PLANT FOR HYDROGEN PEROXIDE PRODUCTION AND PROCESS USING IT
20190388860 ยท 2019-12-26
Assignee
Inventors
Cpc classification
B01J19/0006
PERFORMING OPERATIONS; TRANSPORTING
B01J2219/00049
PERFORMING OPERATIONS; TRANSPORTING
B01J2219/00022
PERFORMING OPERATIONS; TRANSPORTING
B01J10/00
PERFORMING OPERATIONS; TRANSPORTING
International classification
B01J10/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An autoxidation process for producing hydrogen peroxide may be performed using a plant that includes at least two skid mounted modules selected from: a skid mounted module comprising at least one hydrogenator to hydrogenate an anthraquinone in a working solution; a skid mounted module comprising at least one oxidizer to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide; optionally a skid mounted module configured to compress air to feed oxygen into the at least one oxidizer of the oxidizer skid, and when said air compressor skid is present, a further skid mounted module configured to recover solvent; a skid mounted module configured to extract the hydrogen peroxide from the working solution; and a skid mounted module comprising at least one means to deliver a hydrogen peroxide solution to a point of use and/or optionally to a storage tank.
Claims
1-17. (canceled)
18. An autoxidation process for producing hydrogen peroxide, which is denoted as an AO-process, the process comprising the use of a plant, wherein the plant comprises at least two skid mounted modules selected from the group consisting of: a skid mounted module comprising at least one hydrogenator to hydrogenate an anthraquinone in a working solution, denoted as hydrogenation skid 1; a skid mounted module comprising at least one oxidizer to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as oxidizer skid 2; optionally a skid mounted module configured to compress air, denoted as process air compressor skid 3, to feed oxygen into the at least one oxidizer of the oxidizer skid 2, and when said process air compressor skid 3 is present in said plant, a further skid mounted module configured to recover solvent, denoted as solvent recovery unit skid 4, when oxygen from the air is used to feed oxygen into the at least one oxidizer of said oxidizer skid 2; a skid mounted module configured to extract the hydrogen peroxide from the working solution, denoted as extraction skid 5; and a skid mounted module, denoted as skid 6, comprising at least one means to deliver a hydrogen peroxide solution to a point of use and/or optionally to a storage tank; wherein the plant is a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide of up to 20 kilo tons per year; wherein the plant is located proximal to or on-site of an end user site or a customer site utilizing hydrogen peroxide in an industrial application; wherein the AO-process runs in continuous operation; and wherein at least one of the working solution and a catalyst are periodically replaced and/or treated for regeneration or reactivation with a low frequency.
19. The process according to claim 18, wherein each skid comprises exchangeable equipment items.
20. The process according to claim 18, wherein the plant comprises said hydrogenation skid 1, said oxidation skid 2 and said extraction skid 5, and wherein said hydrogenation skid 1, said oxidation skid 2 and said extraction skid 5, together with any optional skid, are designed as a modular reactor system.
21. The process according to claim 20, wherein the plant is a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide of a range selected from the group consisting of 2-3 kilo tons per year, 3-5 kilo tons per year, 5-7.5 kilo tons per year, 7.5-10 kilo tons per year, 10-12.5 kilo tons per year, and 12.5-15 kilo tons per year.
22. The process according to claim 18, wherein the hydrogenation skid 1 comprises at least one equipment items selected from the group consisting of a hydrogen recycle compressor, a catalyst filter, an oxidizer feed tank, an oxidizer feed pump, and a guard catalyst bed.
23. The process according to claim 18, wherein the oxidizer skid 2 comprises at least one equipment items selected from the group consisting of an oxidizer feed cooler, a degasser, an extraction feed pump, an off-gas condenser, and an off-gas demister.
24. The process according to claim 18, wherein the extraction skid 5 comprises at least one equipment items selected from the group consisting of a cooler, a coalescer and a hydrogenator feed pump, and optionally an extraction column and/or being connectable to an extraction column.
25. The process according to claim 18, wherein the optional process air compressor skid 3 comprises at least one equipment items selected from the group consisting of a process air compressor package, a suction air filter, and an after cooler-condenser.
26. The process according to claim 18, wherein the optional solvent recovery unit skid 4 comprises at least one equipment items selected from the group consisting of an activated carbon adsorption package, a regeneration condenser, a solvent/water decanter, a solvent return pump, and a water return pump.
27. The process according to claim 18, further comprising an oxygen-from-the-air supply unit used to feed oxygen into the at least one oxidizer of said oxidizer skid 2.
28. The process according to claim 18, further comprising an oxygen supply unit used to feed oxygen into the at least one oxidizer of said oxidizer skid 2.
29. The process according to claim 18, wherein one or more of said skids 1 to 6 are equipped with one or more sensors for monitoring one or more AO-process parameters at said hydrogen peroxide production plant, said sensors being interconnected with one or more first computers at said hydrogen peroxide production plant, said first computers being linked via a communication network to one or more second computers in a control room being remote from said hydrogen peroxide production plant, and wherein said control room is remotely controlling said hydrogen peroxide production plant.
30. The process according to claim 29, wherein said control room remotely controlling said hydrogen peroxide production plant is located at another hydrogen peroxide production site being different from said remotely controlled hydrogen peroxide production plant.
31. The process according to claim 18, wherein said one or more of said skids 1 to 6 are equipped with one or more sensors for monitoring one or more AO-process parameters.
32. The process according to claim 18, wherein one or more of said skids 1 to 6 are equipped with a safety equipment or safety means to allow for automatic safe shutdown.
33. The process according to claim 18, wherein the plant for producing hydrogen peroxide, by an autoxidation process denoted as AO-process, consists of the following skid mounted modules a skid mounted module comprising at least one hydrogenator to hydrogenate the anthraquinone in the working solution, denoted as hydrogenation skid 1; a skid mounted module comprising at least one oxidizer to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as oxidizer skid 2; optionally a skid mounted module configured to compress air, denoted as process air compressor skid 3, to feed oxygen into the at least one oxidizer of the oxidizer skid 2, and when said process air compressor skid 3 is present in said plant, a further skid mounted module configured to recover solvent, denoted as solvent recovery unit skid 4, when oxygen from the air is used to feed oxygen into the at least one oxidizer of said oxidizer skid 2; a skid mounted module configured to extract the hydrogen peroxide from the working solution, denoted as extraction skid 5; and a skid mounted module, denoted as skid 6, comprising at least one means to deliver a hydrogen peroxide solution to a point of use and/or optionally to a storage tank.
34. An autoxidation process for producing hydrogen peroxide, denoted as an AO-process, the process comprising the use of a plant, wherein the plant comprises at least two skid mounted modules selected from the group consisting of: a skid mounted module comprising at least one hydrogenator to hydrogenate an anthraquinone in a working solution, denoted as hydrogenation skid 1; a skid mounted module comprising at least one oxidizer to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as oxidizer skid 2; optionally a skid mounted module configured to compress air, denoted as process air compressor skid 3, to feed oxygen into the at least one oxidizer of the oxidizer skid 2, and when said process air compressor skid 3 is present in said plant, a further skid mounted module configured to recover solvent, denoted as solvent recovery unit skid 4, when oxygen from the air is used to feed oxygen into the at least one oxidizer of said oxidizer skid 2; a skid mounted module configured to extract the hydrogen peroxide from the working solution, denoted as extraction skid 5; and a skid mounted module, denoted as skid 6, comprising at least one means to deliver a hydrogen peroxide solution to a point of use and/or optionally to a storage tank; wherein the plant is a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide of up to 20 kilo tons per year; wherein the plant is located proximal to or on-site of an end user site or a customer site utilizing hydrogen peroxide in an industrial application; wherein the AO-process runs in continuous operation; and wherein the plant does not include at least one of a unit for regeneration of the working solution and a unit for the reactivation of a hydrogenation catalyst.
35. The process according to claim 35, wherein each skid comprises exchangeable equipment items.
36. The process according to claim 35, wherein the plant comprises said hydrogenation skid 1, said oxidation skid 2 and said extraction skid 5, and wherein said hydrogenation skid 1, said oxidation skid 2 and said extraction skid 5, together with any optional skid, are designed as a modular reactor system.
