The present invention is directed to a polypropylene composition (C) comprising an α-nucleated heterophasic composition (HECO) comprising a (semi)crystalline polypropylene (PP1), an elastomeric ethylene/propylene copolymer (EPR) and a first α-nucleating agent (NU1), an impact modifier comprising a polyethylene (PE) being a copolymer of ethylene and a C.sub.4-C.sub.12 α-olefin and a second α-nucleating agent (NU2). The present invention is further directed to a method for preparing said polypropylene composition (C) and an article comprising said polypropylene composition (C). The present invention is also directed to the use of a composition comprising a polyethylene (PE) being a copolymer of ethylene and a C.sub.4-C.sub.12 α-olefin and an α-nucleating agent (NU2) as an impact modifier.

Systems and methods are provided for hydrogenation of CO.sub.2 in a reverse flow reactor environment via a reverse water gas shift reaction. A reverse flow reactor environment is suitable for performing endothermic reactions at high temperatures, where a reactant flow is passed into the reactor in a first portion of the cycle in a first flow direction while a combustion or heating flow is passed into the reactor during a second portion of the reaction cycle from the opposite direction. This can allow for efficient heating of surfaces within the reactor to provide heat for the endothermic reverse water gas shift reaction while reducing or minimizing incorporation of combustion products into the desired reaction products.

A process and system for maintaining optimum polymerization production in a loop polymerization reactor by continuously and periodically obtaining polymerization results, such as melt index (MI), production rate and ash content of the polymer produced, determining whether each of the results is within desired ranges, storing and averaging recently obtained results in a database within a reaction rate controller program, and when one of the results is out of the desired range modifying at least one reaction parameter set-point such as monomer concentration, catalyst feed rate and reactor temperature to drive any out-of-range polymerization result(s) toward the desired range for that result.

A process for maintaining an optimum polymerization process in a continuous loop polymerization reactor by driving a catalyst feed range set-point around a bad catalyst set-point range using a bad catalyst feed rate program to vary the catalyst feed rate for differing periods of time between previously determined good catalyst feed rates.

A supercritical water oxidation-flame piloted vortex reactor has a hydrothermal flame produced within the interior of the reactor fed by a fuel including a waste water stream, and has a subcritical wash stream, including water below its critical point, that creates an upward helical flow in the material within the reactor. The hydrothermal flame and upward helical flow produce within the reactor a supercritical core region, a subcritical outer region around the core region, and a transcritical intermediate region between them. The upward helical flow serves to transfer precipitated ionic compounds out of the supercritical core region, through the transcritical intermediate region, and into the subcritical outer region where they re-dissolve. A processed flow, including purified water, is removed from an upper portion of the supercritical core region by an aspirator.

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.

The present invention relates to multi reactor configurations for producing polypropylene copolymers and to processes for producing polypropylene copolymers. The reactor configuration for the production of propylene copolymers comprises at least three reactors R1, R1 and R3, all reactors having inlet and outlet, whereby reactors R2 and R3 are configured in parallel both downstream of reactor R1; and whereby reactor R1 is configured in series and upstream of reactors R2 and R3, and whereby the outlet of reactor R1 is coupled with the inlets of both reactors R2 and R3.

A polyolefin production system including: a first reactor configured to produce a first discharge slurry having a first polyolefin; a second reactor configured to produce a second discharge slurry having a second polyolefin; and a post-reactor treatment zone having at least a separation vessel configured to receive the second discharge slurry or both the first discharge slurry and the second discharge slurry.

A method is provided for producing at least one olefin by oxidative dehydrogenation of a hydrocarbon feed. The method includes the steps of contacting a hydrocarbon feed, which includes at least one alkane, and a steam feed with an oxygen transfer agent under a pressure of 1.1 bar to 800 bar to produce at least one olefin. The oxygen transfer agent contains a metal oxide that acts as an oxidizing agent to oxidize the at least one alkane. Additionally, the method includes the step of collecting a product stream containing the at least one olefin.