CA1193217A - Hydroconversion of heavy crudes with high metal and asphaltene content in the presence of solube metallic compounds and water vapor - Google Patents

Abstract

A B S T R A C T
The present invention relates to a method of improvement of heavy crudes by hydro conversion at high temperatures in the presence of low cost metallic compounds, soluble in the heavy crude and water, as inhibitors of the formation of coke, followed by a deasphaltization phase for the recovery of the organometallics and its subsequent recirculation in the hydro conversion phase. The method is applicable particularly to batches with high metal and asphaltene contents, like a heavy crude or its vacuum residue.

Description

~3;~7 Introduction As it is known large deposits of heavy and extra heavy crudes exist on a worldwide level; these crudes have the inconvenience of having a high viscosity, a large quantity of metals and sulfur and a low yield in liquids, so that they are of little interest to the world markets. This least to the necessity of looking for new processing ways which will permit the improvement of these crudes, by obtaining the highest possible yield in liquids and a high quality, with the lowest possible cost. Numerous technologies exist at the present time which claim the production of synthetic crudes and of finished products by using one or sevexal phases of conversion or by the catalytic or thermal way. The principal inconvenience of the methods which include a thermal way is the forma-tion of coke; different methods have been used to avoid it, for example:
UOS. Patent 4,233,138 discloses a method in which a bisco-reduction of the batch is carried out in the presence of inorganic sulfides in order to eliminate the formation of coke.
U.S. Patent 3,131,142 engulfs a slurry hydro-cracking method wherein a compound soluble in the crude, selected from group IV and VIII, is added to the crude in quantities ranging between .1 and 1% by weight of metal.
~.S. Patent 2,091,831 engulfs a thermal cracking method carried out in the presence of organic acid salts soluble in the crude and selected from carboxylic acides with a metal from group VI and VIII.
U.S. Patent 4,092,238 discloses the hydro conversion of a residual batch obtained from the division of the crude into different effluents, and a recombination of the hydrocracked product with the different currents in order to produce a crude with low density and low sulfur.

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U.S. Patent 3,663,43~ describes a method for the hydro desulfurization of a heavy crude by way of two phases of hydro treatment, one first step carried out at high temperatures (400-~90F), together with hydroyen, with an increase of the hydrogenating activity along the bed, then a portion of the liquid effluent from the first bed passes across a second bed at 500-900F in the presence of a hydro-desulfurating catalyst.
U.S. Patent 3,779,897 describes a method for the hydro desulfurization (~IDS) and hydro denitrogenation of batches with boiling ranges between 400 and 1000F comprising several steps, one first step of hydro treatment, followed by a hydro cracking of the liquid effluents at pressures ranging between 1,200 and 1,500 psi.
U.S. Patent 3,161,585 claims a method of hydro refining which treats a crude with a finely dispersed catalyst, selected from the group of metals VB and VIB
of the Periodic Table. The concentration of the catalyst varies between .1 and 10% by weight (as elemental metal), in order to produce the hydro conversion.
More recently the U.S. Patents 4,134,825 and 4,192,735 of the firm Exxon Research Engineering Co.
have claimed a method of hydro conversion and hydrocrack-ing of heavy crudes by adding to said crude a soluble metallic compound in quantities of 10 to 950 ppm, cal-culated as elemental metal. The metal was selected from the following groups of the Periodic Table: IVB, VB, VIB, VIIIB and VIII, with molybdenum naphthenate being the preferred soluble metallic compound.
In this patent a particular combination of methods not included in the prior art, is claimed, which con-sists of treating the crude or vacuum residue in two steps of thermal hydro conversion at elevat~d tempera-tures in the presence of organo-metallic compounds and/or water, in order to reduce the formation of coke and the consumption of hydrogen, later the different frac~tions ~3~
~ 3 --are separated by distillation, and the light fractions pass into a hydro finish or the synthetic crude; the residue in turn, one part goes into recycling for its extinction and the other one ko a deasphaltation (see Figure 1). The deasphalted product is hydro treated or shipped as part of the uel oil to be used in the field.

