Process for producing activated carbon, activated carbon and use thereof

Abstract

The present invention relates, in a first aspect, to a process for producing activated carbon, said process being characterized in that the carbonized carbon source is activated in the reaction space in a fluidized bed. Furthermore, the present invention is directed to correspondingly obtainable activated carbon and the use thereof, especially as adsorbent in various applications.

Description

[0001] Process for the production of activated carbon, activated carbon and its use

[0002] In a first aspect, the present invention relates to a process for producing activated carbon, which process is characterized in that the carbonized carbon source is activated in a fluidized bed in the reaction chamber. Furthermore, the present invention is directed to correspondingly available activated carbon and its use, in particular as an adsorbent in various applications.

[0003] State of the art

[0004] Activated carbon has a wide range of industrial applications, particularly as an adsorption material for fluids found in liquids or gases, such as air. These materials are typically porous, fine-grained carbons with a large internal surface area, which therefore exhibits corresponding adsorption properties. In addition to their use as an adsorbent in industries such as chemistry, medicine, ventilation and air conditioning, and also for drinking water and wastewater treatment, activated carbon is used in medical applications and as a carrier material for active substances, such as biological or chemical catalysts.

[0005] In activated carbon, pore size and pore size distribution are generally divided into different sizes, namely submicropores with pore sizes of < 0.4 nm, micropores in the range of 0.1 to 2 nm, mesopores in the range of 2 to 50 nm and macropores with sizes of over 50 nm.

[0006] The macropores and mesopores are particularly important for the adsorption properties of activated carbon. They provide the access routes for gases and liquids into the particulate, open-pore activated carbon. Accordingly, they essentially determine the transport and diffusion processes in the inner regions of the particulate activated carbon.

[0007] The adsorption properties can be significantly enhanced through the appropriate formation and proportion of mesopores and, if necessary, macropores. In addition to obtaining activated carbon from plant, animal, or mineral raw materials, it can also be obtained from petrochemicals, including plastics. During production, the initial step is usually carbonization, followed by activation of the carbonaceous raw materials.

[0008] Carbonization generally involves the conversion of the carbon-containing starting material to carbon, i.e., carbonization. The resulting activated carbon then already exhibits its essential mechanical properties, particularly basic porosity, strength, etc.

[0009] Through the activation process following carbonization, the carbon formed during carbonization is partially decomposed or burned off. This results in further structural changes, including changes in the number and size of pores. This activation can be targeted to increase porosity. Activation is typically an oxidizing process in which the carbon is converted into carbon monoxide or dioxide. Activation generally occurs under selective or controlled, usually oxidizing, conditions.

[0010] Activated carbon can be available in various forms depending on the application. Particulate activated carbon is often available in granular and, depending on the application, spherical form. Spherical polymer-based activated carbon, in particular, is particularly free-flowing, extremely abrasion-resistant, and, in this context, particularly hard, which opens up a wide range of applications.

[0011] The production of spherical activated carbon, in particular, requires complex processes, for example, to produce the corresponding spherical activated carbon from petrochemical starting materials. DE 202016 100 320 U1 describes activated carbon, especially particulate activated carbon, with defined porosity properties. Polymers, for example, are used as carbon-containing starting materials. These are sulfonated in a special way to improve and adjust the porosity, especially the meso- and macroporosity, in order to achieve defined porosities while maintaining advantageous mechanical properties, such as stability and resilience.

[0012] Porosity and pore size distribution play a particularly important role with regard to the specific applications of spherical activated carbon. In order to achieve specific adsorption properties and high adsorption kinetics and adsorption capacities, appropriate mesopores and macropores play an important role. This ensures good diffusion into the adsorption pore space of the spherical activated carbon while maintaining excellent adsorption properties, especially at high mesoporosity. Accordingly, as described there, the activated carbon is particularly suitable for the production of certain adsorption filter materials, such as molecular filter laminates for the protection against nuclear, chemical or biological toxins or pollutants (NBC protection), for the adsorption of toxins, pollutants and odors, particularly from gas or air streams, for the purification of gases, especially air, as well as liquids, for the medical field.Pharmaceuticals, for the sorptive storage of gases or liquids, etc. They also play an important role in wastewater treatment.

