PRODUCTION OPERATIONS & MANUFACTURING PROCESSES OF LABSA Essay

Sulphonation The ProcessMost electrophilic substitution receptions be irreversible but sulfonation is an exception. discussion of benzene with oleum (a solution of SO3 in concentrated sulfuric harsh) testament give the sulfonic panelling, the electrophilic species macrocosm sulfur trioxide which is Lewis acidic. image 1 Sulphonation Benzene equationThe sulfonic acid smoke be converted back by treatment with blue aqueous acid. The reason for this reversibility is the fact that the Wheland intermediate is overall neutral and therefore more stable than other, positively charged intermediates. Hence, under forcing reaction conditions, the energy disagreement in progressing in either the forward or backward sense from the Wheland intermediate is proportionately smaller comp bed to the barrier to activation and hence discrimination is lost. anatomy 2 Progress of Reaction against EnergyThis makes the SO3H a useful directing group if it is desired to carry our selective ortho substitution of a monosubstituted benzene possessing an ortho/ space-reflection symmetry activating group. Under normal circumstances, para substitution would dominate, despite the statistical favouring of the ortho positions out-of-pocket to steric hindrance of the original substituent. Initial sulfonation para gives a Disubstituted benzene in which both substituents direct to the same position. Subsequent directed electrophilic substitution and removal of the sulfonic acid group gives theortho disubstituted convergence.Process Involved In the Manufacture of research labSAFig 3 F diminishedchart of the process behind the merchandiseion of LABSA.The manufacturing of LABSA at Sasol gulf is a continuous process. An interval of 1 day after a period of 20-21 age for the aim of shut-down and start-up is essential for maintenance purposes. The key reactions involved in the formation of LABSA argon as followsAir Drying second Melting Ignition of siemens (S) to randomness dioxide (SO2) SO3 harvest-timeion Oxidation of sulphur dioxide to sulphur trioxide (SO3) using catalyst vanadium pentoxide (V2O5) under optimum temperature. Film Sulphonation Reaction of Linear Alkyl Benzene (LAB) with due south trioxide to yield the end product LABSA. Ageing & HydrolysisGas Separation & Gas Scrubbing Separation of LABSA from unreacted bunglees.Air DryingThe denude taken from outside is compressed and dehumidified by means of the following units1)Intermediate Cooling Unit.2)Silica gel Dehumidifying Tower.The simmer downing has the purpose to remove the humidity from the commit, up to a saturation humidity of 2 score Celsius & in all case to convey low temperature ambience to the dehumidifying tower, thus favoring the piddle absorption in the silica gel. The silica gel air ironicaling has the object to reduce to very low values (dew foreland -60 approx.) the moisture content of air intended for the sulfur combustion, & past for conversion.This reduces to acce ptable values the oleum criterion produced in the conversion unit, which depends directly to the quantity of body of water contained in the air.WorkingThe air filtered is sucked by the compressor that sends the process air to the refrigerating group. This unit removes the compression oestrus by water & moreover cools the air to 2 degree Celsius by means of the intermediate medium cooling unit which is kept at constant temperature. The equipment for air drying is a vertical cylindrical vessel, which is horizontally divided in two parts by a partition containing insulating clobber. The two silica gel layers are placed on nets 2 spaces are left free above and below such layers for air inlet and outlet respectively. On the plates, at the level of both silica gel layer, two light glasses are located to check visually their conditions. Some silica gel indicator is placed near the sight glasses, changing its chroma accordingto the quantity of absorbed water thus saturating with water , it changes blue to pink.Fig 4 Boiler to produce and supply steam.Characteristics of Silica GelAppearance white color, granules of 3-6 mm approx.Bulk Density 700kg/dm3 approxThe regeneration is carried out by stir uping with air at 150 degree Celsius. A checking about the effective regeneration is make by verifying the Silica gel indicator through the sight glasses, as well as by verifying the outlet temp., of the regeneration air on the recording thermometer. When the regeneration is accomplished the silica gel band has a temperature quite near 150 degree Celsius. Therefore it is inevitable to cool the silica gel thus allowing it to adsorb the humidity of the air crossing it.Note The four way valves are provided with a drive by pneumatic cylinders which are remote controlled energizing some solenoid valve suitably.Air drying and coolingAir that is utilized in the production of LABSA has to be cooled commencement ceremony and then dried to pick up its feasibility for furthe r reactions. Air is cooled by modernizeing it through a heat exchanger containing