Patent Description:
The present invention generally relates to systems and methods for liquid mixture separation. More specifically, the present invention relates to membrane based systems and methods for liquid mixture separation that includes a start-up procedure to quickly attain steady state.

Separation of liquid mixtures is an important process in the chemical industry for purifying products and/or recovering unreacted materials. Conventionally, distillation has been the most widely used technique for separating liquid components. However, several drawbacks, including high energy demand, large steam consumption, and low separation efficiency per pass, limit the economic viability of distillation in certain situations.

Separation of mixtures of water and organic compounds such as diols, alcohols, and polyols generally requires a large amount of energy. Because of formation of azeotropes in mixtures of organic compounds and water, the high heat capacity of water, and/or close boiling point range between water and the organic compounds, multi-stage distillation that involves a series of distillation columns with high reflux rate is often employed. Therefore, separation of such water-organic compound mixtures generally requires high capital expenditure and high operational costs. Membrane based techniques, including reverse osmosis, nanofiltration, ultrafiltration and pervaporation, have been explored for liquid mixture separation applications, but the implementation of these technologies on commercial scales is still low due to factors including low separation factor, low fluxes, lack of consistent performance, limited lifetime of membranes and loss of product to lower permeate purities. The flux and selectivity of the best membranes available are limited. Therefore, a large membrane area and/or operation in combination with another separation technique are required to separate compounds of liquid mixtures, which result in limited economic feasibility for membrane based processes. Pervaporation processes are known from <CIT>, <CIT>, and the publication: <NPL>.

Overall, while systems and methods for separating water and organic compounds exist, the need for improvements in this field persists in light of at least the aforementioned drawbacks for the conventional methods.

A solution to at least some of the above-mentioned problems associated with the conventional methods for separating water and organic compounds has been discovered. The solution resides in a method of separating components of a liquid mixture that includes a startup step for fast attainment of steady state and a membrane separation step under optimal conditions. The start-up procedure is capable of shortening the time required to attain steady state compared to the conventional membrane based methods. Furthermore, the operating conditions for membrane separation can be optimized to obtain increased membrane lifetime, multi-fold increase in flux per unit area of the membrane, and increased permeate purity, compared to conventional methods. Moreover, the start-up and/or operating conditions of membrane separation of the disclosed method can be determined and adjusted using one or more algorithms including a machine learning algorithm, an artificial intelligence algorithm, and/or neural network modeling, resulting in quick and accurate adjustment for the conditions and/or parameters for the method. Therefore, the method of the present invention provides a technical solution to at least some of the problems associated with the currently available methods for separating water and organic liquid.

Embodiments of the invention include a method of separating components of a liquid mixture. The method comprises circulating the liquid mixture through one or more membranes of a membrane module. The method comprises increasing circulating flow rate through the membrane module at a flow rate ramp of <NUM> to <NUM>·hr-<NUM>·min-<NUM> for a specified period. The method comprises, after the specified period, flowing the liquid mixture through the membrane module under conditions such that the liquid mixture is separated into a permeate and a retentate.

Embodiments of the invention include a method of separating components of a liquid mixture. The method includes circulating the liquid mixture through one or more membrane modules. The method includes increasing circulating flow rate through the one or more membrane modules by <NUM> to <NUM>·hr-<NUM>·min-<NUM> per membrane module for a specified period. The method includes determining optimal conditions for separating the liquid mixture. The method includes, after the specified period, flowing the liquid mixture through the one or more membrane modules under the optimal conditions such that the liquid mixture is separated into a permeate and a retentate.

