Defnition o the project A TSP (Triple Super phosphate) plant needs to be design in such as a way to achieve a production production of of 97200 T! of TSP" #$000 T! phosphoric acid and $20 000 T! of sulphuric acid%
Basic data: Location o the project: &t is located on the ban' of the river arnaphuli at which is about '* fro* +hittagong Airport , $2'* to the south of +hittagong +ity% This location is in Patenga Patenga &ndustrial Area having co**unication facilities by rail" road , river%
Product Name: $% Main Product: TSP fertili-er fertili -er%% 2% Intermediate Products: Sulfuric Acid" Phosphoric Acid% By-Product/ ypsu*% .% By-Product/
The overall plant consists o: •
•
•
•
1arious plants such as the Sulphuric acid plant" Phosphoric acid plant" eaction plant" etc%
3etty for raw raw *aterial unloading unloading facility% facility%
aw *aterial storage capacity%
4ater treat*ent plant as an au5iliary plant and certain other facilities%
$
Plant Process: Name of Plant
Name of Process used in plant
Sulphuric Acid Plant
onsanto +ontact Process
Phosphoric Acid Plant
6issan (e*i 8iydrate)
eaction Plant
8en Process
ranulation Plant
Sta*i +arbon
actory !rea "!cre#:
$% Plant site
.7%2#
2% y ypsu* :eld
$$%9;
.% o ousing area
$<%<9
% 3etty , ad=oining area
9%90
#% >thers
%<9
to total
80.51
Main $a% materials and source: Raw materials
Source
oc' Sulphur
&ra?" &ran" +anada" orocco" Saudi Arabia" Poland%
oc' Phosphate
3ordan" orocco" Algeria" Syria%
Phosphoric Acid
Tunisia" Poland" &ran" orocco" &ndia%
@?ypt"
+hina"
2
Process description The process ow in each of the plants involved in the pro=ect pro=ect is described as follows/
&!T'$ T$'!TM'NT PL!NT "!u(iliary plant# The industry re?uires re?uires a large a*ount of water supply for the various proce processe sses% s%
There Therefor fore" e" a water water treat* treat*ent ent plant plant is present present there there with with
capaci capacity ty of 20#0 20#0 tBday tBday%% 4ater ater fro* fro* arn arnofu ofuli li river river is collec collected ted if the chloride ion concentration is within a *a5i*u* allowable a*ount of 2#0 pp*% pp*% &n dry dry seas season ons" s" when when the the sali salini nity ty of rive riverr wate waterr is very very high high"" alternate sources of water are used (either underground water or water fro* 4ASA)% 4ASA)% 4ater collected collecte d in reservoir is brought by pu*p to treat*ent plant%
The following take take place at the treatment plant: plant:
4ater pu*ped to
clarifer (here" alu* and caustic added)
clear water )))))
passed to
flter ed
+lear water
*
+
,
.
+
(esidue out) Cilter water (used for
+ sanitary and drin'ing
purposes" etc%)
Deminerali.er (cation and anion e5chan er
* (8e*i water out)
Important points:
•
Alu* is given for coagulation and caustic is added to *aintain p for better coagulation%
•
&ons such as calciu* ions" *agnesiu* ions" sodiu* ions" sulphate
ions" phosphate
ions" etc%
are
re*oved in the
de*inerali-er% Silica is also re*oved here (Silica test is done in every ; hours to ensure de*iwater purity i%e% to test if resin regeneration re?uired or not)% •
8e*i water is very i*portant for use in the plant to prevent corrosion of e?uip*ent parts (say for e5a*ple" boiler tubes are very e5pensive and longlasting so they should be saved fro* corrosion)%
The equipments involed in the water treatment plant:
•
Reservoir:
4ater is collected in .#0 t reservoirs during low tide period when a*ount of salts in water is low% 4ater contains about 2#0 pp* chloride ion is preferable% Sedi*entation occurs here% Sedi*ented water is transferred to another tan' having sa*e capacity% Cour centrifugal pu*ps at inta'e station near =etty are used for water transport% •
lari!er:
4ater is clari:ed by coagulation" oaculation and settling in clari:er% Alu* is used to coagulate and 6a> is used to *aintain p here% Cro* clari:er water goes to clari:ed water tan'% Two lines are connected to clari:ed water tan' one goes to cooling water tan' and other goes to clean water tan'% •
lean water tank:
+lari:ed water is sent to clean water tan'% &t is used as reservoir%
•
"ilter #ed:
A *ain portion of clear water is sent to :lter bed by pu*ping for :ltration% Cilter bed is co*posed of anthracite" co'e and grave% •
"iltered water tank:
4ater which passes through the :lter bed is reserved in :ltered water tan'% 4ater goes to the sanitary water line" process water line and ion e5changers% •
ation and anion $%changer:
#
To re*ove cation and anion fro* water" one cation and two anion e5changer bed are used in water treat*ent plant% +ation e5changer bed wor's based on wea' base and anion e5changer bed wor's on strong base% egeneration of cation e5changer bed is done by 2S> and regeneration of anion e5changer bed is done by 6a> solution%
&eminerali'ed (ater storage: The water which is free fro* ion is de*inerali-ed water% This 'ind of water is obtained fro* ion e5changer beds and stored% Cro* here it is passed to boiler% •
ooling water tank:
&n the cooling water tan'" water co*es fro* the +lari:er% This tan' is connected to the SA&& plant" PA&& plant" TSP and granulation plant%
/ses o the di0erent types o %ater in the industry: 1. )ses of process water: •
&n ranulation and bagging plants%
•
&n washing the :lter ca'e%
•
&n air co*pressor in SA&& plant%
•
