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Index
Sr. No. Topics Page No.
1 Introduction 1
2 Physiochemical Properties/ Uses 2
3 List of all Manufacturing processes 6
4 Detail flow Sheet / Manufacturing Process 7
5 Material Balance 9
6 Energy Balance 21
7 Design of Equipment 33
8 Instrumentation & Process control 50
9 Plant Location & Plant layout 51
10 Safety & Environment 53
11 Material Data Safety Sheet 56
12 Cost Estimation 58
13 Manufacturing Industries 63
14 Conclusion 64
15 References 65
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Chapter 1: Introduction
Phenol, also known as carbolic acid, is a toxic, white crystalline solid with a sweet tarry odor, commonly referred to as a "hospital smell". Its chemical formula is C6H5O H and its structure is that of a hydroxyl group (-OH) bonded to a phenyl ring; it is thus an aromatic compound.
Phenols are similar to alcohols but form stronger hydrogen bonds. Thus, they are more soluble in water than are alcohols and have higher boiling points. Phenols occur either as colorless liquids or white solids at room temperature and may be highly toxic and caustic.
Phenols are widely used in household products and as intermediates for industrial synthesis. For example, phenol itself is used (in low concentrations) as a disinfectant in household cleaners and in mouthwash. Phenol may have been the first surgical antiseptic. In 1865 the British surgeon Joseph Lister used phenol as an antiseptic to sterilize his operating field. With phenol used in this manner, the mortality rate from surgical amputations fell from 45 to 15 percent in Lister’s ward. Phenol is quite toxic, however, and concentrated solutions cause severe but painless burns of the skin and mucous membranes. Less-toxic phenols, such as n-hexylresorcinol, have supplanted phenol itself in cough drops and other antiseptic applications. Butylated hydroxytoluene (BHT) has a much lower toxicity and is a common antioxidant in foods.
In industry, phenol is used as a starting material to make plastics, explosives such as picric acid, and drugs such as aspirin. The common phenol hydroquinone is the component of photographic developer that reduces exposed silver bromide crystals to black metallic silver. Other substituted phenols are used in the dye industry to make intensely colored azo dyes. Mixtures of phenols (especially the cresols) are used as components in wood preservatives such as creosote.
Phenols are common in nature; examples include tyrosine, one of the standard amino acids found in most proteins; epinephrine (adrenaline), a stimulant hormone produced by the adrenal medulla; serotonin, a neurotransmitter in the brain; and urushiol, an irritant secreted by poison ivy to prevent animals from eating its leaves. Many of the more complex phenols used as flavorings and aromas are obtained from essential oils of plants. For example, vanillin, the principal flavoring in vanilla, is isolated from vanilla beans, and methyl salicylate, which has a characteristic minty taste and odour, is isolated from wintergreen. Other phenols obtained from plants include thymol, isolated from thyme, and eugenol, isolated from cloves.
Chapter 2: Physiochemical Properties
1. Molecular weight: 94.11
2. Boiling point (at 760 mm Hg): 181.7 degrees C (359.1 degrees F)
3. Specific gravity (water = 1): 1.07 at 20 degrees C (68 degrees F)
4. Vapor density: 3.24
5. Melting point: 43 degrees C (109.4 degrees F)
6. Vapor pressure at 35 degrees C (77 degrees F): 0.35 mm Hg
7. Solubility: Soluble in water (8.3 g/100 ml) and benzene; very soluble in alcohol, chloroform, ether, glycerol, carbon disulfide, petrolatum, volatile and fixed oils, and aqueous alkali hydroxides; almost insoluble in petroleum ether.
Flammability
The National Fire Protection Association has assigned a flammability rating of 2 (moderate fire hazard) to phenol.
2. Auto ignition temperature: 715 degrees C (1319 degrees F)
3. Flammable limits in air (percent by volume): Lower, 1,7; upper, 8.6
4. Extinguisher: For small fires use dry chemical, water spray, or regular foam. Use water spray, fog, or regular foam to fight large fires involving phenol.
Although phenols are often considered simply as aromatic alcohols, they do have somewhat different properties. The most obvious difference is the enhanced acidity of phenols. Phenols are not as acidic as carboxylic acids, but they are much more acidic than aliphatic alcohols, and they are more acidic than water. Unlike simple alcohols, most phenols are completely deprotonated by sodium hydroxide (NaOH).
Oxidation:
Like other alcohols, phenols undergo oxidation, but they give different types of products from those seen with aliphatic alcohols. For example, chromic acid oxidizes most phenols to conjugated 1,4-diketones called quinones. In the presence of oxygen in the air, many phenols slowly oxidize to give dark mixtures containing quinones.
Hydroquinone (1, 4-benzenediol) is a particularly easy compound to oxidize, because it has two hydroxyl groups in the proper relationship to give up hydrogen atoms to form a quinone. Hydroquinone is used in developing photographic film by reducing activated (exposed to light) silver bromide (AgBr) to black metallic silver (Ag↓). Unexposed grains of silver bromide react more slowly than the exposed grains.
Phenols are highly reactive toward electrophilic aromatic substitution, because the nonbonding electrons on oxygen stabilize the intermediate cation. This stabilization is most effective for attack at the ortho or para position of the ring; therefore, the hydroxyl group of a phenol is considered to be activating (i.e., its presence causes the aromatic ring to be more reactive than benzene) and ortho- or para-directing.