Embodiments of the invention include a method of separating components of a mixture of monoethylene glycol (MEG) and water. The method includes dynamically soaking one or more membranes of one or more membrane modules. The soaking comprises circulating the mixture through the one or more membrane modules. The soaking comprises increasing circulating flow rate through the one or more membrane modules by <NUM> to <NUM>·hr-<NUM>·min-<NUM> per membrane module for a specified period. The soaking further comprises adjusting conditions during the specified period based on measurements of temperature, pressure, and flow rates in the membrane during the specified period. The method includes determining, during the specified period, optimal conditions for separating the mixture. The method further includes, after the specified period, subjecting the membrane modules comprising the one or more membranes to a vacuum pressure and flowing the mixture through the one or more membrane modules under the optimal conditions such that the mixture is separated, by pervaporation and/or vapor permeation, into a first stream comprising primarily water and second stream comprising primarily MEG.

The terms "wt. %" or "mol. %" refer to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume, or the total moles of material that includes the component. In a non-limiting example, <NUM> moles of component in <NUM> moles of the material is <NUM> mol. % of component.

The terms "inhibiting" or "reducing" or "preventing" or "avoiding" or any variation of these terms, when used in the claims and/or the specification, include any measurable decrease or complete inhibition to achieve a desired result.

The term "primarily," as that term is used in the specification and/or claims, means greater than any of <NUM> wt. %, <NUM> mol. %, and <NUM> vol. For example, "primarily" may include <NUM> wt. % to <NUM> wt. % and all values and ranges there between, <NUM> mol. % to <NUM> mol. % and all values and ranges there between, or <NUM> vol. % to <NUM> vol. % and all values and ranges there between.

Other objects, features and advantages of the present invention will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not meant to be limiting.

Currently, distillation is used for separating liquid mixtures. However, distillation of liquid mixtures in certain circumstances, especially organic liquid and water, generally consumes a large amount of energy and requires multiple distillation columns in series due to the formation azeotropes between the components of the liquid mixture. Thus, the operational costs can be high when distillation is used for separating liquid mixtures of organic liquid and water. Membrane based technologies, including reverse osmosis, ultrafiltration, and/or nanofiltration, are also used for separating organic liquid and water. However, using these membrane based technologies in an industrial scale is challenging because of the limited separation factors (SF), prolonged start up procedure, and requirement of large membrane surfaces. The present invention provides a solution to these problems. The solution is premised on a method of separating components of a liquid mixture that includes a startup procedure for quick attainment of steady state. This can be beneficial for shortening the required time of the overall separation process. Furthermore, the disclosed method can further use a machine learning algorithm, an artificial intelligence, and/or neural network modeling to determine and adjust the startup conditions and operating conditions for the membrane based separation process, which can lead to improvement in separation efficiency, membrane lifetime, and purity of the products. These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.

In embodiments of the invention, the membrane based separation system for separating a liquid mixture can include one or more membrane modules, a feed vessel, a retentate vessel, and a vacuum pump. With reference to <FIG>, a schematic diagram is shown for system <NUM> that is capable of separating a liquid mixture with shortened start-up procedure and improved separation performance compared to conventional membrane based separation methods.

According to embodiments of the invention, system <NUM> comprises feed vessel <NUM>. Feed vessel <NUM> may be configured to store a liquid mixture. In embodiments of the invention, feed vessel <NUM> may comprise a hot oil unit configured to heat the liquid mixture therein to a target temperature. The liquid mixture may comprise <NUM> to <NUM> wt. % diol and <NUM> to <NUM> wt. In embodiments of the invention, the liquid mixture includes (<NUM>) a mixture of bisphenol A (BPA), Phenol, and/or water, (<NUM>) a mixture of tetrahydrofuran, methanol, and water, (<NUM>) a mixture of acetic acid, HCl, and water, (<NUM>) a mixture of toluene and water, (<NUM>) a mixture of dimethyl carbonate and methanol, (<NUM>) a mixture of methanol, toluene, and water, (<NUM>) a mixture of alcohol and water, (<NUM>) a mixture of ethylene glycol and water, or combinations thereof.

