Biodiesel Pilot Plat

7/23/2019 Biodiesel Pilot Plat

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1.0 INTRODUCTION

On 12thMay 2015, the 3rdyear student of Chemical Engineering Technology (B! had an

o""ortunity to #isit $T%M Biodiesel &ilot &lant' This #isit is a "art of teaching and learning

(&&! "lanning for &rocess Control (B)30*03! su+ect' -s an outcome from the #isit it is a

re.uirement for the student to come out /ith a re"ort to summarie the /hole e"erience and

no/ledge gained' The re"ort is also a re.uirement to fulfil the su+ect assessment'

1.1 Objective of the visit

i' To e"ose and gi#e +etter understanding of the industrial "rocess control system to

the student'

ii' To ena+le the student in determining the "rocess control that im"lemented in the

Biodiesel &ilot &lant feed4for/ard, feed+ac or cascade control system'

iii' To gi#e hand on e"erience and no/ledge in "rocess control system'

i#' To study the "rocesses of +iodiesel "roduction'

1.2 Backgroun of Bioiese! "i!ot "!ant

Biodiesel is a clean +urning alternati#e fuel "roduced from domestic and rene/a+le

resources' t is sim"le to use, +iodegrada+le, nontoic, and en#ironmental friendly as it is free

of sul"hur and aromatics' Chemically, +iodiesel is a fuel com"osed of mono4alyl ester oflong chain fatty acids deri#ed from #egeta+le oils or animal fats' n the recent years, +iodiesel

has attracted the attention of many researchers and engineers /orld/ide to etend the

lifetime of the fossil4+ased fuel' ssues in the en#ironments, the limited in#estments of

"etroleum, and the high cost of +iodiesel as /ell as the oil "rice insta+ility in the maret,

among other things, are the maor dri#ing forces in conducting research and de#elo"ment in

the rene/a+le energy sector either in the la+ scale or the industrial one'

The "ilot "lant in $T%M /ith a ca"acity at one metric ton (MT! and o"erated in

+atch mode under a su"er#isory control and data ac.uisition (6C-7-! system, has +een

constructed to strengthen a "romising research in area of rene/a+le energy' Crude "alm oil

(C&O! is chosen as the dominant feedstoc due to the a+undance of this cro" in the 6tate of

8ohor /hich is also the +iggest "roducer of "alm oil in the &eninsular of Malaysia /ith

around 0'* Mha of the "lantation area for the "alm trees' O/ing to the grandness of the "alm

oil to the community and to sustain the inherently local strength, $T%M has taen a "ractical

initiati#e to e"lore the "otential role area in the refinery of the +iodiesel "roduction'


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The +iodiesel "ilot "lant is a significant "latform es"ecially for conducting research

and de#elo"ment in area of alternati#e energy resources that are "lentiful a#aila+le in 8ohor'

This "ilot "lant re"resents the real commercial +iodiesel "lant ho/e#er in smaller scale' The

+atch technology of the "ilot "lant ena+les us to study the "erformance of each unit o"eration

or a "lant re#am"ing if necessary /ithout interfering the "roduction "rocesses, test the

o"era+ility of a control system, o+tain inetic data, determine the economic feasi+ility or ne/

"rocess, gain the design data, screen catalysts, "ro#e areas of ad#anced technology, and

"ro#ide data for solutions to scale4u" "ro+lems along /ith technical su""ort to an eisting

"rocess or "roduct' The en#ironmental im"act studies such as toic dis"ersion model, /aste

/ater, and assessing "rocess haards are interesting areas of choices' -dditionally, the "ilot

"lant may gi#e +etter im"ression and ins"iration to the students during e"erimental

acti#ities'

9igure 1: The $T%M Biodiesel &ilot &lant

9igure 2: The +loc flo/ diagram of the "lant design


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9igure 3: &lant layout inside the +uilding


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9igure ;: O#erall "lant layout "lan (unscaled!


