[0001] The present invention refers to the industrial chemistry field and in particular,
to the use of mesoporous silica functionalized with peroxycarboxylic groups as reactant
in the oxidative process of aliphatic, cycloaliphatic and aromatic organic sulphur
compounds, such as thiols, thioethers, thiophenes, specifically benzothiophene, dibenzothiophene,
methyl-and dimethyl-dibenzothiophene, diphenyl-sulphide and their derivatives. Moreover,
the invention relates to the plant for oxidation and sulphur compounds removal from
hydrocarbons fraction derived from petrol, in order to produce extra-low sulphur fuel
and sulphoxides and sulphones as by-products thereof.
[0002] As well known in the art, sulphur compounds removal is a main topic in refining and
petrochemical industry. In fact, new regulations require that fuels, their intermediate
and end products have a low content of sulphur compounds. Moreover, it is necessary
to avoid undesirable secondary reactions in order to assure the end products equality.
[0003] At present, the most widely employed process is hydrodesulphurization (HDS), which
requires the use of high temperature and pressure hydrogen stream on a catalitic bed,
with the production of H
2S. This process has a variable yield and the velocity of desulphurization greatly
slows down when it is applied to substituted thiophenic compounds, such as dibenzothiophene.
[0004] In fact, these compounds because of the sterical hindrance of benzene ring make difficult
the interaction between the molecule and the HDS catalyst; moreover, electronic density
around sulfur atom renders said compounds less available for the reduction reaction.
[0005] Recently, many procedure for desulphurization have been studied, due to the stringent
rules of many countries regarding fuels. For example, there are known "improved" plants
for HDS, which are, however, characterised by severe operating conditions, high operating
costs, lost of products' quality and fast deactivation of the catalysts used.
[0006] However, the products that are more resistant to hydrodesulphurization are sensitive
to oxidative treatments, and their removal can be achieved by processes such as oxidative
desulphurization, which is a two-step process: oxidation of sulphide and thiophenes
and the subsequent extraction of the oxidation products.
[0007] Several studies, actually under development, try to design not expensive and selective
oxidative processes, that employ environmentally-friendly, non toxic and regenerable
reactants.
[0008] Some of said processes provide the use of oxidizing agents such as nitric acid, nitrogen
oxide, organic hydroperoxides and peroxidic acids.
[0009] In literature, the most studied and spread processes are those that employ a mixture
of formic acid and hydrogen peroxide as oxiding system. Their industrial applicability
is difficult because of the liquid phase of the reactant mixture, that makes necessary
the use of liquid-liquid separator to remove the oxidized products.
[0010] WO-A-02053683 discloses an oxidative desulfurization process of thiophenes in petroleum hydrocarbons
comprising: (a) the oxidation of the feel with organic peroxides/peracids such as
peracetic acid in the presence of a catalyst such as a mesoporous siliceous solid
of silica; (b) the separation of resulting sulfones by adsorption on the catalyst
and (c) regeneration of the catalyst by washing with alcohols. Two parallel fixed
bed reactors, working alternately in oxidation/adsorption and regeneration mode, are
used.
[0011] US-A-5698326 discloses a regenerable silica-supported peracid suitable for application as heterogeneous
oxidant. The exhausted peracid oxidant is separated from the oxidizing medium by for
example filtration, washed and regenerated by peroxidation with a hydrogen peroxide/strong
acid solution.
[0012] The scope of present invention is to solve the disadvantages of the known processes,
providing the use of a solid oxidizing reactant, that is easily regenerable and environmentally-friendly.
[0013] The inventors of the present invention have surprisingly demonstrated that the use
of mesoporous silica, functionalized with peroxycarboxylic groups, according to the
procedure described by Elings et al. (1998), in comparison with the common oxidizing
systems based on organic peracids, permits to reach high velocity and higher yields
of the oxidation reaction, thanks to the quantitative utilization of the peroxycarboxylic
groups, already present.
[0014] The utilization of mesoporous silica, functionalized with peroxycarboxylic groups
in said specific field is not disclosed in literature.
[0015] Advantageously, the solid state of the reactant and its insolubility in organic mixtures
allow the easy separation of the mixture at the end of the oxidative process.
