Sodium Lauryl Sulphate
Historical Background of Sodium Lauryl Sulphate
Sodium Lauryl Sulphate : When was SLS first discovered?
Sodium lauryl sulfate (SLS) was first used as an engine degreaser in World War II because the chemical was abrasive and corrosive enough to remove the toughest oils and soot. It was then brought to the United States after the Second World War and until the mid-1950’s was used for the same purpose in the product Gunk. To this day, Gunk is still sold in auto parts stores as an engine degreaser.
But not only is SLS prevalent in industrial strength cleaners, most of the hair care, household and hygiene products we use contain this harsh chemical. It all began when large corporations realized that SLS is an effective foaming agent, producing the same results in different environments and hardness levels of water. As more of these companies made the chemical, it became cheaper to manufacture. Now, it costs a few cents to make about 30% of a product such as soap or shampoo.
PHYSICAL AND CHEMICAL PROPERTIES
LAURYL ALCOHOL PROPERTIES
Physical state: Liquid (viscous)
Colour: Colourless
Odour: This information is not available
Odour threshold: No data available
Other physical and chemical parameters
pH (value): This information is not available.
Melting point/freezing point: 24 °C at 101.3 kPa
Initial boiling point and boiling range: 229 °C at 101.3 kPa
Flash point: 134,8 °C at 101,3 kPa
Evaporation rate: no data available
Flammability: (solid, gas) not relevant (fluid)
Explosive Limits
• Lower explosion limit (LEL) this information is not available
• Upper explosion limit (UEL) this information is not available
Explosion limits of dust clouds not relevant
Vapour pressure: 0.038 mbar at 38 °C
Density: 0.9 g /cm³ at 16 °C
Vapour density: This information is not available. Bulk density: Not applicable Relative density: Information on this property is not available.
Sodium Lauryl Sulphate
Water solubility: 1 mg/l at 23 °C
Partition coefficient: n-octanol /water (log KOW) 5,4 (pH value: 7,1, 23 °C) (ECHA) Auto-ignition temperature: 275 °C
Decomposition temperature: no data available
Viscosity: Not determined
PHYSICAL AND CHEMICAL PROPERTIES OF SODIUM HYDROXIDE
Chemical formula: NaOH
Molecular weight: 40.01
Synonyms: White caustic, caustic soda, soda lye, lye
CAS number: 1310–73–2
Melting point: 318. 4°C
Boiling point: 1390°C
Specific gravity: 2.13
Solubility: Soluble in water, ethanol and glycerol; insoluble in acetone and ether General characteristics: White deliquescent solid
PHYSICAL AND CHEMICAL PROPERTIES OF WATER
PHYSICAL PROPERTIES
Color: Nearly colorless with a hint of blue
Odor: None
Taste: Bland
Density: 1.000 g/ml. The density of water is approximately one gram per cubic centimeter Boiling Point: 100 °C
Sodium Lauryl Sulphate
Conductivity: Water is a good conductor of heat
Compressibility: The compressibility of water reduces the sea level
Specific Heat:Water has a high specific heat. Specific heat is the amount of energy required to change the temperature of a substance
Surface Tension: Water has a high surface tension – it is adhesive and elastic Cohesion: Water is attracted to other water
Adhesion: Water can also be attracted.
CHEMICAL PROPERTIES
Chemical Formula: H2O – two hydrogen atoms and one oxygen atom
Solvation: Water dissolves more substances than any other liquid
pH: Pure water has a neutral pH of 7, which is neither acidic nor basic
Ionization: Water weakly ionizes
PROPERTIES OF SO3
Melting Point: 144° F Alpha form 90.5° F Beta form 62.2° F Gamma form (EPA, 1998)
Vapor Pressure: 73 mm Hg at 77° F Alpha form 344 mm Hg at 77° F Beta form 433 mm Hg at 77° F Gamma form (EPA, 1998)
Vapor Density (Relative to Air): 2.76 (EPA, 1998)
Specific Gravity: 1.92 at 68 ° F Gamma form (liquid) (EPA, 1998)
Boiling Point: 113 ° F at 760 mm Hg all forms (EPA, 1998)
Molecular Weight: 80.06 (EPA, 1998)
ECONOMIC SCENARIO
EXPORT DATA
| # | Description | Quantit y | UQ C | Unit USD | Total Value USD | Destinatio n Port |
| 1 | sodium lauryl ether sulphate 1 mole (min.69% active matter) | 23460 | KGS | 1.17 | 27401.28 | jeddah |
| 2 | pharmaceutical raw materials sodium lauryl sulphate | 60 | KGS | 3.09 | 185.40 | kinshasa |
| 3 | sodium lauryl sulphate (min.90%) | 14000 | KGS | 2.91 | 40796.00 | port said |
| 4 | sodium lauryl sulphate(min. 90%) | 14000 | KGS | 2.25 | 31500.00 | montreal |
| 5 | sodium lauryl sulphate powder | 160 | KGS | 3.97 | 634.81 | benapole |
| 6 | sodium lauryl sulphate 90% | 15 | MTS | 2055.0 5 | 30825.68 | apapa |
| 7 | sodium lauryl sulphate | 1200 | KGS | 2.18 | 2612.00 | jebelali |
| 8 | sodium lauryl sulphate(min. 90%) | 15480 | KGS | 4.22 | 65341.08 | veracruz |
| 9 | sodium lauryl sulphate | 24000 | KGS | 2.30 | 55104.00 | dammam |
| 10 | sodium lauryl sulphate (min.90% | 22400 | KGS | 1.57 | 35257.60 | stpetersbur g |
| 11 | sodium lauryl sulphate (min.90%) | 20000 | KGS | 1.76 | 35120.48 | durban |
| 12 | sodium lauryl sulphate (min 90%) | 15000 | KGS | 2.60 | 39000.00 | jebelali |
| 13 | sodium lauryl sulphate (min.90%) | 24000 | KGS | 2.04 | 48909.39 | gdynia |
IMPORT DATA Sodium Lauryl Sulphate
| Date | Indian Port | Description | Qua ntity | Unit USD | Orign Port |
| 18- Nov 2016 | nhavashev a sea | emersensees 2762 (sodium lauryl ether sulphate 27%) | 660 | 0.21 | malaysia |
| 18- Nov 2016 | nhavashev a sea | emersensees 7062 (sodium lauryl ether sulphate 70%) | 1015 3 | 0.72 | malaysia |
| 02- Nov 2016 | chennai sea | sodium lauryl ether sulphate (sles) 70 in neutral new hdpe drums | 9570 | 1.22 | malaysia |
| 25-Oct 2016 | nhavashev a sea | emersense as 946n (sodium lauryl sulphate) | 1000 | 1.03 | malaysia |
| 25-Oct 2016 | nhavashev a sea | emersense as 956p (sodium lauryl sulphate) | 5000 | 1.03 | malaysia |
| 07-Oct 2016 | chennai sea | sodium lauryl sulphate (sls) 70 in neutral new hdpe drums | 9900 | 1.21 | malaysia |
| 05-Oct 2016 | chennai sea | sodium laurylsulphate (sls) 70 in neutral new hdpe drums | 1947 0 | 1.21 | malaysia |
| 05-Oct 2016 | bombay air cargo | surfac (sodium lauryl sulphate) sls | 300 | 8.33 | united kingdom |
| 16-Sep 2016 | bombay air cargo | tensopol usp94 (sodium lauryl sulphate) | 4000 | 7.49 | belgium |