&n recovered water tan' in PA&& plant%
•
&n *ill vent dust collector in the *illing plant%
*. )ses of &emi water: •
&n the boiler%
•
Cor dilution acid in SA&& and PA&& plant%
•
Cor laboratory purposes%
<
+. )ses of wash water: •
Cor scrubbing in the PA&& plant%
•
&n ypsu* slurry tan'%
,. )se of -anitar water: %
Sanitary water is used in the housing colony%
MILLIN1 PL!NT Cor the purpose of unifor* *i5ing and unifor* reaction in the plants" it is very i*portant for the particle si-e of reactants to be unifor* at a re?uired value% &n this plant 200n* si-e of particle of roc' phosphate is produced which is used for *anufacturing TSP fertili-er , phosphoric acid% The roc' phophate which is i*ported is nonunifor* in si-e and therefore it *ust go through the *illing plant in order to be processed to the re?uired unifor* si-e%
(orking principle of the plant: •
•
•
Cor grinding roc' phosphate" at :rst stored roc' phosphate is charged into charging hopper fro* store roo*% Then these roc' phosphate are weighed by the roc' weigher and sent to roc' feeder through buc'et elevator% oc' feeder is used to feed roc' phosphate into the ball *ill% Dall *ill consists of four types of balls of diEerent si-es F 0**" #0**" <0**" 70** *ade of cast iron" *ild steel" stainless steel% ot air , roc' phosphate are charged into rotating ball *ill where roc' phosphate is ground into desired si-e (200n*) , *oisture is also re*oved fro* it% The ball *ill of this plant is rotated at $;rp*% The balls ha**er the roc' phosphate turning it to re?uired for* and wind pressure forces it upwards%
7
•
Outlet of ball mill is sent to mill classifier, where over size (>200nm) rock phosphate is separated from desired size. Over size rock phosphate is recycled into ball mill throuh rock feeder and desired size rock phosphate is sent in round rock cyclone. !n round rock cyclone more separation of oversize rock phosphate is occurred.
•
Only desired size of rock phosphate is sent in rock hopper from rock cyclone. "nd this rock phosphate is used to manufacturin #$% in #$% plant & phosphoric acid in %" plant.
2/LP3/$I4 !4ID PL!NT Cor TSP *anufacture in the reaction plant" phoshoric acid is a raw *aterial and to produce this phosphoric acid" sulphuric acid is re?uired% The *ain raw *aterial for producing sulphuric acid is roc' sulfur% This Sulphur is i*ported and then analysed properly% The co*plete analysis re?uires about 7 days%
Raw material analsis: component Sulphur oisture Ash content >rganic *atter
amount 99%#G *ini*u* 0%#G *a5i*u* very less within a re?uired a*ount
$quipments involed in the process: Melter
;
The powdered sulphur is initially *elted in the *elter to ta'e it into a suitable for* for the following reaction% The *elting point of sulphur is around $$.$$#H+ so a te*perature of around $.0$.#0+ is *aintained in the *elter% The *elter consists of three units" na*ely" the charging cha*ber" settling cha*ber and the pu*ping cha*ber% At :rst roc' sulfur is charged to the charging cha*ber% Around .0.$ stea* coils present in the *elter supply the re?uired heat for *elting% Then the *olten sulfur is sent to settling cha*ber where i*purity re*oval ta'es place through settling (a :lter should have been in action here to re*ove i*purity but the :lter is currently out of order)% elatively pure *olten sulfur is ta'en as overow fro* this cha*ber to the pu*ping cha*ber% Cro* the pu*ping cha*ber" *olten sulphur is tranported to the furnace by a pu*p% There are two pu*ps in action of which any one is used%
))) ))) 2ettlin Pumpin 9 9 chame chame r to furnace) r sent
Sulphur) 4har9in (olten sulphur 9
chame r
)
))
urnace &n this part of the process" *olten sulphur is burned in dry air to for* sulphur dio5ide at a te*perature range of about 900$0000+% olten sulfur fro* the *elter is sprayed into the furnace by a pu*p , two sulphur guns% Cresh air fro* the drying tower is charged into the furnace% The following reaction ta'es place/ 2
5
67
8
267
>wing to the e5other*ic nature of the reaction" heat is evoled% The outlet gas is passed to the waste heat boiler%
9
&aste heat oiler The waste heat boiler is a shell and tube heat e5changer in which the heat in the outlet gas fro* the furnace is reduced to a re?uired level for the ne5t stage% At the sa*e ti*e" this heat is utili-ed in stea* for*ation% Doiler reduced gas te*perature fro* $0000+ to around 000+% This heat is ta'en by 8e*i water used in the boiler to tranfor* into stea* which is re?uired at various parts of the plant% &t is sent to the phosphoric acid plant which is dependent on this stea*%
1as flter The i*purities present in the furnace outlet are re*oved in the gas :lter% as :lter consists of crushed :re bric' that reduce the a*ount of catalyst re?uired , increase the life of catalyst% &*purities increase the pressure drop , decrease the conversion eIciency% Thereofre it beco*es vital to :lter the* out%
4onverter +onverter is one of the *a=or parts of this plant% ere" S> 2 is converted to S>. in presence of the catalyst 1J>K% The converter consists of diEerent beds for better conversion% The beds have diEerent volu*e" diEerent a*ounts of catalyst" pressure" etc% Te*perature variation *ay occur in the diEerent beds but the overall converter te*perature re*ains :5ed at about .00+% &n :rst and second beds" gas is leaving at elevated te*peratures so to *aintain an ade?uate level of te*perature cold fresh air is passed through the converter% This air co*es fro* drying tower% &n the third bed" the gas ow is passed into a heat e5changer" where S>2 , S>. given in shell side and cold fresh air passed in tube side% The following reaction ta'es place at the converter/ 267
