Patent Application
20240059568
The present disclosure relates to an apparatus, a process and a system for treating petroleum coke, in particular to an apparatus, a process and a system for preparing porous carbon materials by using petroleum coke as raw materials.
Petroleum coke is a product of delayed coking unit. It has properties such as high calorific value, high moisture, low volatiles, and the like. It is obtained in a yield of about 25%-30% of the feedstock oils added to the coking unit. Along with the further development of delayed coking technology, how to effectively utilize petroleum coke and improve its added value are difficulties facing the industry at present. Use of petroleum coke as raw materials for preparing porous carbon materials is one of the effective ways to increase the value of petroleum coke in recent years.
Porous carbon materials derived from petroleum coke have properties such as low impurity content, high specific surface area, stable physical and chemical properties, and the like. They are widely used in fields such as industry, agriculture, national defense, science and technology, and the like. Compared with raw materials such as biomass, coal, asphalt and the like, petroleum coke is graphitized to a higher degree and thereby relatively difficult to be activated. The activation of petroleum coke generally requires alkali metal hydroxide such as potassium hydroxide and the like as an activator. During the activation, there are problems such as serious corrosions of equipment, unstable properties of products, and the like.
U.S. Pat. No. 4,082,694A discloses an activated carbon and a process for preparing the same. The process comprises: stirring and heating a feed of pulverized coal, coal coke, petroleum coke or mixture thereof in the presence of a considerable weight ratio of aqueous potassium hydroxide at a first and lower temperature to dehydrate the feed; activating the dehydrated feed by heating to a second and higher temperature; then cooling and removing inorganic materials therefrom by washing, to form activated carbon with higher specific surface area. The prepared activated carbon has a cage-like structure, microporosity, and good bulk density and total organic carbon index. For example, the process for preparing may comprise the steps of: mixing petroleum coke with potassium hydroxide at three times by weight, dehydrating at a temperature of 300-500° C., activating at a temperature of 700-800° C., and subjecting the activated mixture to washing by water, to produce activated carbon with a specific surface area of 2600 m2/g.
JP95-215711 discloses a method for activating petroleum coke with potassium hydroxide at three times by weight at 800° C. and a reduced pressure to produce activated carbon with a specific surface area of 3000 m2/g or greater, wherein a tunnel kiln activation furnace is used.
CN1304788A prepares an activated carbon with a specific surface area of 3500 m2/g or greater by mixing KOH and petroleum coke at a weight ratio of 5:1, and activating at high temperature.
At present, the prior art processes for activating petroleum coke adopt relatively high ratio of the base to the petroleum coke, which may result in serious corrosion of the activation equipment. In general, rotary kilns or tunnel kilns are used as the devices for activating petroleum coke with a base. When a rotary kiln is used in high-temperature activation, due to the physical state of the materials therein changing with temperature, some of the materials may be liquefied and adhere to the wall of the rotary kiln reactor during the rotation, forming a dense material layer that may adversely affect heat transfer and cause uneven heating of the materials, thereby affecting the activation and leading to unstable properties of products. When a tunnel kiln is used, the feed is transported on a conveyor belt. It is activated at high temperature while passing through the tunnel kiln. Tunnel kilns usually use long flexible conveyor belts and support structures. Under high temperature and alkali conditions during the activation, the conveyor belt and its support structure easily suffer from structural collapsing and corrosion, leading to abnormal operation of the activation equipment. Although the industrial production of activated carbon from petroleum coke has been realized now, there are still problems such as high cost for activators and unstable properties of products. Therefore, there is still a demand for further developing processes, apparatuses and systems for preparing porous carbon materials from petroleum coke.
The present disclosure is to provide a process, an apparatus and a system for treating petroleum coke to overcome the disadvantages of the prior art. The process, apparatus and system in accordance with the present disclosure can achieve continuous production, and have advantages of high activation efficiency and stable properties of the obtained carbon material products.
In the first aspect, provided in the present disclosure is a process for treating petroleum coke, comprising the steps of:
Preferably, the process for treating petroleum coke further comprises the step of:
Further preferably, the process for treating petroleum coke further comprises the step of:
In the process for treating petroleum coke in accordance with the present disclosure, the feed of petroleum coke may be preferably subjected to drying and pulverizing before being added together with the activator into the first reactor in step (1). The drying may be operated according to well-known methods in the art. Generally, the dried feed of petroleum coke may have a water content of not more than 2 wt %, preferably not more than 1 wt %. The pulverizing may be operated according to well-known methods in the art. The pulverized feed of petroleum coke may have a particle size of not greater than 200 μm, preferably not greater than 150 μm.
