Abstract: Bi-metal nanoadsorbents and methods for their preparation and use are provided. Methods of using bi-metal nanoadsorbents to remove contaminants from samples, such as water, are also provided.

Abstract: A method and a system is provided for inactivation of Infectious Pancreatic Necrosis Virus (IPNV) comprising illuminating a liquid containing IPNV with a lamp emitting a continuous broad band of ultraviolet (UV) light. The UV lamp may be “tuned” to optimize IPNV inactivation. The lamp may be a medium pressure UV lamp that emits UV light having wavelength between 260-400 nm and preferably, between 260-300 nm. The pressure of the lamp may be greater than 1.6 bar, 3 bar and preferably is 7 bar. The lamp may be composed of PS (synthetic quartz).

Abstract: The present invention is a method of implementing Water Disinfection System employing a Functional Mixture, copper foam catalyst, continuous flow, UV radiation, and optical receiver pipe in order to inactivate broader range of microbial contaminants in drinking water, both for emergency purification kits and larger filtration systems. The Functional Mixture is formed when the portland cement (CaO—SiO2—Al2O3) and silicon dioxide (SiO2) combination is applied to the amalgamation of porous copper foam (Cu-Foam) and silver nitrate (AgNO3) particles, which react through the silver tree reaction (Cu+2AgNO3?2Ag+Cu(NO3)2) after spraying over a perforated mask. The high porosity Functional Mixture is placed in UV transmissive receiver pipe with optical properties. These configurations improve the coverage, efficiency, and effectiveness of reducing broader range of pathogenic microbes in water disinfection systems over prior art.

Abstract: A siphon trap disinfection unit consisting of a copper/silver electrode coated on inside body of the siphon parallel to each other along the siphon in the area which water normally stands. A water level sensor to generate resistance between two electrodes and an electric controller circuit to generate ions by applying voltage between two electrodes and controlling the amount of current passing through this control circuit to generate enough concentration of copper and silver ion continuously in the water standing area of the siphon trap to remove and deactivate harmful bacteria's in this area.

Abstract: According to one embodiment, an electrolytic membrane separation (EMS) subsystem is configured to remove one or more impurities from a contaminated reject solution and to recycle the reusable reject solution for subsequent use in regenerating ion exchange resins. According to another embodiment of the invention, the EMS subsystem is configured to concentrate the impurities recovered from the contaminated brine solution for subsequent disposal or treatment.

Abstract: An equipment for disposal of cyanobacteria in stagnant waters has a float structure, to which two types of bipolar electrodes (1 and 6) are mounted under the surface of water, interconnected and supplied with electric direct current via an alternator (10). The equipment comprises a supporting float (5) having the shape of a hollow body, in which there is a transversely positioned rib (4) with an attached suspended electrode (1), interconnected to supplies of photovoltaic cells (8) and alternator (10), fixed on the rib (4) there is the device (9) for utilizing wind power, connected to an alternator (10), driving the water pump (2), which is placed in the delivery pipe (3) and is connected directly to the axis of the device (9), for utilization of wind power. Fixed on the supporting float (5) there is the upper float (7) with the anchored grid electrode (6) and with the stored photovoltaic cells (8), interconnected with the electrodes (1) and (6).

Abstract: A hydromagnetic desalination cell including at least one hollow rectangular flow conduit, a first rectangular magnet and a second rectangular magnet each having a north pole face and a south pole face opposite of each other, wherein the first and second rectangular magnets are disposed along a longitudinal axis and on opposite sides of the rectangular flow conduit, a first opening and a second opening on opposite walls of the rectangular flow conduit extending between the first and second rectangular magnets, and a first and second chamber fluidly connected to the first and second openings. A hydromagnetic desalination system and methods of desalinating brine water with the hydromagnetic desalination system are also disclosed.

Abstract: A water treatment system includes a water mixing unit adapted to promote water turbulence, an input line having an upstream end adapted to be in fluid communication with a body of water to be treated, and a downstream end in fluid communication with the water mixing unit. The system includes an ozone injector adapted to be connected in fluid communication with an ozone gas generation system. A branching line is in fluid communication with the input line and the ozone injector and an ozone supply line is in fluid communication with the ozone injector and the input line. A bypass control valve is in fluid communication with the ozone supply line and the water input line and is adapted to be selectively switched between an open position and a closed position, wherein water is prevented from flowing through the branching line and the ozone supply line when the bypass control valve is in the closed position.