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2.0 CONT#NT O$ %I&IT

2.1 B!ock f!o' iagra( of )rocess contro! an )rouction of bioiese! )!ant

9igure 5: Bloc 9lo/ 7iagram of the "roduction of Biodiesel &lant


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2.2 "rocess escri)tion

The "rocess "roduction of the "lant to "roduce +iodiesel consists of "re4treatment, esterification,

transesterifcation, methanol reco#ery and +iodiesel refinery'

2.2.1 "re*treat(ent

Crude "alm oil (C&O! stored in a heated storage tan is "um"ed into the "re4treatment "lant for

the degumming and +leaching "rocesses' n the degumming stage, "hos"horic acid (0'5 g! is

added to condition gums together /ith the +leaching earth' The "hos"holi"ids, trace metals,

oidation "roducts, and "igments are remo#ed' The o"erating conditions are e"t under #acuum

at a tem"erature of C to mae the C&O free of moisture' The dried oil is treated /ith

+leaching earth or clay (10 g! to adsor+ the residual colour' The miture of oil is the "assed

through to the 10 ?m filter for se"aration of the s"ent earth from the oil' The o+tained oil refined

in the "re4treatment "lant is a +leached, degummed, dry crude oil and yello/4reddish in colour'

2.2.2 #sterification

The esterification "rocess is re.uired if the feedstoc has more than 0'5 @ +y /eight of free fatty

acid' Esterification increases the yield of +iodiesel' Ahen oil feedstocs contain an ecess of free

fatty acids they ha#e to go through the "rocess of esterification' The ey to effecti#ely "re"aring

for the esterification "rocess is to mae sure the feedstoc ha#e +een sufficiently filtered +y

remo#ing all contaminants and /ater' $"on filtration the feedstocs are fed to the acid

esterification "rocess' The catalyst, sul"huric acid, is dissol#ed in methanol and then mied /ith

the "re4treated oil' Once the miture is heated and stirred, the free fatty acids are con#erted to

+iodiesel' The final ste" of esterification is to de/ater and feed the "roduct to the

transesterification "rocess'

2.2.+ Transesterification

The transesterification of the oil is used to con#ert the remaining oil com"letely into +iodiesel'

This "rocess and esterification are the core "rocesses in the +iodiesel "roduction' Oil feedstocs

containing small amounts of free fatty acids are fed directly to the transesterification "rocess'

The catalyst, "otassium hydroide, is dissol#ed in methanol and then mied /ith the "re4treated

oil' The co4"roducts of this reaction are +iodiesel and glycerine'


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2.2., -ethano! recover

Methanol is usually remo#ed after the +iodiesel and glycerine ha#e +een se"arated into t/o

layers, "re#enting reaction re#ersal' The methanol is then cleaned and recycled +ac to the

+eginning of the "rocess'

2.2./ Bioiese! refining

Once se"arated from the glycerine, the +iodiesel goes through a "urification "rocess, remo#ing

all remaining alcohol and catalyst' t is then dried and stored' To guarantee the +iodiesel is

/ithout colour, odour and sul"hur, an additional distillation "rocess may +e im"lemented' The

do/nstream "rocesses are em"loyed for the "urification of the crude +iodiesel, the reco#ery of

the methanol, and neutraliation of the glycerol +y4"roduct, along /ith the treatment of the /aste

/ater' Theoretically, under the a""ro"riate conditions of "ressure and tem"erature, in the

"resence of a catalyst, each mole of "alm oil re.uires three moles of methanol to "roduce three

moles of +iodiesel and one mole of undesired glycerol' 6ince the reaction is re#ersi+le, the

for/ard direction is in fa#our to/ard the desired "roduct' The esterification of free fatty acid

(99-! and the acid transesterification reactions here+y tae "lace in one hour /ith /ater and

glycerol as +y4"roduct' -fter discharging the +y4"roducts, the su+se.uent +ase4catalysed

transesterification is done in t/o ste"s' emo#al of glycerol and soa" formation +y manually

"hase se"aration is done +efore "roceeding to the second ste"' -t the end of the last

transesterification, hot /ater (0 >C! at 5 @ (/D/! is introduced gently to the #essel to ca"ture

the remaining glycerol and a #acuum flashing follo/s thereafter to ensure the crude +iodiesel

+eing free of /ater'