According to embodiments of the invention, an outlet of feed vessel <NUM> may be in fluid communication with membrane module <NUM> such that feed stream <NUM> comprising the liquid mixture flows from feed vessel <NUM> to membrane module <NUM>. In embodiments of the invention, feed pump <NUM> may be installed between feed vessel <NUM> and membrane module <NUM> configured to pump feed stream <NUM> from feed vessel <NUM> to membrane module <NUM>. Feed pump <NUM> may include a dynamic pump or a positive displacement pump. Non-limiting examples for the dynamic pump may include a centrifugal pump, a submersible pump, a hydrant booster pump, and combinations thereof. Non-limiting examples for the positive displacement pump may include a gear pump, a diaphragm pump, a peristaltic pump, a piston pump, a lobe pump, a pump produced by Julabo™ (U. ), and combinations thereof.

In embodiments of the invention, membrane module <NUM> is configured to separate feed stream <NUM> to form retentate stream <NUM> comprising a retentate and permeate stream <NUM> comprising a permeate. According to embodiments of the invention, membrane module <NUM> may include one or more membranes contained in a frame. Membrane module <NUM> may further include a membrane support adapted to support each membrane in membrane module <NUM>. The support may be disposed at a side of a membrane that is distal from feed stream <NUM>. Non-limiting examples of the membrane support may include polyvinyl alcohol, polysulfone, silica, polyimide, zeolite, zirconia, silicalite-<NUM>, ZSM-<NUM>, ceramic, and combinations thereof.

According to embodiments of the invention, the membranes of membrane module <NUM> may include one or more organic polymeric membranes, one or more organic ceramic membranes, one or more organic zeolite membranes, one or more organic hybrid membranes, or combinations thereof. Non-limiting examples of organic polymeric membranes include polyvinyl alcohol (PVA) membranes, chitosan membranes, polyamides membranes, polyimides membranes, polyacrylonitrile (PAN) membranes, polyacrylic acid membranes, cellulose acetate membranes, polydimethylsiloxane (PDMS) membranes, poly-block-ether-amides membranes, polyurethanes membranes, and combinations thereof. Non-limiting examples of ceramic membranes may include silica membranes, alumina membranes, zirconia membranes, and combinations thereof. Non-limiting examples of zeolite membranes may include hydrophilic membranes (e.g., zeolite NaA, Y), and hydrophobic membranes (e.g., silicalite-<NUM>, ZSM-<NUM>), and combinations thereof. Non-limiting examples of hydride membranes may include silica in polymeric matrix type of membranes (e.g., Hybrid Silica Hybsi® from ECN (Netherlands)), polymeric mixed matrix membranes (e.g., PDMS and polyetherimide membranes, and PVA and chistosan membranes), and combinations thereof. In embodiments of the invention, the membranes may be in the form of membrane tubes.

According to embodiments of the invention, an outlet of membrane module <NUM> is in fluid communication with an inlet of retentate vessel <NUM> such that retentate stream <NUM> flows from membrane module <NUM> to retentate vessel <NUM>. In embodiments of the invention, an outlet of membrane module <NUM> is in fluid communication with vacuum pump <NUM>. Vacuum pump <NUM> is configured to apply vacuum downstream of the membranes of membrane module <NUM> during separation of feed stream <NUM>. In embodiments of the invention, system <NUM> includes cold trap <NUM> installed upstream of vacuum pump <NUM> and downstream of membrane module <NUM>. Cold trap <NUM> may be in fluid communication with both vacuum pump <NUM> and membrane module <NUM>, and configured to condense permeate stream <NUM>.