5
67
8
26;
$0
The *ain purpose of the two econo*i-ers used in this plant is to reduce the te*perature level of the gas strea* to an appropriate inlet te*perature for the absorbing tower% 8e*i water fro* water treat*ent plant is used as the cooling *ediu*% >utput hot water (*ainly stea*) is sent to waste heat boiler section% The gas strea* fro* the converter enters $st econo*i-er at a te*perature of .00+ and leaves at 2.00+% The 2nd econo*i-er further reduces the te*perature to $700+ which is the re?uired inlet te*perature for the absorbtion tower%
!sorin9 to%er The gas strea* fro* the 2nd econo*i-er at $700+ is passed to the AT tower (absorbing tower)% AT tower is one 'ind of pac'ed bed that consists of reaching rings through which S>L passes and therefore better *i5ing and reaction ti*e possible% This gas is passed at the lower end of the tower and fro* the top end of the tower" 9;%#G 2S> is passed% This is done as we 'now S>L cannot be absorbed directly into water% +ounter current ow ta'es place% 9;%#G 2S> is circulated continuously and the reaction produces 99%9G 2S>% The stac' gas is sent to the at*osphere and the product strea* is passed to 8%T pu*p tan'%
!=T pump tan> ? D=T pump tan> Dotto* product of absorption tower is sent to A%T pu*p tan'" where it is *i5ed with 8% water to evolve heat% ot sulphuric acid in A%T pu*p tan' is sent to A%T cooler by A%T pu*p to recover heat% After recovery one part of product is sent to storage tan' , other part is sent directly to absorption tower% Another part of product fro* A%T cooler is sent to 8%T pu*p tan'% Then 9;%#G 2S> in 8%T pu*p tan' is sent to 8%T cooler where this acid releases *ore heat% The outlet of 8%T cooler is sent to the top of the drying tower% The product fro* the drying tower is sent to 8%T pu*p tan'% So a cycle is *aintained with A%T pu*p tan' by sending a portion of strea* leaving 8%T cooler% +onductivity *eter used in AT pu*p to *aintain p%
Dryin9 to%er 8rying tower is a scrubber% 9;%#G 2S> is sent to the tower" where 2 S> is spray the top of the drying tower , air passed through the botto* of the tower% Air is sent to the drying tower fro* at*osphere by blower ,
$$
turbine% &n this section fresh air is produced" where 9;%#G 2S> absorbs *oisture fro* air% Then this fresh air is sent to furnace for producing gas% 8ilute sulphuric acid is sent to 8%T tan'%
)ses of sulphuric acid: •
&n TSP plant%
•
&n Phosphoric acid plant%
•
&n 4ater treat*ent plant%
•
&n &ron industry%
•
&n Maboratory%
•
&n diEerent types of food industries%
P362P36$I4 !4ID PL!NT Phosphoric acid is an inter*ediate poduct of the industry% &t is considered a raw *aterial for the TSP *anufacturing process% A part of it is i*ported fro* foreign countries and a part is *ade in the plant% The *a=or reaction in the plant is/ 4a@"P6A# 5 ;326A 5C36 ) 73@P6A 5 ; 4a26A=736 The ypsu* produced in this reaction (*oisture 20G" purity 909#G) is a byproduct but currently it has a very high de*and in the *ar'et% &t costs 000 ta'a per ton and therefore plays a very i*portant role in the industryNs pro:t%
/rocess outline: !cid cooler 9;%#G Sulphuric acid and dilution water are *i5ed and the heat generated is tranferred to cooling water in the dilution cooler% After cooling " the te*perature of the dilute acid is usually about 70;0G% The ow rate of the cooling water is regulated by a valve and controlled by the diluted 2S> te*perature recording controller%
$2
Premi(er oc' phosphate passing fro* 70G pass 200 *eshes (200 *esh *eans 200 holes per inch)" 7#G2S> fro* dilution cooler and phosphoric acid (20G P2>#) are fed to the pre*i5er% Acid enters at <0H+ and roc' phosphate enters at #0<0H+% eation starts and around ##G reaction ta'es place in the pre*i5er% A te*perature of about 9;H+ is *aintained in the pre*i5er%
Di9ester The pre*i5er outlet is fed to the digester for further reaction% oughly a te*perature of around <7H+ is *aintained in the pre*i5er% There are two digesters% Ti*e" te*perature and agitation are *aintained in the digesters for proper reaction% Around ;0;#G of the reaction is co*pleted here%
4rystalli.er The *a=or diIculty in the phosphoric acid plant is the crystal production and seperation of soild and li?uid part% To enhance crystal for*ation" there are . crystalli-ers with a relative decrease in their te*perature levels having te*peratures of #;H+" #7H+ and ##H+ respectively% Slurry proceeding for* the deco*position stage" containing he*ihydrate of +aS> is recrystalli-ed and thereby hydrated to fro* gypsu*% The slurry deco*posed phosphate roc' is introduced into the three crystalli-ers% 6ear the point of entry" the slurry is *i5ed with the seed recycled fro* the crystalli-er% Proper agitation and settling ti*e *aintained in the crystalli-ers so that about 9;G of reaction is co*pleted at the end of the .rd crystalli-er% &t ta'es about $< hrs (reaction ti*e) for the slurry to cross the whole area%
ilter
$.
