C. below the forward flow temperature of the coolest cooling medium in the adsorption zone. Carbon dioxide enriched solid adsorbent particles are heated, and then regenerated. The desorption zone has at least two beds of fluidized solid adsorbent particles, and the stripping gas is steam. The regenerated particles are cooled and recycled to the adsorption zone.

A method and system are disclosed for regenerating carbonaceous adsorbent, the method comprising the steps of: a) providing a carbonaceous adsorbent comprising a catalyst and adsorbed contaminants, b) pyrolysing of the adsorbed contaminants, c) reactivating the carbonaceous adsorbent by subjecting the carbonaceous adsorbent to steam thereby obtaining a reactivated carbonaceous adsorbent, d) cooling the thus obtained reactivated carbonaceous adsorbent to a temperature of less than 250? C. and e) oxidizing catalyst that is in a reduced state following steps b) and c) comprised in the reactivated carbonaceous adsorbent.

An adsorption material is disclosed that comprises a metal-organic framework and a plurality of ligands. 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 CO.sub.2 adsorption capacity of greater than 2.50 mmol/g at 150 mbar CO.sub.2 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-propanediamine. An example of the metal-organic framework is Mg.sub.2(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.

There is provided an active coke regeneration mixed vapor treatment method. The method comprises the following process steps of: A) performing a first water condensation on a mixed vapor produced during an active coke regeneration process by spray water in a first condensation zone; B) performing a second water condensation on the mixed vapor that is after the first water condensation by spray water in a second condensation zone, to further condensate and purify the mixed vapor; C) eliminating moisture in a gas through mist elimination from the gas fraction in the mixed vapor that is after the second water condensation, and discharging the remaining gas from the upper of the second condensation zone; and, D) discharging active coke micro powder in the mixed vapor that is after the second water condensation, with condensation water. In the present invention, an apparatus for implementing the abovementioned method is also provided.

A process for regenerating an adsorbent for nitrogen-containing compounds present in a hydrocarbon feed comprising contacting the adsorbent with an inert gas at a temperature in the range of from 10 to 60 C., followed by contacting the adsorbent with an inert gas at an elevated temperature in the range of from 200 to 260 C. and cooling the adsorbent in an inert gas.

There are provided herein methods and systems for increasing efficiency in a multi-stage activated carbon system. The methods and systems provide a cleaned carbon solids fraction and a waste liquor from wet air regeneration, and direct the same to a second stage and a first stage, respectively, of the multi-stage activated carbon system to enhance removal efficiency therein.