Lining containers, composites, and methods

Abstract

A hydrocarbon conversion process is disclosed. The method introduces a feed stream comprising hydrocarbons into a vessel having a refractory liner. The refractory liner includes a refractory material and reinforcing metal fibers. The reinforcing metal fiber includes about 0.5 wt% to about 8 wt% aluminum, 10 wt% to about 35 wt% chromium, and no less than about 50 wt% iron. The hydrocarbons are converted in the vessel under conversion conditions with or without a catalyst to produce a production stream.

Description

TECHNICAL FIELD

[0001] This field relates to a method and apparatus for converting hydrocarbons. In particular, this field relates to a method for converting hydrocarbons in a vessel having a refractory lining. BACKGROUND OF THE INVENTION

[0002] Hydrocarbon conversion processes typically require reactor systems and associated conduits and piping suitable for hydrocracking, reforming, fluid catalytic cracking, and other similar processes. At the process conditions and temperatures required for hydrocarbon conversion, solid carbonaceous materials known as coke are typically formed on the metal alloy surfaces of reactor components and associated equipment due to metal-catalyzed reactions at the metal alloy surfaces. The formation of metal-catalyzed coke deposits is influenced by a variety of factors, such as the composition of the hydrocarbon feed, the conversion process, the specific reaction conditions, and the metallurgy and configuration of the reactor and associated equipment.

[0003] For many hydrocarbon processes in refining and petrochemical services, as commonly employed, metal-catalyzed coke deposits generally occur at appreciable rates from about 350 °C (662 °F) to about 850 °C (1562 °F). The formation of metal-catalyzed coke deposits for a particular process depends on the process conditions, the composition of the hydrocarbons involved, the composition of the metal surface in contact with the hydrocarbon stream, the time of contact between the metal and the hydrocarbon stream, and other similar considerations. The temperature at which a process will produce metal-catalyzed coke can be referred to as the metal-catalyzed coke onset temperature. If the process is operated at a temperature above the metal-catalyzed coke onset temperature, the accumulation of metal-catalyzed coke deposits can cause many significant problems within the reactor and associated equipment and can lead to severe heat transfer reduction, undesired pressure drop within the process, loss of process efficiency, and premature cessation of the conversion process. Thus, metal-catalyzed coke deposits can become severe enough to require premature cessation of the hydrocarbon conversion process to regenerate the catalyst and to decoke and replace the reactor and other surfaces vulnerable to coke deposits, as well as those components damaged by coking and associated reactions.

[0004] The metals that catalyze coke formation can reside on or within the catalyst, can be present on the process equipment, or can be present in the feed stream. Typical catalytic metals include: manganese, iron, cobalt, nickel, and chromium, among others. Such metals and their alloys are often used in hydrocarbon conversion reactors and associated equipment and thus often provide reaction sites for metal-catalyzed coke formation. For example, in the case where the reactor or associated component is of the austenitic stainless steel 300 series, the iron, chromium, and / or nickel metal alloys of the stainless steel provide sites and surfaces for the precipitation of metal-catalyzed coke to form under the operating conditions and temperatures used for hydrocarbon conversion processes.

[0005] Using a process temperature below the coke onset temperature catalyzed by metals can help reduce or eliminate metal-catalyzed coke formation, but using such reduced temperatures is often undesirable. Many hydrocarbon conversion processes require or benefit from temperatures approaching or exceeding the coke onset temperature to achieve efficient conversion rates and desired hydrocarbon conversion products and product mixtures. Approaches often used to reduce coke formation (such as using anti-fouling additives, radical scavengers, process equipment improvements to introduce turbulence and additional mixing, applying coatings to the interior of the process equipment, using higher grades of expensive metallurgy, or combining the metal alloys of the process equipment with anti-coking agents) have had limited success.

[0006] In some cases, sulfur or sulfur compounds are used to inhibit metal-catalyzed coke (MCC) formation at the surface of metal alloys in reactors and associated equipment. Introducing sulfur can increase the coke onset temperature and thus prevent metal-catalyzed coke at the operating temperature by raising the coke onset temperature above the operating temperature. However, sulfide corrosion of the metal can then become a problem. Such sulfur components used as metal-catalyzed coking inhibitors are typically introduced by adding them to the initial hydrocarbon stream and can be added during the conversion process. In cases where sulfur inhibitors are provided by addition, they are typically supplied by adding dimethyl sulfide (C2H6S) or dimethyl disulfide (DMDS) (C2H6S2) to the process stream, which then produces hydrogen sulfide (H2S) in the process stream. In such processes, typical concentration levels of H2S are generally from about 0.25 ppm to about 200 ppm by weight. At temperatures above about 350 °C (662 °F), due to the sulfidation reaction between H2S and the metal in the metal alloy surface, typical reactor materials (such as type 347 stainless steel) react corrosively with H2S in the hydrocarbon stream. Such corrosion of the metal alloy surface can substantially reduce the service life of reactor components and associated equipment, cause fouling, and interfere with the operation of the hydrocarbon conversion process.

[0007] MCC deposits of non-homogeneously catalyzed coke on the surfaces of reactors and equipment due to the presence of catalytic metals in the process metallurgy are common in hydrocarbon conversion processes (such as dehydrogenation), especially at temperatures above 350 °C. The increase in temperature causes the coking rate to increase exponentially. Olefin production processes (such as dehydrogenation processes with a large number of coke precursors, including olefins, dienes, and acetylene) have a high risk of coke formation, where the presence of coke precursors reduces the coke onset temperature. The problem of MCC deposit accumulation is well known. Reducing the process severity (e.g., temperature) can reduce or eliminate MCC, but is undesirable from the viewpoints of process economics and the need for efficient conversion rates and yields. This is especially true for olefin production processes, which often require temperatures close to 500 °C or 600 °C or higher for favorable economics.