Picric acid (2, 4, 6-trinitrophenol) is an important explosive that was used in World War I. An effective explosive needs a high proportion of oxidizing groups such as nitro groups. Nitro groups are strongly deactivating (i.e., make the aromatic ring less reactive), however, and it is often difficult to add a second or third nitro group to an aromatic compound. Three nitro groups are more easily substituted onto phenol, because the strong activation of the hydroxyl group helps to counteract the deactivation of the first and second nitro groups.
Phenoxide ions, generated by treating a phenol with sodium hydroxide, are so strongly activated that they undergo electrophilic aromatic substitution even with very weak electrophiles such as carbon dioxide (CO2). This reaction is used commercially to make salicylic acid for conversion to aspirin and methyl salicylate.
Phenolic resins account for a large portion of phenol production. Under the trade name Bakelite, a phenol-formaldehyde resin was one of the earliest plastics, invented by American industrial chemist Leo Baekeland and patented in 1909. Phenol-formaldehyde resins are inexpensive, heat-resistant, and waterproof, though somewhat brittle. The polymerization of phenol with formaldehyde involves electrophilic aromatic substitution at the ortho and para positions of phenol (probably somewhat randomly), followed by cross-linking of the polymeric chains.
Uses
- Phenol finds extensive use in the production of phenol formaldehyde resin which is a thermoset
- It is used in industrial and decorative laminates, molding molds, textile auxiliaries and varnishes.
- Both acetone and phenol are condensed in the presence of a catalyst to produce bisphenol-A whish is used in the manufacture of epoxy resins, polycarbonate resins, polyester resins rubber chemicals and fungicides.
- Phenol has a sweet odour that is detectable at 0.06 PPM, which enables it to be used in an air freshener.
- Phenol is also a powerful disinfectant and bacteria killer.
- In industry, phenol is used as a starting material to make plastics, explosives such as picric acid, and drugs such as aspirin.
- The common phenol hydroquinone is the component of photographic developer that reduces exposed silver bromide crystals to black metallic silver.
- Other substituted phenols are used in the dye industry to make intensely colored azo dyes
Chapter 3: List of all Manufacturing Process
Small quantities of phenol are isolated from tars and coking plant water produced in the coking of hard coal and the low temperature carbonization of brown coal as well as from the wastewater from cracking plants.
By far the greatest proportion is obtained by oxidation of benzene or toluene. Although direct oxidation of benzene is in possible, the phenol formed is immediately oxidized further.
Therefore, alternative routes must be chosen, e.g. via halogen compounds which are subsequently hydrolyzed or via cumene hydroperoxide which is then cleaved catalytically.
The following process was developed as industrial synthesis for production of phenol.
1. Alkylation of benzene with propene to isopropyl benzene (cumene), oxidation of cumene to the corresponding tert-hydroperoxide, and cleavage to phenol and acetone (Hock process).
2. Toluene Oxidation to benzoic acid and subsequent oxidizing decarboxylation to phenol ( Dow process )
3. Sulfonation of Benzene and production of phenol by heating the benzene sulfonate in moltan alkali hydroxide.
4. Chlorination of benzene and alkali hydrolysis of the chlorobenzene.
5. Chlorination of Benzene and steam hydrolysis of the chlorobenzene ( Rasching process, Rasching – Hocoker, Gulf oxychlorination)
6. Dehydrogenation of Cyclohexanol – cyclohexanone Mixtures ( Scientific Design)
Justification for the selected process:-
Of the processes named, only the Hock process (cumene oxidation) and the toluene oxidation is important industrially. The other processes were given up for economic reasons. In the Hock process acetone is formed as byproduct.
This has not, however, hindered the expansion of this process; because there is a market for acetone .New plants are now run predominantly on the cumene process.
Chapter 4: Description of selected process
Cumene Process:-
The Cumene – phenol process is based on the discovery of cumene hydeoperoxide and its cleavage to phenol and acetone published in 1944 by H. hock and S.Lang. This reaction was developed into an industrial process shortly after World War II by Distilliers Co. in the United Kingdom and the Hercules Powder Co. in the United States.
Process:-The raw material for the product phenol i.e. cumene is obtained by alkylation of Benzene with propene using phosphoric acid or aluminium chloride as catalyst.
Two reaction steps form the basis of the production of phenol from cumene.1. Oxidation of cumene with oxygen to cumene hydroperoxide:
2. Cleavage of cumene hydroperoxide in an acidic medium to Phenol and Acetone.
Oxidation:-The oxidation of cumene with air or oxygen – enriched air is carried out in S.S. (304) reactors R1 & R2 which work on bubble column principal. The reactors are connected in cascade series to achieve an optimal residence time distribution. The oxidation is
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performed at 90-130 ºC and 0.5 – 0.7 Mpa. It is carried out in an aqueous emulsion stabilized by an alkali such as sodium carbonate in the 8.5 -10.5 pH range. The waste gas from the reactor is purified by two stage condensation of organic impurities, which consist predominanatly of cumene. Water is used as coolant in the first stage and refrigerant in the second stage.
The oxidation is autocatalytic, i.e. the reaction rate increases with increasing hydroperoxide concentration. The reaction is exothermic; ca. 800KJ are released per kilogram of cumene hydroperoxide. The heat of reaction is removed by cooling.