Abstract: Process for treating effluents containing nitrogen in ammonium form, using a sequential biological reactor (1), according to which: a volume of effluents to be treated in one complete cycle is introduced into the biological reactor in one or more successive fractions by volume, each fraction by volume being treated during a subcycle; each subcycle comprises a phase of feeding with a fraction by volume, and at least a first aerated step, during which total or partial oxidation of the ammonium to nitrites takes place by injection of air or of oxygen into the effluent, a settling out and emptying step taking place after the end of the complete cycle; the weight of N—NH4 to be treated is determined from the volume of effluents in the reactor at the end of the feeding phase, and from the difference between the initial N—NH4 concentration in the reactor and a concentration desired at the end of the aerated step, a maximum aeration time TM is dedicated to the aerated step, and an initial air flow rate Qairinit, for

Abstract: A water treatment system including an enclosure for water to be treated, a multiplicity of biomass carriers located within the enclosure, at least one airlift in the enclosure for raising the water and the biomass carriers and at least one mechanical biomass carrier accumulated residue removal apparatus operative to remove accumulated residue from the biomass carriers.

Abstract: A preparation method of Bacillus subtilis biological composite material loaded with Fe3O4 magnetic nanoparticles with core-shell structure includes the following steps: 1) preparation of Fe3O4 nanoparticles, 2) preparation of Fe3O4@mSiO2 nanoparticles, 3) preparation of Fe3O4@mSiO2@MANHE nanoparticles; and 4) preparation of Bacillus subtilis@Fe3O4@mSiO2@MANHE composite.

Abstract: The present invention relates to methods for preventing and/or reducing biofilm formation and/or planktonic proliferation with one or more selected bacteria strains or bacterial blends.

Abstract: A portable water recycling and treatment system and process for used and produced flowback frac water pumps the water from a collection tank through a series of dedicated hydration, retention and filtering tanks and vessels that provide treatment for the removal of chemicals, sediments and other containments. The system, which is enclosed, can be readily assembled on-site by interconnecting the dedicated tanks, vessels and pumps. The tanks and vessels may be situated in a plurality of trailers/units that are transported separately to the site.

Abstract: A wastewater recycling system includes a biological reactor having anaerobic, anoxic, and aerobic chambers. A lift station including a pump is operatively connected to the biological reactor. The lift station receives biologically treated liquid from the biological reactor and pumps the liquid from the lift station. A filtration subsystem is operatively connected to the lift station. The filtration subsystem receives and filters the liquid pumped by the lift station. The filtration subsystem includes a salt-rejecting membrane filter comprising a concentrate recirculation conduit operatively connected to recirculate salt-rejecting membrane filter concentrate to a point along the wastewater recycling system upstream of the salt-rejecting membrane filter, thereby forming a salt concentration loop between said point along the wastewater recycling system and the salt-rejecting membrane filter.

Abstract: A process and system for treating wastewater is described. The invention degrades sludge produced by treatment of the wastewater to reduce or eliminate the need for sludge dewatering and disposal. The invention also reduces the amount of nutrient additives required to sustain the aerobic wastewater treatment process. In one embodiment the invention includes the steps of (a) providing an aerobic treatment system receiving a supply of the wastewater; (b) treating a supply of the sludge to rupture microbial cells present therein to produce treated sludge having an increased liquid:solid ratio and an increased degradation potential in comparison to untreated sludge; (c) conveying a supply of the treated sludge to the aerobic treatment system; and (d) substantially degrading the supply of treated sludge in the aerobic treatment system. The treated sludge may optionally be subjected to anaerobic digestion prior to delivery to the aerobic treatment system.

Abstract: A waste stream is treated by anaerobic digestion. A process is described involves a step of separating solids from digestate, and returning separated solids to a digester. Optionally, there may be a step of solids separation in which larger solids are removed from the digester. A process and apparatus are described for treating waste sludge from a wastewater treatment plant in an anaerobic digester. Feed sludge is thickened or solids are separated from digestate and returned to the digester. Additional co-digestion waste may be added to the digester. The process and apparatus may be used in a retrofit of an existing wastewater treatment plant.

Abstract: The improved process for conditioning sludges by flocculation, according to which: the sludge to be treated is transported in a pipeline, at least one flocculating agent is inserted in the pipeline that transports the sludge to be treated, the sludge is then mixed with the said flocculating agent. finally, the mixture is transported and then discharged in a natural or an artificial excavation at a distance from the bottom of the said excavation that is less than its depth.

Abstract: A flexible ribbon configuration includes a flexible glass ribbon including a leading end and a trailing end. In one example, the flexible ribbon configuration includes at least one ribbon extension extending between a first end and an opposing second end. In another example, the first end of the ribbon extension is attached to at least one of the trailing end and the leading end of the flexible glass ribbon. In yet another example, the at least one ribbon extension defines an elongated opening between the first end of the ribbon extension and the second end of the ribbon extension. Further examples include a method of making a flexible ribbon configuration. Still further examples include a method of separating a flexible ribbon configuration.

Abstract: A bottle cutter has a body having two generally arcuate components connected to each other by straight parallel members permitting one component to slide relative to the other component between an open, non-cutting position and a closed, cutting position. Each arcuate component includes a plurality of an inwardly facing rollers that facilitate rotation of a bottle held by the bottle cutter in the closed, cutting position. A cutting wheel disposed on one of the two components cuts, or at least scores, the bottle as the bottle is rotated. If the bottle is only scored, separation of the top and bottom portions of the bottle may be effected using hot and cold water to induce differential thermal stresses in the glass. The edge may be finished or polished using sandpaper or any other suitable abrasive material.

Abstract: A lift device for lifting a glass sheet in a glass processing system includes a lift jet array having peripheral lift jet outlets and inner lift jet outlets disposed inwardly of the peripheral lift jet outlets. Furthermore, each lift jet outlet is operable to allow gas to flow toward the glass sheet. The lift device also includes a control unit for controlling operation of the lift jet outlets, and the control unit is configured to commence operation of at least one of the inner lift jet outlets prior to commencing operation of at least one of the peripheral lift jet outlets.

Abstract: A tempered glass of the present invention includes, as a glass composition, in terms of mass %, 45 to 75% of SiO2, 0 to 30% of Al2O3, and 0 to 30% of Li2O+Na2O+K2O and has a ?-OH value of 0.3 to 1/mm.

Abstract: A silicate glass that is tough and scratch resistant. The toughness is increased by minimizing the number of non-bridging oxygen atoms in the glass. In one embodiment, the silicate glass is an aluminoborosilicate glass in which ?15 mol %?(R2O+R?O—Al2O3—ZrO2)—B2O3?4 mol %, where R is one of Li, Na, K, Rb, and Cs, and R? is one of Mg, Ca, Sr, and Ba.

Abstract: Glass and glass ceramic compositions having a combination of lithium silicate and petalite crystalline phases along with methods of making the glass and glass ceramic compositions are described. The compositions are compatible with conventional rolling and float processes, are transparent or translucent, and have high mechanical strength and fracture resistance. Further, the compositions are able to be chemically tempered to even higher strength glass ceramics that are useful as large substrates in multiple applications.

Abstract: A composition for forming a conductive film includes at least one of a metal salt (A1) and a metal particle (A2) as component (A) that serves as a metal source of the conductive film, and a metalloxane compound (B). The metal salt (A1) and the metal particle (A2) contain one or more metals selected from the group consisting of Ni, Pd, Pt, Cu, Ag, and Au. The metalloxane compound (B) has at least one metal atom selected from the group consisting of Ti, Zr, Sn, Si, and Al in its main chain. Preferably, the metal salt (A1) is a carboxylate containing a metal selected from the group consisting of Cu, Ag, and Ni. Preferably, the metal particle (A2) has an average particle diameter of 5 nm to 100 nm and comprises a metal selected from the group consisting of Cu, Ag, and Ni.

Abstract: A method for producing an oxynitride film includes: (A) supplying a first precursor containing a network former into a reactor in which a substrate is placed; (B) supplying at least one of an oxygen gas and an ozone gas into the reactor; (C) supplying a second precursor containing at least one of an alkali metal element and an alkaline-earth metal element into the reactor; (D) supplying at least one of a nitrogen gas and an ammonia gas into the reactor; and (E) supplying a purge gas into the reactor.

Abstract: The present disclosure relates to a device and a method for baking a substrate. The device includes a hot plate, and a supporting member for supporting a substrate to be processed, wherein the supporting member is located between the hot plate and the substrate to be processed, and can move relative to the hot plate so as to adjust the contacting position of the supporting member with the substrate to be processed. With the device, the yield of the substrate can be increased.

