OA17885A

OA17885A - Process for the refining of crude oil.

Info

Publication number: OA17885A
Application number: OA1201300161
Authority: OA
Inventors: Fernando Rispoli Giacomo; Bellussi Giuseppe
Original assignee: Eni S.P.A.
Priority date: 2010-10-27
Filing date: 2011-10-27
Publication date: 2018-02-27

Abstract

A process for the refining of crude oil, comprising a separation unit of the crude oil, consisting of at least one atmospheric distillation unit for separating the various fractions, a unit for the conversion of the heavy fractions obtained, a unit for improving the quality of some of the fractions obtained by actions on the chemical composition of their constituents, and units for the removal of undesired components, characterized in that the heaviest fraction, the atmospheric distillation residue, is sent to the conversion unit comprising a hydroconversion reactor in slurry phase or of the ebullated bed type, into which hydrogen or a mixture of hydrogen and ¾S is introduced in the presence of a suitable nanodispersed hydrogenation catalyst.

Description

The présent invention describes a process for the refining of oil crude in which the séparation unit of the crude oil consists of the atmospheric distillation column only, the sub-atmospheric distillation column being substituted with a hydroconversion step.

Current refineries were conceived starting from demands which were generated in the last century straddling the Second World War and evolved considerably starting from the years 1950 - 1960 when the significant increase in the request for mobility caused a rapid increase in the demand for gasoline. Two refining schemes were therefore developed, a simple cycle scheme or Hydroskimming and a complex scheme (La raffinazione del petrolio” (oil refining), Carlo Giavarini and Alberto Girelli, Editorial ESA 1991). In both schemes, the primary operations are the same: the crude oil is pretreated (Filtration, desalination), then sent to the primary distillation section, In this section, the crude oil is first fed to a distillation column at atmospheric pressure (Topping) which séparâtes the lighter distillâtes, whereas the atmospheric residue is transferred to a sub-atmospheric distillation column (Vacuum) which séparâtes the heavy distillâtes from the vacuum residue. in the simple cycle scheme, the vacuum residue is substantially used for the production of bitumens and fuel oil. The complex cycle scheme was conceived for further converting the bottom ofthe barrel to distillâtes and for maximizing the production of gasoline and its octane content. Units were therefore added for promoting the conversion of the heavier fractions (Various Catalytic Cracking, Thermal cracking, Visbreaking, Coking technologies) together with units for promoting the production of gasoline having a maximum octane content (Fluid Catalytic Cracking, Reforming, Isomerization, Alkylation).

Figure 1 shows a simplified block scheme of a complex cycle refinery whose description is provided in Comparative example 1.

With respect to the period in which these schemes were conceived, there has been an enormous variation in the surrounding scénario. The increase in the price of crude oils and environmental necessities are pushing towards a more efficient use of fossil resources, Fuel oil, for example, has been almost entirely substituted by natural gas in the production of electric energy. It is therefore necessary to reduce or eliminate the production of the heavier fractions (Fuel oil, bitumens, coke) and increase the conversion to medium distillâtes, privileging the production of gasoil for diesel engines, whose demand, especially in Europe, has exceeded the request for gasoline. Other important change factors consist in the progressive détérioration in the quality of crude oils available and in the quality increase of fuels for vehicles, imposed by the regulatory évolution for reducing environmental impact. The pressure of there requirements has caused a further increase in the complexity of refineries with the addition of new forced conversion technologies: hydrocracking at a higher pressure, gasification technologies of the heavy residues coupled with the use of combined cycles for the production of electric energy, technologies for the gasification or combustion of coke oriented towards the production of electric energy.

The increase in the complexity led to an increase in the conversion efficiency, but increased energy consumptions and made operative and environmental management more difficult. New refining schemes must therefore be found which, although satisfying the new demands, allow a recovery of the efficiency and operative simplicity.

In the last twenty years, important efforts hâve been made for developing hydrocracking technologies capable of completely converting heavy crude oils and sub-atmospheric distillation residues into distillâtes, avoiding the coproduction of fuel oil and coke. An important resuit in this direction was obtained with the development of the EST technology (Eni Slurry Technology) described in the following patent applications:

IT-MI2004A002445, IT-MI2004A002446, IT-MI2006A001512, IT-MI2006A001511, 1T-MI2007A001302, ITMI2007A001303, IT-MI2007A001044, IT-MI2007A001045, IT-MI2007A001198, IT-MI2008A001061.