Cleavage:-
The acid-catalyzed cleavage of cumene hydroperoxide to phenol and acetone follows an ionic mechanism. Sulfuric acid is used exclusively as the catalyst in industry. The acid-catalyzed cleavage is carried out in homogeneous phase in which an excess of acetone is charged to the cleavage reactor and 10-12% sulfuric acid is added. The reaction temperature is the boiling points of the cumene hydroperoxide – acetone mixture i.e. 50-60 ºC. The heat removal from the strongly exothermic reaction (ca. 1680 KJ per kilogram of cumene hydroperoxide) is achieved by means of evaporation of acetone from the reaction system.
Separation:-
The first distillation column is a multicomponent one in which acetone is obtained as a top product and the bottom products are sulfuric acid, phenol, water. The next distillation column is operated under vacuum in which the top product is the waste water and bottom product is mainly phenol associated with sulfuric acid. In the next section which is a simple separator the phenol is obtained as top product and sulfuric acid as bottom product.
Phenol is obtained with a purity of > 99.9% by subsequent distillation.
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Chapter 5: Material BalanceBasis: - 1 t/h of cumene in feed. 24 t/d of cumene.
Let cumene in air-vapor mixture- 8%
Air/cumene= 92/8= 11.5 Let volume ratio= Mole ratio (assuming ideal gas mixture)Mole ratio=11.5
As per stoichiometric rxn:
Cumene + oxygen Cumene hydroperoxide
Therefore, O2/Cumene = 1 and Air/Cumene = 1/0.21 = 4.762
M.W. of air = 28.84 kg/kmol M.W. of cumene = 120 kg/kmol; So, % excess of air/O2 used = (11.50 – 4.762) / 4.762 = 141.5%
Now,Stream 6 will contain O2, N2, vapour of cumene & cumene hydroperoxide.
O2 in stream 6 = O2 in stream 3 – O2 consumed in 1st converter.
In 1st converter conversion based on cumene is 17%; Therefore, cumene consumed in 1st reactor = 8.33 * 0.17 = 1.4161 kmol/hO2 consumed in 1st reacter = 1.4161 kmol/h (as per stoichiometry)
Cumene in stream 11 = cumene in 9 – Nc = 0.9152 – 0.06532 = 0.84988
Yc = Nc / Nt =0.06532 / 30.055 = 0.00217 Xc = 1
Hence major amount of vapour are condensed in C.W. condenser. So, the revision in values of stream Xi is not required.
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Im stream 12, let the brine be the cooling medium in the next condenser to recover remaining cumene vapour, temp = 5º C Pvc = 1 mm HgPt = Po2 + Pn2 + ∑ PviXi6 * 760 = Po2 + Pn2 + 1 * 1 + 1 * 0
Cuemen in stream 10 = unconverted cumene in 2nd reactor = 6.9 – 0.6664 – 0.006596 = 6.227 kmol /h
Cumene hydroperoxide in stream 10 = cumene hydroperoxide formed in 2nd reactor = 2.0825
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F = D + W = 6.2275 + 2.0825 = 8.3095 kmol /h
F * Zf = D * Xd + W * Xw8.3095 * 0.75 = D * 0.999 + W * 0.0000633
Therefore, W = 2.0713 kmol /h (nearly pure cumene) D = 6.238 kmol/h (cumene)
The heat removal from the strongly exothermic cleavage reaction (ca. 1680 KJ / Kg ) of cumene hydroperoxide is achieved by means of evaporation of acetone from the reaction system.[1,2]
W = 2.076 kmol/h * 152 kg/kmol = 315.552 kg/h
Therefore, heat released in cumene hydroperoxide = 1680 * 315.552 = 530127.26 KJ/hλ acetone = 145 cal / gm = 606.39 kj /kgTc acetone = 235 T = 50 º C Tc- T = 185 º C Evaporation rate of acetone in reactor = 530127.26 / 606.39 = 874.2349 kg/h
Cumene hydroperoxide a high boiling point component (n.b.p. is 246.6 º C)
Vapour pressure of water at 50 º C is 92.51 mm Hg.Partial pressure of water vapour in vapour mixture = v.p. * liquid mole fraction = 92.51 * Xw
H2SO4 (catalyst) = 10% of 315.552 = 31.55 kg /hAs per the stoichiometry of the reaction the no. of moles of cumene hydroperoxide is same as that of phenol and acetone formed.
The energy balance of a particular system can be achieved from the first law of thermodynamics which states that total energy of an isolated system remain constant. The first law of thermodynamics relates to the conservation of energy of energy.
Now let’s take equipment one by one and make energy balance each around.Energy balance around 1st rector :-
The reaction is exothermic; ca 800 KJ are released per kilogram of cumene hydroperoxide.
Equation:-
Rate of energy in with feed stream (1 & 3) + Heat generated by reaction = Heat removed in overhead condenser + rate of energy out with product stream + heat removed in external heat exchanger.
Let the temp. of feed streams (1 & 3) and let the reference temp. For this energy balance is 25 ºC.
Enthalpy of feed stream = 0.
