Abstract: Processes for producing butadiene from n-butane comprising: (a) providing a feed gas stream comprising n-butane; (b) non-oxidatively dehydrogenating the feed gas stream in the presence of a catalyst in a first dehydrogenation zone to form a first intermediate gas stream comprising n-butane, 1-butene, 2-butene, butadiene and hydrogen; (c) oxidatively dehydrogenating the first intermediate gas stream in the presence of an oxygenous gas having an oxygen content of at least 75% by volume in a second dehydrogenation zone to form a second intermediate gas stream comprising n-butane, butadiene, hydrogen, carbon dioxide and steam; (d) compressing and cooling the second intermediate gas to form a first condensate stream comprising water and a third intermediate gas stream comprising n-butane, butadiene, hydrogen, carbon dioxide and steam; (e) compressing and cooling the third intermediate gas to form a second condensate stream comprising n-butane, butadiene and water and a fourth intermediate gas stream comprising n-b

Abstract: A process for preparing butadiene from n-butane, comprising the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to obtain a product gas stream b comprising n-butane, 1-butene, 2-butene, butadiene, hydrogen and low-boiling secondary constituents, with or without carbon oxides and with or without steam; C) feeding the product gas stream b of the nonoxidative catalytic dehydrogenation and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating n-butane, 1-butene and 2-butene to obtain a product gas stream c comprising n-butane, 2-butene, butadiene, low-boiling secondary constituents, carbon oxides and steam, said product gas stream c having a higher content of butadiene than product gas stream b; D) removing the low-boiling secondary constituents and steam to obtain a C4 product gas stream d substantially

Abstract: A process for preparing butadiene from n-butane, comprising the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively, catalytically dehydrogenating n-butane to obtain a gas stream b comprising n-butane, 1-butene, 2-butene, butadiene and hydrogen, with or without steam, with or without carbon oxides and with or without inert gases; C) feeding the gas stream b and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to obtain a gas stream c comprising n-butane, butadiene, hydrogen, steam, with or without carbon oxides and with or without inert gases; D) compressing in at least one first compression stage and cooling the gas stream c to obtain at least one condensate stream d1 comprising water and a gas stream d2 comprising n-butane, butadiene, hydrogen and steam, with or without carbon oxides and with or without inert gase

Abstract: A process for preparing butadiene from n-butane, comprising the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively, catalytically dehydrogenating n-butane to obtain a gas stream b comprising n-butane, 1-butene, 2-butene, butadiene and hydrogen, with or without carbon dioxide and with or without steam; C) feeding the gas stream b and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to obtain a gas stream c comprising n-butane, butadiene, hydrogen, carbon dioxide and steam, D) compressing in at least one first compression stage and cooling the gas stream c to obtain at least one condensate stream d1 comprising water and a gas stream d2 comprising n-butane, butadiene, hydrogen, carbon dioxide and steam, E) separating the gas stream d2 by extractive distillation into a product stream e1 consisting substantially of but

Abstract: A process for preparing maleic anhydride by oxidizing n-butane in the gas phase under heterogeneous catalysis with oxygen-containing gases over a vanadium-, phosphorus- and oxygen-containing catalyst in a reactor unit at a temperature in the range from 350 to 500° C., removing the maleic anhydride formed to form a gas stream which comprises unconverted n-butane and water and recycling at least a portion of the unconverted n-butane to the reactor unit, by feeding to the reactor unit an inlet stream having an n-butane concentration of from 0.5 to 1.5% by volume and an oxygen concentration of from 5 to 21% by volume, establishing a pressure at the inlet to the reactor unit of from 0.4 to 2 MPa abs, and converting from 40 to 100% of the n-butane from the inlet stream per reactor pass.

