2 edition of Chromium recovery from high-temperature shift Cr-Fe catalysts found in the catalog.
Chromium recovery from high-temperature shift Cr-Fe catalysts
A. M. Stubbs
|Statement||by A.M. Stubbs and B.W. Jong ; with an appendix on process economics by M.J. Magyar.|
|Series||Report of investigations (United States. Bureau of Mines) -- 9204.|
|Contributions||Jong, B. W.|
|LC Classifications||USBMRI9204 1988|
|The Physical Object|
|Pagination||10 p. :|
|Number of Pages||10|
|LC Control Number||88-600220|
84 Fe, 8 Cr, 4 Cu, 4 Ce 74 Fe, 15 Al, 8 Cr, 4 Cu 88 Fe, 8 Cr, 4 Cu Small amounts of added alumina or ceria produce higher rates and more thermally stable high temperature water gas shift catalysts compared to conventional iron oxide/chromia/copper Reaction conditions: g catalyst; °C h, °C 16 h; H 2O:CO = 3; H The preparation of modern catalysts involves the addition of a small amount of water to a potassium and iron oxide mixture. The iron oxide mixture is then extruded to form 4 to 6 mm diameter pellets. 7 These pellets are dried and heated to a high temperature ~geoffrey-price/Courses/ChE.
Chromium is the 22nd most abundant element in Earth's crust with an average concentration of ppm. Chromium compounds are found in the environment, due to erosion of chromium-containing rocks and can be distributed by volcanic eruptions. The concentrations range in soil is between 1 and mg/kg, in sea water 5 to µg/liter, and in rivers and recovery process. Various active catalyst systems have been reported for the SO2 reduction by CO. Most studied are alumina-supported transition metals and oxides (such as Cu, Fe, Mn, Cr, Ni, Pd, Ag and others) [6,7]. Production of COS usually proceeds to a substantial extent on these catalysts and water partially poisons the catalyst
Copper promoted iron/chromium based high temperature shift (HTS) catalyst with ultra-low hexavalent chromium levels. SSK TK SiliconTrap™ is a NiMo catalyst with very high rates for removal of metals (Ni, V, Fe) and silicon. Shape-optimized guard material used for protecting shift catalysts from dust and other :// high-temperature service, strength at temperature is related to time at temperature. Allowable Deformation Another factor to consider in designing for high-temperature service is the amount of deformation that can be permitted during the total service life. This factor determines which of two high-temperature strength properties
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Chromium Recovery From High. Temperature Shift Cr-Fe Catalysts By A. Stubbs and B. Jong With an Appendix on Process Economics by M. Magyar UNITED STATES DEPARTMENT OF THE INTERIOR Donald Paul Hodel, Secretary BUREAU OF MINES T Additional Physical Format: Online version: Stubbs, A.M.
Chromium recovery from high-temperature shift Cr-Fe catalysts. Pittsburgh, PA: U.S. Dept. of the Interior The Bureau of Mines has devised a procedure to selectively extract and recover chromic oxide (cr2o3) from waste high-temperature shift catalysts that contain approximately 6 pct cr and 62 pct fe, both in oxide :// Chromium recovery from high-temperature shift Cr-Fe catalysts.
The chromium from the leach liquor was recovered utilizing an oxidation-reduction reaction with ph adjustment to form a hydrous chromic oxide (2o) precipitate. The roast-leach procedure produced chromium extractions greater than pct, with product recovery in excess The effects of different precursors for CuO on the catalytic properties of Fe-Cr-based CO high-temperature shift (HTS) catalyst were investigated.
It was shown that CuO improved low-temperature activity Chromium recovery from high-temperature shift Cr-Fe catalysts book the catalyst and doping of CuO as copper nitrate was High Temperature Shift Catalyst(HTS) The typical composition of commercial HTS catalyst is normally Fe/Cr/Mg composed.
The chromium acts to stabilize the iron oxide and prevents sintering. The operation of HTS catalysts occurs within the temperature range of The water gas shift reaction is one of the oldest heterogeneous catalytic reactions operating in industry for H 2 production with high purity and CO removal from syngas.
Typical industrial catalyst for high temperature water gas shift (HTS) reactions is Fe–Cr–Cu, but has environmental and safety concerns related to chromium content, which has been regarded as a hazardous In its purest form, chromite ore contains 68% Cr 2 O 3, and Cr:Fe ratio of Louis Nicolas Vauquelin was the discoverer of the element “chromium,” and named the mineral “ferrous-chromate-alumine” in Later, Wilhelm Haidinger named it “chromite” in with reference to its extremely high chromium :// Commercially, the low-temperature WGS (LT-WGS) reaction is performed at ∼− °C with a Cu/ZnO/Al 2 O 3 catalyst, and the high-temperature WGS (HT- WGS) reaction is performed at ∼− °C with a Cu promoted chromium-iron mixed oxide catalyst.
