Mechanism of formation of hydantoins
Hydantoins, (I), are biologically active compounds which occur in nature and have been isolated from such sources as sugar beets and butterfly wings. Synthetic analogs have found widespread use as anticonvulsant drugs, bacteriocides, stabilizers in photographic film, and in the preparation of high temperature epoxy resins. Uses, preparation, and reactions of hydantoins have been extensively studied and are reported elsewhere. Recently a number of hydantoin isomers have been detected and identified in coal gasification condensate water from the gasification of Indian Head (ND) lignite in a slagging fixed bed gasifier. The hydantoins constitute a major portion of the organics in the condensate water. In generation the concentrations of hydantoins found in the condensate water from an ash gasifier are smaller than those found from the slagging process. Lignite coal reacting in a slagging gasifier gives the largest concentration of hydantoins in the condensate water. The major isomer in the coal gasification condensate water is 5,5-dimethylhydantoin (DMH). DMH is formed from individual species (acetone, cyanide, ammonia, and carbonate) in the condensate water and does not form directly in the gasifier. The rate of formation of DMH was first order in all of the reactants as expressed by the equation: Rate of formation of DMH = (Acetone) (HCN) (NH/sub 3/) (CO/sub 2/). This kinetic data is valuable in predicting the rate of formation of DMH in coal gasification condensate water, provided the model is applicable. A mechanism consistent with the kinetic data and partially verified by others is shown in Scheme 1. 13 refs.
- Research Organization:
- North Dakota Univ., Grand Forks (USA). Energy Research Center
- DOE Contract Number:
- FC21-83FE60181
- OSTI ID:
- 6000912
- Report Number(s):
- DOE/FE/60181-164; CONF-860425-20; ON: DE86008929
- Country of Publication:
- United States
- Language:
- English
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The mechanism of the formation of hydantoins
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Related Subjects
010404* -- Coal
Lignite
& Peat-- Gasification
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
AZOLES
CHEMICAL ANALYSIS
COAL GASIFICATION PLANTS
HETEROCYCLIC COMPOUNDS
HYDANTOINS
HYDROGEN COMPOUNDS
IMIDAZOLES
INDUSTRIAL PLANTS
LIQUID WASTES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
SYNTHESIS
WASTE WATER
WASTES
WATER