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MANUFACTURE OF ACETONITRILE
Prepared by:-Isha Shah
-Bhavik Sheth-Aliasgar Mandsaurwala
Product Name: Acetonitrile Molecular formula: CH3CN
Synonyms: Cyanomethane, ethyl nitrile, methyl cyanide, ethane nitrile, methane carbonitrile, AN, ethanonitrile
Acetonitrile is a liquid at room temperature and has an ether-like odor. Acetonitrile is miscible with water, methanol, methyl acetate, acetone, ether,
chloroform, carbon tetrachloride, and many saturated and unsaturated hydrocarbons. It is immiscible with many saturated hydrocarbons (petroleum fractions).
It has a convenient liquid range and a high dielectric constant of 38.8. With
a dipole moment of 3.92 D, acetonitrile dissolves a wide range of ionic and nonpolar compounds and is useful as a mobile phase in HPLC and LC-MS The N-C-C skeleton is linear with a short C-N distance of 1.16 Å.
Introduction
Molecular weight: 41.05 Boiling point: 81.60°C Vapor pressure: 88.8 Torr at 25°C Freezing point: -43.8°C Refractive index: 1.3441 at 20°C Density: 0.7822 g/mL (6.527 lb/gal) at 20°C 0.7766 g/mL (6.481 lb/gal) at 25°C Solubility in water: Miscible in all proportions Appearance: Colorless liquid
Physical properties
Chemical properties Acetonitrile is very soluble in water. It mixes with most organic solvents, e.g. alcohols, esters, acetone, ether, benzene,
chloroform, carbon tetrachloride and many unsaturated hydrocarbons. Acetonitrile does not mix with petroleum ether and many saturated hydrocarbons. Acetonitrile is incompatible with water, acids, bases, oleum, perchlorates, nitrating agents,
reducing agents and alkali metals. Acetonitrile decomposes on contact with acids, water and steam, producing toxic fumes
and flammable vapour. Acetonitrile reacts with strong oxidants such as nitric acid, chromic acid and sodium
peroxide, causing fire and explosion hazards. Acetonitrile forms toxic fumes of hydrogen cyanide and nitrogen oxides on combustion. It
attacks some forms of plastics, rubber and coatings. Reactivity Profile
Acetonitrile decomposes when heated to produce deadly toxic hydrogen cyanide gas and oxides of nitrogen. Strongly reactive. May react vigorously with strong oxidizing reagents, sulfuric acid, chlorosulfonic acid, sulfur trioxide, perchlorates, nitrating reagents, and nitric acid.
1. As a chemical intermediate in pesticide manufacturing. 2. Solvent for both inorganic and organic compounds; 3. Starting material for the production of acetophenone, alpha-
naphthalenacetic acid, thiamine, and acetamidine. 4. In the production of acrylic fibers; 5. In pharmaceuticals, 6. extraction solvent for butadiene. 7. Its ultraviolet transparency UV cutoff, low viscosity and low chemical
reactivity make it a popular choice for high-performance liquid chromatography (HPLC).
8. Acetonitrile plays a significant role as the dominant solvent used in the manufacture of DNA oligonucleotides from monomers.
9. Industrially, it is used as a solvent for the manufacture of photographic film.
Applications
Indian Scenario World Scenario Export data: India exported ACETONITRILE worth USD 1762162
with total quantity of 6000 tonne per annum. Import data: India imported ACETONITRILE ORGANIC
CHEMICAL worth USD 185250 with total quantity of 2000 tonne per annum
As compared to the 2000 tonne/annum of acetonitrile imported, 6000 tonne/annum is exported. Since the export of acetonitrile exceeds its imports we see that a part of the demand for acetonitrile in the international market is met by India. Hence our decision to manufacture a safe amount of 3200 tonne/annum of acetonitrile when there is a deficit of 4000 tonne/annum.
Economic Scenario
1. The BP (Distillers)-Ugine process. 2. Societa Nazionale Metanodotti (SNAM) Process 3. Montedison Process 4. Acetonitrile manufacture by ammoxidation of
propylene (SOHIO Process)
Different Manufacturing Processes
Process Selected : SOHIO Process The manufacturing of acrylonitrile by ammoxidation of propene remains
highly. Competitive because of the high performance achieved with the modern
catalysts based on molybdenum/antimonium oxides. The conversion of propene is practically complete, while the ammonia and
oxygen are used in amounts close to stoichiometry. Fluid - bed - reactor technology allows short reaction times and very high
heat - transfer coefficients to be achieved, by preserving safety despite the potential explosive reaction mixture and very high exothermic effect. The separation of acetonitrile from acetonitrile by extractive distillation with water can be done in a more efficient two - column heat integrated setup.
