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Library of Congress Cataloging-in-Publication Data
Names:Ancheyta Juárez, Jorge, author.
Title: Deactivation of heavy oil hydroprocessing catalysts : fundamentals and modeling / Jorge Ancheyta.
Description: Hoboken, New Jersey : John Wiley & Sons, 2016. | Includes bibliographical references and index.
Identifiers: LCCN 2016019443| ISBN 9781118769843 (cloth) | ISBN 9781118769812 (epub)
Subjects: LCSH: Petroleum--Refining. | Catalyst poisoning.
Classification: LCC TP690.8 .A53 2016 | DDC 622/.33827--dc23 LC record available at https://lccn.loc.gov/2016019443
Cover image courtesy of GettyImages/avdeev007
Jorge Ancheyta, PhD, graduated with a Bachelor's degree in Petrochemical Engineering (1989), Master's degree in Chemical Engineering (1993), and Master's degree in Administration, Planning, and Economics of Hydrocarbons (1997) from the National Polytechnic Institute (IPN) of Mexico. He splits his PhD between the Metropolitan Autonomous University (UAM) of Mexico and the Imperial College London, UK (1998), and was awarded a postdoctoral fellowship in the Laboratory of Catalytic Process Engineering of the CPE-CNRS in Lyon, France (1999). He has also been a visiting professor at the Laboratoire de Catalyse et Spectrochimie (LCS), Université de Caen, France (2008, 2009, 2010), Imperial College London, UK (2009), and Mining University at Saint Petersburg, Russia (2016).
He has worked for the Mexican Institute of Petroleum (IMP) since 1989 and his present position is Manager of Products for the Transformation of Crude Oil. He has also worked as professor at the undergraduate and postgrade levels for the School of Chemical Engineering and Extractive Industries at the National Polytechnic Institute of Mexico (ESIQIE-IPN) since 1992 and for the IMP postgraduate since 2003. He has been supervisor of more than one hundred BSc, MSc, and PhD theses. He has also been supervisor of a number of postdoctoral and sabbatical year professors.
He has been working in the development and application of petroleum refining catalysts, kinetic and reactor models, and process technologies mainly in catalytic cracking, catalytic reforming, middle distillate hydrotreating, and heavy oils upgrading. He is author and coauthor of a number of patents, books, and about 200 scientific papers, and has been awarded the highest distinction (Level III) as National Researcher by the Mexican government and is a member of the Mexican Academy of Science. He has also been guest editor of various international journals, for example, Catalysis Today, Petroleum Science and Technology, Industrial Engineering Chemistry Research, Chemical Engineering Communications, and Fuel. He has also chaired numerous international conferences.
Apart from the reactor, catalyst is another important component of a chemical process, and a thorough understanding of the catalytic phenomena occurring during the transformation of reactants into desired products is of vital importance for the development and optimization of the process.
In the case of petroleum refining industry, it is currently immersed in the dilemma of higher production of heavy petroleum compared with that of light petroleum. Producing and refining heavy crude oils is more complicated since they exhibit higher content of impurities (sulfur, nitrogen, metals, and asphaltenes), as well as higher yield of residue with consequent low production of valuable distillates (gasoline and diesel) than conventional crude oils, which in turn are responsible for the low price of heavy petroleum. And not only that, the existing refineries have been designed to process light crude oil and heavy crude oil can only be blended at a certain reduced proportion. To increase the diet of heavy crude oils as feed to a refinery, units require major changes or installation of new plants.
A solution to this problem is the use of heavy crude oil upgrading processes prior to a refinery or conversion processes for the upgrading of bottom-of-barrel (heavy residue) in the refinery. These upgrading processes are able to convert heavy oil into medium/light oil with reduced amounts of impurities and high content of valuable distillates, by two main principles: carbon rejection and hydrogen addition. In the latter case, catalytic hydrotreating is the most used technology in commercial application.
