MXPA97004212A - Method for descenting a parc oxidation reactor - Google Patents

Abstract

A method for facilitating the separation of slag from a partial oxidation reactor for the production of syngas is described. The slag comprises vanadium trioxide and a siliceous vitreous material which accumulates on the inner walls (17) of the partial oxidation reactor (1) as a by-product of the production of syngas. The deslagging is carried out by controlled oxidation, wherein the vanadium / glass weight ratio is maintained at least about 3: 2, the reactor (1) operating at a temperature of at least about 1093 ° C and maintaining sufficient controlled oxidation conditions to convert vanadium trioxide from slag to vanadium pentoxide

Description

METHOD FOR DESCENTING A PARTIAL OXIDATION REACTOR BACKGROUND PE THE INVENTION Field of the Invention This invention relates to the addition of small amounts of a vanadium-containing material to petroleum-based feedstocks used in partial oxidation reactions. The vanadium additions facilitate the deslagging of the partial oxidation reactor. Description of the State of the Art Petroleum-based feedstocks include impure petroleum coke and other hydrocarbonaceous materials, such as waste oils and by-products derived from heavy crude oil. These feedstocks are generally used in partial oxidation reactions that produce mixtures of hydrogen and carbon monoxide gases, usually referred to as "synthesis gas" or simply as "syngas". Syngas is used as a feedstock to prepare a multitude of useful organic compounds and can also be used as a clean fuel to generate energy. Syngas feeds generally contain significant amounts of contaminants such as sulfur and various metals such as vanadium, nickel and iron. The charge, including the feedstock, gas containing free oxygen and any other materials, is supplied to the partial oxidation reactor. The partial oxidation reactor is also known as "partial oxidation gasifier reactor" or simply as "reactor" or "gasifier" and all these terms will be used interchangeably throughout the present description. Any effective means can be employed to feed the feedstock into the reactor. In general, the feedstock and gas are added through one or more reactor inlets or openings. Normally, the feed material and gas are passed to a burner located at the reactor inlet. Any effective burner design can be used to facilitate the addition or interaction of feedstock and gas in the reactor, such as an annular corona type burner described in US Patent No. 2,928,460 to Eastman et al., US Pat. No. 4,328,006 to Muenger et al. or US Patent No. 4,328,008 to Muenger et al. Alternatively, the feedstock can be introduced into the upper end of the reactor through a door. The gas containing free oxygen is usually introduced at high speed into the reactor either through the burner or through a separate door that discharges the oxygen gas directly into the stream of feedstock. According to this arrangement, the materials of the charge are intimately mixed within the reaction zone and the oxygen gas stream is prevented from directly incident on the walls of the reactor producing the consequent damages thereto. Any effective reactor design can be used. Normally, a vertical pressure vessel of cylindrical configuration can be used. Examples of reactors and related apparatus are described in US Patent No. 2,809,104 to Strasser et al., US Patent No. 2,818,326 to Eastman et al., US Patent No. 3,544,291 to Schlinger et al., Patent. U.S. Patent No. 4,637,823 to Dach, U.S. Patent No. 4,653,677 to Peters et al., U.S. Patent No. 4,872,886 to Henley et al., U.S. Patent No. 4,456,546 to Van Der Berg, U.S. Patent No. 4,671,806 to Stil et al., US Patent No. 4,760,667 to Eckstein et al., US Patent No. 4,146,370 to Van Her ijner et al., US Patent No. 4,823,741 to Davis et al. , US Patent No. 4,889,540 to Segerstrom et al., US Patent 4,959,080 to Sternling and US Patent No. 4,979,964 to Sternli-ng. The reaction zone preferably comprises a refractory and free-flowing flow-through chamber with an inlet located centrally in the upper part and with an outlet axially aligned in the lower part. The refractory can be any effective material for a partial oxidation reactor. The refractory can be prefabricated and installed, such as refractory bricks, or it can be formed in the reactor, such as a ceramic ceramic material. Typical refractory materials include at least one or more of the following: metal oxides, such as chromium oxide, magnesium oxide, ferrous oxide, aluminum oxide, calcium oxide, silica, zirconia and titania; phosphorous compounds; and similar. The relative amount of refractory materials can be found in any effective proportion. The partial oxidation reaction is carried out under reaction conditions which are effective and sufficient to convert a desired amount of feedstock to syngas. The reaction temperatures usually range between about 900 and 2000CC, preferably between about 1200 and 1500 ° C. The pressures generally range from approximately 1 to 250 atmospheres, preferably from approximately 10 to approximately 200 atmospheres. The average residence time in the reaction zone generally ranges from about 0.5 to 20 seconds and usually from about 1 to about 10 seconds. The partial oxidation reaction is preferably carried out under highly reducing conditions for the production of syngas. Generally, the concentration of oxygen in the reactor, calculated in terms of partial pressure, during partial oxidation, is less than about 10"5 atmospheres and is normally about 10" 12 to 10"ß atmospheres.