The separation of acrylonitrile from water, which is hindered by the existence of an azeotrope, can actually take advantage of the large immiscibility gap. Valuable byproducts, such as HCN and acetonitrile can be efficiently separated. Chemical conversion can solve the separation of difficult impurities, such as acroleine.
About 90% of the worldwide acrylonitrile (AN) is manufactured today by the ammoxidation of propene.
Highly exothermal ( Δ H = − 123 kcal/mol) Temperatures of 300 – 500 ° C Pressures of 1.5–3 bar in fluid bed or fixed bed reactors. The first commercial plant built by Sohio (now BP International) used a catalyst based
on Bi2O3.MoO3. Numerous chemical formulations have been patented. The catalyst should be
multifunctional and possess redox properties. The most commonly employed contain molybdenum or antimonium oxides mixed
with transition metals, such as Fe, Ni, Co and V, activated by alkali and rare earth elements.
yield in acrylonitrile of 80 – 82%, mainly because of losses in propene by combustion. Significant amounts of highly toxic species form, such as HCN, acetonitrile (ACN)
and heavy nitriles. Their removal from aqueous mixtures is difficult, as reflected in elevated water treatment and energy costs.
Process Description
CH2=CH-CH3 + NH3 + 3/2O2 → CH2= CH - CN (AN) + 3H2O Conversion= 0.801
2CH2=CH-CH3 + 3NH3 + 3/2O2 → 3 CH3- CN (ACN) + 3H2O Conversion=
0.021
CH2=CH-CH3 + 3NH3 + 3O2 → 3HCN + 6H2O Conversion= 0.027
CH2=CH-CH3 + 9/2O2 → CH2= 3 CO2+ 3H2O Conversion= 0.107
CH2=CH-CH3 + O2 → CH2= CH2=CH-CHO (ACR)+ H2O Conversion= 0.027
CH2=CH - CN + HCN → NC-CH 2-CH2-CN (Dinitrile Succinate) Conversion= 0.005
CH2=CH - CHO + HCN → NC-CH 2-CH2-CHO ( propion- cyanhydrine)
Chemical Reactions
BASIS: 96000 tonne/annum of acrylonitrile produced. 96000 tonne/year = 12500 kg/hr ( considering 320
days ) = 235.849 kmol/ hr of acrylonitrile. We get propylene fed= 363.183 kmol/hr Yield of Acrylonitrile = 81% Conversion = 80.10% propylene fed = 363.183 Acetonitrile Produced =10.70495642 Feed Ratio = Propene : Ammonia : Air 1:1.2:9.5
Mass Balance
Reactor Input for Reactor Components Weight Weight % Moles Mole % Propylene 15253.686 12.5 363.183 8.5 Air 96606.678 81.4 3450.2385 81.2 Ammonia 7408.9332 6.1 435.8196 10.3 Total 119269.297 100 4249.2411 100 output for reactor Component Amount Molecular
Weight Amount2 Mole %
Propylene 6.174 42 259.308 0.138 Oxygen 28.14 32 900.48 0.629 Nitrogen 2760.184 28 77285.152 61.8 Ammonia 104.052 17 1768.884 2.33 carbon dioxide 116.58 44 5129.52 2.6 HCN 29.42 27 794.34 0.66 AN 290.89 53.1 15446.259 6.5 Acrolein 9.81 56.1 550.341 0.219 Acetonitrile 11.43 41.1 469.773 0.256 Water 1112.22 18 20019.96 24.88 Total 119269.297
Reactor inlet = reactor outlet = 119269.297
Reactor 2 composition of gas stream entering Reactor 2
Component AmountMolecular Weight Amount2 Mole %
Propylene 6.174 42 259.308 0.138
Oxygen 28.14 32 900.48 0.629
Nitrogen 2760.184 28 77285.152 61.8
Ammonia 104.052 17 1768.884 2.33
carbon dioxide 116.58 44 5129.52 2.6
HCN 29.42 27 794.34 0.66
AN 290.89 53.1 15446.259 6.5
Acrolein 9.81 56.1 550.341 0.219
Acetonitrile 11.43 41.1 469.773 0.256
Water 1112.22 18 20019.96 24.88
Total 119269.297
composition of Quenching media 30% sulphuric acid
componentAmount Kmoles Molecular Wt Amount in kg Mol %
Water 794.058 18 14298.893 92.7
Sulphuric Acid 62.531 98 6128.0977 7.3