[0008] The refractory compositions are recommended for use in various industries such as steelmaking, iron ore reduction, aluminum production, glass manufacturing, and hydrocarbon processing compatible with specific methods. An example is the use of basic magnesia refractories in steelmaking. In hydrocarbon processing, the main focus areas of refractories often have high abrasion resistance due to the high flow rate of abrasive catalysts and good adiabatic properties inside the reactors to conserve heat and provide a thermal gradient between the process-facing hot surface and the cold-wall pressure boundary housing of the refractory.

[0009] Hydrocarbon conversion processes often use iron or nickel and iron-based alloys as reactor materials, which can heterogeneously catalyze coke formation (such as metal-catalyzed coke), resulting in plugging, metal dusting, and corrosion, shortening the service life of the equipment at temperatures as low as 400 °C and above. Several measures (such as coating the reactor surface or using corrosion-resistant grades of reactor materials) and process variations (such as injecting anti-fouling agents or passivators (e.g., dimethyl disulfide) or reducing the reaction severity (such as temperature)) are often proposed to protect the reactor metallurgy. Less attention has been paid to refractory compositions for hydrocarbon processing.

[0010] In fluidized bed hydrocarbon processes, a refractory layer is typically applied to protect the metal wall from abrasion and provide good adiabatic properties. However, the presence of impurities (such as iron) in the refractory can catalyze MCC and cause the refractory to separate.

[0011] In some refractories, reinforcing fibers are used to provide resistance to crack propagation and increase the fracture thermal modulus, especially under thermal cycling in shaped refractories. Generally, reinforcing fibers from carbon steel to stainless steel in the 300 series are used at high temperatures and for increasing ductility. However, under harsh hydrocarbon processing conditions, such as in the reduction alkane dehydrogenation conditions at temperatures above 600 °C, the commonly recommended stainless steel 300 series fibers are vulnerable to coking and may crush the porous refractory into fragments, exposing the underlying internal components to further accelerated coking. In other cases, if the coking is too extreme, the refractory can peel off the wall and fall into the reactor, damaging the internal components. This is called "jacketing". In such cases, the damaged refractory can lead to the exposure of the underlying housing or internal substrate, resulting in some combination of corrosion, accelerated coking, and potential housing hotspots.

[0012] Ceramic or non-metallic reinforcing fibers have limitations such as general brittleness and difficulty in manufacturing due to fragmentation and surface cracking during mixing with abrasives (such as refractory matrices), which limits their application in refractories.

[0013] The petroleum industry is particularly interested in dehydrogenation processes because light hydrocarbons, such as butane, are low-value by-products from refining operations. Butane can be dehydrogenated to butene, which can then be used to produce MTBE. Additionally, propane can be dehydrogenated to produce propylene for use in plastics production.

[0014] Since hydrocarbon dehydrogenation is an endothermic reaction and the conversion level is limited by chemical equilibrium, it is desirable to operate at high temperatures and low pressures. High temperatures and low pressures shift the equilibrium favorably towards the dehydrogenation products. However, conventional dehydrogenation catalysts suffer rapid deactivation due to coking under these severe conditions. In particular, it has been found that the slow accumulation of carbon deposits reduces the dehydrogenation activity of conventional dehydrogenation catalysts. Therefore, conventional carbon burnout cycles are typically used to regenerate the catalyst system after sufficient carbon has accumulated on the catalyst. Additionally, sulfur compounds and hydrogen are typically introduced into the reactor feed to prevent carbon from accumulating in the reactor and on the catalyst.

[0015] Accordingly, there is a need for a method suitable for operating under highly severe conditions to mitigate refractory materials for MCC formation and carburization. SUMMARY OF THE INVENTION

[0016] The present disclosure provides a method and apparatus for processing hydrocarbons. The method includes introducing a feed stream into a container having a refractory lining that includes a refractory material and reinforcing metal fibers, the reinforcing metal fibers comprising from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. Processing the feed stream comprising hydrocarbons in the container. The apparatus for processing hydrocarbons includes a container having a refractory lining that includes a refractory material and reinforcing metal fibers, the reinforcing metal fibers comprising from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. Additionally, a composite material of a refractory material and reinforcing metal fibers is disclosed. The reinforcing metal fibers of the composite material comprise from about 0.5 wt% to about 8 wt% aluminum, from about 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an exemplary fluid catalytic cracking (FCC) unit according to an exemplary embodiment of the present disclosure.

[0018] Figure 2 is a cross-sectional schematic view of an exemplary riser reactor according to the present disclosure.

[0019] Figure 3 is from Figure 2 in the direction shown Figure 1 a cross-sectional schematic view of an exemplary riser reactor as viewed in perspective from line 2-2 of

[0020] Figure 4 is a cross-sectional schematic view showing a part of an exemplary riser reactor of the present disclosure.

[0021] Figure 5 Shows the test results of various refractory linings according to an exemplary embodiment of the present disclosure.