[0013] The spherical activated carbons described therein are said to be characterized by appropriate porosity and thus high adsorption capacity while maintaining mechanical stability. Processes for producing this activated carbon are described. However, a disadvantage of the processes described therein is the complex activation process. Activation takes place in at least semi-continuous processes within a rotary kiln at high temperatures and with a long residence time, making this process costly and time-consuming.

[0014] Against this background, one object of the present invention is to provide improved processes for producing, in particular, spherical activated carbon with high adsorption capacity while maintaining mechanical stability. These processes are characterized by increased cost efficiency and shortened production times. The activated carbon produced in this way, which is usually spherical, exhibits the desired porosity and stability properties and is particularly suitable as an adsorbent in filters or filter materials, such as the aforementioned molecular filter laminates.

[0015] Brief description of the invention

[0016] In a first aspect, a method for producing activated carbon is provided, this method comprising the steps of a) providing a carbonized carbon source in a reaction chamber; b) supplying a fuel gas and a combustion gas into a combustion chamber and combusting both components to obtain a process gas; c) fluidizing the carbonized carbon source in the reaction chamber in a fluidized bed; d) heating the fluidized carbon source; e) introducing the process gas according to step b) into the fluidized bed, and f) activating the carbonized carbon source in the fluidized bed of the reaction chamber to obtain the activated carbon.

[0017] Furthermore, available activated carbon is described as well as its use as adsorbent, adsorption filter and filter material, in particular in air and gas filters, protective equipment and protective objects as well as in (waste) water treatment.

[0018] Short description of the figures

[0019] Figure 1 shows a process plant for carrying out the method according to the invention.

[0020] Description of the invention

[0021] The invention is directed to a method for producing activated carbon, comprising the steps: a) providing a carbonized carbon source in a reaction chamber; b) supplying a fuel gas and a combustion gas into a combustion chamber and combusting them to obtain a process gas; c) fluidizing the carbonized carbon source in the reaction chamber in a fluidized bed; d) heating the fluidized carbon source; e) introducing the process gas according to step b) into the fluidized bed, and f) activating the carbonized carbon source in the fluidized bed of the reaction chamber to obtain the activated carbon.

[0022] The list of process steps does not represent a fixed order. For example, the provision of the carbonized carbon source in a reaction chamber can be provided before, during, or after the process gas has been received. The process according to the invention allows a predefined quality of activated carbon to be obtained. This relates in particular to the pore type and their volume fractions. These can be obtained in the desired (predefined) manner by appropriate reaction conditions.

[0023] In this context, "carbon source" refers to any substance containing carbon, typically organic starting materials. Carbon sources can have any particle shape; in a preferred embodiment, they are granular, particularly spherical.

[0024] The process allows a cost-efficient and, compared to previous processes, shortened production process while obtaining, in particular, spherical activated carbon with desired micro-, meso- and / or macropores and their specific volume fractions.

[0025] With regard to the activated carbon or activated carbon particles (hereinafter also referred to as activated carbon) according to the invention as such, the parameters listed for this purpose are determined using standardized or explicitly specified determination procedures or methods familiar to the person skilled in the art. In particular, the parameters relating to the characterization of porosity or pore size distribution and other adsorption properties generally result from the corresponding nitrogen sorption isotherms of the activated carbon in question or the measured products. Furthermore, the pore distribution, particularly with regard to the content of pores of a defined size in relation to the total pore volume, can be determined based on DIN 66135-1.

[0026] The applicant surprisingly discovered that the use of pulsating fluidized beds or fluidized beds to activate the carbonized carbon source can significantly shorten the treatment time. This allows for both the production of larger quantities of the desired activated carbon and a cost-saving process.