Total Amount of Quenching Media = 20426.9907 kg/hr
Total input= 119269.297 + 20426.9907 139696.288 kg/h
composition of Components leaving at the top
component Amount Kmoles Molecular Wt Amount in kg Mol %Propene 6.174 42 259.308 0.19oxygen 28.14 32 900.48 0.85
nitrogen 2760.184 28 77285.152 83.8co2 116.58 44 5129.52 3.54HCN 29.1258 27 786.3966 0.88
AN 287.9811 53.1 15291.7964 8.74
Acrolein 9.7119 56.1 544.83759 0.29
Acetonitrile 11.3157 41.1 465.07527 0.34
water 44.03 18 16779.734 1.34
total amount of gaseous component leaving = 117442.3kg/hr
composition of components leaving at the bottom
component Amount Kmoles Molecular Wt Amount in kg Mol %HCN 0.2942 27 7.9434 0.032sulphuric acid 10.425 98 1021.65 1.2
ammonium sulphate 51.22 132 6761.04 6.06
AN 2.9089 53.1 154.46259 0.39Acrolein 0.0981 56.1 5.50341 0.012Acetonitrile 0.1143 41.1 4.69773 0.013
water 794.372 18 14298.696 92.34
total amount of components leaving at the bottom = 22253.9931kg/hr
total output = 117442.3 + 22253.9931 = 139696.288kg/hr
Decanter
composition of components entering Decanter
component Amount Kmoles Molecular Wt Amount in kg Mol %
Propene 6.174 42 259.308 0.17
oxygen 28.14 32 900.48 0.8
nitrogen 2760.184 28 77285.152 76.94
co2 116.58 44 5129.52 5.11
HCN 29.1258 27 786.3966 0.7
AN 287.9811 53.1 15291.7964 7.61
Acrolein 9.7119 56.1 544.83759 0.27
Acetonitrile 11.3157 41.1 465.07527 0.23
water 932.207 18 16779.734 8
total amount of components entering= 117442.3
Decanter Composition of components leaving at the top of decanter
component Amount Kmoles Molecular Wt Amount in kg Mol %
Propene 6.174 42 259.308 0.19
oxygen 28.14 32 900.48 0.85
nitrogen 2760.184 28 77285.152 83.8
co2 116.58 44 5129.52 3.54
HCN 26.222 27 707.994 0.88
AN 143.99 53.1 7645.869 8.74
Acrolein 4.85 56.1 272.085 0.29
Acetonitrile 5.6525 41.1 232.31775 0.34
water 445.1494 18 8012.6892 1.34
total amount of components leaving at top = 100445.415
composition of components leaving at the bottom of decanter
component Amount Kmoles Molecular Wt Amount in kg Mol %
Propene 0 42 0 0
oxygen 0 32 0 0
nitrogen 0 28 0 0
co2 0 44 0 0
HCN 2.9038 27 78.4026 0.04
AN 143.9911 53.1 7645.92741 22.34
Acrolein 4.8619 56.1 272.75259 0.754
Acetonitrile 5.6632 41.1 232.75752 0.878
water 487.058 18 8767.044 75.57
total amount of components leaving top of decanter= 16996.8841
total output = 100445.415 + 16996.8841 = 117442.299
Absorber composition of components in gaseous feed
componentAmount Kmoles Molecular Wt Amount in kg Mol %
Propene 6.174 42 259.308 0.19
oxygen 28.14 32 900.48 0.85
nitrogen 2760.184 28 77285.152 83.8
co2 116.58 44 5129.52 3.54
HCN 26.222 27 707.994 0.88
AN 143.99 53.1 7645.869 8.74
Acrolein 4.85 56.1 272.085 0.29
Acetonitrile 5.6525 41.1 232.31775 0.34
water 445.1494 18 8012.6892 1.34
total amount of components entering the absorber= 100445.415
total amount of water entering the absorber 96337.9494 kg/hr
total input = 100445.415 + 96337.9494=196783.3644 kg/hr
composition of components leaving at the top
component Amount Kmoles Molecular Wt Amount in kg Mol %
Propene 6.174 42 259.308 0.2
oxygen 28.14 32 900.48 0.94
nitrogen 2760.184 28 77285.152 92.76
co2 116.58 44 5129.52 3.92
AN 0.7156 53.1 37.99836 0.02
Acrolein 2.927 56.1 164.2047 0.1
water 61.4518 18 1106.1324 2.06
total amount of components leaving as off gases= 84882.7955
composition of components leaving at the bottom
component Amount Kmoles Molecular Wt Amount in kg Mol %