37. The process according to claim 36, wherein the plant is a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide of a range selected from the group consisting of 2-3 kilo tons per year, 3-5 kilo tons per year, 5-7.5 kilo tons per year, 7.5-10 kilo tons per year, 10-12.5 kilo tons per year, and 12.5-15 kilo tons per year.
Description
SHORT DESCRIPTION OF THE DRAWINGS
[0040]
[0041]
DETAILED DESCRIPTION OF THE INVENTION
[0042] In its broadest aspect the present invention provides an industrial technically, operationally and economically feasible plant for the industrial manufacture of hydrogen peroxide, in particular of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process), which plant is an arrangement of skid mounted modules of various reactors, and optionally utilities, conventionally used in an autoxidation process (AO-process) for the manufacture hydrogen peroxide, for example skids for a hydrogenator (hydrogenation skid), an oxidizer (oxidation skid) and means to extract hydrogen peroxide (extraction skid). This arrangement of skid mounted modules is particularly suitable for a modular small-to-medium sized AO-process plant and the arrangement allows for easy assembling and/or exchange of individual equipment parts (modules, skids), simple service and maintenance, simple operations and control. This aspect of the invention will be referred to in the following as modular concept or modular design.
[0043] In more detail the modular plant according to the invention is directed to a plant for production of hydrogen peroxide, in particular of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process), the process comprising hydrogenating an anthraquinone in a working solution, oxidizing the hydrogenated anthraquinone with oxygen to form hydrogen peroxide and extracting the hydrogen peroxide from the working solution, the plant comprising at least one skid mounted module selected from the group consisting of [0044] a skid mounted module comprising at least one hydrogenator (hydrogenation reactor) to hydrogenate the anthraquinone in the working solution, denoted as skid 1 (hydrogenation skid); [0045] a skid mounted module comprising at least one oxidizer (oxidation reactor) oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as skid 2 (oxidizer skid); [0046] optionally a skid mounted module comprising at least one means to compress air (process air compressor), denoted as skid 3 (process air compressor skid), to feed oxygen, in particular oxygen from the air, into an oxidizer of skid 2, and in case of presence of skid 3 a further skid mounted module comprising at least one means to recover the solvent (solvent recovery unit), denoted as skid 4 (solvent recovery unit skid), in particular if oxygen from the air is used to feed oxygen into an oxidizer of skid 2; [0047] a skid mounted module comprising at least one means to extract the hydrogen peroxide from the working solution (extraction unit), denoted as skid 5 (extraction skid); [0048] a skid mounted module, denoted as skid 6, comprising at least one means to deliver hydrogen peroxide solution to the point of use and/or optionally to a storage tank optionally with additional means for adjusting the hydrogen peroxide concentration.
[0049] In brief, the modular plant according to the invention may comprises five main skid mounted modules, a hydrogenator mounted on the skid 1, an oxidizer mounted on the skid 2, a process air compressor mounted on the skid 3, a solvent recovery unit mounted on skid 4 and extraction equipment (means to extract hydrogen peroxide) mounted on skid 5, and a skid mounted module (skid 6) with means for delivery of hydrogen peroxide solution to the point of use and/or optionally to a storage tank. These modules may be mounted on separate individual skids or alternatively it is possible to combine certain modules on the same skid. Thus, the hydrogenator and the oxidizer, for example, may be mounted each on separate skids, a hydrogenation skid 1 and an oxidation skid 2, or alternatively the hydrogenator and the oxidizer may be mounted together on the same skid, the denoted as combined hydrogenation/oxidation skid 1-2. Particularly, this combination option skid 1-2 may be the case where intensified hydrogenation and oxidation reactors are used; hydrogenation and/or oxidation related ancillary equipment then usually may be installed within the same skid 1-2. In case of the extraction skid 5, depending on the size and capacity of the modular AO-process plant, optionally the extraction skid 5 may have an extraction column of smaller size and/or usually just is connectable to at least one, especially larger sized, extraction column. However, normally the extraction column will be too large to fit within the extraction skid 5, and in this case it will carry only ancillary means for the extraction of hydrogen peroxide, but will be connectable to at least one extraction column. Also, it is possible to combine all or part of the any ancillary means normally used in the manufacture of hydrogen peroxide by the AO-process in the same skid, if so wished and if capacity and overall circumstances at a plant site allow.
[0050] Furthermore, some modules may not be required depending on the conditions of the overall autoxidation process (AO-process) and the specific arrangement of the plant. For example in the oxidation step, the hydrogenated working compounds, i.e. the alkylhydroanthraquinones, can be oxidized using (pure) oxygen, air, oxygenated air, or a suitable oxygen containing compound in order to produce hydrogen peroxide and restore the working compound to its original form. Now, skids 3 and 4 would not be necessary if, for example, (pure) oxygen were used in the oxidation step, e.g. in case of a site where oxygen is available in bulk supply, because under such condition and arrangement of a (pure) oxygen supply no process air compressor skid and no solvent recovery skid would be required.
[0051] The terms oxygen or pure oxygen in the present context mean a gaz essentially consisting of oxygen, usually oxygen of technical grade or oxygen with a purity of bulk supply oxygen as normally understood by those skilled in the art, with only minor other gaz constituents, and in a composition compatible with for example the catalyst and working solution. Thus, normally such pure oxygen will have a purity of at least 90 vol.-%, preferably of at least 95 vol.-%, more preferably of at least 97 vol.-%, and most preferably of at least 99 vol.-%. In case the oxygen purity is of at least 90 vol.-%, then there is no need for a Process Air Compressor skid and no need for a Solvent Recovery skid.
[0052] A list of the major equipment items to be included within each skid of a plant for production of hydrogen peroxide, especially of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) according to the present invention is given hereunder, e.g. the equipment items allocated to each skid, for example: the hydrogenation skid 1, oxidation skid 2, the optional process air compressor skid 3, the optional solvent recovery skid 4, and the extraction skid 5. The meaning of terms used for the typical equipment and utilities for the manufacturing of hydrogen peroxide by the autoxidation process, e.g. terms like hydrogenator, oxidizer, extractor, extraction, catalyst, working solution, hydrogen, oxygen, pure oxygen pure oxygen in bulk supply, air, process air, oxygenated air, and the functioning of such equipment and utilities, is well known to those skilled in the art, as well as for related ancillaries.
[0053] As described, skid 6 comprises at least one means to deliver hydrogen peroxide solution to the point of use and/or storage tank. Normally the produced aqueous hydrogen peroxide solution can be directly delivered from skid 6 to a point of use, but under circumstances it might be useful to collect all or a portion of the crude hydrogen peroxide solution in a storage tank before further delivery to the actual point of use. This may for example be in case of downtime or of reduced consumption by the hydrogen peroxide utilizing application. Or this may be to compensate for downtime or reduced hydrogen peroxide production, e.g. in case of maintenance activities related to the modular hydrogen peroxide AO-process plant. Thus, optionally, the modular plant according to the invention for the production of (aqueous) hydrogen peroxide (solutions) by the autoxidation process (AO-process) may foresee a product storage tank for the storage of produced crude hydrogen peroxide solution. However, this storage tank would not be mounted on a skid, as this product storage tank would be too large to fit on a skid, and so this would normally be built on site. The storage tank, of course, would also be equipped with product delivery pumps, and optionally may also be equipped with additional means for adjusting the hydrogen peroxide concentration, like on skid 6. The person skilled in the art is well aware of any equipment, ancillaries, materials and the like that might be needed to set up, operate and maintain such a storage tank, as well as about related operating conditions.
[0054] Instead of providing a separate analysis skid for the plant, but which may be foreseen if so wished, it is envisaged that the analysis, for example but without limitation, of the hydrogen peroxide solution or the working solution, usually will be done only occasionally as deemed appropriate by the skilled person, in a small section of the porta-cabin housing the control (e.g. mini-DCS) and interlock hardware (e.g. safety PLC), motor control centre (MCC) and operator station. The person skilled in the art is well aware of any equipment, ancillaries, materials and the like that might be needed to set up, operate and maintain such means for the analysis.