[0027] In a preferred embodiment, the carbon source contains at least one polymer and / or at least one polymer-based compound. The carbon source can comprise at least one or more polymer-based compounds. The carbon source can also comprise several substances, at least one of which contains carbon, preferably a polymer or a polymer-based compound. The term "polymer-based compound" refers to a substance whose molecular structure is composed primarily or entirely of a large number of similar, interconnected units, e.g., many synthetic organic materials used as plastics and resins. Polymer-based compounds can, for example, consist of polyethylene and / or polypropylene units. For example, the carbon source can be a styrene-based polymer.

[0028] In one embodiment, at least one polymer and / or polymer-based compound is present in a modified form, for example, oxidized, hydroxylated, and / or sulfonated. For example, a sulfonated styrene-divinylbenzene copolymer can be used. The carbon source can contain modified and unmodified polymers and / or polymer-based compounds. For example, a styrene-divinylbenzene copolymer can be used. For example, the styrene-divinylbenzene copolymer can have been previously sulfonated. Furthermore, the carbon source can contain a furfuryl alcohol-based polymer, a phenol-based polymer such as phenol-furan resin or phenol-formaldehyde resin, and / or a furan resin.

[0029] This means that according to the invention, it can be provided in particular that a starting material based on organic polymers, in particular based on divinylbenzene-crosslinked polystyrene, preferably based on styrene / divinylbenzene copolymers, is used as the starting material. In this context, the divinylbenzene content in the starting material can be in the range from 0.1 wt.% to 25 wt.%, in particular 0.5 wt.% to 20 wt.%, preferably 1 wt.% to 15 wt.%, more preferably 2 wt.% to 10 wt.%, based on the starting material. Such a material is particularly suitable for use in the process because, in particular, it already has a defined pore system which is particularly accessible to the sulfonation provided for according to the invention.

[0030] According to the invention, fuel gas is ignited together with combustion air (combustion gas) in the combustion chamber to obtain an oxygen-free gas, which is referred to below as the process gas. Examples of fuel gases that can be used are hydrogen, methane gas, propane gas, and / or butane gas. However, other fuel gases can also be used. In particular, fuel gases with a higher carbon content can be used. Mixtures of individual gases can also be used. The combustion gas can be pure oxygen or contain oxygen. With certain gas combinations, no additional ignition of the gas mixture is necessary to initiate combustion, for example with hydrogen and oxygen.

[0031] In one embodiment, the combustion takes place substoichiometrically. This means that less oxygen is supplied than is necessary for complete stoichiometric combustion. The combustion gas ratio is lambda < 1. The product of the combustion is an oxygen-free process gas. An oxygen-free process gas within the meaning of this application is a gas that does not contain molecular oxygen (O2). However, an oxygen-free gas within the meaning of this application can contain elemental oxygen, such as in CO2 or CO.

[0032] The process gas is fed into the reaction chamber and displaces or mixes with the existing inert gas. The process gas consists at least partially of the oxygen-free gas obtained from the combustion chamber through the substoichiometric combustion of the fuel gas with the combustion gas. An inert gas can also be added. Possible inert gases include nitrogen, helium, or argon. Upon entering the fluidized bed, the process gas has a temperature of, for example, at least 620 °C, preferably at least 800 °C, more preferably at least 920 °C, such as at least 1000 °C or higher.

[0033] In one embodiment, the temperature of the process gas is in the range of 620 to 1000 °C, such as between 800 °C and 1000 °C.

[0034] The carbonized carbon source is introduced into the reaction chamber and fluidized by an inert gas. Nitrogen, for example, can be used as an inert gas. The carbonized carbon source is preheated to the reaction temperature by the inert gas or the process gas. The reaction temperature can be between 620 and 1000 °C, such as between 800 and 1000 °C, preferably between 920 and 1000 °C. The reaction chamber can be additionally heated externally, for example, by a jacket heater, or within the fluidized carbon source by inductive heat generation or microwaves.