HCN 26.222 27 707.994 0.44
AN 143.2636 53.1 7607.29716 2.42
Acrolein 1.9229 56.1 107.87469 0.03
Acetonitrile 5.6525 41.1 232.31775 0.1
water 5736.1079 18 103249.942 97
total amount of components leaving at the bottom= 111905.426
total output= 84882.7955 + 111905.426 = 196788.4
Stripping column
composition of components entering at stripping section from decanter and absorber
componentAmount Kmoles
Molecular Wt
Amount in kg Mol %
HCN 29.1238 27 786.3426 0.4441
AN 287.1746 53.1 15248.9713 4.379
Acrolein 6.7848 56.1 380.62728 0.103
Acetonitrile 11.3157 41.1 465.07527 0.1725
water 6223.165 18 112016.97 94.9
total amount entering= 128897.986 kg/h
composition of components leaving stripping section at top
component Amount Kmoles Molecular Wt Amount in kg Mol %
HCN 28.7534296 27 776.3426 8.67310651
AN 244.0984 53.1 12961.625 73.6284241
Acrolein 5.1203 56.1 287.25 1.54445756
Acetonitrile 11.1973 41.1 460.211 3.37748856
water 42.358 18 762.44 12.7767522
total components leaving at top= 15247.8686kg/h
composition of components leaving stripping section at bottom
component Amount Kmoles Molecular Wt Amount in kg Mol %
HCN 0.3704 27 10.0008 0.00559007
AN 43.0762 53.1 2287.34622 0.69187189
Acrolein 1.6645 56.1 93.37845 0.0267345
Acetonitrile 0.1184 41.1 4.86624 0.00190169
water 6180.807 18 111254.526 99.2735347
total components leaving stripping section at bottom = 113650.118kg/h
total output = 15247.8686+113650.118= 128897.986
Column C 1-ARaw AN
HCN, AN, Acrolein, Acetonitrile
HCN, AN, Acrolein, Acetonitrile, Water.
Compositipn of components entering C1-A
componentAmount Kmoles Molecular Wt Amount in kg Mol %
HCN 28.7534296 27 776.3426 8.67310651
AN 244.0984 53.1 12961.625 73.6284241
Acrolein 5.1203 56.1 287.25 1.54445756
Acetonitrile 11.1973 41.1 460.211 3.37748856
water 42.358 18 762.44 12.7767522
total components entering = 15247.8686 kg/h
composition of components leaving at top
component Amount Kmoles Molecular Wt Amount in kg Mol %
HCN 28.552 27 770.904 8.77544817
AN 239.21 53.1 12702.051 73.5211178
Acrolein 5.1203 56.1 287.24883 1.57369357
Acetonitrile 10.97 41.1 450.867 3.37156386
water 41.51 18 747.18 12.7578501
total components leaving at top= 14958.2508 kg/h
composition of components leaving at bottom
component Amount Kmoles Molecular Wt Amount in kg Mol %
HCN 0.201 27 5.427 0.06062909
AN 4.8884 53.1 259.57404 1.47450859
Acrolein 0 56.1 0 0
Acetonitrile 0.2273 41.1 9.34203 0.06856145
water 0.848 18 15.264 0.25578842
total components leaving at bottom= 289.60707kg/h
total output= 15247.857kg/h
Column C 1-BHCN, DNS, PC
AN, Acetonitrile, Water
composition of components entering C1-B
componentAmount Kmoles Molecular Wt Amount in kg Mol %
HCN 28.552 27 770.904 8.77544817
AN 239.21 53.1 12702.051 73.5211178
Acrolein 5.1203 56.1 287.24883 1.57369357
Acetonitrile 10.97 41.1 450.867 3.37156386
water 41.51 18 747.18 12.7578501
total components entering= 14958.2508 kg/h
composition of components leaving at top
componentAmount Kmoles Molecular Wt Amount in kg Mol %
HCN 18.6231 27 502.8237 65.2906035
dinitrile succinate 4.78 80 382.4 16.7581705
propion cyandhydrine 5.1203 83 424.9849 17.951226
total components leaving at top= 1310.2086 kg/h
Composition of components leaving at bottom
componentAmount Kmoles Molecular Wt Amount in kg Mol %
HCN 0.201 27 5.427 0.06062909
AN 4.8884 53.1 259.57404 1.47450859
