Design Of A Sulfuric Acid Production Plant Engineering Essay

end Of A sulphuric stifling harvest-timeion Plant Engineering EssayThis roll is prep atomic number 18d tally to the requirements of chemical engineering department, and its too a preliminary study of sulphuric acrimonious harvestingion plant.The project begins with chapter one which includes introduction, definition of entropyic biting and shows the main economic consumptions of atomic number 16ic dot which have made it an weighty chemical in the world, followed by chapter two which talks about literature, market survey and the history and underway paradees for production the sulphuric superman also it gives small glimpse of the prices trends of the stark naked material and product.That is followed by verbal description for various mental coveres to scram sulfuric venereal infection in chapter three, which ends with the selection of the best care for which is the double inter-group communication process the description and flow sheet of the selected proces s argon discussed in chapter four.Material and energy equalizer results are listed in chapter five and the location of the plant is selected in chapter six by comparing divers(prenominal) locations, and the best location for the plant (as its set in this report) is Aqaba city. .Finally, material and energy balance details are discussed in the appendix, that includes the employ charts and references.CHAPTER ONEINTRODUCTION1.1 Definition sulfuric panelling is a strong mineral virulent with the molecular bodyula H2SO4. It is a clear, colorless, odorless, viscous liquid that is very corrosive. It is soluble in body of urine at all concentrations. Sulfuric acid has many applications, and is one of the top products of the chemical industry. on that point are another names for sulfuric acid, it is sometimes called fossil oil of vitriol.1Its chemical formula isFigure (1.1.1) Sulfuric Acid Formula11.2 Physical and Chemical propertiesThis table shows the main chemical and physical p roperties of sulfuric acidSulfuric acidIUPACOil of vitriolOther name body of water4SMolecular formula98.08 g mol1 molar(a) massClear, colorless, odorless liquidAppearances1.84 g/cm3, liquidDensity10C, 283K, 50F warming point337C, 610K, 639F boil pointMiscibleSolubility in water3Acidity(pka) barbed odorOdorNon-flammableFlash point26.7 cP (20 C)Viscosity0.3PhTable (1.2.1) physical properties11.3 Application and UsesSulfuric acid is a very important chemical commodity, and indeed, a nations sulfuric acid production is a good indicator of its industrial strength.It is utilized as electrolyte in slide by-acid batteries (accumulators) .It is important in the production of fertilizers much(prenominal)(prenominal) as ammonium sulfate (sulfate of ammonia), (NH4)2SO4, and superphosphate, Ca(H2PO4)2, which is organise when rock phosphate is treated with sulfuric acid.It is used to crawfish oxides from iron and steel before galvanising or electroplating .Concentrated sulfuric acid is us ed as a dehydrating agent, that is, to remove water, since it has a tendency to form hydrates such as H2SO4. piddle, H2SO4.2H2O.Sulfuric acid is used in the production of nitroglycerine, an inorganic ester organic nitrate, which is used as an explosive.It is used in petroleum meliorate to wash impurities out of bollix upoline and other refinery products.It is used in manufacturing of hydrochloric acid, nitric acid, phosphoric acid, ether, plastics, metal sulfates, cellophane, dyes, drugs, perfumes, disinfectants and withal glue.1This chart shows the distribution of using sulfuric acidFigure (1.3.1) Sulfuric Acid Distribution.1Specification of raw materialssulfur, S, 16Name, symbol, number32.065gmol1Standard atomic weightYellow colored lumps, crystals, powder, or formed shapeAppearancesLumps 75-115 lbs./ft3 Powder 33-80 lbs./ft3Bulk Density388.36K,115.21C,239.38FMelting point717.8K,444.6C,832.3FBoiling pointInsolubleSolubility In WaterSolidPhysical State1.819 gcm3Liquid density a t maps.Table (1.3.1) Physical Chemical Properties of Sulfur.1CHAPTER TWOLITERATURE AND securities industry SURVEY2.1 History and Current processesThe discovery of sulfuric acid is credited to the 8th century pharmacist and alchemist, Jabir ibn Hayyan (Geber). The acid was later studied by 9th century Persian physician and alchemist Ibn Zakariya al-Razi (Rhazes), who obtained the substance by ironical distillation of minerals including iron(II) sulfate heptahydrate, FeSO47H2O, and