Slurry fro* the crystalli-er containing fully *atured crystals in rho*bic for* is pu*ped to rotary vacuu* :lter through slurry distributor% ere the product acid is separated as the :ltrate and gypsu* is obtained as :lter ca'e which is byproduct and thrown into the pond in the gypsu* yard% $st :ltrate (.0GP2>#) is obtained in the :rst stage of :lter and pu*ped to the :ltrate holding tan' by vacuu* pu*p% $st washing/ . rd :ltrate is used to washout the slurry and the :ltrate obtained is recycled bac' to the pre*i5er as return acid% 2nd washing/ 8 water is used to washout the slurry and the :ltrate obtained is for $st washing% The :lter is a tilting type :lter consisting of $; pans% Osing special technology" every drop of acid is :ltered% The pans are in continuous *otion and vacuu* :ltration occurs throughout the *otion which seperates the solid and li?uid part%
4oncentrator The product acid of .0G P2># is then concentrated to #0G P2># acid in a concentrator (calendria) by heating the *aterial with stea* under forced vacuu* circulation syste*% This is done because #0G P2># is re?uired to produce TSP of the re?uired #% Mow pressure stea* is used in the shell side where phpsphoric acid is passed through tube side% ere two stage e=ectors are used with baro*etric condenser to create vacuu* in the evaporation section% The evaporator is 'ept half :lled for the purpose of evaporation% The e?uip*ents here are *ade of graphite tube which is appropriate for phosphoric acid handling% #0G P20# content PA is sent to TSP plant% About $.#T of phosphoric acid is produced per day%
)ses of /hosphoric acid: Since it is a raw *aterial for TSP production and a huge a*ount of it is re?uired at the reaction plant" the entire phosphoric acid is used for the *anufacture of TSP%
)ses of psum:
$
•
&n fertili-ers
•
As an additive in ce*ent
•
&n 4all board
•
&n Plaster products
$'!4TI6N PL!NT "T2P PL!NT# So far we have discussed about the plants which process raw *aterials or produce the inter*ediate products which are re?uired for the *ain purpose of the industry which is TSP *anufacture% Triple super phosphate (TSP) is the *ain product of TSP co*ple5 Mtd% TSP is *anufactured by deco*position of roc' phosphate ground to the :neness of ;0G pass through 200 Tyler *esh in an air swept Dall ill" with phosphoric acid (#0G P2>#) in a eaction 8en under standard conditions of te*perature , ow rate% The den product is 'nown as reen TSP which re?uires further processing% The following reaction ta'es place at the reaction plant/ 4a; "P6#7 5 3;P6 5 ;376);4a"37P6#7=376
utline of the /rocess: Cor TSP production" ground roc' phosphate and phosphoric acid" .P> (#0G P2>#) are re?uired% The raw *aterials are fed to the eaction 8en where the reaction ta'es around 20 *in% The outlet is reen TSP which is i**ature TSP% Cor the re*aining #$0G reaction" this TSP is sent to the curing houseQ where it is 'ept for few days for reaction co*pletion%
$quipments involved in the plant: Buc>et elevator &t is a vertical type of conveyor used in TSP plant to elevate the ground roc' fro* ground roc' phosphate storage house to ground roc' bin%
$#
1round roc> in round roc' phosphate fro* roc' grinding plant is fed to ground roc' bin through buc'et elevator via screw conveyor% An inclined screw type conveyor is used to charge ground roc' phosphate to cone *i5ture fro* roc' bin%
Dilution cooler 9;G 2S> is produced in sulphuric acid plant but to produce TSP fertili-er only 70G 2S> is re?uired% Therefore" 9;G 2S> is diluted by *i5ing 8% water (*aintaining 2S> , 8% water ratio) in dilution cooler% 8ilute 2S> (70G 2S>) is stored in storage tan'% Cro* this tan' 70G 2S> is fed to cone *i5er for producing TSP fertili-er%
