Fluidized bed reactor

• US 4,003,712 A
• Filed: 03/14/1975
• Issued: 01/18/1977
• Est. Priority Date: 07/29/1970
• Status: Expired due to Term

• Current Assignee: Union Carbide Corporation (Dow, Inc.)
• Original Assignee: Union Carbide Corporation (Dow, Inc.)
• Inventors: Miller, Adam R.
• Primary Examiner(s): Scovronek, Joseph
• Application Number:
  US05/558,435
• Time in Patent Office: 676 Days
• Field of Search: 23/288 S, 23/288 E, 23/283, 260/94.9 P, 260/695, 526/59, 526/68, 526/88, 526/901
• US Class Current: 422/62
• CPC Class Codes: B01J 2208/00256 in a heat exchanger for the heat exchange medium separate from the reactor
• CPC Class Codes: B01J 2208/00274 involving reactant vapours
• CPC Class Codes: B01J 2208/00628 Controlling the composition of the reactive mixture
• CPC Class Codes: B01J 2208/00761 Discharging
• CPC Class Codes: B01J 8/0035 Periodical feeding or evacuation
• CPC Class Codes: B01J 8/1809 Controlling processes
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 10/02 Ethene
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 2/34 Polymerisation in gaseous state
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/07 High density, i.e. > 0.95 g/cm3
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 4/69 Chromium, molybdenum, tungsten or compounds thereof
• CPC Class Codes: C08F 4/78 selected from chromium, molybdenum or tungsten
• CPC Class Codes: Y10S 526/901 Monomer polymerized in vapor state in presence of transition metal containing catalyst

Abstract

A fluid bed reactor system and process employing a silyl chromate catalyst therein wherein the reactor system comprises a vertical reactor having a fluidizing medium permeable distribution plate towards the base thereof, a fluidizing medium supply line to supply fluidizing medium to the base of the reactor, a catalyst injection means to supply particulate catalyst to the side of the reactor, a polymer product recovery means to recover polymer product from the reactor and beneath the distribution plate, a fluidizing medium recycle line to recycle the fluidizing medium from and to the reactor, and a heat exchanger in the recycle line to remove heat of reaction from the recycled fluidizing medium.

Claims

1. A fluid bed reactor system in which olefin monomers may be catalytically polymerized continuously in a fluid bed under gas medium fluidized conditions, and comprising

a vertical reactor having a cylindrical lower section and an upper section have a cross section greater than that of said lower section, said lower section being adapted to house a polymerization zone in which the catalyzed polymerization reaction may be conducted under gas medium fluidized fluid bed conditions, and said upper section being adapted to function as a velocity reduction zone for the recovery of particles entrained in fluidizing medium entering said upper section from said lower section, fluidizing medium permeable distribution plate means within and towards the base of said lower section, said distribution plate means being adapted to diffuse fluidizing medium up through the fluidized bed in said lower section and to support said bed thereon when said bed is quiescent,

fluidizing medium supply line means in gas communication with, and adapted to supply fluidizing medium and make up gas to, the lower section of said reactor and below said distribution plate means,

catalyst injection means in catalyst supply communication with, and adapted to supply particulate olefin polymerization catalyst to, the side of the fluidized bed in the polymerization zone in said lower section,

polymer product recovery means in polymer product recovery communication with, and adapted to recover polymer product from, the base of said polymerization zone and above said distribution plate means,

said polymer product recovery means comprising a valved chamber which is adapted to recover polymer product from said reactor at a rate equal to the rate of polymer product formation with the aid of a pressure differential between the pressure within said reactor and the pressure within said chamber,

fluidizing medium recycle line means in gas communication with said reactor and adapted to recover fluidizing medium from the upper section of said reactor and to recycle the thus recovered fluidizing medium to the lower section of said reactor at a point below said distribution plate means,

heat exchange means within said recycle line means adapted to remove heat of reaction from the recycled fluidizing medium,

gas analyzer means in gas communication with said velocity reduction zone and adapted to analyze gas component deficiency in the fluidizing medium in sad velocity reduction zone, and

said fluidizing medium supply line means being in gas communication with said recycle line means and in gas supply activating response communication with said gas analyzer means and adapted to supply deficient components of the fluidizable medium to said recycle line means in response to gas supply activating communication from said gas analyzer means.

2. A fluid bed reactor system as in claim 1 in which said vertical reactor is adapted to accommodate a minimum mass gas flow rate through a fluidized bed therein in the range of 2 to about 6 G_mf.

3. A fluid bed reactor system as in claim 2 in which said lower section of said reactor has a diameter to height ratio of about 1:

6 to 1;

7.5 and said upper section of said reactor has a diameter to height ratio of about 1;

1 to 1;

2.

4. A fluid bed reactor system as in claim 1 in which said vertical reactor is adapted to operate under a pressure in the range of 40 to 300 psi.

5. A fluid bed reactor system as in claim 1 in which said catalyst injection means is adapted to supply the catalyst to the polymerization zone at a point which is abut 1/4 to 3/4 of the height of the fluidized bed in said polymerization zone.

6. A fluid bed reactor system as in claim 5 in which said catalyst injection means is adapted to supply catalyst to the polymerization zone at a rate equal to the rate of catalyst consumption.

7. A fluid bed reactor system as in claim 1 in which said fluidizing medium supply line means and said fluidizing medium recycle line means are adapted to use common gas communication line means at their point of gas communication with the lower section of said reactor.