Abstract: Processes for producing butadiene from n-butane comprising: (a) providing a feed gas stream comprising n-butane; (b) non-oxidatively dehydrogenating the feed gas stream in the presence of a catalyst in a first dehydrogenation zone to form a first intermediate gas stream comprising n-butane, 1-butene, 2-butene, butadiene and hydrogen; (c) oxidatively dehydrogenating the first intermediate gas stream in the presence of an oxygenous gas having an oxygen content of at least 75% by volume in a second dehydrogenation zone to form a second intermediate gas stream comprising n-butane, butadiene, hydrogen, carbon dioxide and steam; (d) compressing and cooling the second intermediate gas to form a first condensate stream comprising water and a third intermediate gas stream comprising n-butane, butadiene, hydrogen, carbon dioxide and steam; (e) compressing and cooling the third intermediate gas to form a second condensate stream comprising n-butane, butadiene and water and a fourth intermediate gas stream comprising n-b

Abstract: The invention relates to a process for preparing butadiene from n-butane having the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to obtain a product gas stream b comprising n-butane, 1-butene, 2-butene, butadiene, hydrogen, low-boiling secondary constituents and in some cases steam; C) feeding the product gas stream b of the nonoxidative catalytic dehydrogenation and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to obtain a product gas stream c comprising n-butane, 2-butene, butadiene, hydrogen, low-boiling secondary constituents and steam, said product gas stream c having a higher content of butadiene than the product gas stream b; D) removing hydrogen, the low-boiling secondary constituents and steam to obtain a C4 product gas stream d substantially consisting of n-

Abstract: The invention relates to a process for preparing butadiene from n-butane having the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to obtain a product gas stream b comprising n-butane, 1-butene, 2-butene, butadiene, hydrogen, low-boiling secondary constituents and in some cases steam; C) feeding the product gas stream b of the nonoxidative catalytic dehydrogenation and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene to obtain a product gas stream c comprising n-butane, 2-butene, butadiene, hydrogen, low-boiling secondary constituents and steam, said product gas stream c having a higher content of butadiene than the product gas stream b; D) removing hydrogen, the low-boiling secondary constituents and steam to obtain a C4 product gas stream d substantially consisting of

Abstract: The invention relates to a process for preparing butadiene from n-butane having the steps of A) providing a feed gas stream a comprising n-butane; B) feeding the feed gas stream a comprising n-butane into at least one first dehydrogenation zone and nonoxidatively catalytically dehydrogenating n-butane to obtain a product gas stream b comprising n-butane, 1-butene, 2-butene, butadiene, hydrogen, low-boiling secondary constituents and in some cases steam; C) feeding the product gas stream b of the nonoxidative catalytic dehydrogenation and an oxygenous gas into at least one second dehydrogenation zone and oxidatively dehydrogenating n-butane, 1-butene and 2-butene to obtain a product gas stream c comprising n-butane, 2-butene, butadiene, low-boiling secondary constituents and steam, said product gas stream c having a higher content of butadiene than the product gas stream b; D) removing the low-boiling secondary constituents and steam to obtain a C4 product gas stream d substantially consisting of n-butane, 2-

Abstract: A process for preparing a vanadium, phosphorus, and oxygen catalyst precursor for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms, which comprises (a) reacting vanadium pentoxide with from 102 to 110% strength phosphoric acid in the presence of a primary or secondary, noncyclic or cyclic, unbranched or branched, saturated alcohol having from 3 to 6 carbon atoms in a temperature range from 80 to 160° C.; (b) isolating the precipitate formed; (c) setting an organic carbon content of ?1.1% by weight in the isolated precipitate by heat treatment in a temperature range from 250 to 350° C., the heat-treated product, following the addition of 3.0% by weight of graphite, giving a powder X-ray diffraction diagram which in the 2? region features a ratio of the height of the peak of any pyrophosphate phase present at 28.5° to the height of the peak due to the graphite at 26.6° of ?0.

Abstract: A process for preparing a vanadium, phosphorus, and oxygen catalyst precursor for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms, by reacting vanadium pentoxide (I) in the presence of a primary or secondary, noncyclic or cyclic, unbranched or branched, saturated alcohol having from 3 to 6 carbon atoms (II) with a pentavalent or trivalent phosphorus compound (III) in a temperature range from 80 to 160° C. with stirring and subsequently filtering the resultant suspension, in which (a) the way in which the phosphorus compound (III) and the vanadium pentoxide (I) are combined in the presence of the alcohol (II), (b) the action of a stirring power of from 0.01 to 0.6 W/kg suspension, and/or (c) the filtration at a temperature from 65° C. to 160° C.

