Liang et al. / J Zhejiang Univ SCI 2005 6B(6):590-596
A study on naphtha catalytic reforming reactor
simulation and analysis
LIANG Ke-min (梁克民)†1, GUO Hai-yan (郭海燕)1, PAN Shi-wei (潘世伟)2
(1School of Petrochemical Engineering, Shenyang University of Technology, Liaoyang 111003, China)
(2School of Advanced Professional Technology, Shenyang University of Technology, Liaoyang 111003, China)
Received Sept. 22, 2004; revision accepted Dec. 17, 2004
Abstract: A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe
the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic
reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and
aromatic groups by single compounds. The simulation results based above models agree very well with actual operation unit data.
Key words: Naphtha, Catalytic reforming, Kinetics, Simulation and analysis
doi:10.1631/jzus.2005.B0590 Document code: A CLC number: TE624.42
Catalytic reforming of naphtha or mixture of
naphtha with a certain amount of cracking oil is a
process of great interest to the petrochemical industry
for the production of aromatic compounds that are
raw materials for plastics, elastomers and resins
manufacture. Catalytic reforming unit uses naphtha or
cracking oil as feedstock to produce rich aromatic
compounds and high octane value liquid products
through reactions such as aromatization, cyclization,
and hydrocracking. At the same time, it produces
hydrogen (H) and liquified petroleum gas (LPG) as its
by-products. The design or simulation of the catalytic
reforming reactor is very difficult because of com-
plicated components of catalytic reforming feedstock,
higher operating temperature of the system, and the
complicated reactions in the reactor.
Much research (Pontes et al., 1999) on this
subject had been carried out. Results have been pub-
lished on the process, reactions and kinetics. A con-
ventional naphtha catalytic reforming unit consists of
3 or 4 radial flow reactors in series operated under
adiabatic conditions. The temperature and the H2/HC
molar ratio are the most important process variables.
A bifunctional catalyst with Pt and a second metal is
generally used. In addition, some novel processes
(Melnikov and Makarova, 1998; Smith, 1960; Bolz et
al., 1999) of catalytic reforming had been developed.
The kinetics of catalytic reforming has been at-
tracting the attentions of many researchers. A suc-
cessful kinetic analysis proposed by Smith (1959),
was based on idealizing the complex naphtha mixture
by representing the paraffin, naphthene, and aromatic
groups by single compounds. The nature of the re-
forming reactions in which the number of carbon
atoms was the same for the precursor and product
justified this procedure. Reaction rates were derived
from the assumption of a homogeneous system.
Jorge and Eduardo (2000) proposed a lumped
kinetic model for the naphtha catalytic reforming
process. The model utilizing lumped mathematical
representation of the reactions taking place was in
terms of isomers of the same nature. Arrhenius-type
variation was added to the model in order to include
the effect of pressure and temperature on the rate
constants. Many other kinetic models (Jerzy, 1999)
are not described here.
Journal of Zhejiang University SCIENCE
Liang et al. / J Zhejiang Univ SCI 2005 6B(6):590-596
460100 300 500 700 900
Bed radius (mm)
Fig.5 The temperature distribution of reforming radial
Data at inlet
Data at outlet
1. The three assumptions in the present model
are reasonable. The results indicate that the
one-dimensional homogenous model is suitable for
describing catalytic reforming radial flow reactor.
2. Once pseudo ingredients were selected suita-
bly. The present empirical kinetics model can be well
applied to catalytic reforming reactor for simulation
3. This method can be used to predict aromatic
capacity, yield, transformation rate, bed temperature,
and so on for new operation conditions. Therefore, the
optimum operating parameters can be obtained to
yield maximum profit.
Bolz, C.R., Graziani, K.R., Harandi, M.N., Ozawa, Y.,
Sorensen, C.M., 1999. Radial-Flow Reactors Containing
Multiple Catalyst Beds, Especially for Naphtha Reform-
ing and Upgrading. PCT Int. Appl. WO 9920384.
there was more catalyst in the inlet where the reac-
tants content was higher than that at the outlet.
Therefore, more aromatic compounds were generated
and more heat was absorbed at the inlet side. The
situation at the outlet side was totally opposite. For
reactor III and IV in spite of the trend being similar to
that of reactors I and II, the temperature varied more
gently because the reactions were exothermic.
For comparison, the reactors calibration values
are also shown in Fig.5. The simulation results and
actual values of the reforming product are shown in
Table 6. These results indicate that the model and
simulation in the present paper are satisfactory.
Jerzy, S., 1999. On the kinetics of catalytic reforming with the
use of various raw materials. Energy Fuels, 13(1):29-39.
Jorge, A.J., Eduardo, V.M., 2000. Kinetic modeling of naphtha
catalytic reforming reactions. Energy Fuels, 14(5):
Lu, H., 1982. Manual of Petrochemical Industry Fundamental
Data. Chemical Industy Press, Beijing (in Chinese).
Melnikov, V.B., Makarova, N.P., 1998. Modification of re-
forming: Without hydrogen circulation. Khim. Tekhnol.
Topl. Masel., 23(1):9-13.
Pontes, L.A.M., Rangel, M.D.C., Mario, D.J.M., 1999. Cata-
lytic reforming of naphtha. An Assoc. Bras. Quim.,
Rase, H.F., 1977. Chemical Reactor Design for Process Plants.
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Reid, R.C., Prausnitz, J.M., Sherwood, T.K., 1977. The Prop-
erties of Gases and Liquids. 3rd Ed., McGraw-Hill Co.,
Smith, R.B., 1959. Kinetic analysis of naphtha reforming with
platinum catalyst. Chem. Eng. Progr., 55(6):76-80.
Smith, R.B., 1960. Reforming of Naphtha in Several Stages. U.S.
2, 965, 560.
Yong, W., 1995. Calibration of E603 reforming catalyst.
Liaohua Sci. and Tech., 16(4):16-19.
Table 6 Comparison between actual values of reforming product and simulation results
Flow rate of products (kg/h)
Depentane oil Arene
Actual (Yong, 1995)
Simulation 15580.96 11258.49
Error (%) −0.026
Productivity of arene