Polymerization unit

Phosphates are the principal catalysts used in polymerization units the commercially used catalysts are Hquid phosphoric acid, phosphoric acid on kieselguhr, copper pyrophosphate pellets, and phosphoric acid film on quartz. The last is the least active and has the disadvantage that carbonaceous deposits must occasionally be burned off the support. Compared to other processes, the one using Hquid phosphoric acid catalyst is far more responsive to attempts to raise production by increasing temperature. 

Propylene and butylenes Feed to alkylation or polymerization units... 

Majoros, L, Nagy, A. and Kennedy, /, P, Conventional and Living Carboeationic Polymerizations United. 1. A Comprehensive Model and New Diagnostic Method to Probe the Mechanism of Homopolymerizations. Vol 112, pp. 1-113. 

Denver, Colorado (Refs. 16 and 19) 3 (0 in buildings) A propane release at a polymerization unit in a process plant resulted in a blast that destroyed the process unit. The blast-resistant control house, located only 98 ft (30 m) from the blast center, sustained little damage. 

The poly(5-fnethyl-l, 4-hexadiene) fiber pattern (Figure 6) gave an identity period of 6.3 A, indicating a 3 isotactic helix structure. The X-ray diffraction pattern was not very sharp, which may be due to the difficulty of the side chain with a double bond to fit in a crystalline lattice. The crystallinity was determined to be 15% using the Hermans and Weidinger method (27). A Chloroform-soluble fraction free from catalyst residues showed no improvement in the sharpness of the X-ray diffraction pattern. These data show that the configuration of the 1,2-polymerization units in the homopolymer of 5-methyl-1,4-hexadiene is isotactic. 

The H2O molecule reacts with the bridging oxygens of the polymeric units in silicate melts to form hydroxyl groups OH on their free terminations (Fraser, 1977) ... 

Polymerization units convert olefin feedstocks (primarily propylene) into higher octane polymers. These units generally consist of a feed treatment unit (to remove H2S, mercaptans, and nitrogen compounds), a catalytic reactor, an acid removal section, and a gas stabilizer. The catalyst is usually phosphoric acid, although sulfuric acid is used in some older methods. The catalytic reaction occurs at 150-224°C (300-435°F) and at a pressure of 11.2-137.0 atm (150-2000 psig). The temperature and pressure vary with the subprocess used. 

A polymerization unit containing separate glass ampoules of purified w-hexylisocya-nate, the initiator, and a reaction terminator, was connected to a vacuum and then sealed. The reaction conditions were — 98°C and 1 x 10-6 torr with a reaction time between 5 and 15 minutes. To set the reaction temperature, liquid nitrogen was added to methanol contained in a constant temperature bath to freeze the methanol and the temperature measured using a low-temperature thermometer. The initiator, sodium-benzyl phenyl ketone, was obtained by reacting sodium metal with an equivalent amount of benzyl phenyl ketone in THF and used immediately. The terminator consisted of hydrochloric acid-methanol mixture solution. Reaction scoping results are provided in Table 1. 

Table II. Over-all Material Balance on Thermal Reformer and Polymerization Unit ...

The over-all material balance, prepared for the test period on the combined operation of the thermal reformer and the polymerization unit, appears in Table II. It is based on the streams actually fed and produced. Table III shows the debutanized reformate and debutanized polymer streams separately and as a combined stream. Laboratory inspections of the debutanized reformate and of the debutanized reformate plus polymer blend are presented in Table I. 

Texas, USA 1963 Propylene 3M damage from a fire and explosion in a low pressure polypropylene polymerization unit CVE... 

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