the coolant mono-ethylene glycol at a temperature of 0 to -2 degree Celsius. The coolant manipulates concretion of air to around 5 degree Celsius.After cooling air to the required temperature it has to be dried to remove traces of moisture present in it. For this purpose air is passed through a cylinder filled with silica gel. The silica-gel puzzle outs the dew point of the water in the air down to stay -40 degrees Celsius. This means that the air is dry as if the air was cooled down to -40 degrees Celsius. In practice two cylinders with silica-gel are used one for drying the air, the other is reconditioned. In general the changing of the cylinders is done automatically.Fig 5 Air Drying ProcessFig 6 Glycol TowerIn order to remove the compression heat and to condense the moisture, the air is archetypical cooled by cooling water and then by a glycol solution in the glycol tower. The air flow is th en conveyed at a constant temperature (less than 5) to the silica gel dryers.Sulphur MeltingSulphur is melted to allow Sulphur that has been acquired has to be melted prior to its ignition. This is done by heating it in the melter at temperatures of one hundred thirty-five to 145. If the temperature exceeds 145 it would result in vaporisation of sulphur while temperatures less than 135 would be inadequate to melt sulphur. Therefore a temperature of 140 is maintained to prevent wastage of sulphur due to the above mentioned causes.Fig 7Sulphur Melting Tank.The solid sulphur is melted and filtered to avoid the pump valves clogging and then fed to the sulphur burner by a proportioning pump. The viscosity of molten sulphur is minimum between 135 to 140 .Fig 8 Viscosity Of SulphurMolten sulphur is fed under mass control by means of a mass flow meter. The pump and the relevant piping are steam heated in order to to keep thetemperature constant and to minimize sulphur viscosity.Fig 9 Su lphur BurningSO ProductionThe oxidation reaction of sulphur dioxide and trioxide is exothermic and heat produced by it is quite sufficient to keep the catalyst layers at the required at the required temp. to obtain a good conversion progress. In order to get the best efficiency, the gas inlet temperature in the first catalyst layer has to be about 420 degree Celsius.To start the reaction, the catalyst layers of the first & second stage of the conversion tower have to be brought to the necessary temperature. This is reached by preheating with hot air and the upper part of the catalyst tower is heated upto a temperature of 400-420 degree Celsius.Fig 10 Catalyst BedSulphur Dioxide & Sulphur Trioxide ProductionThe sulphur combustion furnace has been designed for this special purpose. In the furnace, the sulphur is fed through a pipe and falls on a surface of refractory balls, while the combustion air is supplied in counter current, thus obtaining the complete combustion of sulphur with out its spraying through a nib which might often clog owing to sulphur impurities.This dodge is quite simple it does not require any(prenominal) maintenance and the gas composition does not change. The temperature of the gas at the burner outlet is around 700 degree Celsius (corresponding approximately to a SO2 concentration of 7% by volume). Thereafter a heat exchanger cools the gas so that it reaches the conversion tower at the required temperature. The conversion tower is composed of three layers of vanadium pentoxide (V2O5) catalyst. The gas, passing from a layer to next one, crosses a heat exchanger to take the gas temperature to optimum conversion values on every stage. In order to allow quick startup, a preheating system has beenprovided. The main characteristics of Ballestra pre-heating system have been provided No electric pre-heater is required because if it were used, being in the presence of SO3, it would be corroded very quickly. Moreover, with Ballestra system there is no need to either cut off or regulate values in the circuit of conversion lines, which should operate a temperature of about 500 degree Celsius in the presence SO2 / SO3, thus being easily corroded. The gas temperature is of course too high to be suitable for sulphonation therefore some heat exchangers in the series are used to cool the gas down to proper sulphonation temperature. The hot air glide slope from SO3 coolers is utilized for silica gel regeneration.6 Fig 11 SO2 / SO3 ProductionFilm SulphonationThis group is composed by a film nuclear reactor, multi-tube type, having dimensions and number of tubes proportional to the plant capacity. The sulphonation gas is automatically fed on the reactor top and distributed in part strictly equal on each of the pipes composing the reactor. The raw material to be sulphonated is fed in co-current with the gas. Outside the reaction tubes in the reactor jacket the cooling water circulates in co-current with the film, thus allowing a co ntrol of the reaction temperature by heat removing.The distribution of the gas and the product to be sulphonated is designed in order to ensure a constant ratio between the two phases, inside