The disclosure pertains to a urea plant and process of the thermal stripping type as well as to a method of modifying a urea plant of the thermal stripping type. Provided is a urea plant with a thermal stripper and a high pressure carbamate condenser with a shell space wherein gas from the stripper is condensed in the shell space.

The present invention relates to a method and an apparatus for producing an -olefin low polymer by subjecting an -olefin to low polymerization reaction in the presence of a catalyst in a liquid phase part within a reactor, and the present invention relates to a method and an apparatus for producing an -olefin low polymer, such as 1-hexene, etc., by subjecting an -olefin, such as ethylene, etc., to low polymerization reaction, in which the formation of a polymer on an upper tube plate surface of a shell and tube type heat exchanger that is used for heat removal is suppressed, thereby performing a continuous operation stably over a long period of time.

A short-path distillation apparatus and method of operation are described. An example short-path distillation apparatus includes a double-walled bulb-shaped condensing head. The double wall forms a coolant chamber that substantially envelopes an inner condensate chamber. Coolant is introduced into and removed from the coolant chamber via ports in the outer wall of the head. Condensate in gaseous form is introduced into the condensate chamber where it comes in contact with and condenses as distillate upon the cold inner surface of the condensate chamber. Condensed distillate travels down the inner surface of the condensate chamber and then into a distillate outlet conduit that transports the condensed distillate to a collection vessel.

Methods, apparatus, and processes are provided for a condenser including flowing a vapor stream including formaldehyde into a tube bundle in a vertical upflow reflux condenser, where a tube in the tube bundle has a length to outside diameter ratio of greater than about 170:1, flowing a cooling fluid on a shell-side of the vertical upflow reflux condenser to condense at least a portion of the vapor stream, where the condensed portion of the vapor stream forms a wetted tube internal surface area on each tube in the generally upright tube bundle; and maintaining the vapor stream velocity at a rate that provides a liquid residence time where formaldehyde condensed on the wetted internal surface area of each tube can react with water to form methylene glycol, removing at least sixty percent (60%) of formaldehyde from the vapor stream fed to the condenser.

In an improved method of distilling fluids, some or all of the fluid is recovered as distillate and the fluid is situated in the shell side of a first shell and tube heat exchanger. The fluid to be recovered as distillate is successively boiled, demisted, compressed and then introduced into upper ends of the tubes. A second shell and tube heat exchanger is located below the first heat exchanger, and distillate from upper ends of the tubes in the second heat exchanger are arranged to receive distillate liquid and/or vapor from the lower ends of tubes of the first heat exchanger. The fluid is located in the shell of the second heat exchanger and that fluid is heated but is not boiled. A mechanism is provided to supply at least some of the heated fluid to the shell of the first heat exchanger.

A process for cooling quench effluent includes providing a quench column effluent to a quench column aftercooler condensate; cooling the quench column effluent to provide a quench column aftercooler condensate; and recirculating at least a portion of the quench column aftercooler condensate to the quench column aftercooler at a rate to prevent fouling of the quench column aftercooler.

A heat exchanger includes a shell, and a tube assembly disposed in the shell, the tube assembly including at least one tube, wherein the tube has a pair of end sections having a first diameter and a central section extending between the end sections having a second diameter that is greater than the first diameter.

The present disclosure relates to a process for preparing polymers using a plug flow reactor. The process includes providing an aqueous monomer solution comprising amide monomers; evaporating the aqueous monomer solution to form a concentrated monomer solution; and polymerizing the concentrated monomer solution in a plug flow reactor comprising a shell side and a tube side to form a first process fluid comprising polymers. The concentrated monomer solution flows on the shell side from the inlet to the outlet.

The present invention relates to an olefinic monomer recovery device capable of suppressing fouling and pressure drop in the recovery device in a process of separating and recovering unreacted monomers after production of a polyolefin resin. The olefinic monomer recovery device is used for separating and recovering unreacted olefinic monomers after production of a polyolefin resin, the apparatus comprising a vertical-type heat exchange unit, and a knock-out drum unit.

Improvements in grain alcohol distillation plants by incorporating a novel internal arrangement in the wort column and the rectifying column with distributors and accumulators inside thereof, achieving a stable and safe process in wide ranges of operation, guaranteeing the productivity of the plant and the quality of the products. The wort column features detachable perforated plates, easy to access and clean through manholes. By having easily detachable plates and, also, a manhole for each plate with holder type connections, the access to the interior of the column for cleaning and maintenance purposes is facilitated. The rectifying column is a special filling column with flow distributors, it has an intermediate alcohol accumulator and a condenser which is an integral part of the column that prevents the use of pumps. The arrangement of distributors and accumulators within the rectifying column favors the operational stability of the plant, allowing a low scale equipment to work similarly to an industrial scale column. The improvements include an integrated automation system with Internet communication for self-management of the plant with remote monitoring and autonomous operation.