[0055] In this aspect of the invention the modular AO-process plant comprises specific safety equipment or safety means (interlock system) to allow for automatic safe shutdown in case of incidents that require interruption of the hydrogen peroxide production for e.g. for safety reasons or other deficiencies with regard to the process or utilities, to the equipment, sensors, computers, communication network and the like. In such case the modular AO-process plant is controlled by a computer which will include a safety PLC (independent protection layer) or hardwired relay based system for the monitoring and automatic safe shutdown of the plant in case of abnormalities (interlock system). In such cases, a beep or cell phone message could be sent to the local operator in charge of the plant, which could then enter the plant at a convenient time (maybe the next day; as the plant can be provided with intermediate product storage, the client or consumer will not be affected) in order to restart the plant safely (e.g. in this case of automatic safe shutdown no remote startup must be foreseen).
[0056] Normally there will also be means for drawing off used working solution from the autoxidation process and means for feeding fresh working solution into the autoxidation process. There is not necessarily a specific separate skid required for such means, which may be integrated on the same or on a different skid as denoted above as skids 1 to 6. For example but without limitation, from time to time (e.g. without limitation periodical like monthly, quarterly or annually) the emptying and replenishing of working solution can be done directly into and from ISO-containers without need for intermittent storage. Despite there is no need for providing a separate skid or module for emptying or replenishing the plant, such equipment may be foreseen if so wished. The person skilled in the art is well aware of any equipment, ancillaries, materials and the like that might be needed to set up, operate and maintain such means for the emptying and/or replenishing of the AO-process plant.
[0057] Despite there is no need for providing a separate skid for intermittent storage of fresh working solution and/or for used working solution, under circumstances it might be useful to collect all or a portion of the used working solution in a storage tank and/or to have fresh working solution ready for use in a storage tank before filling it into the AO-process plant.
[0058] Thus, optionally, the modular plant according to the invention for the production of (aqueous) hydrogen peroxide (solutions) by the autoxidation process (AO-process) may foresee such a storage tank for either at least one or for both, the used working solution and the fresh working solution. However, such a storage tank would generally not be mounted on a skid, as it would be too large to fit on a skid, and so such storage tanks normally would be site-fabricated. The storage tank, of course, would preferably also be equipped with pumps, and optionally may also be equipped with other required ancillary means. The person skilled in the art is well aware of any equipment, ancillaries, materials and the like that might be needed to set up, operate and maintain such a storage tank for the used and/or fresh working solution, as well as about related operating conditions. Alternatively, it will be also possible to engage one or more mobile storage tank or liquid containers, for example a road tanker or a train freight car suited to safely transport large quantities of industrial liquids.
[0059] Analogously, as described above for the analysis equipment, instead of providing a separate a skid mounted module comprising one or more means to operate the skid mounted modules of the AO-process plant, but which may be foreseen if so wished, it is envisaged that the operation and control equipment, materials and ancillaries would also be in the form of a porta-cabin. The person skilled in the art is well aware of any equipment, ancillaries, materials and the like that might be needed to set up, operate and maintain such means for the operation and control of an AO-process plant.
[0060] Optionally the skid mounted modules employed in the context of the present invention may be complemented and/or supplemented by additional installations comprising one or more means for providing utilities and/or other ancillaries commonly employed in the autoxidation process as appropriate.
[0061] In the embodiments of a plant for production of (aqueous) hydrogen peroxide (solutions) by the autoxidation process (AO-process) according to the present invention, the hydrogenation skid 1 normally comprises at least one or more equipment items selected from the group of Hydrogenator, Hydrogen Recycle Compressor, Catalyst Filter, Oxidizer Feed Tank, Oxidizer Feed Pump and Guard Catalyst Bed.
[0062] Herein, the meaning of terms used for said equipment items of the Hydrogenation Skid and functioning of such equipment and of utilities used therein, as well as for related ancillaries, is well known to those skilled in the art.
[0063] For example, the Hydrogenator is understood as reactor or reactor system (hydrogenation unit) for hydrogenating a working solution in the presence of a catalyst, wherein said working solution contains at least one anthraquinone, not malty an alkylanthraquinone, dissolved in at least one organic solvent, to obtain at least one corresponding anthrahydroquinone compound, normally an alkylanthrahydroquinone compound. Next to this main component of the hydrogenation skid, a Hydrogen Recycle Compressor can be included, as well as a Catalyst Filter to avoid transition of potentially abraded catalyst into the oxidizer, the Oxidizer Feed Tank, the Oxidizer Feed Pump and the Guard Catalyst Bed as shown in
[0064] The hydrogenation in the hydrogenator may be performed in a conventional manner with a typical hydrogenation catalyst suited for a process for the manufacture of hydrogen peroxide by the Riedel-Pfleiderer AO-process and its variants. Typical hydrogenating catalysts known for the anthraquinone cyclic process can be used as catalysts in the hydrogenation stage, for instance, such as noble metal catalysts containing one or more noble metals from the series Pd, Pt, Ir, Rh and Ru. The catalysts known for the anthraquinone cyclic process can be in the form of fixed- bed catalysts or in the form of suspended catalysts, suspended catalysts being able to be used both in the form of an unsupported catalyst, e. g. palladium black or Raney nickel, and in the form of a supported suspended catalyst. While other catalytic metals may be used, for the purpose of the invention it was found that hydrogenation catalyst shall preferably comprise palladium (Pd) as the catalytic metal, preferable in combination with silver (Ag), and that such catalysts shall be used in the hydrogenation step. Palladium and palladium/silver catalysts are known to the ordinary skilled artisan, and Pd as well as Pd/Ag-catalysts optimized for the AO-process are described in the state of the art. As an example for a typical Pd/Ag, hydrogenation catalyst composition reference is made to WO 98/15350 (Solvay Interox) which describes a Pd/Ag catalyst composition of 0.5-2.5% by wt. Pd and 0.5-2.5% by wt. Ag, and which is used in a process for the manufacture of hydrogen peroxide by the anthraquinone process.
[0065] The hydrogenator may be operated with a fixed-bed catalyst of a Pd/Ag combination as the catalytic metal. In an alternative variant the hydrogenator may also be operated with a slurry catalyst. The fixed-bed catalyst usually consists of a packing of solid hydrogenation catalyst particles. It is generally desirable that the average diameter of these particles should be in the range of from about 0.2 to 10 mm. In a preferred embodiment of the process according to the invention the catalyst granules in the fixed bed have an average particle diameter of from 1 to 5 mm. Preferably, the catalyst of a Pd/Ag combination displays high initial selectivity and long-term in stability outweighing the higher costs compared to a slurry catalyst. Productivities may be improved and/or costs (carrier/manufacture) may decreased by using lower particle sizes (e.g.1-2 mm).
[0066] In the embodiments of a plant for production of (aqueous) hydrogen peroxide (solutions) by the autoxidation process (AO-process) according to the present invention, the oxidizer skid 2 normally comprises at least one or more equipment items selected from the group of Oxidizer Feed Cooler, Oxidizer, Degasser, Extraction Feed Pump, Off-Gas Condenser and Off-Gas Demister. Herein, the meaning of terms used for said equipment items of the Oxidizer Skid and functioning of such equipment and of utilities used therein, as well as for related ancillaries, is well known to those skilled in the art.
[0067] For example, the Oxidizer is understood as reactor or reactor system (oxidation unit) for oxidizing said at least one anthrahydroquinone compound, normally an alkylanthrahydroquinone compound, resulting from the hydrogenator with oxygen or an oxygen comprising gaz back into the corresponding anthrahydroquinone, normally alkylanthrahydroquinone compound, and thereby to obtain hydrogen peroxide.
