A polymerization device that includes: a reaction vessel that houses a polymerization solution and in which a polymerization reaction is performed; a stirring blade that stirs the polymerization solution housed in the reaction vessel; a plurality of heat transfer pipes that transfer heat to the polymerization solution in order to start the polymerization reaction and cause the polymerization reaction to proceed, and that remove, from the polymerization solution, heat generated by the polymerization reaction; and a baffle arranged between a vessel wall of the reaction vessel and the heat transfer pipes.

A reactor apparatus includes a reactor having a tubular shape, and a plurality of first cooling pipes arranged inside the reactor, for circulating a coolant. Each of the plurality of first cooling pipes has a serpentine portion that extends while repeatedly bending. The serpentine portion includes a plurality of extending portions that extend linearly or extend while curving, and a plurality of bending portions which couple ends of two adjacent extending portions, among the plurality of extending portions. At least two of the plurality of first cooling pipes have different distances from an inner wall surface of the reactor.

Reduced tube pitch within a shell-and-tube heat exchange reactor such as, for example, an EO reactor, is provided by utilizing a welding material that has a high tensile (i.e., a tensile strength of greater than 600 MPa). Reduced tube pitch allows for more elongated tubes (the tubes are filled with a catalyst) to be present in a reactor, and thus a smaller reactor can be manufactured. Notably, the use of a high tensile strength welding material allows the implementation of a small welding groove located between a beveled sidewall of a beveled upper portion of an opening provided in a tube sheet overlay material (that is located atop a tube sheet) and an outermost sidewall of the elongated tube passing through the opening in the tube sheet overlay material.

The invention discloses a synthesis method and device for rapidly producing lactide at high yield. The method comprises: adding a single component of lactic acid or two components of lactic acid and catalyst, passing the mixture through a mixer to enter an oligomer preparation system, increasing a residence time through bottom circulation, synthesizing oligomeric lactic acid, and passing a gas-phase component through a rectification system. With the adoption of the device, the lactide is capable of being efficiently synthesized, crude lactide with a yield of 94% to 98% is capable of being obtained.

Disclosed is a combined reformer including two or more catalyst tubes reacting at different temperatures, having different reforming reactions continuously performed as a combustion gas sequentially supplies heat to two or more catalyst tubes, and capable of easily replacing a catalyst, and a catalyst replacement method thereof.

A hybrid vertical plug flow reactor is comprised of a bottom inlet and a top outlet having vertical tubular member disposed there between, wherein the bottom inlet has separate gas reactant inlet and separate liquid reactant inlet whereby the gas reactant is mixed with the liquid reactant and the outlet has an extraction port, the extraction port extending sufficiently to withdraw the liquid product from the reactor and maintain a gaseous head space within the tubular member of the reactor. The hybrid vertical bubble plug flow reactor is useful to react a gas reactant and liquid reactant that are reacted at a molar ratio of gas reactant/liquid reactant that is in excess of a stoichiometric requirement of gas reactant so that the gas reactant forms bubbles and the reactants react in the presence of a catalyst to form a reaction product.

Method and apparatus that enable the more efficient manufacture of urea are provided. Before unreacted substances are removed from a urea synthesis solution obtained from a stripper, the urea synthesis solution is placed under pressure reduced from the synthesis pressure. Thus, a gas-liquid mixture is obtained. The gas-liquid mixture is heated with a decomposed gas from the stripper using a shell-and-tube heat exchanger, and then introduced into a purification system. In the heating, the gas-liquid mixture is introduced into the shell of the heat exchanger while the decomposed gas is introduced into the tube side of the heat exchanger.

A heat exchanger having a housing, which defines a first volume (V1), and having at least one conduit, which defines a second volume (V2), wherein the housing has an inlet and an outlet and at least one first opening and at least one second opening located opposite the first opening relative to the housing, wherein the at least one conduit extends through the first volume (V1) and connects the at least one first opening of the housing and the at least one second opening of the housing, and is connected at the two ends of the conduit to the housing in a fluid-tight manner. In order to provide a heat exchanger which has an improved possibility for compensating for the differential thermal expansion of the housing and the conduits, the at least one conduit does not extend in a linear manner inside the first volume (V1), and the at least one conduit is monolithically connected in the region of the first opening of the conduit and/or the second opening of the conduit to the housing.

An integrated reactor system for performing an ionic liquid-catalyzed hydrocarbon conversion is provided. The integrated reactor system provides intimate and rapid mixing between hydrocarbon reactants and ionic liquid catalysts while simultaneously removing reaction heat with a heat exchanger that is internal to the hydrocarbon conversion reactor.

A representative point of each of the plurality of first cooling pipes in a plane substantially perpendicular to an extending direction of the straight body is located substantially on a circumference of any of a plurality of virtual circles arranged substantially concentrically in the substantially perpendicular plane. A number Nc [units] of the plurality of virtual circles and a proportion CZ [mg-dispersing aid/kg-monomer] of a mass of the dispersing aid to a mass of one or more types of monomers to be materials of the polymer satisfy a particular relationship.