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2.+ Contro! sste( roo(

The "ilot "lant in $T%M com"rises of ca"acity at one metric ton (MT! and is o"erated in +atch

mode under a su"er#isory control and data ac.uisition (6C-7-! system' Control room is

defined as a com"onent of com"le system /hich act as a central s"ace /here a large "hysical

facility or "hysically dis"ersed ser#ice can +e monitored and controlled'

m"ortant features of control room include:

i' The control systemii' 6ystem interfaces

iii' Communications

i#' Control room layout#' ndi#idual /orstation design

#i' Control room en#ironment#ii' 6taffingD/orload

#iii' Maintenance

i' Emergency res"onse role

n $T%M +iodiesel "lant, the control room act as a "rimary centre to control the acti#ity inside

the "lant' The "rocess monitoring is done +y control room o"erator' Basically, in control room all

the acti#ities inside the "lant is monitored, order and decision is +eing made in case une"ected

e#ent occurred' The measured "arameters such as flo/, tem"erature, "ressure and le#el are +eing

controlled in the control "anel'

-ccording to -+u %uaifa (student from B "rogramme!, the main o+ecti#e of running

the "lant that day is to remo#e the oil from FE203' The "rocess is +eing controlled +y using

automatic #al#e in the control room' Once automatic #al#e is o"ened, then only the "rocess can

tae "lace inside the "lant' %o/e#er, there are times /hen the acti#ity inside the "lant must +e

done manually such as o"ening the hand #al#e through the order from control room o"erator'

The /hole "rocess is +eing monitored on a com"uter /ith one o"erator mae notes of all theacti#ities and one o"erator communicate /ith "ersons inside the "lant'

2.+.1 UT- Bioiese! "!ant contro! sste(

Control system used: 6ingle cascade system


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Measured "arameters: Tem"erature and control #al#e

hat is Cascae &ste(

Cascade control is mainly used to achie#e fast reection of distur+ance +efore it "ro"agates to the

other "arts of the "lant' The +loc diagram of cascade system can +e sho/n as +elo/:

9igure G: Bloc flo/ diagram of Cascade control system of $T%M Biodiesel &lant

The Cascade Control Bloc 7iagram sho/s a generic cascade control system /ith t/o

controllers, t/o sensors, and one actuator acting on t/o "rocesses in series' - "rimary or master

controller generates a control effort that ser#es as the set "oint for a secondary or sla#e controller'

That controller in turn uses the actuator to a""ly its control effort directly to the secondary"rocess' The secondary "rocess then generates a secondary "rocess #aria+le that ser#es as the

control effort for the "rimary "rocess'

The geometry of this +loc diagram defines an inner loo" in#ol#ing the secondary

controller and an outer loo" in#ol#ing the "rimary controller' The inner loo" functions lie a


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traditional feed+ac control system /ith a set "oint, a "rocess #aria+le, and a controller acting on

a "rocess +y means of an actuator' The outer loo" does the same ece"t that it uses the entire

inner loo" as its actuator'

n the "lant, the "roduct set "oint tem"erature is set on the master ("rimary controller!

control loo"' This is com"ared to the "roduct tem"erature, and the masterHs &7 out"ut is used to

set the remote set "oint of the sla#e (secondary controller!' This is scaled to suit any e"ected

tem"erature' The sla#e loo"Hs natural res"onse time should ideally +e at least 5 times faster than

the master'

9igure *: The control "anel located in the control room' -ll the "arameters to +e measured in the

"lant are controlled from here'


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9igure : The e.ui"ment and acti#ities of the "lant are monitored on a com"uter

9igure


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- steam system consists of a steam4su""ly or generating facility, a steam and condensate return,

/ater "i"ing system, and a steam4use facility' The steam4generating facility, located in the +oiler

room, consists of +oilers, feed/ater systems, heat echangers, +oiler and system controls, fuel

and gas handling e.ui"ment (e'g', fuel trains, stacs!, and steamD/ater treatment e.ui"ment and

"i"ing'

The "ur"ose of the steam4generating facility is to "ro#ide energy in the form of thermal

energy of the steam to dri#e other "rocesses in the steam4use facility' n turn, ty"ical steam4use

facilities are designed to meet #arious industrial and commercial needs such as comfort heating,

food "rocessing, "a"er corrugation, etc'

6team4generating facility design is uni.ue to the s"ecific a""lication and it is dictated +y

good engineering "ractice, a""lica+le national, state, "ro#incial and local codes, and utility and

insurance re.uirements' 6ystem design and selection de"end on o+ s"ecific o"erating

re.uirements, +oiler room structure and #enting, fuel storage, and utility ser#ice considerations'