In the process for treating petroleum coke in accordance with the present disclosure, the first treatment in step (1) may be operated at a temperature of 200-500° C., preferably 350-450° C.
In the process for treating petroleum coke in accordance with the present disclosure, the activator and the feed of petroleum coke in step (1) may be in a mass ratio of 0.5:1-8:1, preferably 1:1-5:1.
In the process for treating petroleum coke in accordance with the present disclosure, the activator in step (1) may be an alkali metal compound, preferably one or more selected from the group consisting of potassium hydroxide, sodium hydroxide, potassium carbonate and sodium carbonate, more preferably a mixture of one or two of potassium hydroxide and sodium hydroxide with one or two of potassium carbonate and sodium carbonate, and most preferably a mixture of potassium hydroxide and potassium carbonate. In one variant, the mixture of potassium hydroxide and potassium carbonate may comprise potassium carbonate in a content of 1-30 wt %, preferably 5-20 wt %.
In the process for treating petroleum coke in accordance with the present disclosure, the non-reactive atmosphere in step (1) may be one or more of nitrogen or inert gases, preferably nitrogen. The inert gases may be one or more of helium, neon, argon, krypton and xenon. When calculated based on the mass of the feed of petroleum coke, the non-reactive atmosphere may be fed in an amount of 100-2000 L, preferably 500-1000 L per kg of the feed of petroleum coke.
In the process for treating petroleum coke in accordance with the present disclosure, the first reactor in step (1) may be a rotary kiln reactor. The rotary kiln reactor may be in any common structure in the art. Those skilled persons may choose according to their needs. Furthermore, the rotation speed may be 0.1-2 rpm, preferably 0.5-1 rpm.
In the process for treating petroleum coke in accordance with the present disclosure, the second heat treatment in step (2) may be operated under conditions of: a pressure of 10-100 Pa (gauge pressure), preferably 20-50 Pa (gauge pressure); and a temperature of 700-1000° C., preferably 800-950° C. The second heat treatment may comprise high-temperature treating and cooling, wherein the high-temperature treating may comprise heating and keeping at a constant temperature. In the heating, it may last 30-300 minutes, preferably 60-180 minutes. In the keeping at the constant temperature, it may last 10-120 minutes, preferably 20-60 minutes. In the cooling, the material after the step of keeping at the constant temperature may be cooled to 300-500° C. The heating may be operated by fuel gas or electric thermal radiation heating. The step of keeping at the constant temperature may be operated by using microwave heating. The cooling may be operated by water cooling or passing gases to cool the material after the step of keeping at the constant temperature.
In the process for treating petroleum coke in accordance with the present disclosure, the second gas phase material obtained in step (2) may be subjected to washing by water and then separating in a separation unit. The separation unit may adopt one separation measure or a combination of more separation measures to obtain different gas products, such as nitrogen, hydrogen and other gases (mainly comprising carbon monoxide, carbon dioxide, and hydrocarbon-containing gases such as methane and the like). The washing by water may be operated by using a Venturi scrubber. The separation unit may comprise one or more devices such as those for cryogenic separation, pressure swing adsorption, membrane separation, and the like. The nitrogen obtained after the separation may be recycled to the first reactor as the non-reactive atmosphere. The carbon dioxide and hydrogen obtained after the separation may be stored as products for other uses. The hydrocarbon-containing gases and carbon monoxide obtained after the separation may be used as fuel gas for the heating. Those skilled persons in the art can choose suitable devices for the separation unit based on the gas composition and actual needs, which is a necessary basic skill for them.
In the process for treating petroleum coke in accordance with the present disclosure, the second reactor is an annular furnace reactor, comprising: a housing, which forms a sealed annular space divided into an inlet/outlet zone, a high-temperature zone and a cooling zone, wherein the high-temperature zone may comprise a heating section and a constant temperature section; a rotary table, which is located inside the housing and arranged along the annular space thereof, wherein the rotary table is rotatable relative to the housing, so that the rotary table receives the first solid phase material in the inlet/outlet zone, carries the first solid phase material into the high-temperature zone and the cooling zones in sequence, and then discharges in the inlet/outlet zone; and baffles, which are located inside the housing and fixed thereon, and are spaced arranged above the rotary table, wherein the baffles comprise a plurality of guiding holes.
