Unipol PP process

Unipol PP process Unipol process Uniprocessor computers UNIQUAC UNISITALE process... 

Fig. 12. Unipol PP process where A is the polymerization reactor B, recycle gas compressor C, recycle gas cooler D, product discharge tank E, impact copolymer reactor F, recycle gas compressor G, recycle gas cooler and H, product discharge tank (134).

Application To produce homopolymer, random copolymer and impact copolymer polypropylene using the Dow gas-phase UNIPOL PP process. 

The UNIPOL PP process simple, direct nature results in low investment and operating costs, low pollution levels, minimal potential fire and explosion hazards, and easy operation and maintenance. To produce homo polymers and random copolymers, gaseous... 

Proprietary catalyst and donor systems The Dow Chemical Co. manufactures and provides a family of polypropylene catalysts (SHAC catalyst) and a family of external electron donors (SHAC ADT) for use in the UNIPOL PP process. SHAC catalyst offers high catalyst activity (up to 35 kg/g-hr using conventional external donor and up to 60 kg/g-hr using a SHAC ADT) and competitive polymer properties. SHAC ADT performs three functions ... 

Licensor The Dow Chemical Co. Univation Technologies is the licensor of the UNIPOL PP process. - CONTACT... 

Unipol PP process Unipol PP process Spheripol process (in combination with a loop reactor)... 

Fluidized bed reactors are used for the gas phase polymerization of olefins to produce LLDPE and HDPE (Unipol PE, Innovene and Spherilene processes [22]) as well as for the manufacture of polypropylene (Unipol PP process [22]). The residence time distribution of a fluidized bed reactor is close to that of a well mixed continuous reactor. Therefore, the use of a single fluidized bed reactor leads to a broad particle size distribution and to large variations in the catalyst productivity from particle to particle. The use of two fluidized bed reactors in series narrows the residence time distribution leading to a more uniform product. 

The Unipol PP process combines the Union Carbide fluid bed technology developed for polyethylene with the Shell supported high yield catalysts (SHAC). 

In gas phase processes, gaseous propylene comes into contact with the solid catalyst which is intimately dispersed in dry pol5aner powder. Industry uses two different methods of carrying out this reaction depending on the chosen method of heat removal. The Unipol PP process uses a modification of the Unipol polyethylene fluidised bed system. The Novolen PP process and Innovene PP process use mechanically agitated dry powder beds with evaporative cooling in vertical and horizontal reactors, respectively. Unipol PP was originally developed by Union Carbide and Shell, the Novolen PP process by BASF and the Innovene PP process by Amoco. 

During the 1970s Jersey Standard s chemical product portfolio had been reduced to resemble that in 1960. Its primary chemical business remained the production of ethylene, basic polymers (including LDPE, linear low-density polyethylene (LLDPE) using the Unipol process, licensed from Union Carbide, PP, and polyvinyl chloride (PVC), plasticizers (particularly for vinyl production), elastomers, and synthetic rubbers. Profits returned. The 1974 balance sheet listed earnings of 456 million on revenue of 3.3 billion, making Exxon Chemical one of the five most profitable chemical companies worldwide. 

The Unipol low-pressure gas-phase fluidized-bed process, which was introduced by Union Carbide in 1977 for LLDPE, has also been adapted to the production of PP homopolymers and block copolymers using Shell Chemicals high-activity (Ziegler-type) catalyst technology. The Spheripol and Unipol... 

In 1979, the UNIPOL process for gas-phase production of LLDPE was introduced by the Union Carbide Corp. Since the new resins were difficult to process on the lines designed for LDPE, by 1982 several patents were issued for improvement of LLDPE processability by blending it with other polyolefins, viz., LDPE, PP, and olefinic rubbers. Ethylene copolymers, rubbers, EPDM, EVAc, maleated polypropylene, EPR, etc., have also been used (Cowan 1983 Turtle 1983 Fukui et al. 1983 Haas 1983 Hert 1983). Thus, blends LLDPE/LDPE were found miscible at low LDPE contents, then immiscible at high LDPE. Addition of HDPE as cosolvent resulted in miscible tertiary blends (Lee and Denn 2000). 

In 1979 UNIPOL process for gas-phase production of LLDPE was introduced by the UCC. Since the new resins were difficult to process on the LDPE processing lines, several patents were issued for LLDPE blends with, e.g., LDPE or PP, which had better processability In 1982 a number of patent applications for blends of LLDPE, with other polyolefins, co-polyolefins, and olefinic elastomers, for example, ethylene copolymers and thermoplastic elastomers (e.g., TPO, EPDM, EPR, EVAc, PP-MA,), have been filed... 

Burdett ID. A continuing success the UNIPOL process. Chemtech, pp 616-623, October 1992. 

The Unipol process is noted for its ease and flexibility of operations. Here heterogeneous MgCl -supported Ti catalysts are used for the manufacture of LLDPE or PP in fluidized bed reactor. The solid catalyst in an inert liquid medium is fluidized and reacted with the gaseous reactants. In PP manufacturing the use of liquid propylene as a reaction medium is also well-established. The polymerization is carried out in loop reactors using morphology-controlled Zeigler-Natta catalysts. 

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