De~ailed Description of the Method and Preferred ~xperimental Conditions Under the method, according to the present invention, the hydrocarbon, constituted by a heavy crude and/or its atmospheric or vacuum residue is pumped to the preheating zone (current 3) (see Figure 2), together with the recycled unconverted vacuum residue (10). The metallic compound soluble in the crude and/or gas is added to this current and the mixture is fed to the reaction zone together with the hydrogen, from the top or the bottom of the helicoidal reactor (e 1) (preferably from the top). The ratio metallic soluble compound to batch varies between 50 and

2~ 100 ppm by weight, preferably between 51 and 200 ppm, the hydrogen/batch ratio is variable between 100 and 2,000 Nm3/m3; it is possible to use the hydrogen which leaves th~ hydro treatment phase, prior to the purification (current 6), adding the necessary quantity of fresh hydrogen to maintain the hydrogen/batch relation and the partial hydrogen pressure at the entrance of the reactor. The metal in the liquid recycling current is from 400 to 15,000 ppm.
The linear speed of the liquid inside the helicoidal reactor is variable between .1 and 20 cm/second and that of the gas between .1 and 20 cm/second, heated in such a fashion that starting out from 230C there will be an average logarithmic ~ t of between 30 and 150C with a variable heat transfer between 350 and 10,000 Kcal/h m2.

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In this form the temperature of the liquid in ~his first phase the thermal hydro conversion reactor is gradually increased up to a maximum ranging between 420 and 540C, the preferred value being fixed between 440 and 500C.
The claimed operating pressure varies between 20 and 250 atmospheres, with the preferred value beiny fixed at 50 to 150 atmospheres.
The preferred linear speed in the second reactor (R-2) (soaker) varies between .3 times 10 2 and .3 times 10 1 cm/second, both in ascending current. The operating temperature varies between 420 and 480C preferably 430 and 460C substantially less than in the helicoidal reactor and without bringing in outside heat. The pres-sure is substantially the same as in the helicoidal reactor (20 to 200 atmospheres).
The products of this phase are separated by means of a distillation (current ~): a) the residual fraction (500C ~ is sent partly to the deasphaltation (current 11);
b) the other part is recycled to the first or second phase of hydro conversion (current 10).
The deasphaltation is carried out with C5 at 100C-170C and from 14 to 50 atmospheres, preferably at 120-150C
and 20-30 atmospheres of pressure. The asphaltenes are withdrawn in the presence of an aromatic gas oil and sent to combustion to generate energy or to produce hydrogen.
Both phases are not cla:imed specifically. The burned asphaltene generates ashes which contain primarily vanadium, nickel, iron and solium, which are treated in a digestion in sulfuric acid and the molybdenum is recovered in various stages which are not claimed specifically here.
Then the deasphalted material i5 separa~ed by distillation into cuts which are hydro-finished later or the DAO is treated completely in one or several phases of hydro treatment. The gasoline and the Diesel oil are treated by using the conventional fixed bed technology with the descending flow of reaction in the presence of hydrogenation catalysts, hydro sulfuriza-tion an hydrodenitrogenation. These conventional methods are not claimed here specifically.
The vacuum gas oil and/or the DAO are treated in an unconventional system of hydro treatment. This phase of hydrotreatment may be constituted by one or more catalyst beds which have the characteristics claimed in table 1.
These catalysts are prepared by successive impregna-tions of the metals of group VIB and VIII in macroporous supports containing more than 40~ of pore radii larger than lOOA. The soluble salt of the metal of group VIB is placed in contact with the support during a time varying between 0 and 24 hours, preferably from 1 to 5 hours; the impregnated material is dried at a temperature varying between 80 and 1209C and calcinated at 400-600C
(preferably 450-550). This calcinated catalyst is then put in contact with a solution of one or more metals of group VIII during a time varying between .2 and 5 hours, preferably from .5 to 3 hours, dried again at 80-120C, activated at a temperature varying between 400 and 600C (preferably 450-550C); then it is treated with water vapor at 600C and finally pre-s-llfurized in the presence of carbon disulfide and hydrogen at a temperature varying between 230 and 350C.
In the case of the use of two or more catalytic beds, they may be arranged in the same reactor or in separate reactors in series and in such a form that a homogen-eous distribution of the deposition of metals will be obtained. The hydrocarbon and the hydrogen follow a descending path along the catalytic bed through the first and second catalytic bed.
The operating pressure varies bPtween 20 and 200 atmospheres, preferably 50~150 atmospheres, the ~3~7 temperature varies between 350 and 440C and preferably 370-430C. The hydrogen:hydrocarbon ratio varies between 100 and 2~000 ~m3/m3, preferably between 100 and 1,500 Mn3/m3. In both the first and in the second catalytic bed, the hydrocarbon and the hydrogen react in such a manner that the ratio final temperature to initial temperature is less than 1~2 in C. The linear speed of the liquid in the reactor varies between .4 and .3 m/hour, preferably between .5 and 20 m/hour. The reaction is accomplished there in such a manner that the relation between the inlet temperature and the one at the outlet and the linear speed of the liquid in the reactor will be essentially the same as the ones specified for the first bed. The present inven~
tion is not limited to the use of one or two reactors, one or two catalysts, but to an arrangement of chemical reaction consisting of one or more catalysts and one or more reactorsl according to the final specifications of the products and the required opera~ing time. The total product, that is to say the recombination of the different effluents can be sold as high quality synthetic crude.
It has been found that under these particula~ con-ditionc and only under these conditions, an adequate conversion is obtained into products of high quality with a minimum formation of gases and cok~, and with maximum yield in volume of liquids, all of which is obtained with adequate operability and a minimum energy consumption.
E~amples: Below the examples are described for the purpose of illustration without thereby being limitative of the claims of the invention.

