CATALYTIC GASIFICATION PROCESS, CATALYST, USE OF THE CATALYST AND PROCESS FOR PREPARING THE CATALYST

Abstract

The present invention relates to a catalyst to be applied to the process of gasification of coke or coal, individually or in mixture, and to the process of preparing said catalyst, which is useful in obtaining higher levels of hydrogen and carbon monoxide, which allows the conversion of coke into by-products of higher added value (hydrogen-rich syngas). The present invention also addresses to a process for converting petroleum coke by using a catalyst according to the present invention.

Claims

1. A CATALYTIC GASIFICATION PROCESS, characterized in that it comprises the following steps: a) loading the reactor bed; b) fluidizing the bed loaded in step (a), at room temperature, in an air flow rate of 10 Nl.Math.min.sup.−1; c) heating the bed fluidized in step (b), from room temperature to 800° C., at a rate of 20° C..Math.min.sup.−1; d) starting the intake of steam to the system heated in step (c); e) starting the intake of petroleum coke after reaching the gasification temperature, the stabilization of the temperature of the bed and the system; f) injecting the gas coming from the gasifier from step (e) into the chromatograph; g) cooling the system under an air stream; h) unloading the bed; i) weighing the bed unloaded in step (g), the cyclones and the filters; j) carrying out the mass balance of the unit.

2. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that the reactor bed is loaded with mixtures of catalyst and inert material in proportions of 10:90, wherein the proportion of the mixture preferably chosen is 50:50, of silica and catalyst, when catalytic gasification of petroleum coke, coal or a mixture of the same is carried out.

3. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that after the temperature of 300 to 700° C., preferably 500° C., is reached, the intake of steam begins with the liquid pump being calibrated for a supply of 5 ml.Math.min.sup.−1 or compatible with the size of the piece of equipment to be used.

4. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that after the gasification temperature is reached, there occurs the bed stabilization and the intake of petroleum coke at a rate of 0.366 kg.Math.h.sup.−1 or compatible with the piece of equipment to be used and the mass of raw material.

5. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that said process gives rise to a hydrogen-rich syngas, of high added value.

6. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that said process allows the reaction to occur under mild conditions and with higher conversion rates.

7. THE CATALYTIC GASIFICATION PROCESS according to claim 1, characterized in that the catalyst is supplied to the process without the need for a previous impregnation step or without the need for a previous mixing with the load.

8. A PROCESS FOR PREPARING A CATALYST FOR CATALYTIC GASIFICATION, characterized in that the following preparation steps are carried out: a) weighing 100 g of the support (quartz sand); b) weighing iron salt so as to have a desired iron content % (w/w); c) adding 150 ml of water to the iron salt; d) adding the prepared solution to the quartz sand; e) allowing to stand for 16 hours; f) evaporating the solution slowly; g) drying in an oven at 100° C./16 hours; h) calcinating at 550° C./5 hours.

9. THE PROCESS FOR PREPARING A CATALYST FOR CATALYTIC GASIFICATION according to claim 8, characterized in that the catalysts were prepared by the slurry method.

10. THE PROCESS FOR PREPARING A CATALYST FOR CATALYTIC GASIFICATION according to claim 8, characterized in that the catalysts were prepared at a determined support mass with a solution with the desired concentration of the metal.

11. THE PROCESS FOR PREPARING A CATALYST FOR CATALYTIC GASIFICATION according to claim 8, characterized in that the catalysts were prepared from a suspension formed and allowed to stand to then be dried and calcined.

12. THE PROCESS FOR PREPARING A CATALYST FOR CATALYTIC GASIFICATION according to claim 8, characterized in that the raw material used is, preferably, petroleum coke, wherein the maximum particle size is 177 μm.

13. A CATALYST FOR CATALYTIC GASIFICATION, obtained by the process defined in claim 8, characterized in that it comprises: a) a support, preferably quartz sand; b) a transition metal of group VIII; c) the calcination of the described compounds at 400 to 700° C., preferably at 550° C., with a time ranging from 2 to 10 hours and preferably within 5 hours.

14. THE CATALYST FOR CATALYTIC GASIFICATION according to claim 13, characterized in that the transition metal of group VIII comprises iron.

15. THE CATALYST FOR CATALYTIC GASIFICATION according to claim 13, characterized in that the catalyst can be of the following species: Fe/SiO.sub.2—NO.sub.3 and Fe/NO.sub.3—SO.sub.4.

