UETHOf) FOR - ACTIVATING ~.BYMROTWEA'I'IINC~A TWLYE
FIELD OF THE INVENTION
5 [OOOll The present invention relates to hydrotreating reactions. Notably it relates to the
hydrotreating reactions employed during the hydrocracking of petroleum cuts and during
the transformation of biomass. The present invention therefore relates both to the field of
petroleum refining and to the field of the production of biofuels, in which activation of
hydrotreating catalysts is carried out. More particularly, it relates to the activation of
l o catalysts employed during these hydrotreating operations, designated below as
"hydt.otreating catalyst(s)". Even more specifically, the inventiori relates to a method for insitu
activation of hydrotreating catalysts and to the use of specific nitrogen compounds
during said method for controlling the activity of the hydrotreating catalysts.
15 TECHNOLOGICAL BACKGROUND
[BOO21 Hydrotreating is a process that makes it possible, by treatment with hydrogen,
notably to reduce the quantity of compounds such as sulphide compounds, nitrogen
compounds, oxygenated compounds or of metals, present in a product or a mixture of
products. This hydrotreating process is used in numerous fields and particularly in the field
20 of petroleum refining for purifying petroleum cuts, but also in the field of the production of
biofuels.
[0003] Among the biofuels, a distinction is made between those said to be of first
generation, for example ethanol obtained from the fermentation of sugar plants (sugar
beet, sugar cane, etc.) or from enzymatic hydrolysis of the starch of cereals (maize,
25 wheat, etc.), and the biodiesel obtained by transesteriication of vegetable oils using
methanol. Generally, these processes that are familiar to a person skilled in the art do not
use hydrogen and do not employ hydrotreating processes.
[0004] The development of these first-generation biofuels has created controversy
notably because of their origins. In fact, the raw materials required for these biofuels
30 involve intensive crop growing which will compete with agricultural production for food
purposes. To overcome this problem, considerable research effort has been deployed for
developing second-generation biofuels, in order to utilize other natural raw materials such
as non-food vegetable oils, waste vegetable or animal oils, such as used frying oil, animal
fats, and others.
35 [0005] Among these second-generation biofuels, some are obtained from lignocellulosic
biomass such as wood, straw, agricultural waste, forestry residues or else dedicated
species such as Miscanthus (eiephant grass), or switcihgrass. This lignocellulosic biomass
is transformed by pyrolysis at high temperature, for example between 400°C and 700°C.
At this temperature, the constituent elements ofthe biomass such as cellulose, lignin and
hemicellulose will depolymerize, and break up into lighter molecules, which will evaporate.
5 On cooling, the vzpours condense to form a liquid product called pyrolysis oil, which is
mainly composed of water, phenols, ketones, aldehydes, alcohols, carboxylic acids, and
carbohydrates.
[0006] The use of pyrolysis oil or other compounds of natural origin comprising aiiphatic
chains as precursors of biofuels most often requires transformations and purifications. in
10 fact, ali these natural compounds have high concentrations of impurities, for example the
oxygenated compounds and structures incompatible with direct use as fuel. Moreover,
pyrolysis oil is chemically unstable and this instability increases with the temperature,
which is a real problem for a fuel.
[0007] These compounds of natural origin such as pyrolysis oil are thus improved using
15 additional processes disclosed in the prior art, and more particularly hydrotreating
processes.
[0008] Hydrotreating is not restricted to the field of biofuels, this process is also used in
numerous other fields, and quite particularly in the refinery field, and more particularly
during the transformation (so-called "cracking") of heavy cuts into light fractions. In fact,
20 during petroleum refining, cracking is an operation that consists of transforming complex
organic molecules into compounds of lower molecular weights. Various techniques may
be employed, which include in particular catalytic cracking and hydrocracking.
[0009] Catalytic cracking is an endothermic reaction mainly for producing fuels (such as
gasolines and gas oil) and light olefins (for example propylene, butylene, and others). This
25 process consists essentially of cracking hydrocarbons at high temperature, for example
from 450°C to 550°C, at a pressure close to atmospheric pressure, for example from 1 to
5 bar (i.e. from l.105 Pa to 5.105 Pa), and is accompanied by formation of carbon, which is
deposited on the catalyst. The latter Is in motion in the fluidized-bed unit so as to be
regenerated continuously by combustion of the carbon by the air.
30 [OOIO] Hydrocracking mainly allows gas oil, kerosene and gasoline to be obtained. This
process consists essentially of cracking hydrocarbons at lower temperature, for example
from 250°C to 450% under high hydrogen pressure, for example from 50 to 200 bar (or
from 50.105 to 200.105 Pa).' This reaction is accompanied by other reactions of
hydrogenation of unsaturated compounds andior of impurities, such as sulphide and
35 nitrogen for example. These hydrogenated impurities can easily be separated from the
hydrocarbon cuts, which then meet the specifications for commercial fueis. In particular,
hydrocracking is carcried out in the presence of a catalyst, in a fixed bed, which
necessitates stopping the process periodically to reactivate the catalyst by sulphiding of
the latter.
[DO411 The present invention thus relates to hydrocracking, and not to catalytic cracking.
5 /[DO123 The term "hydrotreating", as used in the present descriptioc, describes a catalytic
process of hydrogenation of a feed under pressure in order to produce fuels, especially
purified fuels. This term comprises both the term "hydrocracking", which involves both the
usual reactions aiming, with hydrogen, to break bonds between heteroatoms (mainly
oxygen, nitrogen and sulphide) and carbon atoms, and reactions of cracking and
10 isomerization of carbon-carbon bonds in order to reduce the chain length and obtain a
more branched skeleton.
