Reactor for the sulfochlorination or sulfoxidation of organic compounds

Abstract

Reactor selected from the group of stirred tanks, thin-film reactors, countercurrent columns, bubble-cap columns, sieve-cap columns, jet or venturi scrubbers, cocurrent packed columns, spray towers, submerged-bell reactors, CSTR reactors, bubble column reactors; loop reactors, jet nozzle reactors, tubular reactors, falling-film reactors or microreactors for the sulfochlorination or the sulfoxidation of organic compounds, comprising a reaction vessel with at least one feed line of reactants, with at least one discharge line of reaction product, the reactor wall of which defines a reaction space in which the chemical reaction of at least one organic compound with a mixture of chlorine and sulfur dioxide or with a mixture of oxygen and sulfur dioxide takes place, wherein a) the reaction vessel has at least partially a reactor wall which is transparent to ultraviolet radiation and one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted on the outside of the reactor wall, which emit ultraviolet radiation into the reaction space, and / or b) the reaction vessel has a reactor wall, on the outside of which one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted, which are connected to the reaction chamber via at least one light guide and emit ultraviolet radiation into the reaction chamber, and / or c) at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall, which exposes the contents of the reaction chamber or a part thereof to ultrasonic radiation, and / or d) the reaction vessel has, in addition to the feed line for reactants, at least one further feed line for a reagent suitable for the electrochemical generation or excitation of radicals.

Description

[0001] The invention relates to reactors suitable for the sulfochlorination or sulfoxidation of organic compounds, in particular alkanes.

[0002] By sulfochlorination or sulfoxidation of organic compounds, hydrogen atoms can be substituted by sulfonate groups -SO3H. One example of this is the sulfochlorination or sulfoxidation of alkanes. This leads to the industrial production of secondary alkanesulfonates (hereinafter also referred to as "SAS"). SAS represent an economically important group of anionic surfactants that are used in detergents and cleaning agents, but also in personal care products, fiber preparation, and emulsion polymerization. The sulfochlorination or sulfoxidation of alkanes is described in more detail below. However, these reactions can also be carried out with other organic compounds, for example, aromatics or heteroaromatics.

[0003] It has long been known that SAS can be produced by reacting alkanes (paraffins) with SO2 / Cl2 or with SO2 / O2 under UV irradiation.

[0004] The mechanisms of both reactions are well-studied. It is known that they proceed according to a radical chain mechanism. Details on the course of these reactions can be found, for example, in DE-A-10 2015 004 988 A1 and DE-A-10 2016 009 131 A1.

[0005] Photoreactors for carrying out these reactions are also well known. A wide variety of devices have been proposed as radiation sources. In addition to mercury vapor lamps and photodiodes, gamma radiation sources and excimer lasers have been mentioned. Examples of suitable photoreactors can be found in the patent and published specifications DE 1070625, DE 19905613 A1, DE 102010014712 B2, DE 102011106498 A1, DE 102014012217 A1, DE 102014012218 A1, DE 102014012219 A1, DE 102019003299 A1, DE 102020103656 A1, DE 102021132073 A1 and DE 102021132074 A1,

[0006] It is known from DE 102015004988 A1 and DE 102016009131 A1 that photoreactors with diodes as radiation sources are particularly suitable for the production of SAS.

[0007] Photoreactors usually have a radiation source mounted in the reactor's reaction chamber. Lasers positioned inside or outside the reactor have been proposed for the use of excimer lasers to produce SAS. Radiation sources in direct contact with the reaction medium are preferred for several reasons. On the one hand, the short distance between the radiation source and the reaction medium appears advantageous, and on the other hand, the heat generated by the radiation source can be fed directly and efficiently into the reaction medium. On the other hand, radiation sources in contact with the reaction medium must be cleaned after some time, as deposits form on the surfaces, reducing the radiation output. Furthermore, the reaction medium's absorbance for radiation is often low, meaning that a significant portion of the radiation output is unavailable for the reaction.While this disadvantage can be mitigated by attaching mirrors to the outer wall or outside the reactor, the problem remains, particularly with large reactor cross-sections, that some parts of the reaction medium receive lower radiation power than others.