[0035] The activation of the carbonized carbon source takes place in the fluidized bed. The temperature is at least 650 °C. During activation, two reactions can essentially occur:

[0036] C + H2O CO + H2or C + CO22 CO

[0037] Pores are created by the partial combustion of carbon from the carbonized carbon source. The ratio of water vapor to carbon dioxide can influence the ratio of micropores to mesopores. According to the IIIPAC definition, mesopores are pores with a pore diameter between 2 nm and 50 nm, and micropores are pores < 2 nm. The carbon dioxide content can be adjusted using carbon-containing gases in the fuel gas, such as methane gas, propane gas, and / or butane gas. The water content in the process gas can be adjusted using the proportion of hydrogen in the fuel gas. Ratios of 80% H2O to 20% N2, or 70% H2O to 30% N2, or 50% H2O to 30% N2 to 20% CO2, are particularly advantageous. The pore distribution can be influenced by the ratio of inert gas, carbon dioxide, and water.

[0038] On the side of the fluidized bed opposite the process gas supply line, the gas is discharged under slight suction.

[0039] Due to the better heat transfer in a fluidized bed, the heating of the starting materials, especially the carbon source, for fluidization and to the reaction temperature can be shortened.

[0040] In a preferred embodiment, the fluidized bed is a pulsating fluidized bed. Alternating negative and positive pressures are generated.

[0041] A pulsating fluidized bed can be characterized by a non-constant gas volume flow, which can lead, for example, to a modulated plug flow in a tubular reaction chamber.

[0042] Such pulsation can be generated, for example, by rotating flaps that can temporarily at least partially close and / or open the process gas inlet line and / or the reaction gas outlet line. The pulsating fluidized bed can also be generated by pulsating combustion.

[0043] The process gas flow rate can be selected so that the pulse volume can propagate completely as a plug flow during the expansion phase of the fluidized bed. To achieve this, the process gas flow rate can be above the fluidization point of the carbon source at its maximum pressure. The process gas flow rate can be slightly below the fluidization point of the carbon source at its minimum pressure. This results in a cyclically pulsating fluidized bed.

[0044] Due to the pulsation of the fluidized bed and the resulting pressure changes, the diffusion into and out of the initial and expanding pore space in the carbon particle and thus the partial oxidation reaction is accelerated even further compared to a normal fluidized bed.

[0045] In one embodiment, the flap is arranged in a rotating manner on an inflow line or a discharge line so that it can periodically close and open the respective line. The frequency can be adjusted by a control unit. For example, the speed can be measured and / or adjusted for this purpose. Multiple flaps can also be arranged. For example, one flap can be attached to the inflow line and one flap to the discharge line. Multiple flaps can also be attached to one line. The flap or flaps can be switched in a coordinated manner. The flap or the switching of the flaps can create a negative and / or positive pressure in the reaction chamber. A cyclically pulsating fluidized bed can be created by alternately closing and opening the inflow and discharge lines.The point in time at which the maximum pressure prevails in the reactor chamber, for example due to the valve switching, is referred to as the pressure maximum. It is preferably in the overpressure range. The point in time at which the minimum pressure prevails in the reactor chamber, for example due to the valve switching, is referred to as the pressure minimum. It can be in the underpressure range.

[0046] In a preferred embodiment, the pulsating fluidized bed is generated by pulsating combustion of the fuel gas. In this case, a fuel gas and combustion air are periodically ignited in a combustion chamber. The temperature, frequency, amplitude, and chemical composition of the combustion product can be adjusted by the gas composition. A frequency as high as possible, for example, 40 to 60 s-1, is particularly advantageous. The combustion temperature can be, for example, between 650 and 1000 °C, preferably between 920 and 1000 °C.