The partial oxidation of impure petroleum coke or other suitable petroleum-based feedstock having contaminating materials produces a by-product of slag that can accumulate and form deposits on the inner surface of the reactor or in the lower throat of the reactor and in the exit of the reactor, to such a degree that blockages may occur, which will prevent effective partial oxidation from being carried out. Therefore, it becomes necessary to periodically shut off the partial oxidation reactor to remove the slag, in an operation generally known as "controlled oxidation" or "deslagging". Controlled oxidation conditions are employed in the partial oxidation reactor to fluidize or melt the slag so that it can be removed by pulling it out of the reactor, thereby enabling the reactor to return to the partial oxidation operation. Petroleum-based feedstocks, such as impure petroleum coke, generally contain vanadium as a major ash constituent along with various amounts of alumina, silica and calcium. During the partial oxidation reaction to form syngas, the constituents of alumina, silica and calcium from the petroleum coke feed tend to form a siliceous vitreous matrix surrounding vanadium, which is mainly in the form of trioxide crystals. of vanadium (V203).

The ash particles formed as a by-product of the syngas reaction will impinge and adhere to the inner surface walls of the reactor and, depending on the melting temperature of the ash, will accumulate in the form of slag or flow out of the reactor. In this way, the slag consists of essentially fused mineral matter, a byproduct of the material that deposits slag from the petroleum-based feed. The slag may also contain carbon in the form of carbon, soot and the like. The composition of the slag will vary depending on the type of material that deposits slag present in the petroleum-based feed, the reaction conditions and other factors that influence the deposition of slag. Normally, the slag is composed of oxides and sulfides of slag-forming elements. For example, slag derived from impure petroleum coke or "resid" normally contains siliceous material, such as crystal, and crystalline structures such as wollastinite, gelenite and anorthite; vanadium oxide, generally in the trivalent state, V203; spinel having a composition represented by the formula AB204 wherein A is iron and magnesium and B is aluminum, vanadium and chromium; sulfides of iron and / or nickel; and metallic iron and nickel. Slag having a melting temperature below the reactor temperature can melt and exit the reactor as molten slag. Since V203 has a high melting point of about 1970 ° C, the presence of higher amounts of V203 in the slag will increase the slag melting temperature. Slag having a melting temperature higher than the temperature of the reactor generally forms solid deposits in the reactor, which normally adhere to the surfaces of the refractory material coating the reactor. The slag deposits increase as the partial oxidation reaction proceeds. The speed at which the slag accumulates can vary widely depending on the concentration of slag depositor material present in the feed material, the reaction conditions, the use of washing agents, the configuration and size of the slag. reactor and other factors that influence the accumulation of slag. The amount of slag accumulated eventually reaches a level at which the removal of slag from the reactor becomes desirable or necessary. Although slag removal can be carried out at any time, the partial oxidation reaction is normally continued to the greatest extent possible to maximize the production of syngas. SUMMARY OF THE INVENTION In accordance with the present invention, the removal of slag from a partial oxidation reactor during the controlled oxidation conditions, can be facilitated by keeping the gasifier at a temperature that is at least at the initial melting temperature of the siliceous vitreous component of the slag, and controlling the vanadium / crystal ratio in the slag to maximize the exposure of the vanadium trioxide, V203, to sufficient oxidizing conditions to convert the high melting point slag component V203 to the lower melting point vanadium pentoxide, V205, whose phase it then destroys the siliceous vitreous matrix, thereby allowing the deslagging of the partial oxidation gasifier reactor below the gasification temperature. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 is a partial pressure diagram in equilibrium showing the minimum partial pressure of oxygen required to convert V203 to V205. Figure 2 is a cross section of a partial oxidation reactor. DESCRIPTION OF THE PREFERRED MODALITIES It has been found that the addition of small amounts of vanadium-containing material to petroleum-based feedstocks that undergo partial oxidation in a partial oxidation reactor will improve slag removal during operation. of deslagging of the reactor under conditions of controlled oxidation. During the gasification reaction by partial oxidation of a petroleum-based feedstock, such as coke, the vanadium present in the feed coke material formed V203 crystals, while the alumina, silica and calcium form a siliceous crystal, each one of which may leave the reactor as ash particles or may impinge on the internal walls of the reactor and accumulate there in the form of slag, depending on the melting temperature of the ash. The siliceous vitreous material of the slag forms a matrix or phase surrounding the vanadium trioxide crystals. The introduction of oxygen into the partial oxidation reactor during controlled oxidation causes the oxidation of V203 to V205. This reaction has an effect on the siliceous vitreous material as it is to allow the slag to fluidize and exit the reactor. The V20s attacks and breaks the surrounding silicic vitreous and interlacing phase to separate small spherical particles that will flow out of the reactor with the molten vanadium slag below normal gassing temperatures of approximately 1145 to 1760 ° C. In order for the attack action of vanadium pentoxide to be effective on the siliceous vitreous portion of the slag, the vanadium / crystal ratio must be carefully controlled. As the relative crystal / vanadium ratio increases, the vitreous phase will inhibit the oxidation of V203 crystals and form an interlocking network of siliceous crystals that impede the flow of the slag. The amount generated of V205 is not enough to break the s-illicit matrix. If the coke ash has too low a vanadium content, then vanadium or a vanadium-rich material must be added to the coke feed undergoing partial oxidation to increase the vanadium / crystal ratio. Vanadium can be obtained from the soot generated during the gasification of the oil, from the coal coming from other coke gasifiers, from the vanadium existing in the market or from any other material rich in vanadium. The vanadium / crystal ratio in the slag can generally vary between about 7: 1 and 1: 2 by weight, respectively. A minimum weight ratio of vanadium to glass of approximately 2: 1 is necessary to ensure the destruction of the siliceous vitreous phase during controlled oxidation. The vanadium content of the slag can vary between approximately 60 and 80% by weight. The siliceous crystal content of the slag can vary between about 20 and 30% by weight.

Below a vanadium to glass ratio of about 3: 2, the slag becomes less viscous and will begin to flow into the lower throat of the reactor during gasification and may solidify, causing clogging, due to the rapid change in temperature gradient and at the lowest temperature in the throat of the reactor. Below the vanadium / crystal ratio of 3: 2, the addition of vanadium should be made to increase the ratio to at least 2: 1. Because the amount of ash in most petroleum-based feedstocks is low, the amount of vanadium needed to change the vanadium / crystal ratio in the slag is small. For example, for a typical petroleum-based feed, it is sufficient to make vanadium additions of from about 0.01 to 20% by weight, preferably from about 0.05 to 3% by weight, more preferably from Q1 to 2.5% by