Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/49—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reaction with carbon monoxide
  • C07C45/50—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reaction with carbon monoxide by oxo-reactions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/24—Stationary reactors without moving elements inside
  • B01J19/2415—Tubular reactors
  • B01J19/2435—Loop-type reactors
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/16—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by oxo-reaction combined with reduction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00051—Controlling the temperature
  • B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
  • B01J2219/00087—Controlling the temperature by indirect heating or cooling employing heat exchange fluids with heat exchange elements outside the reactor
  • B01J2219/00094—Jackets

Definitions

• the present invention relates to an improvement to reactors intended for hydroformylation.
• the hydroformylation reaction also called Oxo synthesis, consists in reacting a synthesis gas, consisting of a mixture of carbon monoxide and hydrogen, with an olefin, liquid phase containing "n" carbon atoms, so as to obtain a mixture of aldehydes and primary alcohols containing n + 1 carbon atoms.
• the reaction is catalyzed by the carbonyls of transition metals, and in particular cobalt hydrocarbonyl or dicobalt octocarbonyl. This type of reaction is described in US Patent 3,188,351.
• the reactor usually used for this kind of continuous reaction is of the "loop" type, in which the liquid phase is put into recirculation by the principle of the gas pump.
• This reactor is composed of at least two parallel vertical tubes connected to their lower and upper parts. At least one of the vertical tubes serves as a rising branch and is continuously supplied at its base with synthesis gas and in the liquid phase while at least one vertical tube serving as a descending branch allows only the liquid phase to circulate, all of the gas synthesis and the excess liquid phase being evacuated at the upper connection.
• the reactor has at its upper part a wide flaring facilitating the separation of all of the synthesis gases from the liquid phase which must recirculate.
• FIG. 1 and 4 illustrate the reactors usually used as well as their operating principle.
• the rising branch 1 supplied by the pipe 5 with a mixture of synthesis gases and in the liquid phase, the reagents which separate in the flare 4 circulate, all of the synthesis gases and the excess of the liquid phase being removed by the tube 6, while the liquid phase 7 free of synthesis gas circulates in the descending branch 2.
• the vertical tubes are provided with cooling means 3.
• the reactor according to the invention is a “loop” type reactor made up of at least two parallel vertical tubes connected in a known manner to their lower part. At least one of the tubes supplied at its base with synthesis gas and in the liquid phase serves as a rising branch and at least one of the tubes serves as a descending branch.
• the vertical tubes are connected to each other at their upper part by a tubular loop whose internal diameter, for an internal diameter "d" of the rising branch, can be between and 2d and preferably between 0.8d and 1.2d.
• any connection going from the connection constituted by two bends at 90 ° C to the bent tubing in half-torus the bending radius measured at the axis of the elbow being preferably between 1.5d and 5d and so usual between 2d and 3d.
• the discharge orifice On the tubular loop is the discharge orifice, preferably substantially in the vertical axis of the reactor.
• This orifice for evacuation of the synthesis gases and of the excess liquid phase is of a diameter, by reference the diameter "d" of the rising branch, usually less than and greater than and preferably between 1 and
• the evacuation orifice can be, practically, constituted by an extraction tube, having an internal diameter as defined above, fixed on the tubular loop.
• Figures 5 to 11 illustrate, without limitation, different types of reactors according to the invention.
• 1 and 2 respectively represent the rising and falling branches, 3 cooling means, 4 the upper tubular connection loop, 5 the supply pipe for synthesis gas and in the liquid phase, 6 the extraction pipe .
• Figures 6 and 10 show an alternative embodiment according to which the extraction of synthesis gases and of the excess liquid phase takes place through an evacuation orifice 7 placed as close as possible to the line of tangency of the tubular loop.
• the discharge orifice 7 has an internal diameter, with reference to the diameter "d" previously mentioned, generally less than and greater to and preferably between and; Consequently, the diameter of the tubing 6 can be arbitrary provided that it is greater than or equal to that of the discharge orifice 7.
• the extraction pipes are fixed to the tubular loop by any known means, such as for example by welding or by leaktight connection.
• the absence of metal deposits in the descending branch the increased productivity, the speed of recirculation of the liquid phase comparable to that obtained in conventional reactors, quality of the liquid recirculation.
• the entrainment of synthesis gas in the descending branch ensures perfect stability of the carbonyls of metals used as catalyst.
• the metallic deposits on the walls of the descending branch hardly exist any more. Thanks to the improvement which is the subject of the invention, the duration of the cycles between two cleanings of the reactor is from 24 to 36 months instead of 1 to 3 months for an equivalent reactor according to the prior art.
• synthesis gas is present in the descending branch makes it possible to improve the productivity of the reactors by up to approximately 20%, all other things being equal to technological improvement.
• the synthesis gas is no longer in sufficient quantity which causes, in addition to the decomposition of the catalyst, the stopping of the reaction for lack of reagent.
• the entrainment of synthesis gas in the descending branch there is always enough reagent to allow the hydroformylation reaction to continue.
• the entrainment of synthesis gas in the descending branch practically does not alter the rate of recirculation of the liquid.
• the recirculation rates of the liquid were measured using a radioactive tracer.
• the liquid recirculation rates are, under industrial operating conditions, between 1.0 and 1.6 m / second depending on the flow rate of synthesis gas.
• the same reactor modified in its upper part according to FIG.
• the recirculation speeds of the liquid are in the same industrial operating conditions between 1.0 and 1.5 m / second. This maintenance of high recirculation speed also facilitates mixing between the synthesis gas and the liquid phase.
• the quality of the recirculation in the improved reactors can be controlled by the absence of significant temperature differences between two points of the reactor and measurable differences in concentration of the liquid phase inside the reactor.
• the total flow rate of synthesis gas supplied to the first reactor is 2,750 Nm 3 / h including 350 Nm 3 / h are recycled and 2,400 Nm 3 / h comes from new gas.
• the flow rate of gas consumed by the reaction represents approximately 1,900 Nm 3 / h.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)

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Citations (4)

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• 1978
  • 1978-07-13 FR FR7820970A patent/FR2430794A1/fr active Granted
• 1979
  • 1979-06-14 IN IN432/DEL/79A patent/IN152384B/en unknown
  • 1979-07-02 BE BE0/196065A patent/BE877400A/fr not_active IP Right Cessation
  • 1979-07-10 IT IT68436/79A patent/IT1120989B/it active
  • 1979-07-11 DE DE19792927979 patent/DE2927979A1/de active Granted
  • 1979-07-12 JP JP8752779A patent/JPS5513295A/ja active Granted
  • 1979-07-12 CA CA331,663A patent/CA1115498A/fr not_active Expired
  • 1979-07-12 NL NL7905459A patent/NL191761C/xx not_active IP Right Cessation
  • 1979-07-13 WO PCT/FR1979/000065 patent/WO1982003624A1/fr not_active Ceased
• 1980
  • 1980-03-13 US US06/196,489 patent/US4312837A/en not_active Expired - Lifetime

Patent Citations (4)

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