[0013] These two processes employ common catalysts. Thus, hereinafter, the term
hydrotreating notably comprises the terms hydrogenation, hydroisomerization,
hydrodenitrogenation, hydrodesulfurization, hydrodeoxygenation, dearomatization,
15 hydroconversion, in particular hydrocracking and more particularly all reactions that
involve hydrogen.
I00141 During the operation of activation or reactivation of the hydrotreating catalyst,
especially hydrocracking catalyst, if nothing is done to inhibit the cracking reaction,
reaction runaway may develop owing to the strongly exothermic nature of this reaction.
20 This may result in loss of activity and deterioration of the catalyst, or even damage to
industrial equipment. This phenomenon may also occur during the production of biofuels,
more particularly of biofuels obtained from lignocellulosic biomass.
[00'i5] A known way of avoiding this problem is to use a nitrogen compound, generally
ammonia or aniline, aniline then being used as an ammonia precursor. In fact, ammonia,
25 introduced or generaied in situ, passivates the catalyst by reacting with its acid sites that
are responsible for its activity of hydrotreating, in particular of hydrocracking, called
hydrotreating activity or hydrocracking activity, respectively. Once these acid sites have
thus been deactivated, the reaction of hydrotreating, in particular of hydrocracking is
inhibited and sulphiding of the catalyst may take place in complete safety.
30 [00f6] Sulphiding consists of bringing a sulphiding agent, for example hydrogen
sulphide or a precursor of hydrogen sulphide, Into contact with the hydrotreating, in
particular hydrocracking, catalyst. When sulphiding is carried out under hydrogen at high
temperature, this results in complete transformation of the metals present in the catalyst to
metal sulphides. The hydrotreating, in particular hydrocracking, catalyst is then activated.
35 [0011] Activation of hydrotreating, in particular hydrocracking, catalysts is carried out
either ex situ, outside the hydrotreating, in particular hydrocracking, reactor, or in situ,
inside the hydrotreating, in particular hydrocraclting, reactor. These tvrio methods are
known by a person skilled in the aii.
[00281 During the ex-situ process, carried out in a moving bed, a sulphiding agent is
brought into contact with the catalyst. The catalyst is optionally treated thermally in the
5 absence or in the presence of hydrogen at a pressure equal to or close to atmospheric
pressure. Thus, the catalyst is presulphurized or presulphurized and activated,
respectively.
[0019] Moreover, to control the hydrotreating, in particular hydrocracking, activity, of the
hydrotreating, in particular hydrocracking, catalyst respectively, a nitrogen compound is
10 generally brought into contact, ex situ, with the hydrotreating, in paiiicular hydrocracking,
catalyst, respectively. The catalyst obtained is generally dried ex situ. Generally, the
hydrotreating, in particular hydrocracking, catalyst is not ready to be used as it is, and it
may be desirable, or even necessary, to passivate the catalyst, most offen in situ, under
high hydrogen pressure and at high temperature.
15 [0020] During this in-situ process, usually carried out in a fixed bed, a sulphiding agent is
introduced into the hydrotreating, in particular hydrocracking, reactor under high hydrogen
pressure and at high temperature. This sulphiding step then allows the catalyst to be
activated.
[002$] Moreover, a nitrogen compound is introduced into the hydrotreating, in particular
20 hydrocracking, reactor under high hydrogen pressure and at high temperature, thus
allowing passivation of the acid sites of the hydrotreating, in particular hydrocracking,
catalyst.
[0022] Such processes are familiar to a person skilled in the art and are widely
described in the scietitific literature and in patents. Thus, international application WO
25 2014/001633 describes a process for hydroconversion of wood byproducts to biofuels that
comprises a hydrotreating step and an isomerization step. This last-mentioned step uses
metal catalysts supported on molecuiar sieves or zeolites.
[0023] Document US200910308790 describes a hydrogenation catalyst and a method
for preparing this catalyst ex situ in the presence of an organonitrogen compound, a
30 sulphiding agent and an organic solvent. The organonitrogen compounds of document
US200910308790 preferably comprise nitrogen and oxygen simultaneously.
[0024] Patent application FR2778349 describes a method for activating hydroconversion
catalysts, using at least one sul'phide compound and at least one nitrogen compound.
[0025] Document FR2668951 describes hwo methods for activation of hydrocracking
3 catalysts, one in situ and the other ex situ, comprising a step of passivation of the acid
sites of the catalysts. According to this document, this step may be carried out in the
presence of a nitrogen compound selected from primary, secondary or tertiary arnines,
compounds containing a quaternary ammonium, arylamines such as the compounds of
the aniline family, pyrroles and homologues thereof, pyridines, nitriles, ureas and
thio-ureas, nitrated, nitrous or nitroso derivatives, or any other basic compound or
5 compound that can be converted into s basic compound, notably ammonia, under
hydrogen pressure, at high temperature and in the presence of a catalyst.
[O026] These nitrogen compounds do not, however, offer a good compromise in terms of
controlling the risk of operator exposure, and constraints relating to manipulation and
storage, odor and effectiveness of inhibition of the catalyst while not adversely affecting
3.0 the catalyst activity. For example, ammonia is malodorous and it requires meticulous
handling; and aniline is now regarded as CMR (carcinogenic, mutagenic, reprotoxic)
according to the European CLP ("Classification, Labelling, Packaging") regulations.