weight. weight approximately and especially from 0.5 to 2% by weight approximately, to increase the vanadium / crystal ratio to at least 2: 1. To obtain maximum deslagging rates, the temperature of the gasifier during controlled oxidation should be at approximately the initial melting temperature of the siliceous vitreous material, generally between about 1090 and 1370 ° C, preferably between about 1200 and 1260 ° C. In one embodiment of the invention, the slag may be allowed to accumulate in the reactor until the diameter of the lower throat begins to decrease as a result of slag accumulation. The gasification reaction by partial oxidation will then be stopped and controlled oxidation conditions will be introduced into the reactor in order to remove the slag. During the controlled oxidation reaction, the oxygen partial pressure increases in the gasifier to convert the high melting temperature phase V203 to the lower melting temperature plunger phase. Any gas containing free oxygen and containing said oxygen in a form suitable for the reaction during the partial oxidation process may be employed. Typical gases containing free oxygen include one or more of the following: air; air enriched in oxygen, that is, air that has more than 21 mol% oxygen; substantially pure oxygen, that is, with more than 95 mol% oxygen; and other suitable gases. Generally, the gas containing free oxygen contains oxygen plus other gases derived from the air from which the oxygen was prepared, such as nitrogen, argon or other inert gases. The proportion of petroleum-based feedstock containing free oxygen, as well as any optional components, may be any amount that is effective in preparing syndes. Normally, the atomic oxygen ratio of the gas containing free oxygen to carbon, in the feedstock, is from about 0.6 to 1.6, preferably from 0.8 to about 1.4. When the gas containing free oxygen is substantially pure oxygen, the atomic ratio may be from about 0.7 to about 1.5, preferably about 0.9. When the gas containing oxygen is air, the ratio can be from about 0.8 to 1.6, preferably about 1.3. Figure 1 is a diagram of partial pressure of oxygen in equilibrium-temperature at one atmosphere and shows the partial pressure of oxygen necessary to convert V203 to V205 and the temperature parameters that allow the reactor to operate in two different regimes of Simultaneously. As shown in Figure 1, when operating at point 10 above and to the left of equilibrium curve 12, the partial pressure of oxygen is sufficient to oxidize V203 in the lower section of the reactor, so that The resulting V205 liquefies at the operating temperature. The partial pressure of oxygen increases in a generally gradual manner during the controlled oxidation from approximately 2% to 10% at a pressure of approximately 1-200 atmospheres in the partial oxidation reactor, for example, for a period of 1 to 24 hours. Other materials may optionally be added to the feed material or gasification process. Suitable additives may be provided such as fluxing or washing agents, temperature moderators, stabilizers, viscosity reducing agents, purging agents, inert gases or other useful materials. An advantage of the process of the invention is that the impure petroleum coke can be gasified to produce syngas and the reactor can then be dessicated using controlled oxidation, which is less expensive than using a washing agent or waiting for it to cool the reactor to proceed then to effect a mechanical deslagging. In addition, because the slag can be recovered, the maintenance of solids is reduced and a greater carbon conversion is achieved. The calcium content of coke ash is also important, because lower amounts of calcium will increase the viscosity of the slag during gasification, thus inhibiting flow or entrainment. Higher amounts of calcium will increase the rate of controlled oxidation by allowing the silicon crystal to break more quickly. Therefore, the amount of calcium in the slag should be sufficient to lower the melting point of the crystal to 1260-1370ßC. Therefore, for coke feeds having less than about 10 wt.