There is therefore no sim"le mathematical e"ression to correlate steam +oiler room design and

a""lication' %o/e#er, there are se#eral characteristics /hich hel" define the a""lication and its

rele#ant re.uirements'

9or a steam4generating facility, these characteristics include:

i' Ty"e of -""licationDoad

ii' O"erating Conditions, e.uirements and Constraints

iii' 9acility e.uirements and imitationsi#' Codes and 6tandards

#' Other 9ederal, 6tate, &ro#incial and ocal e.uirements

Criteria of the 6team

i' 7etermine the desired o"erating "ressure' 9or eisting steam4use facilities, the o"erating

"ressure has ty"ically +een set in the "ast and no/ acts as a constraint on the system

design at hand' 9or ne/ facilities, slightly more flei+ility eists and yet o"erating

characteristics of e.ui"ment in the steam4use facility either set or limit the range of

o"erating "ressure of the +oiler'


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ii' 7etermine the steam load characteristics and ultimately the "rofile of the steam4use

facility in its entirety (see 6ection 1!' t is im"ortant to understand +oth the steady4state

load "rofile as /ell as the transient and instantaneous demands'

iii' 7etermine the desired or necessary steam .uality (dryness! or degree of su"erheat' 6team

.uality ranges from 0 to 100@ and is defined as the ratio of the amount of saturated

steam #a"or to the total steam amount (/hich may consist of +oth saturated steam #a"or

and li.uid!' - 100@ steam .uality translates to ero amount of saturated steam li.uid and,

in this condition, the steam is termed to +e Idry'J

i#' The degree of su"erheat refers to the amount of thermal energy (heat! added to the steam

relati#e to the saturated steam #a"or "oint of reference, ty"ically e"ressed in units of

degrees 9ahrenheit' 9or eam"le, a degree of su"erheat of 50 >9 means that an additional

amount of heat has +een added to the steam so that the final steam tem"erature is 50 >9

greater than the saturation tem"erature of the steam at the gi#en o"erating "ressure'

2.,.2 &tea( boi!er

9igure 12: 6team Boiler $nit


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6team +oiler /ater systems generate steam for a #ariety of a""lications such as comfort heating,

humidification, steriliation, cooing and many #arious industrial "rocesses' 6team +oilers use

gas, oil or electricity to heat /ater to the "oint of steam generation' 6team is generated at

"ressures ranging from +ars or greater' -s the steam is used it condenses and is either returned

to the +oiler #ia a steam condensate system or is lost as "art of the "rocess (eg' humidification!'

The +oiler selection "rocess is +ased on an e#aluation of the system and load

re.uirements as descri+ed a+o#e, and a com"arison /ith the different +oiler ty"es that are

a#aila+le' The steam4use facility /ill ha#e certain o"erating re.uirements that are used to

esta+lish the +oiler design "ressure' 9or eam"le, heating systems often o"erate at lo/ "ressure

(a steam "ressure of 24; +ar!, and /ould use a +oiler that is designed for +ar' The +oiler design

"ressure must +e higher than the o"erating "ressure, and is usually +ased on common design

"ressures' 6team .uality, or the moisture content in the steam, may also +e a re.uirement of the

facility' Ahen heat is a""lied to /ater containing calcium and +icar+onate ions, the chemical

reaction that taes "lace result in the formation of car+onate ions that ha#e a strong affinity for

calcium' 6cale formation generally consists of calcium car+onate and must +e controlled to

"re#ent loss of heat transfer and localied o#erheating that can result in +oiler tu+e failure' The

greater the steam "ressure, the more critical scale "re#ention +ecomes'

-s heat is a""lied to /ater containing +icar+onate ion and car+onate is formed, car+ondioide gas is also released and is carried out /ith the steam' Ahen the steam condenses the

car+on dioide dissol#es in /ater to form car+onic acid, /hich lo/ers the "% of the returning

condensate and can corrode the steam condensate "i"ing system' This car+onic acid needs to +e

neutralied to "re#ent costly failures due to corrosion and leas in the condensate "i"ing system'

-s steam is generated, the minerals that /ere dissol#ed in the +oiler /ater including sodium,

calcium, magnesium, +icar+onate, chlorides, sulfate and chemical additi#es lie "hos"hate

concentrate' f allo/ed to concentrate uncheced, they /ill e#entually cause foaming, "riming

and +oiler /ater carryo#er into the steam, causing +oiler /ater le#els to +ounce erratically