[0068] The oxidation step in the Oxidizer is following the previous step of hydrogenating the working compound dissolved in the in the working solution. In the oxidation step, the hydrogenated working compounds, i.e. the alkyrthydroanthraquinones, are oxidized using oxygen, air, oxygenated air, or a suitable oxygen containing compound in order to produce hydrogen peroxide and restore the working compound to its original form. The oxidation may take place in a conventional manner as known for the AO-process. Typical oxidation reactor types known for the anthraquinone cyclic process can be used for the oxidation. Bubble reactors, through which the oxygen-containing gas and the working solution are passed co-currently or counter-currently, are frequently used. The bubble reactors can be free from internal devices or preferably contain internal devices in the form of packing or sieve plates. Oxidation can be performed at a temperature in the range from 30 to 70 C., particularly at 40 to 60 C. Oxidation is normally performed with an excess of oxygen, so that preferably over 90%, particularly over 95%, of the alkyl anthrahydroquinones contained in the working solution in hydroquinone form are converted to the quinone form. For example, the oxidation may be performed in any type of oxidation reactor, e.g. such as CSTRs (continuous stirred tank reactor), but other forms of oxidation reactors may be applied, too. The oxidation reactor preferably has the advantage of being (very) compact and of showing good performance, e.g. in terms of selectivity and productivity. Optionally, the oxidation reactor may have been subjected to protection measures against corrosion, before being placed into the production and/or during the production. In view of the extraction step following the oxidation, water addition may be beneficial already in the mini-AO-process oxidation step.
[0069] The hydrogen peroxide produced in the oxidation step in the Oxidizer is then removed from the working solution, typically by extraction with water, and the remaining working solution containing the alkylanthraquinones in their original form is preferably recycled to the hydrogenation step to again perform the process. Hence, in this preferred embodiment, the process is a loop process. In the embodiments of a plant for production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) according to the present invention, the extraction skid 5 for the means to extract hydrogen peroxide normally comprises at least one or more equipment items selected from the group of Cooler, Coalescer and Hydrogenator Feed Pump, and optionally an Extraction Column and/or being connectable to an Extraction Column. Depending on the size and capacity of the modular AO-process plant the extraction skid 5 may have an extraction column of smaller size and/or alter-natively is connectable to at least one, especially larger sized, extraction column. Normally the extraction column will be too large to fit within the extraction skid 5, and in this case skid 5 will carry only ancillary means for the extraction of hydrogen peroxide, but will be connectable to at least one extraction column. Herein, the meaning of terms used for said equipment items of the Extraction Skid and functioning of such equipment and of utilities used therein, is well known to those skilled in the art, as well as for related ancillaries.
[0070] The Extraction Column is understood as a system for extracting the hydrogen peroxide, which is formed in the Oxidizer, with water from the working solution to result in a crude aqueous hydrogen peroxide solution. The Coalescer is understood as a technological device performing coalescence. A coalescer is primarily used to separate emulsions into their components via various processes and is operating in reverse to an emulsifier.
[0071] In the embodiments of a plant for production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) according to the present invention, the optional process air compressor skid 3 normally comprises at least one or more equipment items selected from the group of Process Air Compressor Package, Suction Air Filter and After Cooler-Condenser. Herein, the meaning of terms used for said equipment items of the Process Air Compressor Skid and functioning of such equipment and of utilities used therein, is well known to those skilled in the art, as well as for related ancillaries.
[0072] In the embodiments of a plant for production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) according to the present invention, the optional solvent recovery unit skid 4 normally comprises at least one or more equipment items selected from the group of Activated Carbon Adsorption Package, Regeneration Condenser, Solvent/Water Decanter, Solvent Return Pump and Water Return Pump. Herein, the meaning of terms used for said equipment items of the Solvent Recovery Skid and functioning of such equipment and of utilities used therein, is well known to those skilled in the art, as well as for related ancillaries.
[0073] Those skilled in the art are also very familiar with the principles of the autoxidation process (AO-process) for the manufacturing of hydrogen peroxide, e.g. besides the typical equipment, ancillaries and utilities for the manufacturing of hydrogen peroxide by the autoxidation process, also the process chemistry, the process operation, analysis and control and the handling of the hydrogen peroxide product, as well as the related ancillary processes, are well known to those skilled in the art. Therefore, the person skilled in the autoxidation process (AO-process) for manufacturing hydrogen peroxide may easily perform such an AO-process in the modular plant according to the invention. This means that also in the modular plant according to the present invention, as described above, in a first step a working compound, for example an anthraquinone, particularly an alkylanthraquinone, which is dissolved in a solvent (e.g. together called working solution) is hydrogenated with elemental hydrogen in the presence of a catalyst. After the hydrogenation of the working compound dissolved in the in the working solution, the next process step of the cyclical mini-AO-process is the oxidation step. In the oxidation step, the hydrogenated working compounds, i.e. the alkylhydroanthraquinones, are oxidized using oxygen, air, oxygenated air, or a suitable oxygen containing compound in order to produce hydrogen peroxide and restore the working compound to its original form. The hydrogen peroxide produced in the oxidation step is then removed from the working solution, typically by extraction with water, and the remaining working solution containing, the alkylanthraquinones in their original form is recycled to the hydrogenation step to again commence the process.
[0074] It was already mentioned above that, depending on the type of oxidizing agent, the modular plant according to the present invention may comprise all the skids 1 to 6 or that alternatively the skids 3 (Process Air Compressor Skid) and 4 (Solvent Recovery Skid) would be void if oxygen or pure oxygen were used as the oxidizing agent.
[0075] Thus, in one embodiment the invention, e.g. in case of using air, oxygenated air or oxygen with a purity of less than 90 vol.-% oxygen, the invention pertains to a plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) comprising an oxygen from the air supply unit used to feed oxygen into an oxidizer of skid 2 and further comprising at least one skid mounted module selected from the group consisting of [0076] a skid mounted module comprising at least one hydrogenator (hydrogenation reactor) to hydrogenate the anthraquinone in the working solution, denoted as skid 1 (hydrogenation skid); [0077] a skid mounted module comprising at least one oxidizer (oxidation reactor) to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as skid 2 (oxidizer skid); [0078] a skid mounted module comprising at least one means to compress air (process air compressor), denoted as skid 3 (process air compressor skid), to feed oxygen, in particular oxygen from the air, into an oxidizer of skid 2, and comprising a further skid mounted module comprising at least one means to recover the solvent (solvent recovery unit), denoted as skid 4 (solvent recovery unit skid); [0079] a skid mounted module comprising at least one means to extract the hydrogen peroxide from the working solution (extraction unit), denoted as skid 5 (extraction skid); [0080] a skid mounted module, denoted as skid 6, comprising at least one means to deliver hydrogen peroxide solution to the point of use and/or optionally to a storage tank optionally with additional means for adjusting the hydrogen peroxide concentration.
[0081] Optionally, also in this variant of the invention, the skid mounted modules employed in the context of the present invention may be complemented and/or supplemented by additional installations comprising one or more means for providing ancillaries and/or utilities commonly employed in the autoxidation process as appropriate.
[0082] In another embodiment the invention, e.g. in case of using oxygen or pure oxygen, e.g. oxygen with a purity of at least 90 vol.-% oxygen, the invention pertains to a plant for production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) comprising a (pure) oxygen supply unit used to feed oxygen into an oxidizer of skid 2 and further comprising at least one skid mounted module selected from the group consisting of [0083] a skid mounted module comprising at least one hydrogenator (hydrogenation reactor) to hydrogenate the anthraquinone in the working solution, denoted as skid 1 (hydrogenation skid); [0084] a skid mounted module comprising at least one oxidizer (oxidation reactor) to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide, denoted as skid 2 (oxidizer skid); [0085] a skid mounted module comprising at least one means to extract the hydrogen peroxide from the working solution (extraction unit), denoted as skid 5 (extraction skid); p1 a skid mounted module, denoted as skid 6, comprising at least one means to deliver hydrogen peroxide solution to the point of use and/or optionally to a storage tank optionally with additional means for adjusting the hydrogen peroxide concentration.
[0086] Optionally, also in this variant of the invention, the skid mounted modules employed in the context of the present invention may be complemented and/or supplemented by additional installations comprising one or more means for providing ancillaries and/or utilities commonly employed in the autoxidation process as appropriate.
[0087] The embodiments of the present invention concerning a modular concept or modular design of a plant for the production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) is particularly suitable to be realized as a hydrogen peroxide production facility which is located at a customer or host site where hydrogen peroxide is consumed in a customer's or in a host site's industrial process, and insofar the modular plant according to the present invention differs from conventional large-to-mega scale plants for the production of hydrogen peroxide, which are usually hydrogen peroxide plants providing for a larger hydrogen peroxide production capacity of at least 30 kilo tons per year, and more usually of at least 40 kilo tons per year.