[0047] In a preferred embodiment, additional oxygen-free gases are added to the process gas before it enters the fluidized bed. For example, an inert gas can be added to the process gas. Possible inert gases include nitrogen, helium, or argon. Carbon dioxide, for example, can be added to the process gas.

[0048] In another embodiment, in addition to the combustion product of the substoichiometrically burned fuel gas and an inert gas such as nitrogen, finely atomized water and / or steam are added to the process gas before it enters the fluidized bed. If water is added in the form of a spray, it evaporates into steam due to the high temperatures. For example, the steam can have a temperature between 160 and 1000 °C.

[0049] By adding water and / or steam, the proportion of water vapor in the process gas can be increased. Furthermore, by adding water and / or steam, the temperature of the process gas can be adjusted, for example, reduced.

[0050] The speed of activation can be further increased by adding steam, for example.

[0051] In one embodiment, the temperature in the reaction chamber is at least 650 °C, preferably at least 800 °C, more preferably at least 920 °C, even more preferably at least 1000 °C or more.

[0052] The method may further comprise the step of removing the reaction gas from the reaction chamber, e.g. by means of appropriate devices such as blowers, etc.

[0053] In addition, the activated carbon can be discharged via a suitable outlet. For example, the activated carbon is blown out using an inert gas or extracted using the Venturi effect to allow batch production.

[0054] In another aspect, the particulate polymeric organic starting materials are those that have been sulfonated prior to carbonization.

[0055] Corresponding procedures are described, for example, in DE 20 2016 100 320 U1, which are hereby incorporated.

[0056] In one embodiment, the reactor may correspond to or be modeled on the principle of a pulse tube, pulsation reactor or pulse engine.

[0057] The reactor preferably consists of several chambers, such as at least two chambers, a combustion chamber, and a reaction chamber. Reactors with more chambers, for example, multiple reaction chambers, are also conceivable. A reactor suitable for the present process is, for example, a high-temperature fluidized-bed reactor or another tubular reactor preceded by a combustion chamber. The reactor shape can be configured, for example, as shown in Figure 1. However, any other design with at least one combustion chamber and at least one reaction chamber is also conceivable.

[0058] Figure 1 shows a reactor according to the invention, also referred to as a process plant 1, with a combustion chamber 2. Gases are introduced into this combustion chamber via inlets 6 (fuel gas inlet) and 8 (combustion gas inlet) and converted into process gas in the combustion chamber. Adjacent to the combustion chamber is a mixing chamber 7 into which, on the one hand, the carbonized carbon source is introduced via supply line 11 and, on the other hand, an inert gas is introduced via supply line 9 to fluidize the carbonized carbon source.

[0059] The process gas is introduced into the reaction chamber 3, in which the fluidized carbon source with the inert gas is located, via the mixing chamber 7 or directly into the reaction chamber 3. If necessary, water or steam can be added to the process gas via the feed line 10 before it enters the reaction chamber and the fluidized bed there. In the reaction chamber 3, the carbonized carbon source is activated, preferably in a pulsating fluidized bed, to obtain the activated carbon, preferably in spherical form. The settling chamber reduces the gas velocity, in particular such that the carbon source is no longer fluidized, and thus prevents the particles of the carbon source from escaping from the reaction chamber 3, with reaction gas being discharged via the reaction gas outlet 5.

[0060] The reaction chamber is designed so that a fluidized bed can be generated therein, for example, a fluidized-bed reactor. Among other advantages, a diameter-to-height ratio of the reaction chamber is such that the fluidized bed extends across the entire reactor cross-section. In a preferred embodiment, the diameter-to-height ratio of the reaction chamber is dimensioned such that a pulsating fluidized bed cyclically pulsates across the entire reactor cross-section.

[0061] Furthermore, the reaction chamber has an outlet for the activated carbon particles obtained in the reaction chamber. After the predefined activated carbon quality has been achieved, the reaction is terminated, in particular by no longer adding any further process gas. In one embodiment, the inert gas is added at a lower temperature to terminate the fluidization of the carbon source particles and obtain the particles with a predefined quality.

