Project Report of Production of Butadiene from Butane part 1.docx

8/17/2019 Project Report of Production of Butadiene from Butane part 1.docx

1/22

2.3 Market :

According to CMAI (2007), global butadiene demand is expected to grow at just under

3 !"#$ear t%roug% 20&2, slig%tl$ abo'e t%e a'erage o 3 2"#$ear growt% o t%e past i'e

$ears emand in India will be t%e largest, growing nearl$ &!"#$ear or t%e next i'e$ears emand in Asia is expected to exceed !"#$ear, alt%oug% demand in some

countries, primaril$ C%ina, will be at more t%an &0", anal$sts sa$ emand in *ort%

America and +estern urope is expected to rise at less t%an &"

Most o t%e capacit$ will be added in Asia, particularl$ C%ina, w%ic% will account or

nearl$ 7!" o new capacit$, added be ore 20&2 -perating rates in Asia are expected to

be strong at .!"/ 0", w%ile operating rates in urope will be %ig%est, at about 0",

anal$sts sa$ -perating rates in *ort% America are expected to %o'er in t%e 70" range,

t%e$ sa$ 1able 2 3 s%ows t%e butadiene producer and production rate in Asia *otice

t%at in Mala$sia, t%ere is onl$ &00,000 mt #$ear production totall$

Country ProducersProduction Rate

(in thousands of MT./year)

C%ina

ang i 4etroc%emical &.!C*--C 5%ell 4etroc%emicals6 &!!Maoming 4etroc%emical &!0

ilin C%emical &608ilu 4etroc%emical &309an %ou 4etroc%emical &205%ang%ai 4etroc%emical &20

ans%an 4etroc%emical &&3-t%ers 3 !1otal &!0.

India:eliance Industries &!0-t%ers &721otal 322

apan

apan 5$nt%etic :ubber 2;.C%iba a$ama


2/22

9? C%emical &6!9otte aesan 4etroc%emical &05amsung 4etroc%emicals9? aesan 4etroc%emical .5@ Corp 725@ nerg$ 721otal &0&.

Mala$sia 1itan 4etc%em &001otal &00

5ingapore ;01otal ;0

1aiwanormosa 4etroc%emical 373

C%inese 4etroleum &731otal !6;

1%ailand

o> 5$nt%etics &60

I:4C! ;!1otal 20!Average: !"."#$%&

2.! 'utadiene Manufacturing Process nfor ation :

ing o 4ara inic $drocarbonsB In t%is process, butadiene is a co/ product

in t%e manu acture o et%$lene (t%e et%$lene co/product process)

2) Catal$tic e%$drogenation o n/ing process is reported to be t%e predominant met%od o t%e t%ree

processes o production, accounting or greater t%an &" o t%e worldEs butadiene

suppl$ igure depicts a low c%art or a t$pical ole ins plant +%ile t%is does not

represent an$ particular plant, and t%ere are certainl$ man$ 'ariations among ole ins

plants, t%is representation will pro'ide t%e reader wit% a general understanding o t%e

process


3/22

1%e indicated eedstoc>s (et%ane, propane, butane, nap%t%a and gas oil) are ed to a

p$rol$sis (steam crac>ing) urnace w%ere t%e$ are combined wit% steam and %eated to

temperatures between approximatel$ &6!0/&!2! F (7 0/.30 FC) +it%in t%is

temperature range, t%e eedstoc> molecules Gcrac>G to produce %$drogen, et%$lene,

prop$lene, butadiene, ben ene, toluene and ot%er important ole ins plant co/products