| 12-Sep 2016 | nhavashev a sea | sls 30% ( sodium lauryl sulphate) | 58.41 | 404.0 0 | malaysia |
| 31- Aug 2016 | nhavashev a sea | sls powder-95 min (sodium lauryl sulphate) | 500 | 1.24 | malaysia |
| 19- Aug | bombay air cargo | surfac (sodium lauryl sulphate) sls/bp powder | 300 | 8.37 | united kingdom |
2016
| 21-Jul 2016 | bombay air cargo | sls powder (sodium lauryl sulphate) (actual user) | 90 | 18.81 | korea |
| 20-Jul 2016 | nhavashev a sea | sodium laurylsulphate pl-ne1270-1 sles-1eo 70 pct | 2005 0 | 0.94 | thailand |
| 17- May 2016 | nhavashev a sea | sodium lauryl sulphate- | 500 | 20.73 | china |
| 15-Apr 2016 | nhavashev a sea | sles 28% ( sodium lauryl sulphate) | 2640 0 | 0.41 | malaysia |
| 11-Apr 2016 | chennai sea | rhodapex esc-70/mu (sodium lauryl sulphate) | 1600 | 3.03 | indonesi a |
| 29-Mar 2016 | bombay air cargo | surface (sodium lauryl sulphate)sls/bp powder slsbppdr 04.d.p.(qty.15 bags) | 300 | 8.95 | united kingdom |
| 19-Mar 2016 | nhavashev a sea | sles – 70 % ( sodium lauryl esthersulphate) | 6600 | 0.94 | malaysia |
Process Description
Chemical Reactions:
1) C12H25OH + SO3 → C12H25SO4H
Lauryl Sulfur Sulfated
Alcohol trioxide acid
2) C12H25SO4H + NaOH → C12H25SO4Na + H2O
Sulfated Sodium Sodium Water
acid hydroxide lauryl sulphate
Lauryl Alcohol is sulphated using Gaseous SO3 in a Falling Film Reactor. The acid Formed is highly unstable and immediately neutralized with NaOH (27.9%).
Falling Film reactor 11 is charged with reactants through lines 13 and 15 and respective inlets in the
reactor wall (not shown), the former line being for addition of Lauryl Alcohol and the latter being for charging of sulfating agent, which is gaseous sulfur trioxide. The sulfating reaction takes place in the film reactor and the product of the reaction, which will include separable waste gases, is removed from the reactor through an outlet therein and through discharge line 17, and is delivered to separator 19 wherein waste gases are removed and recycled through line 21. From the separator 19 the acid mix
produced is taken off through line 23 and is delivered to a collector 25, from which it may be pumped via line 27 and metering pump 29 through line 31, rotameter 33 and valve 35, and line 41 into wiped film reactor 45.
Temperature and pressure gauges 47 and 49, respectively, allow monitoring of the conditions of the feed and aid in calibrating the rotameter.
Feed pot 55 (which contains neutralizing solution 57), line 59, heat exchanger 61, line 63, rotameter 65, line 67, pressure control valve 69 and line 71, which enters wiped film neutralizer 45 through an inlet opening therein (not specifically shown), which is at a location above inlets(not shown) which communicate with lines 39 and 43 for addition of the detergent acid.
Coolant enters heat exchanger 61 through line 62 and exits via line 64. Pressure gauges 73 and 75 are provided, as well as temperature gauge 77, so that the pressure on the neutralizing agent in the feed pot can be determined, as can be the pressure and temperature of such agent prior to control valve 69 and prior to entrance of the neutralizing agent solution into the wiped film reactor to effect neutralization of the detergent acid. Pipes 79 and 81 communicate sight glass 83 with feed pot 55 so that the height of the neutralizing solution in the pot can be visually monitored. Make up feed of neutralizing solution 57 is stored in make-up tank 85, which communicates through passage 87, metering pump 89 and line 91 with line 59 and feed pot 57 to recharge the feed pot or to maintain the height of neutralizing solution 57 relatively constant in such pot.
Wiped film reactor 45, which is vertically cylindrical in shape, and has an interior free space or volume 101, includes a plurality of wiping blades 95, preferably three or more, depending on the size of the reactor.
Such blades or scrapers are mounted at a suitable angle, such as about 5ᵒ, on rotating shaft 97, which is coaxial with the cylindrical reactor 45, and which is driven by motor 99 (preferably a constant speed motor) in such a direction (clockwise when viewed from the top in the embodiment illustrated) that blades 95 help to move contents (not illustrated) of the neutralizer 45, with the aid of gravity, downwardly through the neutralizer (as well as outwardly onto wall 111) and into holding pot 103.
A temperature gauge 105 and a pH meter 107 are located at the bottom of reactor 45, with probes thereof (not numerically identified, but diagrammatically illustrated) in clearance space 109 between blades 95 and inner wall 111 of the reactor to allow determination of the temperature and pH of the neutralized product at the base of the wiped film reactor, from which it is being fed to holding pot 103.
A vacuum is drawn on holding pot 103, and through it also on reactor 45, by a vacuum pump or other source of vacuum, not illustrated, with which line 113 communicates. The vacuum causes Water Vapor to be withdrawn from pot 103 through line 115, condenser 117, line 119,
Sodium Lauryl Sulphate
condensate receiver 121, line 123, vacuum control valve 125 and line 113 to the vacuum pump. Condensate 127 may be withdrawn from the condensate receiver 121 through line 129, valve 131 and line 133. A pressure gauge (or vacuum gauge) 135 permits checking the operation of the vacuum controller. Coolant enters condenser 117 through line 137 and exits through line 139.
At the bottom of holding pot 103 means for withdrawing high active ingredient content neutralized detergent salt solution is provided, which includes plunging mechanism 141 in cylinder 143, which mechanism communicates with hose pump 145. Neutralized product is taken off from the holding pot through line 163, valve 165 and line 167.
The natural detergent solution from line 167 is pumped to jacketed wiped film evaporator 201. The evaporator is heated by passing steam through line 203 into jacket 205 and removing condensate from the jacket through line 207. Draft air enters the evaporator through line 209 and exits through line 211 with water vapour that has been removed from the neutralized detergent base solution.
