An improved method is described for producing polylactide (PLA) whereby various gas streams containing lactide, lactic acid and water are recovered, are sent onto an assembly of packed columns for condensation, are brought into contact with a fluid at least comprising water, lactic acid and dissolved lactide; the fluid leaving the assembly of packed columns is recovered and is or is not filtered, the aqueous solution obtained via at least one exchanger is heated and sent into a feed tank under agitation which is continuously fed with a lactic acid solution, and hydrolysis of the lactide contained in the aqueous solution is performed in this feed tank.

A temperature gradient chromatography, and apparatus for the same, said method comprising the following: a) dissolving a composition comprising at least one polymer in at least one solvent, to form a polymer solution; b) injecting at least a portion of the polymer solution onto a support material and wherein the support material has a CI from 0.70 to 1.50; c) cooling the support material at a rate greater than, or equal to, 0.2? C./min; d) increasing the temperature of the support material to elute at least some of the polymer; e) generating the chromatogram.

A desalinating system and process is disclosed. The desalination system comprises using a freeze or fast-cooling process to freeze saline water droplets in a controlled manner that provides for diffusion of salt ions to a center of each frozen saline water droplet and formation of salt crystals surrounded by pure water crystals. The pure water crystals and salt crystals are subsequently separated in an ice melter using heat exchange to form a pure water stream.

A method is disclosed for purifying, by direct osmosis, a first liquid including water and at least one impurity, in which the method comprises the consecutive steps of: contacting the first liquid with a first side of a semi-permeable membrane, a second aqueous liquid containing an osmotic agent being in contact with the second side of the semi-permeable membrane, whereby water is extracted by direct osmosis from the first liquid through the semi-permeable membrane and passes into the second liquid containing the osmotic agent; forming clathrates hydrates of a host molecule in the second liquid containing the osmotic agent into which the water has passed; separating the clathrates hydrates from the second liquid containing the osmotic agent; and dissociating the separated clathrates hydrates to obtain pure water and the host molecule.

A crystallizer for use in treating produced water is disclosed. The crystallizer is a combination of a source of nitrogen in fluid communication with at least one connecting tube which is in fluid communication with a chamber which is in fluid communication with a discharge tube. The produced water from an oil and gas operation is fed into the crystallizer which will separate out contaminants from the water producing fresh water.

A method and crystallizer for treating produced water through the steps of feeding produced water to a porous pipe in a chamber wherein the chamber is cylindrically shaped having an interior wall with a top and a bottom; feeding gaseous nitrogen to a nozzle present in the chamber, which is in fluid communication with an interior pipe; feeding the produced water to the interior pipe wherein slush is formed in the pipe and this slush is forced through the interior pipe to the top of the chamber; operating at least one scraper which is mounted circumferentially about the porous pipe and having arms that extend outwardly from the scraper center in contact with the interior wall of the chamber wherein the scraper will remove salt crystals from the interior walls of the chamber; recovering salt crystals from the bottom of the chamber; and recovering fresh water from the chamber.

A method for treating produced water from a fracking operation is disclosed. The produced water is first fed to a compact separator for the removal of suspended materials. This produced water is then treated for dissolved gases and suspended oils before being fed to a crystallizer where salts are separated from the produced water thereby producing fresh water for reuse or other means. Alternatively, the produced water may be fed to a disinfection system and a concentrator depending upon the composition of the produced water.

A MEG reclamation process includes the step of increasing above 2,000 ppm the divalent metal salts concentration of a rich (wet) MEG feed stream flowing into a precipitator. The increasing step includes routing a salts-saturated MEG slipstream from the flash separator it to the precipitator. The slipstream may be mixed with a fresh water feed stream, a portion of the rich MEG feed stream, or some combination of the two. The rich MEG feed stream also may be split into two streams, with a portion of the stream being heated and routed to the flash separator and the other portion being combined as above with the removed slipstream. The process can be performed on the slipstream after dilution and prior to entering the precipitator or after being loaded into the precipitator. Removal of the insoluble salts may be done in either a batch or continuous mode.

A wastewater purifier has a chamber having an upper ingress end and a lower drain end, one or more wastewater nozzles connected to a wastewater source positioned near the ingress end, to produce wastewater droplets, a chilled air ingress positioned near the ingress end, connected to a chilled air source, positioned to permit the chilled air to mix with the wastewater droplets, a perforated accumulator near the drain end adapted to collect frozen droplets, a drain below the accumulator, and an egress for the chilled air near the drain end. A wastewater purifier has an elongated flow chamber having an upper portion and lower portion, one or more wastewater nozzles positioned near the upper portion, one or more egress vents positioned near the upper portion, a perforated accumulator at the bottom of the chamber, and a chilled air ingress connected between the upper and lower portions.

A desalinating system and method is disclosed. The desalination system comprises using a turbo freeze or fast-cooling process to freeze saline water droplets and separate salt crystals from pure water crystals, wherein said system provides for simultaneous injection of saline water droplets and a chilled refrigerant into a freezing chamber at a slip velocity sufficient to reduce the size of the saline water droplets to an optimal diameter.