[0027] Moreover, the method for activating hydrotreating, in particular hydrocracking,
catalysts, especially when it is carried out ex situ, presents the following disadvantages:
15 - passivation of the catalyst under high hydrogen pressure requires an additional step in
the hydrotreating, in particular hydrocracking, method, since it is generally carried out in
situ before hydrotreating, in particular before hydrocracking;
- the nitrogen compound and the sulphiding agent may be desorbed from the
hydrotreating, in particular hydrocracking, catalyst, before the latter is fed into the
20 hydrotreating, in particular hydrocracking, reactor;
- an additional drying step Is generally necessary, increasing the duration of the ex situ
method;
-the activity of the hydrotreating, and in particular hydrocracking, catalysts is more difficult
to control because passivation is not generally carried out ex situ.
25 [0028] Thus, there is still a need for an improved method for in-situ activation of
hydrotreating catalysts, and in particular of hydrocracking catalysts. In fact, during
sulphiding of the catalysts, the reactions of cracking or of isomerization are troublesome.
These reactions are very exothermic and may adversely affect the final activity of the
catalyst, or even make the activation operation uncontrollable. There is in particular a
30 need for a compound or a mixture of compounds making it possible, during activation of
hydrotreating and in particular hydrocracking catalyst(s), to inhibit the activity of the
catalyst temporarily but without adversely affecting its effectiveness when it is employed in
hydrotreating, and in particular in hydrocracking, and which offers a good compromise in
terms of controlling the risks of operator exposure, and constraints relating to handling,
3 5 storage andlor odor.
DESCRIPTION OF rtiE I N V E N . ~
lo0291 This technical probiern is soived, completely or at ieast partially, by the present
invention. Yet other advantages will become clear from the description of the invention
given hereunder.
5 100301 The present invention relates to the use, in a method for in-situ activation of at
least one hydrotreating, in particular hydrocracking, catalyst, of at least one nitrogen
compound having at least one, preferably at least two, more preferably at least three,
even more preferably at least four of the foliowing characteristics:
a) a nitrogen content by weight in the range from 15 to 35 wt%, preterably in the range
10 from 20 to 35%, more preferably in the range from 20 to 30%, and more advantageously
in the range from 20 to 25% relative to the total weight of the nitrogen compound;
b) a number of nitrogen atoms in the range from 2 to 20, preferably in the range from 2 to
15, more preferably in the range from 2 to 10, even more preferably in the range from 2 to
5, per molecule, advantageously two nitrogen atoms per motecuie;
15 c) a boiling point in the range from 140°C to 300°C, preferabiy in the range from 140°C to
250°C, more preferabiy in the range from 140°C to 200°C, even more preferably in the
range from 140°C to 175°C; and
d) said nitrogen compound being in liquid form at room temperature and atmospheric
pressure.
20 [0031] The invention also relates lo the use of at least one nitrogen compound as
defined above for controlling the activity of at least one hydrotreating catalyst, in particular
of at least one hydrocracking catalyst.
[0032] The invention also relates to the use of at ieast one nitrogen compound as
defined above for passivating the acid sites of the hydrotreating catalyst, in particular of
25 the hydrocracking catalyst.
100331 The invention finally relates to a method for in-situ activation of at least one
hydrotreating cataiyst, in particular one hydrocracking catalyst, said method comprising at
least:
1) a step of sulphiding said hydrotreating, in particular hydrocracking, catalyst, in the
3 0 presence of a sulphiding agent; and
2) a step of passivation of said hydrotreating, in particular hydrocracking, catalyst, in the
presence of at least one nitrogen compound as defined in the present invention.
fOQ341 The present invention makes it possible to overcome the drawbacks of the prior
art by proposing a method for activating hydrotreating cataiyst(s), in particular
35 hydrocracking caialyst(s), that is easy to use, said method being effective in terms of
activation of hydrotreating catalyst(s), in particular of hydrocracking catalyst(s), and
offering a good compromise in ierms of controlling the risks of operator exposure, and
constraints relating to handling, storage andlor odor. Advantageously, the nitrogen
compound according to the invention employed in the method, carried out in situ, is not
CMR (carcinogenic, mutagenic, reprotoxic) according to the European CLP regulations.
5 100351 The use and the method of the present invention are quite psilicularly suitable for
the production of biofuels derived from lignocellulosic biomass and for the hydrocracking
of petroleum cuts.
DEFINITIONS
10 100361 Unless stated otherwise, the percentages mentioned are percentages by weight.
100371 "Nitrogen content by weight" means the percentage of nitrogen atoms per
molecule expressed by weight relative to the total weight of the nitrogen compound.
100381 "Room temperature" means a temperature of 20°C.
[0039] "Atmospheric pressure" means a pressure of 1.013 bar or 101325 pascal (Pa).
15 ~0040] "Alkyl polysulphides" means all the alkyl sulphides comprising at least 2 sulphide
functions per molecule.
[004l] "Dialkyl polysulphides" means all the dialkyl sulphides comprising at least 2
sulphide functions per molecule.
[00421/ "Polyarnine" means any amine compound comprising at least 2 amine functions,
20 substituted or unsubstituted, per molecule.
[0043] "AAA" means the alkylalkanolamines.
100441 "Hydrotreating activity" means the action of a catalyst for hydrotreating of
compounds.
[0045] "Hydrocracking activity" means the action of a catalyst for hydrocracking of
25 hydrocarbons.
[0046] "Tm" means melting point.
DETAILED DESCRIPTION OF THE INVENTION
[0049] According to a first aspect, the present invention relates to the use, in a method
30 for in-situ activation of at least one hydrotreating, in particular hydrocracking, catalyst, of
at least one nitrogen compound having at least one, preferably at least two, more
preferably at least three, even more preferably at least four of the characteristics as
defined above.