4one mi(er +one *i5er contains a si*ple cone bo5 in which ground roc' phosphate fro* ground roc' bin , 70G 2S> fro* , #0G phosphoric acid fro* PA plant are fed% +one *i5er *i5es the entire co*pound unifor*ly , the *i5er is charged into continuous den%
4ontinuous den eaction *i5ture fro* the cone *i5ture is dropped to the continuous den consisting of a conveyor belt upon which the product dries , proceeds towards the outlet% The retention ti*e of den is 20 *inutes and there is a rotary cutter which slices the product and the belt conveyor transports the product to the curing house before it is sent to the granulation plant% Onreacted roc' phosphate , so*e gas produced in continuous den containing roc' phosphate is fed to scrubber% Cro* scrubber" recycled roc' phosphate is fed to cone *i5er%
1$!N/L!TI6N PL!NT
$<
The cured TSP fro* the curing house is ta'en to the granulation plant% ranulation is a process by which granular TSP is produced fro* powder TSP% &n this ranulation plant" $.%.** si-e of TSP fertili-er is produced through the Sta*icarbon process% The capacity of this ranulation plant is #00 tonBday% Cor reducing waste" this plant needs to be inactive for hours in a day% The plant consists of a dru*li'e granulator% ere" granules are for*ed through the principle of agglo*eration with stea* and process water%
2dvantage of granular form over powder form: educes the loss of fertili-er when it used in land (for e5a*ple" powder for* is easily carried away by wind) % Certili-er stays in land for longer periods of ti*e% @nviron*ental pollution is also reduced%
(orking principle of the ranulator: reen TSP which is produced in TSP plant is fed to the granulator by using conveyor belt , buc'et elevator via a weighing device% Cine particles of TSP which are separated fro* over and standard si-e TSP fertili-er are also recycled to a granulator via a weighing device% Process water and low pressure stea* is also fed to granulator unifor*ly by *aintaining the proper solid li?uid ratio for satisfactory granulation% 8iEerent si-e (under si-e" standard si-e" over si-e) of granular TSP for*s in this section% 1apor fro* granular is re*oved , sent to scrubber" to prevent bloc'ing of the line by dust , water vapor% A sprayer is installed in the vapor line% Cinally granular TSP which is with a speci:cation of
ther $quipments involved in the plant: urnace At*ospheric air is blown through an air blower to the furnace for being heated% eat is produced by burning natural gas in the furnace% Cor *aintaining the outlet te*perature (#00+) of the furnace a bypass line of at*ospheric air is connected% eated air is sent to dryer for drying the granular TSP%
$7
$otary drum dryer The TSP obtained fro* the granulator outlet contains $2G *oisture which is above the re?uired TSP speci:cations% Therefore" to reduce this *oisture content fro* $2G to #G (re?uired content)" rotary dru* dryer is operated% ranular TSP containing $2G *oisture is fed to rotary dru* dryer where hot air (te*p% #00 +) is also fed unifor*ly% Dy rotating action of the rotary dru* dryer the granular TSP co*es in contact with hot air in a cocurrent ow% 8ue to this" *oisture content of TSP is reduced to #G% The outlet te*perature of air is ;00+% &t is very i*portant to note that the process in the granulation plant is an ArtQ F if" due to any reason" the *oisture content in the green TSP is altered" reaction conditions *ust be ad=usted such that a *a5i*u* of #G *oisture content is obtained in the :nal TSP product%
Buc>et elevator A buc'et elevator is used for transporting TSP fro* rotary dru* dryer to coarse screen (it is also re?uired for the transport of the green TSP fro* conveyor belt to granulator)%
