The present invention provides that powder is mainly constituted from secondary particles of hydroxyapatite. The secondary particles are obtained by drying a slurry containing primary particles of hydroxyapatite and aggregates thereof and granulating the primary particles and the aggregates. A bulk density of the powder is 0.65 g/mL or more and a specific surface area of the secondary particles is 70 m.sup.2/g or more. The powder of the present invention has high strength and is capable of exhibiting superior adsorption capability when it is used for an adsorbent an adsorption apparatus has.

A method for separating mixed xylene includes steps that the mixed xylene is subjected to adsorption separation by means of an adsorbent having a metal organic framework material, so that one or more of xylene isomers are separated out. An organic ligand in the metal organic framework material is 2,5-dihydroxy-1,4-benzoquinone. Xylene isomers can be effectively separated using this method.

The invention relates to a process for removing and recovering mercury, an impurity, from a hydrocarbon feedstream containing oxygen, such as introduced during hydraulic fracturing. Mercury is selectively removed to very low levels of concentration from fluid streams such as natural gas, cracked gas, hydrogen or naphtha by passage of the stream through an adsorbent bed containing particles of a zeolitic molecular sieve preferably having pore diameters of at least 3.0 angstroms and in which the zeolite crystallites are formed into an aggregate (cylindrical or beads) which contain ionic or elemental silver. These adsorbent particles maintain their capacity for removal of mercury despite the presence of oxygen.

Improved processes and systems for sweeping an activated carbon bed after steam regeneration to decrease or prevent the occurrence of flameouts or unit trips in a reaction furnace of a low-pressure sulfur recovery unit. The improved sweeping process includes conveying a sweeping gas to the reaction furnace at a sweeping flow rate that is less than an operational flow rate of the activated carbon bed. The improved system includes a bypass line that bypasses at least a portion of the main outlet line of the activated carbon bed to result in a reduced sweeping flow rate. The improved sweeping process may include starting the sweeping process after the temperature of the active carbon beds drops below a threshold level.

A process for separating 1-butene from a C4 raffinate gas composition includes introducing the C4 raffinate gas composition to a reactor containing an adsorbent material and passing the C4 raffinate gas composition through the adsorbent material; adsorbing the 1-butene from the C4 raffinate gas composition onto the adsorbent material to separate the 1-butene from the C4 raffinate gas composition and form a residue gas composition; and desorbing the 1-butene by heating the adsorbent material after the adsorbing to form the 1-butene and regenerate the adsorbent material. The adsorbent material is at least one of a zeolite adsorbent and an alkali-modified zeolite adsorbent having at least 99% by weight selective towards 1-butene for adsorption in comparison to iso-butene and iso-butane.

The present invention provides that powder is mainly constituted from secondary particles of hydroxyapatite. The secondary particles are obtained by drying a slurry containing primary particles of hydroxyapatite and aggregates thereof and granulating the primary particles and the aggregates. A bulk density of the powder is 0.65 g/mL or more and a specific surface area of the secondary particles is 70 m.sup.2/g or more. The powder of the present invention has high strength and is capable of exhibiting superior adsorption capability when it is used for an adsorbent an adsorption apparatus has.

A continuous chromatography system includes a plurality of treatment columns, each column of the plurality of columns including an adsorbent. The system further includes a valve system configured to operate the plurality of columns as a simulated moving bed system. The valve system includes a first valve configuration having an injection of a brine into a first column of the plurality of columns and an extraction of an eluate from a second column of the plurality of columns. The second column being a different column than the first column. The valve system further includes a second valve configuration comprising a recirculation of fluid through the plurality of columns.

Embodiments of systems and methods for producing a coated activated carbon comprise the steps of providing activated carbon particles having a particle size up to about 100 m, and coating the activated carbon particles by spraying droplets of a cationic polymer solution onto the surface of the activated carbon particles, wherein the cationic polymer solution comprises about 1% to about 15% by weight cationic polymer and the droplet size is between about 5 m to about 100 m.

The invention in its various embodiments is directed to methods and equipment for generating an activated sorbent from a sorbent precursor with the addition of certain chemicals that enhance the effectiveness of the activated sorbent. The invention in its various embodiments is also directed to the methods and equipment for generating some of the chemicals that are added to the raw carbonaceous material or activated sorbent to enhance its effectiveness. The invention in its various embodiments is also directed to methods and equipment for generating certain chemicals that can be added to a gas stream to convert a given gaseous pollutant to a form that is more easily removed from the gas stream.

An adsorption-desorption material, in particular, crosslinked organo-amine polymeric materials having a weight average molecular weight of from about 500 to about 110.sup.6, a total pore volume of from about 0.2 cubic centimeters per gram (cc/g) to about 2.0 cc/g, and an adsorption capacity of at least about 0.2 millimoles of CO.sub.2 adsorbed per gram of adsorption-desorption material, and linear organo-amine polymeric materials having a weight average molecular weight of from about 160 to about 110.sup.6, a total pore volume of from about 0.2 cubic centimeters per gram (cc/g) to about 2.0 cc/g, and an adsorption capacity of at least about 0.2 millimoles of CO.sub.2 adsorbed per gram of adsorption-desorption material. This disclosure also relates in part to processes for preparing the crosslinked organo-amine materials and linear organo-amine materials. This disclosure further relates in part to the selective removal of CO.sub.2 and/or other acid gases from a gaseous stream containing one or more of these gases using the adsorption-desorption materials.