Example N 1 This example represents the typical tests which demonstrate the suppressive effect of the soluble metallic compounds in the formation of coke~
This related to a complete Morichal Crude in an autoclave with a capacity of 2.5 liters, with and without the presence of the soluble metallic com-pounds. The experimental conditions were: Tempera-ture = 420C, Pressure = lB00 psi, and time of sojourn =
~ 60 minutes. As can be appreciated in Fig. 3, the coke and gas are reduced considerably by using the compound molybdenum acetyl acetonate as soluble metallic compound.
Example N 2 ~ The purpose of this example is to demonstrate the 15 efficiency of the soluble metallic compounds in the heavy crude for reducing the heavy fraction of the crude 500C~.
It can be seen from Table N6 that the product obtained when treating a whole Morichal Crude at 420C
in the presence at 265 ppm of molybdenum (added as molybdenum acetyl-acetonate), reduces the 500C~ by - 85%.
Example N 3 In this example a whole Morichal Crude was treated 25 (see characteristics in Table 2) in a heat phase (helicoidal reactor) followed then by a hydro demetal-lization and hydro desulfuration, carrying out deasphalta-tions of the products obtained in each phase. The experimental conditions are compiled in Table N3, and the ctatlysts used in Table No. 4.
As can be observed in Table N2, under these con-ditions a product of good quality is obtained in each phase, which is much more improved when the deasphaltation is used.

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The hydrogen:hydrocaxbon ratio is 1000:1 ~n3/m3, and the linear speed in the reactor for liquid and gas is .1 cm/second.
Example N4 The operation was carried out in accordance with the description in Figs. N 1 and 2. ~ test conducted in which the hydro conversion reactor was operated by using the two phases, helicoidal reactor and soaker reactor; the batch was a Cerro Negro crude at 8 API, see properties in Table N 8. Material ~rom a preceding treatment was added under the same conditions, which was distilled to obtain the 500C~ residue. ~his batch was added to 9~ by weight in the principal crude current; moreover, 100 ppm additional molybdenum com-pound were added to the one which carries the recycling (2500 ppm). The compound was ~ed into the helicoidal reactor, which was operated at a temperature of ~90C
with 15 minutes of time of sojourn and a pressure of 103 kg/cm2. The product from this phase of hydro con-version is fed to a second conversion phase in a soaker reactor operating in ascending flow with a gas and liquid speed of .015 cm/second, a temperature of 440C, an operating pressure of 103 kg/cm2 and a sojourn time of .80 hours. The hydrogen:hydrocarbon ratio is main-tained at 1000~1 Nm /m .
The hydro con~ersion product is distilled to obtain the naphtha, DOL and GOV. Part of the heavy product (vacuum residue 500C+~ is mixed with gas oil and treated in a continuous deasphaltation unit with isopenthane operating at 34.5 kg/cm2 and 120C with a solvent;batch ratio of ~:1. The produced asphaltene is burned to produce the corr~sponding ashes. They are treated chemically to recover an amoniacal molybdenum solution ~rom which the acetyl acetonate compound is prepared.

