Can membrane technology be applied to ethylene glycol enrichment?

Using nanofiltration, reverse osmosis, and the like might not work anymore. I wonder if other membrane technologies will work?

A hydrophobic membrane can be used to adsorb and separate ethylene glycol, and enrichment can be achieved by measuring the ethylene glycol that passes through!

In fact, pervaporation membranes can do this, but industrialized membranes are still an issue! !

If (hydrophilic) pervaporation is used to separate ethylene glycol from water, the current investment requirements are estimated to be more than twice those of distillation, and the operating costs are even higher than those of distillation.

I really haven’t come across any cases of enrichment using ethylene glycol membrane separation, nor have I seen anyone do it. Could that experienced person please explain what kind of membrane to use and what the results will be like? If you want to give it a try, then find an infiltration tank to conduct experiments on your own

My idea is: if the concentration of the synthesized ethylene glycol is 10%–20%, use a membrane-based multi-stage multi-effect evaporation process to pre-concentrate it to 30%–40%； Then it is concentrated to 99% using conventional multi-effect evaporation or vacuum distillation (? ? ), if the concentration of the synthesized ethylene glycol is already 20% – 40%, conventional multi-effect evaporation can be used directly; the resulting dilute aqueous solution containing ethylene glycol (0.2 – 10%) can then be concentrated using membrane-based multi-stage multi-effect evaporation. By following this approach, the amount of 150-degree steam required to process one ton of liquid material throughout the entire process will not exceed 0.5 tons.

Hydrophobic film? Due to the surfactant properties of ethylene glycol, I’m afraid the pores will get saturated, right?

Only a pervaporation membrane can achieve this, and our company’s inorganic ceramic pervaporation membranes have been put into industrial use. Patent for a method of producing anhydrous ethanol through biomass fermentation and membrane pervaporation: 03113440.8 This invention relates to a method for producing anhydrous ethanol via biomass fermentation and membrane pervaporation, and proposes a production process that integrates biomass fermentation with pervaporation (PV) and vapor penetration (VP) technologies. The fermentation broth containing a low concentration of ethanol in the fermenter is drawn out, and ethanol is allowed to pass through microfiltration membranes and permeable ethanol membranes to concentrate it to a concentration of 40–95 wt% ethanol. Depending on the concentration of the broth drawn out, this concentrated solution can either be directly fed into an inorganic water-permeable membrane separator for water removal by osmosis, or it can first be subjected to preliminary distillation for further concentration before being fed into the inorganic water-permeable membrane separator to remove the remaining water, thereby yielding an anhydrous ethanol product with a concentration of ≥99.5 wt%. This invention combines ethanol fermentation with inorganic membrane pervaporation and steam permeation technologies, thereby reducing the inhibitory effect of ethanol during the fermentation process, increasing production capacity, saving energy consumption in production, and **reducing the production cost of ethanol.

“It can only be achieved through pervaporation membranes, and our company’s inorganic ceramic pervaporation membranes have already been put into industrial use” – this statement is debatable. For low concentrations of ethylene glycol, concentration can be achieved using distillation, multi-effect evaporation, membrane distillation, and membrane-assisted multi-effect evaporation, and all of these methods work well. Vacuum distillation is a mature technology for high glycol concentrations, and its energy consumption is not very high. Even though all distillation processes are energy-intensive, the number of theoretical stages required for the separation of the ethylene glycol-water system is low, which is determined by the difference in boiling points between water and ethylene glycol. Glycerol, ethylene glycol, and formamide are well-known organic solvents with high polarity, high boiling points, high surface tension, and high viscosity. If (hydrophilic) pervaporation is used to remove water from high-concentration ethylene glycol aqueous solutions, the viscosity of these high-concentration ethylene glycol solutions is very high, and concentration polarization becomes severe when operating at low temperatures (below 60 degrees). If a high-temperature heat source is used, the advantages of pervaporation no longer exist. If even methanol, which has a lower polarity than ethylene glycol, can be separated from water without permeate vaporization, is it really necessary to use permeate vaporization for the separation of ethylene glycol and water?

The 11th floor is talking about ethanol, not ethylene glycol, which is irrelevant to this topic.