% CaO in the crystal-forming compounds, such as A1203, Si02, CaO + MgO and FeO, it may be beneficial to make small additions of the order of 0.03. -0.5, preferably 0.05-0.25, and more preferably 0.1-0.2 kg approximately calcium per ton of petroleum-based feed, to thereby increase the rates of deslagging by allowing the glass to break more quickly at lower temperatures. This in turn improves the life of the refractory material by reducing the exposure time to V205. Calcium can be found in the form of calcium carbonate, calcium oxide or other equivalent compounds. In the following examples and throughout this description, the parts and percentages are indicated by weight, unless otherwise specified. Example 1 Two partial oxidation gasifiers, Gasifier A and Gasifier B, each with the configuration illustrated in Figure 2, were operated according to the partial oxidation mode and then stopped to allow the accumulated slag deposits to cool during partial oxidation. In Figure 2, the partial oxidation reactor 1 is constituted by a pressurized steel vessel of cylindrical configuration 2 coated with refractories 3 and 4. The refractory of the lower part 5 is inclined towards the outlet of the throat 6. The burner 7 passes through the inlet 8 in the upper part of the reactor 1. The reactor is also equipped with a pyrometer and thermocouples, not shown, to control the temperature of the reactor in the upper, intermediate and lower parts of the reaction chamber. For partial oxidation, the feedstock is introduced through line 10 to an inner annular passage 11 of the burner 7. The gas containing free oxygen is fed via lines 12 and 13 to the central and outer annular passageways 14 and 15, respectively. The partial oxidation reaction is carried out at temperatures of about 1200 to 1500 ° C and at pressures of about 10 to 200. The feed material reacts with the gas in the reaction chamber 16 to produce synthesis gas and byproducts including slag which it accumulates on the inner surface 17 of the reactor 1 and at the outlet 6. The synthesis gas and the fluid by-products leave the reactor through the outlet 6 to enter a cooling chamber or container, not illustrated, for further processing and recovery The non-gas byproduct slag impinged on the surfaces inside the reactor adhering to them. The slag obtained from Gasifier A was classified as a moderately siliceous scoria with a high vanadium content containing approximately 20% silicates. The slag obtained from Gasifier B was classified as a highly siliceous, low vanadium slag containing approximately 42% silicates. The slag from Gasifier B did not get to fluidize when oxidized at a temperature of 1315 ° C under air. The slag of Gasifier A fluidized under air at 1205 ° C. From Gasifiers A and B samples of 5 cm x 5 cm x 5 cm of non-oxidized slag were removed and said samples were oxidized at temperatures of 1050 ° C and 1315 ° C. After cng to a temperature of 21 ßC, the samples were prepared for analysis by electron microscopy (SEM). The SEM was equipped with an energy dispersive X-ray spectrometer (EDS). For the chemical analysis, a standardized quantitative analysis using a PROZA correction routine was used. Additional phase analysis was performed using reflective light microscopy. Tables 1 and 2 show that the slag from Gasifiers A and B experienced similar reactions when going from a reducing atmosphere to an oxidizing atmosphere. The nickel present in the form of nickel sulfide was combined with the alumina of the vitreous phase to form spinels. The metals calcium, iron, magnesium, molybdenum or similar metals in the valence +2 phase of vitreous and oxidized phases, formed phases of MV206 (where M = Fe, Ca, Mg, Mo, etc.) that constituted the fluid phase predominant carrier in the oxidized slag. The crystal was converted to more crystallized phases enriched with silica. Depending on the oxidation temperature (for example, 1050 ° C and 1315 ° C), the degree of change in the vitreous phase varied. Analysis of slag B indicated that at 1050 ° C the vanadium oxide did not completely destroy the vitreous phase, but left behind an alumina-silica network and silica-rich slats that inhibited slag flow. At 1315 ° C, the slats became small spherical crystals that were not interconnected and, therefore, could be washed from the reactor by the MV206 slag flux. The nickel sulphide of the slag formed nickel-alumina spinels at temperatures of 1050 ° C and 1315 ° C.