Abstract: The invention relates to a substrate (30) coated on one face (31) with a multilayer of thin films (34) comprising at least one metal functional layer (140) based on silver or made of silver and two antireflective coatings (120, 160), the said antireflective coatings each comprising at least one antireflective layer (124, 164), the said functional layer (140) being disposed between the two antireflective coatings (120, 160), characterized in that the said metal functional layer (140) is a discontinuous layer having a surface area occupation factor in the range between 50% and 98%, or even between 53% and 83%.

Abstract: A method is provided for treating the outer surfaces of a plurality of glass bubbles. That method includes loading a plurality of glass bubbles into a processing vessel having a roughened lining and displacing the processing vessel so that the plurality of glass bubbles move against the roughened lining to thereby roughen the outer surfaces. Alternatively, or in addition, the glass bubbles are subjected to air plasma treatment to increase the surface energy of the glass bubbles.

Abstract: Magnesium phosphate cement binder systems and method for providing magnesium phosphate cements are described. In an embodiment, a magnesium phosphate cement binder system may include magnesium oxide that has been calcined at a temperature of between about 900° F. to about 1800° F. The magnesium phosphate cement binder system may also include a phosphate material. Other formulations, compositions, and methods are also described.

Abstract: The invention relates to a method for producing an expanded granulate from sand grain-shaped mineral material (1) with a propellant, wherein the material (1) is fed into a vertically upright furnace (2) from above and said material (1) falls along a drop section (4) through multiple heating zones (5) in a furnace shaft (3) of the furnace (2), wherein each heating zone (5) is heatable using at least one independently controllable heating element (6), and the material (1) is heated to a critical temperature at which the surfaces (7) of the sand grains (15) plasticize and the sand grains (15) are expanded by the propellant.

Abstract: The invention relates to use of nano-fibrillar cellulose as an gas-entrainment stabilizer, which when used in cementitious materials, provides improved gas pore structure quality and/or stability and/or robustness with regard to water content variation. The invention further relates to a method for stabilizing gasentrainment of cementitious materials and to a method for providing cementitious material with improved air pore structure quality and/or stability and/or robustness with regard to water content variation.

Abstract: An omniphobic aqueous stain repellant integral grout additive contains an aminoalkyl-substituted polyorganosiloxane, preferably, a higher alkyl alkoxysilane, an organopolysiloxane T resin bearing silicon-bonded alkoxy groups, a fluoro(meth)acrylate polymer or copolymer, and preferably, a film forming (meth)acrylate polymer or copolymer latex. The omniphobic grout additive provides high stain repellancy to grout in an economic manner.

Abstract: A refractory, coarse ceramic product including at least one granular refractory material, has an open porosity of between 22 and 45 vol.-%, in particular of between 23 and 29 vol.-%, and a grain structure of the refractory material, wherein the medium grain size fraction with grain sizes of between 0.1 and 0.5 mm is 10 to 55 wt.-%, in particular 35 to 50 wt.-%, and wherein the remainder of the grain structure is a finest grain fraction with grain sizes of up to 0.1 mm and/or coarse-grain fraction with grain sizes of more than 0.5 mm.

Abstract: A dielectric material having a rutile crystalline structure includes Ti as a major constituent metal element, and, as metal elements other than Ti, a metal element M1 which includes at least one selected from among Ni, Co, and elements belonging to Group 2 according to a periodic table, and a metal element M2 which includes at least one selected from among elements belonging to Group 5 and Group 6 in the periodic table, and, on a basis of a total amount of Ti, the metal element M1, and the metal element M2, a molar ratio x of the metal element M1 is in a range of 0.005 to 0.025 and a molar ratio y of the metal element M2 is in a range of 0.010 to 0.050.

Abstract: A refractory object may include a zircon body that may include at least about 0.1 wt. % and not greater than about 5.5 wt. % of an Al2O3 containing component for a total weight of the zircon body. The zircon body may further include at least about 25 wt. % and not greater than about 35 wt. % of a SiO2 component for a total weight of the zircon body.

Abstract: A method of preparing a fine powder of calcium lanthanoid sulfide is disclosed. The method includes spraying soluble calcium and lanthanoid salts into at least one precipitating solution to form a precipitate comprising insoluble calcium and lanthanoid salts, optionally, oxidizing the precipitate comprising insoluble calcium and lanthanoid salts, and sulfurizing the optionally oxidized precipitate to form a fine powder of calcium lanthanoid sulfide. An alternative method for forming the powder is by flame pyrolysis. The calcium lanthanoid sulfide powder produced by either method can have an impurity concentration of less than 100 ppm, a carbon concentration of less than 200 ppm, a BET surface area of at least 50 m2/g, and an average particle size of less than 100 nm.