Abstract: A biological indicator for monitoring the effectiveness of a sterilizing, disinfecting, etc., compound or condition is disclosed which comprises a substrate having a surface layer containing functional groups thereon desirably free of silicone linking groups. The functional groups are desirably in the form of a monolayer of a uniformed distribution and of a selected quantity. Various types of microorganisms such as spores and/or etiological agents are covalently bonded to the surface layer functional groups through a crosslinking reagent and thus form a uniform number and distribution of the microorganisms and/or etiological agents. After being subjected to sterilization or other similar treatment, etc., along with various articles such as instruments, the indicator can be cultivated to determine the effectiveness of the sterilization, disinfection, etc. process.

Abstract: A process for preparing maleic anhydride by oxidizing n-butane in the gas phase under heterogeneous catalysis with oxygen-containing gases over a vanadium-, phosphorus- and oxygen-containing catalyst in a reactor unit at a temperature in the range from 350 to 500° C., removing the maleic anhydride formed to form a gas stream which comprises unconverted n-butane and water and recycling at least a portion of the unconverted n-butane to the reactor unit, by feeding to the reactor unit an inlet stream having an n-butane concentration of from 0.5 to 1.5% by volume and an oxygen concentration of from 5 to 21% by volume, establishing a pressure at the inlet to the reactor unit of from 0.4 to 2 MPa abs, and converting from 40 to 100% of the n-butane from the inlet stream per reactor pass.

Abstract: A method of charging a vertical tube having an internal diameter of 50 mm or less with catalyst particles, which comprises introducing a filling aid into the vertical tube, where the filling aid comprises a flexible elongated body and the ratio of the cross section of the flexible elongated body to the cross section of the tube is from 0.003 to 0.08, and introducing the catalyst particles into the tube.

Abstract: In a belt splicer, having crossbeams straddling over and under the splice area, and having tie-bolts holding the ends of the crossbeams together, the safety system comprises link-spacers which link the crossbeams together. The link-spacers are profiled complementarily to the crossbeams, whereby the link-spacers can slide relative to the crossbeams. If a tie-bolt should fail, the cross-beams are held in place, relative to the other crossbeams, by the link-spacers.

Abstract: A process for coating internals in a reactor, except for the coating of electrically heatable, at least partly open-cell foams, with a catalytically active material or a precursor thereof is described, in which an aerosol which contains, as a disperse phase, the catalytically active material or the precursor thereof is provided and the aerosol is passed through the reactor at a velocity which is established so that the disperse phase of the aerosol is deposited on the internals in the reactor.

Abstract: Process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of hydrocarbons having at least four carbon atoms by means of oxygen-containing gases at from 350 to 500° C.

Abstract: Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance 1n at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to ?5° C.

Abstract: A new and improved EGR valve having a valve body having an inlet port and an outlet port with a valve member moveably supported within the valve body between the inlet and outlet ports. A control cap is connected to the valve body and contains an integrated sensor that is used to provide an engine control module with pressure readings from the valve body and the interior portion of the cap. Additionally the cap also has an integrated zero emissions system that is capable of preventing the release of harmful chemicals into the atmosphere.

Abstract: A process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of an n-butene-containing hydrocarbon stream by means of oxygen-containing gases in a shell-and-tube reactor having two successive reaction zones, where the first, feed-side reaction zone contains at least one catalyst which is suitable for the oxydehydrogenation of n-butenes to 1,3-butadiene and the second, product-side reaction zone contains at least one catalyst which is suitable for the oxidation of 1,3-butadiene to maleic anhydride, is carried out using a shell-and-tube reactor which has at least one heat transfer medium circuit in the region of the first, feed-side reaction zone and at least one further heat transfer medium circuit in the region of the second, product-side reaction zone.