Polyolefin reactors

Another important factor that distinguishes this separation is that it is not environmentally or economically feasible to simply return a rejected stream to the environment, as in a typical aqueous RO process where the brine can be returned to the ocean. The federal regulations mandate that C02 emissions from refineries and chemical plants be reduced to low levels therefore, facilities can no longer afford to dispose of waste hydrocarbon streams in their flare systems. Pure streams from polyolefin reactors and vents from polymer-storage facilities, which were once flared, must be redirected to recovery systems. To reduce the economic penalty of environmental compliance, these paraffin and olefin mixtures must be recovered and recycled. In other words, two products must be made, a useful fuel and a useful chemical product, hence more process engineering is required in order to achieve such an objective. 

J. Soarez, T. McKenna, Polymer Reaction Engineering. Polyolefin Reactors and Processes . (Wiley, Hoboken, 2012) doi 10.1002/9783527646944.ch4... 

How can the MGM and effects of reactor residence time be combined to obtain a more complete description of polymerization in industrial reactors Some of these aspects have been discussed in the literature but would require a lengthier treatment than allowed here [87]. Alternatively, a rather simple, but elegant, treatment will be shown, which combines some of the aspects that have been covered in the discussion on micro-, meso- and macroscale phenomena to model polyolefin reactors under steady-state operation. 

The feed pressure was taken arbitrarily at 7 atm in me above simulation. The available pressures in me refinery gas streams and me purge streams from polyolefin reactors are higher man 7 atm. At higher feed pressures, me PSA performance wim AgN03/Si02 will continue to improve because more olefin will be adsorbed, whereas mat wim AIPO4-I4 will not improve because its capacity is already saturated. 

Keywords Catalysis Molecular reinforcement Nanocomposites Olefin polymerization Polymerization filling Polyolefin Reactor blends Single-site... 

In the second strategy, oriented crystallization of polyolefins, the production of in situ polyolefin (nano)fibers or (nano)sheets affords molecular polyolefin composites and effective polyolefin matrix reinforcement without requiring any alien fiber or fillers. Moreover, polyolefin reactor blends containing ultrahigh molecular weight (UHMW) polyolefin can produce in situ UHMW polyolefin... 

M. Takeda, W. H. Ray, Optimal-grade transition strategies for multistage polyolefin reactors , AIChE Journal, 1999, 45, 1776. 

In addition to the two-phase TPEs, two new technologies have emerged. They are the metallocene-catalyzed polyolefin plastomers (POPs, the name given to Exxon s EXACT product line) and polyolefin elastomers (POEs, DuPont Dow Elastomer s ENGAGE), and reactor-made thermoplastic polyolefin elastomers (R-TPOs). These new types of TPEs are often called metallocene elastomers-TPEs (MEs-TPEs) [87]. The new POPs and POEs are essentially very low-molecular-weight-Unear low-density PEs (VLMW-LLDPE). These new-generation TPEs exhibit mbber-like properties and can be processed on... 

The use of two or more different catalysts in the same reactor, sometimes known as in situ reactor blending or tandem catalysis, has been widely employed industrially as means of controlling the properties of a polyolefin (e.g. molecular weight and the molecular weight distribution). Recent years have seen a variety of reports emerge on the use of bis(imino)pyridine iron/cobalt systems as one component of the process [169, 170, 171, 172, 173, 174, 175, 176, 177,178, 179],... 

Catalloy A gas-phase process for making olefin co-polymers, using Ziegler-Natta catalysts. It uses a series of three gas-phase reactors to which monomer is progressively added. The properties of the product can be varied according to the monomer grades used. Developed by Himont and first commercialized in 1990. Now operated by a joint venture of Montell Polyolefins and Japan Polyolefins. See also Hivalloy. 

TPOs, comprising TPEs with a polyolefin matrix and an unvulcanized rubber. They can be produced by blending or by block copolymerization of polypropylene and EPDM (reactor TPOs). Sometimes TPVs are included in TPOs. 

A new type of giant reactor has been developed at Chemische Werke Hiils and tested on a large scale. This reactor has some remarkable properties—a wide range of applicability for different polymerizations and capacities on the order of 20,000 to 50,000 tons per year. Polymerizations which have been successfully tested are suspension and emulsion PVC, polystyrene, polyolefin, SBR-latices, and solution rubber. 

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