[0088] As compared to conventional large scale hydrogen peroxide production plants, the modular plant according to the invention is simplified and automated as much as possible in order to allow for being easily and safely operated and remotely controllable, such that it stably runs in continuous operation proximal to or on-site of an end user or hydrogen peroxide customer industrial application site, and such that it can be easily supported and maintained with a minimum need for local (e.g. on customer site) technical and/or physical intervention.
[0089] Surprisingly, it was found that such a modular plant for the hydrogen peroxide production proximal to or on-site of a hydrogen peroxide using customer (host site) may be achieved if the modular plant design and the AO-process therein is sized to a small-to-medium scale hydrogen peroxide production capacity. Thus, the modular plant of the invention is particularly suitable for the manufacture of hydrogen peroxide by the AO-process with a small-to-medium scale production capacity of hydrogen peroxide of up to 20 kilo tons per year (ktpy) i.e. of maximum 20 ktpy. Preferably the modular plant of the invention is designed for a production capacity of hydrogen peroxide of up to 15 kilo tons per year (ktpy), and more preferably with a production capacity of hydrogen peroxide of up to 10 kilo tons per year (ktpy). The abbreviation ktpy in the context of the present invention means the dimension kilo tons per year and relates to metric tons. Further, said small-to-medium-scale hydrogen peroxide production process scale will be referred to in the following as (modular) mini-AO-plant and (modular) mini-AO-process, respectively.
[0090] Consequently, in a preferred embodiment the invention pertains to a plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein the hydrogenation skid 1, oxidation skid 2 and extraction skid 5 together with any optional skid are designed as a modular reactor system, preferably as a compact modular reactor system, which is configured to operate as a small-to-medium scale AO-process with a production capacity of hydrogen peroxide of up to 20 kilo tons per year (ktpy), preferably with a production capacity of hydrogen peroxide of up to 15 kilo tons per year, and more preferably with a production capacity of hydrogen peroxide of up to 10 kilo tons per year (ktpy).
[0091] Another advantage of the (modular) mini-AO-plant according to the present invention is that the modular plant can be designed with or in particular without a reversion unit, e.g. without a permanent reversion unit, which is usually mandatory in plants with large-to-mega scale hydrogen peroxide production capacity.
[0092] Therefore, a further embodiment of the invention is directed to a plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein the hydrogenation skid 1, oxidation skid 2 and extraction skid 5 together with any optional skid are designed as a modular reactor system, preferably a compact modular reactor system, which is configured to operate without a reversion (regeneration) unit, preferably configured to operate without a permanent reversion (regeneration) unit, and wherein the working solution and/or the catalyst are replaced and/or treated for regeneration or reactivation only intermittently or periodically with a low frequency as defined below.
[0093] Preferably, in this variant of the invention without a reversion (regeneration) unit, in particular without a permanent reversion unit, the modular reactor system is also configured to operate as a small-to-medium scale AO-process with a production capacity of hydrogen peroxide of up to 20 kilo tons per year, preferably with a production capacity of hydrogen peroxide of up to 15 kilo tons per year, and more preferably with a production capacity of hydrogen peroxide of up to 10 kilo tons per year. Any of the herein given minimum and/or maximum values for the production capacity or any of the before given ranges for the production capacity are applicable and combinable with this variant of the invention without a (permanent) reversion (regeneration) unit.
[0094] In particular, the reactor system is configured to operate without a (permanent) reversion (regeneration) unit for continuous or permanent reversion of the working solution. The only intermittently or periodically replacing and/or treating for regeneration or for reactivation of the working solution and/or the catalyst needs to be performed only with a low frequency, e.g. only after periods of a certain duration, e.g. of some weeks or months. Preferably, the working solution and/or the catalyst are replaced and/or treated for regeneration or reactivation only intermittently or periodically with a low frequency of only about monthly periods, preferably only after periods of at least 3 months in the loop of the AO-process. The reactor system is preferably almost completely closed, e.g. meaning that only minimum needed in- and/or outlets are forseen for perfuming the AO-loop process of hydrogenation, oxidation and the extraction of the aqueous hydrogen peroxide product.
[0095] The modular plant according to the invention is very suitable for performing a mini-AO-process for the manufacture of hydrogen peroxide which is automated to such an extent that it can be operated such that very little attention and support is required, in particular with regard to the reversion of the working solution and/or the regeneration of the hydrogenation catalyst. The modular plant according to the invention allows for a mini-AO-process for the manufacture of hydrogen peroxide to be operated such that the working solution and/or the catalyst are only intermittently or periodically with a low frequency, as described above, replaced or treated for regeneration or reactivation. This aspect of the invention is referred to as intermittent, periodical or low frequency reversion and/or regeneration. Thus, in contrast to the conventional plants for the industrial manufacture of hydrogen peroxide which comprise a permanent reversion unit for continuous reversion of the working solution during the AO-process, the modular plant according to the present invention is preferably simplified without the need to include such a permanent reversion unit. Therefore, when performing the AO-process in a modular plant according to the present invention the working solution is reversed and/or the catalyst is regenerated only intermittently or periodically with low frequency, e.g. at a point in time when the production of a predefined quantity of hydrogen peroxide is reached, when the production efficiency drops below a predefined threshold value of a minimum required production efficiency, and/or when a the quantity of by-products exceeds a certain predefined quantity. Thus, when using a modular plant according to the present invention for the manufacture of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, the working solution is normally replaced, by a fresh working solution or by a refreshed working solution, e.g. a working solution withdrawn from the reactor system and treated for reversion before refilling the reactor with said refreshed working solution, only intermittently when the before mentioned event occurs.
[0096] The working solution is then regenerated in separate equipment for the reversion of the working compounds contained in the working solution. This reversion of the working solution may be performed, for instance, at a different site in the equipment of another hydrogen peroxide production plant, e.g. in the respective regeneration equipment of a similar or preferably a larger scale hydrogen peroxide production plant. Alternatively, the working solution may be regenerated in separate mobile regeneration equipment for the reversion of the working compounds contained in the working solution, e.g. in a mobile regeneration unit that is used on demand or as appropriate in a number of different locations where a small to medium hydrogen peroxide manufacturing process according to the AO-process is performed. Another option is to intermittently or periodically perform the regeneration of the working solution under particular conditions in the main equipment of the small-to-medium hydrogen peroxide manufacturing process according to the AO-process itself.
[0097] Normally, within the modular plant of the invention the mini-AO-process for the manufacture of hydrogen peroxide can be performed such that the working solution and/or the catalyst are only periodically replaced for regeneration or reactivation, e.g. usually the AO-process may be operated within the modular plant of the invention for periods of several weeks, preferably months without replacement of the working solution for regeneration (reversion) or reactivation of the catalyst. The periodical replacement of the working solution and of the catalyst are independent front each other, but both may reasonably also be replaced at the same time or at different times or after the same or different periods of operation. Preferably, the reversion is only intermittently performed after a continuous operation period of the modular reactor system (modular plant) of at least 3 months, e.g. the working solution is normally replaced, by a fresh working solution or by a refreshed working solution, e.g. a working solution withdrawn from the modular reactor system and treated for reversion before refilling the modular reactor system with said refreshed working solution, only after periods of at least 3 months operation in the loop of the AO-process.
[0098] For example, a variant of the present invention is directed to a modular plant wherein the hydrogenation skid 1, oxidation. skid 2 and extraction skid 5 together with any optional skid are designed as a modular reactor system, preferably as a compact modular reactor system, which modular plant is configured to operate without a reversion (regeneration) unit, preferably configured to operate without a permanent reversion (regeneration) unit, wherein the working solution and/or the catalyst are replaced and/or treated for regeneration or reactivation only intermittently or periodically after periods of at least 3 months in the loop of the AO-process steps of [0099] (a) hydrogenation of a working solution in the hydrogenation skid 1 (hydrogenator) in the presence of a catalyst, wherein said working solution contains at least one alkylanthraquinone dissolved in at least one organic solvent, to obtain at least one corresponding alkylanthrahydroquinone compound; and [0100] (b) oxidation of said at least one alkylanthrahydroquinone compound in the oxidizer skid 2 (oxidizer) to obtain hydrogen peroxide; and [0101] (c) extracting the hydrogen peroxide formed in the oxidation skid 2 in an extraction skid 5.