[0062] The activated carbon according to the invention can be used for the adsorption of toxins, pollutants and odors, in particular from gas or air streams, or for the purification or treatment of gases, in particular air or liquids, in particular water, or for use in adsorption filter materials, in particular for the production of molecular filter laminates, or as sorption storage for gases or liquids, or in the food industry, in particular for the treatment and / or decolorization of foodstuffs, or in the field of medicine or pharmacy, in particular as a medicament or medicament component, orfor the manufacture of protective equipment and / or protective articles of all kinds, in particular molecular filter laminates, in particular for the civil or military sector, such as protective suits, protective gloves, protective footwear, protective socks, head protection clothing and the like, and protective covers of all kinds, preferably all of the aforementioned protective materials for NBC use and / or with a protective function against radioactive pollutants and / or toxic substances and / or against biological pollutants and / or toxic substances and / or against chemical pollutants and / or toxic substances, respectively.For the production of filters and filter materials of all kinds, in particular for the removal of pollutants, odors, and toxins of all kinds, preferably for the removal of radioactive pollutants and / or toxins and / or biological pollutants and / or toxins and / or chemical pollutants and / or toxins, in particular from air and / or gas streams, such as ABC protective mask filters, odor filters, surface filters, air filters, in particular filters for indoor air purification, adsorption-capable support structures, and filters for the medical sector. Due to the special properties of the activated carbon produced according to the invention, it is therefore suitable for a wide variety of different technical applications.

[0063] Furthermore, the present invention relates to the use of the activated carbon that can be produced according to the invention in protective equipment or protective articles of all kinds, in particular for the civilian or military sector, in particular molecular filter laminates, for protective suits, protective gloves, protective footwear, protective socks, head protection clothing and the like, as well as protective covers, preferably all of the aforementioned protective equipment and / or protective articles for ABC use and / or with a protective function against radioactive pollutants and / or toxic substances and / or against biological pollutants and / or toxic substances and / or against chemical pollutants and / or toxic substances, produced using an activated carbon.

[0064] Finally, the present invention also relates to the use of the activated carbon that can be produced according to the invention in filters and filter materials of all kinds, in particular for removing harmful, odorous and toxic substances of all kinds, preferably for removing radioactive harmful and / or toxic substances and / or biological harmful and / or toxic substances and / or chemical harmful and / or toxic substances, in particular from air and / or gas streams, such as in protective mask filters, odor filters, surface filters, air filters, in particular filters for room air purification, adsorptive support structures and filters for the medical sector.

[0065] Examples

[0066] Example 1

[0067] Example 1 compares the activation of a carbon source in a rotary kiln indirectly heated by jacket heating and in a pulsating fluidized bed using pulsating combustion. 10 kg of a previously sulfonated styrene-divinylbenzene copolymer, carbonized at a maximum temperature of 920 °C under an inert atmosphere, was used as the carbon source. The carbon source was introduced into the reaction chamber and heated to the activation temperature of 957 °C under an inert atmosphere. Subsequently, the preheated process gas (N2:H2O:CO2 ratio 30:70:0) was fed from the combustion chamber into the reaction chamber.

[0068] After reaching a specific surface area of ​​1000 m 2 / g, determined by pre-calibrated 1-point BET, the activation was terminated by interrupting the process gas flow and cooling the resulting activated carbon to below 180 °C by supplying an inert gas.

[0069] A significantly reduced activation time was required for the pulsating fluidized bed, as shown in Table 1 below.

[0070] The resulting spherical activated carbon particles were analyzed for total pore volume and micropore volume. The specific surface area and total pore volume were determined according to DIN ISO 9277:2014 by previously measuring a low-temperature nitrogen sorption isotherm. The micropore volume was determined using the Dubinin-Radushkevich method and by t-plot.