4oarse screen >utlet fro* the rotary dru* dryer is fed to coarse screen by a buc'et elevator via a conveyor belt for separating over (.**) , under ($**) si-e granular TSP fro* standard si-e ($.%.**) TSP% over si-e is then sent in crusher , standard , under si-e TSP sent in :ne screen%
4rusher >ver si-e granular TSP is fed to crusher where it is crushed into desired si-e of TSP% Then crushed TSP is sent bac' to coarse screen%
ine screen Onder si-e TSP is separated fro* standard si-e TSP in :ne screen section% Standard si-e TSP is sent in bagging plant and under si-e TSP is sent bac' in granulator%
$;
B!11IN1 PL!NT Cor the purpose of sending the :nal product to the *ar'et" TSP fertili-er fro* granulation plant is sent to the bagging section through the conveyor belt and buc'et elevator% &n this section" TSP is charged into a hopper where a *easuring device is used to *easure the weight of TSP fertili-er% #0'g of TSP fertili-er is charged in every bag% After bagging these are sent to storage house via conveyor belt% The bag consists of a layer of polythene inside and a layer of polypropylene outside% The capacity of this bagging plant is bagging of TSP $<$; bagB*in% The :nal product Fgranular TSP has the following co*position/
omposition of T-/ fertili'er: omponent
2mount
oisture content
#G a5i*u*
Total P2>#
<%0G ini*u*
4 P2># (water soluble P2># )
0%0G ini*u*
C P2># (free P2>#)
.%0G a5i*u*
Si-e
Desi9n Basis To produce 97200 etric ton per year (T!) granular TSP of $ F .%.** si-es%
Process Bloc> Dia9ram
$9
3illing /lant ( :ne ones pass out)
U
B!LL MILL ( wind ta'es away the
(oc' phosphate grinded by balls)
ground roc' phosphate) 4L!22II'$
W
VVVVV
(non
unifor* ones recycled)
-ulphuric 2cid /lant M'LT'$ (stea* SulphurVadded to *elt sulphur)
VVV
/$N!4 ' (dry air added)
46NE'$T'$ VVVV (dry air added) S>JRZ>JVS>L in resence of
W W
!T T6&'$ JS>X (sulphuric acidYYY added)
/hosphoric 2cid /lant 20
P!N P$'MI VV '$
VV
VV
DI1'2T '$
ILT' $
4$G2T!LLI H'$
46N4'NT$! TI6N VV /NIT
Reaction /lant
46N'
))) 46NTIN/6/2 D'N
MI'$
V) reen TSP
F F (recycled roc'
phosphate)
* F F 24$/BB' $
F
Process lo% Dia9ram 2$
Material Balance or 2ulphuric !cid Plant: To 8esign 00 T8 ($20 000 T!) capacity sulphuric acid plant / ( how to calculate Dac' cal%)
00 T8 [ $<<<<%<7 'gBhr of acid (considering .00 days a year plant is running)
4ith 9;%#G purity" the acid per hour [ (0%9;\$<<<<%<7) 'gBhr [ $<...%. 'gBhr
*olBhr of Sulphuric acid to be produced [ ($<...%. B9;) [$<<%<7 '*olBhr
Absorption of the acid is $00G
Therefore" S>. [ $<<%<7 '*olBhr "26; 5 376 8 37 26#
>verall conversion of S>2 to S>. in reactor is 99%;G "267 8 26;#
5
67
Then S>2 re?uired is ($<<%<7B0%99;) '*olBhr [ $<7 '*olBhr
Cor $00G co*bustion of Sulphur
"2
5
67
8
267 #
A*ount of *olten sulphur re?uired [ $<7 '*olBhr [ ($<7 \ .2) 'gBhr [ #. 'gBhr
22
This sulphur has purity of 99%#G" therefore the re?uired rate of solid sulfur to *ellter [ (#. B 0%99#) 'gBhr [ J;K=J >9hr A*ount of o5ygen re?uired to convert $ '*ol sulphur to S>. [ $%# '*ol "2 5 <=J67 826;#
Then" a*ount of o5ygen re?uired [ ($<7\$%#) '*olBhr [ 2#0%# '*olBhr Osing 20G e5cess air" >2 re?uired [ (2#0%#\$%2) '*olBhr [.00%< '*olBhr)
Therefore" dry air in [ (.00%<\$00)B2$ [ $.$%. '*olBhr
Total weight of dry air [ ($.$%.\29) '*olBhr [
>molhr
or Phosphoric !cid Plant: To 8esign $70 T8 (#$000 T!) capacity phosphoric acid plant /
$70 T8 [ 70;.%.. 'gBhr (considering .00 days a year plant is running)
70;.%.. 'gBhr .P> [ (70;.%..B9;) '*olBhr [ 72%. '*olBhr
Cro* reaction stoichio*etry it is found that/ 2 '*ol .P> is produced fro* . '*ol 2S> "4a@"P6A# 5 ;326A 5C36
) 73@P6A 5 ; 4a26A=736#
72%. .P> '*olBhr is produced fro* (.B2 \ 72%.) '*olBhr [ $0;%# '*olBhr 2S>
Cor ;#G conversion occuring in this plant/ e?uired 2S> [ ($0;%# B 0%;#) '*olBhr [ $27%< '*olBhr
2.