Heat generation by rxn = ∆ Hr in KJ/Kg * Kg/h of product formed = 800 * (1.416 * 152) = 172185.6 KJ/h
Heat duty of cooling water overhead condenser = qci = ∑ miλi mc = 2.14493 kmol/h = 257.3916 kg/h mcup = 0.01228 kmol/h = 1.86656 kg/h
Latent heat of cumene = 330 KJ/kg
Since cumene hydroperoxide is a similar compound its latent heat = 330 KJ/kg
Freezing point = 96.03 ºCBoiling point = 152.39 ºCDensity, g/cm30 ºC 0.878620 ºC 0.8619 40 ºC 0.8450
Heat of vaporization at b.p. = 312J/gHeat of vaporization at 25 ºC = 367J/gHeat of formation at 25 ºC = -41300 J/molHeat of combustion at constant pressure & 25 ºC Gross = 43400 J/g Net = 41200 J/g
Almost an organic peroxides are photo and thermally sensitive because of the facile cleavage of the weak oxygen – oxygen bond; ∆H = -125.6 to -184.2 kJ / mol (i.e. -30 to -44 Kcal / mol)
Rate of energy in with feed stream (1 & 3) + Heat generated by rection = Heat removed in overhead condenser + rate of energy out with product stream + heat removed in external heta exchanger.
Circulation rate required of reaction mass in reactor1 , for rise in reaction temp 1 ºCTherefore, mc clc ∆t = 8598.64 KJ/hmc = 8598.64 / (1.642 * 1) = 5236.6869
ms λs = 8598.64 ms = 8598.64 / 2201.6 = 3.905 kg /h
Rate of energy in with feed stream (5) + Heat generated by reactor = Heat removed in overhead condenser + rate of energy out with product stream + heat removed in external heta exchanger.
Rate of energy in with stream (5) = Hr(5) = 127858.5 KJ/kg
Heat generated in reation = ∆ Hr in KJ/kg * kg/h of product formed = 800 * 101.2928 = 81034.24
At t = 182.02 λs = 2005.9ms = 399569.0791 / 2005.9 = 199.195 kg/h
The heat removal from the strongly exothermic cleavage reaction (ca. 1680 KJ/kg i.e. 0.011053 KJ/kmol of cumene hydroperoxide) is achieved by means of evaporation of acetone from the reaction system.
Enthalpy of feed stream + heat of dilution of sulfuric acid + enthalpy of liquid stream + energy evolved due to rxn = enthalpy of liquid product stream + gas stream leaving from the top + heat removed in C.W. circulated.
Heat of dilution of sulfuric acid = - 4 KJ/ mol H2SO4 = 4000 * 0.3219 = 1287.6 KJ/h
Heat duty of feed stream = m Cp ∆t = 2.076 * 205 * (150 - 25) = 53197.5 KJ/h
Enthalpy evolved due to the reaction ∆ Hr = 1680 KJ/kg * 315.552 Kg /h = 530127.36 KJ/h
According to energy balance eqn :-38302.2 + 14895.3 + 530127.36 + 12198.4896 + 28214.3651 = 633205.66 + 160167.1672 + Heat removed in external circulated water.
∆ Hr = - 169635.1125 KJ/h = ms λs
At 110ºC λs of steam is 2226.2 KJ/kg , ms = 169635.1125 / 2226.2 = 76.1994 kg/h
In this case rxn is not highly exothermic & it is necessary to remove all the acetone formed during the rexn by vaporization to maintain the rxn temp.
Across Scrubber:-
Heat of the feed + Heat released in acetone formed = Heat required in condenser + Heat of product stream. 160167.1672 + 35.082 = Qc + 40412.8547Qc = 119789.3949 KJ/h
At avg temp = 104ºC = 377 K , determine αTopmost temp = 58ºC & Bottommost temp = 150ºC
ln P = A – B / (T+C)
Component A B C
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Acetone Light Key 14.7171 2975.95 -34.5228 Phenol 15.2767 4027.98 -76.7014 Water Heavy Key 16.5362 3985.44 -38.9974
Since the conc. of H2SO4 is negligible so it will not create any influence on the vapour pressure of water.ln Pacetone = 14.7171 – 2975.95 / (377 - 345228) Pacetone = 414.7185 KPa.
Vo = m / ρlav = 5122.6345 / 921.7775 = 5.5573 m3 / h = 0.09262 m3 / min
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Γ = V / Vo V = 0.09262 * 15 = 1.3893 m3
Let, H/D = 1 where H= Depth of liq. In reactor shell in meter & D = Inside diameter of vessel
Let the type of bottom head = Torisherical
Inside volume of torisperical head, V= 0.084672 Di 3 + π / 4 Di 2 Sf
Where Di = Inside diameter of reactor,mV = Inside volume, m3
Sf = straight flange, m
Vworking = π / 4 Di 2 h + 0.084672 Di 3 + π / 4 Di 2 Sf
Let Sf= 1.5 in. = 0.0381 m & H/D = 1
1.3893 = π /4 Di3+ 0.084672 Di 3 + π / 4 Di 2 Sf
On solving the above eq. we get Di = 1.5624 m
H = D = 1.5624 m
Consider provision of 20% extra space for vapour – liquid disengagement then actual height of shell of reactor is H = 1.87488m
Energy balance across reactor:-
The heat removal from the strongly exothermic cleavage reaction (ca. 1680 KJ/kg i.e. 0.011053 KJ/kmol of cumene hydroperoxide) is achieved by means of evaporation of acetone from the reaction system.
Enthalpy of feed stream + heat of dilution of sulfuric acid + enthalpy of liquid stream + energy evolved due to rxn = enthalpy of liquid product stream + gas stream leaving from the top + heat removed in C.W. circulated.