TABLE 1 Chemical analysis (SEM-EDX:% by weight) GASIFICATOR A Mg Al Si s Ca y. C Ee Ni Reduced 2.3 3.3, 7.2 9.1 6.3 41.8 20.8 7.6 Oxidated 3.2 5.1 10.4 0.2 9.7 46.6 0.7 17, 6 6.2 1050 ° C vo Mass 1.3 0.5 13.3 0 7.6 54.7 0 17.6 4.4 i Mass 1.1 1.1 11.9 0 5.1.1 37.1 0.7 31 11.5 Phase 1 tabular crystals 5.1 0 0.3 0 3.4 53.1 0 33.8 3.2 Phase 2 spinels 1.5 6.4 0.3 0 0 3.2 0.3 59.3 28.8 Stage 3 laths 0,3 0 84,2 0 0,3 12,7 0 0,9 0 Phase 4 laths' 1,6 0 0 0 20,6 74,3 0,9 1,4 1,1 Mg? I Si CU Cr Fe. ÍÜ 1315 ° C Mass 0.6 4.8 12.8 0. 6.7 49.5 X 18.2 6.1 Phase 1 tabular crystals 2.6 1.2 0 0 0.1 56.9 X 35.1 3.3 Phase 2 spinels 2.7 23.9. 3.6 0 0.2 3.8 X 31.8 33.6 Phase 3 spheres 0.2 3.1 73.3 0 2.4 12.9 X 2.6 0.4 Phase 4 strips 0.2 0 0 0 22.4 72.9 X 4.1 0 ro O TABLE 2 Chemical analysis (SEM-EDX:% by weight) GASIFICATOR B Mg AI si s Ca V CE £ = Ni Reduced (layer 1) X 14.7. 9.3 11.4 0.6 36.4 X 11, 5 15, 9 Reduced (layer 2) X 2.1 1.6 3.2 0.4 81.6 0 3, 9 6.2 Oxidated X 14 , 1 4,1 1,7 0 59,8 0 5, 6 14,1 1 1Q5Q ° C Mass 9.23 13.9 16.2 0 0 35.1 0, 4 8.6 15.3 Phase 1 spinel 0 28.7 0.5 0 0 3.1, or 2 17.9 49.4 Phase 2 tubular crystals 20.9 2.4 0 0 0 34.9 0 18.3 18.7 Phase 3 laths 11.4 4.2 0.9 0 0 77.3 0 2.1 0.6 Phase 4 ribbon '1.9 0 85.7 0 0 9.6 0 0.8 1.7 Phase 5 ribbon 0.7 33.9 42.5 0 0 19.9 0 0.5 1.1 Mg? I Si Ca Cr Fe. Ni 1315 ° C Mass 10.1 12.9 20.4 0 0.2 35.9 0 7.9 11.5 Mass 6.9 16.2 15.8 0 0.3 34.5 0 9.8 15.7 Phase 1 tabular crystals 1 177,, 66 0.9. 0 0 0 37.1 0.3 20.8 18.3 Phase 2 strips 14,1 0,7 0,2 0 0 83,6 0 0,7 0,5 Phase 3 hexagonal crystals 0 0 0 97.4 0 0.6 2.1 0 0 0 Phase 4 strips 3.9 42.3 22.1 0 0.2 25.1 0.4 3.7 1.8 t t Phase 5 spinel 0 34.4 1.2 0 0 2.7 0.2 17.5 43.6 1 The slag from Gasifier B contained more glass and less vanadium than the slag from Gasifier A, whereby the slag from Gasifier B was below the 2: 1 limit. During gasification, the slag from Gasifier B formed layers that were rich in silicon crystal. The oxidation of the slag at 1050 ° C formed an interlaced network of alumina-silica crystals that supported the vanadium oxide. The molybdenum and iron vanadates formed interstitial phases between the silicates. At 1315 ° C, some silica-rich spheres were formed, but most of them were intertwined, there was no indication that vanadium oxide dissolved the silica in the spheres, so even in the course of time, the The silicate network remained intact and the slag did not flow from the reactor.The formation of a large amount of nickel-alumina spinels would also increase the viscosity of the slag in the event that the silica dissolved. a high glass content and a lower vanadium content did not break at 1315 ° C, while the A-Gasifier slag, with approximately half the crystal content, broke completely at 1205 ° C due to the interaction of V205 with The crystal Example 2 Cones of synthetic slag-like material were formed with the following composition: a vitreous phase consisting of 65% by weight of SiO2, 20% by weight of A1203, 10% by weight of CaO. and 5% by weight of FeO, with V203 ratios: crystal of 10: 0, 9: 1, 4: 1, 7: 3, 1: 1, 3: 7 and 0:10. These compositions are offered in the following Table 3. TABLE 3 Relation Crystal composition y.2O3: Crystal Results * Si02 - 65% by weight 9: 1 (Exp. 1) Cone completely destroyed A1203 - 20 8: 2 (Exp. 2) Cone fundamentally destroyed CaO - 10 7: 3 (Exp. 3) Cone partially destroyed FeO - 5 6: 4 (Exp. 4) Cone vitrified and intact Test 2 Si02 - 65% by weight 7: 3 Cone completely destroyed A1203 - 25 CaO - 10 Test 3 Si02 - 65% by weight 7: 3 Cone intact A1203 - 30 CaO - 5 Test 4 Si02 - 20% by weight 7: 3 Cone partially