[0008] It has now been demonstrated that locating radiation sources outside the photoreactor offers significant advantages. This positioning of radiation sources significantly reduces or even completely eliminates the formation of deposits. Furthermore, such radiation sources are easier to replace than radiation sources located inside the reactor—a significant advantage, especially during continuous operation, as the reactor generally does not need to be shut down for replacement or cleaning. Furthermore, when the radiation source is located outside the reactor, the intensity of the radiation increases toward the reactor interior due to geometric constraints. Multiple reflections can therefore be easily generated by installing mirrors inside and outside the reactor, significantly increasing the quantum yield of the reaction.For example, a tube with an external mirror coating can be installed inside the reactor, which reflects the radiation introduced into the reactor from the outside and returns it to the reaction medium. Mirrors can also be installed behind the radiation source, as seen from the reactor's interior, to reflect the radiation reflected inside back into the reactor.

[0009] Furthermore, it has been shown that sulfochlorination and sulfoxidation are best achieved when carried out in the presence of the highest possible radical concentrations and when as many gas / liquid interfaces as possible are present. It is assumed that the reactions occur primarily at the interface of gas bubbles present in the liquid reaction medium. It has been found that the generation of high radical concentrations with a high proportion of gas bubbles in the reaction medium can be achieved through ultrasonic irradiation. Alternatively, a plasma generator can be used to generate high concentrations of chlorine radicals or oxygen radicals. However, the use of redox reactions is also possible.

[0010] Furthermore, it has been shown that sulfochlorination and sulfoxidation of organic compounds can be carried out with very high yields in selected reactors.

[0011] The object of the present invention is to provide a reactor which is suitable for the efficient carrying out of sulfochlorination or sulfoxidation of organic materials.

[0012] Furthermore, the reactor according to the invention should be simple to construct and operate.

[0013] The present invention relates to a reactor selected from the group of stirred tanks or in particular thin-film reactors, countercurrent columns, bubble-cap columns, sieve-cap columns, jet or venturi scrubbers, cocurrent packed columns, spray towers, submerged-bell reactors, CSTR reactors, bubble column reactors; loop reactors, jet nozzle reactors, tubular reactors, falling-film reactors or very particularly preferably microreactors for the sulfochlorination or the sulfoxidation of organic compounds comprising a reaction vessel with at least one feed line of reactants, with at least one discharge line of reaction product, the reactor wall of which defines a reaction space in which the chemical reaction of at least one organic compound with a mixture of chlorine and sulfur dioxide or with a mixture of oxygen and sulfur dioxide takes place, wherein a) the reaction vessel has at least partially a reactor wall which is transparent to ultraviolet radiation and one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted on the outside of the reactor wall, which emit ultraviolet radiation into the reaction space, and / or b) the reaction vessel has a reactor wall, on the outside of which one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted, which are connected to the reaction chamber via at least one light guide and emit ultraviolet radiation into the reaction chamber, and / or c) at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall, which exposes the contents of the reaction chamber or a part thereof to ultrasonic radiation, and / or d) the reaction vessel has, in addition to the feed line for reactants, at least one further feed line for a reagent suitable for the electrochemical generation or excitation of radicals.

[0014] The reactors according to the invention can be devices in which chemical reactions are carried out batchwise or, preferably, continuously. Examples include stirred tank reactors or, in particular, the selected flow reactors mentioned above. These reactors can be equipped with heating or cooling jackets and / or be designed to operate under excess pressure.