With the application of this technology, it is in fact possible t reach the desired total conversion resuit of the heavy fractions to distillâtes. It has now been found that, by substituting the sub-atmospheric distillation section with a hydroconversion section according to said EST technology, a new refinery scheme can be obtained which, although allowing the total conversion ofthe crude oil, is much simplerand advantageous from an operative, environmental and economical point of view. The application of the process claimed allows a réduction in the number of unitary operations, storage tanks of the raw materials and semi-processed products and consumptions, in addition to an increase in the refining margins with respect to a modem refinery, used as reference.

The process claimed allows to obtain the total conversion ofthe crude oil fed, to gas, Naphtha, and gasoil having a modest quantity of tars as single by-product.

The process, object of the présent invention, for the refining of crude oil comprising a unit for separating crude oil, consisting of at least one atmospheric distillation unit for separating the various fractions, units for the conversion of the heavy fraction obtained , units for improving the quality of some of the fractions obtained by actions on the chemical composition of their constituents, and units for the removal of undesired components, is characterized in that the heaviest fraction, the atmospheric distillation residue, is sent to the conversion unit comprising at least one hydroconversion reactor in slurry phase or of the ebullated bed type, into which hydrogen or mixture of hydrogen and H2S is introduced in the presence of a suitable nanodispersed hydrogénation catalyst.

Said conversion unit substitutes the sub-atmospheric distillation section.

The sub-atmospheric distillation section constitutes with the atmospheric distillation unit the séparation unit in the current refineries.

The term nanodispersed means a dispersed catalyst having dimensions in the order of units to hundreds of nanometers.

The nanodispersed hydrogénation catalyst can be based on Mo sulfide and/or Fe and/or W and/or Cr and can be formed in situ, starting from a precursor. A co-catalyst can also possibly be présent in the hydroconversion, said co-catalyst having particles of nanometric or micronic dimensions, selected from cracking and/or denitrogenation catalysts, such as zeolites having small-sized crystals and with a low aggregation degree between the primary particles, oxides, sulfides or precursors of Ni and/or Co, mixed with Mo and/or W. further details on the use of said co-catalyst can be found in the above-mentioned patent application IT-MI2008A001061.

The reactor used in the présent invention is preferably run under hydrogen pressure or a mixture of hydrogen and hydrogen sulfide, ranging from 100 to 200 atmosphères, within a température range of 350 to 480°C, preferably ranging from 380 to 450°C. although any hydroconversion process can be used, effected with hydroconversion reactors in slurry phase in which the catalyst is nanodispersed, and in particular ail processes of the EST technology described in the patent applications cited above, it is préférable to use the processes ofthe EST technology indicated hereunder.

Preferred hydroconversion processes are those ofthe EST technology in which solid accumulation reactors are adopted as hydroconversion reactors. One of these preferred processes comprises sending the distillation residue to a solid accumulation hydroconversion reactor (RIAS), preferably a bubble tower, which includes one or more stripping phases with a suitable hot stripping gas so as to obtain the conversion products in vapour phase. Further details on this spécifie hydroconversion process can be found in patent application IT-MI2007A001044 indicated above.

Another of these preferred processes comprises sending the distillation rsidue to a solid accumulation hydroconversion reactor of the bubbling tower type in the presence of a catalyst based on molybdenum so as to obtain the hydroconversion products in vapour phase directly at the reactor. Further details on this spécifie hydroconversion process can be found in patent application IT-MI-2007A001044already indicated above.

A further preferred hydroconversion process in which a dénitrification also takes place, comprises sending the distillation residue to a hydroconversion reactor, where the products having a boiling point higherthan 380°C, obtained by partial condensation ofthe gas phase leaving'said reactor, before or after séparation of the non-converted asphaltene liquid, and possibly obtained by extraction under vacuum of the asphaltene liquid itself before being recycled to the reactor, are send back to said hydroconversion reactor, so that the conversion products extracted can be distilled for at least 60% by weight at 380°C. This dénitrification and hydroconversion process is described in patent application IT-M12010A001989 of the same applicant of which the most significant details are provided.

The process, claimed in said patent application, for the dénitrification are hydrocracking of heavy oils to totally converted products, which comprises sending the heavy oil to a hydrocracking step, effected in an appropriate reactor with a suitable hydrogénation catalyst and with the introduction of hydrogen or a mixture of hydrogen and H2S, is characterized by sending the products having a boiling point higher than 380°C, obtained by partial condensation of the gas phase leaving the reactor before or after séparation of the non-converted asphaltene liquid, and possibly obtained by vacuum extraction of asphaltine liquid itself before being recycled to the reactor, back to the hydrocracking reactor, so that the reconversion products extracted can be distilled for at least 60%, preferably at least 80%, more preferably at least 95%, even more preferably at least 99%, by weight at 380°C. by regulating the conditions of said partial condensation and possibly the reflux conditions at the vacuum column which extracts the products from the nonconverted asphaltene liquid, the quantity of high-boiling products is determined, which are sent back to the hydrocracking step and, complementarily, the fraction of hydroconverted product which is vice versa extracted.

