Proposed is a process for producing methanol from synthesis gas by means of multi-stage, for example two-stage, heterogeneously catalyzed methanol synthesis, wherein the methanol product formed in every synthesis stage is separated by condensation and the remaining residual gas is supplied to the downstream synthesis stage or after separation of a purge stream recycled to the first synthesis stage as a recycle stream. According to the invention after each synthesis stage the residual gas streams have separated from them a respective purge stream, from which, using one or more hydrogen recovery apparatuses, hydrogen is separated and recycled to the first synthesis stage. The ratio of the individual purge streams and their total molar flow may optionally be varied to allow better control of the reaction in the individual synthesis stages and to allow reaction to the advancing deactivation of the catalysts present therein.

A process includes periodically or continuously introducing an olefin monomer and periodically or continuously introducing a catalyst system or catalyst system components into a reaction mixture within a reaction system, oligomerizing the olefin monomer within the reaction mixture to form an oligomer product, and periodically or continuously discharging a reaction system effluent comprising the oligomer product from the reaction system. The reaction system includes a total reaction mixture volume and a heat exchanged portion of the reaction system comprising a heat exchanged reaction mixture volume and a total heat exchanged surface area providing indirect contact between the reaction mixture and a heat exchange medium. A ratio of the total heat exchanged surface area to the total reaction mixture volume within the reaction system is in a range from 0.75 in.sup.−1 to 5 in.sup.−1, and an oligomer product discharge rate from the reaction system is between 1.0 (lb)(hr.sup.−1)(gal.sup.−1) to 6.0 (lb)(hr.sup.−1)(gal.sup.−1).

An ethylbenzene dehydrogenation plant for producing styrene which comprises a reaction section in which one or more adiabatic reaction apparatuses are positioned in series, and a steam circuit in which there is at least one first steam heat exchange apparatus; said plant being characterized in that it comprises heating equipment in which there is a heating circuit by means of recirculation of the fumes formed during dehydrogenation processes of ethylbenzene to give styrene, wherein said heating equipment comprises the following apparatuses in fluid communication with each other by means of said heating circuit: one or more ultra-heating apparatuses, one or more combustion devices in which at least one steam diffuser, one burner and at least one mixing apparatus are inserted, one or more ventilation device(s).

Proposed is a process for producing methanol from synthesis gas by means of multi-stage, for example two-stage, heterogeneously catalyzed methanol synthesis, wherein the methanol product formed in every synthesis stage is separated by condensation and the remaining residual gas is supplied to the downstream synthesis stage or after separation of a purge stream recycled to the first synthesis stage as a recycle stream. According to the invention after each synthesis stage the residual gas streams have separated from them a respective purge stream, from which, using one or more hydrogen recovery apparatuses, hydrogen is separated and recycled to the first synthesis stage. The ratio of the individual purge streams and their total molar flow may optionally be varied to allow better control of the reaction in the individual synthesis stages and to allow reaction to the advancing deactivation of the catalysts present therein.

A process for polymerizing olefin monomer(s) in a gas-solids olefin polymerization reactor comprising a top zone; a middle zone, which comprises a top end in direct contact with said top zone and which is located below said top zone, the middle zone having a generally cylindrical shape; and a bottom zone, which is in direct contact with a bottom end of the middle zone and which is located below the middle zone; comprising the following steps: introducing a fluidization gas stream into the bottom zone; polymerizing olefin monomer(s) in the presence of a polymerization catalyst in a dense phase formed by particles of a polymer of the olefin monomer(s) suspended in an upwards flowing stream of the fluidization gas in the middle zone; introducing a jet gas stream through one or more jet gas feeding ports in a jet gas feeding area of the middle zone at the dense phase in the middle zone of the gas-solids olefin polymerization reactor; wherein the kinetic energy (E.sub.JG) input in the reactor by the jet stream is between 1.5 and 50 times higher than the kinetic energy (E.sub.FG) input in the reactor by the fluidization gas stream (FG).

A hydrogen bromide (HBr) oxidation/quench system includes a heat exchanger reactor and an adiabatic catalytic reactor in fluid communication with the heat exchanger reactor. The system also includes a quench vessel, the quench vessel in fluid communication with the adiabatic catalytic reactor. The quench vessel has a flange. In addition, the system includes a joined three phase separator and absorber column, wherein both the three phase separator and the absorber column are in fluid communication with the quench vessel and an aqueous stripping column in fluid communication the heat exchanger reactor and the absorber column.

A method for producing burnt end products from an educt (starting raw materials) of carbonate-containing materials involves preheating the educt using heat recovered from the reaction. The educt and a fluidizing medium including steam are input into a first reaction zone. Heat is transferred to the first reaction zone using mechanical components so as to heat the first reaction zone to a predetermined temperature range for a predetermined time period. The educt is burned in the first reaction zone over the predetermined time period during which the first reaction zone is maintained within the predetermined temperature range. The hot gases that form in the first reaction zone include CO.sub.2 and steam. Hot end product is discharged from the first reaction zone after the predetermined time period elapses. Heat contained in the hot gases and end product that are discharged from the first reaction zone is used to preheat the educt.

A process includes periodically or continuously introducing an olefin monomer and periodically or continuously introducing a catalyst system or catalyst system components into a reaction mixture within a reaction system, oligomerizing the olefin monomer within the reaction mixture to form an oligomer product, and periodically or continuously discharging a reaction system effluent comprising the oligomer product from the reaction system. The reaction system includes a total reaction mixture volume and a heat exchanged portion of the reaction system comprising a heat exchanged reaction mixture volume and a total heat exchanged surface area providing indirect contact between the reaction mixture and a heat exchange medium. A ratio of the total heat exchanged surface area to the total reaction mixture volume within the reaction system is in a range from 0.75 in.sup.−1 to 5 in.sup.−1, and an oligomer product discharge rate from the reaction system is between 1.0 (lb)(hr.sup.−1)(gal.sup.−1) to 6.0 (lb)(hr.sup.−1)(gal.sup.−1).

A process includes periodically or continuously introducing an olefin monomer and periodically or continuously introducing a catalyst system or catalyst system components into a reaction mixture within a reaction system, oligomerizing the olefin monomer within the reaction mixture to form an oligomer product, and periodically or continuously discharging a reaction system effluent comprising the oligomer product from the reaction system. The reaction system includes a total reaction mixture volume and a heat exchanged portion of the reaction system comprising a heat exchanged reaction mixture volume and a total heat exchanged surface area providing indirect contact between the reaction mixture and a heat exchange medium. A ratio of the total heat exchanged surface area to the total reaction mixture volume within the reaction system is in a range from 0.75 in.sup.1 to 5 in.sup.1, and an oligomer product discharge rate from the reaction system is between 1.0 (lb)(hr.sup.1)(gal.sup.1) to 6.0 (lb)(hr.sup.1)(gal.sup.1).

The disclosure pertains to a high pressure carbamate condensation apparatus for a urea plant, a urea plant, and a urea production method. The apparatus comprises a first U-shaped tube bundle arranged around a second U-shaped tube bundle.