[0048] By using a nitrogen compound according to the invention it is possible to obtain
35 at least one, and advantageously several, of the following advantages:
- the hydrotreating, in parlicular hydrocracking, activity of the hydrotreating, in pariicuiar
hydrocraclting, catalyst is inhibited throughout the operation of sulphiding of the latter;
- the hydrotreating, in particular hydrocracking, activity of the catalyst during the
hydrotreating, in parlicular hydrocracking, operation is not diminished due to the action of
5 the nitrogen compound of the invention during the operation of sulphiding of the catalyst;
- the use of a nitrogen compound according to the invention is facilitated: compared to the
known nitrogen compounds generating less ammonia, the nitrogen compounds of the
invention do not require heavy equipment for injection;
- the risks of exposure of the operator handling the nitrogen compound of the invention
10 are reduced, relative to the known solutions such as those that employ aniline;
- advantageously, the nitrogen compound according to the invention is not CMR
(carcinogenic, mutagenic, reprotoxic) according to the European CLP regulations.
[0049] As stated above, the nitrogen compound of the invention has at least one,
preferably at least two, more preferably at least three, even more preferably at least four
15 of the characteristics a), b), c), d) defined above. All combinations are conceivable, for
example: ab, abc, ac, acd, ad, abd, bc, bcd, cd, bd, and abcd.
[0050] According to one embodiment, furthermore the nitrogen compound according to
the invention has a malecular weight in the range from 80 g.mol-' to 300 g.mol-',
preferably in the range from 100 g.mol-' to 250 g.moi-', even more preferably in the range
20 from 100 g.mol-' to 200 g.rnolP1, advantageously in the range from 120 g.mol-' to
150 g.mo1-'; designated as characteristic e) hereinafter.
[0051] According to this embodiment, the nitrogen compound has, besides characteristic
e), at least one, preferably at least two, more preferably at least three, even more
preferably at least four of the characteristics a), b), c), d) defined above. All combinations
25 are Conceivable, for example: ae, abe, abce, ace, acde, ade, abde, be, bce, ade, bcde,
cde, de, and abcde,
100521 Advantageously, the nitrogen compounds according to the invention are selected
from the nitrogen compounds comprising 2 to 20 nitrogen atoms; notably, the polyamines;
the AAAs; and mixtures thereof. For example, the diamines, the triamines, and others.
30 Preferably, the nitrogen compounds according to the invention do not comprise the
compounds derived from urea as well as the nitrated, nitrous or nitroso compounds.
[GO531 According to another preferred embodiment, the nitrogen compounds of the
invention do not contain a functional group containing an oxygen atom, such as the
hydroxyl, carboxyl, carbonyl or alkoxy group.
35 [0054] According to one embodiment, the nitrogen compound of ihe invention does not
comprise an aromaiic or cyclic group; designated as characteristic f) hereinafter.
JOQ55j According to this embodiment, the nitrogen compound has, besides characteristic
f), at least one, preferably at least two, preferably at least three, preferably at ieast four,
more preferably at least five of the characteristics a), b), c), d), e) defined above. All
combinations are conceivable, for example: af, abf, abcf, abcdf, acf, acdf, acdef, adf, adef,
5 aef, abef, abdef, acef, abef, bf, bcf, bcdf, bcdef, bdf, bdef, bef, bcef, cf, cdf, cdef, cdf, df,
def, and abcdef.
[0056] According to a preferred embodiment, characteristic b) is particularly preferred.
Thus, in a preferred embodiment, said at least one nitrogen compound has imperatively
characteristic b), i.e. said at least one nitrogen compound has a number of nitrogen atoms
10 in the range from 2 to 20, preferably in the range from 2 to 15, more preferably in the
range from 2 to 10, even more preferably in the range from 2 to 5, per molecule,
advantageously two nitrogen atoms per molecule.
j00571 According to a preferred embodiment, said at least one nitrogen compound has
characteristic b) and at least one, preferably at least two, more preferably at least three,
15 characteristics a), c), d) defined above, as well as optionally in addition characteristic e)
andlor characteristic f).
[a0581 Examples of nitrogen compounds that may be used in the present invention are:
N,NS-diethyl-l,3-propanediamine (DEAPA) (T, = -50°C), tetramethyl-l,3-propanediamine
(TMPDA) (T, = -82"C), N-methyl-1,3-propaned~amine (T, = -72"C), N,N'-dibutyl-1,3-
20 propanediamine (Tm= -50°C), N-(3-dimethylaminopropyl)propane-1,3-diamine
(DMAPAPA) (T, = -60°C), N-(3-aminopropy1)-l,3-propanediamine (T, = -16'C), N,N1-1'2 -
ethanediyl-bis-I ,3-propanediamine (Tm = -1 .Ye), N-(aminopropyl)diethanolamine
(APDEA) (T, = -20°C), and mixtures thereof.
[0059] Preferably, the nitrogen compounds are the alkylarnines selected from N,Nf-
25 diethyl-I ,3-propanediamine (DEAPA), tetramethyl-l,3-propanediamine (TMPDA),
N-methyl-I ,3-propanedlamine, N,N'-dibutyl-l,3-propanediamine,
N-(3-dimethy1aminopropyl)propane-1,3-diamine (DMAPAPA), N-(3-aminopropy1)-I ,3-
propanediarnine, N,N'-1,2-ethanediyl-bis-l ,3-propanediamine, and mixtures thereof.
