Abstract
Polypropylene is a type of thermoplastic polymer resin and a superior quality polymer material material that originates from olefins. olefins. Polypropyle Polypropylene ne (PP), (PP), also known as polypropene, polypropene, is a thermoplastic polymer used used in a wide variety of applications. With the rising demands of polyprop polypropyl ylene, ene, now it become becomes s the second second importa important nt plasti plastic c produc product. t. Polyme Polymeriz rizati ation on occurre occurred d in product production ion of Polypr Polypropy opylen lene e with with the overal overalll process process is known known as free radicals. here are few ways to manufacture Polypropylene in manufacturing industry. !owever, the latest technology had discovered that production of Polypropylene can be optimized using "luidized #ed $atalytic %eactor ("#%) with &iegler ' atta $atalyst acting as catalyst in the reaction. "#% are heterogeneous reactor where mass of catalyst being fluidized, fluidized, and etensive etensive miing miing in all direction is allowed allowed to happen. "luidization "luidization happened when a fluid is passed through a solid granular material (catalyst shaped as tiny spheres) spheres) at high velocities velocities to suspend solid to cause it behaving behaving as though it were a liquid. liquid. his his result results s ecell ecellent ent tempera temperature ture stabili stability ty and increas increased ed mass mass transf transfer er and reaction reaction rates. $apability $apability to handle large amount amount of feed and catalyst is the advantages advantages of "luidized #ed $atalytic %eactor. *n industry, products that can be manufactured from Propylene Propylene are plastic plastic products products like chairs, labelling labelling and packaging, packaging, tetiles, tetiles, stationery, stationery, laboratory equipment and many other.
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Introduction
!istory of process *n +arch -/, Polypropylene was first polymerized to a crystalline isotactic polymer by 0iulio atta and 0ermany chemist, 1arl %ehn. he discovery led to large scale commercial production by *talian firm +ontecatini from -2 onwards. atta and his co3 workers also the first to synthesise 4yndiotactic Polypropylene. With revenues epected to eceed 546 / billion by 78-, Polypropylene is the second most important plastic. he demand for this material was growing at a rate of /./9 per year between 788/ and 787.
Process methods
ype of reaction: Polymerization %eaction mechanism: ;verall process is known as free radical addition. $hain initiation: he chain is initiated by free radicals, %a , produced by reaction between some of the ethene and the oygen initiator. $hain propagation:
$hain termination: wo free radicals hit each other producing a final molecule. he process stops here because no new free radicals are formed.
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$hain termination is a random process, poly(ethene) will be made up of chains of all sorts of different lengths. %eactant: Propene, !ydrogen Product: Polypropene (polypropylene) $atalyst: &iegler ' atta catalyst
=pplication of product and its importance Polypropylene is widely used an a wide variety of applications including packaging and labelling, tetiles, stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes.
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Reactor
ypes of main reactor and its description *n optimizing Polypropylene production, "luidized #ed %eactor ("#%) is being used. "#% are heterogeneous catalytic reactor where mass of catalyst is fluidized, allowing etensive miing in all direction. "luidization is where a fluid is passed through a solid granular material (catalyst shaped as tiny spheres) at high velocities to suspend solid to cause it behaving as though it were a liquid. his results ecellent temperature stability and increased mass transfer and reaction rates.
"#% are capable to handle large
amount of feed and catalyst.
4ize or dimension he inner diameter and height of the fluidized bed zones are 8 cm and 8 cm, respectively. he diameter is based upon the capacity of the production and the height of the reactor based on the fluid residence times. he disengagement zone has a diameter of 7 cm and a height of 7 cm.
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4upportive equipment or units o operate this reactor, few other supportive equipment and units required to produce Polypropylene. hey are compressor, heat echanger and polymer > reactant separator. $onstraints or problem of reactor "luidized bed reactors usually are more comple to design, build and operate compared to other reactors. his reactor also prone to erosion and particle attrition caused by moving particles. 4olid losses causes significant operating costs especially when solid particles are an epensive catalyst. *t is also needed to manage the bubbles as bigger bubbles can travel faster than smaller bubbles, which reduces mass transfer between phases. %eactor operating conditions "#% is being operated at temperature range ?78 to ?@8 1. = pressure ranging from A to ? atm needed to operate "#%. $atalyst and co3catalyst are continuously fed into reactor to activates the reactants which is Propylene and !ydrogen, producing an outspread distribution of polymer particles. While activating catalyst, keeping moisture below 7 ppm done by co3catalyst. his is required in producing industrial grade polypropylene. Propylene can converted to Polypropylene as much as 7 to ? percent per pass under fluidization conditions while overall conversion can reach up to -A percent.