[0015] The reactors according to the invention are generally large metal vessels, frequently made of steel, some of which are equipped with a stirrer and heating jacket. Baffles can protrude into the vessel through nozzles. These prevent the entire vessel contents from rotating with the stirrer and thus allow efficient mixing of the reactants. Additional nozzles are often provided on the walls to allow the reactants to flow in and / or to insert measuring instruments. Furthermore, one or more outlet nozzles are provided. The sulfochlorination or sulfoxidation of the organic compounds often takes place under ambient conditions, such as at temperatures of 25°C and at atmospheric or elevated pressure. Examples of elevated pressures range up to 1000 atmospheres, preferably between 2 and 10 atmospheres.Examples of elevated temperatures range up to about 250°C, preferably between 30 and 80°C.

[0016] In addition to the inlet(s) for reactants and the outlet(s) for reaction products, chemical reactors have reactor walls that form the reaction chamber in which the chemical reactions take place. The walls of the reactor according to the invention can be made of a wide variety of materials. The walls must be inert to the chemicals present and formed in the reaction chamber and must be resistant to the reaction temperatures and pressures used. If the reactor according to the invention is a photoreactor (variant a), at least part of the reactor walls must also be transparent to ultraviolet radiation. This can be achieved by installing one or more windows made of UV-transparent material, or the entire reactor wall can be made of such a material.

[0017] If the reactor according to the invention is a photoreactor equipped with light guides (variant b), the reactor walls can have UV-transparent windows or walls; however, materials that do not have UV transparency can also be used.

[0018] Reactors according to the invention of variants c) or d) may also have UV-transparent windows or walls; however, materials that do not have UV transparency may also be used.

[0019] Common materials for UV-opaque reactor walls are plastics, which may be fiber-reinforced, or metals or alloys that are temperature-, tensile-, and corrosion-resistant under the reaction conditions, especially alloyed or unalloyed steel or nickel alloys, such as Hastelloy alloys. ®Reactor walls can be coated with chemical-resistant materials on the inside, which defines the reaction space. Examples include clad, enameled, rubberized, or plastic-coated steels or nickel alloys.

[0020] For the purposes of this description, UV-transparent materials are understood to mean materials which, when UV radiation with a wavelength of 365 nm passes through a plate of the material with a thickness of 1 cm, experience an attenuation of the radiation intensity of less than 50%, preferably less than 80%.

[0021] Accordingly, UV-opaque materials in the context of this description are to be understood as materials which, when UV radiation with a wavelength of 365 nm passes through a plate of the material with a thickness of 1 cm, experience an attenuation of the radiation intensity of at least 50%, preferably of at least 80%.

[0022] The radiation intensity can be determined using photocells.

[0023] Common materials for UV-transparent reactor walls or for UV-transparent window materials are quartz glass, borosilicate glass, silicon carbide, silicon nitride, sapphire, diamond, indium tin oxide or UV-transparent plastics such as polycarbonate or polymethacrylate

[0024] Reactors according to the invention do not necessarily have to correspond to one of types a), b), c), or d). Mixed forms are also possible, in which two or more of types a), b), c), or d) are implemented.

[0025] Preferred variants of these reactors are those in which types a) and c) or a) and d) or a), c) and d) or types b) and c) or b) and d) or b), c) and d) or c) and d) are implemented. Particular preference is given to using a reactor of type a), b) or c) or a combination of types a) and c) or b) and c).

[0026] According to the invention, one or more mercury vapor lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers, and / or UV cold cathode tubes are used as radiation sources for a reactor of type a) or b). These are positioned outside the reactor and emit UV radiation into the reaction chamber. These UV radiation sources are well known and have already been used for sulfochlorination and sulfoxidation, respectively.

[0027] The externally mounted radiation source communicates either directly with the reaction chamber through transparent reactor walls (type a) or the radiation is guided from the externally mounted radiation source into the reaction chamber via optical fibers (type b).

[0028] Known components can be used as light guides, provided they are suitable for conducting UV radiation. The light guides can be in the form of fibers, tubes, rods, or planar optical waveguide structures. Light transmission is achieved by reflection at the interface of the light guide. This can be achieved by total internal reflection due to a lower refractive index of the medium surrounding the light guide, by mirroring the interface, or by applying a suitable refractive gradient.