According to embodiments of the invention, system <NUM> includes control module <NUM> comprising a feed forward loop configured to control the hot oil unit of feed vessel <NUM> for adjusting the temperature and/or temperature ramp of liquid mixture in feed vessel <NUM>. Control module <NUM> may be configured to control feed pump <NUM> for adjusting the flow rate and/or flow rate ramp of feed stream <NUM>. Control module <NUM> may be further configured to control pressure head generated by feed pump <NUM> and/or a recirculating flow booster. The pressure ramp can be a function of time. For instance, the pressure ramp can be a step change of pressure or rate of increase of pressure with time (i.e., exemplary units of pressure ramp may include bar/hour, bar/minute, bar/s, etc.). In embodiments of the invention, control module <NUM> is configured to take real time live measurements of one or more parameters in membrane module <NUM> and adjust parameters including temperature ramp, flow rate ramp, or pressure ramp rates based on the real time live measurements. Further, algorithms including statistical tools and artificial intelligence (AI) may be incorporated in control module <NUM>. The algorithms may be configured to use the real time data comprising the real time live measurements to predict the future data including the parameters in membrane module <NUM> and adjust the ramp rates of the parameters to turn the overall control system from feedback to feedforward control loops. In embodiments of the invention, control module <NUM> includes non-transitory storage medium configured to store one or more algorithms for pre-setting and/or optimizing a start-up procedure and/or operating conditions of system <NUM>. According to embodiments of the invention, the one or more algorithms of control module <NUM> is adapted to derive preliminary empirical equations that can be used in training test samples to simulate the membrane separation process at membrane module <NUM> and obtain optimized process conditions and ramp-up rates for start-up procedures of system <NUM>. The one or more algorithms may include a machine learning algorithm, an artificial intelligence algorithm, an advanced statistical tools based algorithm, a design of experiment algorithm (e.g., Box-Behnken Design), a hybrid pore-diffusion model based algorithm, a neural network based algorithm, a big data analytic algorithm, stochastic algorithm, spatial correlations based algorithm, best-fit (f-test, p-value based) algorithm, regression based algorithms (e.g., ordinal logistic, mixed-effects, random forest), or combinations thereof. In embodiments of the invention, the machine learning algorithm may include a supervised learning algorithm, an unsupervised learning algorithm, a reinforcement learning algorithm, a clustering technique based learning algorithm, or combinations thereof. In embodiments of the invention, the one or more algorithms are executed using input parameters of system <NUM> including but not limited to real-time monitored data of temperature, pressure head, vacuum pressure, permeate flow rate, retentate flow rate, temperature drop across the membrane module, feed concentration, retentate concentration, permeate concentration (all concentrations in weight basis %), thickness of scaling on outer/inner deposits, condenser/cooling water inlet and outlet temperatures, cooling water flow rate, or combinations thereof. In embodiments of the invention, real time data of the input parameters of system <NUM> are processed and analyzed by big data analytic algorithms of control module <NUM>. In embodiments of the invention, the one or more algorithms are capable of utilizing real time data of real time live measurement to optimize operating parameters in real time such that the temperature, pressure and/or flowrate ramp rates of membrane module <NUM> can reach maximize separation efficiency. The control loop can be transformed to feedforward control from feedback mode wherein the optimized parameters can be predicted ahead of time and fitted with real time measurements in order to auto-correct the model coefficients/constants in real time. The final goal of the algorithms can include making the feedforward control system (for system <NUM>) reach optimal steady state in a shorter time compared to conventional systems, enabling dynamic soaking (where membrane is treated with process fluid/feed itself with optimal process ramp rates including temperature ramp, pressure ramp, flow rate ramp, etc.) and optimizing the separation efficiency via increasing the flux and permeate purity in high magnitudes (e.g., ~<NUM> to <NUM> times the flux, with ><NUM>% permeate purity) compared to conventional processes that utilize feedback control loops.