For a proper design of heavy petroleum hydroprocessing reactors, it is required to have simulation tools based on information collected in laboratory experiments, which consist of mathematical models to represent the phenomena occurring during heavy oil conversion. The hydroprocessing reactors are complex and complicated to model and design. The composition and properties of heavy petroleum that is converted in reactors are such that the reaction system can involve various phases, different types of catalysts, reactor configuration, reaction conditions, catalyst deactivation, and so on, making the development of a model a challenging task. Moreover, hundreds of components are present in heavy petroleum that undergo different reaction pathways and compete for the active sites of catalysts, which contribute to increasing the complexity for the formulation of the kinetics, catalyst deactivation, and reactor models.
Deactivation of hydroprocessing catalyst is mainly due to the formation of carbonaceous (coke) and metal depositions, which block the pore mouth leaving unutilized catalytic active sites. This is the most important concern during hydroprocessing of heavy oils, since the life of the catalyst and the entire economy of the process strongly depend on it. Hence, from the industrial point of view, modeling the catalyst deactivation is highly valuable. The deactivation phenomenon is commonly divided into three stages: early deactivation due to coke deposition, middle stage deactivation due to loss of sites by poisoning and pore plugging by metal-sulfide deposits, and total loss of activity by severe diffusional resistances due to almost total pore plugging.
Modeling the kinetics and catalyst deactivation is of great importance for proper reactor and process design as well as to establish suitable operating policies to compensate for the loss of catalyst activity during time-on-stream.
Deactivation of Heavy Oil Hydroprocessing Catalysts: Fundamentals and Modeling deals with this topic of current and future relevance: the loss of activity of catalyst during hydroprocessing of heavy oils. The book is organized in five chapters, each one having individual references. More than 400 references are cited and discussed within the entire book, which cover practically all the previous published literature regarding the fundamentals and modeling of catalyst deactivation during hydroprocessing.
Chapter 1 is dedicated to introduce those readers requiring an in-depth knowledge on topics related to the properties of heavy oils, such as petroleum refining processes, asphaltenes, tendency to coke formation, viscosity of crude oils and blends, stability, compatibility, and assay of petroleum. A brief description of all the petroleum refining processes is given. Detailed experimental data of light, medium, and heavy crude oil are also provided.
Chapter 2 deals with the properties of catalysts for heavy oil hydroprocessing. Particular mention is done to the description of the preparation, characterization, and evaluation of hydroprocessing catalysts using heavy oils. Some of the most important features that must be taken into account when processing heavy feeds are also discussed.
Chapter 3 is devoted to the description and analysis of the deactivation of hydroprocessing catalysts. Detailed descriptions are provided on the reactors used for hydroprocessing of heavy oils, process variables, effect of reaction conditions on catalyst deactivation, mechanisms of catalyst deactivation, and the effect of asphaltenes on it.
Chapter 4 aims at describing the characterization of spent hydroprocessing catalysts. The main characterization techniques are commented. A series of several studies on heavy oil hydroprocessing are reported in detail, which include synthesis of supports and catalysts, and evaluation of hydroprocessing catalyst and its deactivation at different reaction experimental scales.
Chapter 5 is focused on the modeling of catalyst deactivation. Various approaches are described and discussed in detail using different study cases, such as the effect of reactor configuration on the cycle length of heavy oil fixed-bed hydroprocessing, effect of different heavy feedstocks on catalyst deactivation, modeling deactivation by metal deposition, modeling short-term catalyst deactivation, modeling parallel thermal and catalytic hydrotreating including deactivation, modeling catalyst deactivation by the continuous kinetic lumping model, and application of a three-stage approach for modeling the complete period of catalyst deactivation during hydroprocessing of heavy oils. The kinetic modeling approaches, estimation of model parameters, and reactor model and catalyst deactivation models are described.