Abstract: Biochar is provided that is treated to have certain chemical and physical properties found to have the highest impact on plant growth and/or soil health. In particular, the following physical and/or chemical properties, among others, of a biochar have been identified as critical properties to control for in the selection of biomass feedstock, pyrolysis conditions, and/or enhancing treatment to increase biochar performance: (i) bulk density (ii) impregnation capacity; (iii) particle size distribution; (iv) solid particle density; (v) surface area; (vi) porosity; (vii) total porosity; (viii) ratio of macroporosity to total porosity (ix) content of residual organic compounds; (x) content of volatile organic compounds; (xii) ash content; (xiii) water holding capacity; (xiv) water retention capabilities; (xv) levels of dioxins and other potentially hazardous byproducts of pyrolysis; and (xvi) pH.

Abstract: A composition based on three strains of microorganisms to promote plant growth and serve as a plant protection product to protect plants from damaging influences including plant disease, pests or insects. The composition is comprised of isolated strains of Paenibacillus polymyxa M10, Azospirillum canadense B2, and Bacillus pumilus L13. A mineral mix is used to maintain the microorganism viable for a long time, maintaining high efficacy as a biopesticide and biofertilizer. The mineral mix combined with the fermented microorganisms is then further combined with a nutritional additive to enhance the biofertilizing and biopesticidal features of the composition. The resulting composition can be applied to plants in liquid form or to the soil in solid form.

Abstract: Process for transformation of a feedstock of lignocellulosic biomass and/or the carbohydrates, into mono-oxidized or poly-oxidized compounds, wherein the feedstock is contacted, simultaneously, with a catalytic system that comprises one or more homogeneous catalysts selected from Brønsted acids and heterogeneous catalysts comprising at least one metal selected from groups 6 to 11 and 14 of the periodic table, and a substrate selected from perovskites of formula ABO3, in which A is Mg, Ca, Sr, Ba, and La, and B is selected from Fe, Mn, Ti and Zr, oxides of lanthanum, neodymium, yttrium, cerium, and niobium, or mixtures thereof, and mixed oxides of aluminates of zinc, copper, and cobalt, or mixtures thereof, in the same reaction chamber, with at least one solvent, being water or water with at least one other solvent, under reducing atmosphere, and temperature of 50° C. to 300° C., and pressure of 0.5 MPa to 20 MPa.

Abstract: Methods are provided for improving the yield of aromatics during conversion of oxygenate feeds. An oxygenate feed can contain a mixture of oxygenate compounds, including one or more compounds with a hydrogen index of less than 2, so that an effective hydrogen index of the mixture of oxygenates is between about 1.4 and 1.9. Methods are also provided for converting a mixture of oxygenates with an effective hydrogen index greater than about 1 with a pyrolysis oil co-feed. The difficulties in co-processing a pyrolysis oil can be reduced or minimized by staging the introduction of pyrolysis oil into a reaction system. This can allow varying mixtures of pyrolysis oil and methanol, or another oxygenate feed, to be introduced into a reaction system at various feed entry points.

Abstract: The invention relates to a hydrocarbon conversion process and a reactor configured to carry out the hydrocarbon conversion process. The hydrocarbon conversion process is directed to increasing the overall equilibrium production of ethylene from typical pyrolysis reactions. The hydrocarbon conversion process can be carried out by exposing a hydrocarbon feed to a peak pyrolysis gas temperature in a reaction zone in the range of from 850° C. to 1200° C.

Abstract: A catalyst for producing monocyclic aromatic hydrocarbons of 6 to 8 carbon number from a feedstock oil having a 10 volume % distillation temperature of at least 140° C. and an end point temperature of not more than 400° C., or a feedstock oil having a 10 volume % distillation temperature of at least 140° C. and a 90 volume % distillation temperature of not more than 360° C., wherein the catalyst contains a crystalline aluminosilicate, gallium and/or zinc, and phosphorus, and the amount of phosphorus supported on the crystalline aluminosilicate is within a range from 0.1 to 1.9% by mass based on the mass of the crystalline aluminosilicate; and a method for producing monocyclic aromatic hydrocarbons, the method involving bringing a feedstock oil having a 10 volume % distillation temperature of at least 140° C. and an end point temperature of not more than 400° C., or a feedstock oil having a 10 volume % distillation temperature of at least 140° C.

