Procedure for preparation of improved solid hydrogen transfer agents for processing heavy and extra-heavy crude oils and residues, and resulting product

Abstract

The present invention relates to the process for preparing improved solid hydrogen transfer agents obtained from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene, which exhibit activity as hydrogen transfer agents in any chemical reduction reaction involving the breaking of double bonds and in treatment, hydrotreatment and hydrodisintegration reactions of heavy and extra-heavy crude oils and of cuts and currents derived therefrom. These improved solid hydrogen transfer agents can be supported and not supported on metal oxides such as boehmite, alumina, silica, titania, kaolin and/or mixture thereof, in the presence of reducing agents such as hydrogen, methane, or natural gas. In addition, the application of these improved solid hydrogen transfer agents obtained from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene, it allows to improve properties of the crudes such as viscosity, decrease in the formation of coke, increase in the yield of distillates and in API gravity. These hydrogen transfer agents, being solid, can be reused and recovered from the reaction medium; they also have a thermal stability such that it can carry out reactions at temperatures up to 450 C.

Claims

1. A process for preparing improved solid hydrogen transfer agents for the processing of heavy or extra-heavy crudes or residues, comprising: a) preparing raw materials by grinding one of AlO (OH) (Boehmite), SiO.sub.2, Al.sub.2O.sub.3, and kaolin, or a mixture thereof, with an organic macromolecule featuring fused aromatic rings, said organic macromolecule having a melting or decomposition point above 450 C. when supported or extruded, while sieving the raw materials through a 165 mesh (0.089 mm), resulting in a physical mixture; b) adding distilled water to the physical mixture and mixing until the mixed distilled water and physical mixture forms a paste, and subsequently peptizing the paste by adding an aqueous solution of nitric acid of 5% by volume to form a gel; c) mixing the gel with a naphthalene polymer that may be supported on a metal oxide, resulting in a resin material with adequate properties for extruding; d) extruding the resin by a mechanical extrusion system at a constant speed, and receiving the extrudates in metal trays; e) drying the extrudates for a time period of about 12 hours to about 24 hours at room temperature, resulting in solid hydrogen transfer agents; f) preparing the solid hydrogen transfer agents for activation by cutting the transfer agents to a length in a range of about 0.5 cm to about 1.2 cm and leaving the transfer agents in an oven at a temperature of about 90 C. to about 120 C. for a time period of about 12 hours to about 24 hours; and g) loading the material obtained in part f) into a continuous flow reactor where a hydrogen flow of about 100 ml/min to about 150 ml/min, a pressure of about 40 kg/cm2 to about 70 kg/cm2, and a temperature between about 100 C. and about 500 C. is passed for a time of about 10 hours to about 24 hours.

2. The process according to claim 1, further comprising: h) contacting the solid hydrogen transfer agent with a heavy, extra-heavy crude or residue of about 9 API to about 12 API and viscosity of about 5968 cSt, measured at 37.8 C., at a temperature of about 350 C. to about 450 C., at a pressure of about 50 kg/cm.sup.2 to about 100 kg/cm.sup.2 in hydrogen transfer reactions, where the hydrogen transfer reactions are carried out in the presence of a reducing agent selected from a group consisting of hydrogen, methane, and natural gas; and i) obtaining heavy or extra-heavy crudes or residues with an increase in API gravity from 3 to 6 units, a decrease in viscosity up to about 100 cSt determined at 37.8 C. and an increase in the yield of distillates, naptha and intermediate distillates, determined by TBP (True Boiling Point), wherein the solid hydrogen transfer agent has a specific area between about 100 m.sup.2/g to about 300 m.sup.2/g, a pore volume between about 0.15 cm.sup.3/g and about 0.20 cm.sup.3/g and a pore diameter of about 15 to about 19 , and an average molecular weight between about 300 g/mol and about 1000 g/mol with a thermal stability at about 800 C. between about 60% and about 90% by weight of the original material and chemical stability at a temperature up to about 450 C.

3. The process according to claim 1, wherein the raw materials comprise Boehmite mixed with a polymer with units containing the structure of naphthalene.