[0022] Definition

[0023] As used herein, the terms “vessel”, “reactor”, “process equipment”, “process unit” or “reactor component” shall include any process equipment and process unit used in a hydrocarbon conversion process and all process equipment and process units, which include any upstream equipment and / or downstream equipment from a particular unit and / or auxiliary equipment, such as furnace tubes, associated pipes, heat exchangers, heater tubes, etc. Detailed Description

[0024] Generally, when forming metal-catalyzed coking (MCC) in a reactor, the following steps can be carried out: chemisorbing a substance on the metal surface to form a metal-hydrocarbon complex on the metal microcrystals; decomposing the metal-hydrocarbon complex; carbon diffusion through the metal particles and deposition at the grain boundaries; the stress generated by the deposited carbon finally removes the metal microcrystals, and carbon filaments grow from the surface having metal microcrystals at the tips. Here, the carbon diffusion through the metal microcrystals can be regarded as the rate-determining step.

[0025] The present disclosure provides a refractory lining for a vessel, which includes a refractory material and reinforcing metal fibers, and the refractory lining can be used in high-temperature and high-severity hydrocarbon conversion applications that are becoming more relevant in the modern petrochemical industry. Any hydrocarbon process that requires a refractory lining to protect the base metallurgy of the vessel under any process conditions (such as oxidation or reduction or a combination of both) and any process configuration (such as fixed bed, moving bed and fluidized bed, where any part of the reactor operates at 500 °C or above) can benefit from the refractory lining of the present disclosure to mitigate coking, especially MCC.

[0026] It has been reported that the formation of MCC filaments further promotes non-catalytic heterogeneous coke deposition and coking reactions. The embrittlement of the reactor metallurgy due to carburization (where carbon diffuses from the process stream into the grain boundaries) forms metal carbides. The formation of metal carbides causes the release of metal dusting, catalytically active particles and metal droplets, and the catalytically active particles and metal droplets can further catalyze coke formation in other areas where they are deposited throughout the process.

[0027] In one aspect of the present disclosure, the refractory lining can be used in various processes, including but not limited to steam reforming of hydrocarbons to produce hydrogen and carbon monoxide, hydrocracking, hydrotreating, isomerization, reforming, fluid catalytic cracking, catalytic naphtha cracking, steam cracking, dehydrogenation including using an ion conductor membrane, fluid catalytic dehydrogenation, catalytic dehydroalkylation, thermal dehydroalkylation, toluene methylation, methanol to gasoline (MTG), methanol to olefins (MTO), partial oxidation reforming, autothermal reforming of methane and higher hydrocarbons. The lining is particularly suitable for reactor vessels for producing olefins.

[0028] The refractory lining of the present disclosure comprises reinforcing metal fibers dispersed throughout the refractory matrix. When used in hydrocarbon processing applications, the reinforcing metal fibers in the refractory lining provide improved resistance to carburization against MCC and reduce coke formation. The present disclosure provides an appropriate grade of reinforcing fibers for use in refractories for demanding hydrocarbon processing applications, with the aim of improving resistance to carburization and reducing coke formation by MCC. In particular, the present disclosure addresses the problem of MCC for refractories (including fibers used in refractories under gaseous hydrocarbon conversion processes). The disclosed refractory lining with reinforcing metal fibers reduces coke formation under hydrocarbon conversion processes and improves the durability of the refractory lining on the vessel. The highly carburization-resistant refractory lining of the present disclosure functions for a longer time under process conditions without decomposing due to coking on the embedded fibers.

[0029] The reinforcing fibers embedded in the porous refractory are exposed to fluidized coke precursors in the process, which can diffuse in the vessel, and the presence of cracks or gaps in the refractory can cause the formation of dead zones in the vessel (such as a reactor), and these dead zones can exponentially increase coke formation due to significantly low or zero space velocity areas. In the refractory lining of the present disclosure, the reinforcing metal fibers are not only carburization-resistant but also provide the general protection of fiber reinforcement provided by stainless steel to the refractory, such as minimizing crack propagation and increasing ductility and thermal cycling resistance. The improved refractory durability under demanding conditions enables hydrocarbon conversion processes to operate at a given higher severity to provide higher yields or conversions.

[0030] The present disclosure discloses introducing a feed stream containing hydrocarbons into a vessel having a refractory lining, which includes a refractory material and reinforcing metal fibers, that provides resistance to carburization and coking in hydrocarbon conversion processes that require insulation and / or abrasion resistance of the vessel wall. In cases where the vessel wall has process fluids on both sides, such as in a fluid catalytic riser, the refractory lining can be applied to both sides of the vessel or the pipe wall. The vessel includes a reactor and its surface, reactor components, pipes, heat exchangers, heater tubes, associated piping, and the like.

[0031] Impurities in the refractory (such as iron) can catalyze the MCC. Although the present disclosure is not limited to the specific composition of the refractory, the refractory must have a low inherent coking potential under the process conditions. Some examples of refractory manufacturers include: Calderys, Harbison-Walker Refractories, Morgan Thermal Ceramics, AGC Plibrico Co., Ltd., Resco Products, Stellar Materials, RHI Refractories, and Vesuvius Refractories International, Inc. In an exemplary embodiment, the refractory is the Thermbond 2125 refractory from Stellar Materials, which has a high content of alumina and silica, phosphate, and a low iron content. The composition of Thermbond 2125 can be as shown in Table 1 below:

[0032] Table 1

[0033]

[0034] The refractory lining of the present disclosure can be applied to any type of reactor, including fixed-bed reactors, moving-bed reactors, and fluidized-bed reactors, which can operate at a temperature of 400 °C or higher. The refractory lining of the present disclosure can be used in hydrocarbon conversion processes operating in oxidative, reductive, or combined environments. In addition, the refractory lining of the present disclosure can be supported by an anchoring support system (such as V-shaped anchors, S-shaped bars, etc.), which can be attached to the inner surface of the container wall to support the refractory lining on the wall. The container wall is typically metal. The refractory lining of the present disclosure provides thermal insulation and / or abrasion resistance for the container or equipment to which it is applied. In one aspect, the refractory lining of the present disclosure provides thermal insulation for the container or equipment to which it is applied.