Abstract: An apparatus and method are provided for processing hydrocarbon feeds. The method may pass a pyrolysis feed to a thermal pyrolysis reactor and expose at least a portion of the pyrolysis feed to high-severity operating conditions in a thermal pyrolysis reactor, wherein the thermal pyrolysis reactor is operated at operating conditions that include pressure ?36 psig and provide a reactor product that has a C3+ to C2 unsaturate weight ratio ?0.5.

Abstract: A process for the isomerization of a para-xylene depleted, meta-xylene rich stream under at least partially liquid phase conditions using ZSM-23 with an external surface area of at least 75 m2/g (indicating a small crystallite size), and a SiO2/Al2O3 ratio between 15 and 75 that produces a higher than equilibrium amount of para-xylene, i.e., more than about 24 wt % of para-xylene, based on the total amount of xylenes.

Abstract: A process for aromatizing hydrocarbons comprises: converting at least a portion of highly branched hydrocarbons in a feed stream into selectively convertible components, and aromatizing the selectively convertible components to produce an aromatization reactor effluent. The aromatization reactor effluent comprises an aromatic product. Converting at least the portion of the highly branched hydrocarbons into the selectively convertible components may include contacting the feed stream with an isomerization catalyst in an isomerization reaction system under isomerization reaction conditions; and isomerizing the portion of the highly branched hydrocarbons in the feed stream into the selectively convertible components.

Abstract: A method for producing a conjugated diolefin is configured as follows. A monoolefin having four or more carbon atoms is fed from a plurality of monoolefin feed nozzles. In addition, at least 50% or more of a total amount of an oxygen-containing gas is fed from an oxygen-containing gas feed nozzle located at a bottom of a fluidized bed reactor. Furthermore, the plurality of monoolefin feed nozzles at n places located at heights a1, a2, . . . , and an from the oxygen-containing gas feed nozzle, respectively, feed the monoolefin having four or more carbon atoms at ratios of b1, b2, . . . , bn (b1+b2+ . . . +bn=1), respectively. Furthermore, a weighted mean value represented by the following formula is 100 mm or greater: weighted mean value=a1*b1+a2*b2+ . . . +an*bn.

Abstract: A process is presented for the production of butadienes. The process includes the recovery of a crude butadiene stream using adsorption separation and removes the need to compress the effluent stream from the oxidative dehydrogenation process effluent stream. The process includes an adsorption step to remove C4 compounds from the oxidative effluent stream, a desorption step to recover the adsorbed C4 compounds and a regeneration step to regenerate the adsorbent for continued use in the separation process.

Abstract: Processes for the production of olefins are disclosed, which may include: contacting a hydrocarbon mixture comprising linear butenes with an isomerization catalyst to form an isomerization product comprising 2-butenes and 1-butenes; contacting the isomerization product with a first metathesis catalyst to form a first metathesis product comprising 2-pentene and propylene, as well as any unreacted C4 olefins, and byproducts ethylene and 3-hexene; and fractionating the first metathesis product to form a C3? fraction and a C5 fraction comprising 2-pentene. The 2-pentene may then be advantageously used to produce high purity 1-butene, 3-hexene, 1-hexene, propylene, or other desired products.

Abstract: The present invention relates to a method for obtaining high purity (bromomethyl)cyclopropane and (bromomethyl)cyclobutane, starting respectively with cyclopropylmethanol and cyclobutylmethanol, under synthesis conditions that enable high productivity and high yield.

Abstract: A method for producing a tetrafluoroolefin, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), comprises dehydrofluorinating a pentafluoroalkane in a gas phase in the presence of a catalyst comprising chromium oxyfluoride. In a preferred embodiment, 2,3,3,3-tetrafluoropropene (HFO-1234yf) is produced by forming a catalyst comprising chromium oxyfluoride by calcining CrF3.xH2O, where x is 1-10, in the presence of a flowing gas comprising nitrogen to form a calcined chromium oxyfluoride, and dehydrofluorinating 1,1,1,2,2-pentafluoropropane (HFC-245cb) in a gas phase in the presence of the catalyst to form the 2,3,3,3-tetrafluoropropene (HFO-1234yf).