/0060] More preferably, the nitrogen compounds are selected from N,N'-diethyl-1,3-
30 propanediamine (DEAPA) and tetramethyl-1.3-propanediamine (TMPDA), and the mixture
of DEAPA and TMPDA.
[006li] According to one embodiment, a mixture of at least two nitrogen compounds is
used. In the mixture of two nitrogen compounds, the nitrogen content by weight in the
mixture is equivalenl to the content of a single nitrogen compound as defined above. In
35 other words, this content is from 15 to 35 wt%, preferably from 20 to 35%, more preferably
from 20 lo 30%, and more advantageously from 20 to 25% relative to the total weight of
the mixture of nitrogen compounds.
[00621 More precisely, the following equations can be used for determining the relative
amounts of nitrogen compounds to be used so that the nitrogen content by weight of the
5 mixture complies with the invention. For a mixture of two nitrogen compounds At and A2,
their relative amounts QA, and Q Aa~re expressed as follows:
[0063] in these equations:
-A, and A2 represent two nitrogen compounds, which may be identical or different;
10 - Qhl represents the amount of the nitrogen compound Ai, expressed in wt% relative to the
total weight of the mixture of the nitrogen compounds:
- Q Az represents the amount of the nitrogen compound A*, expressed by weight relative to
the total weight of the mixture of the nitrogen compounds;
-%NAI represents the nitrogen content by weight in the nitrogen compound A?, expressed
15 in wt% relative to the weight of the nitrogen compound A,;
-%NAz represents the nitrogen content by weight in the nitrogen compound A2, expressed
in wt% relative to the weight of the nitrogen compound A2; and
- %NAI+AZ represents the nitrogen content by weight of the mixture of the two nitrogen
compounds A1 and A2 according to the invention, expressed in wt% relative to the weight
2 0 of the mixture.
100641 For example, if the nitrogen content by weight in the nitrogen cornpound A, is
%NA, =.15%, that in the nitrogen compound A2 is %NAZ = 30% and if, according to the
present invention, the target nitrogen content by weight for the mixture of Ai+A2 is
%NA~+A2~0%= , then the relative amount of the nitrogen compound A1 to be used in the
25 mixture is equal to QAI = 66.67 wt% relative to the total weight of the mixture of the
nitrogen compounds and the relative amount of the nitrogen compound A2 to be used in
the mixture is QAZ = 33.33 wt% relative to the total weight of the mixture of the nitrogen
compounds,
[0065] When the mixture comprises at least three, at least four, at least five or more than
30 five nitrogen compounds~according to the invention, equations similar to the above may
be established in order to determine the relative amounts of the nitrogen compounds to be
used so that the nitrogen content by weight of the mixture complies with the invention.
[0066] As stated above, the present invention iinaiiy relates to a method for in-.situ
activation of at least one hydrotreating, in particuiar hydrocracking, catalyst.
100671 Advantageously, said method for in-situ activation of at least one hydrotreating, in
particular hydrocraclting, catalyst consists of:
5 1) a step of sulphiding said hydrotreating, in particular hydrocracking, cataiyst, in the
presence of a sulphiding agent; and
2) a step of passivation of said hydrotreating cataiyst, in particular of said hydrocracking
catalyst, in the presence of at least one nitrogen compound as defined above.
to0681 The contacting of the hydrotreating catalyst, in particular of the hydrocracking
10 catalyst, with the nitrogen compound of the invention during said passivation step may be
carried out by any method known by a person skilled in the art, in particular by liquidphase
or gas-phase injection of the nitrogen compound of the invention into the reactor
comprising at least one hydrotreating catalyst, in particular at least one hydrocracking
cataiyst. If gas-phase injection is employed, the nitrogen compound is vaporized during
15 injection or before injection. Preferably, liquid-phase injection is employed.
[0069] Injection of the nitrogen compound of the invention may be carried out by any
means known by a person skilled in the art such as a metering pump, an injection pump,
or a feed pump.
[0070] The passivation step is advantageously carried out at a temperature in the range
20 from 120 to 350°C.
[0071] The passivation step is advantageously carried out under a hydrogen
atmosphere. The hydrogen pressure corresponds to the usual operating pressure of
hydrotreating, in particular hydrocracking, reactors. It is preferably in the range from 1 bar
to 200 bar (or from l.105 Pa to 200.10' Pa), preferably from 15 bar to 100 bar (or from
25 15.10' Pa to 100.10' Pa).
[0072] During the passivation step, the nitrogen compound is advantageously injected at
a content in the range from 0.01 to 20 wt%, preferably from 0.01 to 10 wt%, more
preferably from 0.01 to 5 wt% relative to the total weight of the hydrotreating, in particular
hydrocracking, catalyst.
30 100731 During the passivation step, the content of the nitrogen compound is
advantageously adjusted so that the ammonia content generated is from 0.01 to 40 wt%,
preferably from 0.01 to 20 a%, more preferably from 0.01 to 10 wt%, even more
preferably from 0.01 to 5% relative to the total weight of the hydrotreating catalyst, in
particular of the hydrocracking catalyst.
35 [007.$] The hydrotreating, in particular hyd~ocracking, catalyst employed in the present
invention is preferably bifunctional, having an acid function and a hydrogenating function.
This type of catalyst, known by a person skilied in the art, is generally in the form of a
supported metal. The acid function is supplied by the support (for exanipie alumina or
amorphous and/or crystalline silico-aluminate) or by halogenated dopants, such as
fliiorine for example, and the hydrogenating function is supplied by metal oxides or metal
5 sulphides, made operational by the sulphiding step.