Good contact with the reactor wall of the detergent base solution in film form is maintained by the rapid rotation of wiper blades 213, in essentially the same way such good contact is maintained with the interior wall of the neutralizing reactor employed. The dried product, in fluid form, is removed from evaporator 201 through line 215, from which it is delivered to chill roll 217, on which a film is formed due to the action of spreading roll 219. The cooled high solids content detergent, in solid film or sheet form, is removed from roll 217 by knife 221 and falls, as a solid sheet or chips, flakes or ribbons, to a collector, not shown, as represented by arrow 223.
Material Balance
Chemical Reactions:
1) C12H25OH + SO3 → C12H25SO4H
Lauryl Sulfur Sulfated
Alcohol trioxide acid
2) C12H25SO4H + NaOH → C12H25SO4Na + H2O
Sulfated Sodium Sodium Water
acid hydroxide lauryl
sulphate
| Component | Molecular Weight |
| Lauryl Alcohol | 186 |
| Sulfur trioxide | 80 |
| Sulfated acid | 266 |
| Sodium hydroxide | 40 |
| Sodium lauryl sulphate | 288 |
| Water | 18 |
| Nitrogen | 28 |
Basis: 1 ton/day of product
The product contains 95.05% Sodium lauryl sulphate, 0.8089% Lauryl alcohol, 0.1011% Sodium hydroxide and the rest water.
So,the product contains 950.5 kg SLS, 8.089 kg Alcohol, 1.011 kg NaOH and 40.4 kg Water. Conversion of Sulfated acid to Sodium lauryl sulphate is 100% as we are using excess NaOH. Material Balance on the evaporator
The evaporator has one inlet stream coming from the holding pot and two outlet streams of final product and water evaporated.
The product stream has 950.5 kg SLS, 8.089 kg Alcohol, 1.011 kg NaOH and 40.4 kg Water as shown above.
Here SLS,NaOH and Alcohol are the tie components.
So,the quantities of these in the inlet stream will remain the same ie. 950.5 kg SLS, 8.089 kg Alcohol, 1.011 kg NaOH.
The stream coming out from the neutralizer is the stream entering the evaporator.The concentrations of various components in this stream are 75.8% SLS,0.64% Alcohol,0.08% NaOH and 23.48% is water.
Therefore,water in the stream entering the evaporator = 950.5*0.2348/0.758=294.68 kg Therefore,water evaporated=294.68-40.4=254.28 kg
Material Balance on the neutralizer
The neutralizer has 2 inlet streams and two outlet streams.
The stream leaving the neutralizer which is entering the evaporator contains 950.5 kg SLS, 8.088 kg Alcohol, 1.011 kg NaOH and 294.68 kg Water.
Here Alcohol is the tie component.Therefore mass of Alcohol entering the neutralizer is 8.088 kg.
Sodium Lauryl Sulphate
According to reaction 2,1 mole acid gives 1 mole SLS.
Kmoles of SLS formed=950.5/288=3.3 Kmoles
Therefore,Kmoles of acid reacted=3.3 Kmoles
Therefore weight of acid reacted=3.3*266=877.89 kg
According to reaction 2,1 mole NaOH gives 1 mole SLS.
Kmoles of NaOH reacted=3.3 Kmoles.
Therefore weight of NaOH reacted=3.3*40+1.011=133.027 kg.
The concentration of NaOH fed to the neutralizer is 27.9%
Therefore,mass of water in NaOH solution=133.027*0.721/0.279=343.772 kg Water formed due to reaction 2=3.3*18=59.4 kg
Therefore,water evaporated(due to vacuum)=343.772+59.4-294.68=108.49 kg Material Balance on the falling film reactor
The stream containing acid and alcohol which is entering the neutralizer is the stream which is leaving the falling film reactor.
Therefore, weight of components leaving the falling film reactor are 877.89 kg acid and 8.088 kg alcohol.
According to reaction 1, 1Mole alcohol gives 1Mole acid.
Therefore, Kmoles of acid formed = 877.89/266 = 3.3Kmoles.
Therefore, Kmoles of alcohol reacted = 3.3Kmoles.
Therefore, weight of alcohol reacted = 3.3*186 = 613.8 kg.
Therefore, alcohol fed to the reactor = 613.8+8.088 = 621.951 kg.
Therefore, conversion in the Falling Film Reactor = 613.8*100/621.951 = 98.7%
Sodium Lauryl Sulphate
Mole SO3/ Mole Lauryl Alcohol = 1.1 (for optimized reaction)
Therefore, Kmoles of lauryl alcohol fed to the reactor =621.951/186 = 3.3438Kmoles.
Therefore Kmoles of SO3 fed to the reactor = 3.3438*1.1 = 3.6782 Kmoles=294.256kg According to reaction 1 stoichiometry, Kmoles of SO3 reacted = 3.3 Kmoles. Therefore, Kmoles of SO3 recycled = 3.6782-3.3 = 0.3782 Kmoles=30.256kg Fresh SO3 fed = SO3 consumed in reaction = 3.3 Kmoles=264kg
Mole SO3 / Mole N2 = 0.05
Therefore, Kmoles of N2 fed to the reactor = 3.6782*100/5 = 73.564 Kmoles=2,059.792kg Tabulation of results:
Evaporator
| Stream | Component | Mass(kg) |
| Inlet | SLS | 950.5 |
| Alcohol | 8.089 | |
| NaOH | 1.011 | |
| Water | 294.68 | |
| Outlet1 | SLS | 950.5 |
| Alcohol | 8.089 | |
| NaOH | 1.011 | |
| Water | 40.4 | |
| Outlet2 | Water 254.28 |
Sodium Lauryl Sulphate
Neutralizer
| Stream | Component | Mass(kg) |