[0035] In another embodiment of the present disclosure, a composite material is disclosed, which composite material comprises a refractory material and reinforcing metal fibers. In one embodiment, the refractory material comprises no more than about 3.5 wt% iron oxide and at least about 33 wt% alumina. The reinforcing metal fibers may comprise from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. In one aspect, the reinforcing metal fibers comprise no more than about 17 wt% chromium. In another aspect, the reinforcing metal fibers comprise at least 2 wt% aluminum and no more than 18 wt% chromium.

[0036] The composite material may include any suitable refractory material that provides thermal insulation and / or abrasion resistance. In one embodiment, the refractory material may be characterized by a refractory density of from about 1120 kg / m 3 to about 2320 kg / m 3 . In another embodiment, the refractory material may be characterized by a cold crushing strength of at least 42 kg / m 2 .

[0037] In one exemplary embodiment, the composite material may comprise from about 1 wt% to about 10 wt% of the reinforcing metal fibers. In another exemplary embodiment, the reinforcing metal fibers are oxidized metal fibers.

[0038] According to an embodiment of the present disclosure, a hydrocarbon conversion method is disclosed. The method includes introducing a feed stream comprising hydrocarbons into a container having a refractory lining. In one exemplary embodiment, the refractory lining includes: a refractory material and reinforcing metal fibers, the reinforcing metal fibers comprising from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. In another exemplary embodiment, the reinforcing metal fibers may comprise at least 2 wt% aluminum and no more than about 18 wt% chromium. The hydrocarbons may be processed in the container under conditions in which they are present. Further, the hydrocarbons may be converted in the container under conversion conditions with or without a catalyst to produce a product stream. In one aspect of the present disclosure, the product stream may comprise olefins. In another aspect of the present disclosure, the method is a fluid catalytic method, which fluid catalytic method includes a propane dehydrogenation (PDH) method, a toluene methylation method, a catalytic naphtha cracking method, and a fluid catalytic cracking (FCC) method.

[0039] Aluminum is an element used to improve the carburization resistance of stainless steel because it forms a stable alumina layer on the surface of the metal fibers, which alumina layer improves the coke formation resistance. To ensure acceptable carburization resistance, from about 0.5 wt% to about 8 wt% aluminum may be used, while aluminum above about 8 wt% may reduce the toughness of the steel. In an exemplary embodiment of the present disclosure, the reinforcing metal fibers may comprise not less than about 13 wt% chromium.

[0040] In another exemplary embodiment of the present disclosure, the inner refractory lining comprises from about 1 wt% to about 10 wt% of reinforcing metal fibers.

[0041] Depending on the application, the reinforcing metal fibers can have any suitable shape and / or size. The fibers are preferably helical, wavy, and / or corrugated to increase the surface area and improve adhesion to the refractory. Optionally, the reinforcing metal fibers can be oxidized in air at an elevated temperature prior to incorporation into the refractory for increased coking mitigation. In one exemplary embodiment, the reinforcing metal fibers can be oxidized in dry air at a temperature of about 600 °C to about 800 °C to provide oxidized metal fibers. In one aspect, the inner refractory lining can comprise oxidized metal fibers.

[0042] In another aspect of the present disclosure, the reinforcing metal fibers can be oxidized in situ. According to the present disclosure, the reinforcing metal fibers can be oxidized in situ during the drying process of the refractory material in the process unit. The drying process is typically a staged process that heats from ambient temperature to the process temperature under an air flow typically at the start of the process.

[0043] The refractory lining can also comprise a minor alloying component in an amount of about 1 wt%. In one embodiment, the reinforcing metal fibers can comprise each of one or more of carbon, silicon, manganese, sulfur, and phosphorus in an amount of less than about 1 wt%.

[0044] In addition, the refractory lining can comprise some optional components. In one embodiment, the reinforcing metal fibers can comprise less than about 20 wt% of molybdenum, less than a total of about 5 wt% of one or more of cobalt, yttrium, niobium, and copper, less than about 1 wt% of titanium, and less than about 1 wt% of lanthanide elements.

[0045] According to one aspect of the present disclosure, the hydrocarbon conversion is a fluid catalytic cracking (FCC) process. The FCC process is well known for converting relatively high-boiling hydrocarbons into lighter hydrocarbons. In many catalytic cracking reactors (often referred to as riser reactors, risers, or tubular reactors), long-chain hydrocarbon feeds are cracked on a catalyst to produce shorter-chain products. This can be referred to as the cracked feed. The feed and the fluidized catalyst are introduced into a vertical riser at the lower inlet and travel vertically upward within the riser, where the feed and the fluidized catalyst react at a very high temperature until they reach the upper outlet.