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=dvantages and disadvantages he advantages of using "luidized #ed $atalytic %eactor in optimizing Polypropylene production are: 1 – Uniform Particle Mixing
"luidized beds does not eperiencing poor miing as in packed beds.
Packed bed eperiencing problem where local hot or cold spots within reaction bed and this has been avoided in fluidized situation. emperature differences can resulting product degradation. "#% is perfect for eothermic reactions. 3 – Reactor able to operate in continuous state
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$ontinuous withdraw of product and entering of new reactants into reaction vessel is being allowed due to fluidized bed nature. $ontinuous process operation can make manufacturers to be able to produce various products, efficiently.
!owever, "luidized #ed $atalytic %eactor also possessed some disadvantages:
1 – ac! of current understanding
here are limited current understanding of the actual behaviour of materials in a fluidized bed. Prediction and calculation of comple mass and heat flows within the bed is difficult. 2 – Pressure loss scenarios
*f fluidization pressure is lost all of sudden, surface area of bed may be reduced. his can be inconvenience and may have serious implications. 3 – "rosion of internal components
he fluid like behaviour of fine solid particles within the bed can causes wearing of the reactor vessel. <pensive maintenance for reaction vessel and pipes is required.
#onclusion and Recommendations
o conclude, research found that latest technology "luidized #ed $atalytic %eactor helps to optimize the production of polypropylene. "luidization is where a fluid is passed through a solid granular material (catalyst shaped as tiny spheres) at high velocities to suspend solid to cause it behaving as though it were a liquid. his results ecellent temperature stability and increased mass transfer and reaction rates. "#% are capable to handle large amount of feed and catalyst.
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here are a few advantages of using "luidized #ed $atalytic %eactor in production of polypropylene. 5sage of "#% are advantageous as it helps to mi particles uniformly, temperature gradients becomes uniform and reactor able to work continuously. !owever, the discovery is still new. here is still lacking knowledge of the reactor. 4everal constraints of the reactor has been founded. herefore, further study about the reactor is recommended to reduce the constraints and disadvantages. he research aimed to produce more accurate models of inner movements and phenomenon of the bed. his helps chemical engineers in designing better, more efficient reactors to deal with current disadvantages of the reactor and epand the range of usage of "luidized #ed $atalytic %eactor.
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References
3 http:>>www.essentialchemicalindustry.org>polymers>polypropene.html 7 3 https:>>en.wikipedia.org>wiki>Polypropylene ?3 http:>>www.plasticseurope.org>what3is3plastic>types3of3plastic3 /A>polyolefins>polypropylene.asp / 3 http:>>www.aiche.org>sites>default>files>cep>78/7.pdf 3 http:>>chemed.chem.purdue.edu>genchem>topicreview>bp>polymer>reactions.html @ ' %ay $occo, 4.# %eddy 1arri, ed 1nowlton (78/). *ntroduction to "luidization. Particulate 4olid %esearch: 7377. 2 ' !ideki 4ato, !iroyuki ;gawa (788-). %eview on Bevelopment of Polypropylene +anufacturing Process. %CB %eport, D45+*;+; 1=0=15E, **: 3-. A ' +ohammad Fakir !ossain 1han, +ohd =zlan !ussain, *qbal +uhammed +uGtaba (78/). Polypropylene Production ;ptimization in "luidized #ed $atalytic %eactor ("#$%): 4tatistical +odelling and Pilot 4cale <perimental Halidation. +aterials 78/, 2: 7//837/A. - 3 $arl W. 4chroeder , Foseph %. Webster (788). 5.4. Patent o. /7/82. "eb 2, -A 8 ' Iouis heodore (787). $hemical %eactor =nalysis C =pplications for the Practicing
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