| Inlet 1 | Sulfated acid | 877.89 |
| Alcohol | 8.088 | |
| Inlet 2 | NaOH | 133.027 |
| Water | 343.772 | |
| Outlet 1 | SLS | 950.5 |
| Alcohol | 8.089 | |
| NaOH | 1.011 | |
| Water | 294.68 | |
| Outlet 2 | Water 108.49 |
Falling Film Reactor
| Stream | Component | Mass(kg) |
| Inlet 1 | Alcohol | 621.951 |
| Inlet 2 | Sulfur trioxide | 294.256 |
| Inlet 3 | Nitrogen | 2059.792 |
| Outlet | Sulfated acid | 877.89 |
| Alcohol | 8.088 |
Sodium Lauryl Sulphate
ENERGY BALANCE
| COMPOUND | HEAT CAPACITY (J/molK) | ENTHALPY (KJ/MOL) |
| LAURYL ALCOHOL | 439.4 | -528.5 |
| SODIUM HYDROXIDE | 28.23 | -425.9 |
| SULFUR TRIOXIDE | 257.9 | -395.77 |
| SODIUM LAURYL SULFATE | 379.5 | -1329 |
| SULFATED ACID | 428.9 | -1074 |
| NITROGEN | 29.125 | |
| WATER | 75.97 | -286 |
FALLING FLIM REACTOR
INLET TEMPERATURE – 303K
OUTLET TEMPERATURE – 313K
HEAT OF REACTION
ΔHr= -321281 KJ
ΔH1= mCpΔT
=3.36*439.4*(25-30)+3.6782*257.9*(25-30)+73.564*29.12*(25-30)
=-22800.33 KJ
ΔH2=0.0434*439.5*(40-25)+0.3782*257.9*(40-25)+3.3*428.9*(40-25)
Sodium Lauryl Sulphate
=55112 KJ
(ΔH)reactor = -321281+55112-22800
= -288968 KJ
NEUTALIZER
INLET TEMPERATURE- 313K
OUTLET TEMPERATURE- 320K
ΔHr =-345819 KJ
ΔH1= macid*Cpacid*(25-40)+malc*Cpalc*(25-40)+mNaOH*CpNaoH*(30-40) +mwater*Cpwater*(30-40)
=3.3*428.9*-(15)+0.0434*439.4*(-15)+3.326*28.23*(-10)+19.098*75.97*(-10) = -36964.28 KJ
ΔH2= msls*Cpsls*(57-25)+mNaoH*CpNaoH*(57-25)+ malc*Cpalc*(57-25) +mwater*Cpwater*(57-25) +mwater*Cpwater*(40-25) +msteam*λsteam
=3.3*379.5*(32) +0.0253*28.23*(32) +0.0434*439.4(32) +16.371*75.97*(32) +5.2398*75.979*(10) +0.7872*18*2609.8
ΔH2= 123456.7 KJ
EVAPORATOR
INLET TEMPERATURE – 330K
OUTLET TEMPERATURE- 383K
ΔH= ∑Mi*Cpi*(110-57) +mwaterλwater+mwater*Cp*(10) +mwater*Cp*(100-57) =3.3*379.5*(53) +0.0253*28.23*(53) +0.0434*439.4*(53) +14.1266*75.97*(43)
Sodium Lauryl Sulphate
+14.1266*2.1*(10) +2.244*75.97*(53) ΔH=808395.8046 KJ
Q= mλ
∴ m=Q/λ
=
=357.7 kg/hr
∴ Volume of steam= 357.7/1000 =0.3577m³/hr
EQUIPMENT SIZING
FALLING FLIM REACTOR
∙ Residence Time – 5sec
∙ Kilogram of liquid handled – 0.86382 kg
∙ Density of alcohol handled – 900 kg/ m³
∙ Volume of alcohol handled – 0.0009598 m³
∙ Film thickness through which alcohol passes= 1.5mm
∙ Assuming Di:H=1:4, we get
Di=0.225m
H=0.9m
Do=0.228m
NEUTRALIZER
∙ Residence Time =5sec
∙ Kilogram of sulphated acid handled in 5 sec = x5= 1.2193kg ∙ Kilogram of alcohol handled in 5 sec= x5= 0.01124kg ∙ Kilogram of sodium hydroxide handled in 5 sec= x5=0.18476kg ∙ Kilogram of water handled in 5 sec= x5=0.4775kg ∙ Density of acid= 880kg/ m³
∙ Density of alcohol= 900kg/ m³
∙ Density of sodium hydroxide= 1920kg/ m³
∙ Density of water= 1000kg/m³
∙ Volume of liquid= = 0.0062693 m³ ∙ ∴ x 2 – *x 2 = 0.0062693m³
∙ Di= 0.329596 m
Sodium Lauryl Sulphate
∙ H =2 m
Holding Pot
Volume of product coming in will be same as that of neutralizer Volume of liquid= 0.006293 in 10 mins
∴in 5 sec volume will be= 0.752316 m³
Assume vapour space = 50%
∴ V= m³
∙ Assume D:H = 1:4
∙ * 4D= 1.5046
∙ ∴D=0.78 ; H=3.13m
Evaporator
∙ Feed inlet= 1254.28kg
∙ Feed inlet temperature= 330k
∙ B.P of feed= 861k
∙ Specific heat= 379.5J/mol k
∙ Latent heat of water= 2260 KJ/Kg
∙ Thermic fluid circulation rate= 357.7 kg/hr
∙ Volume = 357.7/1000= 0.3577 m³/hr
∙ Th1=373 K
∙ Tc1= 330K
∙ mh=0.1kg/hr
∙ mc=0.3484 kg/hr
LMTD Calculation
∙ ΔT1=100-57=43 °C
∙ ΔT2=mod (100-110) = 10°C ∙ ΔTlm= = 22.64°C
∙ U=2000 W/m² K
∙ Q=UA ΔTlm
∴A= = 0.38m² ∙ H:D=4:1
∴π*D*4D=0.38
D=0.17
Sodium Lauryl Sulphate
DETAILED DESIGN
FALLING FLIM REACTOR DESIGN
P= 1.408 atm
This is a case of vessel subjected to internal pressure Design pressure =1.1* 0.142665= 0.157N/m²
Shell thickness= t =
To find “f” we need
Yield Strength= 290 N/mm² and F.O.S= 2.5
Therefore f= = 116 N/mm²
∴ t=
= 0.1816mm
Including corrosion allowance of 2mm
t= 2.1816mm approx 3mm
Checking for thickness of 3mm for combined loading ∙ Stress in tangential direction
ft= =6.0445 N/mm²
∙ Stress in longitudinal Direction
1. Stress due to internal pressure
fl1 = = =2.983 N/mm²
2. Stress due to total weight of the vessel
Sodium Lauryl Sulphate
fl2 =
Weight= weight of vessel + weight of content = (Do²-Di²) * H* ρ + 621.951
= (0.234²-0.228²) * 0.9 * 8000 + *5
= 15.6753+0.8638
= 16.5391 kg = 162.2488 N
Actual W= 1.1*162.2488= 178.4737
∴ fl2 = π = 0.082N/mm²
3. Stress due to wind load =0 = fl3
Therefore resultant stress in longitudinal direction flr= fl1+fl2+fl3
=2.983+0.082=3.065 N/mm²
∙ Stress due to torsion
fs= =
fs= 0.0060437N/mm²
∙ Resultant Stress
fR=
= 5.235 N/mm²
Sodium Lauryl Sulphate
This is less than the permissible stress of 116 N/mm². Hence design is safe and thickness used is satisfactory. Including corrosion allowance of 2 mm.