16. THE CATALYST FOR CATALYTIC GASIFICATION according to claim 13, characterized in that it is used for the catalytic gasification of petroleum coke, coal and a mixture of both, wherein the raw material that is preferably used is petroleum coke.

17. THE CATALYST FOR CATALYTIC GASIFICATION according to claim 13, characterized in that it allows catalytic gasification to occur under milder conditions and with higher conversion rates of petroleum coke and coal.

18. THE CATALYST FOR CATALYTIC GASIFICATION according to claim 13, characterized in that the catalyst is supplied to the process without the need for a previous impregnation step or without the need for a previous mixing with the load.

19. A USE OF THE CATALYST, as defined in claim 13, characterized in that it is for the optimization and improvement of the catalytic gasification process of petroleum coke, coal or a mixture of both, wherein the raw material that is preferably used is coke.

20. THE USE OF THE CATALYST according to claim 19, characterized in that it results in a hydrogen-rich syngas and with high added value.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0040] The present invention will be described in more detail below, with reference to the attached figures which, in a schematic manner and not limiting the inventive scope, represent examples of its embodiment. In the drawings, there are:

[0041] FIG. 1 illustrates the conversion of petroleum coke as a function of time in thermal gasification and catalytic gasification at 800° C. using Fe/SiO.sub.2 catalysts prepared from chloride, nitrate and sulfate.

[0042] FIG. 2 illustrates the molar composition of the gasifier output stream (on a water and nitrogen free basis) in the test conducted at 800° C. with the Fe/SiO.sub.2—Cl catalyst.

[0043] FIG. 3 illustrates a molar composition of the gasifier output stream (with water and nitrogen free base) at 800, 750 and 700° C. with the Fe/SiO.sub.2—Cl catalyst.

DETAILED DESCRIPTION OF THE INVENTION

[0044] The present invention addresses to a catalytic gasification process of petroleum coke, coal or a mixture of the same, in order to generate hydrogen-rich syngas. The use of the catalyst provides milder conditions for processing the mentioned loads. Furthermore, the catalyst required in the present invention can be supplied together with the material to be processed, without the need for an impregnation step in the coke or previous mixing with coke or other materials.

[0045] The catalytic gasification process proposed in the present invention is carried out by means of the following steps: [0046] a) loading the reactor with a catalyst, an inert material or a mixture of both; [0047] b) fluidizing the bed loaded in step (a), at room temperature, in an air flow rate of 10 Nl.Math.min.sup.−1; [0048] c) heating the bed fluidized in step (b), from room temperature to 800° C., at a rate of 20° C..Math.min.sup.−1; [0049] d) starting the intake of steam to the system heated in step (c); [0050] e) starting the intake of petroleum coke after reaching the gasification temperature, the stabilization of the temperature of the bed and the system; [0051] f) injecting the gas coming from the gasifier from step (e) into the chromatograph; [0052] g) cooling the system under an air stream; [0053] h) unloading the bed; [0054] i) weighing the bed unloaded in step (h), the cyclones and the filters; [0055] j) carrying out the mass balance of the unit.

[0056] In one aspect of the invention, the reactor bed is loaded with 1 kg of silica and 1 kg of catalyst, to carry out the catalytic gasification process of petroleum coke or coal. On the contrary, in a thermal gasification, the reactor would be loaded with 2 kg of silica, this material being inert.

[0057] In another aspect of the invention, it should be emphasized that, after fluidizing the bed, the temperature of 500° C. is reached, starting the intake of steam to the system, in which the liquid pump is calibrated for a supply of 5 ml.Math.min.sup.−1.

[0058] In another aspect, when the gasification temperature in the system is reached, there occurs the bed stabilization and the intake of petroleum coke at a rate of 0.366 kg.Math.h.sup.−1.

[0059] Still in an additional aspect, it should be emphasized that, five minutes after the start of solids supply, the gas from the gasifier was injected into the in-line chromatograph in order to determine its composition. Samples of the gas stream were injected every thirty minutes. Once the entire coke mass was supplied, the injections continued until the presence of CO and H.sub.2 products was no longer detected, indicating the end of gasification.

[0060] When the gasification is ended and the room temperature reached, the bed is unloaded, followed by weighing the unloaded bed, the cyclones and the filters. Weighing is performed to determine whether there is a drag of particles from the bed, from petroleum coke or coal, depending on the case.