[0016] An other advantage is that the reactant is completely regenerable by means of treatment
with hydrogen peroxide at the end of the oxidative process. Moreover, its low toxicity
identifies the product as environmentally-friendly.
[0017] Due to the great industrial involvement in this field, the inventors have developed
an oxidative desulphurization process which use, for the first time, mesoporous silica
functionalized with peroxycarboxylic groups as a solid state reactant for the oxidation
of sulphur compounds.
[0018] Therefore it is object of the present invention an oxidative desulphurization process
of organic sulphur compounds for the removal of organosulphur compounds from HC fraction
and the subsequent removal or decomposition of oxidized compounds according to claim
1. The process is described as follows with reference to the attached sheets of drawings:
Figure 1 shows the Arrhenius diagram and values of energy of activation for benzothiophene
and dibenzothiophene.
Figure 2 shows the percentage of conversion of reactants into products referred to
total remaining in the eluent.
Figure 3 shows the fraction of regenerated peroxycarboxylic groups on mesoporous silica
vs time.
Figure 4 shows the functional scheme of the plant for reactive filtration.
Figure 5 shows the functional scheme of the plant for oxidation on fixed bed.
Figure 6 shows the functional scheme of the plant with reactor containing suspended
catalyst.
[0019] In order to demonstrate the applicability of the process, the inventors have carried
out experimental tests to evaluate the efficiency and the reproducibility of the process,
as described below.
Reproducibility of the oxidative reaction
[0020] At first, the reproducibility of the oxidative reaction of sulphur compounds has
been evaluated using mesoporous silica functionalized with peroxycarboxylic groups
as oxidizing agent.
[0021] Then, several samples of mesoporous silica, prepared in separate moments, have been
used in the oxidation of benzothiophene, dibenzothiophene and diphenylsulphide.
[0022] Table I shows the percentage of conversion of 936 ppm of benzothiophene, 856 ppm
of dibenzothiophene and 848 ppm of diphenylsulphide (total sulphur 518 ppm) in toluene,
undergone oxidation at 30°C with 0.5034 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table I
|
Conversion (%) |
Compound |
10 min |
30 min |
120 min |
Benzothiophene |
38 |
59 |
87 |
Dibenzothiophene |
97 |
99 |
100 |
Diphenylsulphide |
100 |
- |
- |
[0023] Table II shows the percentage of conversion of 585 ppm of benzothiophene, 418 ppm
of dibenzothiophene and 907 ppm of diphenylsulphide (total sulphur 369 ppm) in toluene
undergone oxidation at 30 °C with 0.3447 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table II
|
Conversion (%) |
Compound |
10 min |
30 min |
120 min |
Benzothiophene |
7 |
26 |
62 |
Dibenzothiophene |
70 |
93 |
100 |
Diphenylsulphide |
100 |
- |
- |
[0024] As shown in the tables, 10 minutes are sufficient to convert 100 % of diphenylsulphide,
while the conversion for thiophenic compounds is greater than 50 %.
Effects of temperature on the oxidative reaction of sulphur compounds
[0025] Secondly, has been analysed the effects of temperature on the oxidative reaction
in order to evaluate the range of applicability of the reaction and the activation
energy has been calculated for each reagent as a parameter of the reaction velocity.
[0026] Table III shows the percentage of conversion for 838 ppm of benzothiophene, 890 ppm
of dibenzothiophene and 790 ppm of diphenylsulphide (total sulphur 489 ppm) in toluene,
undergone oxidation at 30 °C with 0.4908 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table III
|
Conversion (%) |
Compound |
10 min |
30 min |
120 min |
Benzothiophene |
7 |
52 |
62 |
Dibenzothiophene |
52 |
99 |
100 |
Diphenylsulphide |
100 |
- |
- |
[0027] Table IV shows the percentage of conversion for 780 ppm of benzothiophene, 668 ppm
of dibenzothiophene and 708 ppm of diphenylsulphide (total sulphur 424 ppm) in toluene
undergone oxidation at 50 °C with 0.5044 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table IV
|
Conversion (%) |
Compound |
10 min |
30 min |
120 min |
Benzothiophene |
43 |
89 |
96 |
Dibenzothiophene |
97 |
100 |
- |
Diphenylsulphide |
100 |
- |
- |
[0028] Table V shows the percentage of conversion for 692 ppm of benzothiophene, 860 ppm
of dibenzothiophene and 744 ppm of diphenylsulphide (total sulphur 442 ppm) in toluene,
undergone oxidation at 60 °C with 0.5045 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table V
|
Conversion (%) |
Compound |
4 min |
45 min |
Benzothiophene |
45 |
91 |
Dibenzothiophene |
96 |
100 |
Diphenylsulphide |
100 |
- |
[0029] Table VI shows the percentage of conversion for 929 ppm of benzothiophene, 768 ppm
of dibenzothiophene and 835 ppm of diphenylsulphide (total sulphur 499 ppm) in toluene
undergone oxidation at 70 °C with 0.5058 g of mesoporous silica functionalized with
peroxycarboxylic groups.
