Patent Application
20220396481
This disclosure relates to non-aqueous hydrogen peroxide solutions such as alcohol solutions and methods of manufacturing the non-aqueous hydrogen peroxide solutions.
Hydrogen peroxide (H2O2) is a widely-used compound that finds many industrial and laboratory applications as an oxidizer, bleaching agent, antimicrobial and the like. Peroxide compounds such as H2O2 are characterized by an unstable oxygen-oxygen single bond from which peroxide compounds derive their reactivity and utility. Hydrogen peroxide is commercially-available in aqueous solution, ranging for example, from about 30 wt % in water to about 70 wt % in water. Even higher concentrations of hydrogen peroxide are available under strict regulatory provisions, due to their high reactivity.
Despite the wide range of applications for hydrogen peroxide solutions, the high concentration of water in current commercial products may prevent their use for certain functions in which water is undesirable. For example, high concentration of water can have an undesirable impact such as, for example, solubility issues, byproduct formations, or separation processes. For example, in a Hydrogen Peroxide Propylene Oxide (HPPO) process, where hydrogen peroxide reacts with propylene to form propylene oxide, initially having high concentration of water will lead to a higher amount of undesired byproduct propylene glycol from the reaction between propylene oxide and water. Therefore, there is a need for non-aqueous solutions of hydrogen peroxide that can be used in applications for which aqueous hydrogen peroxide is undesirable, and there is a need for methods of manufacturing such non-aqueous hydrogen peroxide solutions.
This disclosure provides new hydrogen peroxide solutions and processes for making or manufacturing the hydrogen peroxide solutions, in which the water in an aqueous hydrogen peroxide solution is replaced or largely replaced by a non-aqueous solvent such as an alcohol. Any alcohol, for example tert-butyl alcohol (TBA), which can form an azeotropic mixture with water can be used. The disclosed process provides a solution of hydrogen peroxide in the non-aqueous solvent such as an alcohol, in which the water content of the solution can be very low, for example, less than 1 wt %. Such solutions may be useful in applications which would derive benefit from the presence of lower concentrations of amounts of water.
Therefore, there is provided a method of forming a hydrogen peroxide solution, the method comprising: combining an non-aqueous solvent and an aqueous hydrogen peroxide solution to form a first mixture; and removing water from the first mixture to obtain an non-aqueous solvent-based hydrogen peroxide solution. In embodiments, an alcohol, for example tert-butyl alcohol (TBA), can be used as the non-aqueous solvent.
The use of TBA allows integration of TBA sources and the processes which use the non-aqueous solvent-based hydrogen peroxide solution. The TBA used can be recycled back to the first process which already has a system in place for TBA separation and purification. For example, this can be realized in an integration of a Propylene Oxide tert-butyl alcohol (POTBA) plant and an HPPO plant. TBA from the POTBA plant is used to make the TBA-H2O2 solution with low water concentrations which then is fed to the HPPO plant. The TBA separated from the HPPO plant is recycled back to the POTBA plant for separation and purification. In this scheme, the HPPO plant does not need a TBA purification and recycling system, thus reducing the capital investment.
In embodiments, this disclosure also provides a continuous process for making a non-aqueous hydrogen peroxide solution, the process comprising:
In some embodiments, this continuous process may further comprise the step of:
This continuous process may further comprise the step of:
In further embodiments, this disclosure also provides a chemical facility which can perform the continuous process, the chemical facility comprising:
In some embodiments, the separation unit of this chemical facility may be configured to return at least a portion of the non-aqueous solvent fraction into the fresh non-aqueous solvent source of step a).
This chemical facility may further comprise:
In a further aspect, this disclosure also provides a method of making a hydrogen peroxide solution, the method comprising:
These and other aspects, embodiments, and features of the processes, methods, facilities, and compositions are described more fully in the Detailed Description and claims and further disclosure such as the Examples provided herein.
Aspects of this disclosure provide for non-aqueous hydrogen peroxide solutions such as alcohol solutions, and processes for manufacturing these non-aqueous hydrogen peroxide solutions. Many aspects and examples presented in this disclosure are described in terms of alcohol solutions of hydrogen peroxide, for example, tert-butyl alcohol (TBA or tertiary-butyl alcohol) solutions. However, this disclosure is also applicable to other non-aqueous solvents, for example, other non-aqueous solvents which can form an azeotrope with water.
The term “non-aqueous” solvent is used in this disclosure rather than “anhydrous” solvent to reflect that the solvents used according to this disclosure can contain small amounts or trace amounts of water. Therefore, while anhydrous solvents can be used according to the disclosure, the solvents do not have to be strictly anhydrous.
In some embodiments, the formation of a hydrogen peroxide solution in alcohol can be carried out by first combining an aqueous hydrogen peroxide solution with an alcohol such as TBA, to form a mixture of TBA, hydrogen peroxide, and water. This mixture is subsequently subjected to a separation process to remove the water. Applicable separation processes include but are not limited to distillation processes, membrane separation processes, or a combination thereof.
In embodiments of this disclosure, the separation process used to form the hydrogen peroxide solution in TBA can be carried out by distillation, including vacuum distillation, that is, a distillation conducted under vacuum. In this distillation process, water is removed overhead with TBA, while hydrogen peroxide remains in the bottom as a TBA solution. The distillation process can be a continuous process. The amount of TBA used in the process, and the parameters of the distillation process such as the distillation temperature and pressure, can be manipulated to achieve the desired concentration of the three components, hydrogen peroxide, water, and TBA in the final mixture. For example, a sufficiently large weight percent excess of TBA compared to the weight percent of water in the feed can be used so that the bottom solution contains almost exclusively hydrogen peroxide and TBA and retains low concentrations of water, such as less than about 1 wt % water.
In embodiments, the distillation process can be a continuous process such as illustrated in
In Step (102), fresh (non-recycled) alcohol (120) shown as TBA in
Step (104) of
In some embodiments, the overall continuous process can include a dilution step, shown as Step (106) of
Step (108) of
In some embodiments, an integration of a TBA source and TBA-H2O2 user can be a continuous process such as illustrated in
In Step (302), isobutane (320) reacts with oxygen (330) to form an organic hydroperoxide solution (340), which is then separated and purified.
In Step (304), the organic hydroperoxide solution (340) from Step (302) reacts with propylene (350) and catalyst (360) to form two main products, propylene oxide (PO) (370) and tert-butyl alcohol (TBA) (380) as a mixture (390).
In Step (306), the two main products PO (370) and TBA (380) are separated and purified. Some portion of the TBA (380) product is sent to the HPPO plant (308, 310, 312).
In Step (308), the TBA (380) is used to remove water from the H2O2 solution in water (140) as described in
In Step (310), the TBA-H2O2 (30) reacts with propylene (350) and catalyst to form PO and water (400).
In Step (312), the main product PO and water (400) are separated and purified PO (370) formed. The TBA water mixture (20) is recycled back to Step (306).
As described in
The disclosed method of forming a hydrogen peroxide solution in a non-aqueous solvent combines a non-aqueous solvent such as an alcohol with an aqueous hydrogen peroxide solution to form a first mixture, followed by removing water from the first mixture to obtain an non-aqueous solvent-based hydrogen peroxide solution sometimes referred to herein as the final or second mixture. Any aqueous hydrogen peroxide solution in any concentration can be used as a starting solution to prepare the non-aqueous hydrogen peroxide solution. For example, the starting H2O2 solutions in water can range from about 3 wt % to about 60 wt % H2O2 in water.
The concentration of the hydrogen peroxide in the final non-aqueous solvent-based hydrogen peroxide solution can range from about 1 wt % to about 70 wt % or even higher. The non-aqueous solvent can be an alcohol as described herein. As the skilled person will appreciate, caution should be used when preparing and handling H2O2 solutions that are more concentration than about 70 wt % H2O2.
In embodiments, the concentration of the hydrogen peroxide in the final non-aqueous solvent-based hydrogen peroxide solution such as an alcohol-hydrogen peroxide solution, can range from about 0.5 wt % to about 70 wt %, from about 1 wt % to about 60 wt %, from about 10 wt % to about 50 wt %, or from about 15 wt % to about 45 wt %. In embodiments, the concentration of the hydrogen peroxide in the final non-aqueous solvent-based hydrogen peroxide solution such as an alcohol-hydrogen peroxide solution, can be about 1 wt %, 2 wt %, 5 wt %, 10 wt %, 20 wt %, 30 wt %, 40 wt %, 50 wt %, 60 wt %, or even 70 wt %, including any ranges between any of these weight percentage numbers. Accordingly, the concentration of the alcohol or other non-aqueous solvent in the final non-aqueous solvent-based hydrogen peroxide solution can be about 99 wt %, 98 wt %, 95 wt %, 90 wt %, 80 wt %, 70 wt %, 60 wt %, 50 wt %, 40 wt %, or 30 wt %.
In the final non-aqueous solvent-based hydrogen peroxide solutions such as an alcohol-hydrogen peroxide solution, some water can be present. In embodiments, the water can be less than or equal to about 5 wt %, 4 wt %, 3 wt %, 2 wt %, or 1 wt % of the total non-aqueous solvent-based hydrogen peroxide solution.
Also in the final non-aqueous solvent-based hydrogen peroxide solution such as an alcohol-hydrogen peroxide solution, a certain concentration of various non-hydrogen peroxide and non-water contaminants can also be present. In embodiments, the final non-aqueous solvent-based hydrogen peroxide solution can contain less than or equal to about 3 wt %, 2.5 wt %, 2 wt %, 1.5 wt %, 1 wt %, or 0.5 wt % or other components.
In embodiments, the non-aqueous solvent selected for the process can be an alcohol which forms an azeotrope with water. In an aspect, the alcohol can have a boiling point lower than that of H2O2 at the same pressure, for example, at reduced pressure. In embodiments, the azeotropic mixture formed from the selected alcohol with H2O also can have a boiling point lower than that of H2O2 at the same pressure. For example, the alcohol can be selected from a primary alcohol, a secondary alcohol, a tertiary alcohol, or a combination thereof, which has a boiling point lower than that of H2O2 at the same pressure.
In some embodiments, the alcohol can be selected from an alcohol that can have a boiling point at least 25° lower than the boiling point of H2O2, measured at standard pressure (1 atmosphere). In some embodiments, the alcohol can have a boiling point at least 30° lower, at least 35° lower, at least 35° lower, at least 40° lower, at least 45° lower, at least 50° lower, at least 55° lower, at least 60° lower, at least 65° lower, at least 70° lower, or at least 75° lower than the boiling point of H2O2, measured at standard pressure (1 atmosphere). When the non-aqueous solvent is not an alcohol, the non-aqueous solvent can have a boiling point lower than the boiling point of H2O2 by the same amounts disclosed here for an alcohol, when measured at 1 atmosphere pressure.
In other embodiments, the alcohol can be selected such that the azeotrope formed from the alcohol and water can have a boiling point at least 30° lower than the boiling point of H2O2, measured at standard pressure (1 atmosphere). In some embodiments, the azeotrope can have a boiling point at least 35° lower, at least 35° lower, at least 40° lower, at least 45° lower, at least 50° lower, at least 55° lower, at least 60° lower, at least 65° lower, at least 70° lower, or at least 75° lower than the boiling point of H2O2, measured at standard pressure (1 atmosphere). When the non-aqueous solvent is not an alcohol, the non-aqueous solvent can be selected such that the azeotrope formed from the solvent and water can have a boiling point lower than the boiling point of H2O2 by the same amounts disclosed here for the alcohol, when measured at 1 atmosphere pressure.
In embodiments, alcohols include, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, iso-butanol, tert-butanol (TBA), neopentyl alcohol, tert-amyl alcohol, allyl alcohol, or any combination thereof.
It can be seen from the observed boiling points of the relevant compounds and the azeotropes that tert-butyl alcohol (TBA) works well in the disclosed process. The literature values for the boiling point of TBA at atmospheric pressure is 82.8° C., and pure water boils at 100° C. A TBA:water mixture having a TBA concentration of 88.3 wt % and a water concentration of 11.7 wt % forms an azeotrope having a boiling point of about 79.9° C. Therefore, both the non-aqueous solvent TBA and its azeotropic mixture with water boil at least 65° lower than the boiling point of H2O2, measured at 1 atmosphere pressure.
Non-aqueous solvents for the H2O2 solutions and processes disclosed herein can be selected for their solvation properties to achieve better solubility of non-polar components in polar H2O2 mixtures. In this aspect, non-aqueous solvents other than alcohols can be used in the processes to prepare H2O2 solutions as described herein. In embodiments, for example, non-aqueous and non-alcoholic solvents which can form low boiling point azeotropic mixtures with water which can be used include, for example: esters such as ethyl acetate or methyl acetate; aromatic compounds such as benzene or toluene; ethers such as diethyl ether or tetrahydrofuran; hydrocarbons such as cyclohexane; or nitriles such as acetonitrile.
The hydrogen peroxide concentrations reported in the mixtures were analyzed using the iodometric titration method with an automatic titrator.
This example illustrates the process to replace the water in a H2O2 and water mixture with tert-butyl alcohol (TBA).
A 90 gram (g) portion of TBA is combined with 10 g of a 50 wt % H2O2 solution in water to form a first mixture. This first mixture is then distilled under vacuum conditions to provide 7.71 g of a second mixture in the bottom of the distillation flask containing 48.69 wt % hydrogen peroxide, 50.37 wt % TBA, and 0.94 wt % water. The 71.31 g sample of condensed distillate contained 2.05 wt % hydrogen peroxide and 4.8 wt % water with the balance being TBA, perhaps with minor amounts of decomposition products. The remaining hydrogen peroxide and water originally in the first mixture was in the non-condensed vapor stream.
The bottom product (second mixture) contained 48.69 wt % hydrogen peroxide, 50.37 wt % TBA, and 0.94 wt % water, therefore, most of the water in the original (first) mixture was removed by this process. The concentration of H2O2 in the bottom product (second mixture) can be adjusted to the desired value by using additional amounts of TBA to remove additional water, or by using less TBA to remove less water.
This process simulation example illustrates the impact of the TBA:H2O ratio in the feed on the H2O removal effectiveness or efficiency. In order to achieve low concentrations, that is less than 1 wt %, of water in the final TBA-hydrogen peroxide mixture (second mixture), the weight ratio of TBA to H2O (TBA:H2O; wt/wt) in the original feed (first mixture) can be about 18:1 or higher.
A typical distillation column used in this example has 10 trays, with the feed tray at 5, a reflux ratio at 1, a total condenser and a pressure at the condenser of 3 psia (pounds per square inch, ambient). The feed rate of a 50 wt % H2O2 in water solution was fixed at 10,000 lb/hr into mixing step 102. The TBA stream in this example contained 1% water. See
Table 1 shows the results of this simulation example, namely, the water concentration in the final H2O2-TBA mixture (wt %) that is formed (second column) using increasing TBA:H2O ratios (lb/lb) in the feed (first column).
This process simulation example illustrates the impact of the bottom flowrate to the final H2O2 concentration. A typical distillation column used in this example has 10 trays, with the feed tray at 5, reflux ratio at 1, a total condenser and pressure at the condenser of 3 psia. The total feed of 100,000 lb/hr consists of 10,000 lb/hr of 50 wt % H2O2 in water and 90,000 lb/hr TBA with 1% water.
This process simulation example illustrates the impact of the column pressure to the bottom temperature. In an embodiment, the bottom temperature can be at about 60° C. or less, because higher temperature can lead to increasing H2O2 decomposition which can form oxygen and increase the safety risk of operating the system. A typical distillation column used in this example has 10 trays, with feed tray at 5, reflux ratio at 1, a total condenser and pressure at the condenser of 3 psia. The total feed of 100,000 lb/hr consists of 10,000 lb/hr of 50 wt % H2O2 in water and 90,000 lb/hr TBA with 1% water. The bottom flow rate is fixed at 10,000 lb/hr.
Any publications that may be referenced throughout this specification are hereby incorporated by reference in pertinent part in order to more fully describe the state of the art to which the disclosed subject matter pertains. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided in this disclosure, the definition or usage provided in this disclosure controls.
For any particular compound disclosed herein, the general structure presented is also intended to encompasses conformational isomers and stereoisomers that can arise from a particular set of substituents, unless indicated otherwise. Thus, the general structure encompasses enantiomers, diastereomers, and other optical isomers whether in enantiomeric or racemic forms, as well as mixtures of stereoisomers, as the context permits. For any particular formula that is presented, any general formula presented also encompasses conformational isomers, regioisomers, and stereoisomers that can arise from a particular set of substituents. Accordingly, Applicant reserves the right to proviso out any particular individual isomer or isomers, if for any reason Applicant chooses to claim less than the full measure of the disclosure, for example, to account for a reference that Applicant is unaware of at the time of the filing of the application.
As used in the specification and the claims, the singular forms “a,” “an,” and “the” include plural referents unless the context indicates otherwise. Thus, for example, “a compound” includes mixtures of two or more such compounds, “the composition” includes mixtures of two or more such compositions, and the like.
Terms such as “configured for”, “adapted for”, “adapted to” and similar language is used herein to reflect that the particular recited structure or procedure is used in the recited mixing and separation steps of the disclosed process. For example, unless otherwise specified, a particular structure “configured for use” means it is “configured for use in chemical facility” for the process disclosed herein, therefore is designed, shaped, arranged, constructed, and/or tailored to effect the relevant disclosed mixing and separation steps, as would have been understood by the skilled person.
“Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.
Unless indicated otherwise, when a range of any type is disclosed or claimed, for example a range of the percentages, it is intended to disclose or claim individually each possible number that such a range could reasonably encompass, including any sub-ranges or combinations of sub-ranges encompassed therein. When describing a range of measurements such as these, each possible number that such a range could reasonably encompass can, for example, refer to values within the range with one significant figure more than is present in the end points of a range, or refer to values within the range with the same number of significant figures as the end point with the most significant figures, as the context indicates or permits. For example, when describing a range of percentages such as from 85% to 95%, it is understood that this disclosure is intended to encompass each of 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, and 95%, as well as any ranges, sub-ranges, and combinations of sub-ranges encompassed therein. Applicant's intent is that these two methods of describing the range are interchangeable. Accordingly, Applicant reserves the right to proviso out or exclude any individual members of any such group, including any sub-ranges or combinations of sub-ranges within the group, if for any reason Applicant chooses to claim less than the full measure of the disclosure, for example, to account for a reference that Applicant is unaware of at the time of the filing of the application.
Values or ranges may be expressed herein as “about”, from “about” one particular value, and/or to “about” another particular value. When such values or ranges are expressed, other embodiments disclosed include the specific value recited, from the one particular value, and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. In aspects, “about” can be used to mean within 10% of the recited value, within 5% of the recited value, within 2% of the recited value, or within 1% of the recited value.
Any headings that are employed herein are not intended to be used to construe the scope of the claims or to limit the scope of the subject matter that is disclosed herein. Any use of the past tense to describe an example otherwise indicated as constructive or prophetic is not intended to reflect that the constructive or prophetic example has actually been carried out.
Those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments disclosed herein without materially departing from the novel teachings and benefits according to this disclosure. Accordingly, such modifications and equivalents are intended to be included within the scope of this disclosure as defined in the following claims. Therefore, it is to be understood that resort can be had to various other aspects, embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the spirit of the present disclosure or the scope of the appended claims.
Applicants reserve the right to proviso out any selection, feature, range, element, or aspect, for example, to limit the scope of any claim to account for a prior disclosure of which Applicants may be unaware.
The following numbered claims of this disclosure are provided, which state various attributes, features, and embodiments of the present disclosure both independently, or in any combination when the context allows. That is, as the context allows, any single numbered aspect or claim and any combination of the following numbered aspects or claims provide various attributes, features, and embodiments of the present disclosure.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 63/208,850, filed on Jun. 9, 2021, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63208850 | Jun 2021 | US |