[0061] Regarding the aspect of the catalytic gasification process, it should be emphasized that said process gives rise to a hydrogen-rich syngas.

[0062] In yet another aspect of the catalytic gasification process, said process allows the reaction to occur under mild conditions and with higher conversion rates.

[0063] In addition to said aspect, the catalyst is supplied to the system without the need for impregnation in coke, coal or other similar material and without previous mixing with the load.

[0064] The second variation of the present invention addresses to a process for preparing a catalyst for catalytic gasification, described in several related aspects, among which the following preparation steps are included: [0065] a) weighing 100 g of the support (quartz sand); [0066] b) weighing the iron salt so as to have a desired iron content % (w/w); [0067] c) adding 150 ml of water to the iron salt; [0068] d) adding the prepared solution to the quartz sand; [0069] e) allowing to stand for 16 hours; [0070] f) evaporating the solution slowly; [0071] g) drying in an oven at 100° C./16 hours; [0072] h) calcinating at 550° C./5 hours.

[0073] In this variation, the catalysts were prepared by the slurry method, in which a determined mass of support, together with a solution, which makes up a desired concentration of the metal, are mixed forming a suspension. The solution with the suspension formed is allowed to stand and then dried and calcined.

[0074] In all variations of the present invention, the raw material used to obtain a hydrogen-rich syngas is, preferably, petroleum coke, in a maximum particle size of 177 μm. However, it is possible that the catalyst is used for the gasification of coal.

[0075] The catalyst mentioned in the previous variations of this invention is also required as an innovative product. In this way, the obtained catalyst for catalytic gasification comprises: [0076] a) a support, preferably quartz sand; [0077] b) a transition metal of group VIII; [0078] c) the calcination of the narrated compounds at 550° C./5 hours.

[0079] It should be emphasized that, in this third variation of the invention, the catalyst for catalytic gasification comprises a transition metal of group VIII, namely iron. There are three forms of catalyst required in this invention, FeSiO.sub.2—Cl, FeSiO.sub.2—NO.sub.3 and the third species, FeSiO.sub.2—SO.sub.4.

[0080] Among the species mentioned, FeSiO.sub.2—Cl showed a reduction in time for conversion and increased the levels of CO.sub.2 and H.sub.2 in the reaction, compared to the thermal conversion. Thus, the catalyst for catalytic gasification FeSiO.sub.2—Cl allows catalytic gasification to occur under milder conditions and with higher rates of conversion of petroleum coke and by similarity to coal.

[0081] In another way, the catalyst for catalytic gasification further has an additional advantage, since it is supplied to the system without the need for impregnation in coke, coal or other similar material and without the need for previous mixing with the load, reducing the processing steps, the processing time and the energy expenditure.

[0082] Therefore, the use of the catalyst for catalytic gasification, optimizes and improves the catalytic gasification process of petroleum coke or coal, giving rise to a hydrogen-rich syngas and of high added value. Additionally, it is a low-cost catalyst due to the materials used and the preparation method.

Examples

[0083] As can be seen in the performed tests, the catalysts were prepared by the slurry method, which consists of adding a solution to a determined support mass with a desired concentration of the metal. The formed suspension is allowed to stand and then dried and calcined. The steps for preparation were: [0084] a) weighing 100 g of the support (quartz sand); [0085] b) weighing the iron salt to a desired iron content % (w/w); [0086] c) adding 150 ml of water to the iron salt; [0087] d) adding the prepared solution to the quartz sand; [0088] e) allowing to stand for 16 hours; [0089] f) evaporating the solution slowly; [0090] g) drying in an oven at 100° C./16 hours; [0091] h) calcinating at 550° C. for 5 hours.

[0092] The coke used in the tests was ground and subjected to a granulometric classification using a set of sieves, by having collected and stored the fraction with a maximum particle size of 177 μm. Table 1 addresses to the composition of the various catalysts prepared, determined by X-ray fluorescence (FRX).