Acrolein 0 56.1 0 0
Acetonitrile 0.2273 41.1 9.34203 0.06856145
water 0.848 18 15.264 0.25578842
total components leaving at bottom= 289.60707 kg/h
total output= 15247.857 kg/h
Column C 2
component Amount Kmoles
Molecular Wt
Amount in kg
Mol %
HCN 0.201 27 5.427 0.06863481
AN 239.318 53.1 12707.7858
81.7191347
Acetonitrile 10.9773 41.1 451.16703 3.74838273
water 42.358 18 762.444 14.4638477
Components entering column C2 is mixture of C1-A bottom and C1-B bottom
Total components entering from column = 13926.8238 kg/hrWater entering is in the ratio of 10:1 with solvent/mixtureWater entering in column C-2 = 139268.23 kg/hr Components leaving at top of column C-2
component Amount Kmoles Molecular Wt Amount in kg Mol %
AN 236.924 53.1 12580.6644 99.643733
water 0.8471 18 15.2478 0.35626701
total leaving at top = 12595.9122 kg/h
Components entering Decanter 2
component Amount Kmoles Molecular Wt Amount in kg Mol %
AN 236.924 53.1 12580.6644 99.5416255
water 0.8471 18 15.2478 0.35590194
water leaving from decanter 2 to C-2= 15.2478kg/h
water entering from decanter to C-2= 15.2478kg/h
components leaving from middle of C-2
component Amount Kmoles Molecular Wt Amount in kg Mol %
Acetonitrile 10.231 41.1 420.4941 0.02933394
water 34867.46 18 69734.925 99.9706689
total components leaving= 70155.4191kg/h
water leaving from C-2= 69734.927 kg/h
Acrylonitrile entering from decanter 2 to C-4=
component Amount Kmoles Molecular Wt Amount in kg
AN 236.924 53.1 12580.6644
total input in C-2 = 13926.823+139268.23+15.2478= 153210.301kg/h
total output from C-2= 12595.9+70155.4+69734.9+12580.6= 153208.32kg/h
Column C 4Water
Product AN
composition of components entering C-4
componentAmount Kmoles Molecular Wt Amount in kg Mol %
AN 236.924 53.1 12580.6644 99.78
Water 0.521 18 9.378 0.22
Total input= 12590.04 kg/h
composition of components leaving at top
water= 29.3686 kg/h
composition of Acrylonitrile leaving from C-4 = 235.97kmol/h
12530.341 kg/h
total output= 29.3686 + 12530.341= 12529.7096 kg/h
Column C 3Raw ACN
water
composition of Components entering C-3
componentAmount Kmoles
Molecular Wt
Amount in kg Mol %
Acetonitrile 10.231 41.1 420.4941 0.02933394
water 34867.46 18 69734.925 99.9706689
total input= 70155.4191
composition of Acetonitrile leaving from top
componentAmount Kmoles
Molecular Wt
Amount in kg Mol %
Acetonitrile 10.1287 41.1 416.28957 100%
composition of water leaving from bottom
componentAmount Kmoles
Molecular Wt
Amount in kg Mol %
Acetonitrile 0.1023 41.1 4.20453 0.00029331
water 34867.46 18 69734.925 99.9706689
total output= 416.28+4.2045+69743.925= 70155.4191 kg/h
Total acetonitrile produced= 10.1287 kmol/h 416.2895 kg/h
Energy Balance HEAT EXCHANGER 1 Heats propene to 200 degree celsius ( m.Cp.ΔT) propene = (m.Cp.ΔT)steam 15253.686 * 2.166* (200 – 25) = m*2.142* (40 ) m= 67482.605 kg/hr HEAT EXCHANGER 2 Heats ammonia to 200 degree celsius ( m.Cp.ΔT) ammonia = (m.Cp.ΔT)steam 7408.9332 * 2.4223* (200 – 25) = m*2.142* (40) m= 36655.75 kg/hr
Reactor 1Inlet Temperature= 200 :COutlet Temperature = 420:C
Mass in Total mCp= 150394.4128
Mass Out Total mCp= 430933.9178
Assuming Heat of the reaction = 514 KJ/molThe limiting reactant is oxygen 1mol = 514 KJ724.55 mol= 372418.74 KJ
Therefore, Heat to be removed= 150394.4128 x 473 - 430933.9178 x 693 + 372418.74= 227873.0665 MJ/hr
The heat is removed by the heat exchanger and boiler feed water.