HEAD DESIGN
We use torispherical head
th = +c
Rc =Di=228mm
Rk =0.06*228 =13.68mm
W= 0.25(3+ ) = 0.25(3+ ) = 1.77
th= = 2.27mm
FLANGE DESIGN
Let the inner diameter of the gasket
Gi= Do+10= 234+10=244mm
Go/Gi=
Go/Gi= 1.00742
Go= 1.00742* Gi = 245.81mm
Width of the gasket= (bo-bi)/2
= = 1.405mm
Basic gasket seating width= bo=N/2= 10/2= 5mm
AS bo<6.3, b=bo=5mm
bo= bi+2n= 244+20= 264mm
b= bi+N= 244+10=254mm
BELT DESIGN
Belt load under atmospheric pressure
Wm1= *G*By= π*254*5*11= 43888.05N
Bolt under operating condition
Wm2= π*g*(2b)*Mp + ( )* G *p
= 10460.92N
Wm1>Wm2, hence controlling load is Wm1.
Area of bolt required
Am= Wm1/fbolt = =318.03mm
Number of bolts= n=b/2s= = 10.16=12 (multiple of 4) Diameter of bolt=db= = 5.81mm
Bolt circle Diameter = B = bo+2db+12
=264+2*5.81+12= 287.62mm Actual bolt Spacing required=bs = πb/m= 75.3mm=80mm DESIGN OF FLANGE
K=
Wm= 43888.05 N
hb= B-G/2= 287.62-254/2=16.81mm
H= π/4 *G *p= 7955.3N
K= = 1.18
Thickness of flange= tf= G
tf=7.83mm
Outside Diameter of Flange
Dfo= B+2Db+12
= 287.62+2*5.81+12
Dfo=311.24mm
Design of Nozzle
Internal diameter of the nozzle pipe= 28.5mm Thickness required for nozzle
Trm= =
= 0.02mm
Minimum Thickness of nozzle= 0.4mm X=d or X=Di/2+t+tm-3c X=Di+2C =28.5/2+3+4-4.5 28.5+3 =16.75mm =31.5mm
X=31.5 (Choosing higher value)
h1=2.5(t-c) or h1 =2.5(tm-c)
h1= 2.5(3-1.5) h1=2.5(4-1.5)
h1=3.75mm h1=6.25mm
h1=3.75 (Choosing the smaller value)
Area removed= A= dTr= 31.5*3= 94.5 mm
Area compensated in nozzle wal, outside vessel surface
Ao= 2h1(tm-trm-c)= 19.75mm
=Ai=0 since h2=0
Ar= A-(As+A0+Ai)=31.5mm
As area Ar is positive compensation in the form of reinforcing pad is required Ar= 2(Wp*tp)
31.5=2(Wp*6)
Wp= 2.625mm=3mm
dip=do=d+2tm= 31.5+8= 39.5mm
dop= dip+ 2wp= 39.5+6= 45.5mm
Hence a reinforcing pool of inner diameter 39.5mm and outer diameter 45.5mm, with thickness 6mm can be attached.
NEUTRALIZER
Neutralizer can design as pressure vessel under vacumn
External Pressure= 101.325KN/m
Di=0.3295m ; H=2m
T=60°C ; Permissible Stress=116 N/mm ; FOS=2.5;Yield Strength=290N/mm Poisson Ratio= 0.27
Assuming Torispherical Head Rci=Do
hci= Rci-
Initially Di=Do=329.5mm
hi= 329.5-
hi= 77.84=80mm
Effective length of vessel= 2000mm+2*1/3(80)= 2055mm
Initially assume thickness = 10mm
Pc=
Pc= 12.718 N/mm
Pa=0.0386/2.5= 5.08N/mm (This is more than the required pressure) ∴Thickness= 10mm
Now, Elastic instability check
∴Pa = KE(
Now Do/L, 329.5/2055= 0.16 ∴k=0.2084 & m=2.564
Pa= 0.2084* = 5.16 N/mm
Pa= 2fc ( )*
Pa=2*116*( )*
Pa=4.1 N/mm
Pa>P for plastic Deformation
L/Do= 2000/329.5= 6.07 Do/t=329.5/10=32.9
From Appendix F= 6237=B
Pa= = 13.31kgf/cm= 1.331N/mm
Pa>P therefore Design is Safe therefore thickness 10mm AGITATOR DESIGN
Vessel Diameter=329.59mm
Internal Pressure= 0.02N/mm
Diameter of agitator= 330-(10*2)=310mm
Blade
N= 2500rpm
Width 25%of internal diameter= 329.59*0.25= 85mm Thickness:Width= 1:12 therefore thickness=329.59*0.25/12=7mm Liquid in vessel
Specific Gravity: Alcohol=0.83 gm/cm3; NaOH=1.92gm/cm3; water=1gm/cm3; Lauric acid=gm/cm3;
Mass fraction: MnaoH=0.0976; Mwater=0.2523; Macid=0.6642
Therefore average density= 1.095gm/cm3
Viscosity- μalc=0.018Pa-s; μNaoH-water=0.0033Pa-s; μlauric acid= 0.00688 Pa-s Now = ∑xi
=0.176 therefore V=5cp
Overhang=300mm
Shear stress in shaft =55N/mm
Elastic limit in tension= 246N/mm
E=1.95* N/mm
Shear Stress for key= 65 N/mm
Crushing= 130N/mm
Permissible stress for styling box= 95 N/mm
Permissible Stress for bolts= 58.7N/mm
∙ Power
Nre= *N*ρ/u
= * (2500/60) * 1095)/0.005
=8.7 *
Therefore P= Np* ρ* *
P=1* *1095* (
=226771 W
Therefore Power delivered by motor= 226771/745.7 =304.10 ∙ Shaft Design
Power= 226771 W
Torque (Tc) = 226771/(2* * )= 866Nm
Maximum Torque= 1.5*866= 1300Nm
Permissible Shear Stress= 55N/mm
Fs= (Tmax/Zp) = (1300* )/(55)
Therefore Zp== 23636
Zp=(π/16)
d=50mm(shaft diameter)
Now checking for stress in shaft
Fm=Tm/0.75R
=1300* /0.75*155
=11182N
Bending Moment(M)
M=Fm * overhang
=11182* 500=5591397Nmm
= 5591.3 N.m
Equivalent Bending Moment
=Me= 0.5(M+ )
=0.5(5591.3+ )
=5565869 N.mm
Now, shaft is cylindrical therefore Appendix A of Joshi
Z=section modulus=
f=
= 453.548 N/mm
Now, shaft is cylindrical therefore Appendix A of Joshi
Z=section modulus=
f=
= 453.548 N/mm
But permissible elastic limit =246 N/mm
Therefore increase the shaft diameter to 60mm
f=
= 262.469 N/mm
Increase the shaft diameter to 65mm therefore f= 206.439 N/mm Therefore shaft diameter= 65mm
Critical Speed Consideration
Fm =W= 11182 N
δ1= W /3EI
=
=3 mm
Impeller weight is not equal hub weight = 15kg
Therefore δ2=
Shaft weight
W= (π/4)* = 0.026kg/mm δs=
=0.0356 mm
= 0.116mm Ncritical= 1 2 s 1 26 = 542 rpm Critical Speed Consideration
Fm=W=11182 N
δ1= W /3EI
=
= 0.1051 mm
Impeller weight + Hub weight= 12 Kg
δ2=
= 1.384* mm
Shaft Weight= 0.026kg/mm
Cs=
s= 2.6979*
Ncritical= 2900rpm which is considerably more than 2500rpm Shaft diameter= 100mm
Overhang= 300mm
EVAPORATOR
P=0.101325 N/mm
Design Pressure= 1.1*0.101325= 0.1114575 N/mm Design Of Evaporator Shell thickness
t= PDi/(2fJ-P)
=
=0.346mm
Use shell thickness of 3mm including corrosion allowance Design of Shell Thickness for External Jacket Pressure Critical external Pressure
Pc=2.42E/ * Pc= 25.95 N/mm
Pa= Pc/4= 6.49 N/mm
Allowable external working pressure as per IS 2825
L/Do= 0.67
Do/t= 59.93
Therefore factor B at 373K =6700
Pa= 6700/14.22*( )= 0.770 N/mm
Since both the allowable pressure are greater than the actual design pressure, therefore the shell thickness of 3mm is satisfactory.