[0029] UV-transparent materials are used as the core material for suitable light guides. Examples include the aforementioned materials, quartz glass, borosilicate glass, silicon carbide, silicon nitride, sapphire, diamond, indium tin oxide, or UV-transparent plastics such as polycarbonate or polymethacrylate. UV-conductive hollow glass fibers can also be used. Examples of these can be found, for example, in Optics Express, Vol. 32, No. 6, pp. 8520-8526 (2024) (https: / / doi.org / 10.1364 / -OE.509212).

[0030] In addition to photoreactors of type a) or b), mixed forms of type a) and b) can also be used.

[0031] The radiation sources used in the invention generally emit radiation in the solar UV wavelength range (250 nm to 410 nm). These are ideally suited for the photoinitiation of sulfochlorination or sulfoxidation of organic compounds such as alkanes.

[0032] According to the invention, combinations of radiation sources of different wavelength ranges can also be used to emit multiple wavelengths simultaneously. Furthermore, multiple UV radiation sources can be connected in parallel or in series to provide greater radiation outputs.

[0033] In a further preferred variant of the reactor according to the invention, UV radiation sources, in particular light-emitting diodes, are used which are surrounded by a shell made of glass, ceramic material or polymer material which is permeable to the radiation generated.

[0034] In a further preferred variant of the reactor according to the invention, combinations of light-emitting diodes of different wavelength ranges are used and / or several light-emitting diodes are connected in parallel or in series in order to be able to provide greater radiation outputs.

[0035] Preferably, planar arrangements of UV radiation sources, in particular light-emitting diodes, are used, which are arranged parallel to the irradiation zone.

[0036] UV radiation sources emitting wavelengths between 320 and 400 nm, especially between 355 nm and 395 nm, are also preferred. Suitable UV intensities measured at the location of the UV radiation source are between 0.01 and 100 W / cm 2 .

[0037] Particularly preferred are UV radiation sources which emit electromagnetic radiation with peak wavelengths of 365 nm and / or 375 and / or 385 nm.

[0038] It is known that when using UV radiation sources with peak wavelengths of 365 nm and / or 375 and / or 385 nm, surprisingly high yields of SAS can be achieved relative to the amount of power used.

[0039] Particular preference is given to using UV radiation sources that emit line spectra, especially monochromatic or nearly monochromatic UV radiation. It is known that the use of such radiation sources affects the ratio of monoalkanesulfonic acid or salt to dialkanesulfonic acid or salt, resulting in a high content of monoalkanesulfonic acid or salt compared to the content of dialkanesulfonic acid or salt. The latter compounds are undesirable because they are not detergent-active.

[0040] UV light-emitting diodes, UV diode lasers, and / or UV cold cathode tubes are preferred as UV radiation sources. UV light-emitting diodes are particularly preferred.

[0041] In addition to traditional semiconductor devices (hereinafter also referred to as "LEDs"), UV light-emitting diodes also include organic light-emitting diodes (hereinafter also referred to as "OLEDs"). OLEDs differ from LEDs in that they use organic substances as light-emitting materials instead of inorganic semiconductors. Furthermore, the term "UV light-emitting diode" should be understood in its broadest sense and also includes laser diodes.

[0042] The energy efficiency of UV light-emitting diodes has reached a level that makes them particularly attractive as radiation sources for the photoinitiation of chemical reactions. Access to monochromatic radiation is particularly noteworthy. Furthermore, the specific energy efficiency of these emitters is often significantly higher than that of conventional UV radiation sources, such as mercury vapor lamps or xenon arc lamps.

[0043] High-performance UV radiation sources are generally operated with currents higher than 20 milliamperes. This creates special requirements for heat dissipation, which are reflected in special designs. Heat can be dissipated via the power supply lines, the reflector tray, or heat conductors integrated into the radiation body. UV radiation sources are often mounted on heat sinks for operation. High temperatures lead to an immediate reduction in the efficiency of UV radiation sources and, in the long term, to a shortened service life.