("ossi+ly causing the +oiler to shut off on lo/4/ater cutout! and introducing +oiler /ater into a

condensate system not designed to handle it' The greater the steam "ressure (and the smaller the

+oiler /ater #olume! the more critical the need to "re#ent ecessi#e dissol#ed solids

concentration'


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The most efficient /ay to "re#ent calcium car+onate scale in the steam +oiler is to

remo#e the calcium through the use of a /ater softener' 6ofteners are al/ays recommended for

steam +oilers regardless of "ressure and the amount of condensate return' t is also "ossi+le to

remo#e the +icar+onate ion that ultimately leads to car+onic acid formation in the steam

condensate through the use of dealaliation or re#erse osmosis' e#erse osmosis is generally

"referred +ecause all dissol#ed solids are reduced, not ust +icar+onate, allo/ing +oilers to

dramatically reduce +lo/do/n and realie the energy sa#ings achie#ed +y not discharging

heated, treated +oiler /ater to the se/er'

2.,.+ Chi!!e 'ater sste(

9igure 13: Chilled Aater 6ystem

Chiller is used to remo#e heat from the /ater /hich is then circulated through other com"onents

to a+sor+ heat from the s"ace' Aater is non4corrosi#e, has s"ecific heat #alue, fluid, non4toic

and is chea"' This maes it an ecellent choice com"ared to other secondary refrigerants such as

sodium chloride +rines, "ro"ylene glycols, ethylene, methanol or glycerin' The chiller is the


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section of the system /here an echange of heat occurred +et/een the /ater that goes to the

+uilding and the e#a"orator' The /ater lea#es the chilled /ater e#a"orator at ;5>9 or *>C' This

chilled4/ater is then circulated through the entire +uilding +y the use of a "um"' The /ater

cooled the s"ace and "ic u" the heat and returns to the chiller at a+out 55>9 or 13>C' The /ater

tem"erature has +een heated u" +y 10>9 or G>C after cooling the s"ace' This "rocess is then

re"eated'

Chilled /ater "lants are com"le systems' 7esign engineers seeing to maimie the

"erformance and economic +enefits of u"graded or ne/ chilled /ater "lants need a thorough

understanding of the maor e.ui"ment used in these "lants' Chilled /ater systems ty"ically tae

on little or no mae4u" /ater the "rimary treatment concern is corrosion' Corrosion in any

system /ill shorten the life of e"ensi#e ca"ital assets and cause "otentially costly "lanto"eration interru"tions or shutdo/ns' Corrosion is caused +y addition of oygen into the system

/ith mae4u" or +y +acteria (anaero+ic! allo/ed to flourish under eisting de"osits' Corrosion

/ill also occur /hen the "% of the system is too lo/ or too high' - common contri+utor to lo/

"% in chilled /ater systems is the degradation of glycol com"ounds used for freee "rotection'

Chilled /ater systems should +e KclosedK to mae4u" addition, +ut if there are /ater losses due

to leas or draining of the system, scale4forming minerals (calcium and +icar+onate! are

introduced into the system and need to +e accounted for +efore de"osition taes "lace' 6cale

formation can significantly affect heat transfer that increases o"erating costs and can also

contri+ute to o"eration interru"tions or shutdo/ns' e/ systems should +e chemically cleaned

"rior to startu" to remo#e oils, greases and other contaminants that naturally enter the system

during construction' 6ystems that ha#e +ecome fouled or are currently e"eriencing corrosion

may also need to +e chemically cleaned'

Many chilled /ater closed systems re.uire freee "rotection /hen coils and other

e.ui"ment are e"osed to the outdoor air tem"eratures of northern climates' Ethylene or

"ro"ylene glycols are ty"ically used' These are not corrosion inhi+itors +ut may +e necessary to

"rotect "lant assets from failure due to freeing' Entire systems may contain glycol, or only coils

e"osed to harsh /intertime conditions' Ahen coil layu" is the a""roach, it is im"ortant to

thoroughly flush the glycol +efore resuming system o"eration to "re#ent the glycol from

degrading to glycolic acid, /hich can lo/er system "% and accelerate corrosion'