In embodiments of the invention, a hybrid pore diffusion model is used for building a model for membrane based separation using system <NUM>. The hybrid pore diffusion model can be derived by using both solution-diffusion model and the pore flow model to obtain an equation for permeate flux. According to embodiments of the invention, the hybrid pore diffusion model is based on pre-assumption that components could be in liquid phase or vapor phase and the state of the components in the membrane is determined by assuming an imaginary phase for the components. In the hybrid pore diffusion model, according to embodiments of the invention, when the pressure of the imaginary phase exceeds the saturation pressure of the diffusing components, it is in liquid state. The imaginary phase can be in vapor state when the imaginary phase has a pressure less than the saturation pressure. The flux and concentration in the membrane phase can be considered to follow the solution-diffusion model when it was liquid. In embodiments of the invention, in the membrane phase corresponding to the liquid section, the diffusivity is independent from concentration, whereas, in the vapor section, the diffusivity can be considered to be increasing exponentially with concentration. Total flux of a membrane based on the hybrid model can be expressed by the following equation. <MAT> Where J is permeation flux (kmol·m-<NUM>·s-<NUM> or kg·m-<NUM>·h-<NUM>), Amix is liquid phase transport parameter of mixed feed (kmol·m-<NUM>·s-<NUM>·mmHg-<NUM>), <IMG> is the distance (m) from feed-membrane interface to liquid section, <IMG> is the distance (m) from feed-membrane interface to vapor section , P<NUM> is pressure of feed stream, P* is saturation pressure at vapor-liquid interface, Bi is vapor phase transport parameter (kmol·m-<NUM>·s-<NUM>·mmHg-<NUM>) for component i (e.g., ethanol), Pi,* is saturation pressure of component i at vapor-liquid interface, Pi,<NUM> is partial pressure of component j (e.g., water) in the permeate, Bj is vapor phase transport parameter (kmol·m-<NUM>·s-<NUM>·mmHg-<NUM>) for component j, Pj,* is saturation pressure of component j at vapor-liquid interface, and Pj,<NUM> is partial pressure for component j in the permeate.

Methods of separating components of a liquid mixture using a membrane based separation system have been discovered. The methods may include a quick start-up procedure for reaching steady state, thereby shortening the operation process compared to the conventional methods. The methods may include the liquid mixture being separated under optimized conditions that are provided and being adjusted by the control module using various algorithms, resulting in the improved separation performance and prolonged membrane lifetime.

As shown in <FIG>, embodiments of the invention include method <NUM> for separating components of a liquid mixture. Method <NUM> may be implemented by system <NUM>, as shown in <FIG> and described above. According to embodiments of the invention, as shown in block <NUM>, method <NUM> comprises circulating the liquid mixture through the one or more membranes of membrane module <NUM>. The circulating at block <NUM> may be configured to dynamically soak the one or more membranes of membrane module <NUM> in the liquid mixture.

According to embodiments of the invention, as shown in block <NUM>, method <NUM> comprises increasing circulating flow rate through the one or more membranes at a flow rate ramp for a specified period. In embodiments of the invention, the membranes in membrane module <NUM> are in form of membrane tubes. An initial flow rate of the liquid mixture at a beginning of the specified period may be in a range of <NUM> to <NUM>·hr-<NUM> per membrane tube and all ranges and values there between including ranges of <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, <NUM> to <NUM>·hr-<NUM>, and <NUM> to <NUM>·hr-<NUM>. The flow rate ramp during the specified period at block <NUM> may be in a range of <NUM> to <NUM>·hr-<NUM>·min-<NUM> and all ranges and values there between including ranges of <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, <NUM> to <NUM>·hr-<NUM>·min-<NUM>, and <NUM> to <NUM>·hr-<NUM>·min-<NUM>. In embodiments of the invention, the flow rate ramp is determined and/or adjusted by the one or more algorithms of control module <NUM>.

The specified period (soaking time) may be <NUM> to <NUM> hours. Once steady state is reached after the specified period, the same final set-point flow rate can be maintained at <NUM> to <NUM>·hr-<NUM> per membrane (tube). In embodiments of the invention, the range of the specified period can be determined and/or adjusted by control module <NUM>. According to embodiments of the invention, as shown in block <NUM>, method <NUM> further comprises, during the specified period, increasing a temperature of the liquid mixture at a temperature ramp range of <NUM> to <NUM> /min and all ranges and values there between including ranges of <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, <NUM> to <NUM>/min, <NUM> to <NUM> /min, <NUM> to <NUM> /min, and <NUM> to <NUM> /min. An initial temperature of the liquid mixture at a beginning of the specified period may be in a range of <NUM> to <NUM> and all ranges and values there between including ranges of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, and <NUM> to <NUM>. In embodiments of the invention, during the specified period, the temperature ramp range is determined and/or adjusted by the one or more algorithms of control module <NUM>. In embodiments of the invention, a final temperature of the liquid mixture at steady state may be in a range of <NUM> to <NUM> and all ranges and values there between including ranges of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, and <NUM> to <NUM>.