Table VI
|
Conversion (%) |
Compound |
4 min |
45 min |
Benzothiophene |
54 |
81 |
Dibenzothiophene |
98 |
100 |
Diphenylsulphide |
100 |
- |
[0030] The experimental tests demonstrate that the efficiency of the reaction is satisfactory
even at low temperature.
[0031] The average values for the activation energy for the principal sulphur compounds
undergone oxidation have been calculated according to the obtained experimental data,
as shown in figure 1. Activation energy of benzothiophene: 62528 kJ/mol Activation
energy of dibenzothiophene: 62025 kJ/mol
[0032] Thus, the reaction is performed at a temperature ranging from 30 to 75 °C, where
the reactants show values of the velocity of reaction comparable with those calculated
for the conventional oxidative desulphurization systems.
[0033] Starting from said experimental results, plants schemes are provided in order to
perform the described process in the industrial level.
[0034] Therein below, three different realization forms are in detail disclosed.
A) Reactive filtration plant
[0035] In accordance with the oxidative process previously described, has been realised
a plant for the oxidative desulphurization, able to carry out a "reactive filtration",
precisely the oxidation of sulphur compounds and the contemporary removal of their
oxidized products.
[0036] The system is composed by three columns filled with a so-called mixed bed, consisting
of mesoporous silica, functionalized with peroxycarboxylic groups and a polar filtering
material (neutral alumina or neutral activated silica), working alternately (reaction,
washing, regeneration).
[0037] The steps for each column are:
- a) reaction;
- b) removal of the hydrocarbons fraction with hot nitrogen, preferably at 90 °C;
- c) washing with methanol;
- d) regeneration with hydrogen peroxide, preferably at 50 %;
- e) drying of the column with hot nitrogen, preferably at 90°C;
as shown in the scheme of figure 4.
[0038] Said plant allows to realise a "one-step" desulphurization process based on reactive
filtration, to be applied both on small and industrial productions, in a fast, cheap
and environmentally-friendly way.
[0039] Advantageously, the reactive filtration process, as previously described, can be
applied as line desulphurization filter in feed systems of internal combustion engines
and boilers.
[0040] In this case, the regeneration phase, when the filter becomes exhausted, can be carried
out in an other place.
[0041] As shown below, residence time into the column of about 4 minutes is sufficient to
ensure an optimization of the reactive filtration, and due to the regeneration step
the columns can be used in a continuous process.
COLUMN EFFICIENCY TESTS
[0042] In order to evaluate the efficiency of the present plant, the oxidation of benzothiophene,
dibenzothiophene and diphenylsulphide in different mobile liquid phases and the contemporary
removal of the oxidation products were performed in the column.
[0043] In each test the procedure was as follows: at the outlet of the column subsequent
samples of 0.5 ml volume have been taken. Some of them have been analyzed in order
to evaluate the residual quantity, percentage value compared with initial quantity,
of each sulphur product and of total sulphur. The percentage of residual sulphur in
the effluent vs the volume of the effluent itself was calculate from the obtained
data. The analysed samples are as follow: sample 1: 0 ÷ 0.5 ml; sample 2 : 1.5 ÷ 2
ml; sample 3: 3 ÷ 3.5 ml ; sample 4: 4.5 ÷ 5 ml; sample 5: 6 ÷ 6.5 ml; sample 6: 7.5
÷ 8 ml; sample 7: 9 ÷ 9.5 ml; sample 8: 10.5 - 11 ml.