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2.,., 3ir Co()ressor

9igure 1;: -ir Com"ressor

The chiller is the section of the system /here an echange of heat occurred +et/een the /ater

that goes to the +uilding and the e#a"orator' The /ater lea#es the chilled /ater e#a"orator at

;5>9 or *>C' This chilled4/ater is then circulated through the entire +uilding +y the use of a

"um"' The /ater cooled the s"ace and "ic u" the heat and returns to the chiller at a+out 55>9 or

13>C' The /ater tem"erature has +een heated u" +y 10>9 or G>C after cooling the s"ace' This

"rocess is then re"eated'

t is /orth noting that the running cost of a com"ressed air system is far higher than the

cost of a com"ressor itself' Energy sa#ings from system im"ro#ements can range from 20 to 50

"ercent or more of electricity consum"tion, resulting in thousands to hundreds of thousands of

dollars' - "ro"erly managed com"ressed air system can sa#e energy, reduce maintenance,

decrease do/ntime, increase "roduction through"ut, and im"ro#e "roduct .uality'


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Com"ressed air systems consist of a su""ly side, /hich includes com"ressors and air

treatment, and a demand side, /hich includes distri+ution and storage systems and end 4use

e.ui"ment' - "ro"erly managed su""ly side /ill result in clean, dry, sta+le air +eing deli#ered at

the a""ro"riate "ressure in a de"enda+le, cost4effecti#e manner' - "ro"erly managed demand

side minimies /asted air and uses com"ressed air for a""ro"riate a""lications' m"ro#ing and

maintaining "ea com"ressed air system "erformance re.uires addressing +oth the su""ly and

demand sides of the system and ho/ the t/o interact'

Main Com"onents of Com"ressed -ir 6ystems:

Com"ressed air systems consist of follo/ing maor com"onents: ntae air filters, inter4stage

coolers, after4coolers, air4dryers, moisture drain tra"s, recei#ers, "i"ing net/or, filters,

regulators and lu+ricators (see 9igure 3!'

i' ntae -ir 9ilters: &re#ent dust from entering a com"ressor 7ust causes sticing #al#es,

scoured cylinders, ecessi#e /ear etc'

ii' nter4stage Coolers: educe the tem"erature of the air +efore it enters the net stage to

reduce the /or of com"ression and increase efficiency' They are normally /ater4cooled'iii' -fter4Coolers: The o+ecti#e is to remo#e the moisture in the air +y reducing the

tem"erature in a /ater4cooled heat echanger'i#' -ir4dryers: The remaining traces of moisture after after4cooler are remo#ed using air dryers,

as air for instrument and "neumatic e.ui"ment has to +e relati#ely free of any moisture' The

moisture is remo#ed +y using adsor+ents lie silica gel Dacti#ated car+on, or refrigerant

dryers, or heat of com"ression dryers'


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-s the name suggests, the flo/ of /ater is at right angles to the flo/ of air' The cooling to/er for

this ty"e of design is usually sha"ed lie a +o' Aarm /ater is "um"ed to the to" of the cooling

to/er /here it is distri+uted to the sides and allo/ed to dro" through small holes' &lastic air

intae lou#ers at the sides of the cooling to/er allo/ the /ater to s"read out /hile dro""ing' -ir

from the outside is suced into the cooling to/er +y se#eral fans located at the to"' The incoming

air comes into contact /ith the dro""ing /ater, and the latter is cooled' The cooled /ater is

collected at the +ottom of cooling to/er' This /ater is then "um"ed out again and circulated

through the chiller' The heat from the chiller is transferred to it again' The /arm /ater then

returns +ac to the to" of the cooling to/er and the cycle starts again'

ii' Counter 9lo/

Counter flo/ cooling to/ers ha#e the air "assage flo/ing directly against the flo/ of the /ater'

-s /ith the cross flo/ design, /ater is allo/ed to s"read out /ith the hel" of air inlet lou#ers'

Their +ottle lie sha"e characteries this ty"e of cooling to/ers' There is only one single fan at

the centre' 9itted +elo/ the fan is a rotating /ater "i"e distri+utor' The "i"es of the /ater

distri+utor shoot /ater only from one side' The action of the /ater "ressure shooting from one

side rotates the distri+utor' The /ater is thus dro""ed e#enly o#er the air inlet lou#ers' The /ater

dro""ing +y gra#ity meets head on /ith the u" mo#ing air current suced in +y the fan' The air

cools the /ater' The /ater collected at the +ottom of the cooling to/er is "um"ed to the chiller,