This is ;0 G 2S> (diluted)" therefore / ;0 G 2S> consists of $27%< '*olBhr/ Then 9;%# G 2S> consists of (9;%#B;0 \ $27%<) '*olBhr [ $#7%$ '*olBhr [ ($#7%$\9;) 'gBhr
[ 9hr Cro* reaction stoichio*etry "4a@"P6A# 5 ;326A 5C36 ) 73@P6A 5 ;4a26A=736# : . '*ol 2S> reacts with $ '*ol roc' phosphate" Then $27%< '*olBhr 2S> reacts with ($B. \ $27%<) '*olBhr [ 2%#.. '*olBhr roc' phosphate Therefore" re?uired weight of roc' phosphate [ (2%#.. \.$0) 'gBhr [
<;<J=7; >9hr Cor $27%< '*olB hr" water re?uired [ (2\$27%<) '*olBhr [ 2##%2 '*olBhr [ (2##%2 \ $;) 'gBhr [ JO;=C >9hr Cor ypsu* production/ "4a@"P6A# 5 ;326A 5C36 ) 73@P6A 5 ; 4a26A=736# . '*ol 2S> reacts to produce . '*ol gypsu*" Then" $27%< '*olBhr 2S> reacts to produce $27%< '*olBhr gypsu*
2
[ ($27%< \ $72) 'gBhr [ 7
>9hr 9ypsum produced
or $eaction Plant "T2P Plant#: To 8esign .2 T8 (97200 T!) capacity TSP plant / 4a; "P6#7 5 3;P6 5 ;376);4a"37P6#7=376
"T2P# .2 T8 [ $.#00 'gBhr TSP (ta'ing .00 days of a year)
Cro* stoichio*etry it is observed that . '*ol TSP is produced fro* $ '*ol roc' phosphate" This *eans" 7#< 'gBhr TSP fro* .$0 'gBhr 'g roc'
phosphate" Therefore" $.#00 'gBhr TSP fro* (.$0B7#< \ $.#00) 'gBhr [ JJ;J=K
>9hr roc> phosphate
To produce 7#< 'gBhr TSP" .92 'gBhr .P> re?uired Therefore" $.#00 'gBhr TSP fro* (.92B7#< \ $.#00) 'gBhr [ K >9hr
3;P6 reuired
Also" to produce 7#< 'gBhr TSP" # 'gBhr 2> re?uired (fro* stoichio*etry) Therefore" $.#00 'gBhr TSP fro* (#B7#< \ $.#00) 'gBhr
2#
[ 9<%. >9hr
376 reuired
'ner9y Balance
'uipment List For
Sulphuric Acid Plant
elter Curnace 4aste heat boiler as :lter +onverter $st and 2nd @cono*i-ers AT Tower 8rying tower Pu*p 8ilution +ooler
2<
For
Phosphoric Acid Plant
Acid cooler (8ilution cooler) Pre*i5er 8igester +rystalli-er Cilter Pu*p +oncentrator
For
TSP Plant
+one *i5er +ontinuous den Scrubber
For
Granulation Plant
ranulator Curnace otary dru* dryer Duc'et elevator +oarse screen +rusher Cine screen
'uipment Desi9n 27
P ? I Dia9ram
Plant Layout
2;
'stimation o Total 4apital Investment ? Production 4ost: i(ed-capital investment: 4omponent
4osts "Ta>a#
Percenta 9e 6 T4I
&irect costs Purchased @?uip*ent
22;900;00
0G
Purchased @?uip*ent installation
#72<0000
$0G
&nstru*entation , controls
..7<000
Piping
#79<;000
;G
@lectrical
2;<2.0000
#G
Duildings
$7$7.;000
.G
$$92000
2G
Service facilities
#79<;000
;G
Mand
#72<000
$G
!ard i*prove*ents
Total direct costs
JJ<<
Indirect costs @ngineering , supervision
..7<000
+onstruction e5pense
22;9;000
G
+ontractorNs fee
$$92000
2G
+ontingency
2;<2.0000
#G
Total indirect costs Total f(ed-capital investment "T4I#
OK;<7
JK7C Ta>a
29
So" Total f(ed-capital investment 8 JK7C Ta>a
/roduction 4ost:
&irect /roduction cost : $a% material costs:
4omponent $oc> 2ulphur $oc> Phosphate
!mount "MTG#
Price per MT
4osts "Ta>aG#
.;<70
7000
270<90000
$.790%<9<
$0000
$.790<9<0
Total
6peratin9 Laour 4osts: >perating Mabour +osts/ .00000000 Ta'a
/tilities:
The +ost of Otilities [ 29<<0000 Ta'a
Maintenance and $epairs: The aintenance and epair +ost [ $00000000 Ta'a
eneral $%penses:
!dministrative costs: .0
The Ad*inistrative costs [ 0000000 Ta'a
$esearch and Development costs:
The esearch and develop*ent costs [ #0000000 Ta'a
Distriution and 2ellin9 4osts:
The 8istribution and selling costs [ $00000000 Ta'a
Local Ta(es: .G of the total :5ed capital invest*ent So" Mocal Ta5es [ $7$7.;000 Ta'a
Insurance: &nsurance costs [ #0000000 Ta'a 6ther costs: +osts [ 200000000
Total production ost 4 **,,60 Taka
Total capital investments 8 total f(ed-capital cost 5 Total production ost 8 COJOOC Ta>a
Total income from selling /roduct: Selling price of 1MT TSP = !!! Ta"a Selling price of 1MT #S$% = 1&!!! Ta"a .$
Selling price of 1MT G'psum = (!!! Ta"a
7ame of product
2mount 3T9
Income Taka;9
T-/ fertili'er
)(!!
1*+%!!!!!
-ulphuric 2cid
,(&!-*
1!1&%&!!
psum
1&+!1)-+%
11!,1*+++!