[0044] The results are shown in the following tables from VII to XII.
TEST 1
[0045] Benzothiophene 740 ppm, dibenzothiophene 800 ppm and diphenylsulphide 968 ppm in
toluene (total sulphur 482 ppm) are filtered through the column filled with mesoporous
silica functionalized with peroxycarboxylic groups (0.1020 g) and neutral alumina
(1.0051 g) at the temperature of 27°C.
Table VII
Compound |
Removal (%) per sample |
1 |
2 |
3 |
4 |
5 |
Benzothiophene |
45 |
37 |
30 |
26 |
16 |
Dibenzothiophene |
89 |
84 |
83 |
77 |
56 |
Diphenylsulphide |
100 |
100 |
100 |
100 |
100 |
Sulphur |
74 |
66 |
38 |
18 |
3 |
Residual sulphur in effluent (%) |
26 |
30 |
40 |
51 |
60 |
[0046] The average residence time in the column is 4 minutes.
TEST 2
[0047] Benzothiophene 2918 ppm, dibenzothiophene 2186 ppm in isooctane (total sulphur 1076
ppm) are filtered through the column fillled with mesoporous silica functionalized
with peroxycarboxylic groups (0.5283 g) and neutral allumina (1.0045 q) at the temperature
of 27 °C.
Table VIII
|
Removal (%) per sample |
Compound |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
Benzothiophene |
99.7 |
87 |
54 |
31 |
26 |
12 |
6 |
0.4 |
Dibenzothiophene |
99.3 |
99 |
99 |
96 |
84 |
65 |
54 |
41 |
sulphur |
99.6 |
91 |
71 |
55 |
47 |
32 |
25 |
15 |
Residual sulphur in effluent (%) |
0.42 |
5.4 |
14 |
23 |
29 |
36 |
41 |
46 |
[0048] The average residence time in the column is 4 minutes.
TEST 3
[0049] Benzothiophene 2918 ppm, dibenzothiophene 2186 ppm in isooctane (total sulphur 1076
ppm) are filtered through the column filled with mesoporous silica functionalized
with peroxycarboxylic groups (0.5048 g) and silica (1.0022 g) at the temperature of
27 °C.
Table IX
|
Removal (%) per sample |
Compound |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
Benzothiophene |
99.7 |
88 |
50 |
31 |
24 |
11 |
4 |
Dibenzothiophene |
99.3 |
99 |
99 |
98 |
85 |
65 |
56 |
as sulphur |
99.6 |
92 |
68 |
55 |
47 |
30 |
23 |
Residual sulphur in effluent (%) |
0.4 |
5 |
15 |
23 |
29 |
37 |
43 |
[0050] The average residence time in the column is 4 minutes.
TEST 4
[0051] Benzothiophene 1307 ppm, dibenzothiophene 1795 ppm in decaline (total sulphur 862
ppm) are filtered through the column filled with mesoporous silica functionalized
with peroxycarboxylic groups (0.2035 g) and neutral alumina (1.0035 g) at the temperature
of 27 °C.
Table X
Sulphur compound |
Removal (%) per sample |
1 |
2 |
3 |
4 |
5 |
6 |
Benzothiophene |
97 |
77 |
28 |
16 |
8 |
2 |
Dibenzothiophene |
99 |
93 |
64 |
45 |
33 |
20 |
Sulphur |
98 |
82 |
41 |
27 |
16 |
8 |
Residual sulphur in effluent (%) |
1.8 |
11 |
29 |
41 |
50 |
58 |
[0052] The average residence time in the column is 2.5 minutes.
TEST 5
[0053] Benzothiophene 1307 ppm, dibenzothiophene 1795 ppm in decaline (total sulphur 862
ppm) are filtered through the column filled with mesoporous silica functionalized
with peroxycarboxylic groups (0.2000 g) and silica (1.0059 g) at the temperature of
27 °C.