[0044] In a preferred embodiment of the invention, the UV radiation sources used are cooled from the rear using gas or liquids such as silicone oils, hydrocarbons, or water, and are applied to a heat-conducting base body. This base body can be a hollow body made of metal, metal alloys, or ceramic, such as copper or aluminum. The hollow body can be rotationally or point-symmetrical, e.g., cylindrical or polygonal, with a diameter-to-length ratio of 1:1 to 1:2000.

[0045] Therefore, a reactor according to the invention is preferred in which the UV radiation sources are cooled during operation, preferably at the rear by means of gas or liquid.

[0046] A measure of the effectiveness of the use of electricity in the reactor according to the invention is the "luminous efficiency." It is expressed as the ratio between the amount of product produced and the amount of electricity used. Since the process carried out in the reactor according to the invention is a photochemical reaction, the scientifically precise luminous efficiency should be expressed as the ratio between the amount of product produced and the amount of quanta emitted ("quantum efficiency"). However, since the exact amount of quanta emitted is difficult or imprecise to determine, and on the other hand, the energy loss, e.g., heat generation, must be taken into account in relation to the production costs, the luminous efficiency defined above has become established in everyday operational practice for process evaluation.

[0047] The UV radiation sources can be mounted on a flat surface, and the reaction medium is irradiated without direct contact with the UV radiation sources. A double-walled reactor is also conceivable, with the UV radiation sources mounted on a first wall, which can be made of metal, metal alloys, or ceramic, e.g., copper or aluminum, and separated from the reaction medium by a second UV-permeable wall.

[0048] Unlike thermal lamps, mercury vapor lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers, and UV cold cathode tubes emit light in a limited spectral range and their light is nearly monochromatic. Therefore, they are particularly efficient compared to other radiation sources, which require color filters to absorb most of the spectrum to achieve a monochrome color characteristic.

[0049] UV radiation sources can be encapsulated with polymers. High-intensity radiation sources are often also housed in glass, quartz, ceramic, or metal casings. Metal casings, as described above, serve to dissipate heat.

[0050] The housing is often shaped like a lens and is positioned above the radiation source. It focuses the emitted radiation into a smaller, definable solid angle.

[0051] In variant c) of the reactor according to the invention, at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall. This generator exposes the contents of the reaction chamber, or part of it, to ultrasonic radiation.

[0052] It has been found that the use of ultrasound causes intensive mixing of the reactants in the reaction chamber, that sonochemical effects of ultrasound influence the reaction kinetics, and that, consequently, the conversion rates of the chemical reactions are significantly improved. The improved mixing of the reactants, combined with the reduction of gas bubbles due to ultrasonic vibrations and cavitation, ensures significantly accelerated kinetics and an increased conversion rate. Sonochemical effects provide the necessary energy to initiate the chemical reactions and achieve higher yields through a more complete reaction. The observed improvements are believed to be based on the principle of acoustic cavitation and the associated forces, including localized heating.

[0053] Cavitation occurs when ultrasound is coupled into the mixture of liquid and gas bubbles present in the reaction chamber. Part of the liquid phase transforms into a vapor phase, resulting in a pressure drop to the level of the liquid's vapor pressure. Ultrasonic cavitation generates very high shear forces and liquid jets of up to 1000 m / s. These liquid jets accelerate the gas bubbles and cause collisions between them, thereby reducing the size of the gas bubbles. In addition, extremely high pressures on the order of hundreds of atmospheres and temperatures on the order of thousands of degrees Kelvin occur within and in the immediate vicinity of the imploding cavitation bubble. These effects cause a significant acceleration of the radical reactions.

[0054] Increasing the interfaces between the liquid and gas phases leads to increased mass transfer between the phases. In reactions between reactants in the liquid and gas phases, only those reactants located at the interfaces can react with each other. The larger the interface, the more contact opportunities arise. Therefore, the reaction rate increases with the degree of fragmentation of the gas phase, and a drastic improvement in the reaction rate is observed as a result of the action of ultrasound on the reaction mixture.

