A process for purifying a compound of formula 1,

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includes the following steps: a) adding an acid to an aqueous solution of the compound of formula 1, including salts and hydrates thereof so as to obtain a slurry having a pH3; and b) filtering the slurry and at least one time washing the obtained precipitate with a liquid comprising water; and c) dissolving the precipitate obtained in step b) in water to obtain an aqueous solution; and d) filtering of the solution obtained in step c) over a nanofiltration membrane having a Molecular Weight Cut Off in the range from 150 to 500 and wherein optionally, between step c) and step d) the pH of the aqueous solution is adjusted to a pH value in the pH range as specified by the manufacturer of the nanofiltration membrane. A process for preparing a gadolinium complex of the purified compound of formula 1 is also disclosed. This gadolinium complex can be used for making a pharmaceutical composition as a contrast agent for magnetic resonance imaging.

The combination multi-effect distillation and multi-stage flash evaporation system integrates a multi-stage flash (MSF) evaporation system with a multi-effect distillation (MED) system such that the flashing temperature range of the MSF process is shifted upward on the temperature scale, while the MED distillation process operates in the lower temperature range. The multi-stage flash evaporation system includes a plurality of flash evaporation/condensation stages, such that the multi-stage flash evaporation system receives a volume of seawater or brine from an external source and produces distilled water. The multi-effect distillation system includes a plurality of condensation/evaporation effects, such that the multi-effect distillation system receives concentrated brine from the multi-stage flash desalination system and produces distilled water.

A system for continuously treating water with residual oil and/or solids includes a treatment system with inline mixers. A pH adjustment fluid may be added to the water in a first inline mixer. A micro-encapsulating flocculating dispersion flocculant may be added in a second inline mixer. The addition of the micro-encapsulating flocculating dispersion flocculant may cause flocculation of residual oil and/or solids in the water to form a pin flocculant. An activator may be added in a third inline mixer and a conditioner may be added in a fourth inline mixer. Bulk flocculant may be formed from the pin flocculant after the addition of the conditioner. The resultant mixture may flow to a settling tank where the flocculants may settle to produce treated water. After settling, the treated water may flow through a mechanical filter and/or a sorption filter to produce water suitable for desalination and/or other downstream processes.

A new apparatus, system and method to purified produced water and removed valuable metals and minerals is described. The apparatus comprises a device for flowing produced water wellbore from a wellbore to the produced water purification apparatus; at least one device to remove heavy metals from the produced water; at least one brine removal device to remove brine from the produced water. The method comprises steps to use the apparatus and the system comprises a control panel that operates the at least one device for removing heavy metals and at least one sensor in a coordinated manner.

A desalination system, including a membrane distillation portion, a solar power concentration portion, and a thermal vapor compression portion operationally connected to the membrane distillation portion and to the solar power concentration portion. The membrane distillation portion includes a first vessel having a first portion and a second portion separated by a hydrophobic membrane operationally connected therebetween and oriented to pass water from the first portion to the second portion, wherein the hydrophobic membrane further comprises a hydrophilic membrane and an air blocking layer connected to the hydrophilic membrane and disposed in the first portion, a vacuum gap adjacent the hydrophobic membrane and disposed in the second portion, a first fluid inlet and a first fluid outlet operationally connected to the first portion, and a second fluid inlet and a second fluid outlet operationally connected to the second portion. The solar power concentration portion includes a pump having a pump outlet and a pump inlet operationally connected to a water line and to the vacuum gap, a linear Fresnel mirror collector for collecting and focusing sunlight, and an outlet line operationally connected to the pump outlet and positioned to receive focused sunlight from linear Fresnel mirror collector. The thermal vapor compression portion includes an ejector having an ejector inlet portion and an ejector outlet portion, wherein the ejector inlet portion is operationally connected to the outlet line and to the vacuum gap, a second vessel fluidically connected to the outlet portion and further including a heat exchanger operationally connected to the ejector outlet portion and to a water pipe, a feed spray operationally connected to the second outlet and positioned to spray into the heat exchanger, and a collection portion for receiving concentrated feed spray. The heat exchanger receives desalinated water from the ejector and from the feed spray. The water line carries desalinated water from the heat exchanger. The first outlet passes concentrated brine, and the first inlet receives feed water to be desalinated.

A purification method for separating and purifying an organic solvent from a liquid mixture of an organic solvent and water, the organic solvent having a boiling point of more than 100 C. at 1 atm, includes the steps of: passing the liquid mixture through a first ion exchange device; supplying the liquid mixture discharged from the first ion exchange device to a pervaporation device to selectively separate water component; supplying the organic solvent recovered from the concentration side of the pervaporation device to an evaporator to obtain a purified organic solvent; and passing, through the second ion exchange device, a portion of liquid containing the organic solvent and flowing at a first position subsequent to the first ion exchange device. The liquid discharged from the second ion exchange device is returned to a second position which is at a preceding stage of the pervaporation device.

There are provided processes for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium, copper, magnesium and aluminum, the process comprising:

reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium, copper, magnesium and aluminum with lithium hydroxide, sodium hydroxide and/or potassium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate;

separating the liquid and the solid from one another to obtain the metal hydroxide;

submitting the liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate to an electromembrane process for converting the lithium sulfate, sodium sulfate and/or potassium sulfate into lithium hydroxide, sodium hydroxide and/or potassium hydroxide respectively;

reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate; and

reusing the lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate and/or with the metal hydroxide.

A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

A process for purifying a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant, comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.

The present invention relates to a system for jointly producing erythritol and liquid sorbitol by using a corn starch, including a liquefaction tank, a saccharification tank, a filter and a nanofiltration assembly. The liquefaction tank is used to perform liquefaction for the corn starch, the saccharification tank is used to perform saccharification for the liquefied material, the filter is used to filter out impurities in the saccharified material to obtain a glucose liquid, and the nanofiltration assembly is used to perform nanofiltration for the filtered glucose liquid to respectively obtain a dialysate and a concentrate. The system further includes a fermentation and crystallization assembly for performing fermentation and crystallization for the dialysate to prepare crystalline erythritol, and a hydrogenation and evaporation assembly for performing hydrogenation and evaporation for the concentrate to prepare liquid sorbitol. The present invention further provides a method of jointly producing erythritol and liquid sorbitol by using a corn starch. The present invention not only improves the purity of erythritol but also obtains liquid sorbitol, thus improving the utilization value of the corn starch.