4. An improved solid hydrogen transfer agent, obtained by a process comprising: a) preparing raw materials by grinding one of AlO (OH) (Boehmite), SiO.sub.2, Al.sub.2O.sub.3, and kaolin, or a mixture thereof, with an organic macromolecule featuring fused aromatic rings, said organic macromolecule having a melting or decomposition point about 450 C. when supported or extruded, while sieving the raw materials through a 165 mesh (0.089 mm), resulting in a physical mixture; b) adding distilled water to the physical mixture and mixing until the mixed distilled water and physical mixture forms a paste, and subsequently peptizing the paste by adding an aqueous solution of nitric acid of 5% by volume to form a gel; c) mixing the gel with a naphthalene polymer that may be supported on a metal oxide, resulting in a resin material with adequate properties for extruding; d) extruding the resin by a mechanical extrusion system at a constant speed, and receiving the extrudates in metal trays; e) drying the extrudates for a time period of about 12 hours to about 24 hours at room temperature, resulting in solid hydrogen transfer agents; f) preparing the solid hydrogen transfer agents for activation by cutting the transfer agents to a length in a range of about 0.5 cm to about 1.2 cm and leaving the transfer agents in an oven at a temperature of about 90 C. to about 120 C. for a time period of about 12 hours to about 24 hours; and g) loading the material obtained in part f) into a continuous flow reactor where a hydrogen flow of about 100 ml/min to about 150 ml/min, a pressure of about 40 kg/cm2 to about 70 kg/cm2, and a temperature between about 100 C. and about 500 C. is passed for a time of about 10 hours to about 24 hours, wherein the solid hydrogen transfer agent has a specific area between about 100 m.sup.2/g to about 300 m.sup.2/g, a pore volume between about 0.15 cm.sup.3/g and about 0.20 cm.sup.3/g and a pore diameter of about 15 to about 19 , and an average molecular weight between about 300 g/mol and about 1000 g/mol with a thermal stability at about 800 C. between about 60% and about 90% by weight of the original material and chemical stability at a temperature up to about 450 C.

5. The improved solid hydrogen transfer agent of claim 4, wherein the raw materials comprise Boehmite mixed with a polymer with units containing the structure of naphthalene.

6. A method for preparing an improved solid hydrogen transfer agent and upgrading of heavy or extra-heavy crudes or residua, comprising: obtaining the solid hydrogen transfer agent from a combination comprising one organic polymer and an inorganic compound, wherein the organic polymer contains structural units based on the structure of one of naphthalene, phenanthrene, or anthracene, and has a melting or decomposition point above 450 C. when supported or extruded; wherein the inorganic compound is a metal oxide; and wherein the upgrading of heavy or extra-heavy crude oil or residua is carried out by hydrotreatment.

7. The method of claim 6, wherein the organic polymer is physically mixed with the inorganic compound.

8. The method of claim 6, wherein the inorganic compound is selected from a group consisting of AlO(OH) (Boehmite), SiO.sub.2, Al.sub.2O.sub.3, and kaolin.

9. The method of claim 6, wherein the organic polymer has a molecular weight average between about 600 g/mol and about 1200 g/mol.

10. The method of claim 6, wherein the improved solid hydrogen transfer agent has a specific area between about 100 m.sup.2/g to about 300 m.sup.2/ g, a pore volume between about 0.1 cm.sup.3/g and about 0.60 cm.sup.3/g and a pore diameter of about 15 to about 20 , with a thermal stability and a chemical stability at temperatures up to about 450 C.

11. The method of claim 6, wherein the solid hydrogen transfer agent is activated in a continuous flow reactor featuring a hydrogen flow of about 100 ml/min to about 500 ml/min, a pressure of about 40 kg/cm.sup.2 to about 70 kg/cm.sup.2, and a temperature between about 100 C. and about 500 C. is passed for a time of about 10 hours to about 24 hours.