A ter t%e p$rol$sis reaction is Huenc%ed, t%e rest o t%e plant separates t%e desired

products into streams t%at meet t%e 'arious product speci ications 4rocess steps include

distillation, compression, process gas dr$ing, %$drogenation (o acet$lenes), and %eat

trans er 1%e ocus o t%is re'iew is &,3/butadiene %owe'er, since butadiene is created in

t%e ole ins plant p$rol$sis urnace, and is present in t%e crude butadiene product stream

at concentrations up to approximatel$ 7! wt", t%e ole ins plant process and t%e crude

butadiene stream are addressed in t%is publication to a limited degree

1%e low pat% o t%e C6 components (including butadiene) are indicated b$ bold JredK

lines


4/22

+%ile some ole ins plant designs will accommodate an$ o t%e listed eedstoc>s, man$

ole ins plants process onl$ *atural ?as 9iHuids (*?9s) suc% as et%ane, propane and

sometimes butane 1%e mix o eedstoc>s, t%e conditions at w%ic% t%e eedstoc>s are

crac>ed, and t%e p%$sical plant design, ultimatel$ determine t%e amount o eac% product

produced, and or some o t%e streams, t%e c%emical composition o t%e stream

2.!.2 'utadiene Production via Cata ytic ehydrogenationof n0'utane and n0

'utene (the ,oudry 1rocess)

1%e catal$tic de%$drogenation o n/butane is a two/step process initiall$ going rom n/

butane to n/butenes and t%en to butadiene


5/22

in t%e reactor is approximatel$ !/&! minutes As t%e endot%ermic reaction proceeds, t%e

temperature o t%e catal$st bed decreases and a small amount o co>e is deposited In

t%e regeneration c$cle, t%is co>e is burned wit% pre%eated air, w%ic% can suppl$

essentiall$ all o t%e %eat reHuired to bring t%e reactor up to t%e desired reaction

temperature

1%e reactor e luent goes directl$ to a Huenc% tower, w%ere it is cooled 1%is stream is

compressed be ore eeding an absorber#stripper s$stem, w%ere a C6 concentrate is

produced to be ed to a butadiene extraction s$stem or t%e reco'er$ o %ig% purit$

butadiene

2.!.3 'utadiene Production via idative ehydrogenation

of n0'utenes (the o0 or 040 1rocess)

-xidati'e de%$drogenation o n/butenes %as replaced man$ older processes or

commercial (on/purpose) production o butadiene 5e'eral processes and man$ catal$st

s$stems %a'e been de'eloped or t%e ox$de%$drogenation o eit%er n/butane or o n/

butene eedstoc>s in t%is process ma$ not be

practical

In general, in an ox$de%$drogenation process, a mixture o n/butenes, air and steam is

passed o'er a catal$st bed generall$ at low pressure and approximatel$ 30/&&&0 F

(!00/;00 FC) 1%e %eat rom t%e exot%ermic reaction can be remo'ed b$ circulatingmolten %eat trans er salt, or b$ using t%e stream externall$ or steam generation An

alternate met%od is to add steam to t%e eed to act as a %eat sin> 1%e %eat can t%en be

reco'ered rom t%e reactor e luent :eaction $ields and selecti'es can range rom 70/

0", ma>ing it unnecessar$ to reco'er and rec$cle eedstoc>


6/22

'utadiene Production via idative ehydrogenation

In t%e -xo/ process s%own in igure, a mixture o air, steam, and n/butenes is passed

o'er t%e de%$drogenation catal$st in a continuous process 1%e air eed rate is suc% t%at

an ox$gen#butene molar ratio o approximatel$ 0 !! is maintained, and t%e ox$gen is

totall$ consumed A steam to butene ratio o &0B& %as been reported as necessar$ to

absorb t%e %eat o reaction and to limit t%e temperature rise

1%e reactor e luent is cooled and t%e C6 components are reco'ered in an

absorber#degasser# stripper column combination 1%e lean oil lows rom t%e bottom o

t%e stripper bac> to t%e absorber, wit% a small amount passing t%roug% a sol'ent

puri ication area Crude butadiene is stripped rom t%e oil, reco'ered in t%e o'er%ead o

t%e stripper, t%en it is sent to a puri ication s$stem to reco'er t%e butadiene product

2.!.! Conc usion of Product +e ection :


7/22

Comparisons or all our products %a'e been tabulated in 1able 2 6 et demand especiall$ in Asia region emand in Asia will grow at a

more rapid rate, at !" #$ear, alt%oug% demand in some countries, particularl$ C%ina,

will be at more t%an &0"#$ear (CMAI, 2007)

