Rumyantsev R.N.

SOLID-PHASE SYNTHESIS OF CALCIUM FERRITE WITH BROWNMILLERITE STRUCTURE

DOI: 10.6060/tcct.20165912.5495
Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2016. V. 59. N 12. P. 45-48

The process of calcium ferrite preparing from ferrum (II) oxalate and calcium hy-droxide by solid-phase interaction was studied using data of X-ray diffraction, X-ray phase analysis, simultaneous thermal analysis, and scanning electron microscopy. X-ray phase analysis results of a sample subjected to heat treatment at 750 °C for 3 h, show formation of single-phase brownmillerite structure of calcium ferrite Ca2Fe2O5. Analysis of the DTA shows that crystallization process continues up to 1000 °C. Calculation of substructure parameters of Ca2Fe2O5 shows that the area of coherent X-ray scattering is 198 Ǻ, total amount of mi-crostrains is 0.8 %. The specific surface area of the sample is not more 5 m2/g.

Key words: calcium ferrite, solid phase synthesis, brownmillerite structure

REFERENCES

2016, Т. 59, № 12, Стр. 45-48

OXIDATION OF METHANOL TO FORMALDEHYDE AT INDUSTRIAL CONDITIONS USING VARIOUS IRON-MOLYBDENUM CATALYSTS

The comparative analysis of operation results of two iron-molybdenum catalysts of foreign production F-1 and F-2 on an industrial large-capacity formaldehyde synthesis unit, consisting of two tubular reactors connected in series, was carried out. Variants of catalysts loading were presented and analysis of data on "hot spot" movement on the catalyst layer of the semi-annual period of reactors operation was carried out. The regularities of changes in the activity and selectivity of catalysts under consideration were examined at the beginning and end of the operation period.

Key words: methanol, formaldehyde, iron-molybdenum catalyst, activity, selectivity, tubular reactor

REFERENCES
1. Nakrokhin B.G., Nakrokhin V.B. The technology of pro-duction of formaldehyde from methanol. Novosibirsk. 1995. 444 p. (in Russian).
2. Ogorodnikov S.K. Formaldehyde. L.: Khimiya. 1984. 280 р. (in Russian).

2016, Т. 59, № 5, Стр. 65-71

INFLUENCE OF CALCIUM AND COPPER FERRITES ON ACTIVITY AND SELECTIVITY OF MEDIUM-TEMPERATURE CO CONVERSION CATALYSTS

Process of mechanochemical synthesis of calcium and copper ferrites was studied by X-ray and XRD analysis, thermogravimetry, IR spectroscopy and gas chromatography methods. Their high catalytic activity in reaction of carbon monoxide medium-temperature conversion by water vapour was shown. The composition of byproducts in the reaction of CO conversion and the concentration of impurities in condensate was calculated. The rheological properties of calcium and copper ferrites, as well as a catalyst on their basis, were studied.

Key words: calcium ferrite, copper ferrite, activity, selectivity, catalyst, carbon monoxide con-version

2016, Т. 59, № 3, Стр. 43-48
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