Thermal reactions of aromatics with CaO. Final report. [1-Methylanthracene, 9-methylanthracene]
The pyrolysis of benzene, toluene, 1-methylnaphthalene, 1-methylanthracene, 9-methylanthracene, m-cresol, and n-heptane was studied over CaO and quartz in a fixed-bed reactor under atmosphere pressure. The reaction temperature spanned the range of 350 to 900/sup 0/C with vapor phase residence time kept between 1 and 2 seconds. Compared to quartz, CaO significantly increased the rates and extents of pyrolysis of the aromatic hydrocarbons, reducing the temperature for a given amount of conversion by at least 100/sup 0/C. The magnitude of this enhancement effect increased with increasing aromaticity, or molecular size, of the compounds. For the light aliphatic, n-heptane, the effect of CaO is minor, with pyrolysis results similar to those observed over quartz and in vapor phase cracking. Coke was the major product for pyrolysis of aromatic compounds over either solid. Detailed examination of the distribution of the volatile products suggests that: (1) condensation reactions were the major pyrolysis reactions over CaO, and (2) some of the active sites on the CaO surface may be related to anion defects in the CaO lattice. CaO deactivation studies show that coke deposits from pyrolysis quickly destroy the CaO activity. Oxygen burnoff of the coke at temperatures between 650 and 800/sup 0/C regenerated 70 to 80% of the initial CaO activity. Pyrolysis of m-cresol on CaO surfaces exhibited acid-base behavior over the temperature range 0 to 550/sup 0/C. The initial pyrolysis rate was rapid but formation of calcium salts of cresol, which have much larger molar volumes than the substrate limited the accessibility of reactant gas to the inner unreacted surface, thus drastically reducing the overall rate of conversion with increasing stone utilization. At temperatures above 550/sup 0/C, these calcium salts decomposed to yield coke, CO, H/sub 2/O and other light hydrocarbon gases. 20 refs., 26 figs., 4 tabs.
- Research Organization:
- Massachusetts Inst. of Tech., Cambridge (USA)
- DOE Contract Number:
- FG22-80PC30229
- OSTI ID:
- 5994964
- Report Number(s):
- DOE/PC/30229-7; ON: DE85010688
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal reactions of aromatics with CaO. Technical progress report, September 1, 1980-April 30, 1981. [Compounds tested -1-methylnaphthalene, toulene, benzene, n-heptane]
Thermal reactions of aromatics with CaO. Technical progress report, September 1, 1982-March 31, 1983. [l-methylnaphthalene]
Related Subjects
010406 -- Coal & Coal Products-- Pyrolysis & Cracking-- (-1987)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKALINE EARTH METAL COMPOUNDS
ALKANES
ALKYLATED AROMATICS
ANTHRACENE
AROMATICS
ATMOSPHERIC PRESSURE
BENZENE
CALCIUM COMPOUNDS
CALCIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COKE
CONDENSED AROMATICS
CRESOLS
DATA
DEACTIVATION
DECOMPOSITION
EXPERIMENTAL DATA
HEPTANE
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
METHANE
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHENOLS
POLYCYCLIC AROMATIC HYDROCARBONS
PYROLYSIS
QUARTZ
RESEARCH PROGRAMS
SILICON COMPOUNDS
SILICON OXIDES
THERMOCHEMICAL PROCESSES
TOLUENE
VERY HIGH TEMPERATURE
WATER
YIELDS