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The deasphalted material may be treated together with the GOV in a hydro treatment unit or be shipped ~o the field to produce energy.
The Gasoline and the Diesel Oil were treated in a fixed bed unit using a Shell-324 catalyst to complete the removal of nitrogen sulfur and to estahlish the product. The vacuum and/or the deasphalted Gas oil were treated using a combined bed of catalysts described in example No. 3. The operating conditions were: temperature: 390C, pressure: 103 kg/cm2, time of sojourn: 1 hour. The product is described in Table 8.
The synthetic crude obtained with the use of energy for the field has the properties described in Table of Figure 1. If hydro-treated DAO is included, the properties described in Table N 9 are obtained.

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HDMAND HYDRO FINISHED CATALYST

PROPERTIES TYPE A TYPE B
MoO3% (by weight) 0-20 8-15 W 03 ~ 0-20 5-10 NiO %(by weight) 0-8 2-6 CoO ~(by weight) 0-8 2-6 SiO~ complement complement particle size (inch) 1/32-1/4 1/16-1/6 Area Bet (m2/g) 50-3Q0 150-300 pore volume (cc/g) 0.6-1.4 Q.8-1.2 pore diameter (A) 80-400 110-200 apparent density 0.6-1.5 0.8-1.4 real density (g/cc) 2.7 4-6.4 Bed density (g/cc) 0-4-0-9 0.54-0.8 Resistance of the pellet (kg/pellet) 2-6 2.4-5 Distribution of pores (~Vp) 150 -300 ~ O - 40 0 - 20 10 A O - 40 15 ~ 35 TYPE A clai.med TYPE B claimed preferably 3~

CHARACTERISTICS OF THE PRODUCTS

. . _ , Charac~eristics ~orichal Hydroconversion Hydrw on~ersion Final Crude PhasePhase Deasphalted + Product Hy~ro Treatment Gravity API 11,8 15,5 18,7 21,3 Sulfur (~ by weight) 2,85 1,88 0,74 0,43 Vandadium (ppm) 331 _ 53,8 18,7 Nic~kel (ppm)89,1 _ 41,9 Nitrogen (ppm)5.830 4.682 _ Conradson Carbon (% by weight)12,0 9,18 6,79 4,00 Asphaltene (% by weight) 9,0 6,17 3,21 Viscosity Kin (CST~
140 F 600 77,22 37,3 19,6 100F .533 197,0 79,3 Water(% by weight) 0,1 _ _ Brcme Number 12 14 _ Carbon (% b~
weight) 84,3 84,5 83,7 86,86 ~ydrogen (~ by weight) 10,5 11,14 11, 24 11,97 Consumption of H
(cubic feet/bb~ 500 550 Distillation TBP

375F _ 6,18 3~ 78 4 375 - 650 10,8 20,56 28,33 40 650 - 950 30,7 30,00 28,78 42 ~50+ 5~,5 43,26 39,11 14 ~ ~3~

TABLE N~ 3 CONDITIONS OF REACTION
_ Operating Conditions Hydroconversion Phase Hydro Treatment Phase Catalyst(100 ppm Additive) AMN-5-32 Morichal CrudeMorichal Crude HC Product Pressure, Psi 1500 150G
Temperature of the HCT* Reactor (C)480 Temperature of the Catalytic Bed (C) 400 Flow of the batch (cc/hour) 200 300 Flow of the ~ydrogen liters/minute 2 5 Ratio H2:batch -1600 1000 **Spacial Speed2(h ) 2.5 Notes:
* ~CT = Thermal Hydro Conversion ** Spacial Global Speed = .71 h 1 ~3~