[0102] In particular, this embodiment of a modular plant is configured to operate without a reversion (regeneration) unit, preferably configured to operate without a permanent reversion (regeneration) unit, as a small-to-medium scale AO-process with a production capacity of hydrogen peroxide of up to 20 kilo tons per year, preferably with a production capacity of hydrogen peroxide of up to 15 kilo tons per year, and more preferably with a production capacity of hydrogen peroxide of up to 10 kilo tons per year; and in very preferred embodiments any of the above given maximum values for the production capacity or any of the above given ranges for the production capacity are applicable and combinable with this variant of the invention without a (permanent) reversion (regeneration) unit.
[0103] Depending on the type of working solution and/or catalyst, and the particular design and capacity of the modular mini-AO-plant, the mini-AO-process may be so robust that it may be operated within the modular plant of the invention even for periods of individually at least 4, 5, 6, 7, 8, 9, 10, 11 or 12 months without replacement of the working solution for regeneration (reversion) or reactivation of the catalyst. According to this variant of the invention, the working solution and/or the catalyst (contained therein for the purpose of producing hydrogen peroxide by the AO-process) are replaced and/or treated for regeneration or reactivation only periodically after periods of at least 6 month, preferably at least 9 months, and more preferred at least 12 months.
[0104] For example, usually, in practice the continuous working period may be individually from 3-4 months, 3-5 months, 3-6 months, 3-7 months, 3-8 months, 3-9 months, 3-10 months, 3-11 months, 3-12 months; 4-5 months, 4-6 months, 4-7 months, 4-8 months, 4-9 months, 4-10 months, 4-11 months, 4-12 months; 5-6 months, 5-7 months, 5-8 months, 5-9 months, 5-10 months, 5-11 months, 5-12 months; 6-7 months, 6-8 months, 6-9 months, 6-10 months, 6-11 months, 6-12 months; 7-8 months, 7-9 months, 7-10 months, 7-11 months, 7-12 months; 8-9 months, 8-10 months, 8-11 months, 8-12 months; 9-10 months, 9-11 months, 9-12 months; 10-11 months, 10-12 months or 11-12 months.
[0105] According to a further aspect of the invention, an industrial technically, operationally and economically very suitable and flexible, optionally also remotely controllable, modular plant design is described related to a small-to-medium scale hydrogen peroxide production capacity, in which modular plant a mini-AO-process may be operated with a maximum production capacity of up to 20 ktpy. Preferably the modular plant design is sized to a mini-AO-process with an even lower maximum production capacity of up to 15 ktpy (kilo tons per year). Usually, the modular plant design according to the invention is sized to operate a mini-AO-process plant with a capacity in the range of 2 to 15 ktpy. Any of the before given minimum and/or maximum values for the production capacity or any of the before given ranges for the production capacity are applicable and combinable with the variant of the invention without a (permanent) reversion (regeneration) unit.
[0106] In a preferred embodiment the present invention is therefore directed to a modular plant fir production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein the hydrogenation skid 1, oxidation skid 2 and extraction skid 5 together with any optional skid are designed as a modular reactor system, preferably as a compact modular reactor system, which is configured to operate as a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide in the range of 2 to 15 ktpy, preferably in the range of 2 to 10 ktpy.
[0107] In a more preferred variant of this embodiment of the invention the modular plant for production of hydrogen peroxide, preferably of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) is characterized in that the hydrogenation skid 1, oxidation skid 2 and extraction skid 5 together with any optional skid are designed as a modular reactor system, preferably as a compact modular reactor system, which is configured to operate as a small-to-medium scale AO-process plant with a production capacity of hydrogen peroxide in any range selected from 2-3 ktpy, 3-5 ktpy, 5-7.5 ktpy, 7.5-10 ktpy, 10-12.5 ktpy, or 12.5-15 ktpy, preferably in any range selected, from 2-3 ktpy, 3-5 ktpy, 5-7.5 ktpy or 7.5-10 ktpy.
[0108] For example, the modular plant for production of (aqueous) hydrogen peroxide (solutions) by the autoxidation process (AO-process) may be designed such that the hydrogenation skid 1, oxidation skid 2 and extraction skid 5 together with any optional skid as, in particular a compact modular reactor system, can be configured to operate as a small to medium scale AO-process with a production capacity in a flexible manner for a variety of any other ranges within said capacity scope, e.g. to provide a capacity which best fits to the local needs where the process is operated. Thus, as an example and without limitation, possible capacity ranges are from 2-5 ktpy, 2-6 ktpy, 2-7 ktpy, 2-8 ktpy, 2-9 ktpy, 2-10 ktpy, 2-11 ktpy, 2-12 ktpy, 2-13 ktpy, 2-14 ktpy, 2-15 ktpy; 3-6 ktpy, 3-7 ktpy, 3-8 ktpy, 3-9 ktpy, 3-10 ktpy, 3-11 ktpy, 3-12 ktpy, 3-13 ktpy, 3-14 ktpy, 3-15 ktpy; 4-6 ktpy, 4-7 ktpy, 4-8 ktpy, 4-9 ktpy, 4-10 ktpy, 4-11 ktpy, 4-12 ktpy, 4-13 ktpy, 4-14 ktpy, 4-15 ktpy; 5-6 ktpy, 5-7 ktpy, 5-8 ktpy, 5-9 ktpy, 5-10 ktpy, 5-11 ktpy, 5-12 ktpy, 5-13 ktpy, 5-14 ktpy, 5-15 ktpy; 6-7 ktpy, 6-8 ktpy, 6-9 ktpy, 6-10 ktpy, 6-11 ktpy, 6-12 ktpy, 6-13 ktpy, 6-14 ktpy, 6-15 ktpy; 7-8 ktpy, 7-9 ktpy, 7-10 ktpy, 7-11 ktpy, 7-12 ktpy, 7-13 ktpy, 7-14 ktpy, 7-15 ktpy; 8-9 ktpy, 8-10 ktpy, 8-11 ktpy, 8-12 ktpy, 8-13 ktpy, 8-14 ktpy, 8-15 ktpy; 9-10 ktpy, 9-11 ktpy, 9-12 ktpy, 9-13 ktpy, 9-14 ktpy, 9-15 ktpy; 10-11 ktpy, 10-12 ktpy, 10-13 ktpy, 10-14 ktpy, 10-15 ktpy; 11-12 ktpy, 11-13 ktpy. 11-14 ktpy, 11-15 ktpy; 12-13 ktpy, 12-14 ktpy, 12-15 ktpy; 13-14 ktpy, 13-15 ktpy; 14-15 ktpy.
[0109] In a preferred modular plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) the modular plant according to the invention provides for a production capacity of hydrogen peroxide of 2,000 to 10,000 metric tons per year. Typically, the size of a plant for the manufacture of hydrogen peroxide depends on the production capacity. For example, within the preferred design range between 2 and 10 ktpy a plant of 3 ktpy capacity will be much smaller than a 10 ktpy plant. Therefore, in a more preferred embodiment of the invention, e.g. for economic reasons, the design of the mini-AO-process pertains to manufacture of hydrogen peroxide by the AO-process or to mini-AO-plants with narrower capacity ranges, as for instance, 2-3 ktpy, 3-5 ktpy, 5-7.5 ktpy or 7.5-10 ktpy. Similarly, also for higher capacities the more narrow capacity ranges are preferred, as for instance, 10-12.5 ktpy, 12.5-15 ktpy.
[0110] Any of the before given minimum and/or maximum values for the production capacity or any of the before given ranges for the production capacity are applicable and combinable with the variant of the invention without a (permanent) reversion (regeneration) unit.