Heat of dilution of sulfuric acid = - 4 KJ/ mol H2SO4 = 4000 * 0.3219 = 1287.6 KJ/h
Heat duty of feed stream = m Cp ∆t = 2.076 * 205 * (150 - 25) = 53197.5 KJ/h
Enthalpy evolved due to the reaction ∆ Hr = 1680 KJ/kg * 315.552 Kg /h = 530127.36 KJ/h
According to energy balance eqn :-38302.2 + 14895.3 + 530127.36 + 12198.4896 + 28214.3651 = 633205.66 + 160167.1672 + Heat removed in external circulated water.
∆ Hr = - 169635.1125 KJ/h = ms λs
At 110ºC λs of steam is 2226.2 KJ/kg , ms = 169635.1125 / 2226.2 = 76.1994 kg/h
In this case rxn is not highly exothermic & it is necessary to remove all the acetone formed during the rexn by vaporization to maintain the rxn temp.Now, μacetone at 60 ºC = 0.6 mPa.sμcum. hyp. at 60 ºC = 2.8 mPa.s μs.a. at 60 ºC = 3.1mPa.sμwater at 60 ºC = 0.5 mPa.s
It is difficult to find the suitable correlation for the reaction mass side heat transfer coefficient as the reaction is taking place. hi ca be governed by boiling coefficient or by convective film coefficient. If flat blade 45º C turbine agitator is used to improve the reaction rate and to improve the convective film heat transfer coefficient, thenhi = hnb or hic whichever is less.hic = convective film coefficient, W/(m2 * ºC)hnb = nucleate boiling coefficient, W/(m2 * ºC)
To calculate the convective film coefficient hic, let the tip velocity of turbine agitator V = 200 m / min = π * Da * n ,
where Da = Diameter of agitator n = Rotational spped of agitator in revolutions per min.
Putting the above values we get, 1 / Uo = 0.00085188 Uo = 1173.8698 W / m ºC
Heat duty φt = 47.1209 * 1000 J/sec or W ΔTm = 35 ºC
Heat transfer area required A = φt / (Uo * ΔTm ) = 47120.9 / ( 1173.8698 * 35 )
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= 1.1469 m 2
Outside heat transfer area provided with 75% height covered jacket Ao av. = 5.75169 m 2
% Excess heat transfer area ≈ 401.577 %
Heat transfer area provided minimum is Ao = 1.1469 * 1.5 = 1.72035 cm 2
= π * do * L’L’ = 1.172035 / (π * 1.5624 ) = 0.23878 m
where L’ = length of cylinder that must be covered by jacket = 0.23780 m.
However, entire height of liquid pool ( hl= 1.5624) must be covered by plain jacket as shown in fig to keep uniform temp. of entire liq. pool . Reaction temp. can be controlled by controlling the flow rate of cooling water as shown. Mechanical Design
Resulting data from the process design:-
Top head = TorisphericalOperating Pressure = 1 atmosphereDensity of Liquid = 921.7775 kg / m3 (mix)Viscosity of Liquid (mix) = 0.5368 CPType = 45 pitched blade turbineTip velocity = 200 m/ minuteDa / Dt = 113 = 0.333H / Dt = 1.0N = 123 rpm (as previous) No. of agitator required = 1 (as H/D=1)
Thickness required for external pressure > thickness required for internal pressure. Therefore stiffing ring is used to reduce cost of equipment stiffing ring is attached on the outer side.
Dimensions of stiffing ring :- W = 50 mm thick = 8 mm
As = W * T = 400 mm2
L1 = 200 mm
B = PDo = 10.6392 * Dot + AsL t + 400/200
Select ta = 8 mm t = 6.5 mm
Do = 1713.2 + 2 * 8 =1729.2B = 10.6392 X 1729.2 = 2164.38
Design of shell using stiffening ring. Stiffening ring is attached on the inside of shell.Dimensions of stiffing ring: - W = 50 mm thick = 8 mmAs = W * T = 400 mm2
L1 = 200 mmB = PDo = 11.7755 * Do
t + AS/ L1 t + 400/200
Select ta = 8 mm t = 6.5 mmDo = 1562.4 + 2 * 8 = 1578.4B = 11.7755 X 1578.4
Weight of vessel + Liquid = 2164.5768 +7581.7837+ Shaft + 6 Blades = 9746.3605 Kg + 1.09849 + 71.513
= 9818.97199 Kg
Design of Bracket Support:-
P = 4Pw (H – F) + EW H = 1.87488 to 75 nDb n F = 0.75
PW = KP1h1Do = 0.7 X 100 X 2 X 1.7292= 242.088 Kgf
P = 4Pw (H – F) / nDb + EW / n
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Db = Jacket shell OD + 150 mm= 17292 + 150 = 17442
P = 4 X 242.088 X (1.87488 + 0.75 – 0.75) / (4 X 1.744) + 9818.97 /4= 2714.998 Kgf
Bracket Design :- Given size of base plate = 150 mm X 150 mm A= 150 mm B = 150 mm a = 140 mm (assumed) distance between two gusset
plateAverage pressure = P /B = 2714.998 / 14 X 15 = 12.9285 Kgf / cm2
Maximum bending stress created in the base plate:-
Fmax = 0.7 Pav B2 (a4)T2 B4+a4
T12 = 0.557789 cm2 = 7.468 mm
T1 = 0.7468 cmUse 8 mm thick base plate Gusset plate thicknessMax bending stress acting in a distance parallel to the edge of gusset platefmax = 3 PC X 1
T2h2 CoSP = 2714.998 KgfC = Bolt circle diameter – OD of reactor / 2
= 1.744 – (1.5724) / 2= 0.0858 m
h = 145 mm (assumed)tan = 150 / 145-10 = 48fmax = Max allowable bending stress
= 1575 Kgf / cm2
1575 = 3 X 2714.998 X 8.58 / T2 X 14.52 X COS48T2 = 3.15 mm
Take T2 = 4 mm
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Chapter 8: Instrumentation and Process Control
Instrumentation and process control use for Phenol continuous stirred tank reactor is shown in the figure.
