Scaling up of naphtha cracking coils

Abstract

Science, Columbia University, 1979. Literature CitedAggenbach, P. De Rovij, A. H. Neth. Appl. 7009685, 1972. APHA, "Standard Methods for the Examination of Water and Waste Water," 13th ed.; 1975. pp 237 for a, 211 for b, 96 for c. ; Regnier, J.; Miquel, P.: Talllard, D. Report CEACONF-1903CEACONF- (1974). Patigny, P.; Regnbr, J.; Miquel, P.; Taillard, D. Roc. Inst. Solvent Extr. Conf. 1974, 3, 2019. Ralney, R. H. Nucl. Appl. 1965, 7(4), 310. Richardson, G. L.; Swanson. J. L. Report HEW-TME-7531 (1975). Schlee. C. S.; Caverly, M. R.; Henry, H. E.; Jenklns, W. J. USAEC Report Schulre, R. German Offen. 692412, 1940. Swanson, J. L.The paper presents experimental data on naphtha cracking in a pilot plant and discusses three ways of approach for scaling up naphtha-cracking coils. The first, direct experimental simulation, is not sufficiently accurate if the conversion is to be predicted, since complete similarity between industrial-, pilot-, and benchgcale units is bnpossible. The second approach is based upon the equivalent space time VE/Fo. It is shown that, for a given dilution, there is a unique relation between VE/Fo and the naphtha conversion. The corresponding product distribution is obtained from graphs or correlations derived from essentially isobaric small-scale experimentation. Since the product yiekls depend upon partial and total pressure and since in commercial cracking these vary along the coil, the selection of an average value for the total and partial pressure inevitably leads to some error In the predicted product distribution. The third approach makes use of a detailed mathematical model to simulate the cracking operation. The model contains a number of rate equations which can be derived from bench and pilot-scale experimentation. The model generates the conversion, product yiekls, temperatwe, and pressure profiles along the reactor. Exce#ent agreement between simulated and measured values is arrived at for the cracking of a heavy naphtha in an Industrial reactor.The conversion of dibenzothiophene to the corresponding sulfoxide and sulfone by the action of chlorine and water was studied. The effects of temperature, reaction time, and solvent on the yield of these products and on the concurrent ring chlorination of dibenzothiophene were examined. Slurry-phase chlorination of dibenzothiophene in water at 70 O C was found to be an excellent method for the preparation of the sulfone.

Investigating the effect of key factors, their interactions and optimization of naphtha steam cracking by statistical design of experiments

“…Temperature increases steadily in order to increase the selectivity index but it does not reach to its upper bound, because the methane yield increases sharply beyond a conversion of 85% that have seen in our results (not included) and the other researchers [2,23]. Methane yield has a significant effect on the severity index along with ethylene and propylene.…”

Thermal cracking of JP-10: Kinetics and product distribution

“…The equivalent reactor volume, V E , is defined as the volume that, at a chosen equivalent temperature, T E , and reference pressure P E , would give the same conversion as the actual reactor with its temperature and pressure profile. For a first-order reaction with negligible pressure drop in the reactor, V E can be expressed as [8],…”

Multivariable optimization of thermal cracking severity

“…Then, a tradeoff exists between the plant throughput and the frequency of the down times and, thus, an optimum figure should exist for ω. To this complexity, one can add the nonlinear behavior of the yields of propylene, butene, butadiene and gasoline along the reactor coil as demonstrated in Lichtenstein (1964), Chambers and Potter (1974a), Froment et al (1976), Szepesy (1980), Van Damme et al (1981), Van Camp et al (1984), Van Camp et al (1985), and Van Geem et al (2005) as a consequence of the temperature profile and the coil geometry. Then, oversimplification must be avoided in order to assure an optimal set-point collection of the three process variables employed in this research.…”