[0111] In yet a further aspect the present invention provides an industrial technically, operationally and economically very suitable and flexible modular plant design for a remotely controllable, small-to-medium scale hydrogen peroxide production capacity, wherein it is feasible to remotely control the mini-AO process and to automate the mini-AO process to such an extent that it can be easily and safely operated by remote control, and such that very little local attention and support is required. This aspect of the invention will be referred to in the following as remote control. This aspect of the invention is combinable with any other embodiment or variant of the present invention as described herein.
[0112] Accordingly, in this aspect the present invention relates to a modular plant design for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein one or more of said skids 1 to 6 are equipped with one or more sensors for monitoring one or more AO-process parameters at the hydrogen peroxide production plant, said sensors being interconnected with one or more first computers at the hydrogen peroxide production plant, said first computers being linked via a communication network to one or more second computers in a control room being remote from the hydrogen peroxide production plant, and wherein said control room is remotely controlling said hydrogen peroxide production plant.
[0113] The control board of the control room is preferably connected online to a remote control board which may be located on another facility. This allows operating several modular hydrogen peroxide production plants remotely from one single control room. Thus, the control room for remotely controlling the modular hydrogen peroxide production plant according to the present invention may be located at any other suitable site which is different and distant from said remotely controlled modular hydrogen peroxide production plant. Usually, this control room will be located or centralized where appropriate computer equipment can be installed and connected to a communication network, and where the remote control of the hydrogen peroxide production can be optimized and maintained in more practical and economical manner than at the modular production plant itself. At such a different hydrogen peroxide production site normally also staff is available which is optimally trained and experienced regarding the manufacture of hydrogen peroxide by the AO-process and capable to remotely control said distant hydrogen production site, and either to remotely intervene, for instance via the communication network or via phone call or e-mail and the like, or to organize appropriate local intervention at the remotely controlled modular hydrogen peroxide production plant in case of need, for instance by a local operator or by sending dedicated and experienced technical support staff or service technicians.
[0114] The remote control is in particular very suitable for controlling one or more modular hydrogen peroxide production plants according to the present invention with a small-to-medium hydrogen peroxide production scale from a distance. Therefore, in a variant of this remote control aspect the invention also pertains to a plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein the control room remotely controlling the modular hydrogen peroxide production plant is located at another hydrogen peroxide production site being different from said remotely controlled modular hydrogen peroxide production plant, preferably at another hydrogen peroxide production site with a larger scale of hydrogen peroxide production capacity than in said remotely controlled modular hydrogen peroxide plant, and more preferably with a scale of hydrogen peroxide production capacity of at least 30 kilo tons per year, more preferably of at least 40 kilo tons per year, at that larger scale hydrogen peroxide production site.
[0115] The sensors on the one or more skids or on other ancillary means are normally part of a monitoring system conventionally used in the art for monitoring the performance of a hydrogen peroxide manufacturing plant which runs under the AO-process. Therefore, the skids being equipped with one or more sensors for monitoring one or more AO-process parameters usually are those of the main AO-process such as the hydrogenation unit (hydrogenator), an oxidation unit (oxidizer), and an extraction unit (means to extract hydrogen peroxide), or any other obligatory or optional unit of the main AO-process. The skids being equipped with one or more sensors may also be any unit of any ancillary process unit as described herein. The equipment and/or means involved in the manufacture of hydrogen peroxide according to the AO-process, for example but without limitation, may be one or several equipment selected from pumping systems, valves, pipes, vessels, compressors, heating and cooling system, outlets, means for providing power and means for measuring the pressure, temperature, quantity, flow rate, density, viscosity, catalyst activity, acidity, purity, concentration, the hydrogen peroxide productivity or other process parameters relevant for the production of hydrogen peroxide according to the AO-process. There may be also means, as appropriate, for monitoring electric current, voltage and the like.
[0116] The one or more sensors for monitoring AO-process parameters may be of any suitable type, and are in particular those already commonly used in AO-processes for steering the complete hydrogen peroxide production cycle, or any individual or combined AO-process steps. In a variant of the invention, these sensors may be those as commonly used in large-to-mega scale hydrogen production plants or processes. Or in another variant, the sensors may be modified or specifically adapted to the small-to-medium scale hydrogen peroxide production plant or processes. In yet another variant of the modular plant designed for a mini-AO-process according to the invention, a suitable combination of those commonly used in used in large-to-mega scale hydrogen production and those modified or specifically adapted to the small-to-medium scale hydrogen peroxide production, may be involved.
[0117] The one or more sensors may be suited and employed for monitoring AO-process parameters, for example but without limitation, such as pressure, temperature, quantity, flow rate, density, viscosity, catalyst activity, acidity, purity, concentration, hydrogen peroxide productivity or other process parameters relevant for the production of hydrogen peroxide according to the AO-process. A sensor or a combination of sensors may be suited to directly monitor or measure a parameter relevant for the production of hydrogen peroxide according to the AO-process, or the sensor or a combination of sensors may indirectly monitor or measure other data or a variety of other data, and then the parameter relevant for steering the production of hydrogen peroxide according to the AO-process is calculated from said monitored or measured data. Furthermore, a camera or a variety of cameras or other optical equipment to measure optical effects may be used in addition to monitor, measure and/or survey the AO-process, its equipment and means, or parameters, respectively.
[0118] Accordingly, in this aspect of the invention, the modular plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) is designed such that one or more of said skids 1 to 6 are equipped with one or more sensors for monitoring one or more AO-process parameters such as pressure, temperature, quantity, flow rate, density, viscosity, catalyst activity, acidity, purity, concentration, hydrogen peroxide productivity or other process parameters relevant for the production of hydrogen peroxide according to the AO-process.
[0119] According to a further aspect of the invention, the modular plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) is designed such that one or more of said skids 1 to 6 are equipped with a safety equipment or safety means to allow for automatic safe shutdown, preferably a safety PLC (independent protection layer) or hardwired relay based system for the monitoring and automatic safe shutdown (interlock system).
[0120] Another aspect of the present invention is to provide a modular plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process), optionally for a remotely controlled, AO-process for the production of hydrogen peroxide, which modular plant is technically, operationally and economically feasible and designed to operate as a small-to-medium scale hydrogen peroxide production plant preferably on-site of a hydrogen peroxide using customer (host site). The modular plant for the manufacture of hydrogen peroxide by the AO-process according to the invention, optionally under remote control, particularly allows for installing and operating a hydrogen peroxide production plant which is located proximal to or on-site of an end user site or customer site utilizing the hydrogen peroxide an industrial application. Preferably, this end user or customer site is a site with an industrial application of hydrogen peroxide selected from pulp and paper industry or the textile industry, or the mining industry or sites with environmental applications.
[0121] Consequently, the invention also pertains to a plant for production of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, by the autoxidation process (AO-process) wherein the modular hydrogen peroxide production plant is located proximal to or on-site of an end user site or a customer site utilizing the hydrogen peroxide in an industrial application, preferably proximal to or on-site of an end user or customer site with an industrial application of hydrogen peroxide selected from pulp and paper industry or the textile industry, or the mining industry or sites with environmental applications.
[0122] Furthermore, generally no distillation of hydrogen peroxide is required, e.g. the modular AO-process plant for the manufacture of hydrogen peroxide, particularly of aqueous hydrogen peroxide solutions, doe not comprise a distillation unit and the crude low concentration hydrogen peroxide is ready to be utilized in the customers' application. This is an advantage of the production of hydrogen peroxide on-site of a hydrogen peroxide consuming end user (customer), because the modular AO-process plant can avoid the distillation which is usually performed in the large-scale plants for converting the hydrogen peroxide into a more suitable concentrated form for transportation reasons. For example, the hydrogen peroxide concentration in conventional large-scale process is usually 40%, distilled to and transported with a concentration from 50 to 70%. Contrary, the target for the manufacture of hydrogen peroxide in the modular AO-process according to the invention is a concentration of 10-15% hydrogen peroxide.