This process, which enables high concentrations of nitrogenated tails to be kept in reaction, even when operating under high-temperature conditions, allows the extraction of products having a low nitrogen content and with a complété conversion degree (95% of distillable product at 380°C) which can be fed directly to the desulfurization unit.

The hydrogénation catalyst is preferably based on molybdenum, more preferably in slurry phase, and can be a decomposable precursor or preformed compound and can possibly contain additionally one or more transition metals. The reactor used is preferably run under hydrogen pressure or a mixture of hydrogen and hydrogen sulfide, ranging from 100 to 200 atmosphères, within .a température range of 400 to 480°C. The présent invention can be applied to any type of hydrocracking reactor, such as a stirred tank reactor or preferably a slurry bubbling tower. The slurry bubbling tower, preferably of the solid accumulation type (described in the above patent application IT-MI2007A001045), is equipped with a reflux loop, whereby the hydroconversion products obtained in vapour phase are partially condensed and the condensate sent back to the hydrocracking step. Again, in the case ofthe use of a slurry bubbling tower, it is preferably for the hydrogen to be fed to the base of the reactor through a suitably designed apparatus (distributor on one or more levels) for obtaining the best distribution and the most convenient average dimension of the gas bubbles and consequently a stirring régime which is such as to guarantee conditions of homogeneity and a stable température control even when operating in the presence of high concentrations of solids, produced and generated by the charge treated, when operating in solid accumulation. If the asphaltene stream obtained after séparation of the vapour phase is subjected to distillation for the extraction of the products, the extraction conditions must be such as to reflux the heavy cuts in order to obtain the desired conversion degree.

With respect to hydroconversion processes using ebullated bed reactors, in addition to the nanodispersed hydrogénation catalyst, the presence of a suitable supported heterogeneous hydroconversion catalyst is also necessary. In this case, the hydroconversion'process comprises sending the distillation residue to one or more ebullated bed hydroconversion reactors, into which hydrogen or H2S is introduced and sending the effluent stream from said reactor(s) to a séparation step in which the liquid fraction separated and containing the nanodispersed catalyst is recycled to said ebullated bed reactor(s). Further details on the process using ebullated bed reactors and supported hydroconversion catalysts can be found in the already mentioned patent application IT-MI2007A001198.

EXAMPLES

Some examples are provided hereunder, which help to better define the invention without limiting its scope. An actual complex-cycle modem refinery, optimized over the years for reaching the total conversion of the feedstock fed, has been taken as reference.

The reference feedstock, used for examples 1, 2,3 is the following (in kton/month):

BTZ FEEDSTOCKS (38°API, 0.16%S)	248.7
-AMNA (37°API, 0.13%S)		38.8
-AZERI (36°API,0.17%S)		150.4
-CPC BLEND (44°API, 0.16%S)	11.0
-OTHERS		27.4

ATZ FEEDSTOCKS (33°API, 1.3%S)482.3

-IRANIAN LIGHT (33°API, 1.5%S)35.5

-URAL (32°API, 1.4%S)346.8

-CPC BLEND (44°API, 0.22%S)61.0

-OTHERS

39.0

Total

731.0

The material balances and consumptions of the EST section corresponding to the simplified block schemes provided in examples 1, 2, 3 and 4 relate to the configuration using hydroconversion reactor(s) with the recirculation and extraction of products in vapour phase (160 bar, 440°C), using nanodispersed catalysts based on molybdenite and in accordance with the information provided in the above-mentioned patent applications.

Input

Hydrogen (415, 5 ton/d) 4%

193900 Nm³/h

Atmospheric residue 100%

Output

Fuel gas (571 ton/d) 5.5%

GPL (1329 ton/d) 12.8%

Naphtha L. (689 ton/d) 13.5% to isomérization

Naphtha H. (1378 ton/d) 13.3% to reforming

Gasoils (6700 ton/d) 64.5% to desulfurization

Purge (135ton/d) 1.3%

Consumptions: 77 kgEP/ ton (including H2), of which:

MP steam 7.7, HP Fuel Gas 79,4, LP Fuel Gas-107.3, EE-56,8

Platt’s data available from for the month of July 2010 were used for the upgrading of the products, whereas the Eni reference values, indicated in Table 1 were used for the unfinished products.