[0046] Figure 1An exemplary FCC unit 101 is shown that includes a reactor riser 112 and a catalyst regenerator 118. For purposes of clarity and brevity, the FCC unit 101 has been schematically illustrated and does not include elements that are not important to the consideration of the present disclosure. In the reactor riser 112, a hydrocarbon feedstock contacts a fluidized catalyst stream through a distributor 113 or a plurality of distributors near the bottom of the reactor riser 112. The hydrocarbon feedstock evaporates and is converted or cracked into cracked products. Conditions in the reactor riser 112 can include a cracking reaction temperature of from about 400 °C to about 700 °C, preferably from about 565 °C to about 600 °C at the reactor outlet. The cracking occurs at an absolute pressure between about 100 kPa (14 psia) and about 506 kPa (74 psia), preferably between about 138 kPa (20 psia) and about 310 kPa (45 psia).

[0047] Spent catalyst is withdrawn and conveyed to the catalyst regenerator 118 through a spent catalyst line 114. In the catalyst regenerator 118, coke is burned from the spent catalyst in a combustion chamber to provide regenerated catalyst. The regenerated catalyst is conveyed to the reactor riser 112 through a regenerated catalyst line 116 where it is mixed with the introduced hydrocarbon feedstock.

[0048] The reaction efficiency in the riser depends on factors such as good and uniform mixing between the feedstock and the fluidized catalyst. It is desirable for the feed to be evenly dispersed in the fluidized catalyst stream moving upward along the riser. However, in many risers, even if near-uniform dispersion is achieved at the riser inlet, non-uniform mixing can occur as the material travels upward, due at least in part to non-uniform cross-sectional gas velocities caused by temperature differences and other factors. In one embodiment of the present disclosure, a continuous refractory lining can be attached to the inner surface and / or the outer surface of the riser wall to minimize heat loss and resist erosion and corrosion.

[0049] Figure 2 The present disclosure is schematically illustrated Figure 1Vertical cross-section of the exemplary riser reactor 112 shown. For purposes of clarity and conciseness, the riser reactor 112 has been schematically illustrated, where elements not important to the present disclosure have been excluded. The riser reactor 112 can be, for example, a catalytic cracking reactor for converting relatively long-chain hydrocarbons into shorter-chain products. The riser reactor 112 is generally cylindrical and can be referred to as a tubular reactor. The riser reactor is vertically lifted, where the feedstock (flow direction generally indicated by arrow 11) and the catalyst (generally indicated by arrow 15) are fed into the interior 12 of the reactor at the lower inlet 14. The catalyst and the feedstock contact each other, and the feedstock reacts as they flow vertically through the riser reactor 112, and the product is removed at the upper outlet 16. The feedstock can be fluidized in the flowing catalyst.

[0050] The riser reactor 112 includes a generally cylindrical sidewall 18 that circumferentially surrounds the interior 12 and extends from the inlet 14 to the outlet 16, having a refractory lining 20 on the interior of the wall 18. The wall is made of metal (such as steel). However, the refractory lining can be located on two surfaces (the interior surface and the exterior surface) of the riser reactor 112, especially when the riser is within another vessel. The lining 20 provides heat resistance and abrasion resistance and can extend over all or part of the operating length of the riser reactor 112 between the inlet 14 and the outlet 16. The riser reactor 112 can operate at high temperatures or even extremely high temperatures and also includes flowing reactive catalyst. These factors and other factors can result in a highly corrosive environment. In addition, minimizing heat loss, minimizing the temperature of the wall 18, and maintaining the desired temperature in the interior 12 of the reactor may be important for operating reasons. The refractory lining 20 is useful for addressing these and other considerations.

[0051] In one aspect, the entire refractory lining 20 is continuous, or at least most of it is continuous. As used herein, the term "continuous" is intended to broadly refer to a condition where there are substantially no seams or other breaks in the construction.

[0052] The refractory lining 20 has an interior surface 22 that is generally parallel to the wall 18. The thickness of the refractory lining between the interior surface 22 and the wall 18 can vary depending on the application and other factors, but in many applications this thickness will be between about 1.905 cm (3 / 4 inch) and about 20.32 cm (8 inches). In some catalytic cracking reactors, a thickness of about 7.6 cm (3 inches) to about 12.7 cm (5 inches) may be useful.

[0053] Figure 3 is a perspective view as viewed in the direction indicated by the arrow from line 2-2 Figure 2 of the same riser reactor 112 in a top plan cross-sectional view.

[0054] Figure 4 shows a more detailed cross-section of a portion of the riser reactor 112 (flow direction along the general direction of the arrow) defined between the dashed lines 3-3 in Figure 2 . The riser reactor 112 includes a plurality of V-shaped anchors 47, where a refractory 42 is cast on the wall and supported on the wall 18 by the anchors 47.

[0055] The V-shaped anchors 47 can be welded to the wall 18 to enhance adhesion to the wall and the mechanical integrity of the refractory lining 20. The V-shaped anchors 47 can be made of metal or other materials, one example being 310 stainless steel. The V-shaped anchors 47 can be welded to the wall 18 and are completely surrounded by the refractory 42 as indicated in the figure. The V-shape that is wider the farther away from the wall 18 is used to attach the refractory lining 20 to the wall. It should be understood that a variety of anchor 47 configurations can be used.

[0056] Suitable materials for the refractory 42 are those that provide good thermal insulation and / or abrasion resistance. Many materials are castable. A variety of suitable materials are known, including standard Portland cement and many more highly engineered materials. Many (but not all) refractories are inorganic, non-metallic, porous, and inhomogeneous materials that contain thermally stable mineral aggregates, binder phases, and one or more additives. They can include one or more of silica, alumina, calcium oxide, titanium oxide, iron oxide, magnesia, zircon, and others. For different applications, different compositions can be selected, where design considerations include the degree of required heat resistance and / or abrasion resistance. Examples include higher abrasion-resistant refractories in lining portions that may be significantly affected by wear.