[0055] The ultrasonic radiation is introduced into the reactor according to the invention from the ultrasonic generator, preferably by means of sonotrodes. These are devices that are set into resonant vibrations by the introduction of high-frequency mechanical vibrations and transmit these vibrations to the reaction medium.

[0056] The ultrasonic generators used according to the invention generally generate vibrations in the frequency range between 20 kHz and 1 GHz.

[0057] In variant d) of the reactor according to the invention, the reaction vessel is equipped, in addition to the reactant feed line, with at least one additional feed line for a reagent suitable for the electrochemical generation or excitation of radicals. This introduces another reactant into the reaction medium, which is included in the radical reaction.

[0058] It is known to those skilled in the art that radicals can be generated or stimulated by redox reactions. Redox initiators can generate radicals via a reaction between an oxidizing agent and a reducing agent. For example, by using the redox couple Fe 2+ / Fe 3+generate radicals from hydroperoxides or peroxides. These can be used to promote radical formation from chlorine in sulfoxidation or by exciting the oxygen radical in sulfoxidation. Systems made of Fe 2+ and persulfates or H2O2. Potassium peroxodisulfate, for example, is a suitable persulfate. A redox reaction significantly reduces the activation energy of the initiator decomposition, enabling radical reactions at low temperatures.

[0059] If the sulfochlorination or sulfoxidation is to be supported by the use of redox-active compounds, the invention provides at least one additional feed line into the reaction chamber through which the redox-active components are fed into the reaction mixture. These redox-active components are generally dissolved in an inert solvent. In addition to a feed line simply opening into the reaction chamber, devices are also possible that allow the redox-active components to be injected into the reaction mixture or that allow these components to be divided into several streams, thus achieving a very good distribution of these components in the reaction mixture.

[0060] Preferred is a reactor in which the reaction vessel has one or more windows transparent to ultraviolet radiation or a reactor wall transparent to ultraviolet radiation, and in which one or more UV light-emitting diodes, UV diode lasers, and / or UV cold cathode tubes are mounted on the outside of the reactor wall, which emit ultraviolet radiation into the interior of the reaction vessel. UV light-emitting diodes are particularly preferred.

[0061] Also preferred is a reactor in which one or more UV light-emitting diodes, UV diode lasers, and / or UV cold cathode tubes are mounted on the outside of the reactor wall. These tubes are connected to one or more light guides through which ultraviolet radiation is introduced into the interior of the reaction vessel. UV light-emitting diodes are particularly preferred here as well.

[0062] Also preferred is a reactor in which at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall, which generator exposes the contents of the reaction chamber or a part thereof to ultrasonic radiation.

[0063] Particularly preferred is a reactor in which the window transparent to ultraviolet radiation or the reactor wall transparent to ultraviolet radiation consists of quartz glass, borosilicate glass, silicon carbide, silicon nitride, sapphire, diamond, indium tin oxide, polycarbonate or polymethacrylate.

[0064] Also particularly preferred is a reactor in which a mixer is arranged upstream of at least one feed line of reactants, in which mixer liquid reactants are mixed with chlorine and sulfur dioxide or with oxygen and sulfur dioxide.

[0065] Very particular preference is given to a reactor which has at least one feed line for liquid reactants and at least one feed line for gaseous reactants and which, in particular at the point where the feed line for gaseous reactants enters the reactor, has a device for generating or reducing the diameter of gas bubbles, preferably a frit made of glass or ceramic particles, or injectors which ensure effective swirling of gases and mixing with the reaction mixture.

[0066] Also particularly preferred is a reactor which is a microreactor, in particular a microreactor which consists of a plurality of plates stacked one above the other and in contact with one another, through which a plurality of channels run which define reaction spaces or which are intended as temperature control plates for the passage of heating or cooling fluid, wherein the plates consist of material which is transparent to UV radiation or have windows made of this material or wherein the plates consist of material which is opaque to UV radiation and the ultraviolet radiation is guided from the UV radiation sources into the reaction spaces by means of light guides.