Further, in the above embodiments, the heating section may be operated by fuel gas or electric thermal radiation heating, and the heating section may be heated to a temperature of 700-1000° C. in a time of 30-300 minutes; and the constant temperature section may be operated by using microwave heating, at a constant temperature of 700-1000° C. for a time of 10-120 minutes.
Further, in the above embodiments, the heating section may be heated to a temperature of 800-950° C. in a time of 60-180 minutes; and the constant temperature section may be operated by using microwave heating, at a constant temperature of 800-950° C. for a time of 20-60 minutes.
Further, in the above embodiments, the material passed through the constant temperature zone may be cooled to 300-500° C. in the cooling zone. Preferably, the material passed through the constant temperature zone may be cooled to 300-500° C. in the cooling zone via water-cooling coils.
Further, in the above embodiments, the annular furnace reactor may further comprise one or more carrier gas inlets located in the inlet/outlet zone, and a gas outlet located in the high-temperature zone. There may be three carrier gas inlets, located at the starting point, middle point and ending point of the inlet/outlet zone, respectively.
Further, in the above embodiments, the baffles may be perpendicular to the surface of the rotary table, and the plurality of guiding holes may be arranged at the upper one-third to half of the baffles, and the guiding holes may be formed at an opening rate of 20% to 30%. The inlet side of the guiding holes may have a hole diameter greater than that of the outlet side. The guiding holes may be in a circular cone shape.
Further, in the above embodiments, the gas outlet may be located in the constant temperature section of the high-temperature zone.
Further, in the above embodiments, the inlet/outlet zone may comprise a feeder, which may comprise: one or more star valves for preventing gases in the housing from entering into the line for the first solid phase material, and a distributor for evenly distributing the first solid phase material entering into the housing onto the rotary table.
Further, in the above embodiments, the inlet/outlet zone may comprise a discharge system, which is fixed inside the housing and comprises: a spiral discharge device, which outputs a discharge material horizontally from its top; a conveyor belt, which is inclined, with one end located at the top of the spiral discharge device, to deliver the discharge material to the top of the spiral discharge device; and a lifting surface, which is inclined to pick up the second solid phase material located on the rotary table as the discharge material to the other end of the conveyor belt.
Further, in the above embodiments, the lifting surface may comprise: a primary lifting surface, which picks up particles of the second solid phase material with a particle size distribution greater than D10 to the conveyor belt, and a secondary lifting surface, which picks up particles of the second solid phase material with a particle size distribution lower than D10 to the conveyor belt.
Further, in the above embodiments, the lowest end of the primary lifting surface may be in a non-contact state with the surface of the rotary table, and may be made of rigid materials and in a serrated shape. The lowest end of the secondary lifting surface may be in contact with the surface of the rotary table and made of flexible materials.
In the process for treating petroleum coke in accordance with the present disclosure, in step (3), the second solid phase material is cooled to 20-100° C., preferably 50-80° C., and then mixed with water, wherein water is in an amount of 2-10 times, preferably 3-5 times of the weight of the second solid phase material. The cooling may be operated in a slag cooler. The slag cooler may be any one commonly used in the art.
In the process for treating petroleum coke in accordance with the present disclosure, in step (3), the third solid phase material is subjected to further washing and drying to obtain a porous carbon material, preferably activated carbon. The washing may include washing with water and washing with acids. Preferably, the washing with water is operated until the filtrate is neutral. The washing with water may be operated in containers one by one, or on a belt. The washing with acids may be operated with acids which may be hydrochloric acid, sulfuric acid, or a mixture thereof. Usually, acids are used as an aqueous solution with a concentration of 1-10 wt %. The drying may be operated at a temperature of 50-200° C., preferably 80-160° C. The drying may be operated under an air atmosphere, a nitrogen atmosphere, or in vacuum.
In the process for treating petroleum coke in accordance with the present disclosure, in step (4), the precipitant may be calcium oxide and/or calcium hydroxide, preferably calcium hydroxide. Based on calcium ion, the precipitant may be added in an amount of 70-100%, preferably 70-95%, and further preferably 75-90% of the mass of carbonate ion in the first liquid phase material.