Table 1: Upgrading of products

Products	FOB €/ton
Syn gas<²)	99.7
Fuel gas®	493.7
LPGG)	489.7
RON 95 gasolineO)	556.8
Jet AK¹)	538.3
Auto gasoil·¹)	557.6
F.O..DATZ<¹)	335.3
F.O..D BTZd)	336.6
Solid sulfur (²)	1.5
ATZ atm. Res.P)	360.7
MTBE(2)	645.0
Virgin naphtha FR0)	485.9
catFeedt²)	445.8
Pitchi²)	71.9
Scénario July 2010 O)p\|att source: quota	tion Avg FOB Med; GPL; propane
70%, butane 30%, FOB Algeria (²)Source Eni-R&M- Exchange rate 1€ =
1.2328$

Example 1 (comparative)

In this example, the simplified block scheme is provided of an existing complex-cycle refinery situated in Northern Italy with the average quantities and material balances in the month of June 2010 (Figure 1). This refinery has forced conversion units, such as FCC, Visbreaking and residue gasification and is oriented towards the total conversion ofthe crude oil.

Toppinq plant

The mixture of ATZ and BTZ crude oils, desalted and preheated, is sent to the topping plant for atmospheric fractionation, obtaining, in addition to fuel gas and LPG, the following products:

- Light Virgin Naphtha (LVN): this is desisopentanized in the De-isopenta plant and subsequently processed in the Isomerization plant (TIP). The isomerized product flows into the gasoline pool.

- Virgin Naphtha Charge Reformer (VNCR): this is a heavier Naphtha than the previous one processed in the Reforming plant RC2. The light fraction obtained in a LVN which is processed in the TIP plant, whereas the heavy fraction is the reformate which goes to the gasoline pool.

- Kero: the stream is sent to the desulfurization units HDS1 and HDS3, obtaining desulfurized kero which goes to end-products.

- Topping gasoil: the stream is sent to the desulfurization units HDS1 and HDS3, obtaining desulfurized gasoil which goes to end-products.

- Atmospheric residue (RA): this is processed in the Vacuum plant.

Vacuum plant

The plant receives the atmospheric residue (AR) and subjects it to a vacuum distillation process. In addition to gaseous products, vacuum gasoil (LGAS) is obtained, which is desulfurized in the unit HDS1 and then goes to end-products, together with catfeed or deep-vacuum (DPV) sent to the conversion plants of Hydrocracking and FOC. The Vacuum residue (RV) is then processed in the Visbreaking unit. Visbreakinq unit

This converts the Vacuum residue (VR) to gaseous products (fuel gas, propane, butane, etc.) and Virgin Naphtha which is subsequently processed in the Reformer unit RC3: the reformate obtained goes to the gasoline pool. The Visbreaking gasoil and catfeed are processed by the Hydrocracking and FCC plants, whereas the residue (TAR VB) is partly destined for the production of F.O. (Fuel Oil) and bitumens and partly subjected to a de-asphalting process.

Hydrocracking plant

The refinery has two Hydrocracking plants. The first HDC has Vacuum catfeed (DPV) and Visbreaking catfeed, Visbreaking gasoil and other semi-processed products, as input streams. Gaseous products (fuel gas, propane, butane, etc.) both light and heavy Virgin Naphtha, kero and desulfurized gasoil are obtained, which go to end-products.

The Virgin Naphtha undergoes the same processings described above, flowing into the gasoline pool.

The residue (BOT HDC) forms the input stream for the second HCD together with Vacuum catfeed (DPV). The products are the same as those in the first HDC.

For the sake of simplicity the two HDC units are represented as a single HDC, into which the residue (BOT HDC) is sent for conversion to FCC.

Desulfurization Plants

The refinery in the example is equipped with three distinct desulfurization plants (HDS), used for satisfying the sulfur spécifications. The main streams in the feeding to these units are Kero, Gasoil, LCO. De-asphaltinq Plant

This is fed by the Visbreaking residue (TAR VB). The output streams consist of de-asphalted oil (DAO), subsequently processed in the FCC, and asphaltenes which are fed to the gasification plant (Partial Oxidation POX) to produce syngas. The syngas obtained is destined for the electric supply network for the production of energy and also for the production of hydrogen.

FCC Plant

This is fed by DAO coming from the De-Asphalting plant, Visbreaking catfeed, the HDC residue (BOT HDC) and atmospheric residue (RA).