The development of correlations and models is thoroughly described with the aid of detailed experimental data collected from different reaction scales. Experimental data, explanations of how to determine model parameters, and rigorous treatment of the different topics as well as the step-by-step description of the models formulation and application will make this book an indispensable reference not only for professionals working in the area of modeling reactor and catalyst deactivation but also a textbook for full courses in chemical reaction engineering.
It is anticipated that Deactivation of Heavy Oil Hydroprocessing Catalysts: Fundamentals and Modeling becomes promptly an outstanding and distinctive book because it emphasizes a detailed description of fundamentals and modeling of catalyst deactivation, uses laboratory and commercial data for model validations, gives details of results of simulations at different conditions, and, in general, focuses on more practical issues regarding modeling of catalyst deactivation than textbooks published related to the topic in the past.
Jorge Ancheyta
Mexico city, Mexico.
2016
a0, a1, S0 | parameters of yield distribution function Equation (5.58) |
A1, B1 | Riazi's correlation parameters |
A2 | Goto and Smith's correlation parameter |
A | fitting parameter of Equation (5.13) |
Arrhenius preexponential factor for catalytic kinetic constants (h−1) | |
Arrhenius preexponential factor for deactivation constants (h−1) | |
van't Hoff preexponential factor for hydrogen sulfide adsorption constant (cm3/mol) | |
aL | gas–liquid interfacial area (cm−1) |
aMOC | unit conversion factor of Equation (5.17) |
AS | sectional area of the reactor (cm−2) |
aS | liquid–solid interfacial area (cm−1) |
Arrhenius preexponential factor for thermal kinetic constants (h−1) | |
B | matrix for orthogonal collocation, fitting parameter of Equation (5.13) |
C | reactant or species concentration |
CA | reactant concentration of A species |
asphaltene content (wt%) | |
reactant concentration at entrance of reactor system | |
basic nitrogen content (ppm) | |
hydrogen concentration (mol/cm3) | |
Ci | molar concentration of compound i (cm3/mol), content of the compound i at the reactor outlet |
content of the compound i at the reactor inlet | |
c(k,τ) | concentration of the species with reactivity k at residence time τ |
c(k, 0) | concentration of the species with reactivity k in the feed |
hydrogen sulfide concentration (mol/cm3) | |
nonbasic nitrogen content (ppm) | |
nickel content (ppm) | |
Cp | molar concentration of compound i (cm3/mol) |
sulfur content (wt%) | |
vanadium content (ppm) | |
cwt | cumulative weight fraction |
D | bulk diffusion |
effective diffusivity of A in the pores of catalyst | |
D(k) | species-type distribution function for hydrocracking reaction |
Dr | restrictive diffusion coefficient |
dp | catalyst particle diameter |
dt | reactor diameter |
D0 | initial diffusion coefficient within pore catalyst |
Dt | diffusion coefficient within pore catalyst |
activation energy for the catalytic reactions (kcal/mol) | |
activation energy for the thermal reactions (kcal/mol) | |
deactivation energy for the reaction i (kcal/mol) | |
EOR | end-of-run |
e | exponential function basis |
g | gas mass rate (g/s) |
GL | superficial liquid mass velocity (kg/m2 s) |
Hi | Henry's law constant for compound i (MPa cm3/mol) |
H2/oil | hydrogen-to-oil ratio (std m3/m3) |
I | degree of polynomial |
I0 | Bessel function of the first kind, zero order |
I1 | Bessel function of the first kind, first order |
K | reaction rate constant per unit of surface area |
k | hydrocracking reactivity of any species (h−1) |
k0 | global rate constant for hydrocracking of residue |
k1 | second-order rate constant for hydrocracking of residue to VGO |