Reaction taking place in this reactor is exothermic but heat of reaction is very low 0.0110526 KJ/mol & feed streams are introduced at room temperature. Hence to control the reaction temperature 60 ºC saturated steam is supplied through jacket.
Following instruments and control methodology are used controlling process variable in the reactor.
1) Temperature Controller 2) Pressure Controller 3) Liquid Level Controller
1) Temperature Controller
Temperature of Phenol reactor is control by controlling the flow rate of saturated steam to the temp of Phenol reactor depend on Acetone to oxygen ratio in the reactor. Increase in Acetone air ratio favors the low exothermic reaction.
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Example: Increase in the temp of the reactor above the control valve will give the signal to the control valve placed in the inlet line of the saturated steam to the carburetor and it will increase flow rate of saturated steam. Increase flow rate of saturated steam will increase the vaporization rate of Acetone and hence increase the Acetone to air ratio.
2) Pressure Controller
Reactor is operated at pressure close to atmospheric pressure. Hence pressure control (on reaction side) is not required. Hence pressure indicator is provided on reaction side. However acetone of rxn mass is continuously removed in a vapor form. Hence Pressure Indicator & Pressure safety valves are provided.
3) Liquid level controller: - It is controlled by controlling the flow rate of product.
Chapter 9: Plant Layout & Location
Plant layout:-
Plant layout can play an important part in determining construction and manufacturing cost and thus must be planned carefully with attention being given to future problems that may arise. Since each plant differs in many ways and no two plants are exactly alike. There is no one ideal plant layout. However proper plant layout in each case will include arrangement of processing areas, storage areas, and handling areas in efficient coordination and with regard to such factors as:
Factors in planning layout:-
(1) New site development or addition to previously developed Site.(2) Type and quantity of products to be produced.(3) Type of process and product control.(4) Operational convenience and accessibility.(5) Economic distribution of utilities and services.(6) Type of building and building code requirement.(7) Health and safety consideration.(8) Waste disposal problems.
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(9) Auxiliary equipment.(10)Space available and space required.(11)Roads and railroads.(12)Possible future expansion.
Principal of planning layout:-
(1) Storage area should not be provided nearby the process if explosive material is used, here Phenol & Cumene as stored at the topmost area quite away from process area with a space for future expansion.
(2) Control room may be provided in the process area at sufficient height with glass windows, so that plants become visible to the engineer sitting inside.
(3) Boiler and other utility should not be provided in the process area.Fuel for the boiler should be near to the boiler.
(4) Three cooling towers are located in one line at the RH.S. along with the water storage facilities with E.T.P. plant following it.
(5) Administrative office, marketing office, canteen should be provided on the other side of the process area.
(6) Figure shows the suggested layout based on unit concept.(7) Also, all the basic arrangements for road, security etc. are been incorporated in the
layout.
Plant Location :-
The location of plant is one of the prime factors in deplaning of new establishment. The geographical location of the final plant can have strong influence on the success of an industrial venture.
Following factor should consider in choosing the plant location:-Availability of Raw Material:-When cumene is used as a raw material it should be located near a petrochemical refinery where benzene can be obtained easily which is a raw material for cumene production.
Location of market:Product is used in laminates, varnishes, resins, air freshener, pharmaceutical, plastics, dye Industries.Market is easily available if plant situated near to this companies.
Transportation and communication:People and goods must be conveniently transported to and from the plant satisfactorily. Plant must have both road and rail facility.
Labor and skilled workers:A large portion of product cost of any manufactured item is represented by labor costs. So location should be such that labor and skilled workers are easily available.
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Utilities:Location must have adequate water supply and ample supply of electricity should be available at or new location economic, availability of fuel, coal or gas is also prime consideration.
Suitable land:Sufficient land should be available for proposed plant and for future expansion. The land should be flat and should have suitable load bearing characteristics.
Effluent Disposal:Full consideration must be given to the difficulties and cost of disposal of waste.The plant must have separate disposal unit. Near plant location a centralized system for drainage may be available.
Climate:It is desirable to locate a plant where climate conditions are most favorable for ease of operation for plant and personnel.
Local community consideration:The plant should be closed to local community and should not imposing any big risk to people and environment.
Chapter 10: Safety & Environment
List of Safety Equipments at Industry
a) They provide HELMET, EAR PLUG, GOGGLES, FACE SHIELD, HAND GLOVES, APRONS, SAFETY SHOES personal protective equipments.
b) Warning Instruments:- Oxygen, Carbon dioxide, Cumene, cumene hydroperoxide indicator with respectable sensor.
c) Fire Extinguisher is also provided on each an every point and a First aid Boxes at all floor where employees are working. Type of Fire Extinguisher:-
1. Soda Acid Fire Extinguisher2. Foam Type Fire Extinguisher3. Carbon Dioxide Fire Extinguisher4. Dry Chemical Fire Extinguisher5.