The products obtained in addition to gas, are propylene, butylène and cracked Naphtha (LCN,

MON, HCN) sent to the gasoline pool.

LCO is also obtained, which is desulfurized in the HDS2 plant and sent to the gasoil pool, together with HCO used a fluxing agent for bitumen and FO.

ETBE Plant

The plant is charged with purchased bioethanol and with isobutylenes in order to obtain bioETBE to be sent to the alkylation plant (ALK) whose output, the aikylated products, flows into the gasoline pool.

DEISOPENTA Plant

The purpose of this plant is to separate the isopenta from the LVN stream and send it to the gasoline pool. The deisopentanized LVN is sent to the Isomerization plant.

Reforming Plant

The purpose of the two reforming plants (RC) is to increase the octane number of the heavy

Virgin Naphtha producing Reformate which is sent to the gasoline pool and at the same time hydrogen for the refinery. The refining cycle described also envisages, in addition to the crude oils at the input, the use of semi-processed products which can be used for the optimization of the same cycle, purchased or stored in the refinery, consisting in atmospheric residue, MTBE to bring the gasoline pool and catfeed up to spécification requirements.

The following tables respectively indicate the capacity available/percentage of use (Table 2) and the material balance ofthe products (table 3):

Table 2: Capacity/ use

Kton/month; % use	Base case Ex.1
CDU	731.0(100%)
VDU	327.0(78%)
Gasoil HDS 1	46.0100(%)
Kero HDS 1	16.8(100%)
HDS 2	144.0(100%)
HDS 3	72.0(100%)
EST
Reforming 2	57.0(100%)
Reforming 3	75.0(100%)
Isomerization	41.1(100%)
Hydrogen	6.0
Alkylation	17.7(57%)
ETBE	3.6(57%)
FCC	159.0(60%)
Hydrocracker 1	115.2(100%)
Hydrocracker 2	115.2(100%)
Visbreaker	153.0(73)
B DA	48.0 (100%)
Gasification	36.0 (100%)

Table 3: Material Balance

Products Kton/month	742.1
Syn gas	35.7
Fuel gas
LPG	17.9
Gasoline	213.6
Virgin Naphtha FR	13.6
Kero	79.0
Gasoils	344.2
O.C. ATZ /Pitch	24.9
O.C. BTZ	7.3
Sulfur	5.9
Feedstock Kton/month	792
Mix crude oils	731.0
Atm. Residue	7.5
MTBE	8.1
CatFeed	45.4
Total C&P	49.9
Consumptions	44.3
Losses	5.7

The relative économie margins are indicated in Table 4.

Table 4: Economie resuit

M €/month	Base case Ex.1
Yields from products	383.3
Syn gas	3.6
Fuel gas
LPG	8.8
Gasoline	118.9
Virgin Naphtha FR	6.6
Kero	42.5
Gasoils	191.9
F.O. ATZ/Pitch	8.3
F.O. BTZ	2.7
Sulfur	-
Cost crude oil and S/L	336.4
Raw material cost	28.1
Atm. Residue (AR)	2.7
MTBE	5.2
CatFeed	20.2
Total crude oil MP	364.5
Operative gross margin	18.8

Example 2 (High-efficiency refinery, HER, oriented towards Gasoline, Kerosene and Gasoils).

The reference scheme for this case is indicated in Figure 2. With respect to the complex-cycle refinery, the sub-atmospheric distillation section was substituted by a reactor with the EST technology, described in patent application IT-MI2010A001989 already mentioned above, suitably dimensioned for receiving ail the atmospheric residue feedstock (AR).

For the streams leaving the topping plant, the previous description of the complex-cycle refinery can be applied. The output streams from the EST section, comprising one or more hydroconversion units and séparation and purge units ofthe products, consist ofthe C4-fraction for the production offuel gas and

LPG, Light Virgin Naphtha (LVN), Heavy Virgin Naphtha (HVN), gasoil and modest quantity of purge.

Whereas the gasoil is sent to the desulfurization unit and subsequently to gasoil pools, the light naphtha is treated in the Isomerization plant from which the isomerate is obtained, and the heavy Naphtha in the reformer from which the reformate is obtained. The isomerate and reformate flow into the gasoline pool. The capacity of the desulfurization plants HDS2 and HDS3, the Isomerization plant and Reforming plant RC3 was suitably increased to receive the streams coming from the EST plant.