According to embodiments of the invention, as shown in block <NUM>, method <NUM> further comprises, during the specified period, adjusting a pressure drop between inlet and outlet tapping points of membrane module <NUM> such that the pressure drop ramp rate through one or more membranes of membrane module <NUM> is in a range of <NUM> to <NUM> bar/hr increase per membrane (tube) and all ranges and values there between including ranges of <NUM> to <NUM> bar/hr , <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, <NUM> to <NUM> bar/hr, and <NUM> to <NUM> bar/hr. In embodiments of the invention, a steady state is reached at one or more membranes of membrane module <NUM> during and/or at the end of the specified period. In embodiments of the invention, the steady state is a state at which all state variables (e.g., flow rate, temperature, and pressure across membrane module <NUM>) of system <NUM> are substantially constant or constant and continue to be substantially constant or constant unless some external perturbation to system <NUM> occurs. In embodiments of the invention, steps of block <NUM> to block <NUM> are capable of shortening duration required for reaching steady state at one or more membranes of membrane module <NUM> compared to soaking the one or more membranes in a non-circulating liquid mixture.

According to embodiments of the invention, as shown in block <NUM>, method <NUM> comprises, after the specified period, flowing feed stream <NUM> comprising the liquid mixture through the one or more membranes of membrane module <NUM> under conditions such that the liquid mixture is separated into permeate stream <NUM> comprising a permeate and retentate stream <NUM> comprising a retentate. In embodiments of the invention, the flowing at block <NUM> may be initiated by applying vacuum by vacuum pump <NUM> to the one or more membranes of membrane module <NUM>. According to embodiments of the invention, the conditions at block <NUM> are determined and/or optimized by the one or more algorithms of control module <NUM>.

In embodiments of the invention, the conditions at block <NUM> include a temperature of the liquid mixture in a range of <NUM> to <NUM> and all ranges and values there between including ranges of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, and <NUM> to <NUM>. The conditions at block <NUM> may include an operating pressure of <NUM> to <NUM> bar and all ranges and values there between including ranges of <NUM> to <NUM> bar, <NUM> to <NUM> bar, <NUM> to <NUM> bar, <NUM> to <NUM> bar, <NUM> to <NUM> bar, and <NUM> to <NUM> bar. In embodiments of the invention, the conditions at block <NUM> include a flow rate of feed stream <NUM> in a range of <NUM> to <NUM>/hr per membrane module and all ranges and values there between including <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, <NUM> to <NUM>/hr, and <NUM> to <NUM>/hr. In embodiments of the invention, at block <NUM>, the conditions includes applying a vacuum to the one or more membranes of membrane module <NUM> with a vacuum pressure of <NUM> to <NUM> mbar and all ranges and values there between including ranges of <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, <NUM> to <NUM> mbar, and <NUM> to <NUM> mbar. Starting pressure of membrane module <NUM> before applying vacuum may be about <NUM> bar. A pressure ramp (decreasing ramp) of membrane module <NUM> may be in a range of <NUM> to <NUM> mbar per minute and all ranges and values there between including ranges of <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, <NUM> to <NUM> mbar/min, and <NUM> to <NUM> mbar/min. In embodiments of the invention, method <NUM> is used for separating water and monoethylene glycol and permeate stream <NUM> produced by method <NUM> comprises at least <NUM>% water.