Emergency Overview: POISON! DANGER! MAY BE FATAL IF SWALLOWED, INHALED OR ABSORBED THROUGH SKIN. RAPIDLY ABSORBED THROUGH SKIN. CORROSIVE. CAUSES SEVERE BURNS TO EVERY AREA OF CONTACT. AFFECTS CENTRAL NERVOUS SYSTEM, LIVER AND KIDNEYS. COMBUSTIBLE.
Lab Protective Equip: GOGGLES & SHIELD; LAB COAT & APRON; VENT HOOD; PROPER GLOVES; CLASS B EXTINGUISHER Storage Color Code: White Stripe (Store Separately)
Inhalation: Breathing vapor, dust or mist results in digestive disturbances (vomiting, difficulty in swallowing, diarrhea, loss of appetite). Will irritate, possibly burn respiratory tract. Other symptoms listed under ingestion may also occur.
Ingestion:-Poison. Symptoms may include burning pain in mouth and throat, abdominal pain, nausea, vomiting, headache, dizziness, muscular weakness, central nervous system effects, increase in heart rate, irregular breathing, coma, and possibly death. Acute exposure is also associated with kidney and liver damage. Ingestion of 1 gram has been lethal to humans.
Skin Contact:-Corrosive. Rapidly absorbed through the skin with systemic poisoning Effects to follow. Discoloration and severe burns may occur, but may be disguised by a loss In pain sensation.
Eye Contact:-Corrosive. Eye burns with redness, pain, blurred vision may occur. May cause severe damage and blindness.
First Aid Measures:-
Inhalation:-Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention immediately.
Ingestion:-If swallowed, immediately administer castor oil or other vegetable oil. Never give anything by mouth to an unconscious person. Be ready to induce vomiting at the advice of physician or poison control center. Castor oil (or vegetable oil) dosage should be between 15 and 30 cc. Get medical attention immediately.
Skin Contact:-In case of skin contact, immediately flush skin with large amounts of water while removing contaminated clothing and shoes. As soon as possible, repeatedly apply polyethylene glycol to affected area. Destroy contaminated clothing and shoes. Flush skin with water for at least 30 minutes. It is very important to avoid rubbing or wiping affected parts which would aggravate irritation and cause product dispersion. Continue treatment until the burned area changes color from white to pink. Expect that this can take a long period of time (20 minutes or more). The polyethylene glycol application should be done during transportation to the hospital. If polyethylene glycol is not available, flush with water for at least 30 minutes prior to going to hospital. Get medical attention immediately.
Eye Contact:-Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately.
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Fire Fighting Measures:-
Explosion:-Above flash point, vapor-air mixtures are explosive within flammable limits noted above. Sealed containers may rupture when heated.
Fire Extinguishing Media:-Water spray, dry chemical, alcohol foam, or carbon dioxide. Water spray may be used to keep fire exposed containers cool.
Special Information:-In the event of a fire, wear full protective clothing and NIOSH-approved self-contained breathing apparatus with full face piece operated in the pressure demand or other positive pressure mode. Structural firefighter's protective clothing is ineffective for fires involving this material. Stay away from sealed containers.
Handling and Storage:-
Keep in a tightly closed container. Store in a cool, dry, ventilated area away from sources of heat or ignition. Protect against physical damage. Store separately from reactive or combustible materials, and out of direct sunlight.
Avoid dust formation and control ignition sources. Employ grounding, venting and explosion relief provisions in accord with accepted engineering practices in any process capable of generating dust and/or static electricity. Empty only into inert or non-flammable atmosphere.
All phenol operations should be enclosed to eliminate any potential exposure routes. Containers of this material may be hazardous when empty since they retain product residues (dust, solids); observe all warnings and precautions listed for the product.
Ecological Information:-
Environmental Fate:-When released into the soil, this material is expected to readily biodegrade. When released into the soil, this material is not expected to leach into groundwater. When released into the soil, this material may evaporate to a moderate extent. When released into the soil, this material is expected to have a half-life between 1 and 10 days.
When released into water, this material is expected to readily biodegrade. When released into water, this material is not expected to evaporate significantly. When released into water, this material is expected to have a half-life between 10 and 30 days. This material has an estimated bioconcentration factor (BCF) of less than 100. This material is not expected to significantly bioaccumulate. When released into the air, this material is expected to be readily degraded by reaction with photochemically produced hydroxyl radicals.
When released into the air, this material may be moderately degraded by photolysis. When released into the air, this material is expected to have a half-life of less than 1 day.
Environmental Toxicity:-This material is expected to be toxic to aquatic life. The LC50/96-hour values for fish are between 10 and 100 mg/l.
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Toxicological Information:-
Oral rat LD50: 317 mg/Kg; skin rabbit LD50:630 mg/kg; inhalation rat LC50: 316 mg/m3; irritation data: skin rabbit, standard Draize, 500 mg/24H severe; eye rabbit, standard Draize 5 mg/30S rinse, mild. Investigated as a tumorigen, mutagen, and reproductive effector.