[0067] Particularly preferred microreactors have several stacks of plates with reaction spaces and of temperature control plates in contact with one another, wherein these plates preferably define reaction spaces and temperature control plates alternately with one another.

[0068] Further particularly preferred microreactors have one or more UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes on the top and / or bottom or above and / or below each reaction chamber, which emit ultraviolet radiation into the reaction chambers.

[0069] In a further preferred embodiment of the reactor according to the invention, baffles are provided in the reaction chamber, which obstruct the flow of the reactants in the reaction chamber and thereby promote an improvement in the mixing of the liquid and gaseous components of the reactants.

[0070] Reactors suitable for carrying out continuous chemical reactions are particularly preferred.

[0071] In particular, a mixture of aliphatic hydrocarbons which is liquid at room temperature is fed to the reactors according to the invention as an organic compound, as well as chlorine and sulphur dioxide or oxygen and sulphur dioxide, individually or as a mixture, wherein the gaseous reactants are preferably fed into the reaction space by a device for generating or reducing the diameter of bubbles.

[0072] In the reactors according to the invention, a process for the preparation of secondary alkanesulfonates is preferably carried out by photoinitiated reaction of alkanes with SO2 and Cl2 followed by conversion of the formed alkanesulfonyl chlorides to alkanesulfonates or by photoinitiated reaction of alkanes with SO2 and O2 to alkanesulfonates.

[0073] Typical reaction temperatures are 20°C to 50°C, preferably 25°C to 38°C.

[0074] The process is preferably carried out at reaction pressures of 1 atm (pressureless).

[0075] In the reactors according to the invention, secondary alkanesulfonates are preferably produced with a ratio of monoalkanesulfonate to dialkanesulfonate of greater than 5:1, in particular greater than 8:1, and most particularly from 8:1 to 10:1. These are characterized by improved washing performance when used in detergents and cleaning agents. It has surprisingly been found that a high proportion of monoalkanesulfonate can be achieved through the use of UV light-emitting diodes.

[0076] The isolation of the process products can be carried out by methods known to the person skilled in the art. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE-A-10 2015 004 988 A1

[0004] DE-A-10 2016 009 131 A1 [0004, 0006] DE 1070625

[0005] DE 19905613 A1

[0005] DE 102010014712 B2

[0005] DE 102011106498 A1

[0005] DE 102014012217 A1

[0005] DE 102014012218 A1

[0005] DE 102014012219 A1

[0005] DE 102019003299 A1

[0005] DE 102020103656 A1

[0005] DE 102021132073 A1

[0005] DE 102021132074 A1

[0005] DE 102015004988 A1

[0006] Cited non-patent literature

[0000] Optics Express, Bd. 32, Nr. 6, S. 8520-8526 (2024) (https: / / doi.org / 10.1364 / -OE.509212

[0029]