[0075] According to one embodiment, the supports are generally porous refractory
oxides. The porous refractory oxides are preferably selected from zeolites, alumina, silica,
zirconia, and the beryllium, chromium, titanium, magnesium and thorium oxides, as well
as combinations thereof, such as silico-aluminates and silica-titanium oxide.
10 [0076] The supports most used in the field of hydrotreating, in particular itydrocracking,
are the crystalline silico-aluminates, called zeolites. The zeolites employed possess
exchangeable cations, generally metal cations or hydronium ions, preferably hydronium
ions.
I00771 The zeolites are preferably selected from the natural zeolites, for example
15 ferrierite, the artificial and synthetic zeolites such as, non-exhaustively, the zeolites ZSM,
for example ZSM-22, ZSM-23, ZSM-5, ZSM-1 I, ZSM-12, ZSM-23, ZSM-35, ZSM-38 and
their analogues, the zeolites SAPO, for example SAPO-11, SAPO-31; zeolites beta and
zeolites Y.
f0078j The porous refractory oxides may also optionally be combined with zeolites, for
20 example the combinations of zeolites with a silica, a zirconia or an alumina.
[0079] The hydrotreating, in particular hydrocracking, catalyst used in the invention
preferably comprises transition metals selected from columns 5, 6, 8, 9 and 10 of the
periodic table of the elements of the IUPAC.
[0080] Preferably, the hydrotreating, in particular hydrocracking, catalyst comprises one
25 or more transition metals selected from vanadium, niobium, tantalum, chromium,
molybdenum, tungsten, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel,
palladium, platinum and mixtures of two or more of them in all proportions.
[0081] The preferred combinations of metals are: nickel-tungsten, cobalt-molybdenum,
nickel-vanadium, nickel-molybdenum, molybdenum-tungsten and nickel-cobalt. In
30 particular, the nickelltungsten catalyst has excellent isomerization and dearomatization
properties, while displaying the capacity for performing reactions of hydrodeoxygenation
and other hydrotreating reactions, especially hydrocracking of organic raw materials,
whether they are of fossil origin (hydrocarbons derived from petroleum) or of animal or
vegetable origin.
35 [0082] These metals are generally on a support as defined above. For the
nickelftungsten catalysts, the silico-aluminate and silica-titanium oxide supports are quite
particularly suitable. These metals are in oxidized form on a suppot? sucli as an alumina
or an amorphous or cr)lstalline silico-aluminate. Preferably, the rnetal oxides are on a
zeolitic support.
[0083] The catalysts are, as nonlimiting examples, PtlSAPO-11/Al203, Pt/ZSM-Z2/AI203,
5 PtlLSM-231Alz03, NiWIA1203, NiWIzeolitelAl~O~an d PtlSAPO-11/Si02. Preferably, the
hydrotreating, in particular hydrocracking, catalyst is selected from NiWIAI203 and
NiWheolitelA1203.
[0084] It is particularly advisable to use, jointly or mixed, hydrotreating catalysts with
hydrodeoxygenation catalysts, since they both require a suiphidirig step. Thus,
10 hydrodenitrogenation, hydrodesulfurization, dearomatization, hydroconversion,
hydrogenation, hydroisomerization, hydrodeoxygenation, dearomatization and
hydrocracking may take place simultaneously, sequentially or alternately.
100851 The method for in-situ activation of the hydrotreating, in particular hydrocracking,
catalysts according to the invention comprises at least one sulphiding step, in which a
15 sulphiding agent is introduced into the hydrotreating, in particular hydrocracking, reactor.
I00861 Advantageously, the sulphiding agent is selected from hydrogen sulphide, carbon
disulphide, dimethyl disulphide (DMDS), dimethyl sulphide, mercaptans, thiophenes and
derivatives, alkyl polysulphides, dialkyl polysulphides and all sulphide compounds capable
of sulphiding the metal oxides of the hydrotreating, in particular hydrocracking, catalysts.
20 Preferably, the sulphiding agent is DMDS, notably marketed by the company ARKEMA,
for example under the trade names DMDS Evolutione and DMDS Evolution" E2.
100871 The sulphiding step may be carried out either in the gas phase or in the liquid
phase. Preferably, the sulphiding step is carried out In the liquid phase by contacting a
liquid feed comprising a light cut such as kerosene or gas oil at temperatures belween
25 120 and 350°C at a hydrogen pressure in the range from 1 bar to 200 bar (or from l.105
Pa to 200.105 Pa). Preferably, the hydrogen pressure is in the range from 15 bar to 100
bar (or from 15.'105 Pa lo 100.1O5 Pa).
[0088] More particularly, during the method for in-situ activation of the hydrotreating
catalysts, in particular hydrocracking catalysts according to the invention, after loading at
3 0 least one hydrotreating, in particular hydrocracking, catalyst, in one or more hydrotreating,
in particular hydrocracking, reactors, the liquid feed is then injected at temperatures
preferably from 120°C to 350°C. The liquid feed has a sulphide content preferably
between 0.01 and 20 wt% and preferably from 0.01 to 5 wt% relative to the total weight of
the feed.
35 [0089] According to one embodiment, after loading the catalyst, and an optional step of
drying between 120°C and 200°C ,with nitrogen or hydrogen to remove the water
adsorbed during the loading operation, the pressure of the unit is brought to the pressure
correspondirig to the usuai operating pressure of said unit, preferably between 1 bar and
200 bar (or between ?.lo5 ?a and 200.10"a), more preferably between 15 bar and 100
bar (or between 15.10Va and 100.10~a)T. he temperature of the catalytic reactors is
5 then increased in successive stages from 200°C to 350°C for carrying out the reactions of
sulphiding and of passivation of the hydroireating, in particular hydrocracking, catalysts.