+ecomes heated u" again, and is then returned +ac to the cooling to/er for cooling' n cooling

to/ers, the cooling effect is achie#ed +y e#a"oration of a "ortion of the /ater "assing through it'

-s the /ater is e#a"orated, im"urities remain in the recirculating /ater' The concentration of the

dissol#ed solids increases ra"idly and can reach unacce"ta+le le#els' n addition, air+orne

im"urities are often introduced into the /ater' f the contaminants are not controlled, they can

cause scaling, corrosion, and sludge accumulations /hich can reduce heat transfer efficiencies'

n order to control the concentrations, it is necessary to +leed a small amount of circulating /ater

from the system and to" u" /ith fresh /ater' f the site conditions are such that constant +leed4

off /ill not control scale or corrosion, chemical treatment is necessary' E#en /ith +leed4off or

chemical treatment, it is still necessary to control +iological contamination' The gro/th of algae,

and other microorganisms can reduce system efficiency and may e#en contri+ute to "otentially

health haards' Biocides are used to treat the /ater to control the +iological gro/ths' Oone is


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+oth /idely no/n and "ro#en effecti#e at limiting and eliminating +iological gro/th, such as

algae' The most logical and rele#ant /ay to use oone /ithin the +io4fuels industry /ould +e in

the cooling to/ers' Oone can +e incor"orated into an eisting system /ith minimal system

modifications' Often, cooling to/er /ater is treated /ith disinfectants such as chlorine and

+romine, /hich are consuma+le and can +e costly' Oone can effecti#ely reduce, if not eliminate,

the need for these consuma+le chemicals /ithin the cooling /ater loo"' Oone can +e inected

directly into the cooling to/er or it can +e inected into the influent stream' f any +iological

gro/th is "resent u"on installation of an oone system, the initial oone demand /ill +e higher

than actually needed during continuous use' 6ince oone is not +iased, it /ill oidie metals,

ru++er, and "lastics if a+le to' This is a maor concern and also e"lains the need for /hy the

le#els of oone in a system should +e monitored at all time' Oone generation is an emerging

technology that can +e #ery useful and also cost4effecti#e if it is utilied correctly and res"ected

for +eing a "o/erful oidier'

2.,.4 C"O storage tank

9igure 1G: C&O storage tan


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The most suita+le sha"e is the #ertical circular cross4section tan /ith self4su""orting fied roof,

"refera+ly con#e in sha"e' Ahere "ossi+le, tall, narro/ tans are "referred, to minimie

e"osed surface areas' Tan +ottoms should +e conical or slo"ed to +e self4draining' 9or each

installation, the storage ca"acity needs to +e related to the e"ected storage "eriod, the rate of

turno#er and the num+er of different "roducts to +e handled'

The tans /as not made +y co""er, +rass or +rone as any "art of the storage installation and

means of trans"ort that has contact /ith the oils, such as "i"ing, "i"e connections, #al#es,

heating coils, tem"erature gauges for oil, strainers, "um", etc' or in sam"ling a""aratus' Lauges

containing mercury should not +e used' The material used for the construction of tans is inert to

oils and fats' The tans /all, floor and roof are coated /ith fi+erglass or 31G stainless steel'

The tan /as installed /ith heating facilities in order to o+tain homogenous "roducts

/hen they are transferred or unloaded' %eating coils are +e of mild steel for mild steel tans and

of stainless steel for coated and stainless steel tanage' The tan are insulated in tem"erature and

cold climate' nsulation is fitted eternally to the /all of the tan and /as design to a#oid the

a+sor"tion of oil or /ater' Oil .uality is "reser#ed and energy is sa#ed' The storage tan also

installed /ith tem"erature sensor and automatic control de#ices to "re#ent o#er4heating of oil in

the tan' The thermometer /as carefully "laced and a/ay from the heating coils'

i'ong term storage ( 2 /ees!

ong term storage should +e maintained at am+ient tem"erature and heating should +e

com"letely turned off' f the oil +ecomes solid, etreme care should +e taen during the initial

heating to ensure that localied o#erheating or "ressure +uild4u" does not occur'

ii' 6hort term storage (N 2 /ees!