• ig% mar>et pricing o L5 0 ;6#lb w%ic% will gi'e %ig%er pro it

• -nl$ one competitor in Mala$sia, w%ic% is 1itan 4etc%em (M) 5dn


8/22

agriculture

c%emical

and oil

additi'es

construction

mar>et

1%e process w%ic% is %ere described in t%e project among t%ese t%ree processes is t%e

production o t%e n/


9/22

. Production rates:

4lant t%at %as a capacit$ t%at is greater t%an &0 x &0; Ib#$r is usuall$ continuous In

contrast, i t%e plantNs capacit$ is less t%an & x &0; Ib#$r, t%en batc% process will be

c%osen ind o process instead o continuous


10/22

i' I a eed impurit$ is present in large amounts, remo'e it

' I a eed impurit$ is present as an a eotrope wit% a reactant, o ten it is better to

process t%e impurit$

'i I a eed impurit$ is inert but is easier to separate rom t%e product t%an t%e eed, it

is better to process t%e impurit$

'ii I a eed impurit$ is a catal$st poison, remo'e it

1able s%ows t%e composition o t%e component in eed 1%e main component t%at is to

be used in butadiene production is n/butane owe'er, t%e amount o isobutane in t%e

stream is large (3 3 mole ") I isobutane is not separated rom t%e eed and is

processed, additional b$ product mig%t be produced and t%us complicated t%e separation process downstream 1%is will imposed additional cost (capital and operating) to t%e

plant ence, wit% re erence to guideline i and i', t%e team decided to puri $ t%e stream

irst be ore entering to t%e reactor

Ta- e : Composition of the Components in the Feed

Co 1onent ;or u a Mo e <

4ropane

i/


11/22

;igure : 4uri ication o t%e eed

igure s%ows t%e sc%ematic diagram o t%e eed puri ication section istillation column

is used to separate t%e impurities rom t%e eed As s%own in t%e diagram, n/butane will

be wit%drew as side draw product, w%ile isobutane and propane will be wit%drew rom

t%e distillation column as t%e top product and C!O as bottom product

1o con'ert n/butane to butadiene, two stages o de%$drogenation reaction are in'ol'ed(non/oxidati'e and oxidati'e de%$drogenation) 1%e b$ product o t%e processes are

%$drogen ( 2), carbon monoxide (C-), carbon dioxide (C- 2), s%ort c%ain %$drocarbon

(C&/C3) and steam ( 2-) igure 6 3 s%ows t%e sc%ematic diagram o two stages o

de%$drogenation process -nl$ approximatel$ 33" o n/butane will be con'erted to

butadiene ence t%e unreacted n/butane will be rec$cled

;igure : 1wo 5tages e%$drogenation o n/butane


12/22

5ince onl$ approximatel$ 33" o n/butane will be con'erted to butadiene, t%e unreacted

n/butane will be rec$cled a ter separated o t%e product stream It is impossible to

ac%ie'e s%arp separation in t%e separation process ence, t%e rec$cle stream will

consist o low raction o impurities ence, part o t%e rec$cle stream will be purged to

a'oid accumulation o t%e impurities in t%e process stream

2.# n1ut ut1ut +tructure B

2.% R6C C86 / R6ACT R + 5T,6+ +

?ood reactor per ormance is o paramount importance in determining t%e economic

'iabilit$ o t%e o'erall design and undamentall$ important to t%e en'ironmental impact


13/22

o t%e process (5mit%, 200!) 1%ere ore, issues to be addressed or a good reactor design

s%ould include

& :eactor t$pe

2 Catal$st

3 5i e

6 -perating Conditions (1emperature and 4ressure)

! 4%ase

; eed Conditions (Concentration and temperature)

At earl$ stages in design, a >inetic model normall$ is not a'ailable 1%us, material

balance calculations s%ould be based on a correlation o t%e product distribution

( ouglas, & .) 1%is t$pe o >inetic anal$sis is 'er$ crude but in most cases t%e reactor

cost is not nearl$ as important as t%e product distribution costs

2.%. Reactor +e ection

1%e selection o reactor is cruciall$ important in order to ma>e sure t%at t%e eed

operates at its maximum or single reaction, t%e %ig%est rate o reaction is maintained

b$ t%e %ig%est concentration o eed (5mit%, 200!)