each reaction tube. The sulphonated or sulphated product, coming out of the reactor is suitably degassed, aged and stabilized according to the fed raw material and fed to the neutralization unit.In this connection the Ballestra sulphonation / sulphation system by film reactor has great advantages towards the other existing systems on the market since in the case of power failure an emergency system, included in the supply, avoids any damage to the product and the necessity of cleaning the reactor before resuming operation. This system can be also used during plant startup the material to be sulphonated is fed and recycled to the reactor until optimum SO2-SO3 conversion is reached.Main reactorFig 12 Top view of the Reactor Fig 13 Bottom Nozzles Of the ReactorThis SO3 is sent to the reactor wh ere it reacts with Linear Alkyl Benzene. Due to presence of some water vapours in air some oleum is also formed. This should be avoided as it can cause blockage. The reactor has small tubes in which the SO3 passes and the LAB passes through its sides. The main reaction takes place at perforate of these tubes and during maintenance these tubes are soundly cleaned because if the LAB leaks to the centre part then the reaction testament take place there only and no SO3 will pass through.Then this variety of LABSA (desired product), LAB, SO3 and a mixture of other waste materials including oleum is sent to a separator. The liquid product is sent to the aging vessel and the gases are sent to cyclone.Fig 14 Sulphonation Plant ArrangementAgeing & HydrolysisThis is used to stabilize the sulphonated DDB. It is composed by an ageing unit and stabilizer. The product after being sulphonated overflows into the bottom of the ageing unit. It is then conveyed into the stabilizer together with w ater. Afterwards it is transferred with the help of a pump to the neutralization unit.Fig 15 Ageing VesselGas SeperationCyclonic separation is a method of removing particulate matters from an air (or gas) shoot, without the use of filters, through vortex separation. Rotational effects and gravity are used to separate mixtures of solids and fluids. present a high look sharp rotating air-flow is established within a cylindrical or conical container called a cyclone. Air flows in a spiral pattern, beginning at the top (wide end) of the cyclone and shutdown at the bottom (narrow) end before exiting the cyclone in a straight stream through the center of the cyclone and out the top.Larger (denser) particles in the rotating air stream have too much inertia to follow the tight curve of the air stream and strike the outside wall, falling then to the bottom of the cyclone where they can be removed. In a conical system, as the rotating air-flow moves towards the narrow end of the cyclone t he rotational radius of the air stream is reduced, separating smaller and smaller particles from the stream. The cyclone geometry, together with air flow rate, defines the cut point of the cyclone.This is the size of particle that will be removed from the air stream with a 50% efficiency. Particles larger than the cut point will be removed with a greater efficiency and smaller particles with a lower efficiency. The liquid product and reactants which still have to react are sent to the aging vessel but the product in the form of vapour and gases are sent to Electrostatic precipitator.Fig 16 Gas divideGas Scrubbing / Exhaust Gas TreatmentThe unit is designed to treat exhaust gas stream coming from the sulphonation reactor before being sent to the atmosphere in order to remove any possible organic, unreacted SO traces and unconverted SO. The exhausted gas coming from the reactor pass through a cyclone which provides to separate the acid mist before getting into the electrostatic prec ipitator and SO2 scrubber column.Fig 17 Exhaust Gas TreatmentIn the electrostatic precipitator the organic substances and unreacted SO3 are separated and eliminated. The residual unconverted SO2 is absorbed in the scrubbing column in which a water and caustic soda solution is continuously recycled. The gas stream is contacted with a controlled stream of fresh organic raw material.Fig 18 Electrostatic Precipitator Functionality DetailsFig 19 Electro Static Precipitator Construction DetailsAn electrostatic precipitator (ESP) or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. The LABSA is separated and sent to the ageing vessel.Types of Heat Exchangers graduated table and furnish heat exchangerShell and tube heat exchangers consist of a series of tubes. One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the t ubes that are being heated or cooled so that it can either provide the heat or absorb the heat required. A set of tubes is called the tube bundle and can be made up of several types of tubes plain, longitudinally finned etc. Shell and Tube heat exchangers are typically used for high pressure applications (with pressures greater than 30 bar and temperatures greater than 260C. This is because the shell and tube heat exchangers are rich due to their