Design Of Jacket
Jacket shell thickness for internal pressure
trj= +c
trj=
+ 2
=2.36mm
=3mm
Use 3mm thickness for jacket shell
Jacket closer thickness should be greater of the following
tre= 2* trj= 2*3= 6mm
tre= 0.866*wj*
=0.15mm
Use jacket closer thickness of 6mm
Site Selection
Owing to the hazardous nature of the materials handled in a sulphation plant it should be accommodated in its own building at least 20m from other buildings. It should not be in the centre of the factory but on the periphery, remote from residential and other areas where gas emissions could be considered unsafe or a nuisance. The site should have easy access by road for the receipt of raw materials and should be near the powders/liquids processing plants so that long transfer lines for sulphated products (acids or pastes) can be avoided.
Lauryl Alcohol can be stored in closed cylindrical storage tanks provided that they have a water tight roof to keep out the rain. NaOH and SLS paste/pellets tanks can also be located in the open air provided that the local climate is not extreme.
The effluent treatment plant can be outside the building.
Sodium Lauryl Sulphate
COSTING OF EQUIPMENT
∙ FALLING FLIM REACTOR
Updated bore module cost = UF.BC (MPF+MF-1)
UF=Present cost index/ Base Cost Index
=602/100= 6.02
BC= 1000(
*
= 181.91$
MPF= Fm*Fp
=3.67*1=3.67
Updated Base Module Cost= 6.02*181.91(3.67+4.23-1)
=7556$ or Rs528932
∙ WIPED FLIM NEUTRALIZER
UF= 602/100= 6.02
BC= Co *
=1000(
*
=512.11$
MPF= Fm* Fp
=3.67*1
=3.67
Sodium Lauryl Sulphate
Updated Base Module Cost= 6.02*512.11(3.67+4.23-1) =21272$ orRs 1489041
∙ WIPED FLIM EVAPORATOR
UF= 602/100= 6.02
BC= Co *
=1000( *
= 111$
MPF=Fm*Fp= 3.67*1= 3.67
Updated Base Module Cost= 6.02*111(3.67+4.23-1) =4611$
=RS322769
Cost of Jacket around evaporator= 150000 Therefore total cost= 2472769
∙ Holding pot
∙ V=1.5046 or 397.473 gallons
∙ Cost= 37
=37
= 3941.5$
= Rs 275905
∙ Pump
Updated base module cost= UF*BC(MPF+MF-1)
UF=602/100= 6.02
BC =390(
=386.17$
Updated Bare Module Cost= 6.02*386.17(1.67+1.38-1) =4765$
= Rs 333600
Number of pumps used=2
Therefore total cost= 667200
Shell and Tube Condenser
Fm=2.5
Fp=0
Fo=1 (Floating Head)
MPF= 2.5(1+0)=2.5
Updated Bare Module Cost= UF*BC(MPF+MC-1) UF= 6.02
BC =300(
Updated Bare Module Cost= 6.02*295.97(2.5+4.23-1) = 10209$
=Rs 714655
Sodium Lauryl Sulphate
COSTING
COST OF EQUIPMENT
| SR NO | EQUIPMENT | QUANTITY | PRICE | ||
| 1 | FALLING FLIM REACTOR | 1 | 528932 | ||
| 2 | WIPED FLIM NEUTRALIZER | 1 | 1489041 | ||
| 3 | WIPED FLIM EVAPORATOR | 1 | 472769 | ||
| 4 | HOLDING POT | 1 | 275905 | ||
| 5 | PUMP | 2 | 667200 | ||
| 6 | CONDENSER | 1 | 714655 | ||
| 7 | NaOH STORING VESSEL | 1 | 467856 | ||
| 8 | COLD ROLLER | 1 | 100000 | ||
| 9 | GAS LIQUID SEPARATOR | 1 | 100000 | ||
| 10 | CONDENSATE | 1 | 200000 |
| HOLDING TANK | |||||
| 11 | AGITATOR COST | 2 | 600000 | ||
| 12 MOTOR COST | 2 | 1041228 |
TOTAL COST OF EQUIPMENT =6657586 Rs
ESTIMATION OF CAPITAL REQUIREMENT
A) DIRECT COST
| SR NO | COMPONENT | FACTOR(% OF EQUIPMENT COST) | TOTAL COST |
| A | DEPRECIABLE COST | ||
| 1 | EQUIPMENT INSTALLATION COST | 0.25 | 1664396.5 |
| 2 | PIPING COST | 0.35 | 2330155.1 |
| 3 ELECTRICAL COST 0.1 | 665758.6 |
Sodium Lauryl Sulphate
| 4 | INSTRUMENTATION AND CONTROL | 0.25 | 1664396.5 |
| 5 | INSULATION AND PAINTING | 0.03 | 199727.38 |
| 6 | SPARES | 0.15 | 998637.9 |
| 7 | CONSTRUCTION | 0.2 | 1331517.2 |
| 8 | YARD IMPROVEMENT | 0.02 | 133157.72 |
| 9 | TRANSPORTATION | 0.05 | 332879.3 |
| 10 | SERVICE FACILITY | 0.1 | 665758.6 |
TOTAL DEPRECIABLE DIRECT COST= 9986379 Rs
LAND COST (1092 ) = 16000000
Therefore Total Direct Cost= 25986379 Rs
B) INDIRECT COSTING
| SR NO | TOPIC | % OF DIRECT COST | TOTAL COST |
| 1 | ENGENEERING AND SUPERVISION | 0.1 | 2598637.9 |
| OVERHEAD | 0.1 | 2598637.9 | |
| SAFETY | 0.08 | 2078910.32 | |
| TOTAL | 7276186.12 |
FCI= DIRECT COST + INDIRECT COST
= 239920151 Rs
WCI= 0.18*TCI
= 0.18* (39920151/0.82)
= 8762959.976
TCI= 48683110.982 Rs
C) VARIABLE COST
| SR NO | COMPONENT | TOTAL COST/YR (Rs) |
| a | RAW MATERIAL COST | |
| 1 | LAURYL ALCOHOL | 477807636 |
| 2 | SULFUR TRIOXIDE | 116525376 |
| 3 | SODIUM HYDROXIDE | 36875084 |
TOTAL RAW MATERIAL COST
631208096
TAXES (18%) 113617457 TOTAL COST 744825553
D) UTILITY COST
| SR NO | COMPONENT | COST |
| 1 | STEAM | 173520 |
| 2 | SALARY(10% TPC) | 86627799.19 |
| 3 | PACKAGING (2% TPC) | 17325559.84 |
| 4 | DISTRIBUTION(2% TPC) | 17325559.84 |
| TOTAL COST | 866277991.9 |
Yearly Cost = 866277991.9 Rs
Yearly Sales= 7920000 Kg s
Cost/kg = 1130Rs/kg
Yearly Revenue= 894960000 Rs
Profit/ Year= 28682009 Rs
Tax on Profit= 32%
= 9178242 Rs
Therefore Net Profit= 19503766 Rs
Breakeven Capacity= 96.7%
Depreciable FCI= 39920151
Payback Period= Dep FCI/Net Profit/yr = 39920151/19503766= 2.046 yrs ROI= (Net Profit/yr)/TCI= (19503766/48683110)*100= 40%
PROCESS CONTROL REVIEW
The basic requirement of the sulphonation plant control system is to allow production of the desired quality acids and pastes in a safe manner within the design capacity limitations of the plant. The level and sophistication of instruments and process control systems is largely determined by local preference although in order to satisfy the basic requirement, as stated above, there is a minimum requirement for instrumentation, control and safety interlocks which are common to all sulphonation plants .Minimum instrumentation and control requirements
Air raising
Compressors The outlet air temperature and pressure from the compressors gives a good indication of the state of downstream process plant, where additional pressure drop may be experienced due to the entrainment of dust in the drying bed, breakdown of the catalyst or malfunction of the control valves. The gas discharge pressure and preferably also the temperature should be recorded. In addition, for safety reasons and to protect the compressor, a high-pressure switch/alarm combination should be used to stop the compressor in the event of overpressure. The sulphur pumping system must be interlocked with compressor operation, to stop the pump when no process air is available.