Appearance: colourless crystals with a characteristic odour Melting point: 40 - 42 C Boiling point: 182 C Specific gravity: 1.07 Vapour pressure: 0.35 mm Hg at 20 C Flash point: 79 C Explosion limits: 1.5 % - 8.6 % Autoignition temperature: 715 C
Stability
Stable. Substances to be avoided include strong oxidizing agents, strong bases, strong acids, alkalies, calcium hypochlorite. Flammable. May discolour in light.
Toxicology
This material is a systemic poison and constitutes a serious health hazard. The risks of using it in the laboratory must be fully assessed before work begins. Vesicant. Typical MEL 2 ppm; typical OEL 1 ppm. Acute poisoning by ingestion, inhalation or skin contact may lead to death. Phenol is readily absorbed through the skin. Highly toxic by inhalation. Corrosive - causes burns. Severe irritant.
Income tax = 40% of (Gross profit – Sales tax) = 151688000 Rs.
Net Profit = 392800000 – 151688000 = 241100000 Rs.
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Profitability Analysis:
Annual investment after income tax = (net profit/ total capital investment) x 100 = (241100000/233378500) x100 = 103.308 %
Pay out period without interest = (depreciable fixed capital investment/(avg. profit + avg. depreciation/yr.)) = 186702500 / (241100000 + 21140000) = 8 months.
Break even analysis:
Total production cost = 286184000 Rs.Total Production = 11550 TPA
At Break even point, Total Sales = Total Production Cost X x 11550 x 70 x1000 = 286184000 X = 0.22 yr. = 3 months.(approx.)
In terms of tons, Phenol = 75600 & Acetone = 1887.84
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Chapter 13: Manufacturers of Phenol
Industries in India:-
- Herdillia Chemical Ltd. Mumbai, Maharashtra- Kinjal chemicals A’ bad Gujarat- Hindustan organic chemical ltd., Mumbai, Maharashtra- Nile chemicals, Mumbai, Maharashtra- Ultimate chemicals Pvt. Ltd. Mumbai, Maharashtra- Bombay lubricants oil company, Mumbai, Maharashtra- Lawrice labs, Mumbai, Maharashtra- Rocky chemicals, Ankleshwar- BL chemicals, Mumbai, Maharashtra
Industries in abroad:-
- Mitsui chemicals, Japan (World’s 1st manufacturer)- Kumho P & B chemicals, Korea (World’s 2nd manufacturer)- Arian chemie co. , Iran- A.K. Aromatics, Saudi Arabia- Christopher KIM, Canada- J.N. Global, South Korea- Beijing Jiyi chemical and industry co. ltd., China
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Chapter 13: Conclusion
From the above process I can conclude that the process which I have selected is the most appropriate and the most of the industry in India and abroad use the same for the manufacturing of phenol as Acetone which has got a great market demand is also obtained as co-product.
As phenol is also absorbed by skin on long exposure wear impervious protective clothing, including boots, gloves, lab coat, apron or coveralls, as appropriate, to prevent skin contact. Butyl rubber and neoprene are suitable materials for personal protective equipment. Use chemical safety goggles and/or full face shield where dusting or splashing of solutions is possible. Maintain eye wash fountain and quick-drench facilities in work area.
On the basis of material balance one can conclude that 1tph of cumene gives approx. 1.45 tph of phenol and 0.87 tph of acetone as product and co-product respectively.
Also, here the optimization is done at various places especially at stream 18 where the residue of the previous distillation column is used to heat the feed to the reactor-3 and inturn the residue is being cooled.
From the design point of view the thing which is clear is M.O.C. of th reactor which I have designed should be S.S. 304 as phenol is corrosive and also sulfuric acid is being added as a catalyst in the process. Also as there is a great density difference in that of sulfuric acid and phenol an agitator is very much compulsory.
Lastly, the cost estimation shows that the process is quite a profitable process with Payout period = 8 months Break Even point = 3 monthNet Profit = 24.11 crore.
Thus, on the basis of above mentioned points if one is interested in manufacturing the Phenol as a product then it’s a profitable venture.
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Chapter 14: References
HAND BOOK AND ENCYCLOPEDIA
1. Kirk-Othmer, Concise “Encyclopedia of Chemical Technology”, vol- A 19 Page – 299-308
2. Ullmans “ Encyclopedia of industrial chemistry”, vol-A11 Page – 385-3923. Perry J.H. “Chemical Engineering Hand book”, 6th Edition. Page-48-98
BOOKS
4. Dryden “Outlines of Chemical Technology”, 3rd edition, East West Press. Page. no – 504-520
5. B.I Bhatt and S.M. Vora “ Stoichiometry” 4th edition ,Tata McGraw hill publisher Page no-129-133
6. Coulsen Richard & R. K. Sinnot “Process Engineering and Design” Vol-67. S.B.Thakore & B.I. Bhatt “Process Engineering and Design, Tata McGraw hill
publisher Page. no- 720-725,219, 8. Edwin H Young & Cloyd E Brownell “Process Equipment Design”.Page.no- 246-
247.9. S.B.Thakore & D.A.Shah “Illustrated Process Equipment Design”,1st edition, Atul
Prakashan.Page.no-79-82,232-240, 70-71.10. Klaus Timmerhaus “Process Plant design & economics for chemical engineer”,3rd
edition , Tata McGraw Hill Publisher.Page-No-95-102,150-20911. C S Rao “Environmental pollution control engg.”, New Age International (P) Ltd.