[00901 In the course of the sulphiding step, the suiphiding agent is injected into the liquid
feed or the hydrogen that is supplied to the hydrotreating, in particular hydrocracking,
reactors, according to any means known by a person skilled in the art, such as a piston-
10 type metering pump, a multi-stage positive-displacement pump, or any other pumping
system providing control of the injection flow rate.
[0091] According to a preferred embodiment, the sulphiding step and the passivation
step are carried out simultaneously. In this embodiment, the sulphiding agent and the
nitrogen compound are injected into the hydrotreating, in particular hydrocracking, reactor
15 or reactors simultaneously. Mixtures comprising at least one sulphiding agent and at least
one nitrogen compound as defined above are also included.
[0092] According to another embodiment, the sulphiding step and the step of
passivation of the acid sites of the catalysts are carried out intermittently, i.e. in the
hydrotreating, in particular hydrocracking, reactor or reactors, the sulphiding agent is
20 injected and then at least one nitrogen compound according to the invention, or vice
versa, and this operation is repeated one or more times.
[0093] According to one embodiment, after activation of the hydrotreating catalyst(s), the
temperature is gradually increased in the hydrotreating reactor, to reach the usual
operating temperature of the hydrotreating reactors, in so-called productio~n mode, for
25 example between 350°C and 450°C. The compounds to be hydrotreated may be
introduced into the hydrotreating reactor under hydrogen pressure for example in the
range from 50 bar to 200 bar(or from 50.105 Pa to 200.105 Pa). The hydrogen present
desorbs the ammonia from the hydrotreating catalyst, thus allowing the catalyst to regain
all its hydrotreating activity for transforming the compounds derived from .biomass.
30 Advantageously, desorption is gradual, which makes it possible to control the exothermic
nature of the hydrotreating reaction.
I00941 According to one embodiment, after activation of the hydrocracking catalyst(s),
the temperature is gradually increased in the hydrocracking reactor, to reach the usual
operating temperature of the hydrocracking reactors, in so-called production mode,
35 preferably between 350°C and 450°C. The fraciions with heavy hydrocarbon chains to be
cracked are introduced into the hydrocracking reactor under hydrogen pressure in the
range from 50 bar to 200 bar (or from 50.105 Pa lo 200.109a). The hydi-ogen present
desorbs the arnmoriia frorn the hydrocracking cataiyst, thus allowing the cataiyst to regain
all its hydrocracking activity for converting the heavy fraction. Advantageously, desorption
is gradual, which makes it possible to control the exothermic nature of the hydrocracking
5 reaction.
E00951 The invention wiii be better understood in the light of the foliowing non-limiting
exanlples which are given for a purely iiiustrative purpose and are not intended to limit the
scope of the invention defined by the attached ciaims.
10 EXAMPLE
The objective of this test is to compare the decomposition of amines to ammonia, on
hydrotreating catalysts. The comparison is carried out between the amines according to
the invention, and the amines already described in the prior art and known in the market
as tri-n-butylamine and aniline.
15 The catalyst used for this test contains 17% by weight of molybdenum oxide and 3.5% by
weight of nickel oxide supported on a y alumina. The DMDS (dimethyl disulphide) and
DEAPA (diethylaminopropylamine) used in this test are supplied by the company
ARKEMA.
The conversion of the amines to ammonia is obtained at the outlet of the reactor
20 containing this catalyst. The catalyst must be activated by a "sulphurization" treatment
which converts the nlckei and molybdenum metal oxides into corresponding metal
sulphides. A solution of dimethyl disulphide diluted to 1.5% by weight in dodecane is used
as follows:
- 4 ml of catalyst are placed in a catalytic reactor and dried at 150°C for 1 hour under
25 nitrogen (10 NLih) at 0.5 MPa, then the nitrogen is replaced with 1 NLih of hydrogen
and the pressure in the reactor is brought to 6 MPa,
- 4 mllh of DMDS-doped dodecane (1.5% by weight) are introduced into the entering
stream of hydrogen and the temperature of the reactor is brought to 230°C according to
a temperature ramp of 25"Clh, and then stabilized at this temperature for 6 hours, said
3 0 duration being sufficient to observe a concentration of hydrogen suiphide in the
hydrogen at the reactor outlet of greater than 0.5 mol%. This hydrogen sulphide
concentration was measured on-line by gas chromatography.
- The temperature of the reactor is then increased to 350°C according to a ramp of
25"Clh and then kept at this temperature for at least 10 hours.
35
The catalyst thus activated is then brought into contact with various solutions of amines
diluted in dodecane. The ammonia concentration in the hydrogen at the outlet is
measured using the same gas chromatography apparatus. The test conditions were the
following:
5 - Flowrate of amine-doped dodecane (0.5% by weight of n~trogen)4: mlih
- Hydrogen pressure: 6 MPa
- Flowrate of hydrogen: 1 NLlh.
The temperature of the catalytic reactor was adjusted to between 200 and 300°C in
10 successive steps so as to determine the temperature required for the formation of 50% of
the expected ammonia corresponding to 50% conversion of the amine into ammonia.
Depending on the amine used, the following temperature values were obtained:
- Aniline: 256°C
- Tri-n-butyiam~ne: 254°C
15 - Diethylaminopropylamine: 245°C
These tests show the formation of ammonia at a lower temperature by virtue of the
amines of the invention, compared with the amines used in the prior art. The amine
corresponding to the criteria of the invention has a greater tendency to form ammonia on
20 contact with a nickel-based and molybdenum-based catalyst, compared with the amines
normally used in the prior art.
