JP2008081536A - Emergency stop system of polymerization reaction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emergency stop system of polymerization reaction, having an excellent characteristic that a polymerization reaction is surely and rapidly stopped urgently by relatively simple equipment. <P>SOLUTION: The emergency stop system of polymerization reaction has (A) piping that is piping supplying a polymerization deactivator to a polymerizion tank and having at least one on-off valve in the middle of it and (B) piping that is piping branched from the piping (A), connected to purge equipment and having an on-off valve and an orifice for flow rate control in the middle of it. A (co)polymerization of an olefin such as ethylene, propylene, etc., may be cited as the example of the objective polymerization reaction and, in more concrete, a vapor-phase polymerization reaction of an olefin may be cited. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an emergency stop system for a polymerization reaction. More specifically, the present invention relates to an emergency stop system for a polymerization reaction having an excellent feature that the polymerization reaction can be stopped quickly and reliably with relatively simple equipment.

  Polyethylene, polypropylene and the like are obtained by subjecting monomers such as ethylene and propylene to a polymerization reaction. By the way, when an abnormality occurs in the polymerization reaction system, it is necessary to urgently stop the polymerization reaction. This is because the temperature and pressure rise abnormally due to the abnormal reaction, and there is a problem that the equipment is destroyed and dangerous, and the monomer is wasted. By the way, as an emergency stop method for the polymerization reaction, a method in which a polymerization deactivator is directly introduced into the polymerization reaction tank is known (for example, see Patent Document 1).

  However, the conventional methods are not always satisfactory from the viewpoint that the polymerization reaction can be stopped urgently reliably and quickly with relatively simple equipment.

JP-A-9-95504

  In such a situation, the problem to be solved by the present invention is to provide an emergency stop system for a polymerization reaction having an excellent feature that the polymerization reaction can be stopped quickly and reliably with relatively simple equipment. It is in.

That is, the present invention relates to an emergency stop system for a polymerization reaction having the following facilities (A) and (B).
(A): Pipe for supplying a polymerization deactivator to the polymerization tank and having at least one on-off valve in the middle thereof (B): Pipe branched from the pipe of (A) and connected to the purge facility A pipe having an on-off valve and an orifice for restricting the flow rate in the middle

  According to the present invention, it is possible to provide an emergency stop system for a polymerization reaction having an excellent feature that the polymerization reaction can be stopped quickly and reliably with relatively simple equipment.

  Examples of the polymerization reaction targeted by the present invention include olefin (co) polymerization reactions such as ethylene and propylene, and more specifically, gas phase polymerization reactions of olefins.

  Specific examples of the polymerization quencher used in the present invention include carbon monoxide.

  As an example of the case where an emergency stop of the polymerization reaction is required, there can be mentioned a case where the temperature or pressure of the reaction system has abnormally increased due to an abnormal reaction. In such a case, it is necessary to stop the polymerization reaction promptly and reliably from the viewpoints of ensuring safety and protecting the equipment.

  The present invention will be described below in comparison with a conventional example.

  FIG. 1 shows an example of the present invention, which is a pipe for supplying a polymerization deactivator to a polymerization tank, having a pipe having at least one on-off valve in the middle thereof, branched from the pipe and connected to a purge facility. A piping having a switching valve and an orifice for restricting the flow rate is provided in the middle of the piping.

  On the other hand, FIG. 2 shows a conventional example.

  In the conventional example, when an emergency stop is performed, a polymerization deactivator charging operation to the polymerization tank is started by a charging sequence operation based on establishment of a polymerization deactivating agent charging condition or a manual charging button. In the charging operation, the internal purge remote valve 6 is switched from open to closed, and after the closing signal is confirmed by the valve 6 closing signal, the polymerization quencher remote charging valves 2 and 3 are opened from closed to open. A polymerization quencher is put into the polymerization tank to stop the polymerization reaction. In this case, in the case of an abnormality such as a poor closing of the valve 6, the valves 2 and 3 remain in the closed state because the valve 6 closing signal is set under the condition for switching the valves 2 and 3 from closing to opening. Thus, there is a problem that the polymerization deactivator is not charged into the polymerization tank.

  On the other hand, in the case of performing an emergency stop in the present invention, the valve 6 is switched from open to closed without changing to the polymerization deactivator charging operation as in the prior art, and the valves 2 and 3 are closed to open so that the polymerization deactivator enters the polymerization tank. In this case, an orifice is provided in the purge pipe to restrict the flow rate, so that the valves 2 and 3 are switched from closed to open regardless of whether the valve 6 is closed. Rapid polymerization deactivator charging is possible and does not involve the above problems. In the present invention, a combustion facility can be used as a purge facility for the gas to be purged outside the system during an emergency stop.

Next, the present invention will be described with reference to examples.
Example 1
The polymerization deactivator charging operation to the polymerization tank is started by the charging sequence operation or the manual charging button when the polymerization deactivator charging condition is established, and the internal purge remote valve 6 is switched from open to closed, and the polymerization deactivation is performed. The agent remote charging valves 2 and 3 are opened from the closed state, and a polymerization deactivator is charged into the polymerization tank to stop the polymerization reaction.

2 is an example of a system according to the present invention. It is an example of the conventional system.

Explanation of symbols

1: Polymerization tank 2, 3: Deactivator charging remote valve 4: Polymerization deactivator 5: Orifice 6: Remote valve for internal purge of valve 3: Purging equipment 8: Safety valve 9: Safety valve bypass valve

Claims (6)

An emergency stop system for polymerization reaction having the following facilities (A) and (B).
(A): Pipe for supplying a polymerization deactivator to the polymerization tank and having at least one on-off valve in the middle thereof (B): Pipe branched from the pipe of (A) and connected to the purge facility A pipe having an on-off valve and an orifice for restricting the flow rate in the middle The system according to claim 1, wherein the polymerization reaction is an olefin polymerization reaction. The system according to claim 1, wherein the polymerization reaction is a gas phase polymerization reaction of olefin. 2. The system according to claim 1, wherein the polymerization reaction is a (co) polymerization reaction of ethylene and / or propylene. The system of claim 1 wherein the polymerization quencher is carbon monoxide. The system of claim 1, wherein the purge facility is a combustion facility.

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