Skip to main content
SpringerLink
Log in

Effect of the nonuniformity of the inlet liquid distribution on the trickle-bed reactor output in an exothermic reaction accompanied by evaporation

  • Published:
Theoretical Foundations of Chemical Engineering Aims and scope Submit manuscript

Abstract

The effect of the inlet liquid distribution on the operation of a trickle-bed reactor is experimentally investigated, and the observed phenomena are analyzed using a one-dimensional mathematical model with nonequilibrium approaches to describing phase transitions. The modeling shows that, if the fraction of the wetted surface at the reactor inlet is below unity, then, along a sufficiently long bed, there is always a stationary front of complete evaporation and complete conversion. The main conclusion within the framework of the considered one-dimensional model with separate evaporation (on completely wetted granules) and gas-phase hydrogenation (on dry granules) is that safe operation (the absence of a thermal explosion) can be ensured by complete suppression of the reaction in the gas phase.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

A:

absolute output, g/s

c g :

specific heat of the gas mixture, J/(kg K)

c ℓ :

specific heat of the liquid, J/(kg K)

D:

reactor diameter, mm

D AB :

binary diffusion coefficient of components A and B, m2 s

D AH :

binary diffusion coefficient of components A and H, m2 s

D 0 :

effective diffusion coefficient of the vapor of component A, m2 s

d eq :

equivalent diameter of intergranular channels for the gas

d p :

diameter of catalyst granules, m

f:

surface fraction of the wetted catalyst

G g :

gas mass flow rate per total cross section, kg/(m2 s)

G ℓ :

liquid mass flow rate per total cross section, kg/(m2 s)

ΔH evA , ΔH evB :

enthalpy changes in the phase transitions of α-methylstyrene and cumene, respectively, J/mol

K:

liquid flow rate, g/s

L:

length of the reactor or the catalyst bed, mm

L tz :

trickling zone length, mm

m H, m A, m B :

molar masses of hydrogen, α-methylstyrene, and cumene, respectively, kg/mol

N A, N B :

phase transition rates of α-methylstyrene (A) and cumene (B), respectively, mol/(m2 s)

N AB = N A + N B :

total phase transition rate, mol/(m2 s)

P:

total pressure, N/m2

P*A, P*B :

saturation vapor pressures of α-methylstyrene and cumene, respectively, N/m2

Q:

heat of gas-phase hydrogenation, J/mol

Q evA , Q evB :

heat of phase transitions for α-methylstyrene (A) and cumene (B), respectively, J/mol

R:

gas constant, J/(mol K)

S:

specific geometric surface area of the granular bed, m−1

S sp :

specific mass surface area of the catalyst, m2/g

T Ab = 438.5 K, T Ac = 654 K, P Ac = 33.6 bar, T Bb = 425.6 K, T Bc = 631 K, P Bc = 31.7 bar:

boiling points (subscript b) and critical temperatures and critical pressures (subscript c) for α-methylstyrene (A) and cumene (B)

T i :

temperature (i = g, ℓ, s), °C

T in :

temperature at the reactor inlet, °C

U H, U A :

linear velocities of hydrogen and α-methylstyrene, respectively, cm/s

W g :

gas-phase reaction rate, mol/(m2 s)

X:

α-methylstyrene conversion, %

x i :

mass fractions of components in the gas (i = A, B, H)

x ℓi :

mass fractions of components in the liquid (i = A, B)

y*A, y*B, y*H :

equilibrium mole fractions of components A, B, and H2, respectively, in the gas at the boundary with the liquid and the wetted granules

y i :

mole fractions of components in the gas (i = A, B, H)

y li :

mole fractions of components in the liquid (i = A, B)

z:

coordinate along the catalyst bed length, mm

αg :

heat-transfer coefficient between the gas and the catalyst surface, W/(m2 K)

αSL :

heat-transfer coefficient between the dry and wetted surfaces of granules, W/(m2 K)

βAH, β*:

mass-transfer coefficients between the gas and the wetted surface of granules, m/s

