Abstract: Polymerization process for the polymerization of monomer in a polymerization system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerization system. Initially, the component is flushed with a first flush medium, and subsequently the component is flushed with a second flush medium.

Abstract: The present invention relates to vapour-solids separations, and in particular provides a process for the separation of a stream comprising vapour and a stream comprising solids from a stream comprising vapour and solids using a separation vessel, said separation vessel having: a. a first inlet for the stream to be separated, b. a liquid outlet, c. a vapour outlet, d. a demister located on the vapour outlet, and e.

Abstract: Petrochemical complex containing an olefin monomer polymerization plant having at least one polymerization reactor and an optional degassing section. The polymerization reactor contains process hydrocarbons consisting of the monomer, the optional comonomer(s) and optionally at least one inert hydrocarbon diluent, together with aluminum containing compound(s). The polymerization plant includes liquid purge stream(s) which contain aluminum containing compounds and optionally polymer fines, together with accumulated hydrocarbons which are different from the process hydrocarbons and which are hydrocarbons containing at least 4 carbon atoms. The petrochemical complex also contains a multipurpose hydrocarbon treatment unit which separates the liquid purge stream(s) into one stream having substantially all of the aluminum containing compounds and optional polymer fines, and one stream containing the accumulated hydrocarbons.

Abstract: Process for the gas-phase polymerization of olefins in a fluidized bed reactor, by a) passing a fluidizing gas containing an olefin monomer through a fluidized bed of polymer particles in the presence of a polymerization catalyst, b) withdrawing a first gaseous stream containing solid particles from the reactor, c) passing the first gaseous stream to a gas/solids separator, separating solid particles, and forming a second gaseous stream containing residual solid particles, d) passing a portion of the second gaseous stream to a heat exchanger(s) to remove heat and e) recycling a portion of the cooled stream from (d) as the fluidizing gas in (a). The fouling rate of the heat exchanger (s) is such that i) the increase in pressure drop across the heat exchanger is equivalent to less than 5%/year, and/or ii) the decrease in heat transfer of the heat exchanger is equivalent to less than 5%/year.

Abstract: Process for operating a hot particle rotary valve having a rotor and a casing. The process includes subjecting the hot particle rotary valve to an internal temperature increase treatment in which the inside of the rotary valve is heated during the start-up of the particle rotary valve.

Abstract: Polymerization process having a plurality of processing steps in which an inert gas is used or is provided as a back-up, each of the processing steps being assigned a ranking based on the requirement for an inert gas flow in the processing step. The process, in the event of a process upset, controls with a control system the supply of available inert gas based on the rankings.

Abstract: The present invention relates to a polymerisation process, and in particular provides a process for the polymeristion of monomer in a polymerisation system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerisation system, wherein initially said component is flushed with a first flush medium, and subsequently said component is flushed with a second flush medium.

Abstract: The present invention relates to a process for the gas-phase polymerisation of olefins in a fluidised bed reactor, which process comprises: a) passing a fluidising gas comprising one or more olefin monomers through a fluidised bed of polymer particles in the presence of a polymerisation catalyst, b) withdrawing a first gaseous stream comprising solid particles from the top of the reactor, c) passing the first gaseous stream to a gas/solids separator, separating solid particles therefrom, and forming a second gaseous stream comprising residual solid particles, d) passing at least a portion of the second gaseous stream to one or more heat exchangers to remove the heat of reaction, and e) recycling at least a portion of the cooled stream from step (d) as the fluidising gas in step (a), characterised in that the rate of fouling of the one or more heat exchangers is such that i) the increase in pressure drop across the heat exchangers is equivalent to less than 5% per year, and/or ii) the decrease in heat transfer

Abstract: Process for gas phase polymerization of olefins in a fluidized bed reactor by (a) passing a fluidizing gas containing at least one olefin monomer through a fluidized bed of polymer particles in the presence of a polymerization catalyst to produce polymer at a polymer production rate of C Tonnes/hour, (b) withdrawing a first gaseous stream containing solid particles from the top of the reactor, (c) passing the first gaseous stream to a gas/solids separator, separating solid particles therefrom, and forming a second gaseous stream containing residual solid particles, (d) passing a portion of the second gaseous stream to at least one heat exchanger to remove heat of reaction whereby residual solid particles contact the heat exchanger, and (e) recycling a portion of the cooled stream from step (d) as the fluidizing gas in step (a). The heat exchangers have a heat exchange surface area which totals less than 120×C m2.

Abstract: Process for the polymerization of monomer in a polymerization system having at least one component attached thereto which is flushed with a flush medium which enters the polymerization system. Initially, the component is flushed with a first flush medium, and subsequently the component is flushed with a second flush medium which differs in composition from the first flush medium. A flush gas containing monomer is used as the flush medium when the polymer production rate is above 10 Te/h.