To "re#ent ecessi#e crystalliation, the oil should +e maintained /ithin the tem"erature range of

5410 C a+o#e melting "oint' The deterioration of oil .uality cannot +e sto""ed com"letely' Ae

can only use certain "recautionary ste"s to minimie deterioration'

2.,.5 aste 'ater treat(ent sste(


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9igure 1*: Aaste /ater treatment tan

Most +iodiesel manufacturing "rocesses result in the generation of "rocess /aste/aters /ith free

fatty acids and glycerine (i'e' soa"y /ater!' Other constituents in the +iodiesel manufacturing

"rocess /aste/ater include organic residues such as esters, soa"s, inorganic acids and salts,

traces of methanol, and residuals from "rocess /ater softening and treatment'

6ources of /aste/ater include /ash /ater /hich is used to remo#e any soa"s formed

during the transesterification reaction steam condensate "rocess /ater softening and treatment

to eliminate calcium and magnesium salts, iron, and co""er and /aste/aters from the glycerine

refining "rocess' The ty"ical +iodiesel manufacturing /aste/ater has high concentrations of

con#entional "ollutants, i'e' +iochemical oygen demand (BO7!, total sus"ended solids (T66!,

oil and grease, and /ill also contain a #ariety of non4con#entional "ollutants'

Common "re4treatment "rograms sho/ a range of BO7 concentrations from ;,500 u" to

3*,000 mgD' e#els of con#entional "ollutants in the ra/ /aste/ater are liely to +e affected +ythe manufacturing efficiencies (e'g', "oor reco#ery of glycerine and methanol /ill result in high

BO7 concentrations in the ra/ /aste/ater!' n contrast, the BO7 and T66 concentrations for

ty"ical domestic /aste/aters range from 110 to ;00 mgDl and 100 to 350 mgDl, res"ecti#ely'

2.,.6 Bio!ogica! treat(ent 73erobic8


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Biodiesel (B4100! is a Class 4B li.uid /ith a flash "oint around 2GG>9' E#en though Biodiesel

itself is relati#ely safe for use and storage, careful consideration and safety "recautions must +e

taen in its manufacture' -ll electrical systems and e.ui"ment /ithin storage, transfer, and

"rocessing areas need to +e re#ie/ed to ensure that they are rated for haardous areas' Many

fires ha#e +een started +ecause the /rong ty"e of electrical e.ui"ment /as used'

-ll facilities are re.uired to ha#e +asic fire and life safety measures:

i' 49ire etinguishers

ii' 46"rinlers or 6u""ression systems (for indoor o"erations!iii' 4Clear and uno+structed egress from "rocessingDstorage areas

9ollo/ing local, state and federal regulations, Biodiesel &lant $T%M has im"lemented:

i' - high4ca"acity, /ater4deluge +uilding s"rinler system designed to "rotect the entire

"rocessing area'

ii' - +uilding #entilation system designed to dra/ fresh4air across the entire "rocessing area'

iii' - foam fire su""ression system designed to "rotect the methanol truc unloading and

tan4farm area'

i#' - hard/ired safety4instrumented4system'

#' Electrical and electronic de#ices suita+le for use in haardous areas'

-dditional "rocess "rotection measures include on4going o"erator training and a ro+ust "rocess

control system designed to assist o"erators in maintaining the safe and efficient "roduction of

+iodiesel'


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Ahen an increase of the "roduction rate is desired, the alcohol feed rate is firstly increased,

follo/ed +y the acid' Ahen a decrease of the "roduction rate is desired, the acid rate is the first

one to +e reduced' The .uality control structure is sho/n in 9igure 20'

9igure 20: Control system ensuring that during transient "eriod the acid is ne#er in access

,.0 CONC


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References

-nderson, 7', Masterson, 7', Mcdonald, B', 6ulli#an, ' (2003!' Biodiesel &lant 7esign and

Engineering: &ractical E"erience, 1=10'

Bildea, 6orin, C', Piss, -leandru, -' (2010!' Control 6trategies for a Biodiesel &rocess +y

eacti#e -+sor"tion, 21, 123*=12;2' htt":DDdoi'orgD10'3303DCET102120*

ational &roducti#ity Council, ndia' Com"ressors' n: Technology Menu for Efficient Energy

$se, Motor 7ri#e 6ystems (&C!' 1

Documents

Biodiesel Pilot Plat