[0123] Normally, the modular plant according to the invention for the manufacture of hydrogen peroxide by the AO-process, optionally under remote control, is particularly suited for being operated in a way such that from the extraction unit at least a portion of an aqueous solution of hydrogen peroxide is delivered to a site of use that is proximal to the modular hydrogen peroxide production plant, preferably proximal to the extraction skid of said modular hydrogen peroxide production plant. Ideally, in this variant of the modular hydrogen peroxide production plant according to the invention the aqueous hydrogen peroxide solution is delivered as an aqueous hydrogen peroxide solution containing a predetermined concentration of hydrogen peroxide which is suitable for being directly utilized in the specified industrial application of the site of use.
[0124] Thus, the modular hydrogen peroxide production plant according to the invention for the manufacture of hydrogen peroxide by the AO-process may deliver a crude hydrogen peroxide solution in a concentration ready for use in an industrial application is provided. The resulting crude hydrogen peroxide solution is readily suitable for its use at the host site, e.g. as bleaching agent in the pulp and paper industry or the textile industry host site, or in a site with mining and environmental applications. Thus, the hydrogen peroxide concentration in the aqueous solutions resulting from the extraction step according the invention can be specifically adjusted to the end user needs at the host (satellite) site, and the concentration may be in the range of up to 15 percent, preferably in the range of 2-15 percent, more preferably 5-15 percent, and most preferred in the range of 10-15 percent. Other suitable ranges of the crude hydrogen peroxide solution resulting from the mini-AO-process according to the invention may be from 2-5 percent, 2-6 percent, 2-7 percent, 2-8 percent, 2-9 percent, 2-10 percent, 2-11 percent, 2-12 percent, 2-13 percent, 2-14 percent, 2-15 percent; 3-6 percent, 3-7 percent, 3-8 percent, 3-9 percent, 3-10 percent, 3-11 percent, 3-12 percent, 3-13 percent, 3-14 percent, 3-15 percent; 4-6 percent, 4-7 percent, 4-8 percent, 4-9 percent, 4-10 percent, 4-11 percent, 4-12 percent, 4-13 percent, 4-14 percent, 4-15 percent; 5-6 percent, 5-7 percent, 5-8 percent, 5-9 percent, 5-10 percent, 5-11 percent, 5-12 percent, 5-13 percent, 5-14 percent, 5-15 percent; 6-7 percent, 6-8 percent, 6-9 percent, 6-10 percent, 6-11 percent, 6-12 percent, 6-13 percent, 6-14 percent, 6-15 percent; 7-8 percent, 7-9 percent, 7-10 percent, 7-11 percent, 7-12 percent, 7-13 percent, 7-14 percent, 7A-15 percent; 8-9 percent, 8-10 percent, 8-11 percent, 8-12 percent, 8-13 percent, 8-14 percent, 8-15 percent; 9-10 percent, 9-11 percent, 9-12 percent, 9-13 percent, 9-14 percent, 9-15 percent; 10-11 percent, 10-12 percent, 10-13 percent, 10-14 percent, 10-15 percent; 11-12 percent, 11-13 percent, 11-14 percent, 11-15 percent; 12-13 percent, 12-14 percent, 12-15 percent; 13-14 percent, 13-15 percent, or 14-15 percent.
[0125] The modular AO-process plant, in particular the mini-AO-process plant, of the present invention can be operated as a decentralized satellite plant of a central mother plant for the production of hydrogen peroxide, whereby this satellite plant may be located at any, even remote industrial or end user site with the only precondition that at this facility or satellite site hydrogen and other common utilities are readily available for the mini-AO-process. Thus, the mini-AO-process plant can be operated in a decentralized manner as a satellite plant distant, even far distant from a central large-scale mother plant. Therefore, at the satellite plant no facilities or means are required to continuously and simultaneously regenerate (reverse) the working solution and/or to reactivate the hydrogenation catalyst during the AO-process. At the time, e.g., after the above mentioned periods of continuous operation of the mini-AO-process the working solution and/or the catalyst are withdrawn from the satellite plant and replaced by a fresh or reversed working solution, or the catalyst is replaced by a fresh or reactivated catalyst, respectively. The working solution and/or the catalyst withdrawn from the satellite plant then is transported to the central mother plant for the purpose of regeneration (reversion) or reactivation, respectively.
[0126] Next to the essential equipment of the modular AO-process plant according to the invention as described above, the modular plant may also comprise a number of typical ancillary equipment. (e.g. working solution acidity control; hydrogen facility available at remote/satellite site). However, according to the concept of a simplified modular, preferably decentralized and/or remote satellite AO-process plant located at an end user site, the number of ancillary equipment is kept as few as possible and usually is limited to the minimum need for continuously operating the AO-process in the modular and/or satellite plant as simple as possible but also as robust and stable over periods as indicated above without too many physical or technical interventions at the modular and/or satellite plant during said periods.
[0127] Such a plant according to the present invention comprising parts assembled in several skids has many advantages. For example, the skids can be pre-assembled and tested in a factory; thus, they are a kind of off-shelf product, and need only be mounted on-site. This saves time. It is also much easier to dismount specific skids for maintenance, repair of or substitution by skids comprising parts with the same function but improved performance, or with lower or higher output. There are also improvements in safety: for example, as explained above, no hazardous distillation of hydrogen peroxide and no transportation of highly concentrated hydrogen peroxide solutions are required. The capacity of the plant can be expanded by adding modules. Preferably, the skids have sea container size thus allowing for the easy transport of modules.
[0128] Often, the skid structure is a painted steel frame on which all equipments are fixed; they are designed for outdoor installation. Panels, doors and roofs, if fixed on the external structure of the skid, imply that the external skid dimensions exceed the standard sea container dimensions. If necessary, such skids are prefabricated and panels, doors and the roof, respectively, are assembled to the skids on site. The skids may be anchored on an existing concrete slab or by or on specific foundations.
[0129] The advantage of skids is, for example, that they are manufactured, piped, wired and assembled together before shop testing. It is preferred if they are constructed such that the interfaces between the skids are minimized and that all parts in the respective skid are accessible as easily as possible for maintenance, inspection or repair.
[0130] A further advantage of the skids is the safety aspect, a reliable hydrogen peroxide production for 24 h and 7 days a week of crude purity hydrogen peroxide solution ready for use.
[0131] As a particular advantage the present invention provides a modular plant for carrying out an AO-process for the manufacture of hydrogen peroxide, particularly a mini-AO-process, as described above, which plant can be automated to such an extent that it can be operated by remote control in a way that requires very little local attention and support at the hydrogen peroxide site, and therefore is suitable as a hydrogen peroxide plant located proximal to or on a customer site or any other host site.
[0132] The modular mini-AO-plant according to the present invention has the advantage that it is compact, since a couple of equipment and process steps which are performed in conventional AO-processes have been eliminated or are now performed in simpler equipment, or are now performed in a more economically and technically feasible manner remotely in a distant large to mega-scale mother plant which provides optimized facilities and skilled staff, and from where optionally also the process parameters can be remotely controlled. It is noted that the mini-AO-plant according to the present invention most preferably does not comprise a unit for (permanent) reversion (regeneration) of the working solution or a unit the reactivation of the reactivation catalyst. In a preferred embodiment of the invention, therefore, said distant large to mega-scale mother plant shall provide central reversion unit and process for the periodical regeneration of the working solution and/or facilities for the periodical reactivation of the hydrogenation catalyst of the satellite mini-AO plant.
[0133] The described modular AO-process plant according to the present invention has the advantage that it can deal adequately with specific needs of an end user with regard to the use of hydrogen peroxide solutions, e.g. the required amounts at given times of production, the concentration and quality thereof, in its own industrial processes, while at the same lime the modular AO-process plant according to the invention by focus on the essential requirements at the end user site, requires fewer pieces of equipment, less management attention, and less maintenance when compared with conventional large-scale hydrogen peroxide production plants. Thus, with the present invention, an efficient modular hydrogen peroxide AO-process plant is provided which is economically feasible, even at small-to-medium scale industrial hydrogen peroxide manufacturing capacity. Therefore, the present invention constitutes a considerable improvement over the known processes to produce hydrogen peroxide, and in particular aqueous hydrogen peroxide solutions readily suitable for the end users' industrial application.
[0134] While the invention has been described with reference to details of the illustrated embodiment, these details are not intended to limit the scope of the invention as defined in the appended claims.
[0135] Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.