TABLE-US-00001 TABLE 1 Composition of several prepared catalysts obtained by FRX. Fe Source SiO.sub.2 (% w/w) Fe.sub.2O.sub.3 (% w/w) Fe (% w/w) Fe(NO.sub.3).sub.3•9H.sub.2O 87.8 12.2 8.54 FeCl.sub.2•4H.sub.2O 92.9 7.1 4.97 Fe.sub.2(SO.sub.4).sub.3•xH.sub.2O 96.4 3.6 2.52

[0093] FIG. 1 demonstrates the conversion of petroleum coke as a function of gasification time, at a temperature of 800° C., when Fe/SiO.sub.2 catalysts prepared from the use of chloride, sulfate and nitrate were used. For comparative purposes, the coke conversion curve obtained for thermal gasification, without the presence of catalyst, was included.

[0094] Blank tests and tests performed to test the conversion effectiveness of each catalyst were carried out by testing the following protocol: [0095] a) Loading of the reactor bed, which may consist of 2 kg of silica (thermal gasification test) or 1 kg of silica and 1 kg of catalyst (catalytic gasification test); [0096] b) Fluidization of the bed, at room temperature, using an air flow rate of 10 Nl.Math.min.sup.−1; [0097] c) Heating of the bed, from room temperature to 800° C. using a rate of 20° C..Math.min.sup.−1; [0098] d) When the temperature of 500° C. was reached, the intake of steam to the system was started, and the liquid pump was calibrated for a supply of 5 mL.Math.min.sup.−1; [0099] e) When the desired gasification temperature was reached, the stabilization was awaited. As soon as the bed temperature stabilized, the intake of petroleum coke was started at a rate of 0.366 kg.Math.h.sup.−1; [0100] f) Five minutes after the start of solids supply, the gas from the gasifier was injected into the in-line chromatograph in order to determine its composition. Samples of the gas stream were injected every thirty minutes. Once the entire coke mass had been supplied, the injections continued until the presence of CO and H.sub.2 products was no longer detected, indicating the end of gasification; [0101] g) The system was cooled under an air stream and, once reached room temperature, the bed was unloaded and weighed. The cyclones and filters were also weighed to determine whether particles had been dragged from the bed or from the petroleum coke, thus closing the mass balance of the unit.

[0102] After the performed tests, it was possible to observe that the Fe/SiO.sub.2 catalyst prepared from sulfate presented a performance similar to that observed in the thermal gasification. This result can be explained if it is considered that the content of iron incorporated into the silica, when sulfate was used as a source of the metal, was below the others. Such information can be corroborated by Table 1.

[0103] In the case of the catalyst prepared using nitrate as a source of iron, the incorporated content was above the other two, but also in this case, there was no significant improvement in the conversion of petroleum coke, compared to thermal gasification. In particular, the catalyst prepared from the nitrate showed a similar performance to the catalyst prepared from the sulfate until about 100 minutes, when a decrease in performance started, even with respect to thermal gasification.

[0104] The use of the Fe/SiO.sub.2—Cl catalyst seems to have influenced the gasification kinetics of petroleum coke, since the total conversion was reached in 4 hours of reaction, compared to the 6 hours necessary in the thermal gasification and in the reactions carried out by using Fe/SiO.sub.2—NO.sub.3 and Fe/SiO.sub.2—SO.sub.4 catalysts.

[0105] FIG. 2 shows the molar composition of the gasifier output stream (on a water and nitrogen-free basis) in the test conducted at 800° C. with the FeSiO.sub.2—Cl catalyst. In the experiment using the Fe/SiO.sub.2—Cl catalyst, higher contents of CO.sub.2 and H.sub.2 were obtained, as shown in FIG. 2. This result suggests that, in addition to being effective in reducing the total gasification time, this catalyst greatly promoted the reaction of gas-water displacement, thus increasing the production of hydrogen.

[0106] As can be seen in FIG. 3, there is the molar composition of the gasifier output stream (on a water and nitrogen-free basis) in the test conducted at 800, 750 and 700° C. Such data demonstrate that, in the additional tests referenced in FIG. 3, the conversion is reduced at lower temperatures and there is also a progressive increase in the gasification time to reach the final conversion. On the other hand, the conversion observed at 750° C. is close to the purely thermal conversion, without the presence of catalyst, as shown in FIG. 1. Accordingly, it can be noted that in the presence of the catalyst object of this innovation, lower temperatures are required to achieve conversions equal to those of the purely thermal reaction, making the whole process less energy intensive.

[0107] It should be noted that, although the present invention has been described in relation to the attached drawings, it may undergo modifications and adaptations by technicians skilled on the subject, depending on the specific situation, but provided that it is within the inventive scope defined herein.