The following tables respectively indicate the capacity available/percentage of use (Table 5) and the material balance ofthe products (Table 6):

Table 5: Capacity/use

Kton/month; % use	Base case Ex.1	HER Ex. 2
CDU	731.0(100%)	731.0(100%)
VDU	327.0(78%)
Gasoil HDS 1	46.0(100%)	46.0(100%)
Kero HDS 1	16.8(100%)	16.8(100%)
HDS 2	144.0(100%)	347.0 (100%)
HDS 3	72.0(100%)	76.0 (100%)
EST		324.1 (100%)
Reforming 2	57.0(100%)	57.0(100%)
Reforming 3	75.0(100%)	84.3(100%)
Isomerization	41.1(100%)	67.1(100%)
Hydrogen	6.0	12.5
Alkylation	17.7(57%)
ETBE	3.6(57%)
FCC	159.0(60%)
Hydrocracker 1	115.2(100%)
Hydrocracker 2	115.2(100%)
Visbreaker	153.0(73)
BDA	48.0 (100%)
Gasification	36.0(100%)

Table 6: Material Balance

	Base case Ex.1	HERx2	Variât. %
Products Kton/month	742.1
Syn gas	35.7
Fuel gas		18.1
LPG	17.9	48.6	171%
Gasoline	213.6	167.1	-22%
Virgin Naphtha FR	13.6
Kero	79.0	87.4	+11%
Gasoils	344.2	371.6	+8%
F.O. ATZ/Pitch	24.9	3.1
F.O. BTZ	7.3
Sulfur	5.9	6.6
Feedstock Kton/month	792	731
Mix crude oils	731	731
Atm. Residue	7.5
MTBE	8.1
CatFeed	45.4
C&P	49.9	28.5	43%
Consumptions	44.3	24.3	-45%
Losses	5.7	4.2	-25%

The économie data indicated in Table 7 dérivé from these material balances.

Table 7: Economie resuit

M €/month	Base case Ex.1	HER Ex. 2
Yields from products	383.3	380.3
Syn gas	3.6
Fuel gas		8.9
LPG	8.8	23.8
Gasoline	118.9	93.1
Virgin Naphtha FR	6.6
Kero	42.5	47.1
Gasoils	191.9	207.2
F.O. ATZ/Pitch	8.3	0.2
F.O. BTZ	2.7
Sulfur	—
Cost crude oil and S/L	336.4	336.4
Raw material cost	28.1
Atm. residue	2.7
MTBE	5.2
CatFeed	20.2
Total crude oil MP	364.5	336.4
Operative gross margin	18.8	43.8
Δ Margin		+ 25.1
€/ ton		+ 34.4

Example 3 (High-efficiency refinery, RAE, oriented towards Virgin Naphtha, Kerosene and Gasoils).

ln this case, the refinery scheme is even simpler and is provided in Figure 3. It comprises the same

EST section as Example 2 cited above from which the same streams are discharged, and functioning under the same operative conditions. As the VN, both light and heavy, is used totally for petrochemistry, 11 the Isomerization and Reforming units are no longer necessary. This leads to a considérable plant simplification with a conséquent réduction in the relative investment.

The following tables respectively indicate the capacity available/percentage of use (Table 8) and the material balance of the products (Table 9):

Table 8: Capacity /use

Kton/month; % use	Base case Ex.1	HER Ex. 2
CDU	731.0(100%)	731.0(100%)
VDU	327.0(78%)
Gasoil HDS 1	46.0(100%)	46.0(100%)
Kero HDS 1	16.8(100%)	16.8(100%)
HDS 2	144.0(100%)	347.0 (100%)
HDS 3	72.0(100%)	76.0 (100%)
EST		324.1 (100%)
Reforming 2	57.0(100%)
Reforming 3	75.0(100%)
Isomerization	41.1(100%)
Hydrogen	6.0	12.5
Alkylation	17.7(57%)
ETBE	3.6(57%)
FCC	159.0(60%)
Hydrocracker 1	115.2(100%)
Hydrocracker 2	115.2(100%)
Visbreaker	153.0(73)
BDA	48.0(100%)
Gasification	36.0 (100%)

Table 9: Material Balance

	Base case Ex.1	HER Ex 2	Variai %
Products Kton/month	742.1	707.8
Syn gas	35.7
Fuel gas		7.9
LPG	17.9	35.5	98%
Gasoline	213.6
Virgin Naphtha FR	13.6	195.7
Kero	79.0	87.4	+11%
Gasoils	344.2	371.6	+8%
F.O. ATZ/Pitch	24.9	3.1
F.O. BTZ	7.3
Sulfur	5.9	6.6
Feedstock Kton/month	792	731
Mix crude oils	731	731
Atm. Residue	-7.5
MTBE	-8.1
CatFeed	-45.4
C&P	49.9	23.2	-53%
Consumptions	44.3	19.6	-56%
Losses	5.7	3.6	-36%

The économie data indicated in Table 10 dérivé from these material balances.