Heat exchanger 3 delivers a heat duty of 7.8 MW = 28080 MJ/hr Hence heat used to form steam by BFW will be = 199793.0665 MJ/hr
Mass of boiler feed water required is denoted by m
Thus, m= 199793.0665 / ( 4.18 * (120-35 )) (since bfw at room temp & temp of steam is 120 C at 2 bar)= 562.322 kg/ hr
HEAT EXCHANGER 3It converts the gas from 420 : C to 220:C using DOWTHERM –A , THERMINOL® VP-1 HEAT TRANSFER FLUID (Biphenyl/diphenyl oxide (DPO) eutectic mixture). This operation delivers a heat duty of 7.8 MW = 28080 MJ/hr( m.Cp.ΔT) mixture = (m.Cp.ΔT) Therminol
28080 = m*2.76* (200)m= 50.8695 kg/hr
Reactor 2Mass in (220 deg Celsius)Total mass in= 288487.505
Mass out (200 deg Celsius)Total mass out= 272882.8359Assuming heat of the reaction = 1180.9 kJ/ molLimiting reactant is ammonia1mol = 1180.9 KJ104.052 mol= 122875.0068 KJ Therefore, Heat to be removed= 288487.505 x 493 - 272882.8359 x 473+ 122875.0068= 13273.63 MJ/hr
HEAT EXCHANGER 4It converts the gas from 200 : C to 30 : C using DOWTHERM –A , THERMINOL® VP-1 HEAT TRANSFER FLUID (Biphenyl/diphenyl oxide (DPO) eutectic mixture).
( m.Cp.ΔT) mixture = (m.Cp.ΔT) therminol
13273.63 = m*2.76 * (170)m= 28.289 kg/hr
HEAT EXCHANGER 5 for absorberWater from absorber is cooled to 5 :C in this heat exchanger using ethylene glycol.
( m.Cp.ΔT) water = (m.Cp.ΔT) ethylene glycol
9637.95 x 4.18x (30-5) = m x 2.36 x 9M = 47418.351 kg/hr
HEAT EXCHANGER 6 for stripping columnOutlet stream from absorber is cooled here and sent to Stripping columnBottom stream of absorberTotal mCp in the heat exchanger= 443883.6985
(m.Cp.ΔT)mixture = (m.Cp.ΔT) hot water
490863.9321x (70-30) = m x 4.198 x (20) M= 101183.6802 kg/hr
Stripping Column Operated under atmospheric conditionsFeed enters at a temperature of 303 KTop temp=77C= 350 KBottom temp= 100C= 373 KComponents leaving at bottom of strippingtotal mCp = 468622.032Hw= mCp total x ( Tbottom – Ttop) = 468622.032 x ( 373- 350)= 10778306.74 KJ/hr Air cooler Enthalpy for air cooler Hc = 266851.08 KJ/hrComponents entering stripping columntotal mCp = 509158.19Hf= mCp total x (- Ttop + Tfeed) = 509158.812 x (350-303) = -23930464.16
Reboiler duty = QbQb= Hd + Hc + Hw – HfAssuming Hd to be zero as it is calculated at base temperature= 34975621.98 KJ/hr
Column C-1AFeed inlet temp= 338 Ktemp at top= 313 Ktemp at bottom= 356 Kcomposition of components leaving at bottom Hw= mCp total x ( Tbottom – Ttop) =17662.68KJ/hr Composition of components enteringHf= mCp total x (- Ttop + Tfeed) =555935.1 KJ/hrCondenser heat load Qc
λ average = 858.0524 KJ/ kgtaking Reflux ratio R = 1.5 = L/ DD = 14958.278 kg/hrhence L = 22437.417m=V= L+ D = 37395.695 Qc= m x λ average= 32087450.89 KJ/ hrReboiler duty = QbQb= Hd + Qc + Hw – Hf= 31549178.47 KJ/hrAssuming Hd to be zero as it is calculated at base temperature
Column C-1BFeed inlet temp= 313 Ktemp at top= 299 Ktemp at bottom= 348 K
Hf= mCp total x (- Ttop + Tfeed) = 21825.718 x (-299+313) = 305560.92
Hw= mCp total x ( Tbottom – Ttop) =936319.6703 KJ/hrCondenser heat load Qc λ average = 1030 KJ/ kgtaking Reflux ratio R = 2 = L/ DD = 1310.2086 kg/hrhence L = 2620.4172m=V= L+ D = 3930.6258 Qc= m x λ avg= 4048544.574 KJ/ hrReboiler duty = QbQb= Hd + Qc + Hw – Hf= 4679303.324 KJ/hrAssuming Hd to be zero as it is calculated at base temperature