12. The method of claim 6, wherein the upgrading is carried out by hydrotreatment in a fixed bed reactor under operating conditions comprising a temperature of about 350 C. to about 450 C., and a pressure of about 50 kg/cm.sup.2 to about 100 kg/cm.sup.2.

13. The method of claim 6, wherein an upgrading of heavy or extra-heavy crudes or residues comprises an increase in API gravity of about 3 units to about 6 units, a decrease in viscosity up to about 100 cSt determined at 37.8 C., and an increase in distillate yield as determined by True Boiling Point (TBP) naphtha and intermediate distillates between about 10% to about 20% by volume.

14. The method of claim 6, wherein the solid hydrogen transfer agent maintains constant activity in the hydrotreatment of a heavy crude by showing a constant viscosity in the product for a time period of at least 20 days.

Description

BRIEF DESCRIPTION OF THE INVENTION DRAWINGS

(1) With the purpose of better understanding the procedure for the preparation of the improved solid hydrogen transfer agents derived from polymers having in their structure naphthalene, phenanthrene or anthracene units, object of the present invention, we will refer to the accompanying figures, without limiting the scope of the invention:

(2) In FIG. 1 we show a Thermogravimetric Analysis (TGA) of an improved solid hydrogen transfer agent in nitrogen atmosphere and in air atmosphere.

(3) In FIG. 2 we show the kinematic viscosity (cSt) results of samples of upgraded crude oils obtained in a pilot plant where the reactor was packed with an improved solid hydrogen transfer agent having in its structure naphthalene units, using a 10.7 API crude oil as feedstock and hydrogen as a reducing agent.

(4) In FIG. 3 we show the TBP distillation results of samples of upgraded crude oils obtained in a pilot plant where the reactor was packed with an improved solid hydrogen transfer agent having in its structure naphthalene units, using a 10.7 API crude oil as feedstock and hydrogen as a reducing agent.

DETAILED DESCRIPTION OF THE INVENTION

Description

(5) The present invention relates to the process for the preparation of solid hydrogen transfer agents from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene (1), which may be supported on metal oxides such as alumina, silica, titania or kaolin and/or mixture thereof, for use in any hydrogenation reaction involving the saturation of compounds containing double bonds in their chemical structure and in the improvement of heavy and extra heavy crudes, in thermal treatment and hydrotreating reactions of heavy and extra-heavy crudes, residua and cuts and streams derived from it. These solid hydrogen transfer agents improve physical properties of crude oils such as API gravity, viscosity, increased distillate yield and prevent coke formation.

(6) The solid hydrogen transfer agents, another of the objects of the present invention are prepared from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene; these can be anchored or in physical mixture with metallic oxides such as alumina, silica, titania or kaolin, or a mixture of them, their application extends in any chemical reaction involving a reduction and for the thermal treatment, hydrotreating or hydrocracking of heavy hydrocarbons, such as heavy or extra-heavy crudes and residues from the distillation of oil and from cuts and currents derived therefrom. These hydrogen transfer agents, because they are solids, can be recovered from the reaction medium for later reuse, and have a thermal stability that allows to carry out reactions at temperatures up to 450 C. These solid hydrogen transfer agents improve properties of heavy crudes such as API gravity, viscosity, increase in distillate yield and decrease coke formation during thermal treatment, hydrotreatment and/or thermal cracking reactions.

(7) The improved solid hydrogen transfer agents obtained from a polymer with units containing the structure of naphthalene, anthracene or phenanthrene, object of the present invention is an alternative to perform any chemical reaction involving the reduction of double bonds. The reduction reactions are limited by the availability of hydrogen that must be transferred to the liquid before starting the hydrogenation reaction, and by the hydrogen partial pressure; the improved solid hydrogen transfer agents of this invention provide an additional amount of hydrogen atoms to carry out hydrogenation reactions, since the naphthalene units present in their composition present a hydrogenation-dehydrogenation equilibrium.