[0071] In addition, the pore size distribution was determined using density functional theory (DFT). A DFT kernel for N2 / 77 K on a carbon surface and the assumption of slit pore geometry was used as the calculation model ("N2 at 77 K on carbon (slit pore, QSDFT, equilibrium model")). The methodology used is part of the kernel included in the evaluation software. The volumetric sorption measuring device AUTOSORB-IQ from Quantachrome GmbH & Co. KG was used to determine the nitrogen sorption isotherm.

[0072] The results of the texture parameters derived from the nitrogen isotherms are summarized in Table 1.

[0073] Table 1 : Determined texture parameters of activated carbon produced by a pulsating fluidized bed and a rotary kiln

[0074] It is clear that the total pore volume is increased when comparing the process according to the invention with a pulsating fluidized bed to the process using a rotary kiln. Furthermore, the required activation time for the production of activated carbon is significantly reduced, from 800 minutes to 280 minutes, as shown in Table 1.

[0075] Example 2:

[0076] Similar to Example 1, Example 2 compares the activation of a carbon source in a rotary kiln indirectly heated by jacket heating and in a pulsating fluidized bed by pulsating combustion. 10 kg of a previously sulfonated styrene-divinylbenzene copolymer, carbonized at a maximum temperature of 920 °C under an inert atmosphere, was used as the carbon source. The carbon source was introduced into the reaction chamber and heated to the activation temperature of 920 °C under an inert atmosphere. Subsequently, the preheated process gas (N2:H2O:CO2 ratio 30:70:0) was fed from the combustion chamber into the reaction chamber. After reaching a specific surface area of ​​1600 m 2 / g, determined by pre-calibrated 1-point BET, the activation was terminated by interrupting the process gas flow and cooling the resulting activated carbon to below 180 °C by introducing an inert gas. A significantly reduced activation time was required for the pulsating fluidized bed, as shown in Table 2 below. The resulting spherical activated carbon particles were analyzed for total pore volume and micropore volume. The specific surface area and total pore volume were determined according to DIN ISO 9277:2014 by previously measuring a nitrogen low-temperature sorption isotherm. The micropore volume was determined using the Dubinin-Radushkevich method and by t-plot.

[0077] In addition, the pore size distribution was determined using density functional theory (DFT). A DFT kernel for N2 / 77 K on a carbon surface and assuming a slit pore geometry was used as the calculation model ("N2 at 77 K on carbon (slit pore, QSDFT, equilibrium model")). The methodology used is part of the kernel included in the evaluation software. The volumetric sorption measuring device AUTOSORB-IQ from Quantachrome GmbH & Co. KG was used to determine the nitrogen sorption isotherm.

[0078] The results of the texture parameters derived from the nitrogen isotherms are summarized in Table 2.

[0079] Table 2:

[0080] Determined texture parameters of activated carbon produced by a pulsating fluidized bed and a rotary kiln It is clear that the total pore volume is increased when comparing the process according to the invention with a pulsating fluidized bed to the process using a rotary kiln. Furthermore, the required activation time for the production of activated carbon is significantly reduced, from 1000 minutes to 415 minutes, as shown in Table 2.

[0081] Example 3

[0082] Example 3 shows the influence of the process gas composition on the pore size distribution.

[0083] Ten kg of a previously sulfonated styrene-divinylbenzene copolymer, carbonized at a maximum temperature of 920 °C under an inert atmosphere, was used as the carbon source. The carbon source was introduced into the reaction chamber and heated to the activation temperature of 957 °C under an inert atmosphere. Subsequently, the preheated process gas (N2:H2O:CO2 ratio 30:70:0) was fed from the combustion chamber into the reaction chamber.

[0084] After reaching a specific surface area of ​​1000 m 2 / g, determined by 1-point BET, the activation was terminated by interrupting the process gas flow and cooling the resulting glassy carbon to below 180 °C by supplying an inert gas.