component λ Kj/kg
Mol %
HCN 1030 8.77544817
AN 616 73.5211178
Acrolein 502 1.57369357
Acetonitrile 729 3.37156386
water 2270 12.7578501
total components leaving at top=
HEAT EXCHANGER 7 for column C-2( m.Cp.ΔT) mixture = (m.Cp.ΔT) steam
18734.6029 x (365-348) = m x 1.926 x (450-425)M = 6614.501 kg/hr
Column C-2
total mcp = 410.476C1-BTotal mCp= 18734.598 KJ/hrHf1= mCp total x (- Ttop + Tfeed) = 18734.598 x (365-360) = 93672.99 KJ/hrHf2 = 139268.23 x 4.18 (350-360)= - 5821412.014 KJ/hr
Water leaving from C-2 = 69734.724 kg/hrHw= mCp total x ( Tbottom – Ttop) = 69734.724x 4.18 x (384- 360)KJ/hr= 6995714.88 KJ/hr
total mCp = 292855.2463Hs= mCp total x ( 368 – 360) = 6709313.692 KJ/hrAir cooler Hc= 12595.9122 x 1 x ( 87-75)= 151150.944 KJ/hr Reboiler duty = QbQb= Hd + Hw +Hc + Hs – Hf1-Hf2= 19.658 x 10^ 6 KJ/hrAssuming Hd to be zero as it is calculated at base temperature
Column C 4 Feed inlet temp= 348 Ktemp at top= 343 Ktemp at bottom= 355 K total mCp = 15186.376Hf= mCp total x (- Ttop + Tfeed) = 15186.376 x (348-343) = 75931.88 KJ/hrComposition of acrylonitrile leaving at the bottom12530.341 x 1.204 = mCp= 15086.530Hw= mCp total x ( Tbottom – Ttop) = 15086.530 x (355- 343)KJ/hr= 181038.36 KJ/hrAir cooler Composition of water leaving at top= 29.3686 kg/hr Hc= 29.3686 x 4.18 x (343 – 323)= 2455.214 KJ/hr Reboiler duty = QbQb= Hd + Hw +Hc – Hf = 107561.694 KJ/hr
Column C-3Feed inlet temp= 368 Ktemp at top= 330 Ktemp at bottom= 400 KComposition of components enteringHf= mCp total x (- Ttop + Tfeed) = 292855.2463 x (368-330) = 11128499.36 KJ/hrComposition of water leaving at the bottom69734.925 x 4.18 = mCp= 291491.98Hw= mCp total x ( Tbottom – Ttop) = 291491.98x (400-330)KJ/hr= 20404439.06 KJ/hrCondenser heat load Qc λ average = 1068 KJ/ kgtaking Reflux ratio R = 2 = L/ DD = 416.28957 kg/hrhence L = 832.579m=V= L+ D = 1248.86Qc= m x λ avg= 1333791.174 KJ/ hr Reboiler duty = QbQb= Hd + Hw +Qc – Hf = 10609.730 KJ/hr
Equipment Design- Reactor :Operating Temperature 420 C
Operating pressure 200 kPa
Design temperature 500 C
Design pressure 250 kPa
Diameter 3.28 m
Height 15.13 m
Wall Thickness .0075 m
Material Carbon steel
Volume 129 m3
Pressure Drop 10.3 kPa
Distributor
Type Gas sparger orifice type
Material Nickel
Insulation Ceramic
Catalyst
Size 60 µm
Porosity 50 %
Type Mixed oxide composition
Cooling mechanism
Cooling media Water
Cooling arrangement Coil
Thickness of shell = 4 mm (take 6 mm) Tube sheet thickness = 113.114 Torispherical head thickness = 7.14 mm height = 557.70
mm Flange design: Effective gasket seating width = b = bo since bo is less
than 6.3 mm) Therefore, b = 5 mm N (Number of bolts) = = 132 bolts Therefore, diameter of bolt db = 17.85 mm Choose M18×2 bolts, 132 in number Bolt circle diameter B = 3347.7mm Flange thickness = 84.53 mm Thickness of nozzle = 0.433 = 5 mm
Mechanical design
For system of dowtherm & light organics, the value of Uo lies in the range of 375-750W/m2 K, so assume.