βgS :

mass-transfer coefficient between the gas and the dry surface of granules, m/s

γ:

porosity

ɛ:

fraction of the evaporated liquid

λg :

thermal conductivity of the gas mixture, W/(m K)

λH, λA :

thermal conductivities of hydrogen and α-methylstyrene, respectively, W/(m K)

λp :

thermal conductivity of catalyst granules, W/(m K)

λS :

longitudinal thermal conductivity on dry granules, W/(m K)

μ:

gas dynamic viscosity, kg/(m s)

μl :

liquid viscosity, kg/(m s)

ρl :

liquid density, kg/m3

σ:

liquid surface tension, N/m

ϕ:

liquid volume fraction in the intergranular space

ϕ = ϕdyn + ϕstat :

liquid fraction in the free volume of the granular bed as the sum of dynamic and static components

ω:

volume output, mol/(m3 s)

Eo:

Eötvös number

Ga:

Galo number

Nu:

Nusselt number

Pr:

Prandtl number for gas

Re:

Reynolds number for the gas phase

Sc:

Schmidt number

Sh:

Sherwood number

References

  1. Slin’ko, M.G., Kirillov, V.A., Kuzin, N.A., and Shigarov, A.B., Nonlinear Phenomena in a Downward Gas-Liquid Flow through a Fixed Granular Catalyst Bed, Dokl. Akad. Nauk, 2001, vol. 380, no. 1, pp. 77–81 [Dokl. Chem. (Engl. Transl.), vol. 380, nos. 1–3, pp. 271–275].

    CAS  Google Scholar 

  2. Shigarov, A.B., Kuzin, N.A., and Kirillov, V.A., Phase Disequilibrium in the Course of an Exothermic Reaction Accompanied by Liquid Evaporation in a Catalytic Trickle-Bed Reactor, Teor. Osn. Khim. Tekhnol., 2002, vol. 36, no. 2, pp. 181–188 [Theor. Found. Chem. Eng. (Engl. Transl.), vol. 36, no. 2, pp. 159–165].

    Google Scholar 

  3. Cheng, Z.-M., Anter, A.M., and Yuan, W.-K., Intensification of Phase Transition on Multiphase Reactions, AIChE J., 2001, vol. 47, pp. 1185–1192.

    Article  CAS  Google Scholar 

  4. Cheng, Z.-M., Anter, A.M., Fang, X.-C., Xiao, Q., Yuan, W.-K., and Bhatia, S.K., Dryout Phenomena in a Three-Phase Fixed-Bed Reactor, AIChE J., 2003, vol. 49, pp. 225–231.

    Article  CAS  Google Scholar 

  5. McManus, R.L., Funk, G.A., Harold, M.P., and Ng, K.M., Experimental Study of Reaction in Trickle-Bed Reactors with Liquid Maldistribution, Ind. Eng. Chem. Res., 1993, vol. 32, pp. 570–574.

    Article  CAS  Google Scholar 

  6. Hanika, J., Lukjanov, B.N., Kirillov, V.A., and Stanek, V., Hydrogenation of 1,5-Cyclooctadiene in a Trickle-Bed Reactor Accompanied by Phase Transition, Chem. Eng. Commun., 1986, vol. 40, pp. 183–194.

    CAS  Google Scholar 

  7. Kheshgi, H.S., Reyes, S.C., Hu, R., and Ho, T.C., Phase Transition and Steady-State Multiplicity in a Trickle-Bed Reactor, Chem. Eng. Sci., 1992, vol. 47, pp. 1771–1777.

    Article  CAS  Google Scholar 

  8. Hanika, J., Sporka, K., Ruzicka, V., and Krausova, J., Qualitative Observations of Heat and Mass Effects on the Behavior of a Trickle-Bed Reactor, Chem. Eng. Commun., 1975, vol. 2, pp. 19–25.