Pressure control system In order for the downstream control valves which control the flow-rate of SO,/air to function in their optimum range and therefore enable the SO,: organic mole ratio to be maintained as constant as possible, the air discharge pressure from the compressors must be controlled. Excess air from the compressors can be vented to atmosphere automatically through a valve controlled by the pressure measured at some point downstream of the venting point. An alternative system of controlling the compressor speed can be used where energy costs justify the additional capital expenditure.
Air coolers/chilling group The temperature of the glycol solution used to cool the process air before entering the dryers must be controlled. As an additional safeguard in the event that the temperature sensor or controller malfunctions, a low-temperature alarm, using a separate independent sensor, should be fitted on the glycol feed-line to warn if the temperature approaches O· C. The consequence of too low a glycol feed temperature to the cooling air heat exchanger is the formation of ice on the finned pipes, leading to poor heat transfer, excessive pressure drop and possibly damage to the heat exchanger or its supports. A measurement of the total air flow rate to the plant should be made on the process air directly after the chilling group. The massflow of air can be determined at this point by applying the appropriate temperature and pressure compensations to the volumetric flow-rate.
Air Driers The control of the regeneration of drying beds can be a manual or automatic operation.For automatic regeneration after fixed periods of operation, e.g. 8 hours, electromechanical (relays) or PLC based control may be used. For plants without heat recovery to produce steam, hot air from sulphur combustion and SO2/S03 cooling can be used for regeneration of the drying beds. Dewpoint meter A dewpoint meter for process air, with a recorded signal, should always be fitted as standard in sulphonation plants. Regular manual checks are essential
Film Sulphonation
Mole ratio control The effective control of mole ratio is the most important factor determining the quality of the sulphonated product. The flow-rate of SO/air is controlled by modulating valves linked to a flow sensor, normally an orifice plate. Depending on the required SO]-in-air concentration for the sulphonation of different feedstocks, it is necessary to dilute the SO] from the gasraising plant with dried process air. The central system for dilution air again employs a flow sensor and modulating valve. Accurate metering of organic material to the reactor is of critical importance. As with control of the sulphur flow-rate, proportioning pumps or gear pump/mass flowmeter combinations can be used. At present, Ballestra has installed automatic control of the S03/organic mole ratio in at least six new sulphonation plants. The principles of the mole ratio control are indicated in P&I diagram.This new development is feasible because accurate and technical reliable massflow meters are available now.
Reactor cooling system The temperature of the cooling water to the reactor must be controlled. It is normal to pump cooler water to the upper sections of the reactor, where most of the heat is produced, which therefore requires separate cooling water temperature control. The temperature of the cooling water entering and leaving the reactors should be measured and, if necessary, the flow-rates adjusted such that the T does not exceed 120 C. The flow-rate of cooling water to individual sections of the reactor and the product outlet temperature should also be measured. The consequence of ineffective cooling is poorer quality products.
Reactor emergency systems Hard-wired interlocks should be provided to prevent opening of the SO3 air isolation valve until the reactor emergency system is primed. The system should be activated by a hard-wired interlock to an organic flow sensor. Level control – acid/gas separator Control of the level in the acid/gas separator ensures an effective seal between the liquid handling parts of the sulphation plant and the exhaust gas treatment section. Several methods can be used, but the one which minimizes the hold-up and residence time distribution of acids
Neutralisation
Metering systems Sodium hydroxide or other neutralising agents, water and other solvents if required are normally added to the neutralisation loop using metering pumps. Variable-speed gear pumps controlled by mass-flow meter-based systems can be used.
pH control Closed loop control of pH is required. Where metering pumps are used for reagent addition, automatic stroke adjustment should be used to control the addition of a small fraction of the neutralising agent, the bulk of it being added by a manually adjustable metering pump.
Pressure control : The operating pressure of the neutralisation loop is normally not controlled. However, a high pressure switch must be incorporated to stop the paste recirculation pump in the event of overpressure.
Temperature control In neutralisation the temperature of the product is not controlled directly, as the feed of “too cold” water to the shell of the heat exchanger can result in the formation of a skin of semi-solid product on the inner surfaces of the tubes. The cooling water temperature is controlled instead, by the addition of cold make-up water to the cooling water recirculation system. This method of control can only be used if the heat exchanger is oversized for the maximum envisaged duty with reference to a minimum cooling water temperature in the recirculation cooling water loop of 25·C. In tropical locations, where the make-up water may be at a higher temperature than the minimum as defined for “skin” formation on the heat exchange tubes, the heat exchanger must be sized for the actual characteristics of the cooling water supply.