Table XI
Compound |
Removal (%) per sample |
1 |
2 |
3 |
4 |
5 |
6 |
Benzothiophene |
98 |
76 |
24 |
22 |
8 |
2 |
Dibenzothiophene |
99 |
95 |
63 |
48 |
33 |
20 |
sulphur |
99 |
83 |
38 |
31 |
17 |
9 |
Residual sulphur in effluent (%) |
1.4 |
11 |
30 |
40 |
49 |
59 |
[0054] The average residence time in the column is 2.5 minutes.
[0055] For example, the diagram of figure 2 is based on the results obtained in test 2 and
it shows the percentage of removal of oxidized sulphur compounds and the percentage
of total residual sulphur vs effluent volume.
TEST 6
[0056] Dibenzothiophene 1150 ppm, 2methyldibenzothiophene 987 ppm, 2,4 dimethylbenzothiophene
470 ppm in decaline (total sulphur 862 ppm) are filtered through the column filled
with mesoporous silica functionalized with peroxycarboxylic groups (0.1130 g) and
neutral alumina (1.0001 g) at the temperature of 27 °C.
TABLE XII
|
Removal (%) per sample |
Compound |
1 |
2 |
3 |
4 |
5 |
Dibenzothiophene |
99.5 |
95 |
62 |
47 |
32 |
4-methyldibenzothiophene |
99.7 |
94 |
63 |
47 |
30 |
4,6- dimethyldibenzothiophene |
99.5 |
96 |
62 |
47 |
30 |
Sulphur |
99.6 |
95 |
62 |
47 |
30 |
Residual sulphur in effluent (%) |
0.4 |
3 |
16 |
26 |
35 |
[0057] The average residence time in the column is 2.5 minutes.
Regeneration of peroxycarboxylic groups on functionalized mesoporous silica
[0058] Moreover, the regenerative efficiency of the mesoporous silica has been experimentally
evaluated, by a reaction with hydrogen peroxide in order to regenerate the functional
groups from carboxylic to peroxycarboxylic groups.
[0059] In particular, the exhausted mesoporous silica with carboxylic functional groups
(1.0 g) underwent to regeneration with hydrogen peroxide at 50 % (20 ml) and methane
sulphonic acid (10 ml) and at temperature of 25 °C, knowing that the number of peroxycarboxylic
groups in the original mesoporous silica is 3.0513 mmol/g, while in the exhausted
silica is 0.0326 mmol/g.
[0060] The results are shown in table XIII and in attached figure 3.
Table XIII
Peroxycarboxylic groups (mmol/g) |
0 min |
15 min |
30 min |
60 min |
180 min |
300 min |
0.0326 |
1.9554 |
2.3194 |
2.5002 |
2.8571 |
3.0435 |
[0061] The invention provides also alternative embodiments herein described.
B) Fixed bed reactor
[0062] Said plant provides the use of a fixed bed reactor for the oxidation of sulphur compounds
to produce sulphones.
[0063] In this case, the removal of produced sulphones is carried out into an ancillary
equipment or alternatively through thermal or catalytic decomposition, with recovery
of hydrocarbons and production of SO
2 or H
2S .
[0064] The proposed system provides the use of two packed columns containing mesoporous
silica functionalized with peroxycarboxylic groups and non polar substrates, alternately
in a reaction or in a regeneration step.
[0065] The steps for each column are:
- 1. Reaction;
- 2. Removal of hydrocarbons phase with hot nitrogen, preferably at 90 °C;
- 3. Regeneration with hydrogen peroxide, preferably at 50 %;
- 4. Drying with hot nitrogen, preferably at 90 °C as shown in figure 5.
C) Suspended catalyst reactor
[0066] Is disclosed a two-step system composed by an oxidation section and a removal (or
decomposition) of oxidized sulphur compounds section.
[0067] In particular, as shown in figure 6, the oxidation is carried out in a PFR type reactor.
[0068] At the end of the reaction, the mesoporous silica functionalized is separated using
a hydrocyclone and sent to regeneration with hydrogen peroxide in acid solution.
[0069] The hydrocarbon fraction containing oxidized sulphur compounds is sent to a filtering
system, composed by two columns working alternately in adsorption and regeneration,
or it can be conveyed into a system for sulphones decomposition with recovery of organic
rings and SO
2(cracking or H
2S(HDS).