CHARACTERISTICS OF THE CATALYSTS

PROPERTIES (HT PHASE) (HC PHASE) % MoO3 10.2 8.10 % NiO -- 1.73 % CoO 2.3 --Support A123 A123 Particle Size (Inch)1/32 1/32 BET Area (m gram) 271 177 Pore volume (cc/gram).74 .67 Pore Diameter (A) 124 151 Apparent Density (grams/cc) .87 1~10 Real Density (grams/cc) 3.26 4.77 Bed density " .68 .58 Resistance of pellet(kg/pell.) fragile fragile Bed resistance (kg/cm2) 11.60 Pore distribution(% Vp) Diameter (A) - 30 8.0 14.41 - 60 12~0 14.~1 - 90 7.0 ~0.81 - 150 21.0 19.82 150 - 300 38.0 28.82 300 - 103 1~.0 5.41 103 1.0 6.31 3~7 CHARACTERIZATION OF THE DISTILLATES

DISTRIBUTION OF SULFUR (% BY WEIGHT) IN EACH FRACTION

PRODUCT PRODUCT
FRACTION (*F) (~C) (HT) 375 .16 --375 - 650 .70 05 650 - 950 1.39 .42 950 2~71 1.10 DISTRIBUTION OF VANADIUM (ppm) FRACTION (*F) PRODUCT PRODUCT
(HC) (HT) 950 979.08 + 10.4% 118 ANALYSIS OF THE NUMBER OF XETANES FOR THE FRACTION

PRODUCT (HC) = 40.0 PRODUCT (HT) = 37.5 ~3~

EFFECT OF THE MO02 (AA)2 ON THE YIELD IN DISTILLATES

I
S~MPLE C4-375F 375-650F650-930F 930F-930F~
_ ~V~ (%V)(%V) (%V) (~V) CONTROL
MORICHAL
CRUDE 0.0 14.025.5 39.560.5 _ _ _ PRODUCT
AT 420~C 7.2 28.222.2 57.623.0 , PRODUCT

265 ppm Mo 8.0 51.129.2 88.310.0 -AUTOCLAVE, P = 1800 psi, 1 hour and OR~ANO MET~LLIC ADDITIVE
WITHOUT PRIOR TREATMENT

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CONDITIONS OF REACTION
CONVERSION
Feeding to the reactor coil + soaker (grams/min) 0.87 Molybdenum ~Ac.(Ac)) (grams/min.) 1.7 x 10 4 Recycling (grams/minute) 0.086 Pressure kg/cm2 103 Temperature C 490/440 Sojourn time coil soaker (hours) 0.25/0.64 DEASPHALTATION
Temperature C 120C
Pressure kg/cm2 34.5 Solvent isopenthane Solvent/batch (vol/vol) 4:1 HYDRO TREATMENT
Catalyst Shell 324 Temperature 390C
Pressure 103 kg/cm2 Sojourn time (hours) 1 hour ~3~

EXP~lPLR 4 PROPERTIES BATCH ¦ PRODUCT BATCH ¦ PRODUCT
__ _ _ ~ _ CRUDE API 8 RV + GOL
PHASE HYDRO CONVERSION DEASPHALTATION
. __ Density 15C 1,013 0,904 0,97 0,95 C ~ by weight 84,0 84,55 85,0 84,3 H ................. 10,1 10,65 10,9 11,3 S ., 3,4 2,2 2,4 2,05 N " 0,6 0,4 13,4 __ Asphaltenes % by weight 10,0 2~1 __ 1%
Conradson Carbon 14 5,68 16 12,1 Distil:lation 10 % V 280 140 250 240 20 % V 370 220 290 285 30 % V 400 280 310 305 ~0 % V __ 330 350 345 50 % V __ 358 __ __ 60 % V __ 400 __ __ ~0 % V __ 455 __ __ 80 % V __ 496 __ __ Yield 500/58 500/81,5 500/60 500/58,5 _ _ _ . _ Yield %
Liquid 100 95,0 14,$5 12,52 S~lsip~altenes) __ __ __ 2,03 Gase~ __ 6,5 _~ __ _ ~32~