shape. There are several thermal design features that are to be taken into account when designing the tubes in the shell and tube heat exchangers. These includeTube diameter Using a small tube diameter makes the heat exchanger both economical and compact. However, it is more likely for the heat exchanger to foul up faster and the small size makes mechanical cleaning of the fouling difficult. To prevail over the fouling and cleaning problems, larger tubediameters can be used. Thus to determine the tube diameter, the available space, cost an d the fouling nature of the fluids must be considered.Tube thickness The thickness of the wall of the tubes is usually set to ensure oThere is enough room for corrosionoThat flow-induced vibration has resistanceoAxial strengthoAbility to easily stock spare parts cost Sometimes the wall thickness is determined by the easy layimum pressure differential across the wall.Tube length heat exchangers are usually cheaper when they have a smaller shell diameter and a long tube length. Thus, typically there is an aim to make the heat exchanger as long as possible. However, there are umpteen limitations for this, including the space available at the site where it is going to be used and the need to ensure that there are tubes available in lengths that are twice the required length (so that the tubes can be withdrawn and replaced). Also, it has to be remembered that lone, thin tubes are difficult to take out and replace. Tube pitch when designing the tubes, it is unimaginative to ensure tha t the tube pitch (i.e. the centre-centre distance of adjoining tubes) is not less than 1.25 times the tubes outside diameterLAS/LABSA ( Linear Alkyl Benzene Suplhonic cutting ) The ProductDescription of LASLinear alkylbenzene sulfonic acid is the largest-volume synthetic surfactant because of its relatively low cost, good performance, the fact that it can be dried to a stable powderize and the biodegradable environmental friendliness as it has straight chain. LAS is an anionic surfactants with molecules characterized by a hy purgehobic and a hydrophilic group. Alpha-olefin sulfonates (AOS) alkyl sulfates (AS) are also examples of mercantile anionic surfactants. They are nonvolatile compounds produced by sulfonation. LAS are complex mixtures of homologues of different alkyl chain lengths (C10 to C13 or C14) and phenyl positional isomers of 2 to 5-phenyl in proportionsdictated by the starting materials and reaction conditions, each containing an aromatic ring sulfonated at the par a position and attached to a linear alkyl chain at any position with the exception of terminal one (1-phenyl). The properties of LAS differ in physical and chemical properties according to the alkyl chain length, resulting in formulations for non-homogeneous applications. The starting material LAB (linear alkylbenzene) is produced by the alkylation of benzene with n-paraffins in the presence of hydrogen fluoride (HF) or aluminium chloride (AlCl3) as a catalyst. LAS is produced by the sulfonation of LAB with oleum in batch reactors. some other sulfonation alternative reagents are sulfuric acid, diluted sulfur trioxide, chlorosulfonic acid and sulfamic acid on falling film reactors. LAS are then neutralized to the desired table salt (sodium, ammonium, calcium, potassium, and triethanolamine salts). Surfactants are widely used in the industry needed to improve contact between polar and non-polar media such as between oil and water or between water and minerals.MASS DENSITY AT 20 DEG REES C 1.070 g/cm3 VISCOSITY AT 20 DEGREES C 1500 2000 mPa.s.MELTING say 10 DEGREES C.BOILING POINT 315 DEGREES C.VAPOUR PRESSURE at 20 DEGREES c Below 0.15 (0.001 mm Hg). FLASH POINT (PMcc) 200 DEGREES C.DECOMPOSITION TEMPERATURE 100 DEGREES C.Ph 2.Applications of LASAlkylbenzene sulfonic acid, as the raw material of detergent, is used to produce alkylbenzene sulfonic acid sodium (LAS), which has the performances of cleaning, wetting, foaming, emulsifying and dispersing, etc. The rate of biodegradation is more than 90%. The product is widely used for producing various detergents and emulsifiers for agricultural herbicides and in emulsion polymerization. It is mainly used to produce household detergents such as washing powder, detergent of dishware, detergent of light or bad dirt, cleaner of textile industry, dyeing assistant, degreaser of platingand leather making industry, and the deinking agent of paper-making industry, etc.CharacteristicsGood Surface active pro pertiesLow cost surfactant for detergents scant(p) processing into dried powdersDesirable solubility in both liquid and powder formulation BiodegradableCompatible with other surface active agentsgross revenue SpecificationsAPPEARANCEViscous Light Brown liquidACTIVE MATTER96.0% minACID VALUE180 190FREE OIL1.5% maxWATER1.0% maxCOLOR, KLETTE50 max (5% Sol. pH=7, 40mm cell)FREE SULFURIC ACID1.5% maxAdvantagesCost effective, anionic surfactant.Biodegradable.Due to its stable foam, suitable for detergent applications in combination with other surfactants. Compatible with