    CAS  Google Scholar 

  9. Hanika, J., Sporka, K., Ruzicka, V., and Hrstka, J., Measurement of Axial Temperature Profiles in an Adiabatic Trickle-Bed Reactor, Chem. Eng. J., 1976, vol. 12, pp. 193–197.

    Article  CAS  Google Scholar 

  10. Khadilkar, M.R., Mills, P.L., and Dudukovic, M.P., Trickle-Bed Reactor Models for Systems with a Volatile Liquid Phase, Chem. Eng. Sci., 1999, vol. 54, pp. 2421–2431.

    Article  CAS  Google Scholar 

  11. Kirillov, V.A., Kuzin, N.A., Kulikov, A.V., Luk’yanov, B.N., Khanaev, V.M., and Shigarov, A.B., Teor. Osn. Khim. Tekhnol., 2000, vol. 34, no. 5, pp. 526–536 [Theor. Found. Chem. Eng. (Engl. Transl.), vol. 34, no. 5, pp. 475–484].

    Google Scholar 

  12. Aerov, M.E. and Todes, O.M., Gidravlicheskie i teplovye osnovy raboty apparatov so statsionarnym i kipyashchim zernistym sloem (Hydraulic and Thermal Principles of Operation of Apparatuses with Fixed and Fluidized Granular Beds), Moscow: Khimiya, 1968.

    Google Scholar 

  13. Reid, R.C., Prausnitz, J.M., and Sherwood, T.K., The Properties of Gases and Liquids, New York: McGraw-Hill, 1977. Translated under the title Svoistva gazov i zhidkostei, Leningrad: Khimiya, 1982.

    Google Scholar 

  14. Krishna, R. and Wesselingh, J.A., The Maxwell-Stefan Approach to Mass Transfer, Chem. Eng. Sci., 1997, vol. 52, pp. 861–911.

    Article  CAS  Google Scholar 

  15. Al-Dahhan, M.N. and Dudukovic, M.P., Catalyst Wetting Efficiency in Trickle-Bed Reactors at High Pressure, Chem. Eng. Sci., 1995, vol. 50, pp. 2377–2389.

    Article  CAS  Google Scholar 

  16. Specchia, V. and Baldi, G., Pressure Drop and Liquid Holdup for Two-Phase Cocurrent Flow in Packed Beds, Chem. Eng. Sci., 1977, vol. 32, pp. 515–523.

    Article  CAS  Google Scholar 

  17. Saez, A.E., Yepez, M.M., Cabrera, C., and Soria, E.M., Static Liquid Holdup in Packed Beds of Spherical Particles, AIChE J., 1991, vol. 37, pp. 1733–1736.

    Article  CAS  Google Scholar 

  18. Prchlik, J., Soukup, J., Zapletal, V., and Ruzicka, V., Liquid Distribution in Reactors with Randomly Packed Porous Beds, Collect. Czech. Chem. Commun., 1975, vol. 40, no. 3, pp. 845–855.

    CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, pr. Akademika Lavrent’eva 5, Novosibirsk, 630090, Russia

    V. V. Kireenkov, A. B. Shigarov, N. A. Kuzin, A. A. Bocharov & V. A. Kirillov

Authors
  1. V. V. Kireenkov
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. B. Shigarov
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. N. A. Kuzin
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. A. A. Bocharov
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. V. A. Kirillov
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

Original Russian Text © V.V. Kireenkov, A.B. Shigarov, N.A. Kuzin, A.A. Bocharov, V.A. Kirillov, 2006, published in Teoreticheskie Osnovy Khimicheskoi Tekhnologii, 2006, Vol. 40, No. 5, pp. 508–519.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kireenkov, V.V., Shigarov, A.B., Kuzin, N.A. et al. Effect of the nonuniformity of the inlet liquid distribution on the trickle-bed reactor output in an exothermic reaction accompanied by evaporation. Theor Found Chem Eng 40, 472–482 (2006). https://doi.org/10.1134/S0040579506050046

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1134/S0040579506050046

Keywords

Search

Navigation