Process control strategy
The level of sophistication of the process control strategy is largely determined by local preference. Several options are available.
Manual control In the case of manual control, the operator follows written start-up, shut-down and product changeover procedures. During normal steady-state operation key variables are controlled automatically, usually by panel-mounted PID controllers. The operator makes adjustments to set points of the controllers and also adjusts pump stroke lengths in response to the results from plant-side analysis or in response to abnormal readings from local or panel mounted instruments. This type of control strategy is best suited to plants where long periods of steady state operation on single products are envisaged, with few, if any, product changeovers.
Assisted manual control/data logging Manual control of the operation of a sulphation plant can be supplemented by computer-based data logging. Such systems are non-interactive in that analogue and digital signals from the plant are fed to the computer/data logging system, but information is
not fed back. Consequently, the status of pumps etc. and other data can be displayed on the screen-based mimics, reports can be printed and the data obtained can be manipulated to show trends or used in other off-line computer programs.
Supervisory system Unlike simple data logging systems, supervisory control systems are designed to restrict the flexibility of the operator by “supervision” of his actions. In these systems the operator can interact with the plant through the keyboard/workstation to start or stop pumps, open valves and change PID controller set points. The three-term controllers may be conventional electronic controllers, linked to the supervising system, or software algorithms programmed into a PLC. The sophistication of the supervisory control system depends somewhat on the level of plant automation. In principle, all valves on the plant could be remotely actuated, allowing almost all procedures including start-up and shut-down to be “run” by the computer. In practice, such levels of automation are not cost-effective and a compromise is normally reached on the level of plant automation. The level of automation depends largely on site preference and a high level of automation is normally only justifiable when several products at different capacities are manufactured on a single plant. In this case it is important to ensure correct routing of feedstock to reactor and product to storage. Routing of this type can be incorporated into logic checks
within the supervisory system. Even in this case, valve automation may not be justified and manual valves fitted with proximity switches can be used to inform the system that the operator has actuated the correct valves. If automatic valves are used, however, they can be actuated automatically from sequences in the system initiated by the selection of a particular “recipe” by the operator. Such recipes may contain not only routing information but also all the information required to produce a particular product, starting from a particular feedstock. This information could be transferred to the plant either by the operator or by the system, dependent upon the level of automation. The main advantage of sophisticated supervisory control systems is that, by restricting the activities of the operator, mistakes during production which would affect safety or product quality can similarly be restricted. However, by restricting the operator’s actions, a measure of flexibility is lost in the manner in which the plant can be operated. This loss of flexibility is often important when elements in the plant are not functioning as intended. For example, if it is not possible to use the dedicated storage tank for a particular product which must be produced and an equivalent storage tank is available, then re-routing the product to the new tank not only requires valve position changes but also software changes before the system will accept the new configuration. Although most systems can be re-configured in a straightforward manner, such action is normally outside the scope of the operator’s capabilities and intervention from higher level supervisors or technicians is required. On the basis of the foregoing statements, the usual control philosophy adopted when designing a supervisory control system is as follows: a. fully automated continuous running; b. automated emergency shut-down (usually hard-wired).
a. Automated continuous running All the valves, motors, pumps and analogue loops in the process stream are controlled via a computer based system. Services and utilities are only monitored and alarmed. Quality measurements either in-line or off-line are monitored by the system. As all the necessary information is available to the computer, it can calculate and perform: material balances/consumption; conversion factors; adjustments to optimise processing; alarm on drift from pre-set operating conditions. From start-up (sulphur ignition) the plant is fully computer controlled and operated for a given (pre-set) type of product and production rate. The change of product type and/or production rate is still performed by the operator and computer assisted in terms of control and relevant process parameters.
b. Automatic emergency stop The approach is not different from the traditional control system where fail safe and plant alarm/interlocks can be brought into action at a moment’s notice so as not to endanger life or plant.
HAZARDS AND OPERABILITY REVIEW
Falling Film Reactor:
| Item | Process Parameters | Deviations (Guide Words | Possible Causes | Possible Consequences | Action Required |
| 1A | Flow | No | 1. Control valve fails (closed position) 2.Controller fails and closes valve | 1. Reaction does not take place 2. As above | 1. Select valve to fail open 2.Place controller on critical instrumentation list |
| 1B | High | 1. Control valve fails (open) 2. Controller fails and opens valve | 1. Runaway Possibility and overheating of reactor 2. As above | 1. Instruct operators and update procedures 2. See1A.2 | |
| 1C | Low | 1. Valve Incorrect opening 2. Control valve fails to respond | 1. SO3 in outlet stream will increase 2. As above | 1. See 1A.2 2. Place valve on critical instrumentation list | |
| 1D | Reverse | 1. Failure of Gas line resulting | 1. Film Breaks | 1. See 1A.2 2. Replace check |
| in backflow 2. Backflow due to high backpressure | 2. As above | valve | |||
| 1E | Later than | 1. Operator error | 1. None | 1. Production not as per capacity |
| 1F | Temperature | Low | 1. Low Lauryl Alcohol Supply | 1. Possibility of SO3 in product stream | 1.Decrease Gas Flow rate |
| 1G | High | 1. Low N2 supply | 1. Low yield of sulphated acid | 1. Install high temperature alarm |
| 1H | Pressure | Low | 1. Failure of pressure Gauge 2. Low Flowrate of Gas | 2. Film thickness will increase 2. Same as Above | 1. Replace Pressure Gauge 2. Instruct the operator and line up the pressure valve with Lauryl Alcohol |
| Controller | |||||
| 1I | High | 1. Same as 1H.1 2. High Flowrate of Gas | 1. Film Will Break resulting in increase in SO3 concentration 2. Same as Above | 1. Same as 1H.1 2. Instruct the operator and check gas flow control valve. |
References
∙ Prefeasibility report by Aarti Industries Ltd.
∙ United States Patent (4544493) by Salvatore J. Silvis, Staten Island, NY ∙ Chemical Technology Encyclopedia, Kirk Othmer
∙ Sulphonation Technology in the Detergent Industry, W Hernan deGroot
∙ Lorenz T. Biegler, Ignacio E. Grossmann, Arthur W. Westerberg, Systematic Methods of Chemical Process Design.
∙ Kiran Hari Ghadyalji, Process Equipment & Design.
∙ M. V. Joshi, Mechanical Equipment Design
∙ Analysis of Falling Film Reactors, Siu-Ming Yih, Iowa State University ∙ www.slideshare.net
Sodium Lauryl Sulphate by Chaitya Nilesh Shah, Dhwanil Trivedi, Vatsal Shah & Chaitya Shah