In the process for treating petroleum coke in accordance with the present disclosure, in step (4), the first liquid phase material and the precipitant may contact and react at a temperature of 60-95° C., preferably 80-90° C.
In the process for treating petroleum coke in accordance with the present disclosure, in step (4), the fourth solid phase material may be dried and calcined, and then recycled as the precipitant, wherein the drying may be operated at a temperature of 80-200° C., preferably 120-160° C., and the calcining may be operated at a temperature of 700-1200° C., preferably 800-1000° C.
In the process for treating petroleum coke in accordance with the present disclosure, in step (5), the third gas phase material obtained in the evaporation-crystallization may be condensed and recycled to step (3) to mix with the cooled second solid phase material.
In the second aspect of the present disclosure, provided is an apparatus for treating petroleum coke, which comprises an activation unit, wherein the activation unit is an annular furnace reactor, comprising: a housing, which forms a sealed annular space divided into an inlet/outlet zone, a high-temperature zone and a cooling zone, wherein the high-temperature zone may comprise a heating section and a constant temperature section; a rotary table, which is located inside the housing and arranged along the annular space thereof, wherein the rotary table is rotatable in relative to the housing, so that the rotary table receives a mixed feed material of petroleum coke and an activator in the inlet/outlet zone, carries the mixed feed material of petroleum coke and the activator into the high-temperature zone and the cooling zones in sequence, and then discharges in the inlet/outlet zone; and baffles, which are located inside the housing and fixed thereon, and are spaced arranged above the rotary table, wherein the baffles comprise a plurality of guiding holes.
In one variant, the apparatus for treating petroleum coke in accordance with the present disclosure is used to prepare porous carbon materials, such as activated carbon, from petroleum coke.
Further, in the above embodiments, the heating section may be heated to a temperature of 700-1000° C. in a time of 30-300 minutes; and the constant temperature section may be operated by using microwave heating, at a constant temperature of 700-1000° C. for a time of 10-120 minutes.
Further, in the above embodiments, the heating section may be heated to a temperature of 800-950° C. in a time of 60-180 minutes; and the constant temperature section may be operated by using microwave heating, at a constant temperature of 800-950° C. for a time of 20-60 minutes.
Further, in the above embodiments, the mixed feed passed through the constant temperature section may be cooled to 300-500° C. in the cooling zone. For example, the cooling in the cooling zone may be operated via water-cooling coils.
Further, in the above embodiments, the activation unit may further comprise one or more carrier gas inlets located in the inlet/outlet zone, and a gas outlet located in the high-temperature zone. There may be three carrier gas inlets, located at the starting point, middle point and ending point of the inlet/outlet zone, respectively.
Further, in the above embodiments, the baffles may be perpendicular to the surface of the rotary table, and the plurality of guiding holes may be arranged at the upper one-third to half of the baffles, and the guiding holes may be formed at an opening rate of 20% to 30%. The inlet side of the guiding holes may have a hole diameter greater than that of the outlet side. The guiding holes may be in a circular cone shape.
Further, in the above embodiments, the gas outlet may be located in the constant temperature section of the high-temperature zone.
Further, in the above embodiments, the inlet/outlet area may comprise a feeder, which may comprise: one or more star valves for preventing gases in the housing from entering into the line for the mixed feed material, and a distributor for distributing the mixed feed material entering into the housing onto the rotary table.
Further, in the above embodiments, the inlet/outlet zone may comprise a discharge system, which is fixed inside the housing and comprises: a spiral discharge device, which outputs a discharge material horizontally from its top; a conveyor belt, which is inclined, with one end located at the top of the spiral discharge device, to deliver the discharge material to the top of the spiral discharge device; and a lifting surface, which is inclined to pick up the discharge material located on the rotary table to the other end of the conveyor belt.
Further, in the above embodiments, the lifting surface may comprise: a primary lifting surface, which picks up particles of the material with a particle size distribution greater than D10 to the conveyor belt, and a secondary lifting surface, which picks up particles of the material with a particle size distribution lower than D10 to the conveyor belt.
Further, in the above embodiments, the lowest end of the primary lifting surface may be in a non-contact state with the surface of the rotary table, and may be made of rigid materials and in a serrated shape. The lowest end of the secondary lifting surface may be in contact with the surface of the rotary table and made of flexible materials.