(8) The present invention relates to the process for the preparation of improved solid hydrogen transfer agents of the naphthalene type, but more particularly improved solid hydrogen transfer agents obtained from a polymer with units containing the structure of naphthalene and an inert support, as described in the chemical structure (1). This polymer with units containing the structure of naphthalene, presents activity as a hydrogen transfer agent any reduction reaction of chemical double bonds between two carbon atoms, as in the case of the asphaltenes present in high concentration in the heavy and extra-heavy crudes; the solid hydrogen transfer agents, obtained from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene, have a melting and/or decomposition point above 450 C., when they are supported or extruded, it is possible to improve their textural properties such as hardness and surface area by mixing with clay materials and/or metal oxides such as alumina, silica, titania or kaolin. In addition, the present invention describes the use of these improved solid hydrogen transfer agents in any chemical reaction involving reduction of chemical functional groups, in the presence of a reducing gas such as hydrogen, and in the thermal treatment of heavy and extra-heavy crudes and products or fractions obtained from them.

(9) A feature of this invention is that the process for preparing the improved solid hydrogen transfer agents is carried out in two stages: the first consists of the physical mixture of a polymer with units containing the structure of naphthalene with an inert support such as boehmite, kaolin and silica and/or a mixture of them and the second is to activate the material in the form of extrudate for use as a hydrogen donor.

(10) Furthermore, the present invention has as a characteristic that the improved solid hydrogen transfer agents when subjected to a reducing environment such as hydrogen, methane or any hydrocarbon stream in the gas phase, as in the case of natural gas, reduces the naphthalene rings present in the polymer used as a raw material in the preparation of the hydrogen donor, to partially hydrogenated rings with a structure similar to tetralin under the conditions of appropriate pressure and temperature.

(11) Additionally, a feature of the present invention is that since the hydrogen transfer agents of the present invention are solids, they can be recovered for later use in a practical manner, unlike liquid hydrogen transfer agents such as tetralin or decalin.

(12) Therefore, the present invention relates to the process of preparing improved solid hydrogen transfer agents, which present activity as hydrogen donors for reduction reactions of unsaturated compounds in general and hydrocracking of high molecular weight molecules in molecules of lower molecular weight in a fixed bed inside a batch or continuous flow reactor that allows to develop the reduction and hydroprocessing reactions and wherein the properties of the solid hydrogen transfer agents, prepared from polymers with units containing the naphthalene structure, have a melting and/or decomposition point above 450 C., present chemical stability of the structure (functional groups), have the possibility of improving textural properties by means of mixtures with clay materials when supported and not supported by metallic oxides such as alumina silica, titania or kaolin and can be manufactured from commercial and economic raw materials with easily scalable preparation processes. In addition, the present invention describes the application of improved solid hydrogen transfer agents prepared from a polymer with units containing the structure of naphthalene, phenanthrene or anthracene in thermal hydrotreating reactions of heavy and extra-heavy crude oil and of cuts and currents derived therefrom, in the presence of reducing agents such as hydrogen.

(13) The process for preparing improved solid hydrogen transfer agents with units containing the structure of naphthalene, phenanthrene or anthracene, object of the present invention considers the following steps: a) Preparation of the raw materials: pulverize in a porcelain mortar AlO (OH) also known as Boehmite, SiO.sub.2, or Al.sub.2O.sub.3 or kaolin, selecting the Boehmite and a polymer with units containing the structure of naphthalene, phenanthrene or anthracene, preferably naphthalene, sieved raw materials through a 165 mesh 165 (0.089 mm); b) Preparation of the physical mixture: 60 to 100 g of grinded and sieved Boehmite are added from 20 to 100 ml of distilled water and mixed to form a paste, subsequently, it is peptized by adding 10-50 ml of an aqueous solution of nitric acid at 5% by volume to form a gel; c) Mixed with the gel obtained, add 10 to 100 g of a polymer with units containing the naphthalene structure, until a material with adequate properties for extrusion is obtained; d) Extrusion of the physical mixture AlO (OH)-polymer resin. The paste obtained in section b), is placed in a mechanical extrusion system at a constant speed, the extrudates are received in metal trays e) Drying. The extrudates are dried 12 hours at room temperature; and, f). Preparation of solid hydrogen transfer agents for activation. The material is cut to the desired length and left in an oven at 90 C. for 12 hours.