There are also a variety of noble metal catalysts being developed and exhibit A large effect on the reduction time was observed by increasing the temperature from 1 K to 1 K for pellets without Fe-Si addition: around 4 times faster at 1 K than at 1 K for reaction fraction close to one.
However, when the temperature was further increased from 1 K to 1 K the kinetics improved by ://?q=Ferro-chromium. Using a high temperature shift (HTS) catalyst based reactor or a series of HTS Sulfur is a poison for Fe-Cr catalysts.
LTS reactors are copper based catalyst. Typical compositions include Cu, Zn, Cr and Al Fe 2O 3/ Cr 2O 3 Commercial reduced particle size - ,9 0,93 0,24 -0,31 0,00 Bohlbro et :// In this paper, we report a detailed characterisation of chromium doped iron oxide catalysts using a range of techniques to establish the nature of chromium species in the near surface and bulk of iron oxide, high-temperature shift (HTS) particular we have employed X-ray absorption spectroscopy Cr K-edge near edge and extended fine structure data for )“Cr- and Ce-Doped Ferrite Catalysts for the High-Temperature Water-Gas Shift Reaction: TPR and Mossbauer Spectroscopy l of Physical Chemistry C,G.K.
Reddy, and P.G. Smirniotis ()Effect of Copper as a Promoter on Cr- and Ce-based Ferrite Catalysts for the High-Temperature WGS :// Abstract. A series of supported CrO 3 /Fe 2 O 3 catalysts were investigated for the high-temperature water-gas shift (WGS) and reverse-WGS reactions and extensively characterized using in situ and operando IR, Raman, and XAS spectroscopy during the high-temperature WGS/RWGS reactions.
The in situ spectroscopy examinations reveal that the initial oxidized catalysts Scheme 1 summarizes the research progress on Cr-free Fe-Al-Cu catalysts described in previous works.
Specifically, our group has extensively investigated Fe-based catalysts to improve their performance for the conversion of waste-derived synthesis gas, screening a number of additives for the target reaction [11,12,40,41].As a result, we developed a promising Fe Fe-Cr-Cu catalysts are typical industrial catalysts for high temperature water gas shift reaction but have environmental and safety concerns related to chromium :// A series of supported CrO 3 /Fe 2 O 3 catalysts were investigated for the high-temperature water-gas shift (WGS) and reverse-WGS reactions and extensively characterized using in situ and operando IR, Raman, and XAS spectroscopy during the high-temperature WGS/RWGS reactions.
The in situ spectroscopy examinations reveal that the initial oxidized catalysts contain surface dioxo (O=) 2 Cr A laboratory powder X-ray diffraction pattern showed that crystalline phase had been produced, isostructural with the chromium carboxylate MIL(Cr) Elemental analysis indicated that the contents of Fe, F, C and H (obs: % Fe, % F, % C) are › 百度文库 › 互联网.
Chromium-promoted iron catalysts are normally used in the first stage high temperature reactions (referred to as a high temperature shift or HTS reaction) to effect carbon monoxide conversion at temperatures above about ° C.
and to reduce the CO content to about 3%–4% (see, for example, D. Newsom, Catal. Rev., 21, p. ()) The excretion & whole-body retention of various (51)Cr chromium compounds differed greatly in the rat & mouse.
Thus, 7 days after the iv dose to mice, retained (51)Cr was 2% of Cr-EDTA, 20% of Cr-alloxantin, 40% of chromium chloride, & nearly % of chromium trihydroxide. There was high uptake of chromium trihydroxide in the ://. Removal of hexavalent chromium had attracted much attention as it is a hazardous contaminant.
An electrocoagulation-like technology electro-reduction was applied. The chromium (VI) in the wastewater was reduced to chromium (III) by the electron supplied by electricity power and Fe2+, formed from corrosion of steel electrodes in acidic :// Then g of spent iron-chrome high temperature shift catalyst of the type described in our U.S.
application, Ser. No.and containing % w/w of iron oxide (calculated as Fe 2 O 3), % w/w of Cr 2 O 3, was added in powder form. The slurry was digested at ° F. under refluxing conditions for two The kinetics of the water-gas shift (WGS) over three newly developed chromium-free catalysts Fe2O3/ZrO2, Rh/ZrO2, and Rh/Fe2O3/ZrO2 were investigated in a parallel six