Further, in the above embodiments, the apparatus in accordance with the present disclosure may further comprise an activator recovering unit, in which the discharge material is subjected to washing and separating, wherein the obtained liquid phase product is subjected to causticizing to recover the activator.
Further, in the above embodiments, the apparatus in accordance with the present disclosure may further comprise a pretreating unit, in which petroleum coke is mixed with the activator and pulverized, wherein the mixture is heated to 400-500° C. to pre-convert the mixture, which then is sent into the activation unit. The activator and petroleum coke may be mixed in a weight ratio of 1:1 to 5:1. The pretreating unit may be a rotary kiln for pre-converting the mixture.
Further, in the above embodiments, the apparatus in accordance with the present disclosure may further comprise a gas processing unit, in which the gas phase products discharged from the gas outlet of the activation unit are subjected to purifying and separating to output hydrogen gas.
Further, in the above embodiments, the apparatus in accordance with the present disclosure may further comprise a washing and refining unit, in which the discharge material from the activation unit is subjected to washing and separating, wherein the solid product after the separating is dried to obtain the activated carbon.
In the third aspect of the present disclosure, provided is a system for treating petroleum coke, comprising:
Preferably, the system for treating petroleum coke may further comprise:
Further preferably, the system for treating petroleum coke may further comprise:
The system for treating petroleum coke in accordance with the present disclosure, wherein
In the system for treating petroleum coke in accordance with the present disclosure, the feeding line for petroleum coke may be further communicated with a drying unit and a pulverizing unit, in which the feed of petroleum coke is subjected to drying and pulverizing first. The drying may be operated according to well-known methods in the art. Generally, the dried feed of petroleum coke may have a water content of not more than 2 wt %, preferably not more than 1 wt %. The pulverizing may be operated according to well-known methods in the art. The pulverized feed of petroleum coke may have a particle size of not greater than 200 μm, preferably not greater than 150 μm.
In the system for treating petroleum coke in accordance with the present disclosure, the first reactor may be a rotary kiln reactor. The rotary kiln reactor may be a reactor having any structure commonly used in the art. Those skilled persons may select suitable one according to their demands.
In the system for treating petroleum coke in accordance with the present disclosure, the washing and separating unit may comprise a washing unit and a separating unit, which are connected in series. The washing unit may comprise one or more washing equipment, preferably a Venturi scrubber for washing the second gas phase material. The second gas phase material after washing is sent into the separating unit for separation. After separation, nitrogen, hydrogen, carbon dioxide, hydrocarbon-containing gas and carbon monoxide are obtained. The separating unit may comprise one or more devices such as those for cryogenic separation, pressure swing adsorption, membrane separation, and the like. Those skilled persons in the art may select suitable devices for the separating unit based on the gas composition and actual needs, which is a basic skill for those skilled persons in the art.
In the system for treating petroleum coke in accordance with the present disclosure, the second reactor may be an annular furnace reactor, such as the annular furnace reactor mentioned above, which is not repeatedly described herein.
In the system for treating petroleum coke in accordance with the present disclosure, the cooling unit may comprise one or more cooling devices, preferably a slag cooler. The slag cooler may be one or more selected from the group consisting of a drum slag cooler, a vibration slag cooler, a water-cooled slag cooler and a disc slag cooler, preferably a drum slag cooler. The cooling unit is for further cooling the second solid phase material from the second reactor to 20-100° C., preferably 50-80° C. The slag cooler may be a commercially available product in the art. The type of the same may be selected by those skilled persons in the art based on their demands. Such selecting is a basic skill for those skilled persons in the art.
In the system for treating petroleum coke in accordance with the present disclosure, the dissolving and separating unit may be a container with a stirring device, for receiving the cooled second solid phase material from the cooling unit and the washing water from the water feeding line. The two are subjected to mixing and liquid-solid separation to obtain the first liquid phase material and the third solid phase material. The amount of the washing water is generally 2-10 times, preferably 3-5 times of the weight of the second solid phase material. The system for treating petroleum coke in accordance with the present disclosure may comprise one or more dissolving and separating units, preferably two or more, and further preferably two. When there are two or more dissolving and separating units, they can be switched. The number of the units may be determined based on the amount of the second solid phase material. The dissolving and separating unit in accordance with the present disclosure may be operated intermittently. The liquid phase material generated during the evaporation-crystallization in the evaporation-crystallization unit may be used as the washing water.