Bibliography
[0070]
- Collins F. M., Lucy A. R., Sharp C., Oxidative desulphurization of oils via hydrogen
peroxide and heteropolyanion catalysis. Journal of Molecular Catalysis 1997, 117,
397-403.
- Refining Process 2000. Flow diagrams and summary descriptions define typical licensed
processes used by modern refineries. Hydrocarbon Processing. Vol. 79 no.11 November
2000.
- Fredrick C. Sulfur reduction: What are the options?. Hydrocarbon Processing. Vol 81
no.2 February 2002.
- Babich I.V., Moulijn J.A. Science and technology of novel processes for deep desulfurization
of oil refinery streams: a review. Fuel, 2003, 82, 607-631
- Shiraishi, Y., Hirai T., Komasawa I. A Deep Desulfurization Process for Light Oil
by Photochemical Reaction in an Organic Two-Phase Liquid-Liquid Extraction System.
Ind. Eng. Chem. Res. 1998, 37, 203-211.
- Otsuki S., Nonaka T., Takashima N., Qian W., Ishihara A., Imai T., Kabe T. Oxidative
Desulfurization of Light Gas Oil and Vacuum Gas Oil by Oxidation and Solvent Extraction.
Energy & Fuels 2000, 14,1232-1239
- Tam P. S., Kittrell J. R., Eldridge J. W. Desulfurization of Fuel Oil by Oxidation
and Extraction. 1. Enhancement of Extraction Oil Yield. Ind. Eng. Chem. Res. 1990,
29, 321-324.
- Tam P. S., Kittrell J. R., Eldridge J. W. Desulfurization of Fuel Oil by Oxidation
and Extraction. 2. Modeling of Oxidation Reaction. Ind. Eng. Chem. Res. 1990, 29,
324-329.
- Te M., Fairbridge C., Ring Z. Oxidation Reactivities of Dibenzothiopenes in Polyoxometalate/H2O2
and Formic Acid/H2O2 System. Applied Catalysis A: General 2001, 219, 267-280.
- Mei H., Mei B. W., Yen T. F. A New Method for Obtaining Ultra-Low Sulfur Diesel Fuel
Via Ultrasound Assisted Oxidative Desulfurization. Fuel 2003, 82, 405-414.
- Kaluza L., Zdrazil, M., Zilkova, N. CejkaJ. High Activity of Higly Loaded MoS2 Hydrodesulfurization
Catalysts Supported on Organised Mesoporous Alumina. Catalysis Communications 2002,
3, 151-157.
- Elings J. A., Ait-Meddour R., Clark J. H., Macquarrie D. J. Preparation of a Silica-Supported
Peroxycarboxylic Acid and Its Use in the Epoxidation of Alkenes. Chem. Commun., 1998,
2707-2708.
- Macquarrie D. J. Organically Modified Hexagonal Mesoporous Silicas. Green Chemistry,
August 1999, 195-198.
Clark J. H., Elings S., Wilson K. Catalysis for Green Chemistry: Ultrahigh Loaded
Mesoporous Solid Acids. C. R. Acad. Sci. Paris, Serie Iic, Chimie/Chemistry, 2000,
3, 399-404.
1. Prozess zur oxidativen Entschwefelung organischer Schwefelverbindungen zum Entfernen
von organischen Schwefelverbindungen aus einer HC-Fraktion und zum anschließenden
Entfernen oder Zersetzen der oxidierten Verbindungen,
dadurch gekennzeichnet, dass:
a) die Oxidation durch mesoporose Kieselerde erfolgt, die mit regenerierbaren Peroxycarboxyl-Gruppen
in einem PFR-Reaktor (plug-flow reactor) funktionalisiert wird;
b) am Ende der Reaktion die funktionalisierte mesoporose Kieselerde mittels eines
Hydrozyklon abgeschieden und zur Regenerierung mit Wasserstoffperoxid transportiert
wird;
c) die die oxidierten Schwefelverbindungen enthaltende Kohlenwasserstofffraktion zu
einem Entfernungssystem transportiert wird, das aus zwei mit polar adsorbierenden
Material gefüllten Säulen besteht, die abwechselnd in Adsorptions- oder Regenerationsphasen
arbeiten, oder zu einem Zersetzungssystem mit der Rückgewinnung organischer Ringe
und der Produktion von SO2 (Cracken) oder H2S (Hydro-Entschwefelung).
