Passivation of iron catalysts for ammonia synthesis

Journal Article · Thu Nov 01 04:00:00 EST 1984 · Sov. Chem. Ind. (Engl. Transl.); (United States)

OSTI ID:5290638

Chesnokova, R V; Minaev, D M; Vasilevich, A A; Kuznetsov, L D; Alekseev, A M; Mishchenko, Sh Sh

At the present time, the practical interest in passivation of iron ammonia synthesis catalyst results from production of catalyst in reduced form and also from the need for passivation of catalysts during temporary shutdowns of synthesis columns in order to maintain the activity of the catalyst. The spent catalyst also must be passivated prior to offloading, in order to avoid combustion upon contact with air. In all of these cases, the need for passivation of reduced ammonia synthesis catalysts is connected with the pyrophoric character of the iron. It has been established that the pyrophoric character is eliminated after an oxide layer of a specific thickness has been applied to the surface of the iron - i.e., after passivation. To resolve the problems of recovering spent catalyst with controllable depth of oxidation, tests were carried out on low-temperature oxidation of catalysts in the 50-200/sup 0/C temperature interval. This article presents the results of a study of the oxidation of iron on a sample of reduced magnetite and on samples of various industrial ammonia synthesis catalysts (types SA-1, SA-1V and SAMV-5) at 50, 100, 150 and 200/sup 0/C with oxygen from mixtures of oxygen and helium (oxygen concentrations 0.1, 1.0 and 3.0 vol%) under dynamic conditions. 9 references, 3 figures, 4 tables.

• OSTI ID: 5290638
• Journal Information: Sov. Chem. Ind. (Engl. Transl.); (United States), Journal Name: Sov. Chem. Ind. (Engl. Transl.); (United States) Vol. 16:11; ISSN SVCIA
• Country of Publication: United States
• Language: English

Related Subjects

090320* -- Inorganic Hydrogen Compound Fuels-- Preparation-- (1976-1989)
10 SYNTHETIC FUELS
AMMONIA
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HELIUM
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IRON
LOW TEMPERATURE
METALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
NUMERICAL DATA
OXIDATION
OXYGEN
PASSIVATION
PRODUCTION
RARE GASES
TRANSITION ELEMENTS