Table 10: Economie resuit

M €/month	Base case Ex.1	HER Ex. 2
Yields from products	383.3	370.9
Syn gas	3,6
Fuel gas		3.9
LPG	8.8	17.3
Gasoline	118.9
Virgin Naphtha FR	6.6	95.1
Kero	42.5	47.1
Gasoils	191.9	207.2
F.O.ATZ/Pitch	8.3	0.2
F.O. BTZ	2.7
Sulfur	...
Cost crude oil and S/L	336.4	336.4
Raw material cost	28.1
Atm. residue	2.7
MTBE	5.2
CatFeed	20.2
Total crude oil MP	364.5	336.4
Operative gross margin	18.8	34.4
Δ Margin		+15.7
€/ ton		+21.5

This example shows that also in the case of a refinery oriented towards Virgin Naphtha for chemistry and gasoils, a high increase in margin is obtained with respect to the base case, even though the complexity, the number of unit operations and consequently the investments required hâve been further reduced, also with respect to Example 2.

Example 4

The presence of EST allows the refinery to accept heavier feedstocks than those normally processed by a modem complex-cycle refinery and this opportunity further improves the économie returns. The refinery illustrated comprises the same EST SECTION AS Example 2 above, from which the same streams are discharged, and functioning under the same operative conditions. This example provides the results obtained from a high-efficiency refinery oriented toward producing gasolines and gasoils, having only ATZ crude oils in the feed, compares with the results of the base case, indicated in Example 1.

The feedstock used for this example is indicated hereunder (in kton/month):

BTZ FEEDSTOCKS (37°API, 0.13%S)11.0

-AMNA (37°API, 0.13%S)10.0

- AMNA FCC Cycle (37°API,0.13%S)1.0

-ATZ FEEDSTOCKS (33°API, 1.3%S)720.3

-IRANIAN LIGHT (33°API, 1.5%S)35.5

-URAL (32°API, 1.4%S)584.8

-CPC BLEND (44°API, 0.22%S)61.0

-GASOIL s/l (37°API, 2.0%S) -SYRIAN LIGHT (38°API, 0.74%S) -DPV ex LIV (24°API, 2.39%S) Total

26.0

7.7

5.3

731.0

The higher-efficiency refinery scheme is the same provided in Example 2.

The following tables respectively indicate the capacity available/percentage of use (Table 11) and the material balance ofthe products (Table 12)/

Table 11: Capacity/use

Kton/month; % use	Base case Ex.1	HER Ex. 4
CDU	731.0(100%)	731.0(100%)
VDU	327.0(78%)
Gasoil HDS 1	46.0(100%)	60.0(100%)
Kero HDS 1	16.8(100%)
HDS 2	144.0(100%)	348.1(100%)
HDS 3	72.0(100%)	75.6(100%)
EST		356.5 (100%)
Reforming 2	57.0(100%)	57.0(100%)
Reforming 3	75.0(100%)	80.5(100%)
Isomerization	41.1(100%)	63.0(100%)
Hydrogen	6.0	13.7
Alkylation	17.7(57%)
ETBE	3.6(57%)
FCC	159.0(60%)
Hydrocracker 1	115.2(100%)
Hydrocracker 2	115.2(100%)
Visbreaker	153.0(73)
BDA	48.0(100%)
Gasification	36.0 (100%)

Table 12: Material Balance

	Base case Ex.1	HER Ex 2	Variât. %
Products Kton/month	742.1	701.6
Syn gas	35.7
Fuel gas		18.4
LPG	17.9	51.1	185%
Gasoline	213.6	165.3	-23%
Virgin Naphtha FR	13.6
Kero	79.0	70.8	-10%
Gasoils	344.2	386.0	+12%
F.O. ATZ/Pitch	24.9	3.4
F.O. BTZ	7.3
Sulfur	5.9	6.6
Feedstock Kton/month	792	731.3
Mix crude oils	731	731.3
Atm. Residue	7.5
MTBE	8.1

CatFeed	45.4
C&P	49.9	29.7 '	-40%
Consumptions	44.3	25.4	-43%
Losses	5.7	4.3	-25%

The économie data indicated in Table 13 dérivé from these material balances.