(14) The improved solid hydrogen transfer agent obtained in the present invention possesses the following technical characteristics: a specific area between 100-300 m.sup.2/g, pore volume between 0.15 and 0.20 cm.sup.3/g and pore diameter 15 to 19 , average molecular weight between 300 and 1000 g/mol with thermal stability at 800 C. between 60 and 90% by weight of the original material and chemical stability at temperatures above the temperatures (450 C.) of hydrogen transfer reaction.

(15) The process for improving heavy, extra-heavy crudes or residues in which the improved solid hydrogen transfer agent obtained in the present invention is used, comprises: a) contacting the improved solid hydrogen transfer agent with a heavy, extra heavy crude or residue load of 9 to 12 API and viscosity of 5.968 cSt measured at 37.8 C. at a temperature of 350 to 450 C. at a pressure of 50 to 100 Kg/cm.sup.2 wherein the hydrogen transfer reactions are carried out in the presence of a reducing agent, such as hydrogen, methane or natural gas; b) obtain heavy or extra-heavy crudes or residues with an increase in API gravity from 3 to 6 units, a decrease in viscosity up to 100 cSt determined at 37.8 C. and an increase in the yield of distillates determined by TBP (True Boiling Point) naphtha and intermediate distillates, mainly between 10-20% by volume.

EXAMPLES

(16) Below are presented examples related to the preparation process of improved solid hydrogen transfer agents with units containing the structure of naphthalene, phenanthrene or anthracene, object of the present invention and described above, without these examples limit the scope of the present invention.

Example 1. Preparation of the Improved Heterogeneous Hydrogen Donor

(17) This example shows the procedure for the preparation of the improved heterogeneous hydrogen donor (1).

(18) In a porcelain mortar, AlO (OH), also known as Boehmite, and a polymer with units containing the naphthalene structure of molecular weight between 500 and 1000 g/mol are grinded and then sieved through 165 mesh (0.089 mm). At 60 g grinded and sieved Boehmite, 20 to 100 ml of distilled water are added and mixed until a paste is formed, then 10-50 ml of an aqueous solution of 5% by volume nitric acid are added to form a gel. To this mixture is added stepwise from 10 to 100 g of a polymer with units containing the naphthalene structure, until a material with suitable properties for extruding is obtained.

(19) Extrusion of the physical mixture AlO (OH)Polymeric resin. The paste obtained in section a) is placed in a mechanical extrusion system at a constant speed, the extrudates are received in metal trays and left to dry for 12 hours at room temperature. The material is cut to the desired length and left in an oven at 90 C./12 hours.

Example 2. Conditioning and Activation of the Improved Heterogeneous Hydrogen Donor in a Pilot Plant

(20) In this section, as the sequence of example 1, the procedure for the thermal treatment and activation of the solid hydrogen transfer agent carried out in a pilot plant for the hydrotreating of heavy crude oils is described.

(21) a) Conditioning of the improved solid hydrogen transfer agent.

(22) 1. In a fixed-bed reactor, the improved solid hydrogen transfer agent is placed, a leak test using N.sub.2 is carried out at a pressure of 40 to 80 Kg/cm.sup.2.

(23) 2. The reactor is heated from 50 to 120 C., feeding a nitrogen flow between 100-500 ml/min, at atmospheric pressure. These conditions are maintained by 2-6 h

(24) 3. The temperature is increased from 400 C. to 450 C. and the pressure from 40 to 70 kg/cm.sup.2, maintaining a flow of N.sub.2 between 100-500 ml/min. These conditions are maintained for 10-24 hours.

(25) 4. The temperature is lowered to 120 C., the system is depressurized to atmospheric pressure maintaining the same flow of nitrogen. Maintain these conditions for 2-6 hours.