2. Prozess zur oxidativen Entschwefelung organischer Schwefelverbindungen und anschließendes
Entfernen oder Zersetzen der oxidierten Verbindungen nach Anspruch 1, dadurch gekennzeichnet, dass
die erschopfte mesoporose Kieselerde in saurer Losung regeneriert wird.
3. Prozess zur oxidativen Entschwefelung organischer Schwefelverbindungen und anschließende
Entfernung oder Zersetzung der oxidierten Verbindungen nach Anspruch 1, dadurch gekennzeichnet, dass
die Oxidationsprodukte als Sulfoxide und Sulfone durch eine adsorbierende polare Schicht
entfernt werden.
4. Prozess zur oxidative Entschwefelung organischer Schwefelverbindungen und anschließende
Entfernung oder Zersetzung der oxidierten Verbindungen nach Anspruch 3, dadurch gekennzeichnet, dass
die adsorbierende polare Schicht aus Tonerde besteht.
5. Prozess zur oxidativen Entschwefelung organischer Schwefelverbindungen und anschließende
Entfernung oder Zersetzung der oxidierten Verbindungen nach Anspruch 3, dadurch gekennzeichnet, dass
die absorbierende polare Schicht aus Kieselerde besteht.
6. Prozess zur oxidativen Entschwefelung organischer Schwefelverbindungen und anschließende
Entfernung oder Zersetzung oxidierter Verbindungen nach Anspruch 3, dadurch gekennzeichnet, dass
die adsorbierende polare Schicht aus Alumosilikaten von Alkali- oder Erdalkalimetallen
besteht.
1. Procédé de désulfurisation oxydante des composés sulfurés organiques pour l'élimination
des composés organosulfurés provenant d'une fraction d'hydrocarbure et l'élimination
ou la décomposition ultérieure des composés oxydés,
caractérisé en ce que
a) l'oxydation est réalisée par de la silice mésoporeuse fonctionnalisée avec des
groupes peroxycarboxyliques pouvant être régénérés dans un réacteur PFR ,
b) à la fin de la réaction, la silice mésoporeuse fonctionnalisée est séparée en utilisant
un hydrocyclone et envoyée vers une régénération avec du peroxyde d'hydrogène ;
c) la fraction d'hydrocarbure contenant les composés sulfurés oxydés est envoyée vers
un système d'élimination, composé de deux colonnes et rempli d'un matériau polaire
adsorbant, fonctionnant alternativement en phases d'adsorption et de régénération,
ou vers un système de décomposition avec la récupération des cycles organiques et
la production de SO2 (craquage) ou d'H2S (hydro désulfurisation).
2. Procédé de désulfurisation oxydante des composés sulfurés organiques et l'élimination
ou la décomposition ultérieure des composés oxydés, selon la revendication 1, caractérisé en ce que la silice mésoporeuse épuisée est régénérée dans une solution acide.
3. Procédé de désulfurisation oxydante des composés sulfurés organiques et l'élimination
ou la décomposition ultérieure des composés oxydés, selon la revendication 1, caractérise en ce que les produits d'oxydation, tels que les sulfoxydes et les sulfones, sont éliminés
par un lit polaire adsorbant.
4. Procédé de désulfurisation oxydante des composés sulfurés organiques et l'élimination
ou la décomposition ultérieure des composés oxydés, selon la revendication 3, caractérisé en ce que le lit polaire adsorbant est de l'albumine
5. Procédé de désulfurisation oxydante des composés sulfurés organiques et l'élimination
ou la décomposition ultérieure des composés oxydés, selon la revendication 3, caractérisé en ce que le lit polaire adsorbant est de la silice
6. Procédé de désulfurisation oxydante des composés sulfurés organiques et l'élimination
ou la décomposition ultérieure des composés oxydés, selon la revendication 3, caractérisé en ce que le lit polaire adsorbant est de l'aluminosilicate de métaux alcalins ou alcalino-terreux.