k2 | second-order rate constant for hydrocracking of residue to distillates |
k3 | second-order rate constant for hydrocracking of residue to naphtha |
k4 | second-order rate constant for hydrocracking of residue to gas |
k5 | first-order rate constant for hydrocracking of VGO to distillates |
k6 | first-order rate constant for hydrocracking of VGO to naphtha |
k7 | first-order rate constant for hydrocracking of VGO to gases |
k8 | first-order rate constant for hydrocracking of distillates to naphtha |
k9 | first-order rate constant for hydrocracking of distillates to gases |
k10 | first-order rate constant for hydrocracking of naphtha to gases |
kapp | apparent rate coefficient |
kinetic constants for the three and four kinetic models | |
catalytic kinetic constant for the HDAsph reaction (wt%−0.503/h) | |
catalytic kinetic constant for the HDNBN reaction (ppm−0.792/h) | |
catalytic kinetic constant for the reaction i | |
catalytic kinetic constant for the HDNNBN reaction (wt%−1.154/h) | |
catalytic kinetic constant for the HDNi reaction (ppm−1.406/h) | |
catalytic kinetic constant for the HDS reaction (wt%−0.503/h) | |
catalytic kinetic constant for the HDV reaction (ppm0.290/h) | |
kd | deactivation rate constant |
deactivation constant for the reaction i (h−1) | |
adsorption-equilibrium constant for the hydrogen sulfide (cm3/mol) | |
kint | reaction rate constant |
gas–liquid mass transfer coefficient for compound i (cm/s) | |
liquid–solid mass transfer coefficient for compound i (cm/s) | |
ki | intrinsic rate coefficient |
kmax | hydrocracking reactivity of the species with the highest TBP in the mixture (h−1) |
kp | particle rate coefficient |
thermal kinetic constant for the HDAsph reaction (wt%0.795/h) | |
thermal kinetic constant for the HDNBN reaction (ppm0.137/h) | |
thermal kinetic constant for the reaction i | |
thermal kinetic constant for the HDNNBN reaction (ppm0.137/h) | |
thermal kinetic constant for the HDNi reaction (ppm0.350/h) | |
thermal kinetic constant for the HDV reaction (ppm0.487/h) | |
thermal kinetic constant for the HDS reaction (wt%0.062/h) | |
L | characteristic catalyst particle size |
LHSV, l | liquid hourly space velocity (h−1) |
Mms | molecular weight of metal sulfide compounds |
MOC | concentration of metals-on-catalyst (wt%) |
MOR | middle-of-run |
m | deactivation rate order |
mi | deactivation order for the reaction i |
total mass flow | |
N | reaction order, total number of species in the mixture, total concentration of sites available for any particular reaction |
n | reaction order of the hydrocracking of residue |
reaction order of the catalytic reaction rate i | |
nj | order of reaction j |
reaction order of the thermal reaction rate i | |
NA | molar flow across circle area |
Ni | concentration of any active sites at any time-on-stream, molar flow of compound i (mol/s) |
concentration of any active sites at initial time-on-stream | |
N1 | concentration of sites type I |
N2 | concentration of sites type II |
P | total pressure (MPa) |
pi | partial pressure of compound i (MPa) |
q | quench fluid mass flow rate (g/s) |
R1 | first reactor |
R2 | second reactor |
R | universal gas constant (kcal/mol K) |
reaction rate of distillates | |
reaction rate of gases | |
HDCCR reaction rate (wt%/h) | |
HDAsph reaction rate (wt%/h) | |
HDNB reaction rate (ppm/h) | |
HDNNBN reaction rate (ppm%/h) | |
HDNi reaction rate (ppm/h) | |
HDS reaction rate (wt%/h) | |
HDV reaction rate (ppm/h) | |
rj | rate of jth reaction (mol/cm3 s) |
rmol | molecular radius of metal-bearing compounds |
rN | reaction rate of naphtha |
rp | instantaneous pore radius |
rR | reaction rate of residue |
rVGO | reaction rate of VGO |
S | cross-flow area |
SOR | start-of-run |
Sp | total geometric external area of particle |