According to embodiments of the invention, method <NUM> can be used to replace one or more steps in diol manufacturing plant(s), including diol dehydration-CO<NUM> vent water purification, condensate water purification, overhead ethylene glycol separation, water separation from reactor effluent, aldehydes and acids separation section, de-ionizing unit in cycle water stream. According to embodiments of the invention, method <NUM> is capable of producing purified concentrated diol/polyols and improving ultraviolet transmittance of water. In embodiments of the invention, the water purified using method <NUM> has an ultraviolet transmittance greater than <NUM>% at <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. In embodiments of the invention, method <NUM> is capable of reducing total dissolved solids (TDS) in water, improving pH value of water, reducing (permeate) water conductivity and aldehyde contents in water. The permeate water produced by method <NUM> may be utilized as cycle water in glycol plants or a treated process water in other chemical plants and/or manufacturing units.

Although embodiments of the present invention have been described with reference to blocks of <FIG>, it should be appreciated that operation of the present invention is not limited to the particular blocks and/or the particular order of the blocks illustrated in <FIG>. Accordingly, embodiments of the invention may provide functionality as described herein using various blocks in a sequence different than that of <FIG>.

The systems and processes described herein can also include various equipment that is not shown and is known to one of skill in the art of chemical processing. For example, some controllers, piping, computers, valves, pumps, heaters, thermocouples, pressure indicators, mixers, heat exchangers, and the like may not be shown.

As part of the disclosure of the present invention, specific examples are included below. The examples are for illustrative purposes only and are not intended to limit the invention. Those of ordinary skill in the art will readily recognize parameters that can be changed or modified to yield essentially the same results.

A liquid mixture of monoethylene glycol and water was separated using a Pervatech® membrane at a pilot plant. Each membrane module in the pilot plant included <NUM> membrane tubes. Each membrane tube had an outer diameter of <NUM> and inner diameter of <NUM>. The wall thickness for each membrane tube was <NUM>. The contacting area of each membrane tube was about <NUM><NUM>. The feed concentration of monoethylene glycol was in a range of <NUM> to <NUM> wt. The flowrate was in a range of <NUM> to <NUM>/hr. The feed temperature was in a range of <NUM> to <NUM>. The feed pressure was set in a range of <NUM>-<NUM> bar. The vacuum on the permeate was in a range <NUM> to <NUM> mbar. Cooling water used for recovering the permeate was at about <NUM>. Simulations on the separation process were also performed in Aspen (versions <NUM> and <NUM>), ACM-Aspen Custom Modeler. Statistical modeling was performed in GAMS and JMP.

The experimental results are shown in Tables <NUM> and <NUM>. Table <NUM> shows the experimental results of membrane separation without rapid startup and non-dynamic soaking. Table <NUM> shows the experimental results of membrane separation with rapid startup and dynamic soaking. Table <NUM> shows the simulation results of rapid start-up and dynamic soaking.

Claim 1:
A method of separating components of a liquid mixture containing <NUM>-<NUM> wt.% diol and <NUM>-<NUM> wt.% water, the method comprising:
a) dynamically soaking one or more membranes of one or more membrane modules, wherein the one or more membranes are adapted to perform pervaporation, by:
i) circulating the liquid mixture through one or more membranes of a membrane module;
ii) increasing circulating flow rate through the membrane module at a flow rate ramp range of <NUM> to <NUM>·hr-<NUM>·min-<NUM> per membrane module for a specified period; and
iii) during the specified period, increasing a temperature of the circulating liquid mixture at a temperature ramp range of <NUM> to <NUM> /min;
b) determining, during the specified period, optimal conditions for separating the liquid mixture, wherein the optimal conditions for separating the liquid mixture are determined by a machine learning algorithm, an artificial intelligence algorithm, and/or neural network modeling, and wherein the optimal conditions include a temperature of the liquid mixture in a range of <NUM> to <NUM> and an operating pressure of <NUM> to <NUM> bar; and
c) after the specified period, flowing the liquid mixture through the membrane module under conditions such that the liquid mixture is separated into a permeate comprising at least <NUM> wt.% water and a retentate, wherein the conditions in the flowing step include applying vacuum to the one or more membranes at a vacuum pressure of <NUM> to <NUM> mbar with ramp rate of <NUM> to <NUM> mbar per minute.