[0057] Example lightweight commercial refractory products include, but are not limited to, refractory products having: an iron oxide content of less than about 3.5% (by weight) and an alumina greater than about 33% (by weight); a working temperature rating of at least 1315 °C (2400 °F); a density of about 1120 kg / m 3 (70 lb / ft 3 ) to about 1440 kg / m3 (90 lb / ft 3 )(as measured using the ASTM C 134 test procedure); a cold crushing strength of at least 42 kg / m 2 (600 psi) (as measured using the ASTM C 133 test procedure) after heating to 815 °C (1500 °F) and cooling to ambient temperature; and an average thermal conductivity of about 0.35 W / m °C (2.30 BTU-in / ft 2-h-°F) to about 0.45 W / m°C (3.00 BTU-in / ft 2 -h-°F).

[0058] Examples of commercially available refractory products include, but are not limited to, refractory products having the following: an iron oxide content of less than 1.0% (by weight) and an alumina greater than 35% (by weight); a working temperature rating of at least 1315°C (2400°F); a density of about 1600 kg / m 3 (100 lb / ft 3 ) to about 2320 kg / m 3 (145 lb / ft 3 )(as measured using ASTM C 134 test procedure); a cold crushing strength of at least about 420 kg / m 2 (6000 psi) (as measured using ASTM C 133 test procedure) after heating to 815°C (1500°F) and cooling to ambient temperature; and a thermal conductivity between about 0.75 W / m°C (5.3 BTU-in / ft 2 -h-°F) and about 1.45 W / m°C (10.0 BTU-in / ft 2 -h-°F) at an average temperature of 540°C (1000°F).

[0059] Examples of high abrasion resistant products having a relatively high abrasion resistance may include (but are not limited to) refractory products having the following: an iron oxide content of less than 1.0% (by weight) and an alumina greater than 80% (by weight); a working temperature rating of at least 1260°C (2300°F); a density of at least 2480 kg / m3 (155 lb / ft3) (as measured using ASTM C 134 test procedure) after heating to 815°C (1500°F) and cooling to ambient temperature; a cold crushing strength of at least 845 kg / m2 (12,000 psi) (as measured using ASTM C 133 test procedure) after heating to 815°C (1500°F) and cooling to ambient temperature.

[0060] In one aspect, the melt-spun metal fibers are used with the refractory. In particular, melt-spun metal fibers produced using the melt extraction (ME) method or the melt overflow (MO) method are used. In the ME method, a rotating water-cooled copper drum having a structured surface is immersed in molten metal (e.g., stainless steel), and the copper drum centrifugally throws the molten material out of the crucible. In this method, the molten material is solidified and collected in the form of fibers. The fibers obtained using the ME method may have a diameter of, for example, 500 μm at a length of about 20 mm.

[0061] In the MO process, a rotating water-cooled copper drum is arranged below an opening in a crucible containing molten material, and the molten material is slowly poured onto the rotating drum. MO fibers can be made much finer than ME fibers, and the fibers obtained using the MO process are long fibers that can be used, for example, in fabrics. MO fibers are sickle-shaped in cross-section.

[0062] To produce a refractory lining, first, reinforcing metal fibers are gradually mixed into the refractory material in a mixer until the desired amount of reinforcing metal fibers has been added. Then, mixing is continued until the mixture is homogeneous, after which a dry carbon carrier, such as graphite or soot, is added. Then, the coarser parts of the refractory material can be gradually mixed into this premix until all of the refractory material is homogeneously mixed with the reinforcing metal fibers and graphite. If a resin-bonded molded body / panel is to be produced, the resin is added to a cold mixer and mixed until the mixture is homogeneous. If a resin / hardener mixture is used, the resin is premixed with the hardener, and the two components are added together, or alternatively, first only the resin is added, and then the hardener is added, in each case mixing until the mixture is homogeneous. Additionally, the mixture of refractory material, reinforcing metal fibers, and carbon can be placed in a separate dedicated mixer to be mixed with the resin or binder, where the mixing with the resin takes place. Additionally, if desired, the batch also contains antioxidants and other commonly used ingredients, such as pressing aids (if required).

[0063] The final batch mixture can be fed into a press commonly used in the refractory industry, where the final batch mixture is pressed into a molded body, for example, using a pressure of 180 N / mm 2 of pressure.

[0064] Then, at a temperature between 120 °C and 200 °C, the final resin-bonded molded body / panel is subjected to the hardening step conventional in the art.

[0065] Then, the molded body / panel produced in the above manner is assembled in place in a container.

[0066] According to another aspect of the present disclosure, an apparatus for converting hydrocarbons is disclosed. The apparatus includes a container having the refractory lining of the present disclosure, the refractory lining including a refractory material and reinforcing metal fibers, the reinforcing metal fibers comprising 20 wt% to about 35 wt% chromium and not less than about 50 wt% iron. In another aspect, the reinforcing metal fibers can comprise about 0.5 wt% to about 8 wt% aluminum, 10 wt% to about 35 wt% chromium, and not less than about 50 wt% iron. In yet another aspect, the reinforcing metal fibers can comprise at least 2 wt% aluminum and less than 18 wt% chromium.