- 17-
CLAIMS
I. Use, in a method for in-situ activation of a hydrotreating catalyst, of at least one
5 nitrogen compound having at least two, more preferabiy at least three and even more
preferabiy at least four of the foilowing characteristics:
a) a nitrogen content by weight in the range from 15 to 35 wi%, preferably in the range
from 20 to 35%, more preferably in the range from 20 to 30%, and more advantageousiy
in the range from 20 to 25% relative to the total weight of the nitrogen compound;
10 b) a number of nitrogen atoms in the range from 2 to 20, preferably in the range from 2 to
15, more preferably in the range from 2 to 10, even more preferabiy in the range from 2 to
5, per molecule, advantageously two nitrogen atoms per molecule;
c) a boiling point in the range from 140°C to 300°C, preferably in the range from 140°C to
250°C, more preferabiy in the range from 140°C to 200°C, even more preferably in the
15 range from 140°C to 175°C; and
d) said nitrogen compound being in liquid form at room temperature and atmospheric
pressure.
2. Use according to the preceding ciaim, in which the nitrogen compound has in
20 addition a molecular weight in the range from 80 g.mo1-'-to 300 g.mo14, preferably in the
range from I00 g.mol-' to 250 g.mol-', even more preferabiy in the range from 100 g.mol-'
to 200 g.moi-', advantageousiy in the range from 120 g.moi-' to 150 g.moi"; designated as
characteristic e) hereinafter.
25 3. Use according to any one of the preceding claims, in which the nitrogen
compound has a characteristic f) such that said nitrogen compound does not comprise an
aromatic or cyclic group.
4. Use according to any one of the preceding ciaims, in which said at least one
3 0 nitrogen compound necessarily has characteristic b).
5. Use according to any one of Claims 1 to 4, in which the nitrogen compound is
selected from N,N1-diethyi-l,3-propanediamine (DEAPA), tetramethyl-l,3-propanediamine
(TMPDA), N-methyl-l,3-propanedismine, N.N'-dibutyi-l,3-propanediamine, N-(3-
35 dimethylam~nopropyi)propane-l,3-diamine (DMAPAPA), N-(3-aminopropy1)-I ,3-
propanediamine, N,N'-1,2-ethanediyl-bis-I ,3-propanediamine, N-
(aminopropyl)diethanolamine (APDEA), and mixtures thereof.
6. Use of the nitrogen compound or compounds as defined in any one of the
5 preceding claims for controlling the activity of at leas1 one hydrotreating catalyst.
7. Use of the nitrogen compound or compounds as defined in any one of Claims 1
to 4 for passivating the acid sites of the hydrotreating catalyst.
10 8. Use according to any one of the preceding claims, in a method for in-situ
activation, of at least one nitrogen compound having at least two, more preferably at least
three and even more preferably at least four of the following characteristics:
a) a nitrogen content by weight in the range from 15 to 35 wt%, preferably in the range
from 20 to 35%, more preferably in the range from 20 to 30%, and more advantageously
15 in the range from 20 to 25% relative to the total weight of the nitrogen compound;
b) a number of nitrogen atoms in the range from 2 to 20, preferably in the range from 2 to
15, more preferably in the range from 2 to 10, even more preferably in the range ftorn 2 to
5, per molecule, advantageously two nitrogen atoms per molecule;
c) a boiling point in the range from 140°C to 300°C, preferably in the range from 140°C to
20 250°C. more preferably in the range from 140°C to 200aC, even more preferably in the
range from 140°C to 175°C; and
d) said nitrogen compound being in liquid form at room temperature and atmospheric
pressure.
25 9. Use according to Claim 8, in which said at least one nitrogen compound
necessarily has characteristic b).
10. Method for in-situ activation of at least one hydrotreating catalyst comprising at
least:
30 1) a step of sulphiding said hydrotreating catalyst in the presence of a sulphiding agent;
and
2) a step of passivation of said hydrotreating catalyst in the presence of at least one
nitrogen compound as defined in any one of Claims 1 to 4.
35 21. Method according to Claim 10, in whicli the sulphiding step and the passivation
step are carried out simultaneously.
12. Method according to Claim 10 or Claim 1 I , in which the nitrogen coinpound is
injected in liquid phase or in gas phase, preferabiy in liquid phase.
5 '13. Method according to any one of Claims 10 to 12, in which the nitrogen compound
is injected at a content in the range from 0.01 to 20 wt%, preferably from 0.01 to 10 wt%,
more preferably from 0.01 to 5 wt%, relative to the total weight of the hydrotreating
catalyst.
lo 14. Method according to any one of Claims 10 to 13, in which in the sulphiding step,
the sulphiding agent is selected from hydrogen sulphide, carbon disulphide, dimethyl
disulphide (DMDS), dimethyl suiphide, mercaptans, thiophenes and derivatives, alkyl
polysulphides, dialkyl polysulphides and all sulphide compounds capable of sulphiding the
metal oxides of the hydrotreating catalysts, and preferably the sulphiding agent is DMDS.
15
15. Method for in-situ activation according to any one of Claims 10 to 14 of at least
one hydrocracking catalyst comprising at ieast:
1) a step of sulphiding said hydrocraclting catalyst in the presence of a sulphiding agent;
and
20 2) a step of passivation of said hydrocracking catalyst in the presence of at least one
nitrogen compound as defined in any one of Claims I to 5.