Total .from selling product/
++,5<++80Ta ka;9
'conomic !nalysis: 1ross Income 8 Total income Q total production cost [ ..#79..;0 F 292999<0 [ 2079;20 Ta'a
Ta(es 8
Net Proft 8 S1ross income Q Ta(es [ 2079;20 F <.$$97<. [ .#7<7;<#7
.2
$ate o $eturn 8 SNet proftU<RTotal 4apital Investment [ .#7<7;<#7 ]$00GB ;<9#99<0 [ %$.#2G
3!H6P !nalysis A 3!H6P analysis is a procedure for the syste*atic" critical" e5a*ination of the operability of a process% Techni?ues considered are/ (a) Cailure *odes and eEects analysis ("3$2. (b) Cailure *odes" eEects and criticality analysis ("3$2. (c) a-ard and operability studies (=2>/. (d) @vent tree analysis ($T2. (e) Cault tree analysis ("T2. (f) Probabilistic ha-ard analysis A A^>P analysis should be carefully e5a*ined for any plant with a large nu*ber of e?uip*ents which *ay have ris's of ha-ards% S*ooth operation can be done by prevention of possible accidents% Met us ta'e the sulphuric acid plant for e5a*ple and study the A^>P analysis on it for enhanced safety%
3!H6P !nalysis o 2ulphuric acid plant:
A^>P Analysis of Melter/
uid e wor
&eviati on
auses
onsequences
2ctions
..
d •
6o
Te*p%
•
•
•
Mess
Te*p% •
ore
Mevel
Mess stea* Partially supply of S Partial da*age of *elter
*elting epair *elter
sulphur eplace pu*p Cully or Mi?uid Partially failure Mevel increase in , high level of pu*p *elter alar* in *elter%
A^>P Analysis of pump/
uid &eviat e ion word
6o
Clow
Mess Clow
ever se
6o stea* ow oc' sulphur(S) >pening to the *elter does not *elt stea* supply elter da*age line valve
Mevel
auses
Cully failure pu*p
onsequences
of
>verow sulphur
of
2ctions
li?uid eplace pu*p , high level alar* in *elter
Partially failure Mess ow of li?uid epair or of pu*p , sulphur to the replace pu*p bloc'age in pipe Curnace , ratio controller adding in Curnace Cully or Partially Mi?uid sulphur eplace pu*p failure of pu*p owing bac' to the , place non *elter return control valve
A^>P Analysis of urnace/
.
1uid e %or d
Deviati on
4auses
•
•
Mow
Te*p
•
•
ore
Te*p%
•
•
ore
Clow
educing Pressure Moss of eating Caulty &nstru*entatio n and +ontrol eaction +ontrol Cailures eater +ontrol Cailure Caulty &nstru*entatio n and +ontrol
atio controller *isoperation
4onseuences
•
•
S>2 co*bustion will not occur
esulting in inco*plete co*bustion and possible after burning and a*e i*pinge*ent on tubes
igher percentage of air , gas content" increase Curnace te*perature
!ctions
•
•
•
&ncrease the te*perat ure up to desired level% Procedure s to li*it fuel :ring to air availabilit y Auto*ati c heater shutdown
eplace or repair ratio controller
A^>P Analysis of 1as ilter:
uid e wor d
&eviatio n
Clow Mess
As well as
co*positi on
auses
onsequences
2ctions
Partially bloc'ed S>2 gas canNt epair :lter passes s*oothly Cilter , separation does not occur as our re?uir*ent
as
Cully da*age of 1arious i*purities epair gas :lter goes to +onverter replace Cilter
or as
.#
A^>P Analysis of 4onverter/
uid e wor d
6o
&eviati on
Clow
ore
Clow
auses
atio failure
Te*p%
•
2ctions
Cully da*age of 6o ow to the epair +onverter @cono*i-er replace +onverter
•
Mess
onsequences
or
controller @5cess air eplace or consu*ed in the repair ratio +onverter controller ,reduce te*p%
Mess air supply >utlet due to partially reduces opening of air supply line valve Partial da*age of +onverter
te*p% Cully opening air supply line 1alve
A^>P Analysis of 'conomi.er/
uide word
&eviati on
auses
onsequence s
2ctions
.<
igh
Pressure
•
•
•
•
igh
Te*pera ture
•
•
•
Couled or Cailed @5changer Tubes +ooling 8%% 4ater Cailure Caulty &nstru*entati on and +ontrol
ther*al e5pansionBcont raction between tubes and shell resulting in tube lea'Brupture
•
•
Moss of *echanical integrity of tube @5ternal :re
•
•
•
•
Procedural control of introduction of process uids on startup and shutdown Periodic inspection
igh te*peratur e indication with alar* epair necessary e?uip*ent
A^>P Analysis of !sorin9 To%er/
uide word
&eviati on
Mess
ow
auses
•
•
igh
Surge Proble*s &nade?uate 1olu*e of 1ents &ncorrect 1ent Set Pressure for 1ents Cailed >pen P+1
Clow
• •
•
&f S>. is not available fro* 2nd econo*i-er 9;%#G 2S>is not available fro* drying tower% +ontrol Caults reater Cluid 8ensity +ross +onnection of
onsequence s
2ctions
+ontact process for the production of sulphuric acid is ha*pered% Mess production +reate a high pressure
>perator action in response to low ow indication
•
•
igh speed alar* and overow shutdown
.7
Syste*s
syste*
.;