~ 18 -TABLE N 8 (CONTINUATION) I ~ r~
PROPERTIES I BATCH . PRODUCT BATCH PRODUCT
GOV GOV ~ DAO
_ __ ~_ ~ .~_ HYDROTREATMENT
____ ~
Density 15C 0,940 0,922 0,96 0,938 C % by weight 85,20 84,8 ¦ 84,8 84,5 E ~' 11,50 11,7 ¦ 11,45 11,8 S " 2,7 1 0,5 1 2,5 0,63 N " 0,4 1 0,2 1 0,45 0,31 Asphaltenes % by weight __ __ 1 __ Conradson Carbon % by weight 0,38 0,03 9 _ _ Distillation IBPC 332 ¦ 80 175 50 10 ~ V 352 ! 200 1 280 200 20 % V 380 355 1 350 300 30 % V 402 380 390 355 40 % V 420 400 405 387 50 % V 433 420 430 408 60 % V 456 433 455 432 70 ~ V 470 451 480 460 80 % V 490 470 __ 490 PIE/Yield ~00/93,5 500/100 500/77 500/85 _ . _ _ _ I
Yield % by weight Liquids 36,66 35,93 49,10 48,148 Solids _._ __ __ __ Gas __ 0,733 __ __ , . _ __

Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A thermal hydroconversion process for a hydrocarbon feedstock containing asphaltene and metals which comprises the steps of (a) combining said feedstock with water, fresh molybdenum acetylacetonate in an amount of about 50 to about 600 parts per million by weight, and a recycle stream containing molybdenum in an amount of about 400 to about 15,000 parts per million by weight, and pre-heating the resulting admixture to a temperature of at least about 230°C.;
(b) introducing hydrogen into the pre-heated admixture and subjecting the resulting mixture to thermal hydroconversion at a maximum temperature of about 420°C. to about 540°C. and a pressure of about 20 to about 250 atmospheres for a time period sufficient to effect hydroconversion of the feedstock and produce a hydroconverted mixture;
(c) fractionating the hydroconverted mixture to produce at least one vapor phase fraction and a residue fraction containing molybdenum; and (d) recycling at least a portion of the residue fraction to step (a).

2. The process in accordance with claim 1 wherein the thermal hydroconversion is carried out at a hydrogen-to-hydrocarbon feedstock volumetric ratio of about 100 to about 2,000, the volume of hydrogen taken at standard conditions, and in two stages, with - Page one of Claims -the first stage being at about 440°C. to about 500°C. and at a pressure of about 50 to about 150 atmospheres and the second stage being at a temperature of about 430°C. to about 460°C. and at a pressure of about 20 to about 200 atmospheres.

3. The process in accordance with claim 2 wherein the first stage is carried out in a helicoidal reactor heating the incoming pre-heated admixture at a variable heat transfer rate beginning at about 350 Kcal/hour/m2 and increasing to about 10,000 Kcal/hour/m2, and wherein the second stage is carried out in a soaker reactor.

4. The process in accordance with claim 1 wherein that portion of the residue fraction not recycled to step (a) is subjected to deasphaltation.

5. The process in accordance with claim 3 wherein the deasphaltation is carried out at a temperature in the range of about 100°C. to about 170°C. and at a pressure in the range of about 14 to about 50 atmospheres.

6. The process in accordance with claim 4 wherein the deasphalted portion of the residue fraction is hydrotreated in a catalytic bed at a temperature of about 350°C. to about 440°C., at a pressure of about 20 to about 200 atmospheres, and at a hydrogen-to-hydrocarbon volumetric ratio of about 100 to about 2,000, the volume of hydrogen taken at standard conditions.

- Page two of Claims -

7. The process in accordance with claim 4 wherein the deasphalted portion of the residue fraction is hydrotreated in a catalytic bed at a temperature of about 370°C. to about 430°C., at a pressure of about 50 to about 150 atmospheres, and at a hydrogen-to-hydrocarbon volumetric ratio of about 100 to about 1,500, the volume of hydrogen taken at standard conditions.

- Page three of Claims -