A method of producing particles by bringing plural dissimilar materials A and B into contact with each other includes feeding a liquid into a reactor from a first end portion of the reactor such that the liquid flows along the inner peripheral surface of the reactor and generating a vortex flow toward a second end portion in the reactor by the feed of the liquid; disposing a flow-assisting blade capable of rotating around the central axis line in the reactor and rotating the flow-assisting blade; and injecting materials to be contacted A and B into the reactor, discharging a contacted liquid from the second end portion of the reactor, and generating the particles in the contacted liquid.

A fermenter and a method of fermentation in a U-shape and/or nozzle U-loop fermenter (100) comprising a U-part having an essentially vertical down-flow part (101), an essentially vertical up-flow part (102) and a substantially horizontal connecting part (103), which connects the lower ends of the down-flow part (101) and the up-flow part (102), a top part (104) which is provided above the U-part and has a diameter which is substantially larger than the diameter of the U-part, means for creating liquid circulation in U-part of the fermenter, and one or more gas injection points (110) for the introduction and dispersion of the gas(ses) into the fermentation liquid. The pressure may be controlled differently in certain zones of the fermenter by pressure controlling devices (105, 106, 108) e.g. by increasing the pressure in certain zones of the fermenter in relation to the pressure in the other zones of the fermenter, or decreasing the pressure in a zone of the fermenter in relation to the pressure in another zone of the fermenter in relation to the pressure in another zone of the fermenter.

Disclosed is a urea plant wherein, in deviation from conventional plants, a high-pressure synthesis section is operated with two different pressures. The synthesis section comprises a reactor, which is operated under a first high pressure. The synthesis section also comprises a stripper and a condenser, both operated at substantially the same second high pressure. In accordance with the invention, the first pressure is substantially higher than the second pressure. The disclosed plant particularly comprises a compression unit capable of converting a pressure difference into work, or more specifically, mechanical energy for compression. This compression unit is positioned between a liquid outlet of the condenser and a liquid inlet of the reactor, and in fluid communication therewith. In order to make use of a pressure drop (expansion as a result of a liquid being depressurized), said compression unit is configured to obtain compression energy from one or more events in the urea production process (i.e., at one or more points in the urea production plant), at which a loss of energy occurs, such as decompression of a high energy stream. Typically, the compression unit is thereby configured to utilize mechanical energy recovered from a decompression unit positioned downstream of the stripper and upstream of the recovery section.

A rotary feeder comprising a stationary, cylindrical housing having disposed therein a number of injection nozzles, and within which rotate a plurality of vanes about a central axis, wherein the housing extends a width along the central axis, wherein each of the vanes has a length along the central axis, and wherein the injection nozzles are positioned across the width of the housing, such that a spray pattern of a gas injected via the number of injection nozzles spans substantially the entire length of the vanes. A system comprising and a method utilizing such a rotary feeder are also provided herein.

A process for polymerising alpha-olefin monomers in a loop reactor comprising the steps of introducing a main feed stream (2) comprising at least one alpha-olefin monomer into the loop reactor (1); introducing a polymerisation catalyst into the loop reactor (1); polymerising the at least one alpha-olefin monomer in the presence of the polymerisation catalyst in the loop reactor (1) to produce a slurry comprising polyolefin particles; withdrawing an outlet stream (4) comprising at least a portion of the slurry from the loop reactor (1); adding a first feed stream (9) comprising the at least one alpha-olefin monomer and/or hydrogen to the outlet stream (4) to form a concentrator inlet stream (8); introducing the concentrator inlet stream (8) into a concentrator (5); withdrawing from the concentrator (5) an overflow stream (6) comprising the polyolefin particles, wherein the concentration of the polyolefin particles in the overflow stream (6) is smaller than in the concentrator inlet stream (8); withdrawing from the concentrator (5) a bottom outlet stream (12) comprising the polyolefin particles, wherein the concentration of the polyolefin particles in the bottom outlet stream (12) is greater than in the concentrator inlet stream (8); returning the overflow stream (6) into the loop reactor (1) in an area different from that from which the outlet stream (4) is withdrawn.

A system and method for a first reactor to produce a transfer slurry having a first polyolefin polymerized in the first reactor, a heat-removal zone to remove heat from the transfer slurry, and a second reactor to receive the transfer slurry cooled by the heat-removal zone, the second reactor to produce a product slurry having a product polyolefin which includes the first polyolefin and a second polyolefin polymerized in the second reactor.

A system and method for startup of a polyolefin reactor temperature control system having a first reactor temperature control path, a second reactor temperature control path, and a shared temperature control path. In some embodiments, during startup the second reactor temperature control path is configured to allow the temperature of a second reactor to rise due to the heat of the exothermic polymerization reaction occurring within the reactor until reaching a predetermined setpoint temperature. In other embodiments, during startup a first reactor temperature control path is configured to include a heat exchanger used as a cooler, and a second reactor temperature control path is configured to include a heat exchanger used as a heater, to raise the temperature of the second reactor until reaching a predetermined setpoint temperature.

The present invention relates to a tubular reactor (14) for multi-phase polymerization, in particular for producing butyl rubber, comprising a pipe piece (16) for radially delimiting a reactor volume between an inlet (18) and an outlet (20), a stirrer (22) for generating a flow (27) in the radial direction of the pipe piece (16), wherein the stirrer (22) is dimensioned and operable such that the flow (27) is impartable with a centrifugal force which generates a concentration distribution in the radial direction inside the pipe piece (16) and an outlet conduit (32) for discharging a concentrated radially inner part (30) of the flow (27, 28). Enrichment of polymer particles in the radially inner part (30) of the flow (27, 28) avoids gumming of the pipe piece (16) by the polymer particles so that the risk of a blockage is reduced.

A gas phase polymerization assembly comprising a gas phase polymerization reactor having at least one inlet and at least one outlet, a circulation gas compression unit having an inlet and an outlet, whereby the inlet of the circulation gas compression unit is fluidly connected to the at least one outlet of the gas phase polymerization reactor by an unreacted gas line; a flush gas compression unit having an inlet and an outlet, wherein the inlet of the flush gas compression unit is fluidly connected to the outlet of the circulation gas compression unit by a pressurized unreacted gas line; a circulation line fluidly connecting the pressurized unreacted gas line with the at least one inlet of the gas phase polymerization reactor; a flush gas withdrawal line connected to the outlet of the flush gas compression unit.

The present embodiments provide a system and method for separation within a polymer production process. Specifically, a flashline heater configured according to present embodiments may provide more time than is required for complete vaporization of liquid hydrocarbons that are not entrained within a polymer fluff produced within a polymerization reactor. Such extra time may allow for liquid hydrocarbons that are entrained within the polymer fluff to be vaporized.