In the system for treating petroleum coke in accordance with the present disclosure, the washing and drying unit may comprise a washing unit and a drying unit. The washing unit may include washing with water and washing with acids. Preferably, the washing with water is operated until the filtrate is neutral. The washing with water may be operated in containers one by one, or on a belt. The washing with acids may be operated with acids which may be hydrochloric acid, sulfuric acid or a mixture thereof. Usually, acids are used as an aqueous solution with a concentration of 1-10 wt %. The drying may be operated at a temperature of 50-200° C., preferably 80-160° C. The drying may be operated under an air atmosphere, a nitrogen atmosphere or in vacuum.
In the system for treating petroleum coke in accordance with the present disclosure, the regenerating unit may be a heatable container made of alkali-resistant materials with a stirring device, preferably an autoclave.
In the system for treating petroleum coke in accordance with the present disclosure, the evaporation-crystallization unit may be one or more of an autoclave evaporator, a tubular thin film evaporator, a scraper vacuum evaporator, a centrifugal thin film evaporator and the like, preferably an autoclave evaporator.
Compared with the prior art, the method, apparatus and system for treating petroleum coke in accordance with the present disclosure have the following advantages.
The technique and advantages of the present invention will now be described with reference to example embodiments, without limiting the present invention thereto.
Unless otherwise clearly indicated, as used in the entire specification and claims, the term “comprise” or the equivalent terms such as “include” or “have” and the like shall be understood to include the stated elements or components, but do not preclude other elements or components.
In this specification, spatially or temporally relative terms, such as “under”, “below”, “lower”, “on”, “above”, “upper” and the like may be used for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It should be understood that spatially relative terms may be intended to encompass different orientations of the object in use or operation in addition to the orientation depicted in the figures. For example, if the object in the figure is overturned, the elements which are described as “under” or “below” another element(s) or feature(s) will be oriented as “above” the element(s) or feature(s). Therefore, the exemplary term “below” may encompass both orientations of under and above. The object can also have other orientations (rotation of 90 degrees or other orientations) and corresponding explanations should be given to the spatially relative terms used herein.
In this specification, terms “first,” “second,” and the like are used to distinguish two different elements or locations. In other words, in some embodiments, terms “first,” “second,” and the like may be interchanged with each other.
In this specification, all numerical values of parameters (e.g., of quantities or conditions) are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value.
As shown in
In the annular furnace reactor in accordance with the present disclosure, the rotary table rotates relative to the housing. When in use, the rotary table carries feed materials to move inside the housing of the annular furnace. During the feeding and moving, the rotary table is stationary relative to moving parts, which prevents the feed materials from being disturbed, ensuring uniform properties of the products. The annular furnace reactor may also avoid the problem of materials being adhered to the wall that commonly occurs in processes using rotary kilns and the problem of structural collapsing of conveyor that usually occurs due to excessive length of tunnel kilns.
Further, as shown in
After high-temperature activation, the materials may be sent into the cooling zone and subjected to cooling, so that the materials passed through the constant temperature section may be cooled to 300-500° C. In one variant, the materials passed through the constant temperature section may be cooled to 300-500° C. in the cooling zone via water-cooling coils.
Further, as shown in
Nitrogen is usually used as a carrier gas during the activation of petroleum coke. Therefore, the annular furnace reactor further comprises one or more carrier gas inlets and gas outlets. In order to ensure the flux and uniformity of carrier gas, the one or more carrier gas inlets may be located in the inlet/outlet zone. Preferably and nonexclusively, there are three carrier gas inlets, located at the starting point, middle point and end point of the inlet/outlet zone, respectively. The gas outlet may be located in the constant temperature section of the high-temperature zone.
Further, as shown in
Further, as shown in
Further, as shown in
Further, as shown in
The apparatus for treating petroleum coke in accordance with the present disclosure may further comprise a washing and refining unit, in which the discharge material from the activation unit is subjected to washing and separating, wherein the solid phase product after the separating is dried to obtain porous carbon materials (such as activated carbon).
Due to the fact that a large amount of activator is used in the activation of petroleum coke, the apparatus in accordance with the present disclosure may further comprise an activator recovering unit to realize the regeneration and recovery of activator, so as to effectively reduce the consumption of activator and save costs. In particular, in the activator recovering unit, the liquid phase product obtained after the washing and separating of the discharge material in the washing and refining unit is subjected to a causticization reaction with calcium hydroxide, so as to recover the activator (e.g., potassium hydroxide) for reusing. In one variant, the purified water generated in the causticization reaction may be recycled to the washing and refining unit.