Uo= 650 W/m2 K For 1 shell and 2 tube passes Lmtd = 207.2 K R = 1.1428, S = 0.44 Fr = 0.905 Corrected lmtd = 187.516 K Heat transfer area = 230 m^2 Area of tub e = 0.3679 No. of tubes = 624 Tubes/pass = 624/2= 312 Tube bundle dia = 437.25 mm Shell ID = 454 mm Shell OD = 470 mm Tube heat transfer coefficient (Hi)= 738.65 W/m2.k Shell heat transfer coefficient (Ho)= 332.6 W/m2.k Overall heat transfer coefficient = 613.68 W/m. k
Heat exchanger
Shell side: Crown Radius 470 mm Nozzles: Inlet and Outlet = 75mm Vent = 20 mm Drain = 25mm Permissible stress for Carbon steel = 95 N/mm2 Permissible Stress for Bolt material = 142 N/mm2 Tube side: Outside diameter = 20 mm Inside Diameter = 16 mm Length = 6 m Working pressure = 0.101 N/mm2 Pitch (Square) = 25mm Channel & channel cover: Nozzle = 75 mm Permissible Stress = 95 N/mm2 Gasket: Gasket Factor m = 2.5 Min. density seating stress Y = 20 N/mm2 Min. Gasket Width = 10 mm = N
Mechanical design
Design of nozzle: shell side nozzle dia =4mm Tube side nozzle dia = 4mm Shell thickness =0.3235 (take 6mm) Torispherical head ho = 80mm Torispherical head thickness = 0.4864 (take 8mm) FLANGE DESIGN: Mean Gasket Diameter G = 490 mm Basic gasket seating width = 5mm Bolt dia = 10mm Actual bolt area = 8672.565 mm2 BCD = 528 flange OD= 546mm Flange thickness = 10 mm Tube sheet thickness = 15 mm Channel thickness = 8mm Baffle thickness =6mm baffle spacing =235mm No. of tie rods = 4 Diameter of tie rods = 10 mm
Heaviest Key Component = Water Light Key Component = AN Vapour pressure of both components at avg temperature of the column i.e
63o C (336K) Vapour pressure of water (hk) = 171.4 mmHg Vapour pressure of acrolein (lk) = 427.889.84 mmHg Relative volatility α lk/hk = 427.889/171.4 = 2.496 βhk = 1- ξhk = 0.88 βlk = ξlk =0.73 No. of trays for top recovery (Nlk) = 11.69 = 12 trays No. of trays for bottom recovery (Nhk)= 13.38 = 14 trays Nt = Total No. of trays = 12.4 ~ 13 Taking tray efficiency as 80% N = Nt/0.8 = 17 trays Calculation of Reflux ratio: Reflux ratio for top recovery (Rlk)= 1.09 Reflux ratio for bottom recovery (Rhk) = 1.187 Total reflux ratio (Rt) = 0.8*(Rlk) + 0.2*(Rhk) = 1.1094 L‟ = 1.1094*14958.2508 = 16594.683 kg/hr L = 367.4845 kmol/hr V‟ = 31552.9338 kg/hr
Distillation design
V = 698.7307 kmol/hr Height of column Tray stack= 9.6mExtra feed space = 1.5m Disengagement space = 3m Skirt height = 1.5m Total height = 15.6m Flv = (L‟/V‟) (ρL/ρv) 0.5= 1.05 Csb = 0.07 ft/sec Surface tension of water = 60.8 dynes/cm Surface tension of acrylonitrile = 24.8 dynes/cm Average surface tension (σ) = 42.8 dynes/cm Flooding velocity (uf) uf = Csb*(σ/20)0.2 * [(ρL/ρv) – 1]0.5 = 0.1414 ft/sec u = 80% of uf u = 0.1131ft/sec Diameter of column V‟ = ρv * u * 0.6 * Л *D2/4 D = 2.131 m
Economic evaluation Equipment costing Reactor: L = 15.13 m = 49.639 ft D = 3.28 m = 10.76 ft Volume = 129 m3
Co = 1000 $ Lo = 4 ft Do = 3 ft α = 0.81 β = 1.05 C = 29397.46 $ Bare module cost (BMC) = C × M.F Module factor (M.F) = 4.23 Update factor (U.F) = present cost index ÷ base cost index = 169 ÷ 100
http://www.cea.nic.in/reports/hydro/presentation_cidc_4/presentation_cost_%20indices.pdf = 1.69 BMC = 124351 $ Updated BMC = U.F × BMC ( M.F – 1 ) = 678794.80 $ = 4,07,27,688 ₹ Heat exchanger: = 208186.03 $ = 1,24,91,161.85 ₹ Distillation column: =5678.4 $ = 3,40,704 ₹
Total purchasing cost of all equipments ( TEC) = Rs. 203193408=Rs.20.31 crores
Total Direct Costs D = Rs. 546111270 = 54.61 cr Total Indirect Costs = I= Rs. 13,00,43,780 = 13 cr Fixed Capital investment FCI = DIPC + Contractors Fee
+Contingency + Commission Charge =Rs. 78,43,39,857 = 78.43 cr Total Working Capital= 1083.67 cr Total Production Cost= Rs. 1098.81 cr Gross profit (taxable profit): GP = Net annual cash flow
– Total cost of production = 694.89 cr Payback period= 1.26 years
Financial analysis
To obtain the plant location we had to look at a number of aspects primarily
Availability of raw materials Industrialized Hub Market Demand for the Products Transportation and Port Access Skilled Workforce From the point of view of investement , Pro Industry
Policies and other factors aforesaid BHARUCH , GUJARAT would be an ideal location for the plant based on our preliminary research.
Plant layout and site selection
Plant layout
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