Table 13: Economie resuit

M €/month	Base case Ex.1	HER Ex. 2
Yields from products	383.3	379.7
Syn gas	3.6
Fuel gas		9.1
LPG	8.8	18.4
Gasoline	118.9	92.0
Virgin Naphtha FR	6.6
Kero	42.5	38.1
Gasoils	191.9	215.3
F.O. ATZ/Pitch	8.3	0.2
F.O. BTZ	2.7
Sulfur	—
Cost crude oil and S/L cost	336.4	330.2
Raw material cost	28.1
Atm. residue	2.7
MTBE	5.2
CatFeed	20.2
Total crude oil MP	364.5	330.2
Operative gross margin	18.8	49.5
Δ Margin		+30.7
€/ ton		+42.0

From these results it can be seen that the used of lower quality crude oils allows the refining margins to be improved with respect to the products obtained, achieving a lower cost of the crude oil in the feed with respect to the base case. The advantage of the scheme, object of the présent invention, is destined to grow with an increase in the price differential between ATZ crude oils and BTZ crude oils. This factor becomes extremely important with the arrivai of non-conventional crude oil on the market, such as, 10 for example, extra heavy crude oils of the Orinoco basin or those obtainable from oil sands and oil shales.

Another important advantage of the invention using the EST technology in substitution of the subatmospheric section relates to the marked réduction in consumptions and losses (C&P), which leads to a lower quantity of CO₂emitted into the atmosphère. Table 14 indicates the total and spécifie consumptions and losses. These values are estimated assuming the value of 3.5 t CO₂/per ton of non-consumed 15 équivalent oil with respect to the base case.

Table 14: Réduction in CO2émission - Consumptions and losses

Examples	Ex. 1	Ex. 2	Ex. 3	Ex. 4
Products (kton/month)	742.1	702.5	707.8	701.6
Total C&P (kton/month)	49.9	28.5	23.2	29.7
Spécifie C&P ( ton/kton products)	67.2	40.6	32.8	42.3
Δ vs Base Case	-	-40%	-51%	-57%
Minor CChemitted ( ton/kton products)	-	93.1	120.4	87.1

In the case of Example 2, would be lower émissions of CO2equal to 68 kton/month.

iid

CONSEIL EM PROPRifTc ^,mus^LLEAGg_EE0API

Claims

1. A process for refining crude oil, comprising a séparation unit of the crude oil, consisting of at least one atmospheric distillation unit for separating the various fractions, units for the conversion of the heavy fractions obtained, units for improving the quality of some of the fractions obtained by actions on the chemical composition of their constituents, and units for the removal of undesired components, characterized in that the heaviest fraction, the atmospheric distillation residue, is sent to the conversion unit comprising at least one hydroconversion reactor in slurry phase or of the ebullated bed type, wherein hydrogen or a mixture of hydrogen and H2S is introduced in the presence of a suitable nanodispersed hydrogénation catalyst.

2. The process according to claim 1, wherein the nanodispersed hydrogénation catalyst is based on a sulfide of Mo and/or Fe and/or W and/or Cr and/or Ni and/or Co and mixtures thereof.

3. The process according to claim 1, wherein, when the hydroconversion reactor is of the ebullated bed type, a suitable heterogeneous, supported hydroconversion catalyst is also présent.

4. The process according to claim 1, wherein, when the hydroconversion reactor is in slurry phase, a suitable heterogeneous, supported hydroconversion co-catalyst is also présent.

5. The process according to claim 3 and 4, wherein the co-catalyst has particles of nanometric or micronic dimensions and is selected from cracking and/or denitrogenation catalysts.

6. The process according to claim 1 and 4, wherein the distillation residue is sent to one or more ebullated-bed hydroconversion reactors, the effluent stream from said reactor (s) being sent to a séparation step wherein the liquid fraction separated and containing the nanodispersed catalyst is recycled to said reactor(s).

7. The process according to claim 1, wherein the distillation residue is sent to at least one hydroconversion reactor with solid accumulation in slurry phase (such as, for example, that described in IT-MI2007A001044), wherein one or more stripping phases are included, with a suitable hot stripping gas so as to obtain the conversion products in vapour phase.

8. The process according to claim 1, wherein the distillation residue is sent to a hydroconversion reactor with solid accumulation in slurry phase of the bubbling tower type, in the presence of a catalyst based on molybdenum so as to obtain the conversion products in vapour phase directly in the reactor.

9. The process according to claim 1, wherein the distillation residue is sent to a hydroconversion reactor, where the products having a boiling point higher than 380°C, obtained by partial condensation of the gas phase at the outlet of said reactor, before or after the séparation of the non-converted asphaltene liquid, and possibly obtained by vacuum extraction of the same asphaltene liquid before to said hydroconversion i