[0067] Example

[0068] A test apparatus is used that allows for parallel rapid screening of several samples. The test apparatus includes several quartz reactors with frits on which the samples are placed, and the quartz reactors are connected to a common inlet gas manifold to simulate the same reaction conditions in parallel across all samples. After placing the samples inside the reactors, under a flow of inert gas, the temperature is raised to 630 °C, and at the target temperature, the feed is switched to a gas mixture of hydrogen:propane:propylene (molar ratio) of 1:1:1, at a temperature of 630 °C, and with a total MAPD (methylacetylene, acetylene, and allene) content of approximately 470 ppm. S is not used in the test. At the end of the test cycle, the samples are cooled to room temperature under a flow of inert gas, then the samples are removed and further analyzed. Before and after each test, the sample weights are carefully recorded, and the difference in weights is recorded as coke deposition during the test. The observations and test results are discussed below.

[0069] Example 1

[0070] Commercial standard SS-304 metal fibers are tested together with the metal fibers of the present disclosure. The compositions of the fibers tested are shown in Table 2 below:

[0071] Table 2

[0072]

[0073]

[0074] Commercial standard stainless steel 304 (SS-304) fibers are used for comparative analysis as a baseline. A, B, and C include the aluminum-containing fibers of the present disclosure.

[0075] The weight gain of the bare fibers is tested, and this weight gain represents coke deposits. The bare fibers are exposed to the following method conditions:

[0076] Feed (molar ratio) = 1:1:1 (H2:C3:C3=), sulfur-free, and 470 ppm of methylacetylene-acetylene-allene (MAPD); temperature of 630 °C, and time of 8 days.

[0077] The results are shown in Table 3 below:

[0078] Table 3

[0079]

[0080] The SS-304 results represent the average of two commercially available stainless steel 304 (SS-304) fibers. Visually, much higher coke deposits were observed on the SS-304 fibers after testing compared to the aluminum-containing fibers of the present disclosure. The quantitative results shown in Table 3 confirm the qualitative visual observations, where the weight gain of the aluminum-containing fibers of the present disclosure was significantly lower than that of the commercially available stainless steel SS-304 fibers when the bare fibers were exposed to the method conditions. This highlights the low coking potential of the bare aluminum-containing fibers when compared to standard SS-304 fibers used in hydrocarbon processing.

[0081] Example 2

[0082] The aluminum-containing fibers of the present disclosure were cast into sample blocks with Thermbond 2125 refractory to test the expected performance relative to refractory samples embedded with commercially standard SS-304 fibers under the above method conditions. The formed green cast blocks were broken into smaller fragments by crumbling, and these blocks were selected for testing, which had at least one exposed fiber on the surface. These method conditions were similar to those used in Example 1 above. The results are shown in Table 4 below:

[0083] Table 4

[0084]

[0085] As shown in Table 4, for the refractory with the aluminum-containing fibers of the present disclosure, the weight gain was significantly minimal on average compared to the refractory with commercially standard SS-304 fibers.

[0086] After 8 days of exposure to the method conditions, the SS-304-containing refractory cracked due to coke deposition on the fibers, as Figure 5 shown. S1 shows the Thermbond 2125 refractory embedded with SS-304 fibers before testing, and S2 shows the Thermbond 2125 refractory embedded with SS-304 fibers after testing. In Figure 5 , S3 shows the higher coke deposition on the cracked Thermbond 2125 refractory embedded with SS-304 fibers. However, for the refractory with the aluminum-containing fibers of the present disclosure, the integrity of the sample was maintained.

[0087] In Figure 5A comparison of photographs of refractory blocks that were fractured before and after testing is shown. A1 shows the Thermobond 2125 refractory embedded with fiber A before testing and A2 shows the Thermobond 2125 refractory embedded with fiber A after testing, B1 shows the Thermobond 2125 refractory embedded with fiber B before testing and B2 shows the Thermobond 2125 refractory embedded with fiber B after testing, and C1 shows the Thermobond 2125 refractory embedded with fiber C before testing and C2 shows the Thermobond 2125 refractory embedded with fiber C after testing. As Figure 5 shown, the Thermobond 2125 refractories embedded with fibers A, B, and C maintained their integrity after being tested under the method conditions. These results confirm that, compared with standard SS-304 fibers, under these method conditions, minimal coke formation occurred on the fragmented refractory pieces reinforced with the aluminum-containing fibers of the present disclosure, and even with exposed fibers, these fragmented refractory pieces maintained their integrity after 8 days of continuous testing. Thus, the incorporation of the aluminum-containing fibers enhanced the resistance of the entire refractory lining to MCC and contributed to maintaining the integrity of the refractory under harsh method conditions, thereby extending the operating life of the unit.

[0088] Example 3

[0089] The aluminum-containing fibers of the present disclosure were oxidized for 8 hours under a stream of air at 750 °C. Both the oxidized bare fibers and the unoxidized bare fibers were tested under method conditions similar to those of Examples 1 and 2. The results are shown in Table 5 below:

[0090] Table 5

[0091]

[0092] The results show that the aluminum-containing fibers of the present disclosure performed significantly better than commercially available standard SS-304 fibers in terms of coke reduction. In addition, the oxidized aluminum-containing fibers of the present disclosure showed a significant improvement in coke reduction compared with the unoxidized fibers, further improving the resistance to MCC formation.

[0093] Specific implementation

[0094] Although the following is described in connection with specific embodiments, it should be understood that the description is intended to illustrate and not limit the scope of the foregoing description and the appended claims.

