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.

One exemplary embodiment can be a process for oxidizing one or more thiol compounds from an alkaline stream. The process may include passing a mixed stream having the alkaline stream to a vessel having an oxidation section, a separation section and a vent gas section. Often, the oxidation section includes a body containing one or more packing elements. The process can further include passing an oxidized alkaline stream to the separation section containing a first chamber and a second chamber. Usually, the first chamber contains a coated mesh and packing. The two sections further form a neck contains a packing, a distributor, and a mesh.

A cooling tower is provided having a heat exchange section, and a fan for moving air through the heat exchange section. A water distribution assembly provides water onto and through the heat exchange section. An air inlet section is provided through which air is drawn into the cooling tower and the heat exchange section. The air inlet section has outside edges and corners. A wall assembly is provided in the air inlet section, with the wall assembly extending from the corners of the air inlet section inwardly. The water passing through the heat exchange section enters the air inlet section, and exits to a sump beneath the air inlet section. The air inlet section is comprised of a structure having outside edges and corners, and the wall assembly is comprised of a plurality of wall panel sections. Each wall panel section has an outer edge at a corner of the air inlet section, and each wall panel section extends inwardly from the corner of the air inlet section.

A method for removing dissolved hydrocarbons from water may comprise: cracking a mixed hydrocarbon stream in a cracking furnace to produce a cracked gas effluent; quenching the cracked gas effluent in a quench water tower with quench water to produce a quenched gas stream and a spent quench water stream comprising water, tars, heavy aromatic hydrocarbons, gasoline, dissolved oil, and dispersed oil; feeding the spent quench water stream to a liquid-liquid extraction unit wherein the liquid-liquid extraction unit removes at least a portion of the dissolved oil and produce an extracted effluent stream.

A method for removing dissolved hydrocarbons from water may comprise: cracking a mixed hydrocarbon stream in a cracking furnace to produce a cracked gas effluent; quenching the cracked gas effluent in a quench water tower with quench water to produce a quenched gas stream and a spent quench water stream comprising water, tars, heavy aromatic hydrocarbons, gasoline, dissolved oil, and dispersed oil; feeding the spent quench water stream to a liquid-liquid extraction unit wherein the liquid-liquid extraction unit removes at least a portion of the dissolved oil and produce an extracted effluent stream.

A process is presented for the removal or aromatics from a hydrocarbon stream. The hydrocarbon stream is generated by a dehydrogenation process that generates aromatics. The process includes a two contact cooler system with the first and second contact coolers using different coolants. The second coolant is a non-aromatic hydrocarbon coolant that will absorb aromatics.

Condensing apparatuses and their use in various heat and mass exchange systems are generally described. The condensing apparatuses, such as bubble column condensers, may employ a heat exchanger positioned external to the condensing vessel to remove heat from a bubble column condenser outlet stream to produce a heat exchanger outlet stream. In certain cases, the condensing apparatus may also include a cooling device positioned external to the vessel configured and positioned to remove heat from the heat exchanger outlet stream to produce a cooling device outlet stream. The condensing apparatus may be configured to include various internal features, such as a vapor distribution region and/or a plurality of liquid flow control weirs and/or chambers within the apparatus having an aspect ratio of at least 1.5. A condensing apparatus may be coupled with a humidifier to form part of a desalination system, in certain cases.

A method and apparatus for purifying a fluid are disclosed. An evaporation unit and a condensing unit are employed. Each unit has a chamber and a plurality of spaced-apart fragmentation plates, each plate spanning at least a part of the width of the chamber and each defining the upper limit of an evaporation zone or condensation zone. Each evaporation zone is provided with a fluid vapour outlet and each condensation zone is provided with a fluid vapour inlet. The evaporation and condensation zones operate at different temperatures. The fluid vapour outlet of the evaporation zone operated at the highest temperature is connected to the fluid vapour inlet of the condensation zone operated at the highest temperature, and the fluid vapour outlet of the evaporation zone operated at the lowest temperature is connected to the fluid vapour inlet of the condensation zone operated at the lowest temperature.

A pyrolysis vapour condenser system (1) and a method for condensing pyrolysis vapour, the pyrolysis vapour condensing system comprising a condenser vessel (2), comprising a vapour inlet (3), and a cleaning device (9) for removing deposits from the vapour inlet (3). The cleaning device (9) is moveable between a cleaning position, in which it is disposed at least partially in the vapour inlet (3) for cleaning it, and a retracted position, in which the cleaning device (9) is retracted away from the vapour inlet (3) towards the condenser vessel (2).