enzymes and builders.Outstanding performance with other anionic surfactants due to its synergistic effect. Consumes less alkali for neutralisation.Ideal for liquid detergent application due to high solubility and low salt content.Packaging & TransportationLABFirst the truck is parked in the heavy stretch outing station directly under a valve. Laborers enter the truck and fix metal rods in grooves near the door. Then a c ardboard perimeter is set up in order to provide support. A flexi-bag is spread out on the bottom of the container, above and within the cardboard perimeter. A hose is connected to the valve and to the flexi-bag. The initial reading is taken from the main LAB store. The flexi-bag can withstand 20-25 tons of LAB. Calculations are carried out to transfer an approx. 20 tons. The meter reading must reduce by 52cm.Fig 20 Flexi Bags within cardboard perimeterSulphonic AcidThe sulphonic acid is corrosive in nature and therefore requires a vehicle with a pre-fitted tanker. The tanker is made of a special material (commonly stainless steel) Also the tank must be able to keep the sulphonic acid at a desirable temperature.Fig 21 Fitted TankLABSALABSA is packaged into plastic drums and then transported. severally drum contains 210kg of the product. Sasol buys second hand drums in order to cut costs. Once the drums are loaded with LABSA on a wooden platform a forklift will move them to the s torage shed. At the time of loading the forklift will carry these drums to a loading station with an adjustable ramp. The forklift will carry the containers into the truck and load them there.Fig 22 Plastic Drums for packagingAnalysisEvery two hours, regular analysis of the product is carried out to make sure the quality of the product is maintained. A sample of the product is takenin a beaker and taken to the analysis room.Color Klett DeterminationA Klett colorimeter allows light to pass through and determines the colour Klett of the substance. The beaker is put on the colorimeter and the value of the color Klett is obtained. Lesser the color Klett, better the quality of the product. The standard value for Klett is around 50%(maximum). Here at Sasol, it ranges from 5-10% and is therefore great in quality.Required EquipmentsKlett tintometerBlue Filter No. 42 with 400-465mm wavelength rangePair of cells with 40mm path length equalizerRequired ReagentsEthanol 99.9% GPRMethanol GPRPro pan-2-ol ( Isopropyl alcohol ) GPRDistilled water partPrepare solvent of ethanol 99.99%, methanol, propan-2-ol or distilled water or a mix of all. look 5g of active substance and dilute with a weighed amount of solvent so that a solution of 5% m/m is prepared for color measurement.In case of 5% m/n color measurement , weigh 5g of active substance, then times the volume of solvent required by relevant solvent density and weigh solvent.Mix upto complete dissolution.Fill 40mm path length cell (clean and dry) with mixture and other cell as reference cell. Colorimeter must be switched on 15 mins prior to thetest.Acid value determinationAfter finding the color Klett, the sample of the product is then titrated with ethanol, drop by drop after adding the indicator. Through this, the amount of ethanol required to reach the n point is noted and the acid level of the product is calculated. It should be approx. 180. If the acid value is higher or lower than the required value, the air flow rate is adjusted and analysis is carried out till the desired acid value is obtained.Required equipments250ml conical flask10ml BuretteLab analytic balance reading upto 3 decimal placesRequired ReagentsDistilled waterSodium hydroxide Volumetric SolutionPhenolphthaleinEthanolThis method covers determination of acid value for sulphonic acid, however it can also be used for pure fatty acids.ProcedureWeigh accurately about 2g of sulphonic acid into the conical flask and note the weight. Add 25ml of ethanol and mix well to ensure the sample is dissolved completely. measure with NaOH solution using phenolphthalein until the solution retains a faint pink colour. Note T1.CalculationAcid Value = ( T1 x Molarity of NaOH x 56.1 ) / WtFree Acid % = ( T1 x Molarity of NaOH x titrated acid molecular weight ) 10ConclusionIn a nutshell, the previous month at Sasol has been very productive in terms of the knowledge gained regarding the manufacturing operations of the LABSA plant in Dubai, UAE.Future Sc opeThis is a detailed report on Production Operations and Manufacturing Processes of LABSA. It is highly edifying on processes such as Air Drying, SO Production, SO Treatment, Linear Alkyl Benzene Sulphonation etc. The report can be used to bring about the following functionalitySet up companiesSet up detergent raw material supplyImprove plant production quality repress production costsReferences1 www.wikipedia.com2 www.sasol.com3 www.uaeincorp.com4 www.users.ox.ac.uk5 Sasol Gulf Operation Manual6 Sulphonation Technology in the Detergent Industry by W. Herman de Groot 7 www.lasinfo.org8 www.mixmedicine.com9 www.chemicalland21.com10 Test Method Control Room lodge