(26) b) Activation of the improved solid hydrogen transfer agent

(27) 1. The nitrogen flow is replaced by hydrogen of 100-500 ml/min, the pressure is increased from 40 to 70 Kg/cm.sup.2 and the temperature between 100 and 240 C. at a speed of 20 C./hour. Maintain these conditions for 2 to 6 hours.

(28) 2. The temperature is reduced to 120 C. at a speed of 50 C./hour, maintaining the same hydrogen flow and system pressure. When reaching 120 C., replace the flow of H.sub.2 with N.sub.2. Maintain conditions from 1 to 5 hours.

(29) 3. The pressure of the system is reduced to atmospheric maintaining the nitrogen flow between 100 and 500 ml/min. Maintain conditions between 2-6 hours. Elapsed the time, decrease the temperature to room temperature at a speed of 50 C./hour, maintaining the flow of N.sub.2.

Example 3. Thermal Stability of the Improved Solid Hydrogen Transfer Agents

(30) Gravimetric Thermal Analysis (TGA).

(31) To know the thermal stability of the improved solid hydrogen transfer agents, it was subjected to a thermal treatment of room temperature at 800 C. with a heating rate of 2.5 C./min. It was carried out in a nitrogen atmosphere and in an air atmosphere (FIG. 1). The behavior of the material in air and nitrogen atmosphere is very similar in the range of ambient temperature to 450 C. The improved solid hydrogen transfer agent loses about 8% by weight at 100 C. (water), after 450 C. the material begins to decompose, in an air atmosphere the decomposition is rapid due to the combustion of the organic polymer deposited; the remaining mass at 580 C. corresponds to the inorganic material AlO (OH). In an inert atmosphere, decomposition is gradual and incomplete at 800 C. and 70% by weight of the original material.

Example 4. Determination of the Average Molecular Weight of the Improved Solid Hydrogen Transfer Agent of the Example 1

(32) By gel permeation chromatography, the average molecular weight of the organic components of the improved solid hydrogen transfer agent was determined. The sample was diluted in tetrahydrofuran and injected to a chromatograph, the result corresponds to the analysis of the solubilized fraction of the material in tetrahydrofuran. Results are shown in table 2.

(33) TABLE-US-00002 TABLE 2 Molecular weight of the improved solid hydrogen transfer agent Average MW, g/mol Improved solid hydrogen transfer agent 600-700

Example 5. Effect of Improved Solid Hydrogen Transfer Agents in Hydrotreating a Heavy Crude

(34) In a pilot plant for the hydrotreatment of heavy crude oils, a test lasting 26 days was carried out, loading the reactor with the improved solid hydrogen transfer agent object of the invention, using a feedstock consisting of a heavy oil of 10.7 API and viscosity of 5.968 cSt measured at 37.8 C. (FIG. 2). The results obtained were the following: 3 degrees in API gravity gaining Viscosity of the improved crude from 100 cSt to 37.8 C. during the entire test Coke formation with the improved hydrogen donor of 0.1% weight based on the crude processing (0.5% weight in the test without hydrogen donor).

Example 6. Increase in Distillates Due to the Effect of Improved Solid Hydrogen Transfer Agents in the Hydrotreatment of a Heavy Crude

(35) In a pilot plant for the hydrotreatment of heavy crude oils, a test lasting 26 days was carried out, packing the reactor with the improved solid hydrogen transfer agent object of the invention, using a feedstock consisting of a heavy crude of 10.7 API and viscosity of 5.968 cSt measured at 37.8 C. The crude oil used as a feedstock and two samples of improved crudes obtained from the test at the beginning and at the end of the test were subjected to a TBP distillation (True Boiling Point, FIG. 3) to quantify the increase in distillates obtained with the solid hydrogen transfer agent object of the invention. The results obtained are illustrated in table 3:

(36) TABLE-US-00003 TABLE 3 Increase in distillates. upgraded crude oil Time on stream FEED Yields (% vol) (% vol) 24 h 528 h Naphta (0-221 C.) 12.45 15.13 15.38 Intermediate distillates 16.11 21.22 22.62 (221-360 C.) 360-538 C. 18.15 22.07 21.04 Residue 53.29 41.58 40.96