destroyed A1203 - 50 CaO - 30 Test 5 Si02 - 55% by weight 7: 3 Cone destroyed A1203 - 0 CaO - 45 Results based on visual appearance and SEM analysis A Leco ash deformation unit was used to study the effects of changing the ratio of vanadium oxide to glass (FeO + CaO + Si02 + Al203) on: i) the initial deformation temperature of a series of synthetic scoria rich in vanadium under the conditions of the gasifier and ii) the flow characteristics of the synthetic slag during oxidation. The composition of the slag was kept constant during each individual test and two different crystal compositions were employed. The experiments were conducted under a 60:40 mixture of C0: C02 during heating to keep the vanadium reduced to the +3 valence state. Depending on the test to be performed, the mixture CO: C02 or i) remained during the cooling or ii) once the deformation temperature was obtained, the supply of the mixture was cut off and the purging of air inside the unit was allowed. After cooling with air, the amount of deformation of the cones was noted and samples prepared for the SEM analysis. To determine the effects of the crystal composition on the oxidation rate of the cone, the amounts of CaO + Al203 + SiO2 in the cones having a vanadium oxide / crystal ratio of 7: 3 were changed. The cones were heated to 1538 ° C under reducing gas.The air was allowed into the unit while the samples were cooling.After cooling, the samples were visually inspected and arranged for SEM analysis.The synthetic slag cones contained between 50 and 70% by weight of siliceous material were deformed under reducing conditions, as shown in Tables 4 and 5. With 80% crystal and 20% vanadium oxide, the deformation occurred at a temperature as low as 1290 ° C. The initial composition of the crystal determined the point of deformation of the slag.Thus, the higher the CaO content, the lower the deformation temperature TABLE 4 Cones Deformation Test Starting material Predicted Fusion: 1321 ° C A1203 20% Si02 65% CaO 10% FeO 5% Temp. Temp. Temp. reblansemi- Temp. y2c3 Initial crystal spherical clearance Huida 0 100 2385 2411 2426 2427 90 2374 2397 2415 2417 80 2436 2484 2510 2512 70 2670 2800 2800 2800 50 50 2800 2800 2800 2800 90 10 2800 2800 2800 2800 ?? B_LA_5_ Cones Deformation Test Crystal starting material. Predicted melting point: 1249 ° C A1203 13.9% SiO2 51.2% CaO 17.9% FeO 7.8% MgO 4.1% Other 5.1% Temp. Temp. Temp. reblansemi- Temp. y2c3 Initial crystal fluid spherical clearance 0 100 2108 2122 2141 2142 90 2108 2122 2141 2142 80 2145 2196 2340 2341 70 2351 2707 2800 2800 50 50 2800 2800 2800 _ 2800 90 10 2800 2800 2800 2800 Microscopic analysis of the samples indicated that the cones, before the test, consisted of a network of interlinked vanadium crystals within the crystal. These structures were similar to those found in the actual slag deposits, except that the vanadium oxide crystals were larger in the sample cones. During oxidation, synthetic cones having less than 20 wt% silicon crystal content were destroyed. The cones that had 30% of glass lost material, as was evident by the reduction in size, but still retained their forms. The cones containing more than 40% by weight of siliceous material remained intact and did not appear to lose much vanadium oxide. Microscopic analysis of the cones indicated that the vitreous phase broke to separate siliceous particles during oxidation. These irregularly shaped silicates provided a structure to support the cones once the vanadium oxide was converted to vanadium pentoxide (V205). Cones with higher calcium content and lower silica content lost more material during oxidation than cones with higher silica content. The analysis indicated that most of the calcium appeared to have been eliminated from the cone by vanadium during the oxidation process, leaving behind a structure rich in alumina and poor in vanadium. The higher silica content material also contained calcium vanadates in the pores, but the silicate phase remained irregularly shaped in an interlaced structure.

