The present invention relates to a process for preparing a polyethylene product having a multimodal molecular weight distribution, said process comprising the steps of: (a) feeding ethylene monomer, a diluent, at least one metallocene catalyst, optionally hydrogen, and optionally one or more olefin co-monomers into a first slurry loop reactor; and polymerizing the ethylene monomer, and the optionally one or more olefin co-monomers, in the presence of said at least one metallocene catalyst, and optionally hydrogen, in said first slurry loop reactor thereby producing a first polyethylene fraction; (b) feeding the first polyethylene fraction to a second slurry loop reactor serially connected to the first slurry loop reactor, and in the second slurry loop reactor polymerizing ethylene, and optionally one or more olefin co-monomers, in the presence of the first polyethylene fraction, and optionally hydrogen, thereby producing a second polyethylene fraction; and (c) feeding the second polyethylene fraction to a gas phase reactor serially connected to the second slurry loop reactor, and in the gas phase reactor polymerizing ethylene, and optionally one or more olefin co-monomers, in the presence of the second polyethylene fraction, and optionally hydrogen, thereby producing the polyethylene product, wherein at least 25% by weight of the polyethylene product is prepared in the first slurry loop reactor.

A method of continuous hydrothermal carbonization of sludge containing organic matter involves a step of hydrothermal reaction carried out in a reactor, and at least one cooling step in which the sludge having undergone the hydrothermal reaction step is cooled. The hydrothermal reaction step includes: a step of injection of sludge in which the sludge is injected into the reactor by a first inlet; a step of injection of steam in which steam is injected into the reactor by a second inlet, the second inlet being distinct from the first inlet; a step of circulation, in which a mixture consisting of the sludge and the steam injected into the reactor is placed in circulation within the reactor; a step of continuous extraction of at least a portion of the mixture contained in the reactor by a sludge outlet. Also disclosed is a device for carrying out such a method.

The invention provides a process to form a composition comprising at least one ethylene-based polymer and at least one oil, said process comprising the following: polymerizing a mixture comprising ethylene, and optionally one or more comonomers, in a reactor system, comprising at least one reactor and at least one mixer, located downstream from the reactor, to form the ethylene-based polymer; and wherein the oil is added to the ethylene-based polymer upstream of the mixer. The invention also provides a reactor system for a process to form a composition comprising at least one ethylene-based polymer and at least one oil, said reactor system comprising at least one reactor, at least one mixer, and an oil feed into the ethylene-based polymer, and wherein the oil feed is located after the reactor and before the mixer.

Bromine containing compounds, such as calcium bromide, sodium bromide and the like, are prepared in high purity and more quickly with less waste by using a process with two bromination stages and often a third step wherein the crude product mixture can be adjusted to meet specific product requirements. In the first bromination stage, the majority, but not all, of a substrate is brominated using a reductive bromination reaction, the remaining unreacted substrate is converted to product in the second stage through another a reductive bromination reaction, although the specific reagents may be different, wherein the addition of bromine and a reducing agent are carefully monitored.

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 ?m, and less than 10 wt. % has a particle size less than 10 ?m, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 ?m per five grams of the ethylene polymer.

A process for producing ammonia and a derivative of ammonia from a natural gas feed comprising conversion of natural gas into a make-up synthesis gas; synthesis of ammonia; use of said ammonia to produce said derivative of ammonia, wherein a portion of the natural gas feed is used to fuel a gas turbine; power produced by said gas turbine is transferred to at least one power user of the process, such as a compressor; heat is recovered from exhaust gas of said gas turbine, and at least part of said heat is recovered as low-grade heat available at a temperature not greater than 200? C., to provide process heating to at least one thermal user of the process, such as CO.sub.2 removal unit or absorption chiller; a corresponding plant and method of modernization are also disclosed.

A process for producing ammonia and a derivative of ammonia from a natural gas feed comprising conversion of natural gas into a make-up synthesis gas; synthesis of ammonia; use of said ammonia to produce said derivative of ammonia, wherein a portion of the natural gas feed is used to fuel a gas turbine; power produced by said gas turbine is transferred to at least one power user of the process, such as a compressor; heat is recovered from exhaust gas of said gas turbine, and at least part of said heat is recovered as low-grade heat available at a temperature not greater than 200? C., to provide process heating to at least one thermal user of the process, such as CO2 removal unit or absorption chiller; a corresponding plant and method of modernization are also disclosed.

A system and method for providing dry cooling of a source liquid, having a plurality of heat exchangers which depolymerize and polymerize a polymer. Specifically, the depolymerization process is endothermic and draws heat from a source liquid in a first heat exchanger, and the polymerization process is exothermic and expels heat from a second heat exchanger. Additional heat exchangers and holding tanks may be incorporated in the system and method. In some embodiments the system further provides additional cooling of the polymer prior to depolymerization using cooler night ambient air.

Polymerization reactor systems providing integrated liquid-solid sampling systems are disclosed. Methods for operating such polymerization reactor systems and for measuring a property of the liquid portion of liquid-solid mixture are described.

A system and method for providing dry cooling of a source liquid, having a plurality of heat exchangers which depolymerize and polymerize a polymer. Specifically, the depolymerization process is endothermic and draws heat from a source liquid in a first heat exchanger, and the polymerization process is exothermic and expels heat from a second heat exchanger. Additional heat exchangers and holding tanks may be incorporated in the system and method. In some embodiments the system further provides additional cooling of the polymer prior to depolymerization using cooler night ambient air.