14/22

temperature control because %eat loads 'ar$ t%roug% t%e bed 1emperature in t%e catal$st

mig%t become locall$ excessi'e, w%ic% ma$ lead to undesired product and catal$st

deacti'ation 1%e catal$st is usuall$ troublesome to replace too ed


15/22

isad'antages

• i icult to control t%e

temperature because %eat loads 'ar$

t%roug% t%e bed

•

1emperature in t%e catal$st becomes locall$ excessi'e, w%ic% ma$

lead to undesired product and catal$st

deacti'ation

• 1%e catal$st is usuall$

troublesome to replace

• C%anneling o t%e gas low

occurs, resulting in ine ecti'e use o parts o t%e reactor bed

• ig% cost o t%e reactor

and catal$st regeneration

eHuipment

•

Attrition o catal$stcan cause generation o catal$st

ines w%ic% could be carried o'er

and lost in t%e s$stem, and ma$

cause ouling in pipelines and

eHuipment downstream

• 4re erable or gas/solid

non/catal$tic reactions

A ter comparing bot% t$pes o reactor, tubular ixed/bed catal$tic reactor is c%osen or

all t%ree reactors in'ol'e in t%e process 1%is is due to t%eB

a lower capital and operating cost

• 1%e reactions in'ol'ed in t%e butadiene production are reHuired to be operated in

%ig% pressure condition

• 1%e reHuired 'olume or tubular ixed bed catal$tic reactor is smaller compared

to luidi ed bed reactor or %ig% pressure operation, and t%us lower capital cost

• 1%e operating cost or luidi ed bed reactor is 'er$ %ig% because it is more

di icult to maintain t%e gas p%ase reactant and catal$st to be in t%e well mixed

condition i it is operated in %ig% pressure

b less losses in catal$st

• 1%ere will be losses in catal$st i luidi ed bed reactor is selected

• 1%e losses in catal$st are resulted romB

• catal$st will settle at t%e bottom o t%e reactor i it is not well mixed wit% t%e gas

p%ase reactant

•

catal$st ine mig%t be generated during t%e operation o t%e reactor w%en t%ecatal$st %it on t%e wall o t%e reactor or t%roug% attrition 1%e catal$st ine will


16/22

be broug%t to t%e downstream o t%e process w%en toget%er wit% t%e product

stream

c lower maintenance cost

• I luidi ed bed reactor is selected, t%e catal$st t%at settle at t%e bottom o t%e

reactor will oul and plug t%e reactor w%ile t%e generated catal$st ine will cause

ouling in t%e pipeline and eHuipment downstream

• 4lant mig%t need to be s%ut down o ten or maintenance

2.$ +6PARAT 5 +TR7CT7R6

1%e core reaction in butadiene production is t%e de%$drogenation using n/butane as t%e

reactant owe'er, t%e eed stream contains signi icant amount o i/butane w%ic% is up

to 3 3" 1%us, in order to increase $ield, we need to con'ert i/butane into n/butane

1%e con'ersion is done in t%e Isomeri ation :eactor

1%e deisobutani er column in pretreatment section emplo$s side draws to $ield puri ied

n/butane 1%e n/butane stream is drawn as a 'apor side product a ew tra$s abo'e t%e

bottom, lea'ing a small %ea'$ end stream w%ic% is onl$ about &" o t%e eed stream to

be t%e bottom product 1%us, t%e s$stem consists o two prominent products and we can

assume t%at t%e small stream does not exist

1%e initial assumption or distillation columns is to %a'e 0 02 mole percent o lig%t >e$

component in bottom and 0 0& mole percent o %ea'$ >e$ component in t%e o'er%ead

product Also, we assume t%at all t%e component lig%ter t%an t%e lig%t >e$ lea'e wit%o'er%ead and t%at all components %ea'ier t%an t%e %ea'$ >e$ are ta>en at t%e bottoms

2.$. esign of 6 tractive isti ation Co u n :