Claims (20)

1. NOVEPftP PE Lft INVENTION Having described the present invention, it is considered as novelty and, therefore, the content of the following claims is claimed as property: 1.- A method to facilitate the separation of slag from a partial oxidation reactor, in where a petroleum-based feedstock containing a slag deposit material is partially oxidized with an oxidizing gas to produce syngas and a slag by-product comprising vanadium, mainly in the form of V203, and a siliceous crystal material, and in where the deslagging of the reactor is carried out under controlled oxidation conditions to convert the V203 component of higher slag melting point to V20s, comprising: (a) controlling the weight ratio V203 / glass of the slag in the reactor during the partial oxidation in an amount greater than 3: 2; and (b) replacing the partial oxidation conditions by controlled oxidation conditions and increasing the partial pressure of the oxidizing gas to an amount sufficient to convert V203 to V205.
2. 2. A method according to claim 1, characterized in that the V203 content of the slag varies between approximately 60 and 80% by weight.
3. 3. - A method according to claim 1, characterized in that the siliceous crystal content of the slag varies between approximately 20 and 30% by weight.
4. 4. A method according to claim 1, characterized in that the slag is a by-product of the gasification reaction of a petroleum-based feedstock.
5. 5. A method according to claim 4, characterized in that a material containing vanadium is added to the petroleum-based feedstock in an amount ranging from 0.01 to 20% by weight approximately of the petroleum-based feedstock.
6. 6. A method according to claim 5, characterized in that the vanadium-containing material is selected from the group consisting of soot, carbon, vanadium, vanadium oxide and mixtures thereof.
7. 7. A method according to claim 4, characterized in that the petroleum-based feedstock is selected from the group consisting of coke, oil and mixtures thereof.
8. 8. A method according to claim 1, characterized in that the controlled oxidation is carried out at a temperature ranging between approximately 1093 and 1371 ° C.
9. 9. A method according to claim 8, character! - bec the controlled oxidation temperature varies between approximately 1204 and 1260 β.
10. 10. A method according to claim 4, characterized in that a calcium-containing material selected from the group consisting of CaCO3, CaO and mixtures thereof during the partial oxidation is added to the petroleum-based feedstock.
11. 11. A method according to claim 1, characterized in that the oxidizing gas comprises oxygen.
12. 12. A method according to claim 1, characterized in that the weight ratio V203 / crystal varies between about 7: 1 and 3: 2, respectively.
13. 13. - A process for the production of synthesis gas, characterized in that it comprises: (a) adding an oxidizing gas containing free oxygen and a petroleum-based feedstock containing material that deposits slag to a reactor whose inner walls are coated with refractory material; (b) reacting the feed material and the oxidant gas containing free oxygen under partial oxidation conditions to produce synthesis gas containing hydrogen and carbon monoxide, and a slag byproduct comprising vanadium, mainly in the form of V203, and a siliceous glass material, wherein said synthesis gas leaves the reactor through an outlet for recovery, and wherein a portion of the slag accumulates in the walls of the reactor; (c) controlling the weight ratio V203 / crystal of the slag in the reactor during partial oxidation in an amount greater than 3: 2; and (d) replacing the partial oxidation conditions by controlled oxidation conditions in the reactor and increasing the partial pressure of the oxidizing gas to an amount sufficient to convert V203 to V205.
14. 14. A process according to claim 13, characterized in that the V203 content of the slag varies between approximately 60 and 80% by weight.
15. 15. A process according to claim 13, characterized in that the siliceous crystal content of the slag varies between approximately 20 and 30% by weight.
16. 16. A process according to claim 13, characterized in that a material containing vanadium is added to the petroleum-based feedstock in an amount ranging from 0.01 to 20% by weight approximately of the petroleum-based feedstock.
17. 17. A process according to claim 13, characterized in that the vanadium-containing material is selected from the group consisting of soot, carbon, vanadium, vanadium oxide and mixtures thereof.
18. 18. A process according to claim 13, characterized in that the petroleum-based feedstock is selected from the group consisting of coke, oil and mixtures thereof.
19. 19. A process according to claim 13, characterized in that the controlled oxidation is carried out at a temperature that varies between approximately 1093 and 1371 ° C.
20. 20. A process according to claim 13, characterized in that the controlled oxidation temperature varies between approximately 1204 and 1260 β.