t | time |
t | time-on-stream (h) |
T | absolute temperature |
T0 | boiling temperature of the lightest compound in the feed mixture |
TBP | true boiling point of any pseudocomponent (K) |
TBP(h) | highest boiling point of any pseudocomponent in the mixture (K) |
TBP(l) | lowest boiling point of any pseudocomponent in the mixture (K) |
Tmean | mean absolute temperature |
TOS | time-on-stream |
t∞ | catalyst life |
uG | gas superficial velocity (cm/s) |
uL | liquid superficial velocity (cm/s) |
Vp | total geometric volume of catalyst |
v | molar liquid volume |
x | hydrocracking reactivity of any species (h−1); variable of integration |
xMOC | fraction concentration of metals-on-catalyst (MOC) |
yD | distillates composition |
yG | gas composition |
yN | naphtha composition |
yR | residue composition |
yVGO | VGO composition |
Wcat | weight of catalyst (g) |
WHSV | weight hourly space velocity (h−1) |
wt | weight fraction of species |
wt1,2(τ) | concentration in weight fraction of any pesudocomponent with arbitrary boiling point range as function of residence time |
z | position within pore, Axial coordinate along the reactor |
Subscripts | |
0 | initial |
f | feed |
Asph | asphaltenes |
BN | basic nitrogen |
CCR | Conradson carbon residue |
HDS | hydrodesulfurization |
HDNi | hydrodenickelation |
HDV | hydrodevanadization |
HDAsph | hydrodeasphaltenization |
HDCCR | hydro-Conradson carbon residue conversion |
HDM | hydrodemetalization |
HDNNBN | hydrodenitrogenation of nonbasic nitrogen |
HDNBN | hydrodenitrogenation of basic nitrogen |
i | S, Ni, V, Asph, CCR, NBN, BN |
in | intrinsic |
in | inlet to the following catalytic bed |
NBN | nonbasic nitrogen |
Ni | nickel |
out | outlet of the previous catalytic bed |
p | product |
q | quench stream |
r | restrictive |
S | sulfur |
t | instantaneous |
V | vanadium |
Greek Symbols | |
α | geometry parameter, model parameter in Equation (5.62), fitting parameter of Equations (5.16) and (5.58) |
α1 | rate constant of diminution on sites concentration type I |
α2 | rate constant of diminution on sites concentration type II |
β | proportional constant in Equation (5.101), fitting parameter of Equations (5.16) and (5.58) |
Γ | gamma function |
γ | ratio of instantaneous pore radius to initial pore radius |
γ | fitting parameter of Equations (5.16) and (5.58) |
ΔHads | enthalpy of adsorption of hydrogen sulfide (kcal/mol) |
ΔHR | overall heat of reaction (kJ/kg sulfur) |
δ | metal sulfide thickness within catalyst pore, model parameter of hydrocracking yield distribution function (p(k, K)) |
є | metal sulfide molecules per molecule of reactant |
ɛ0 | bed void fraction |
ɛL | dynamic liquid holdup |
ζ | dimensionless intraparticle position |
η | effectiveness factor |
η0 | initial effectiveness factor |
ηt | effectiveness factor affected by diffusional resistances |
ηEF | effectiveness factor |
ηCE | solid–liquid contact efficiency factor, external catalyst wetting efficiency |
ϕ , φ |
catalyst activity |
ϕA | deactivation function of active sites |
ϕD | deactivation function due to deposits |
φj | deactivation function of jth reaction |
φCoke | deactivation function for coking reactions |
φMetals | deactivation function for metals deposition |
θ | deactivation function for metals deposition |
λ | ratio of molecule radius to pore radius |
μ | dynamic liquid viscosity |
ρG | gas density at process conditions (g/cm3) |
ρms | metal sulfide compound density |
ρL | liquid density at process conditions (g/cm3) |
ρoil | heavy oil density |
τ | dimensionless time |
τ | inverse of space velocity or residence time (h) |
φ | thiele modulus |
χ | dimensionless reactant concentration |
Superscripts | |
app | apparent |
G | gas phase |
L | liquid phase |
Q | quench fluid |
S | solid phase |