Abstract: The present invention relates to a process for improving the operations of a polymerisation plant which uses aluminium containing compound(s).

Abstract: The present invention relates to a process for operating hot particle rotary valves during start-up.

Abstract: The present invention relates to a polymerisation process, and in particular to a polymerisation process comprising a plurality of processing steps in which an inert gas is used or is provided as a back-up, each of said processing steps being assigned a ranking based on the requirement for an inert gas flow in the processing step, said polymerisation process being characterised in that in the event of a loss of normal operating conditions the control system allocates the supply of the available inert gas based on said rankings.

Abstract: The present invention relates to a polymerisation process, and in particular provides a process for the polymerisation of monomer in a polymerisation system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerisation system, wherein initially said component is flushed with a first flush medium, and subsequently said component is flushed with a second flush medium.

Abstract: Interlock for use in a process for degassing of a polymer powder in a degassing vessel. The interlock includes the steps of 1. measuring the temperature of the polymer powder within or exiting the degassing vessel, 2. comparing the measurement value to a threshold value in order to ascertain whether it is lower than the threshold value or not, and 3. if the measured temperature is lower than the threshold value taking one or more actions to reduce the concentration of hydrocarbons in the polymer powder exiting the degassing vessel and/or to stop the polymer powder withdrawal from that degassing vessel.

Abstract: Apparatus and process for gas phase polymerisation of olefins. The apparatus includes (a) a reaction zone having a grid at its base, (b) an inlet located in the lower half of the reaction zone for introducing a reaction gas to the reaction zone, (c) an outlet located in the upper half of the reaction zone for removing the reaction gas from the reaction zone, and (d) a solids separation unit having an inlet fluidly connected to the outlet for removing the reaction gas from the reaction zone. The inlet of the solids separation unit is located at a vertical height lower than the outlet for removal of reaction gas from the reaction zone and such that the angle to the horizontal of a straight line drawn between the inlet of the solids separation unit and the outlet for removal of reaction gas from the reaction zone is greater than 20°.

Abstract: The present invention relates to an apparatus and process for the gas phase polymerisation of olefins, the apparatus comprising: a) a reaction zone comprising a grid at its base, b) an inlet located in the lower half of the reaction zone for introduction of a reaction gas to the reaction zone, c) an outlet located in the upper half of the reaction zone for removal of the reaction gas from the reaction zone, and d) a solids separation unit having an inlet fluidly connected to the outlet for removal of the reaction gas from the reaction zone, characterised in that the inlet of the solids separation unit is located at a vertical height lower than the outlet for removal of reaction gas from the reaction zone and such that the angle to the horizontal of a straight line drawn between the inlet of the solids separation unit and the outlet for removal of reaction gas from the reaction zone is greater than 20°.

Abstract: The present invention relates to a process for the gas-phase polymerisation of olefins in a fluidised bed reactor, which process comprises: a) passing a fluidising gas comprising one or more olefin monomers through a fluidised bed of polymer particles in the presence of a polymerisation catalyst, b) withdrawing a first gaseous stream comprising solid particles from the top of the reactor, c) passing the first gaseous stream to a gas/solids separator, separating solid particles therefrom, and forming a second gaseous stream comprising residual solid particles, d) passing at least a portion of the second gaseous stream to one or more heat exchangers to remove the heat of reaction, and e) recycling at least a portion of the cooled stream from step (d) as the fluidising gas in step (a), characterised in that the rate of fouling of the one or more heat exchangers is such that i) the increase in pressure drop across the heat exchangers is equivalent to less than 5% per year, and/or ii) the decrease in heat transfer

Abstract: Polymer powder vessel having a silo including a main vertical cylinder and a hopper at the bottom of the cylinder, a polymer powder which occupies the full volume of the hopper and at least a part of the volume of the cylinder, a polymer powder silo inlet pipe connected to the silo at a height located above the polymer powder, and a polymer hopper withdrawal pipe is also connected to the hopper. The polymer powder hopper withdrawal pipe is also connected to the silo at a location above the polymer powder for recirculating a part of the polymer powder within the silo.

Abstract: The present invention relates to the degassing of polymer powder, and in particular to an interlock for use in a process for degassing of a polymer powder in a degassing vessel, which interlock comprises: 1. measuring the temperature of the polymer powder within or exiting the degassing vessel, 2. comparing said measurement value to a threshold value in order to ascertain whether it is lower than the threshold value or not, and 3. if the measured temperature is lower than the threshold value taking one or more actions to reduce the concentration of hydrocarbons in the polymer powder exiting the degassing vessel and/or to stop the polymer powder withdrawal from that degassing vessel.