Coke Formation during Thermal Cracking of n-Octane

Abstract

Greek Letters B = aeration factor r = r function 0 = dimensionless time = m(GhdLM) p = viscosity, eq 32, g/cm s u = kinematic viscosity, eq 33, cm2/s p = density, g/cm3 or lb/ft3 u = surface tension, eq 32, dyn/cm u2 = dimensionless variance ut2 = time based variance, s2 4 = froth density factor on the tray $?Id = froth density factor in downcomer Literature CitedThe coking phenomenon as a function of temperature space time and surface to volume ratio ( s h ) of the 304 stainless steel reactor was investigated during pyrolysis of +octane in a tubular flow reactor. The experiments were carried out within the temperature range of 750-800 OC and space times up to about 1 s. The effect of surface treatments, namely air and H2S treatment, was studied. During all runs except those which were preceded by the H2S treatments, it was observed that in the beginning for about an hour the rate of coking was very high and after that it achieved a lower, steady-state value. The coking rates exhibited curious maxima with respect to the space times. Based on the rate data, reaction models for coking phenomena are proposed. The rate data are correlated by severity factor type correlations.

Anticoking Coatings for High Temperature Petrochemical Reactors

“…A literature survey showed that kinetic studies of coke formation have been hampered by an insufficient knowledge of the chemical pathways leading to coke and by a lack of reliable information concerning the reactivity of individual hydrocarbons: consequently, the models proposed for coke formation were mainly empirical [10][11][12][13].…”

Gas-phase reactions of chloroform and 1,1,2-trichloroethane with hydrogen in a tubular flow reactor

“…It has been suggested that the formation of aromatics, including benzene, results from reactions of acetylene and acetylenic species (Frenklach and Taki, 1983;Tanzana and Gardiner, 1980;Brockhorn et al, 1983). Virk et al (1972) have discussed a possible mechanism for coke formation from benzene, and the carbon formation from thermal cracking of hydrocarbons has also been reviewed by Froment (1981) and Shah et al (1976). Table I indicates that the formation of graphitic carbon oscillates with increasing temperature.…”

Combinatorial synthesis of carbon nanotubes by the catalytic chemical vapor deposition method

“…In each case the metal content of catalyst was 2.5-2.5 wt.% of iron and cobalt, respectively. The sources of metals were their acetate, acetyl-acetonate, and nitrate salts (Fe(CH 3 COO) 2 …”

“…At an early stage the main research activity aimed to avoid their formation [1,2], then, more and more researchers became familiar with special and valuable carbon forms such as carbon fibers [3,4], useful accumulation of hydrogen-rich coke depositions [5] or even carbon nanotubes [6,7].…”