Synthesis of low molecular weight olefins over coprecipitated iron-manganese catalysts. Volume VIII. Final report. [C/sub 2/-C/sub 4/ olefins]
The synthesis of low molecular weight olefins (C/sub 2/-C/sub 4/) from hydrogen and carbon monoxide has been investigated over unsupported iron-manganese catalysts. Nine iron-manganese catalysts with different atomic ratios were prepared by coprecipitation of Mn/Fe iron and manganese nitrates. Atomic absorption spectroscopy was used to determine the catalyst compositions. The catalysts were evaluated in a conventional bench-scale fixed bed reactor system. A period of 12 hours was generally required to stabilize the activity and selectivity of the iron-manganese catalysts at the operating conditions investigated: 473 to 483 K temperature, 1465 kPa pressure, 2/1:H/sub 2//CO ratio, and 1.08 cm/sup 3/g/sup -1/s/sup -1/ reactant gas space velocity. No evidence of catalyst deactivation was detected during the deactivation experiments up to forty hours on stream. A catalyst reduction study with these iron-manganese catalysts was carried out in a thermogravimetric analysis system. A reduction in flowing hydrogen at 673 K and at the ambient pressure for 8 hours was found to be sufficient to activate the catalyst for the carbon monoxide hydrogenation reaction. The hydrogen pretreatment resulted in a relatively more stable pattern of catalyst activity, higher selectivity for C/sub 2/-C/sub 4/ hydrocarbons and lower total production of carbon dioxide and methane. The experimental results of the carbon monoxide hydrogenation at the standard catalyst evaluation conditions over a series of iron-manganese catalysts indicated that the catalyst activity generally decreased as the manganese concentration of the catalyst increased; however, the C/sub 2/-C/sub 4/ olefin selectivity was significantly enhanced in the presence of a small amount of manganese in the catalyst. 86 refs., 35 figs., 22 tabs.
- Research Organization:
- Utah Univ., Salt Lake City (USA). Dept. of Fuels Engineering
- DOE Contract Number:
- AC22-79ET14700
- OSTI ID:
- 5331316
- Report Number(s):
- DOE/ET/14700-T1-Vol.8; ON: DE85014173
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010404 -- Coal
Lignite
& Peat-- Gasification
090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
ALKENES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISORPTION
COMPARATIVE EVALUATIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
FISCHER-TROPSCH SYNTHESIS
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGENATION
INFORMATION
IRON
LOW PRESSURE
MANGANESE
MEDIUM PRESSURE
MEDIUM TEMPERATURE
METALS
METHANATION
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRESSURE DEPENDENCE
REDUCTION
RESEARCH PROGRAMS
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SPECIFICITY
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS