Reduced water consumption for hydrocarbon production

Abstract

Systems and methods are provided for conversion of renewable power into hydrocarbons, such as hydrocarbon fuels, via a methanol intermediate. In addition, it is desired to capture and reuse carbon dioxide in order to form these hydrocarbons. When the conversion of carbon dioxide is performed using hydrogen generated by electrolysis (preferably from renewable electricity), the management of process water is beneficial for reducing or minimizing the overall water requirements for the process as well as extending the lifetime of the electrolyzers. Systems and methods are also provided for recovery and purification of process water for recycle to the electrolyzers.

Description

REDUCED WATER CONSUMPTION FOR HYDROCARBON PRODUCTIONFIELD OF THE INVENTION

[0001] Systems and methods are provided for reducing the amount of water needed for synthesis of any hydrocarbon that uses methanol as an intermediate molecule.BACKGROUND OF THE INVENTION

[0002] One of the advantages of conventional hydrocarbon fuels relative to current electrical power technology is that the energy density per weight of hydrocarbon fuels is substantially higher than the energy density weight per weight of conventional batteries. This higher stored energy density per weight is beneficial for some applications. While battery technology may eventually improve to the point where the energy density in batteries approaches the energy density in hydrocarbon fuels, until that occurs, conversion of renewable energy into hydrocarbon fuels provides a bridging technology for allowing renewable energy and carbon oxides from the environment to be converted into valuable compounds while reducing or minimizing consumption of conventional petroleum. Thus, it would be desirable to have methods for converting renewable energy to hydrocarbon fuels, particularly if the hydrocarbon fuels can be formed while reducing, minimizing, or avoiding formation of CO2.

[0003] U.S. Patent 1 1 ,565,982 describes a process for conversion of carbon dioxide and power into fuels and chemicals. Electrolysis is used to form H2, which can then be combined with CO2 and exposed to water gas shift reaction conditions to form synthesis gas. The synthesis gas can then be used to form water and hydrocarbons, which can then be separated into a low molecular weight stream and a higher molecular weight stream which is recovered. The low molecular weight hydrocarbon stream is recycled back to a reforming step.

[0004] International Publication WO / 2016 / 193337 describes a method of treating water coming from a Fischer-Tropsch reaction. In its process, process water is treated to remove wax and an anaerobic bioreactor is used to obtain a bio-treated water stream, presumably for return to the environment.

[0005] U.S. Patent 5,714,662 describes a process for conversion of methanol to olefins.

[0006] U.S. Patent Application Publications 2022 / 0396534; 2022 / 0396741; and 2023 / 0212092 describe methods for converting ethylene-containing feeds to higher hydrocarbons, such as jet boiling range hydrocarbons. Such ethylene-containing feeds can optionally be formed in-situ by conversion of methanol.SUMMARY OF THE INVENTION

[0007] In an aspect, a method for water recovery during a process for conversion of methanol to hydrocarbons where hydrogen is provided by an electrolyzer is provided. The method includes converting a feed containing methanol and H2 in a hydrocarbon conversion process to form at least a conversion effluent and a first process water effluent. The method further includes passing at least a portion of the conversion effluent through a carbonyl absorber and a methanol absorber to form a reduced oxygenate conversion effluent and at least one additional process water effluent. The method further includes separating at least a methanol stream and a water recycle stream from a recovery input flow. The recovery input flow can contain the first process water effluent and the at least one additional process water effluent. The water recycle stream can have a total organic carbon content of 300 micrograms per liter or more, a conductivity of 10 uS / cm or more, or a combination thereof. The method further includes exposing at least a portion of the water recycle stream to at least one of a reverse osmosis stage and an electrodeionization stage to form purified water recycle stream having a total organic carbon content of 200 micrograms per liter or less and a conductivity of 5.0 pS / cm or less. Additionally, the method includes performing electrolysis on at least a portion of the purified water recycle stream to generate H2, the feed containing at least a portion of the H2 generated by the electrolysis.

[0008] In another aspect, a system for conversion of methanol to hydrocarbons using H2 generated by an electrolyzer is provided. The system includes a methanol conversion stage for conversion of methanol to hydrocarbons, the methanol conversion stage having a conversion methanol inlet, a conversion H2 inlet, one or more conversion effluent outlets, and at least one conversion process water outlet. The system further includes a carbonyl adsorber having a carbonyl adsorber product outlet, a carbonyl adsorber process water outlet, and a carbonyl adsorber inlet in fluid communication with at least one conversion effluent outlet. The system further includes a methanol absorber having a methanol absorber product outlet, a methanol absorber process water outlet, and a methanol absorber inlet in fluid communication with the carbonyl adsorber outlet. The system further includes a methanol recovery stage having a recovery inlet, a methanol recovery outlet, and a water recycle outlet, the recovery inlet being in fluid communication with the conversion process water outlet, the carbonyl adsorber process water outlet, and the methanol absorber process water outlet. The system further includes a reverse osmosis stage having a reverse osmosis outlet and a reverse osmosis inlet in fluid communication with the water recycle outlet. The system further includes anelectrodeionization stage having an electrodeionization outlet and an electrodeionization inlet in fluid communication with the reverse osmosis outlet. Additionally, the system includes an electrolyzer having a water inlet, a H2 outlet, and an oxygen outlet, the water inlet being in fluid communication with the reverse osmosis outlet, the H2 outlet being in fluid communication with the conversion H2 inlet.

[0009] In still another aspect, a method for forming hydrocarbons is provided. The method includes performing one or more separation processes on an input water flow to produce a purified water feed having a total organics content of 200 micrograms per liter or less, a conductivity of 5.0 pS / cm or less, or a combination thereof. The input water flow can include a make-up water feed and a recycled water feed, the recycled water feed containing 10 wppm or more of methanol. The method further includes passing at least a portion of the purified water feed into an electrolyzer under electrolysis conditions to form H2 and O2. The method further includes passing a methanol synthesis feed containing at least one of CO and CO2 and at least a portion of the H2 formed by the electrolyzer into a methanol synthesis stage under methanol synthesis conditions to form a methanol-containing product. The method further includes converting at least a portion of the methanol-containing product to form a hydrocarbon product containing C2+ olefins and process water. Additionally, the method includes forming at least a portion of the recycled water feed from at least a portion of the process water.BRIEF DESCRIPTION OF THE FIGURES

[0010] FIG. 1 shows a relationship between the water required for electrolysis relative to the amount of hydrocarbons produced as the amount of CO2 used for synthesis of the hydrocarbons is increased.

[0011] FIG. 2 shows an example of an integrated configuration for using hydrogen generated by electrolysis and carbon oxides to form hydrocarbon products.

[0012] FIG. 3 shows a process flow for separating the products from a methanol synthesis process.

[0013] FIG. 4 shows a process flow for separating the products from a methanol conversion process.

[0014] FIG. 5 shows a process flow for purifying water for use in an electrolyzer.

[0015] FIG. 6 shows another example of an integrated configuration for using hydrogen generated by electrolysis and carbon oxides to form hydrocarbon products.DETAILED DESCRIPTION OF THE EMBODIMENTSOverview

[0016] In various aspects, systems and methods are provided for conversion of renewable power into hydrocarbons, such as hydrocarbon fuels, via a methanol intermediate. In addition, it is desired to capture and reuse carbon dioxide in order to form these hydrocarbons. Although processes such as Fischer-Tropsch and methanol synthesis coupled with methanol to olefins are well-known, both rely upon primarily carbon monoxide as a feedstock. When the conversion of carbon dioxide is performed using hydrogen generated by electrolysis (preferably from renewable electricity), the management of process water is beneficial for reducing or minimizing the overall water requirements for the process and to extend the lifetime of the electrolyzers.

[0017] In particular, use of methanol as a hydrocarbon intermediate has advantages. Methanol can be formed and stored to attenuate the variance in availability that is inherent to many renewable energy sources such solar and wind. After forming a methanol intermediate, the methanol can be used as an input for a methanol conversion process, such as process for conversion of methanol to olefins, a process for conversion of methanol to gasoline and / or diesel boiling range compounds, or another type of methanol conversion process.

[0018] Additionally or alternately, in various aspects, systems and methods are provided for reducing or minimizing water consumption during conversion of hydrogen from electrolysis and carbon oxides into hydrocarbon fuels via a methanol intermediate while also extending operating times for the overall process. The reduced or minimized water consumption is achieved in part by recycling water from the methanol synthesis process for forming the methanol intermediate. This recycle includes sufficient separation stage(s) to allow for increased or maximized run length and / or operating lifetime for the electrolyzer. Water can also be recycled from the subsequent process(es) for forming larger hydrocarbons from methanol (i.e., methanol conversion e.g. to olefins or paraffins, and / or oligomerization processes). The ability to recycle water from both methanol synthesis and larger hydrocarbon synthesis can facilitate conversion of renewable energy into hydrocarbon fuels in environments where renewable energy may be plentiful, but water may be a limited resource. This recycle reduces the strain on the environment by reducing the consumption of fresh water.

[0019] Because of the differences in the respective chemistry and catalysts, the methanol synthesis and methanol conversion processes differ significantly from conventionalpetrochemical and Fischer-Tropsch processes. First, in the reactive steps, the presence of a reformer is not required in the methanol synthesis and methanol-to-olefins processes like it is for a Fischer-Tropsch process to handle low molecular weight impurities. Methanol synthesis and methanol conversion processes produce mostly low molecular weight olefins and have separation processes to recover them for further use. This is in contrast to the high molecular weight paraffins, including wax, that are generated by a Fischer-Tropsch process. Because of these differences, the process steps for removing the impurities and purifying the process water for electrolysis differ substantially for the methanol synthesis and methanol conversion processes relative to the relatively simpler impurity removal steps that are needed for purification of process water from a Fischer-Tropsch process.

[0020] In various aspects, removal and recovery of high concentrations of methanol to enable reuse of the process water from methanol synthesis and a methanol conversion reactor in electrolyzer can be performed using a combination of the following steps: a) carbonyl and methanol absorber for the prevention of red oil formation; b) methanol recovery tower for removal and recycle of methanol back to a methanol conversion process such as methanol to olefins; and c) a reverse osmosis system or an electrodeionization system for the purification of water. This combination of steps allows for creation of a treated process water feed stream to the electrolyzer with a total organics content of 200 micrograms per liter or less and a conductivity of 5.0 pS / cm or less. It is noted that 200 micrograms of organics per liter of water roughly corresponds to having 0.2 weight parts per million (wppm) of organics in a liter of water.

[0021] Conventionally, efforts to convert renewable power to hydrocarbon fuels have focused on methods where renewable power is used to form hydrogen, with at least a portion of the hydrogen being provided directly to a hydrocarbon synthesis reaction, such as a Fischer- Tropsch reaction. U.S. Patent 11,565,982 provides an example of this type of configuration. In U.S. Patent 11,565,982, renewable power is used to generate hydrogen. CO is also acquired, such as by direct air capture. A portion of the hydrogen is then used in a reverse water gas shift process to convert H2 and CO2 into H2O and CO. This is necessary because the subsequent Fischer-Tropsch process requires CO as a process input, and not CO2. A second portion of the hydrogen is then combined with the CO from the reverse water-gas shift process to form a synthesis gas. The Fischer-Tropsch process can then form hydrocarbons from the synthesis gas. Due to the nature of the reverse water-gas shift process, no separation is required to usethe output from the reverse water-gas shift process as part of a synthesis gas for production of Fischer-Tropsch products.

[0022] Although a combination of reverse water-gas shift and Fischer-Tropsch synthesis can be used for conversion of renewable energy to hydrocarbons, a variety of challenges remain. For example, one of the difficulties with conversion of renewable energy and carbon oxides to hydrocarbon fuels is that many types of renewable energy are only intermittently available. For solar energy, the amount of available renewable energy can vary based both on the time of year as well as due to various types of weather-related factors. Wind energy can have even greater variability, depending on the location.

[0023] Conventionally, one possible initial step in conversion of renewable power to other forms of fuel is to use the renewable power for electrolysis of water. Electrolysis of water generates only H2 and O2. Thus, there are no by-products that require disposal. However, relative to other types of fuels, H2 is expensive to store as well as more difficult / expensive to transport. This is a substantial factor in why conventional technologies directly use hydrogen from electrolysis as an input to hydrocarbon synthesis, as the need to store hydrogen is avoided.

[0024] Although direct use of hydrogen from electrolysis as a reagent avoids the need for hydrogen storage, the direct use of the hydrogen from electrolysis also means that the operation and throughput of the Fischer-Tropsch process is tied to the variable availability of the renewable energy source. The wide variation in the amount of renewable energy generated at any given time means that the equipment for the Fischer-Tropsch process (and the associated reverse water-gas shift) has to be sized for peak use, even though most of the time the equipment will be operated well below peak throughput.

[0025] In various aspects, the difficulties with conventional methods for conversion of renewable energy to hydrocarbons can be overcome by using a conversion process that forms a methanol intermediate. Methanol may have limited use as a replacement of some hydrocarbon fuels in the future, but is currently not typically used a for a variety of reasons. Additionally, separation processes are required to recover methanol generated by methanol synthesis, thus adding complexity to a process flow that involves conversion of renewable energy to larger hydrocarbons via a methanol intermediate. However, when compared with the difficulties associated with storage and / or transport of hydrogen, methanol can be readily stored and / or transported at relatively low cost. As a result, once methanol is formed, a subsequent methanol conversion process for forming larger hydrocarbons can be operated independently of the rate of hydrogen production in the electrolyzer. For example, during periods of highavailability for renewable energy, excess methanol can be generated and stored. This stored methanol can then be used during periods of low availability for renewable energy. This allows the methanol conversion process to operate at relatively stable throughput levels independent of the amount of electrolysis being performed.

[0026] In addition to providing systems and methods for conversion of renewable energy to hydrocarbons (such as fuels) via a methanol intermediate, in various aspects, systems and methods are also provided for reducing or minimizing water consumption during conversion of renewable energy to hydrocarbons while also providing increased or maximized run lengths. This is achieved by recovering water from both methanol synthesis and methanol conversion, and then performing separations on the recovered water to provide a high purity water stream for use during electrolysis.

[0027] Methanol synthesis is a method for converting hydrogen and carbon oxides into a liquid compound that can be stored in a relatively convenient manner for use and / or transport. Equations (1) and (2) show the stoichiometry for methanol synthesis when using either CO or CO2 as the carbon source for the methanol synthesis process. Equation (3) is the reverse water gas shift reaction, which can occur in parallel during methanol synthesis.

[0028] (1) 2H2+ CO <=> CH3OH

[0029] (2) 3H2+ CO2<=> CH3OH + H2O

[0030] (3) H2+ CO <=> CO2+ H2O

[0031] As shown in Equations (1) and (2), when methanol synthesis is performed using CO, no water is formed as a product. By contrast, when methanol synthesis is performed using CO2, the stoichiometry requires an extra hydrogen molecule and results in formation of water as an additional product. Although the reverse water gas shift reaction shown in equation (3) often occurs in parallel, the reactions reflect the net addition of water as the carbon dioxide content increases in the feed. Importantly, as the ratio of carbon dioxide to carbon monoxide increases, more hydrogen from electrolysis (and therefore more water for electrolysis) is required.

[0032] When the hydrogen used in methanol synthesis is formed by electrolysis, the water generated during methanol synthesis may be used as a source of water for the electrolysis process if treated properly. However, both the amount of water needed for electrolysis and the amount of water available for recycle can vary depending on the type of carbon oxides used. As the amount of CO2used for methanol synthesis is increased, more water is needed for electrolysis in order to form methanol. However, the amount of water available for recycle also increases. By contrast, for carbon oxide feeds that primarily contain CO, the amount of waterneeded for methanol synthesis is reduced or minimized, and the amount of water available for recycle is also reduced or minimized. Table 1 shows how much the input water to the electrolyzer can be reduced during methanol synthesis by recycle of water generated during methanol synthesis back to the electrolyzer.Table 1 - Recycle of Water to Electrolyzer during Methanol Synthesis

[0033] As shown in Table 1, when the percentage of CO2 in the carbon oxide feed is low, there is little or no reduction of fresh or make-up water to the electrolyzer. This can be understood based on Equation (1), as forming methanol using CO does not result in generation of water as a product. Thus, with a substantially pure CO feed, little or no water is generated during methanol synthesis, and therefore little or no water is available for recycle. As the amount of CO2 in the feed to methanol synthesis increases, however, increasing amounts of water are generated as a product from the reaction, thus providing water that can be recycled to the electrolyzer. It is understood that the water needed for the electrolyzer also increases as the amount of CO2 in the feed increases.

[0034] FIG. 1 shows the combined amount of process water generated during integrated synthesis of jet boiling range compounds from hydrogen and carbon oxides via a methanol intermediate. As shown in FIG. 1, the amount of process water generated varies depending on the amount of CO2 in the carbon oxide feed to the methanol synthesis process. For carbon oxide feeds composed primarily of CO, the amount of process water generated by the integrated (jet boiling range) olefin formation process is roughly 30 wt% of the total products from theprocess. As the amount of CO2 in the carbon oxide feed increases, the amount of water produced increases up to near 50 wt% for an entirely carbon dioxide feed.

[0035] In combination with recycle of excess water from the methanol synthesis process, a substantial overall savings in water can be achieved via recycle of process water back to the electrolyzer. Table 2 show the amount of fresh water savings that can be achieved for integrated synthesis of ethylene when starting with hydrogen formed by electrolysis (via a methanol intermediate). As shown in Table 2, the amount of fresh water reduction that can be achieved increases with increasing CO2 content in the feed for the methanol synthesis process.Table 2 - Recycle of Water to Electrolyzer during Integrated Formation of Ethylene

[0036] In various aspects, the amount of recycled water in the input flow to electrolysis can correspond to 25 wt% or more of the total water, or 30 wt% or more, or 50 wt% or more, such as up to 67 wt%.

[0037] Preferably, the electrolysis can be performed using renewable energy, such as by using electricity generated by solar power, wind, hydrothermal, geothermal, nuclear, and / or hydroelectric power to perform the electrolysis. It is noted that nuclear power is included as a “renewable” power source here, based on the ability of nuclear power to generate electricity while reducing, minimizing, or even avoiding generation of carbon dioxide. More generally, other electricity generating sources can also be used, particularly to help with renewable power intermittency. This can reduce, minimize, or avoid production of CO2 as part of the production of hydrogen for performing methanol synthesis. The carbon oxides can correspond to carbon oxides generated from another process, carbon dioxide captured from the air, or anotherconvenient source of carbon oxides. In some aspects, if the carbon oxides are from a suitable source such as biomass or CO2 captured from air, the resulting methanol and / or larger hydrocarbons formed from the process can be based on carbon that was originally drawn from the atmosphere, thus reducing or minimizing net CO2 emissions.Electrolysis, Water Recycle, and Water Purification

[0038] In various aspects, electrolysis can be used to form hydrogen for use as a synthesis gas component. Any convenient type of electrolyzer can be used, and various types of electrolyzers are commercially available. One example of a suitable electrolyzer is an alkaline electrolyzer. In an alkaline electrolyzer, two electrodes are placed in an alkaline solution of potassium hydroxide or sodium hydroxide. The electrolysis is performed by passing current through the alkaline solution. Various types of nickel-based electrodes are examples of suitable electrodes. Another type of electrode is an electrode based on zirconium and polysulfone. The electrodes are separated by a thin porous foil, which can assist with avoiding electrical shorts while also assisting with maintaining separation of hydrogen and oxygen after formation. It is noted that other types of electrolyzers, such as Proton Exchange Membrane (PEM) electrolyzers and solid oxide electrolyzers can also be used.

[0039] Contaminants, such as organics, amine compounds, oxygen, carbon dioxide, metal cations and anionic halides can all reduce electrolyzer efficiency over time by accumulating in the electrolyzer, either in the electrodes, the membrane or in the electrolyte solution. For example, Proton Exchange Membrane (PEM) electrolyzers contain precious metals at the cathode such as palladium and platinum. The precious metals are easily poisoned by cations (e.g. sodium) and anions (e.g. chlorides). Unless some type of ion-exchange is used to remove anions and cations, contaminant cations (including amines) can substitute for protons in the membrane, thereby reducing the conductivity of the membrane. Both anions and cations will accumulate on the surface of the cathode. Anions, such as chlorides, can also react to release chlorine at the anode, contaminating the hydrogen product. Oxidation of organics at the cathode can also lead to contamination of hydrogen and oxygen. Additionally, silicon and other solid inerts can accumulate on the membrane, which reduces mass transfer.

[0040] As another example, Alkaline Exchange Membrane (AEM) electrolyzers use an anion exchange membrane to separate the cathode and anode and an anionic ionomer to provide conductivity in the catalyst layer. Such electrolyzers often use aqueous solutions of potassium hydroxide or potassium carbonate (< 1 Molar). For this type of electrolyzer, when contaminants are present, excessive iron or nickel (for example) can leach from the upstream steel pipingand vessels, which will accumulate and eventually cause deactivation. Carbon dioxide can also lead to carbonate formation resulting in reduced electrolyte conductivity.

[0041] The electrolyzer can be operated at conventional conditions, according to the type of electrolyzer. The water introduced into the electrolyzer can be of a sufficiently high purity, such as water with a reduced or minimized total organic content, reduced or minimized conductivity, reduced or minimized silica content, and / or reduced or minimized content of sodium and chlorine.

[0042] One of the difficulties with integrated conversion of renewable energy to hydrocarbons is the substantial water requirements for the process. As shown in FIG. 1, the weight of water generated during conversion of renewable energy to hydrocarbons (such as jet fuel) via a methanol intermediate can be roughly comparable to the weight of hydrocarbon that is produced. Because carbon oxides provide no hydrogen, all of the hydrogen in the water generated during the total conversion process starts out as hydrogen generated by electrolysis of water. Thus, being able to process this “waste water” generated during the conversion process and recover it for recycle can substantially reduce the fresh water requirements. Such water that is processed to remove contaminants to allow for recycle back to an electrolyzer can be referred to as “process water”.

[0043] A variety of water feeds can be exposed to a separation process in order to reduce or minimize contaminants. Such feeds can include make-up water for the system as well as process water that has been separated from the methanol synthesis product and / or the methanol conversion product. In this discussion, “make-up” water refers to any additional water added to the system to supplement the recycled “process water”. Depending on the aspect, make-up water can correspond to fresh water, water from another process, or a combination thereof.

[0044] In some aspects, prior to passing through one or more separation stages, a water feed or stream can have a total organic carbon content of 10 milligrams per liter or more, or 300 milligrams per liter or more, or 2500 milligrams per liter or more, such as up to 20,000 milligrams per liter (~2.0 wt%) or possibly still higher. Additionally or alternately, the conductivity of a water feed prior to separation can be 10 pS / cm or more, or 15 pS / cm or more, such as up to 100 pS / cm or possibly still higher. Further additionally or alternately, the sodium and / or chloride content of a water feed prior to separation can be 75 micrograms per liter or more, or 100 micrograms per liter or more, such as up to 500 micrograms per liter or possibly still higher. Still further additionally or alternately, a water feed can have a silica content of750 micrograms per liter or more, or 1000 micrograms per liter or more, such as up to 5000 micrograms per liter or possibly still higher.

[0045] In various aspects, at least a portion of the water feed or stream that is purified for use in recycle to the electrolyzer corresponds to process water from a process involving methanol, such as a methanol synthesis process or a methanol conversion process. In such aspects, the water feed or stream can have a methanol content of 10 milligrams per liter or more, or 300 milligrams per liter or more, or 1500 milligrams per liter or more, or 2500 micrograms per liter or more, or 3000 milligrams per liter or more, such as up to 20,000 milligrams per liter (~2.0 wt%) or possibly still higher

[0046] It is noted that in a conventional reforming process (such steam reforming of methane and / or other reforming processes that require some water) for the conversion of hydrocarbons to a synthesis gas containing a substantia] portion of hydrogen and carbon monoxide, the above water qualities would typically be acceptable. Any small amount of organic present in the process water could be reformed along with the hydrocarbons (such as methane) in the reforming stage. Thus, separations of the process water would not be needed to allow for recycle of water back to a reforming stage for generation of hydrogen.

[0047] In order to reduce or minimize the amount of contaminants and / or conductivity of recycle water prior to use as a feed for electrolysis, a variety of separation processes and / or technologies can be used. Examples of separation processes and / or technologies for water purification include, but are not limited to, use of activated carbon, clays, and / or molecular sieves as sorbent materials or filters; reverse osmosis processes; de-aeration; and distillation processes. It is noted that some loss of water from the processing system may occur during separations due to fugitive emissions and / or as carrier fluid for removal of impurities from the product.

[0048] In some aspects, one or more separations can be performed to reduce the total organic content of the water to 200 micrograms per liter or less, or 50 micrograms per liter or less, such as down to substantially no content of total organics. Total organic content can be measured according to ASTM D7573. Additionally or alternately, one or more separations can be used to reduce the content of sodium and / or chloride to 50 micrograms per liter or less, or 10 micrograms per liter or less, or 5.0 micrograms per liter or less, or 1.0 micrograms per liter or less, such as down to substantially no content of sodium and / or chloride. Sodium and chloride content can be measured according to ASTM E534. Further additionally or alternately, one or more separations can be performed to reduce the content of silica to 500 micrograms per literor les of silica, or 3.0 micrograms per liter or less, such as down to substantially no content of silica. Silica content can be measured according to ASTM D859. Still further additionally or alternately, one or more separations can be performed to reduce the conductivity of the recycle water to 5.0 pS / cm or less of conductivity, or 1.0 pS / cm or less, or 0.25 pS / cm or less, or 0.06 pS / cm or less, such as down to having substantially no conductivity. The conductivity of high purity water can be determined according to ASTM D5391. In some aspects, the water can correspond to Type II reagent water according to ASTM DI 193. Type II reagent water under ASTM DI 193 can have properties that include, but are not limited to, a conductivity of 1.0 pS / cm or less, an electrical resistivity at 25°C of 1.0 MOhm-cm or more, a total organic carbon content of 50 pg / L or less, a sodium content of of 5.0 pg / L or less, a chloride content of 5.0 pg / L or less, and a total silica content of 3.0 pg / L or less.

[0049] FIG. 5 shows an example of a process train for performing separations on make-up water and / or water recovered from methanol synthesis or methanol conversion to prepare the water for use in an electrolyzer. This type of sequence of separations can protect the electrolyzer from upstream process upsets and the corrosion of process components over time, thus increasing the potential run length for the electrolyzer and therefore the run length for the methanol synthesis process. In the configuration shown in FIG. 5, the process water and / or other portions of a water recycle stream for purification are first passed into an antiscaling unit 510 to soften the water by removing bivalent cations that lead to scale formation. The water is then passed into a carbon bed 520, primarily for the removal of chlorine, for example as a chloride. The water is then passed into reverse osmosis stage 530 to remove impurities in general. In some aspects, multiple reverse osmosis units in series and / or a recycle loop can be used so that multiple passes through reverse osmosis units are performed. The water is then passed into mechanical filtration stage 540 to remove any further sediments. The water is then passed into membrane degassing unit 550 to remove any additional dissolved gases such as carbon dioxide. Finally, the water is passed into electrodeionization unit 560 to reduce conductivity (ion removal).

[0050] It is noted that the separation stages shown in FIG. 5 can be arranged in different sequences. For example, in some configurations, carbon bed 520 can be the first unit, followed by antiscaling unit 510, followed by mechanical filtration 540, followed by reverse osmosis unit 530 followed by membrane degassing 550, and then electrodeionization 560. Both a methanol synthesis process and a methanol conversion process may require boiler feed water or steam generation as a utility for operating those or other co-located processes. Typically, thequality requirements for those applications are less stringent that for an electrolyzer. However, it may be advantageous to supply the water for methanol synthesis and / or methanol conversion from a common process water treatment system as used for the electrolyzer, but with the benefit of requiring only a portion of the treatment steps. For example, the water for use as boiler water and / or steam in methanol conversion and / or methanol synthesis may be taken as a side stream from the purification process prior to electrodionization, or prior to electrodeionization and reverse osmosis. As a further improvement, the returning boiler feed water or steam may also be treated be the common process water treatment system.

[0051] It is noted that a conventional water treatment method, such as the method described in International Patent Application Publication WO / 2016 / 193337, is not sufficient to achieve the water quality described for a Type II reagent water in ASTM DI 193. InWO / 2016 / 193337, the wastewater treatment is described as including liquid-liquid separation of hydrocarbons followed by distillation or steam stripping to reduce the hydrocarbon content in the Fischer-Tropsch wastewater from a chemical oxygen demand of 15000-20000 mg / L down to a chemical oxygen demand of less than 2000 mg / L (with additional wax removal). When followed by biological treatment (aerobic or anaerobic), that can be further reduced to a 1000-2000 mg / L and with anaerobic digestion, less than 40 mg / L. This is still substantially above a total organic content of 200 pg / L or less (0.2 mg / L).Methanol Synthesis

[0052] The hydrogen produced by the electrolyzer(s) can be used for methanol synthesis. Any convenient type of methanol synthesis reactor can be used that operates based on conversion of hydrogen with carbon monoxide or carbon dioxide (carbon oxides) to form methanol. During methanol synthesis, one parameter that can be used to characterize the reaction conditions is the module (M), which is based on the relative mole fractions of hydrogen, carbon dioxide, and carbon monoxide in the input flows. The module can be defined according to Equation (3).(3) M = (mol% H2- mol% CO2) / (mol% CO2+ mol% CO)

[0053] Generally, a methanol synthesis reaction can be operated at a module value between 1.0 and 3.0. The combination of hydrogen from the electrolyzer and carbon oxides can be referred to as the methanol synthesis feed. Although this is referred to as a methanol synthesis feed, it is understood that the hydrogen and the carbon oxides can potentially be introduced separately into the methanol synthesis environment. In some aspects, hydrogen (H2) can correspond to 25 vol% or more of the methanol synthesis feed, or 35 vol% or more, or 50 vol%or more, such as up to 75 vol%. In some aspects, carbon dioxide can correspond to 5.0 vol% of the methanol synthesis feed or more, or 10 vol% or more, or 15 vol% or more, such as up to 25 vol%.

[0054] An example of a suitable methanol synthesis reactor is a fixed-bed reactor. In some aspects, a methanol synthesis reactor can operate at a temperature of 200°C to 300°C and pressure from 200 psia (~1.4 MPa-a) to 2000 psia (-14 MPa-a), or 1000 psia (-7.0 MPa-a) to 2000 psia (-14 MPa-a). Optionally, a compression stage can be used to increase the pressure of the hydrogen from the electrolyzer and / or to increase the pressure of the carbon oxides prior to passing the feed streams into the methanol synthesis reactor. A methanol synthesis stage can include one or more reactors. Because methanol synthesis is an equilibrium process, conversion is typically relatively low, so that recycle of unreacted synthesis gas components for use as part of the input flows to methanol synthesis is beneficial. For example, the molar ratio of recycled synthesis gas components to fresh synthesis gas components can be greater than 1.0 : 1, such as up to 7.0 : 1 or possibly still higher. In some aspects, reactors can be arranged in series (with separation of methanol between reactors) to increase conversion of methanol prior to recycling unreacted synthesis gas components back to an earlier point.

[0055] Methanol synthesis is typically performed in the presence of a methanol synthesis catalyst. A variety of examples of methanol synthesis catalysts are known. One commonly used type of methanol synthesis catalyst is a catalyst containing Cu and ZnO, with a molar ratio of Cu to Zn of roughly 2.0 to 3.0. Typically alumina is also incorporated into such a catalyst as a structural promoter. It is noted that this type of catalyst also provides water gas shift activity, which can assist with handling carbon oxide feeds that contain both CO and CO2.Other catalysts such those based upon chromia (chromium oxides) are also able to accomplish methanol synthesis. In addition, various promoters such as transition metals may also be used to improve longer chain alcohol synthesis.

[0056] The initial product stream from a methanol synthesis process can be referred to as “crude methanol”. Such crude methanol also contains water. The crude methanol, containing reaction by-products, impurities and water, is condensed from the synthesis loop and distilled. Table 3 shows an example of representative values for the types of impurities / reaction byproducts present in the crude methanol (in addition to water) when the Module value is about 2 (C:O:H molar ratio is about 1: 1.5:5).Table 3 - Examples of Impurity Levels in Crude Methanol

[0057] FIG. 3 shows an example of process flow / separation scheme for recovering methanol and water from crude methanol. Typically, three columns are used to produce Grade A or AA methanol.

[0058] In the example separation scheme shown in FIG. 3, the first column corresponds to a methanol synthesis stabilizer column 310 which receives a crude methanol stream 301. The stabilizer column 310 removes dissolved gases as a gas phase stream 312. The dissolved gases predominantly correspond to CO2 and some dimethyl ether. This produces a stabilized methanol output flow 315. The presence of both water and CO2 at elevated temperatures results in a corrosive mixture within the stabilizer column 310. The corrosion rate is highest in the middle of this stabilizer, where both water and CO2 are present. The overhead of the column contains very little water, and the bottoms contains no CO2, resulting in lower corrosion rates. Corrosion in the middle of the column is generally controlled by using stainless steel construction and / or by the injection of a basic material 308 to neutralize any acids (typically organic). Although amines could be used as a basic material 308, it can simplify subsequent purification of the recycled water if an alkali hydroxide or alkali carbonate (such as sodium hydroxide, sodium carbonate, or sodium bicarbonate) is used as basic material 308.

[0059] After removal of dissolved gases, the remaining impurities in stabilized methanol output flow 315 are water and other oxygenated species, and a trace quantity of hydrocarbons (typically C4 - C10 linear paraffins resulting from very slow Fischer-Tropsch type side reactions in the methanol synthesis reactors). In the example configuration shown in FIG. 3, two columns are employed for further purification of the methanol. The columns correspond to a lower- pressure distillation column 320 and a higher-pressure distillation column 330. It is noted that operating lower-pressure column 320 and higher-pressure column 330 at different pressuresallows cascading of the condenser of the high-pressure column 330 with the reboiler of the lower-pressure column 320. In the configuration shown in FIG. 3, the lower pressuredistillation column 320 generates an overhead gas stream 321 of additional CO2 and impurities, an intermediate methanol product stream 325, and a bottoms product 329. The bottoms product 329 is then passed into the higher-pressure distillation column 330. The higher- pressure distillation column 330 generates an overhead product of methanol 333, a bottoms wastewater product 338 which also contains some methanol, and optionally a side product 336 that can be referred to as a “fusel oil”. The overhead methanol 333 can be combined with intermediate methanol product 325 to form a combined methanol product 335. The fusel oil side product 336 is predominantly methanol and some water, and also contains the heavier oxygenated and hydrocarbon impurities. Conventionally, such a fusel oil stream is typically burned in a boiler in the methanol plant. However, in some aspects, additional methanol product and water for recycle can be recovered from this type of fusel oil side product.

[0060] In the configuration shown in FIG. 3, any caustic or heavy amine introduced in the stabilizer column 310 would be removed as part of the wastewater product 338 in higher- pressure distillation column 330. The methanol product 333, withdrawn as an overhead product, may be treated with an adsorption bed as a polishing step (not shown) to remove light boiling impurities such as trimethyl amines. Such amines can be reduced or minimized by using, for example, caustic or caustic soda as a base 308 in stabilizer column 310.

[0061] The composition of the wastewater product will differ depending on whether an optional fusel oil product is formed or not. Table 4 shows an example of wastewater composition with and without a separate fusel oil stream when the Module value is about 2 (C:O:H molar ratio is about 1:1.5:5).Table 4 - Process Waste water Composition without a Fusel Oil stream

[0062] By forming a fusel oil sidestream, the size of the downstream water treatment equipment can be reduced because the concentration of oxygenates in the process water frommethanol synthesis is reduced. The fusel oil side stream can be sent to the methanol recovery column in the MTO process wastewater system. Table 5 shows two examples of a fusel oil composition and their withdrawal percentage (methanol lost as a percentage of purified methanol recovered when the Module value is about 2 (C:O:H molar ratio is about 1 :1.5:5). The withdrawal percentage is the methanol rate in the fusel oil stream divided by the total methanol recovered overhead in the purified stream (not in the process water). The fusel oil stream is typically withdrawn in the bottom half of the trays and preferably in the bottom third. The exact composition can also will vary depending upon the type of methanol synthesis catalyst.Table 5 - Fusel Oil Composition

[0063] Conventionally, the downside of withdrawing a fusel oil stream is that the total yield of purified methanol from methanol synthesis is reduced by increasing the rate of fusel oil withdrawal to reduce the level of impurities. Typically, the fusel oil stream would be recycled back to a conventional reforming (steam, dry, etc.). But in a methanol process that uses electrolytic hydrogen, the reforming step may not be present or would require a costly addition. Instead, it is preferred to recover the methanol contained in the fusel oil in the separation section of a downstream methanol conversion process because the product impurities of that process are similar and therefore handled in a similar manner.Methanol Conversion Process

[0064] After forming methanol, a variety of conversion strategies are available for converting methanol. One option is to convert the methanol to dimethyl ether, which is a stable intermediate that can be used as an input for formation of olefins. Another option is to convert the methanol to hydrocarbons, such as olefins, using one or more reaction stages. In some aspects, smaller olefins such as ethylene, propylene, or butenes can be formed. If larger olefinsare desired, such as jet boiling range hydrocarbons, one or more additional reaction stages can be used to oligomerize the smaller olefins to form larger olefins.

[0065] As an example of a multi-stage process for performing a methanol to hydrocarbons conversion process, in a first stage, the methanol feed from methanol synthesis can be exposed to conditions for formation smaller olefins. In some aspects, the conditions can favor formation of ethylene. In another aspect, the conditions can favor the formation of propylene. In other aspects, the conditions can be selected to form a mixture of olefins that can include one or more types of Cr - Ce olefins.

[0066] Conversion of methanol to small olefins can be performed in various ways. One option is to use the methanol as a feed for steam cracking. Steam cracking is a conventional process for converting hydrocarbon-like feeds into olefins. Another option is to expose the methanol feed to a catalyst having a zeolitic framework structure under suitable conditions, such as a temperature of 250°C to 600°C, or 250°C to 500°C. The reaction pressure can vary depending on the reactor configuration. Typically, the partial pressure of methanol present in the reaction environment can range from roughly 5.0 kPa-a to 1000 kPa-a, or 100 kPa-a to 750 kPa-a, or 200 kPa-a to 500 kPa-a.

[0067] In this discussion, a zeolite is defined to refer to a crystalline material having a porous framework structure built from tetrahedra atoms connected by bridging oxygen atoms. Examples of known zeolitic frameworks are given in the “Atlas of Zeolite Frameworks” published on behalf of the Structure Commission of the International Zeolite Association”, 6threvised edition, Ch. Baerlocher, L.B. McCusker, D.H. Olson, eds., Elsevier, New York (2007) and the corresponding web site, htt.p: / / \vww.iza structure.org / databases / . Under this definition, a zeolite can refer to aluminosilicates having a zeolitic framework structure as well as crystalline structures containing oxides of heteroatoms different from silicon and aluminum. Such heteroatoms can include any heteroatom generally known to be suitable for inclusion in a zeolitic framework, such as gallium, boron, germanium, phosphorus, zinc, and / or other transition metals that can substitute for silicon and / or aluminum in a zeolite framework. It is noted that under this definition, a zeolitic framework structure can include materials such as silicoaluminophosphate (SAPO) materials or aluminophosphate (A1PO) materials.

[0068] Generally, the zeolitic framework structure employed in the catalyst can have a silica to alumina molar ratio of at least 40, e.g., from about 40 to about 200. Additionally or alternately, the zeolite can comprise at least one medium pore aluminosilicate zeolite having aConstraint Index of 1-12 (as defined in U.S. Pat. No. 4,016,218). Suitable zeolites can include, but are not necessarily limited to, ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, and the like, as well as combinations thereof. ZSM-5 is described in detail in U.S. Pat. No. 3,702,886 and RE 29,948. ZSM-11 is described in detail in U.S. Pat. No. 3,709,979. ZSM-12 is described in U.S. Pat. No. 3,832,449. ZSM-22 is described in U.S. Pat. No. 4,556,477. ZSM-23 is described in U.S. Pat. No. 4,076,842. ZSM-35 is described in U.S. Pat. No. 4,016,245. ZSM-48 is more particularly described in U.S. Pat. No. 4,234,231. It is noted that materials such as silicoaluminophosphates (SAPOs) or aluminophosphates (AlPOs) can also have zeolitic framework structures, and therefore various types of SAPOs and / or AlPOs can also potentially be suitable for use in the initial conversion of methanol to smaller olefins. For example, SAPOs such as SAPO-18 and S APO-34 are useful for methanol to conversion to olefins. Optionally, the catalyst can further include one or more metal oxides (such as silica, alumina, titania, zirconia) as binders and / or as basic oxides to further facilitate the conversion reactions. Optionally, the activity of the catalyst can be further modified in one or more ways, such as by steaming, by incorporation of phosphorus into the catalyst, or by another convenient method.

[0069] The stream generated from the first methanol conversion stage can then be exposed to one or more additional stages of oligomerization conditions to form larger hydrocarbons. For example, if the first methanol conversion stage produces an olefin product that primarily corresponds to ethylene, two additional oligomerization stages can be used to first oligomerize the ethylene to C3 - Ce olefins, and then oligomerize the C3 - Ce olefins to form an oligomerized product including jet boiling range hydrocarbons. In other aspects where the initial conversion stage forms a mixture of one or more C2 - Ce olefins, a single oligomerization stage may be sufficient to form higher boiling hydrocarbons. It is understood that a wide variety of methanol conversion conditions can be used, depending on the desired number of stages and the target types of products for production in the methanol conversion process.

[0070] As an example, in an aspect where the initial methanol conversion stage produces an olefinic output that corresponds to 50 wt% or more of ethylene, two additional oligomerization stages can be used to form jet boiling range products. In such an example, the two oligomerizations can have similar chemical reactions, but typically are not identical steps. In some aspects, the chemistries of the two subsequent oligomerization steps may be accomplished by very different processes. For example, the first oligomerization may be achieved with high efficiency and efficacy in the liquid phase using a homogenous catalyst. Incontrast, the second oligomerization of higher molecular weight olefins, such as propylene and butenes, may be more efficiently and effectively carried out with a heterogeneous catalyst under conditions where some or all of the components are supercritical. By separately oligomerizing the ethylene to a higher molecular weight olefin, the resultant olefins may be included as a portion of the feedstock in the second oligomerization, thereby increasing the overall yield of the higher molecular weight olefins (e.g., C10+ olefins). In such an aspect, the overall process may benefit from separately using (a) a first oligomerization catalyst specific to high yields of ethylene oligomerization and (b) second oligomerization catalysts that have high yields of distillate-range olefins from olefin feedstock that has minimal amounts of ethylene. Because the two oligomerizations are completed as separate processes (although said processes may be performed in different portions of the same vessel), the overall methods and systems may have higher yields of distillate-range olefins that may then be used to produce the isoparaffinic stream and additional fuel products (e.g., distillates, jet fuel, kerosene, and the like).

[0071] The first oligomerization may occur in a first oligomerization unit, which may comprise one or more serial reactors, typically fixed bed adiabatic reactor(s) housing (or otherwise containing) the heterogenous oligomerization catalyst or a continuous stir tank reactor (CSTR) or pump-around piping system for housing a homogenous oligomierzation catalyst.

[0072] Examples of catalysts used in the first oligomerization may include, but are not limited to, (a) homogenous catalysts including (al) homogenous catalysts containing organic aluminum, nickel, titanium, and / or zirconium or (a2) Ziegler types where (al) or (a2) may optionally include a ligand for activating the metal and may optionally include a solvent such as a hydrocarbon or ionic liquid cyclohexane; (b) heterogeneous catalysts such as (bl) solid phosphoric acid, (b2) microporous materials such as zeolites, for example, ZSM-5 catalyst, ZSM-57 catalyst, ZSM-22 catalyst, ZSM-48 catalyst, ZSM-12 catalyst, or (b3) silicoaluminophosphate (SAPO) molecular sieves; (c) the like; and (d) any mixture thereof.

[0073] Contact between the ethylene stream and the first oligomerization catalyst may be under conditions suitable for oligomerizing ethylene. For example, the temperature may be roughly 25 °C to 300°C (or 50°C to 200°C). For example, the pressure may be roughly 100 psia (-0.7 MPa-a) to 2000 psia (-14 MPa-a), or 200 psia (-1.4 MPa-a) to 1200 psia (-8.3 MPa-a), or 250 psia (-1.7 MPa-a) to 1000 psia (-7.0 MPa-a).

[0074] The first oligomerization stage can generate an olefinic output with a reduced or minimized content of ethylene, while having an increased content of propylene and / or C4+ olefins. More generally, the olefinic output from the first stage may contain any single C3 to C9 olefin or any mixture thereof in any proportion. The olefinic output from the first oligomerization can then be exposed to second oligomerization conditions in a second oligomerization unit. The second oligomerization unit, for example, may comprise a fixed bed adiabatic reactor housing (or otherwise containing) the oligomerization catalyst or an isothermal tubular reactor housing (or otherwise containing) the oligomerization catalyst.

[0075] Examples of oligomerization catalysts that may be used in the second oligomerization include, but are not limited to, the zeolite families respectively comprising, MWW family (e.g., MCM-22), *BEA family (e.g., zeolite beta ), FAU catalyst, MTW family (e.g., ZSM-12), TON family (e.g., ZSM-22), MTT family (e.g., ZSM-23), *MRE family (e.g., ZSM-48), MFS family (e.g., ZSM-57), SAPO molecular sieves, the like, and any mixture thereof.

[0076] Contacting the olefinic output from the first oligomerization stage with the second oligomerization catalyst may be under conditions suitable for oligomerizing olefins. For example, the temperature may be roughly 150°C to 300°C (or 150°C to 250°C, or 200°C to 300°C). For example, the pressure may be roughly 600 psia ( 4.1 MPa-a) to 2000 psia (-14 MPa-a) or 600 psia (-4.1 MPa-a) to 1200 psia (-8.3 MPa-a), or 1000 psia (-7.0 MPa-a) to 2000 psia (-14 MPa-a).

[0077] The second oligomerization unit or a unit between the second oligomerization unit and a subsequent hydroprocessing unit may remove at least one light olefin (e.g., C3-C9 olefins, or C3 to Ce olefins, or C3 to Cs olefins) stream from the isoolefinic product stream generated by the second oligomerization unit. Said light olefins may be recycled back as a portion of the feed to the second oligomerization unit.

[0078] In some aspects, the isoolefinic product stream generated by the example configuration described above corresponds to an example of the type of product stream that can be generated when forming jet boiling range compounds from hydrogen (generated by electrolysis) and carbon oxides. The composition of the isoolefinic product stream from the second oligomerization unit depends on, among other things, the conditions for the second oligomerization, the composition of the olefin output from the first oligomerization stage, and the catalyst.

[0079] The isoolefinic product stream may contain predominantly Ce+ olefins (or Cs+ olefins, or C9+ olefins). For example, the isoolefinic stream 112 may contain at least 50 wt% (or at least60 wt%, or at least 70 wt%, or at least 80 wt%, or 50 wt% to 99 wt%, or 50 wt% to 80 wt%, or 60 wt% to 90 wt%, or 70 wt% to 90 wt%, or 80 wt% to 99 wt%, or 94 wt% to 99 wt%) Ce+ olefins (e.g., Ce to C20 olefins) with no greater than 20 wt% C5- olefins (or no greater than 10 wt% C5- olefins, or no greater than 5 wt% C5- olefins). In another example, the isoolefinic product stream may contain at least 50 wt% (or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or 50 wt% to 99 wt%, or 50 wt% to 80 wt%, or 60wt% to 90 wt%, or 70 wt% to 90 wt%, or 80 wt% to 99 wt%, or 94 wt% to 99 wt%) Cs+ olefins (e.g., Cs to C20 olefins) with no greater than 20 wt% C7- olefins (or no greater than 10 wt% C7- olefins, or no greater than 5 wt% C7- olefins). In yet another example, the isoolefinic product stream may contain at least 50 wt% (or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or 50 wt% to 99 wt%, or 50 wt% to 80 wt%, or 60 wt% to 90 wt%, or 70 wt% to 90 wt%, or 80 wt% to 99 wt%, or 94 wt% to 99 wt%) C9+ olefins (e.g., C9 to C20 olefins) with no greater than 20 wt% Cs- olefins (or no greater than 10 wt% Cs- olefins, or no greater than 5 wt% Cs- olefins).

[0080] At least 50 wt% (or at least 60 wt%, or at least 70 wt%, or at least 80 wt%, or 50 wt% to 99 wt%, or 50 wt% to 80 wt%, or 60 wt% to 90 wt%, or 70 wt% to 90 wt%, or 80 wt% to 99 wt%, or 94 wt% to 99 wt%) of the olefins in the isoolefinic stream 112 may be isoolefinic.

[0081] For example, 80 wt% or more of the isoolefinic product stream, or 90 wt% or more, or 94 wt% or more, or 97 wt% or more, may be composed of C9 to C20 isoolefins. Further, 2.0 wt% to 25 wt% of the isoolefinic stream 112 may be composed of C9 olefins (e.g., C9 isoolefins), or 2.0 wt% to 15 wt%, or 5.0 wt% to 25 wt%, or 5.0 wt% to 15 wt%, or 2.0 wt% to 10 wt%. Further, 1.0 wt% to 15 wt% of the isoolefinic stream 112 may be composed of C17+ olefins (e.g., C17+ isoolefins), or 2.5 wt% to 15 wt%. In some aspects, 1.0 wt% to 15 wt% of the isoolefinic stream 112 may be composed of C17 and / or Cis olefins (e.g., C17 and / or Cis isoolefins), or 2.5 wt% to 15 wt%, or 1.0 wt% to 10 wt%, or 2.5 wt% to 10 wt%. Further, the isoolefinic stream 112 may contain 5.0 wt% or less of C19+ olefins (e.g., C19+ isoolefins), or 3.0 wt% or less, or 1.0 wt% or less, such as down to having substantially no content of Ci9+ hydrocarbons. Further, the isoolefinic stream 112 may include 5.0 wt% or less of Cs- olefins, or 3.0 wt% or less, or 1.0 wt% or less, or 0.5 wt% or less, such as down to 0.1 wt% or possibly still lower (i.e., substantially no Cs- olefins).

[0082] In another example, the isoolefinic stream 112 can contain 60 wt% to 90 wt% of Ci 1 to Cis olefins (e.g., Cn to Cis isoolefins). Additionally or alternately, the isoolefinic stream 112 may contain 50 wt% to 75 wt% of C12 to C16 olefins (e.g., C12 to Ci6 isoolefins). This isparticularly advantageous for being suitable for further processing (e.g., hydroprocessing) where the resultant product is flexible for use as an aviation or diesel fuel.

[0083] The isoolefinic stream 112 may contain a reduced or minimized amount of aromatics. This can correspond to containing 5.0 wt% or less of aromatics, or 3.0 wt% or less, or 1.0 wt% or less, or 0.5 wt% or less, or 0.1 wt% or less, such as down to having substantially no aromatics content.

[0084] Mild hydroprocessing can generally convert iso-olefins to isoparaffins with a reduced or minimized amount of reduction in the size of the carbon chains in a fraction. In addition to converting iso-olefins to isoparaffins, hydroprocessing of a kerosene fraction can also be used to remove sulfur, remove nitrogen, saturate olefins, saturate aromatics, and / or for other purposes.

[0085] In addition to forming olefins and / or larger hydrocarbons, a methanol conversion unit also generates process wastewater. The process wastewater can be formed as a reaction product, added as a fluidization aid, and / or added via boiler feed water which is added to the process as a pardoning agent in the separations section. Because of all of the water and oxygenate / hydrocarbon interfaces, the process wastewater contains many impurities. The impurities can include alcohols, such as methanol and ethanol; organic acids, such as formic and acetic acid; inorganic cations such as sodium, silicon and aluminum that leach from the methanol conversion catalyst and / or are added to the process to adjust the pH of a stream; copper or zinc that leach from the methanol catalyst; inorganic anions such as phosphate, chloride and carbonate that come from the methanol conversion catalyst and dissolved carbon dioxide; and / or suspended solids, such as catalyst particles and fines. Other trace contaminants such as iron will also leach over time.

[0086] FIG. 4 shows an example of a process flow for product recovery for a methanol conversion process that corresponds to a methanol to olefins conversion process. Optionally, after forming olefins, the olefins can be converted to higher molecular weight compounds, such as by oligomerization.

[0087] In the example shown in FIG. 4, conversion reactor 410 is fed with methanol 405 for reaction and steam 401 for fluidization and dilution. This generates a conversion effluent 415 that is passed into quench tower 420. Cooler boiler feed water 422 is added to quench tower 420 to stabilize the product mixture. This results in formation of cooled effluent 425 and a cooled process water stream 428. This facilitates separation of any condensable hydrocarbons and catalyst fines in the tower bottom decanter 430. Tower bottom decanter430 generates a decanter wastewater stream 438 and a condensable hydrocarbons stream 433. The cooled effluent 425 is passed into a carbonyl absorber 440 along with water 441 and optionally additional methanol 442 to aid partitioning. The carbonyl absorber partitions the oxygenates, such as aldehydes and ketones into second process water stream 448, preferably to less than 300 wppm. The resulting output 445 from the carbonyl absorber 440 is then passed into methanol absorber 450. Methanol absorber 450 uses water 451 to remove additional methanol and oxygenates to less than 1000 wppm TOC. This results in formation of output 455 and third process water stream 458. Output 455 corresponds to a stream with a reduced content of oxygenates. Output 455 is then passed into scrubber 460, along with caustic stream 463. The scrubber 460 removes any acids or acid forming gases (organic and inorganic) as part of spent caustic stream 469. More generally, a scrubber 460 is preferably a caustic scrubber but can correspond to any type of aqueous wash stage that allows the hydrocarbon product to be washed with an aqueous wash that has a pH of 9.0 or higher, such as a pH of up to 12 or possibly still higher. The hydrocarbon product 465 is also separated out from remaining effluent portion 467. In the example shown in FIG. 4, the hydrocarbon product 465 is primarily olefins, which may then go to hydrocarbon separation (not shown) for recovery or further reaction, such as oligomerization. The remaining effluent portion 467 is then passed into methanol recovery separator 470 along with the other process water streams. The combination of input flows into methanol recovery separator 470 can be referred to as a recovery input flow. It is noted that the various flows used to form the recovery input flow can be combined prior to entering methanol recovery separator 470, after entering separator 470, or some can be combined prior to entering separator 470 while others are combined after entering separator 470.

[0088] In methanol recovery separator 470 (such as a distillation stage), methanol 475 is separated from water recycle stream 478. If an optional fusel oil stream is formed during methanol synthesis, such fusel oil can also be added 472 into the methanol recovery separator for additional recovery of methanol and additional contribution to the water recycle stream. The water recycle stream 478, optionally in combination with make-up water, can then be exposed to further purification steps, such as the process flow shown in FIG. 5, to form a purified water recycle stream for use as an input to an electrolyzer. The recovered methanol 475 can be recycled back to the methanol conversion process 410 for additional formation of hydrocarbon products. It is noted that by including carbonyl absorber 440 and methanol absorber 450, the formation of higher molecular weight oligomerized species (red oil) incaustic scrubber 460 is reduced or minimized, so that the hydrocarbon contaminants that enter methanol recovery separator 470 primarily correspond to Cs or smaller hydrocarbons.

[0089] It is noted that FIG. 4 also illustrates various types of fluid communication between process elements and / or stages. Generally, fluid communication can correspond to direct fluid communication or indirect fluid communication. Direct fluid communication means that the output from one process element I stage is passed into another process element I stage without going through an intervening process element or stage. Indirect fluid communication means that an intervening process element I stage is between two other elements and / or stages. For example, in FIG. 4, carbonyl adsorber 440 is shown as being in direct fluid communication with methanol absorber 450. Similarly, methanol absorber 450 is in direct fluid communication with caustic scrubber 460. By contrast, carbonyl adsorber 440 is in indirect fluid communication with caustic scrubber 460 via methanol absorber 450.

[0090] A configuration similar to FIG. 4 can provide a variety of advantages when integrating a methanol conversion process with electrolysis for forming hydrogen from renewable energy. For example, controlling the pH with caustic instead of amines enables the removal of sodium without the potential to create ammonia or NOx in other equipment or poison process or electrolysis catalysts by adsorption. Removal of carbon dioxide prevents the formation of carbonates which can foul downstream equipment such as ion-exchange resins and electrolyzers. Reduction of organic hydrocarbons prevents their oxidation to form carbon oxides in the electrolyzer leading to potential yield loss and carbonate formation, reducing the efficacy of the electrolyzer. Removal of solids reduced the potential for plugging of downstream equipment such as reverse osmosis membranes, ion-exchange resins and electrolyzer membranes.

[0091] Any water recovered from methanol synthesis and / or methanol conversion can be subsequently purified to allow for recycle and use as part of the input water flow for electrolysis. Due to the nature of the respective recovery trains for methanol synthesis and for methanol conversion, a the process water from both methanol synthesis and methanol conversion can contain a variety of contaminants at elevated levels relative to the target water purity for electrolysis.

[0092] It is further noted that the recovery train shown in FIG. 4 requires addition of water at several locations as part of the recovery train. Table 6 shows an example of suitable properties for the make-up water used in the recovery train so that the wastewater product generated from methanol recovery separator 470 will be of sufficient quality to allow for further processing forwater recycle to the electrolyzer. Table 6 also shows an example of the contaminants in the spent caustic stream.Table 6 - Process Water and Spent CausticConfiguration Examples

[0093] FIG. 2 shows an example of an integrated process for using electrolysis to make hydrogen as part of conversion of hydrogen and carbon oxides into larger hydrocarbons via a methanol intermediate. In FIG. 2, the dotted line encircling the figure represents the boundary of the process for identifying feed and / or product streams that enter or exit the process.

[0094] In FIG. 2, fresh and / or make-up water is introduced to the process in stream 201. The fresh and / or make-up water 201 is passed into a purification stage 210 to prepare purified water for use in electrolysis 220. Purification stage 210 can include, for example, one or more of the separations shown in FIG. 5. A purified recycle water stream 285 is also introduced into electrolysis 220. Electrolysis process 220 uses power 222 to convert the water into electrolysis product stream 225 which contains oxygen and hydrogen. Power 222 can be from any convenient source. Preferably, power 222 corresponds to electrical power originating from a renewable source, such as solar, wind, hydroelectric, nuclear, geothermal, or a combination thereof.

[0095] The electrolysis products 225 pass through a separation process 226 to form a hydrogen stream 228 and an oxygen stream 227. The oxygen stream 227 exits from the process flow and can be used for any other convenient purpose. At least a portion of hydrogen stream 228 is sent to a methanol synthesis process 230, along with a carbon oxides input 232. Optionally, a second portion (not shown) of the hydrogen can also be passed directly into the subsequent methanol conversion process 250 (for conversion of impurities such as diolefins, acetylenes and other oxygenates or to stabilize the formation of dimethyl ether). Optionally, athird portion (not shown) of the hydrogen can used also be passed into an olefin conversion process (for the conversion of olefins or iso-olefins to paraffins or isoparaffins), for example as those formed from the oligomerization of olefins formed from the methanol conversion process. Preferably, the carbon oxides can originate from a biological source, a process waste stream (including combustion processes), direct air capture, or a combination thereof. Conventional sources such as reforming of hydrocarbons (natural gas) are also sufficient. The carbon oxides are primarily carbon dioxide and carbon monoxide but other impurities may be present. The carbon oxides would have already undergone treatment to remove impurities, but some additional impurities, which correspond to any component that is not CO or CO2, such as nitrogen, can be present in an amount of 3.0 vol% or less, or 1.0 vol% or less, such as down to having substantially no impurities (0.1 vol% or less). Removal of those impurities during methanol purification is beneficial to prevent their accumulation and subsequent dilution of the internal recycle stream in methanol synthesis (not shown). Internal to the methanol synthesis step 230, the carbon oxides are converted to an effluent 235 containing methanol and water. The effluent 235 is then separated 240 to form methanol stream 245, water stream 247, and a purge stream 243. The methanol synthesis process generally contains a recycle loop (not shown) to increase the overall conversion to methanol as the single pass conversion is thermodynamically limited. It is noted that separation stage 240 can include various separations, such as the separations shown in FIG. 3.

[0096] The methanol stream 245, which typically also contains some water, is fed to a methanol conversion step 250. Methanol conversion step 250 can correspond to any convenient type of process for converting methanol to hydrocarbons, such as methanol to olefins, methanol to jet, methanol to gasoline, or another type of methanol conversion process such conversion of methanol to dimethyl ether. The methanol conversion process 250 produces a mixture of hydrocarbons (or optionally organic oxygenates) and water. The mixture of hydrocarbons and water can be separated 260 to form a hydrocarbon product stream 265 and a recycle water stream 267. A purge stream 263 is also formed. The hydrocarbon product stream 265 can be sent to product recovery (not shown) for further separation, purification, and reaction such as the dimerization or oligomerization with hydrogen (from 228 for example) for the formation of paraffins and isoparaffins. The water recycle stream 267 from separation 260 may be combined with water stream 247 from methanol synthesis process 240. The water recycle stream 267 and water stream 247 from methanol synthesis can be treated in a single water purification stage 270, or alternatively each stream can be treated in its own water purificationstep (not shown). In aspects where separate purification steps are used for recycle stream 267 and water stream 247, it is noted that water stream 247 (from methanol synthesis) will typically contain fewer impurities than recycle stream 267 (from methanol conversion), and therefore the purification for water stream 247 can be less severe. It is noted that separation 260 can include the various types of separations shown in FIG. 4.

[0097] In the configuration shown in FIG. 2, purification stage 270 corresponds to a conventional purification stage, such as a purification stage based on processing the water using aerobic and / or anaerobic bacterial processes. This produces water of sufficient purity for exhausting a water stream 277 to the environment. However, additional purification 280 is needed to purify stream 275 sufficiently to form recycled water stream 285. Optionally, at least a portion of stream 277 can also be sent for additional purification 280. Additional purification 280 can include, for example, the types of separation processes shown in FIG. 5.

[0098] FIG. 6 shows a process flow that includes several variations relative to FIG. 2. In FIG. 6, the separation stage 640 for separating the effluent from methanol synthesis also produces a fusel oil stream 649. As an example, the separations shown in FIG. 3 include an option for forming a fusel oil. The fusel oil stream 649 is passed into separation stage 660 for separation of the hydrocarbon products and water. It is noted that separation 660 can include the various types of separations shown in FIG. 4. Additionally, in the configuration shown in FIG. 6, the water for recycle back to the electrolyzer does not pass through conventional purification stage 670.Only the portion of water for exhaust as a waste water stream 675 is passed into purification stage 670. Instead, all of the separations for forming recycle water stream 685 are performed in purification stage 680, which can include, for example, the types of separation processes shown in FIG. 5.Additional Embodiments

[0099] Embodiment 1. A method for water recovery during a process for conversion of methanol to hydrocarbons where hydrogen is provided by an electrolyzer, the method comprising: converting a feed comprising methanol and H2 in a hydrocarbon conversion process to form at least a conversion effluent and a first process water effluent; passing at least a portion of the conversion effluent through a carbonyl absorber and a methanol absorber to form a reduced oxygenate conversion effluent and at least one additional process water effluent; separating at least a methanol stream and a water recycle stream from a recovery input flow, the recovery input flow comprising the first process water effluent and the at least one additional process water effluent, the water recycle stream having a total organic carboncontent of 300 micrograms per liter or more, a conductivity of 10 S / cm or more, or a combination thereof; exposing at least a portion of the water recycle stream to at least one of a reverse osmosis stage and an electrodeionization stage to form purified water recycle stream having a total organic carbon content of 200 micrograms per liter or less and a conductivity of 5.0 |iS / cm or less; and performing electrolysis on at least a portion of the purified water recycle stream to generate H2, the feed comprising at least a portion of the H2 generated by the electrolysis.

[0100] Embodiment 2. The method of Embodiment 1 , further comprising: exposing the reduced oxygenate conversion effluent to an aqueous wash having a pH of 9.0 or higher to form a washed conversion effluent; separating the washed conversion effluent to form at least a hydrocarbon product portion and a remaining effluent portion, wherein the recovery input flow comprises the first process water effluent, the at least one additional process water effluent, and the remaining effluent portion.

[0101] Embodiment 3. The method of any of the above embodiments, further comprising: cooling the conversion effluent to form a cooled conversion effluent and a cooled water stream containing condensable hydrocarbons, the at least a portion of the conversion effluent comprising at least a portion of the cooled conversion effluent; and separating the cooled water stream to form a stream containing condensable hydrocarbons and a cooled wastewater stream, wherein the recovery input flow comprises the first process water effluent, the at least one additional process water effluent, and the cooled wastewater stream.

[0102] Embodiment 4. The method of any of the above embodiments, wherein the recovery input flow further comprises make-up water.

[0103] Embodiment 5. The method of any of the above embodiments, wherein the methanol to hydrocarbon conversion process comprises a process for conversion of methanol to form olefins, and optionally further comprises a process for oligomerization of at least a portion of the olefins formed by the conversion of methanol.

[0104] Embodiment 7. The method of any of the above embodiments, wherein the at least a portion of the water recycle stream is exposed to a reverse osmosis stage to form a reduced impurity water recycle stream, and wherein at least a portion of the reduced impurity water recycle stream is exposed to the electrodeionization stage, the exposing the at least a portion of the water recycle stream to a reverse osmosis stage optionally comprising exposing the at least a portion of the water recycle stream to a plurality of reverse osmosis filters in series.

[0105] Embodiment 8. The method of Embodiment 7, the method further comprising: passing the water recycle stream through an anti-scaling unit and a dechlorination bed to form a softened, dechlorinated water recycle stream, wherein the at least a portion of the water recycle stream comprises at least a portion of the softened, dechlorinated water recycle stream, the dechlorination bed optionally comprising a carbon bed.

[0106] Embodiment 9. The method of Embodiment 7 or 8, the method further comprising performing at least one of mechanical filtration and degassing on the at least a portion of the reduced impurity water recycle stream prior to exposing the at least a portion of the reduced impurity water recycle stream to the electrodeionization.

[0107] Embodiment 10. The method of any of the above embodiments, the method further comprising: reacting H2 and carbon oxides in a methanol synthesis stage to form a methanol synthesis product and synthesis process water, wherein at least a portion of the H2 reacted in the methanol synthesis stage comprises H2 generated by the electrolyzer, wherein the feed comprises at least a portion of the methanol synthesis product, and wherein the recovery input flow optionally further comprises at least a portion of the synthesis process water.

[0108] Embodiment 11. The method of Embodiment 10, wherein the reacting hydrogen and carbon oxides in the methanol synthesis stage further forms a fusel oil effluent, and wherein the recovery input flow further comprises at least a portion of the fusel oil effluent.

[0109] Embodiment 12. A system for conversion of methanol to hydrocarbons using H2 generated by an electrolyzer, comprising: a methanol conversion stage for conversion of methanol to hydrocarbons, the methanol conversion stage comprising a conversion methanol inlet, a conversion H2 inlet, one or more conversion effluent outlets, and at least one conversion process water outlet; a carbonyl adsorber comprising a carbonyl adsorber product outlet, a carbonyl adsorber process water outlet, and a carbonyl adsorber inlet in fluid communication with at least one conversion effluent outlet; a methanol absorber comprising a methanol absorber product outlet, a methanol absorber process water outlet, and a methanol absorber inlet in fluid communication with the carbonyl adsorber outlet; a methanol recovery stage comprising a recovery inlet, a methanol recovery outlet, and a water recycle outlet, the recovery inlet being in fluid communication with the conversion process water outlet, the carbonyl adsorber process water outlet, and the methanol absorber process water outlet; a reverse osmosis stage comprising a reverse osmosis outlet and a reverse osmosis inlet in fluid communication with the water recycle outlet; an electrodeionization stage comprising anelectrodeionization outlet and an electrodeionization inlet in fluid communication with the reverse osmosis outlet; and an electrolyzer comprising a water inlet, a H2 outlet, and an oxygen outlet, the water inlet being in fluid communication with the reverse osmosis outlet, the H2 outlet being in fluid communication with the conversion H inlet, wherein the reverse osmosis stage optionally comprises a plurality of reverse osmosis filters in series.

[0110] Embodiment 13. The system of Embodiment 12, i) wherein the system further comprises a methanol synthesis stage comprising a synthesis Hr inlet, a synthesis carbon oxides inlet, a synthesis product outlet, and a synthesis process water outlet, the synthesis H inlet being in fluid communication with the H2 outlet, the synthesis product outlet being in fluid communication with the conversion methanol inlet, and the synthesis process water outlet being in fluid communication with the recovery inlet; or ii) wherein the system further comprises a methanol synthesis stage comprising a synthesis H2 inlet, a synthesis carbon oxides inlet, a synthesis product outlet, a fusel oil outlet, and a synthesis process water outlet, the synthesis H2 inlet being in fluid communication with the H2 outlet, the synthesis product outlet being in fluid communication with the conversion methanol inlet, and the fusel oil outlet being in fluid communication with the recovery inlet.

[0111] Embodiment 14. The system of Embodiment 12 or 13, further comprising: a basic wash stage comprising a wash stage outlet and a wash stage inlet in fluid communication with the methanol absorber product outlet; and a product separation stage comprising a product separation inlet, a hydrocarbon product outlet, and a remaining effluent outlet, the product separation inlet being in fluid communication with the wash stage outlet, the remaining effluent outlet being in fluid communication with the recovery inlet.

[0112] Embodiment 15. The system of any of Embodiments 12 to 14, further comprising: a cooling stage for cooling the conversion effluent comprising a cooling stage inlet, a cooling stage water outlet, and a cooled conversion effluent outlet, the carbonyl adsorber inlet being in indirect fluid communication with the at least one conversion effluent outlet via the cooling stage inlet being in fluid communication with the at least one conversion effluent outlet and the cooled conversion effluent outlet being in fluid communication with the carbonyl adsorber inlet, the cooling stage water outlet being in fluid communication with the recycle inlet.

[0113] Embodiment 16. The system of any of Embodiments 12 to 15, wherein the system further comprises: an anti-scaling unit comprising an anti-scaling outlet and an anti-scaling inlet in fluid communication with the water recovery outlet; and a dechlorination bed comprising a dechlorination inlet and a dechlorination outlet, the dechlorination inlet being influid communication with the anti-scaling outlet, the dechlorination outlet being in fluid communication with the reverse osmosis inlet, wherein the water recovery outlet is in indirect fluid communication with the reverse osmosis inlet.Additional Clauses

[0114] Clause 1. A method for forming hydrocarbons, comprising: performing one or more separation processes on an input water flow to produce a purified water feed comprising a total organics content of 200 micrograms per liter or less, a conductivity of 5.0 pS / cm or less, or a combination thereof, the input water flow comprising a make-up water feed and a recycled water feed, the recycled water feed comprising 10 wppm or more of methanol; passing at least a portion of the purified water feed into an electrolyzer under electrolysis conditions to form H and Os; passing a methanol synthesis feed comprising at least one of CO and CO2 and at least a portion of the H2 formed hy the electrolyzer into a methanol synthesis stage under methanol synthesis conditions to form a methanol-containing product; converting at least a portion of the methanol-containing product to form a hydrocarbon product comprising C2+ olefins and process water; and forming at least a portion of the recycled water feed from at least a portion of the process water.

[0115] Clause 2. The method of Clause 1 , wherein the forming at least a portion of the recycled water feed comprises performing at least one separation process on the at least a portion of the process water.

[0116] Clause 3. The method of any of the above clauses, wherein at least one of the recycled water feed and the at least a portion of the process water comprises 300 wppm or more of methanol, or 2500 wppm or more of methanol.

[0117] Clause 4. The method of any of the above clauses, wherein the methanolcontaining product further comprises water, the method further comprising separating at least a portion of the water from the methanol-containing product, and wherein the recycled water feed is formed from at least a portion of the process water and at least a portion of the water separated from the methanol-containing product, the forming at least a portion of the recycled water feed optionally further comprising performing the at least one separation process on the at least a portion of the water separated from the methanol-containing product.

[0118] Clause 5. The method of Clause 4, wherein the method further comprises separating a fusel oil stream from the methanol-containing product, the fusel oil stream comprising water, and wherein the recycled water feed further comprises at least a portion of the fusel oil stream.

[0119] Clause 6. The method of any of the above clauses, wherein performing the one or more separation processes on the input water flow comprises a) performing a reverse osmosis process on the input water flow, b) performing electrodeionization on the input water flow, or c) a combination of a) and b).

[0120] Clause 7. The method of Clause 6, wherein performing the one or more separation processes on the input water flow further comprises de-aeration of the input water flow, distillation of the input water flow, exposing the input water flow to activated carbon, performing an antiscaling process on the input water flow, or a combination thereof.

[0121] Clause 8. The method of any of the above clauses, wherein the methanol synthesis feed comprises 25 vol% or more of H2, or wherein the methanol synthesis feed comprises 5.0 vol% or more of CO2, or wherein the recycled water feed comprises 30 wt% or more of the input water flow, or a combination thereof.

[0122] Clause 9. The method of any of the above clauses, wherein the process water comprises a conductivity of 10 pS / cm or more, or wherein the make-up water feed comprises a conductivity of 10 pS / cm or more, or wherein the recycled water feed comprises comprises a conductivity of 10 pS / cm or more, or a combination thereof.

[0123] Clause 10. The method of any of the above clauses, wherein converting at least a portion of the methanol-containing product comprises steam cracking of the at least a portion of the methanol-containing product to form olefins, converting at least a portion of the methanol-containing product in the presence of a catalyst to form olefins, or a combination thereof, the method optionally further comprising oligomerizing at least a portion of the olefins formed by the converting.

[0124] Clause 11. The method of any of the above clauses, wherein methanol synthesis conditions comprise a conversion of carbon oxides of 20 wt% or more.

[0125] Clause 12. The method of any of the above clauses, wherein the methanolcontaining product further comprises carbon oxides, the method further comprising separating the methanol-containing product to form a carbon oxide recycle stream comprising at least a portion of the carbon oxides from the methanol-containing product, wherein passing at least one of CO and CO2 into the methanol synthesis stage comprises passing at least a portion of the carbon oxide recycle stream into the methanol synthesis stage.

[0126] Clause 13. The method of any of the above clauses, i) wherein the purified water feed comprises 50 micrograms per liter or less of sodium, chloride, or a combination thereof;ii) wherein the purified water feed comprises 500 micrograms per liter or less of silica; or iii) a combination of i) and ii).

[0127] Clause 14. The method of any of the above clauses, A) wherein the at least one of CO and CO2 are captured from at least one of air, an exhaust, a waste by-product stream, or a combination thereof; B) wherein the at least one of CO and CO2 are formed from a biological mass conversion process; or C) a combination of A) and B).

[0128] Clause 15. The method of any of the above clauses, I) wherein the electrolyzer comprises at least one of an alkaline electrolyzer, a polymer electrolyte membrane electrolyzer, and a solid oxide electrolyzer; II) wherein power for the electrolyzer comprises electricity generated from solar energy, hydroelectric energy, geothermal energy, wind energy, tidal energy, nuclear energy, or a combination thereof; or III) a combination of I) and II).

[0129] All numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.

[0130] Although the present invention has been described in terms of specific embodiments, it is not necessarily so limited. Suitable alterations / modifications for operation under specific conditions should be apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations / modifications that fall within the true spirit / scope of the invention.

Claims

WHAT IS CLAIMED IS:

1. A method for water recovery during a process for conversion of methanol to hydrocarbons where hydrogen is provided by an electrolyzer, the method comprising: converting a feed comprising methanol and H2 in a hydrocarbon conversion process to form at least a conversion effluent and a first process water effluent; passing at least a portion of the conversion effluent through a carbonyl absorber and a methanol absorber to form a reduced oxygenate conversion effluent and at least one additional process water effluent; separating at least a methanol stream and a water recycle stream from a recovery input flow, the recovery input flow comprising the first process water effluent and the at least one additional process water effluent, the water recycle stream having a total organic carbon content of 300 micrograms per liter or more, a conductivity of 10 pS / cm or more, or a combination thereof; exposing at least a portion of the water recycle stream to at least one of a reverse osmosis stage and an electrodeionization stage to form purified water recycle stream having a total organic carbon content of 200 micrograms per liter or less and a conductivity of 5.0 S / cm or less; and performing electrolysis on at least a portion of the purified water recycle stream to generate H2, the feed comprising at least a portion of the H2 generated by the electrolysis.

2. The method of claim 1, further comprising: exposing the reduced oxygenate conversion effluent to an aqueous wash having a pH of 9.0 or higher to form a washed conversion effluent; and separating the washed conversion effluent to form at least a hydrocarbon product portion and a remaining effluent portion, wherein the recovery input flow comprises the first process water effluent, the at least one additional process water effluent, and the remaining effluent portion.

3. The method of any of the above claims, further comprising: cooling the conversion effluent to form a cooled conversion effluent and a cooled water stream containing condensable hydrocarbons, the at least a portion of the conversion effluent comprising at least a portion of the cooled conversion effluent; and separating the cooled water stream to form a stream containing condensable hydrocarbons and a cooled wastewater stream, wherein the recovery input flow comprises the first process water effluent, the at least one additional process water effluent, and the cooled wastewater stream.

4. The method of any of the above claims, wherein the recovery input flow further comprises make-up water.

5. The method of any of the above claims, wherein the methanol to hydrocarbon conversion process comprises a process for conversion of methanol to form olefins, and optionally further comprises a process for oligomerization of at least a portion of the olefins formed by the conversion of methanol.

6. The method of any of the above claims, wherein the at least a portion of the water recycle stream is exposed to a reverse osmosis stage to form a reduced impurity water recycle stream, and wherein at least a portion of the reduced impurity water recycle stream is exposed to the electrodeionization stage, the exposing the at least a portion of the water recycle stream to a reverse osmosis stage optionally comprising exposing the at least a portion of the water recycle stream to a plurality of reverse osmosis filters in series.

7. The method of claim 6, the method further comprising: passing the water recycle stream through an anti-scaling unit and a dechlorination bed to form a softened, dechlorinated water recycle stream, wherein the at least a portion of the water recycle stream comprises at least a portion of the softened, dechlorinated water recycle stream, the dechlorination bed optionally comprising a carbon bed.

8. The method of claim 6 or 7, the method further comprising: performing at least one of mechanical filtration and degassing on the at least a portion of the reduced impurity water recycle stream prior to exposing the at least a portion of the reduced impurity water recycle stream to the electrodeionization.

9. The method of any of the above claims, the method further comprising: reacting H2 and carbon oxides in a methanol synthesis stage to form a methanol synthesis product and synthesis process water, wherein at least a portion of the H2 reacted in the methanol synthesis stage comprises H2 generated by the electrolyzer, wherein the feed comprises at least a portion of the methanol synthesis product, and wherein the recovery input flow optionally further comprises at least a portion of the synthesis process water.

10. The method of claim 9, wherein the reacting hydrogen and carbon oxides in the methanol synthesis stage further forms a fusel oil effluent, and wherein the recovery input flow further comprises at least a portion of the fusel oil effluent.

11. A system for conversion of methanol to hydrocarbons using Hi generated by an electrolyzer, comprising: a methanol conversion stage for conversion of methanol to hydrocarbons, the methanol conversion stage comprising a conversion methanol inlet, a conversion H2 inlet, one or more conversion effluent outlets, and at least one conversion process water outlet; a carbonyl adsorber comprising a carbonyl adsorber product outlet, a carbonyl adsorber process water outlet, and a carbonyl adsorber inlet in fluid communication with at least one conversion effluent outlet; a methanol absorber comprising a methanol absorber product outlet, a methanol absorber process water outlet, and a methanol absorber inlet in fluid communication with the carbonyl adsorber outlet; a methanol recovery stage comprising a recovery inlet, a methanol recovery outlet, and a water recycle outlet, the recovery inlet being in fluid communication with the conversion process water outlet, the carbonyl adsorber process water outlet, and the methanol absorber process water outlet; a reverse osmosis stage comprising a reverse osmosis outlet and a reverse osmosis inlet in fluid communication with the water recycle outlet; an electrodeionization stage comprising an electrodeionization outlet and an electrodeionization inlet in fluid communication with the reverse osmosis outlet; and an electrolyzer comprising a water inlet, a H2 outlet, and an oxygen outlet, the water inlet being in fluid communication with the reverse osmosis outlet, the H2 outlet being in fluid communication with the conversion H2 inlet, wherein the reverse osmosis stage optionally comprises a plurality of reverse osmosis filters in series.

12. The system of claim 11, i) wherein the system further comprises a methanol synthesis stage comprising a synthesis H2 inlet, a synthesis carbon oxides inlet, a synthesis product outlet, and a synthesis process water outlet, the synthesis H2 inlet being in fluid communication with the H2 outlet, the synthesis product outlet being in fluid communication with the conversion methanol inlet, and the synthesis process water outlet being in fluid communication with the recovery inlet; or ii) wherein the system further comprises a methanol synthesis stage comprising a synthesis Hi inlet, a synthesis carbon oxides inlet, a synthesis product outlet, a fusel oil outlet, and a synthesis process water outlet, the synthesis H2 inlet being in fluid communication with the H2 outlet, the synthesis product outlet being in fluid communication with the conversion methanol inlet, and the fusel oil outlet being in fluid communication with the recovery inlet.

13. The system of claim 11 or 12, further comprising: a basic wash stage comprising a wash stage outlet and a wash stage inlet in fluid communication with the methanol absorber product outlet; and a product separation stage comprising a product separation inlet, a hydrocarbon product outlet, and a remaining effluent outlet, the product separation inlet being in fluid communication with the wash stage outlet, the remaining effluent outlet being in fluid communication with the recovery inlet.

14. The system of any of claims 11 to 13, further comprising: a cooling stage for cooling the conversion effluent comprising a cooling stage inlet, a cooling stage water outlet, and a cooled conversion effluent outlet, the carbonyl adsorber inlet being in indirect fluid communication with the at least one conversion effluent outlet via the cooling stage inlet being in fluid communication with the at least one conversion effluent outlet and the cooled conversion effluent outlet being in fluid communication with the carbonyl adsorber inlet, the cooling stage water outlet being in fluid communication with the recycle inlet.

15. The system of any of claims 11 to 14, wherein the system further comprises: an anti-scaling unit comprising an anti-scaling outlet and an anti-scaling inlet in fluid communication with the water recovery outlet; and a dechlorination bed comprising a dechlorination inlet and a dechlorination outlet, the dechlorination inlet being in fluid communication with the anti-scaling outlet, the dechlorination outlet being in fluid communication with the reverse osmosis inlet, wherein the water recovery outlet is in indirect fluid communication with the reverse osmosis inlet.

16. A method for forming hydrocarbons, comprising: performing one or more separation processes on an input water flow to produce a purified water feed comprising a total organics content of 200 micrograms per liter or less, a conductivity of 5.0 pS / cm or less, or a combination thereof, the input water flow comprising a make-up water feed and a recycled water feed, the recycled water feed comprising 10 wppm or more of methanol; passing at least a portion of the purified water feed into an electrolyzer under electrolysis conditions to form H2 and O2; passing a methanol synthesis feed comprising at least one of CO and CO2 and at least a portion of the H2 formed by the electrolyzer into a methanol synthesis stage under methanol synthesis conditions to form a methanol-containing product; converting at least a portion of the methanol-containing product to form a hydrocarbon product comprising C2+ olefins and process water; and forming at least a portion of the recycled water feed from at least a portion of the process water.

17. The method of claim 16, wherein the forming at least a portion of the recycled water feed comprises performing at least one separation process on the at least a portion of the process water.

18. The method of claim 16 or 17, wherein at least one of the recycled water feed and the at least a portion of the process water comprises 300 wppm or more of methanol, or 2500 wppm or more of methanol.

19. The method of any of claims 16 to 18, wherein the methanol-containing product further comprises water, the method further comprising separating at least a portion of the water from the methanol-containing product, and wherein the recycled water feed is formed from at least a portion of the process water and at least a portion of the water separated from the methanol-containing product, the forming at least a portion of the recycled water feed optionally further comprising performing the at least one separation process on the at least a portion of the water separated from the methanol-containing product.

20. The method of claim 19, wherein the method further comprises separating a fusel oil stream from the methanol-containing product, the fusel oil stream comprising water, and wherein the recycled water feed further comprises at least a portion of the fusel oil stream.

21. The method of any of claims 16 to 20, wherein performing the one or more separation processes on the input water flow comprises a) performing a reverse osmosis process on the input water flow, b) performing electrodeionization on the input water flow, or c) a combination of a) and b).

22. The method of claim 21 , wherein performing the one or more separation processes on the input water flow further comprises de-aeration of the input water flow, distillation of the input water flow, exposing the input water flow to activated carbon, performing an antiscaling process on the input water flow, or a combination thereof.

23. The method of any of claims 16 to 22, wherein the methanol synthesis feed comprises 25 vol% or more of H2, or wherein the methanol synthesis feed comprises 5.0 vol% or more of CO2, or wherein the recycled water feed comprises 30 wt% or more of the input water flow, or a combination thereof.

24. The method of any of claims 16 to 23, wherein the process water comprises a conductivity of 10 pS / cm or more, or wherein the make-up water feed comprises a conductivity of 10 pS / cm or more, or wherein the recycled water feed comprises comprises a conductivity of 10 S / cm or more, or a combination thereof.

25. The method of any of claims 16 to 24, wherein converting at least a portion of the methanol-containing product comprises steam cracking of the at least a portion of the methanol-containing product to form olefins, converting at least a portion of the methanol-containing product in the presence of a catalyst to form olefins, or a combination thereof, the method optionally further comprising oligomerizing at least a portion of the olefins formed by the converting.

26. The method of any of claims 16 to 25, wherein methanol synthesis conditions comprise a conversion of carbon oxides of 20 wt% or more.

27. The method of any of claims 16 to 26, wherein the methanol-containing product further comprises carbon oxides, the method further comprising separating the methanol-containing product to form a carbon oxide recycle stream comprising at least a portion of the carbon oxides from the methanol-containing product, wherein passing at least one of CO and CO2 into the methanol synthesis stage comprises passing at least a portion of the carbon oxide recycle stream into the methanol synthesis stage.

28. The method of any of claims 16 to 27, i) wherein the purified water feed comprises 50 micrograms per liter or less of sodium, chloride, or a combination thereof; ii) wherein the purified water feed comprises 500 micrograms per liter or less of silica; or iii) a combination of i) and ii).

29. The method of any of claims 16 to 28, A) wherein the at least one of CO and CO2 are captured from at least one of air, an exhaust, a waste by-product stream, or a combination thereof; B) wherein the at least one of CO and CO2 are formed from a biological mass conversion process; or C) a combination of A) and B).

30. The method of any of claims 16 to 29, I) wherein the electrolyzer comprises at least one of an alkaline electrolyzer, a polymer electrolyte membrane electrolyzer, and a solid oxide electrolyzer; II) wherein power for the electrolyzer comprises electricity generated from solar energy, hydroelectric energy, geothermal energy, wind energy, tidal energy, nuclear energy, or a combination thereof; or III) a combination of I) and II).

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