[0085] By using carbon dioxide, the total pore volume was significantly increased while maintaining a constant specific surface area, while the micropore volume remained the same. Thus, the proportion of mesopores could be increased.

[0086] Table 3: Determined texture parameters of the activated carbon for different process gas compositions The data in Table 3 clearly shows that the total pore volume can be changed by adjusting the process gas composition accordingly, while the micropore volume remains constant. Accordingly, it is possible to significantly increase the porosity in the other regions, particularly in the mesopore region between 2.8 nm and 4.4 nm, by varying the process gas composition. This pore formation in the mesopore region will be achieved with the same activation time.

[0087] According to the invention, it is possible to adjust the activated carbon quality and in particular the pore formation accordingly.

[0088] List of reference symbols

[0089] 1 Process plant

[0090] 2 Combustion chamber 3 Reaction chamber

[0091] 4 Calming zone

[0092] 5 Reaction gas outlet

[0093] 6 Fuel gas inlet

[0094] 7 Mixing chamber 8 Combustion gas inlet

[0095] 9 Inert gas inlet

[0096] 10 Water vapor / Water

[0097] 11 Inlet carbonized carbon source

[0098] 12 Activated carbon outlet

Claims

Patent claims 1 . A process for producing activated carbon, comprising the steps: a. providing a carbonized carbon source in a reaction chamber; b. feeding a fuel gas and a combustion gas into a combustion chamber and combusting them to obtain a process gas; c. fluidizing the carbonized carbon source in the reaction chamber in a fluidized bed; d. heating the fluidized carbon source; e. introducing the process gas according to step b) into the fluidized bed, and f. activating the carbonized carbon source in the fluidized bed of the reaction chamber to obtain activated carbon.

2. The process for producing activated carbon according to claim 1, further comprising the step of discharging the reaction gas from the reaction space.

3. The process for producing activated carbon according to one of claims 1 or 2, characterized in that the fluidized bed is a pulsating fluidized bed.

4. The process for producing activated carbon according to claim 3, characterized in that the pulsating fluidized bed is formed by pulsating combustion of the fuel gas to produce the process gas.

5. The process for producing activated carbon according to one of the preceding claims, characterized in that additional oxygen-free gas is added to the process gas before it enters the fluidized bed.

6. The process for producing activated carbon according to one of the preceding claims, wherein finely atomized water and / or steam is additionally added to the process gas before it enters the fluidized bed.

7. The process for producing activated carbon according to any one of the preceding claims, wherein the process gas is introduced into the reaction chamber in an oxygen-free state.

8. The process for producing activated carbon according to one of the preceding claims, characterized in that the temperature of the process gas upon entry into the reaction chamber is at least 650 °C, preferably at least 800 °C, more preferably at least 920 °C, such as at least 1,000 °C or higher.

9. The process for producing activated carbon according to any one of the preceding claims, characterized in that the carbon source contains at least one polymer and / or at least one polymer-based compound.

10. The process for producing activated carbon according to any one of the preceding claims, characterized in that the carbon source is at least one of a particulate polymeric organic starting material, such as styrene-based polymer.

11. The process for producing activated carbon according to any one of the preceding claims, wherein the carbon source has been sulfonated prior to carbonization.

12. The process for producing activated carbon according to any one of the preceding claims, characterized in that the carbonized carbon source is heated in the reaction chamber to at least 650 °C, such as at least 800 °C, more preferably at least 920 °C, such as 1,000 °C or more.

13. The process for producing activated carbon according to any one of the preceding claims, characterized in that the activation reactor is a pulsation reactor.

14. Activated carbon, in particular particulate, such as spherical, activated carbon with high meso- and / or macropolene volume fraction obtainable by a process according to one of claims 1 to 13. Use of the activated carbon obtainable according to one of the processes 1 to 13 as an adsorbent, as a filter and filter material, in particular also in protective equipment and protective articles, as well as in (waste) water treatment.

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