[0095] A first embodiment of the present disclosure is a hydrocarbon conversion process, the hydrocarbon conversion process comprising: introducing a feed stream comprising hydrocarbons into a vessel having a refractory lining, the refractory lining comprising a refractory material; and reinforcing metal fibers, the reinforcing metal fibers comprising from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and greater than about 50 wt% iron; and converting the hydrocarbons in the vessel under conversion conditions with or without a catalyst to produce a product stream. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise less than 1 wt% nickel. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise at least 2 wt% aluminum. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the refractory lining comprises from about 1 wt% to about 10 wt% reinforcing metal fibers. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the product stream comprises olefins. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers are oxidized metal fibers. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise less than about 1 wt% of one or more of carbon, silicon, manganese, sulfur, and phosphorus each. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the refractory lining is supported by anchors attached to the inner wall of the vessel. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the catalyst is a fluidized catalyst. An embodiment of the present disclosure is one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise less than about 20 wt% molybdenum, in total less than about 5 wt% of about one or more of cobalt, yttrium, niobium, and copper, less than about 1 wt% titanium, and less than about 1 wt% lanthanides.

[0096] A second embodiment of the present disclosure is a composite material comprising a refractory material comprising no more than about 3.5 wt% iron oxide and at least about 33 wt% alumina; and reinforcing metal fibers comprising from 0.1 wt% to about 35 wt% chromium and greater than about 50 wt% iron. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, having a refractory density of about 1120 kg / m 3 to about 2320 kg / m 3 . Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, having a refractory cold crushing strength of at least 42 kg / m 2 . Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise at least 2 wt% aluminum and less than 18 wt% chromium. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise less than 1 wt% nickel. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the refractory lining comprises from about 1 wt% to about 10 wt% reinforcing metal fibers. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers are oxidized metal fibers. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph to the first embodiment in this paragraph, wherein the reinforcing metal fibers comprise from about 0.5 wt% to 8 wt% aluminum.

[0097] A third embodiment of the present disclosure is an apparatus for converting hydrocarbons, the apparatus comprising a vessel having a refractory lining, the refractory lining comprising a refractory material; and reinforcing metal fibers, the reinforcing metal fibers comprising from about 0.5 wt% to about 8 wt% aluminum, from 10 wt% to about 35 wt% chromium, and greater than about 50 wt% iron. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph through the third embodiment in this paragraph, wherein the refractory lining is supported by a plurality of anchor members attached to the inner wall of the vessel. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph through the third embodiment in this paragraph, wherein the reinforcing metal fibers comprise at least 2 wt% aluminum. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph through the third embodiment in this paragraph, wherein the refractory lining comprises from about 1 wt% to about 10 wt% reinforcing metal fibers. Embodiments of the present disclosure are one, any, or all of the previous embodiments in this paragraph through the third embodiment in this paragraph, wherein the reinforcing metal fibers are oxidized metal fibers.

[0098] Although no further detailed description is provided, it is believed that those skilled in the art can make the most of the present disclosure by using the foregoing description and can easily determine the basic features of the present disclosure without departing from the spirit and scope of the invention, and various changes and modifications of the present disclosure can be made and adapted to various uses and conditions. Accordingly, the foregoing preferred specific embodiments should be construed as illustrative only and in no way limiting the remainder of the present disclosure, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0099] In the foregoing, all temperatures are shown in degrees Celsius and all parts and percentages are by weight unless otherwise indicated.

Claims

1. A hydrocarbon conversion method, comprising: A feed stream comprising hydrocarbons is introduced into a vessel having a refractory lining comprising: Refractory materials; and The reinforcing metal fiber comprises about 0.5 wt % to about 8 % by weight aluminum, from about 10% by weight to about 35% by weight chromium, and not less than about 50% by weight iron; and The hydrocarbons in the vessel are processed under the conditions existing in the vessel.

2. The method of claim 1, wherein the reinforcing metal fibers contain less than 1 wt. % nickel.

3. The method of claim 1, wherein the reinforcing metal fibers comprise at least 2 wt% aluminum, no greater than about 18 wt% chromium.

4. The method of claim 1 wherein the refractory lining comprises from about 1 wt% to about 10 wt% reinforcing metal fibers.

5. The method according to claim 1, further comprising: A product stream is produced from the vessel, wherein the product stream comprises olefins.

6. A composite material, comprising: a refractory material comprising no greater than about 3.5 weight percent iron oxide and at least about 33 weight percent aluminum oxide; and A reinforcing metal fiber comprising from about 0.5 wt % to about 8 wt % aluminum, from 10 wt % to about 35 wt % chromium, and not less than about 50 wt % iron.

7. The composite material of claim 6, wherein the reinforcing metal fibers comprise not greater than about 18 wt. % chromium.

8. The composite material of claim 6, wherein the composite material has a relative humidity of about 1120 kg / m 3 About 2320kg / m 3 Refractory density.

9. The composite material according to claim 6, wherein the composite material has a strength of at least 42 kg / m 2 Refractory cold crushing strength.

10. An apparatus for processing hydrocarbons, the apparatus for processing hydrocarbons comprising: A container having a refractory lining, the refractory lining comprising: Refractory materials; and A reinforcing metal fiber comprising from about 0.5 wt % to about 8 wt % aluminum, from 10 wt % to about 35 wt % chromium, and greater than about 50 wt % iron.

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