Further, the apparatus in accordance with the present disclosure may further comprise a gas processing unit, in which the gas phase products discharged from the gas outlet of the activation unit are subjected to purifying and separating to output hydrogen gas, with the remaining gas being discharged through torch combustion.
By introducing the activator recovering unit and the gas processing unit for recovering activators and carrier gases, the apparatus in accordance with the present disclosure reduces the consumption of activators, saves costs, reduces emissions, and meets the requirements of a green economy.
In Examples in accordance with the present disclosure and Comparative Examples, the feed of petroleum coke had the properties as shown in Table 1. The second reactor in Examples in accordance with the present disclosure was the annular furnace reactor as described above.
This example followed the flow shown in
10 Example 1 was repeated except that the first reactor was operated at a temperature of 350° C., a rotation speed of 0.5 rpm, and a time for the material staying therein of 2 hours; and the second reactor (the annular furnace reactor) was operated under conditions of: the ratio of the length of the heating section to that of the constant temperature section being 9:1, the time for staying in the heating section being 180 minutes, the time for staying in the constant temperature section being 20 minutes, and the pressure in the heating zone being 20 Pa (gauge pressure). The processing conditions and the properties of the products were shown in Table 2.
Example 1 was repeated except that the feed of petroleum coke and an activator (a mixture of potassium hydroxide and potassium carbonate, wherein potassium carbonate was in an amount of 20 wt %) were added in a ratio of 1:5. The precipitant was added into the regenerating unit in an amount of 75% of the mass of carbonate ions in the effluent liquids from the dissolving and separating unit. The first reactor was operated at a temperature of 400° C., a rotation speed of 1 rpm, and a time for the material staying therein of 1 hour. The second reactor (the annular furnace reactor) was operated under conditions of: the temperature in the constant temperature section being 800° C., the ratio of the length of the heating section to that of the constant temperature section being 2:1, the time for staying in the heating section being 120 minutes, the time for staying in the constant temperature section being 60 minutes, and the pressure in the heating zone being 50 Pa (gauge pressure). The processing conditions and the properties of the products were shown in Table 2.
Example 1 was repeated except that the feed of petroleum coke and an activator (a mixture of potassium hydroxide and potassium carbonate, wherein potassium carbonate was in an amount of 5 wt %) were added in a ratio of 1:1. The precipitant was added into the regenerating unit in an amount of 90% of the mass of carbonate ions in the effluent liquids from the dissolving and separating unit. The first reactor was operated at a temperature of 450° C., a rotation speed of 1 rpm, and a time for the material staying therein of 1 hour. The second reactor (the annular furnace reactor) was operated under conditions of: the temperature in the constant temperature section being 950° C., the ratio of the length of the heating section to that of the constant temperature section being 3:1, the time for staying in the heating section being 60 minutes, the time for staying in the constant temperature section being 20 minutes, and the pressure in the heating zone being 40 Pa (gauge pressure). The processing conditions and the properties of the products were shown in Table 2.
Example 1 was repeated except that the second reactor (the annular furnace reactor) was operated under conditions of: the constant temperature section being heated by a thermal radiation tube rather than by using microwave heating, the temperature in the constant temperature section being 900° C., the ratio of the length of the heating section to that of the constant temperature section being 4:1, the time for staying in the heating section being 120 minutes, the time for staying in the constant temperature section being 30 minutes, and the pressure in the heating zone being 30 Pa (gauge pressure). The processing conditions and the properties of the products were shown in Table 2.
Example 1 and Comparative Example 1 were repeated for 10 times respectively. The properties of the products obtained in each time were shown in Table 3.
As shown from the data in the above table, the products obtained in repeating Example 1 in accordance with the present disclosure for 10 times showed a standard deviation of 37 m2/g for specific surface area and a standard deviation of 0.03 cm3/g for pore volume, indicating that there was not significant change in properties. In contrast, the products obtained in repeating Comparative Example 1 for 10 times showed a standard deviation of 162 m2/g for specific surface area and a standard deviation of 0.06 cm3/g for pore volume, indicating that there was significant change in properties.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110029256.5 | Jan 2021 | CN | national |
| 202110029311.0 | Jan 2021 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/070885 | 1/10/2022 | WO |
