Scavenging chemicals used in mitigation treatments of hydrogen sulfide in hydrocarbon streams often continue to react and form polymers that foul the processing system. Disclosed herein are methods for determining if a scavenging chemical mitigator, or its reaction or degradation product, will polymerized during or after mitigation treatments. This information allows for the optimization of mitigation treatments that pre-emptively control or prevent polymer formation. Such pre-emption measures reduce the cost and time related to remedial actions to treat polymer-fouled equipment.

The present invention relates to a method for preparing ethylene vinylacetate copolymer that can improve the mechanical strength of copolymer by controlling the polymerization conditions using an autoclave reactor.

A method of forming a compound having the formula:

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includes the reaction:

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n the presence of a base comprising teat-butyl lithium, lithium diisopropylamide, sodium hydroxide, potassium hydroxide, lithium hydroxide, a potassium alkoxide or a sodium alkoxide to achieve a yield of at least 90%, wherein X is a halo atom selected from the group consisting of Cl, Br and I.

Devices and methods for determining the cumulative distribution of a polymer property in a reactor without physical separation of reaction subcomponents. The device includes a means of measuring an instantaneous property of the polymers being produced in a reaction vessel a plurality of times during a polymerization reaction as well as a means of determining the corresponding change in polymer concentration in the reaction vessel between measurements of the instantaneous polymer property The device also includes a means of computing a statistical distribution appropriate to the polymer characteristic and applying the statistical distribution to a recently measured instantaneous value of the polymer property so as to have an instantaneous distribution of the polymer property and a means of adding together the instantaneous distributions of the polymer property in order to obtain the cumulative distribution of the polymer property in the reactor.

A variation in the performance value of a polymer being manufactured can be reduced. A prediction device (10A) that, in manufacturing of a polymer, predicts a performance value indicating performance of the polymer in a polymerization tank after a raw material is fed, and may include: an acquisition unit (111) that acquires, as a prediction observation value, an observation value observed, in current manufacturing of the polymer, as a value related to the manufacturing of the polymer; and a prediction unit (112) that predicts the performance value of the polymer being currently manufactured at a predetermined timing, from the prediction observation value acquired by the acquisition unit, by using a relation between an observation value acquired in past manufacturing of the same type of polymer as the polymer, and a performance value of the polymer at the predetermined timing in the past manufacturing.

Methods for operating a high pressure olefin polymerization reactor include the steps of introducing an initiator stream containing ethylene and an initiator compound through an initiator nozzle into the reactor, introducing an olefin stream containing ethylene and an optional comonomer through an olefin nozzle into the reactor, and polymerizing ethylene and optionally the comonomer in the presence of the initiator stream in the reactor under high pressure polymerization conditions to produce an ethylene polymer. The amount of ethylene in the initiator stream is from 0.01 to 2 wt. % of the amount of ethylene in the olefin stream. An injection nozzle that can be used in conjunction with the high pressure reactor also is described.

Methods for operating a high pressure olefin polymerization reactor include the steps of introducing an initiator stream containing ethylene and an initiator compound through an initiator nozzle into the reactor, introducing an olefin stream containing ethylene and an optional comonomer through an olefin nozzle into the reactor, and polymerizing ethylene and optionally the comonomer in the presence of the initiator stream in the reactor under high pressure polymerization conditions to produce an ethylene polymer. The amount of ethylene in the initiator stream is from 0.01 to 2 wt. % of the amount of ethylene in the olefin stream. An injection nozzle that can be used in conjunction with the high pressure reactor also is described.

A process or apparatus for producing polyethylene with improved film thinning and handleability involves polymerizing high-pressure ethylene using an autoclave-type reactor in the presence of a polymerization initiator. The reaction zone of the reactor has at least two different temperature sections; the polymerization initiator and the ethylene are supplied to the upstream temperature section in the reaction zone and the ethylene is polymerized to generate polyethylene; unreacted ethylene and the polyethylene generated at the upstream temperature section in the reactor flow into the downstream temperature section in communication with the upstream temperature section, so that additional polyethylene is generated at the downstream temperature section. A difference (ΔT [° C.]) between a temperature (T1 [° C.]) of the temperature section positioned upstream and a temperature (T2 [° C.]) of the temperature section positioned downstream in the reaction zone that receives the polymerization initiator and is in the autoclave-type reactor is 2.1° C. to 8.4° C.

Devices and methods for determining the cumulative distribution of a polymer property in a reactor without physical separation of reaction subcomponents. The device includes a means of measuring an instantaneous property of the polymers being produced in a reaction vessel a plurality of times during a polymerization reaction as well as a means of determining the corresponding change in polymer concentration in the reaction vessel between measurements of the instantaneous polymer property. The device also includes a means of computing a statistical distribution appropriate to the polymer characteristic and applying the statistical distribution to a recently measured instantaneous value of the polymer property so as to have an instantaneous distribution of the polymer property and a means of adding together the instantaneous distributions of the polymer property in order to obtain the cumulative distribution of the polymer property in the reactor.

Scavenging chemicals used in mitigation treatments of hydrogen sulfide in hydrocarbon streams often continue to react and form polymers that foul the processing system. Disclosed herein are methods for determining if a scavenging chemical mitigator, or its reaction or degradation product, will polymerized during or after mitigation treatments. This information allows for the optimization of mitigation treatments that pre-emptively control or prevent polymer formation. Such pre-emption measures reduce the cost and time related to remedial actions to treat polymer-fouled equipment.