Claims

[1] Reactor selected from the group of stirred tanks, thin-film reactors, countercurrent columns, bubble-cap columns, sieve-cap columns, jet or venturi scrubbers, cocurrent packed columns, spray towers, submerged-bell reactors, CSTR reactors, bubble column reactors; loop reactors, jet nozzle reactors, tubular reactors, falling-film reactors or microreactors for the sulfochlorination or the sulfoxidation of organic compounds, comprising a reaction vessel with at least one feed line of reactants, with at least one discharge line of reaction product, the reactor wall of which defines a reaction space in which the chemical reaction of at least one organic compound with a mixture of chlorine and sulfur dioxide or with a mixture of oxygen and sulfur dioxide takes place, wherein a) the reaction vessel has at least partially a reactor wall which is transparent to ultraviolet radiation and one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted on the outside of the reactor wall, which emit ultraviolet radiation into the reaction space, and / or b) the reaction vessel has a reactor wall, on the outside of which one or more mercury vapour lamps, noble gas arc lamps, quartz lamps, UV fluorescent lamps, UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are mounted, which are connected to the reaction chamber via at least one light guide and emit ultraviolet radiation into the reaction chamber, and / or c) at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall, which exposes the contents of the reaction chamber or a part thereof to ultrasonic radiation, and / or d) the reaction vessel has, in addition to the feed line for reactants, at least one further feed line for a reagent suitable for the electrochemical generation or excitation of radicals. [2] Reactor according to claim 1, characterized by that the reaction vessel has one or more windows transparent to ultraviolet radiation or a reactor wall transparent to ultraviolet radiation and that one or more UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are attached to the outside of the reactor wall, which emit ultraviolet radiation into the interior of the reaction vessel. [3] Reactor according to claim 1, characterized bythat one or more UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes are attached to the outside of the reactor wall, which are connected to one or more light guides, via which ultraviolet radiation is introduced into the interior of the reaction vessel. [4] Reactor according to one of claims 2 or 3, characterized by that at least one ultrasonic generator is mounted in the reaction chamber or on the outside of the reactor wall, which exposes the contents of the reaction chamber or a part thereof to ultrasonic radiation. [5] Reactor according to at least one of claims 2 or 4, characterized by that the window transparent to ultraviolet radiation or the reactor wall transparent to ultraviolet radiation is made of quartz glass, borosilicate glass, silicon carbide, silicon nitride, sapphire, diamond, indium tin oxide or UV-transparent plastic. [6] Reactor according to at least one of claims 1 to 5, characterized bythat it has a mixer upstream of at least one feed line of reactants in which liquid reactants are mixed with chlorine and sulphur dioxide or with oxygen and sulphur dioxide. [7] Reactor according to at least one of claims 1 to 6, characterized by that it has at least one supply line for liquid reactants and at least one supply line for gaseous reactants. [8] Reactor according to claim 7, characterized in that it has, at the point where the feed line for gaseous reactants enters the reactor, a device for generating or reducing the diameter of gas bubbles, preferably a frit made of glass or ceramic particles or at least one injector which ensures effective swirling of gases and mixing with the reaction mixture. [9] Reactor according to at least one of claims 1 to 8, characterized bythat it is a microreactor which consists of a plurality of plates stacked one above the other and in contact with one another, through which a plurality of channels run which define reaction spaces or which are intended as temperature control plates for the passage of heating or cooling fluid, wherein the plates consist of material which is transparent to UV radiation or have windows made of this material or wherein the plates consist of material which is opaque to UV radiation and the ultraviolet radiation is guided from the UV radiation sources into the reaction spaces by means of light guides. [10] Reactor according to claim 9, characterized by that it has several stacks of plates with reaction spaces and of temperature control plates in contact with one another, wherein these plates preferably define reaction spaces and temperature control plates alternately with one another. [11] Reactor according to one of claims 9 or 10, characterized bythat on its top and / or bottom side or that above and / or below each reaction chamber there are one or more UV light-emitting diodes, UV diode lasers and / or UV cold cathode tubes which emit ultraviolet radiation into the reaction chambers. [12] Reactor according to at least one of claims 1 to 11, characterized by that baffles are provided in the reaction chamber which impede the flow of the reactants in the reaction chamber and thereby promote an improvement in the mixing of the liquid and gaseous components of the reactants. [13] Reactor according to at least one of claims 1 to 12, characterized by that it is suitable for the continuous carrying out of chemical reactions. [14] Reactor according to at least one of claims 1 to 13, characterized bythat a mixture of aliphatic hydrocarbons which is liquid at room temperature (25°C) and chlorine and sulphur dioxide or oxygen and sulphur dioxide, either individually or as a mixture, are fed to the reaction chamber as an organic compound, the gaseous reactants preferably being fed into the reaction chamber by means of a device for generating or reducing the diameter of gas bubbles.