According to 5eader (& .), extracti'e distillation is a partial 'apori ation process in

t%e presence o a miscible, %ig%/boiling, non/'olatile mass separation agent, normall$

called t%e solvent, w%ic% is added to an a eotropic or non/a eotropic eed mixture to

alter t%e 'olatilities o t%e >e$ components wit%out t%e ormation o an$ additional

a eotropes


17/22

2.$.2 +o vent se ection:

5ince t%e sol'ent is t%e %eart o extracti'e distillation, more attention s%ould be paid on

t%e selection o potential sol'ents 1%e a init$ o %$drocarbon to polar sol'ent depends

directl$ on t%eir degree o un/saturation A %ig%l$ unsaturated %$drocarbon is moresoluble in a polar sol'ent, and t%e sol'ent decreases t%e 'olatilit$ o t%e %$drocarbon

, se'eral eatures are essentialB

& 1%e sol'ent must be c%osen to a ect t%e liHuid/p%ase be%a'ior o t%e >e$

components di erentl$ ot%erwise no en%ancement in separabilit$ will occur

2 1%e sol'ent must be %ig%er boiling t%an t%e >e$ components o t%e separation and

must be relati'el$ non'olatile in t%e extracti'e column, in order to remain largel$ int%e liHuid p%ase

3 1%e sol'ent s%ould not orm additional a eotropes wit% t%e components in t%e

mixture to be separated

6 1%e extracti'e column must be a double/ eed column, wit% t%e sol'ent eed abo'e

t%e primar$ eed t%e column must %a'e an extracti'e section

rom LllmanNs %andboo> (& .!), t%ere are i'e sol'ents t%at are commonl$ used in

industr$Ba n/met%$l/2/p$rrolidone (*M4),

b dimet%$l ormamide ( M )

c imet%$lacetamide ( MAC)

d Acetonitrile (AC*)

e ur ural

- all possible sol'ents t%at can be used or t%e separation o butadiene/butane mixture

we %a'e c%osen dimet%$l ormamide ( M ) M is recommended as a potential

entrainer because it gi'es great alteration in relati'e 'olatilit$ 1%is in turn will ma>e t%e

separation easier and c%eaper, as t%e utilities and tra$s reHuired are lesser 'en t%oug%

*M4 gi'es greater 'alue, it costs almost twice t%e M


18/22

C,APT6R 3: PR C6++ 6+CR PT 5


19/22

Process escri1tion

In t%is project, butadiene is produced in continuous process ere t%e &,3/butadiene is

produced b$ oxidati'e de%$drogenation reaction

3. Pre1rocess Purification > eiso-utani=er :


20/22

3

4

6

C-101

E-101

E-102

;igure : 4reprocess 4uri ication 5ection

1%e main objecti'e o t%is pre/treatment unit is to extract n/butane rom t%e eed 1%e

extracted n/butane will be used as t%e reactant or t%e de%$drogenation process in order

to produce butadiene

1%e eed omposition is as ollows B

Ta- e : eed Composition

Co 1onent ;or u a Mo e


21/22

4ropane

i/


22/22

1%e process gas rom 5ection &, t%e preprocess unit enters t%e urnace ( 30&) at

62 2oC 1%e urnace will %eat up t%e process gas up to ;00 oC 1%e %eated process gas

will enter t%e e%$drogenation :eactor (:30&) w%ere t%e n/butane will be con'erted in

to butenes $drogen and ot%er b$product suc% as C & P C3 will also orm 1%e

e%$drogenation :eactor (:30&) is a ixed bed tubular reactor operating at temperature

o !00oC and pressure o 3 bar 1%e reaction is an exot%ermic reaction and t%e

temperature is maintained using molten salt at t%e s%ell side o t%e reactor 1%e catal$st

used in t%e reactor is t%e Pt ?.3 +n ?.# Cs ?.&@ ?.& 8a 3.? w%ic% gi'es t%e con'ersion o 32 "

and selecti'it$ o ;"

1%e butenes rom :30& will be cooled down rom ;00 oC to 620 oC b$ e%$drogenationInter/cooler ( 30&) be ore urt%er supplied to -xidati'e e%$drogenation :eactor(:302) 1%e :302 is also a ixed bed tubular reactor and is operating at temperature o330 oC and pressure o 3 bar

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Project Report of Production of Butadiene from Butane part 1.docx

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