copper(II) sulfate pentahydrate, CuSO45H2O. When combusted, these compounds decompose to iron(II) oxide and copper(II) oxide, respectively, giving off water and sulfur trioxide, which combine to produce a charge solution of sulfuric acid. 1This method was popularized in Europe finished translations of Arabic and Persian treatises, as well as books by European alchemists, such as the 13th-century German Albertus Magnus.1There are two major processes (lead chamber and amour) for production of sulfuric a cid and it is available commercially in a number of grades and concentrations. The lead chamber process, the older of the two processes, is used to produce much of the acid used to make fertilizers it produces a relatively dilute acid (62%-78% H2SO4). The pertain process produces a purer, much arduous acid but requires purer raw materials and the use of expensive gas pedals. n both processes sulfur dioxide is oxidise and dissolved in water. The sulfur dioxide is obtained by zealous sulfur, by burning pyrites (iron sulphides), by roasting nonferrous sulphide ores preparatory to smelting, or by burning hydrogen sulfide gunman. Some sulfuric acid is also made from ferrous sulfate waste solutions from pickling iron and steel and from waste acid sludge from oil refineries. 12.2 Supply and DemandThis table shows the production rates of sulfuric acid (in metric tones) in some countries at different years.Production of sulfuric acid in metric tonesYear province1994199720002006France 2227224222691755Germany3380349648984595Greece360675688815Italy1228159010431616Spain2348281024183500United kingdom122512051058447Sweden5186306291010Table (2.2.1) Production Rates of Sulfuric Acid.3This table shows the production and sales amounts of sulfuric acid and the consumption rate of sulfur in Jordan from 2000 to 2005, these amounts in (ton/year).Sulfur consumption(ton/tear)Sulfuric acidYearSales(ton/year)Production(ton/year)3709254382411086052000309816466149195482001351011433071055208200226586551445961208200336430149661110289920043463454832310465402005Table (2.2.2)Jordan Production, Sales and Raw Material Consumption.52.3 Prices trends of the raw material and productThe global sulfuric acid market experienced an unprecedented rise and make out in set among fall 2007 and spring 2009. Consumption of sulfuric acid for fertilizers fell steeply in the back half of 2008 due to the collapse in the global economy. The minute half of 2009 is expected to experience close to flat to slightly positive growth, anticipating the improvement in market conditions in 2010. Trade is expected to fall globally, except for Southeast Asia, which would continue to depend on imports. As of early spring 2009, the market is go along to deteriorate as the supply shortage situation has been re outd by product oversupply in near all regions.And the world sulfuric acid supply trends are shown in the following chart.Figure (2.3.1) world Sulfuric Acid Supply.2CHAPTER THREEPROCESS SELECTION forge SelectionSulfuric acid is an important raw material used in many industrial processes, such as phosphate fertilizer production and to a much lesser extent for due north and thou fertilizers, sulfuric acid is produced by catalytic oxidation of sulfur dioxide to sulfur trioxide, which is subsequently cloaked in water to form sulfuric acid.There are no major variations of commercial interests on this mentioned chemistry. There are alternatives as to blood line of Sulfur dioxide and me thod of conversion to sulfur trioxide. The two most common methods for the conversion of sulfur dioxide to sulfuricacid are1. Lead sleeping accommodation military operation.2. Contact Process3.1 Lead Chamber ProcessThis is an old process and was introduced in Europe in near the middle of 18th century, its used to produce much of the acid used to make fertilizers it produces a- relatively dilute acid (62%-78% H2SO4).The classic lead chamber process consists of three lay outs Glover towboat, lead chambers and Guy-Lussac Tower.In this method hot sulfuric dioxide float enters the bottom of the reactor called a Glover tower where it is swear out with nitrous vitriol (sulfuric acid with nitric oxide, NO, and atomic number 7 dioxide, NO2, dissolved in it) and mixed with nitric oxide and nitrogen dioxide gases.The Glover tower serves two functions concentration of the chamber acid and stripping of nitrogen oxides from the liquid to the gas. Concentration of the chamber acid (62% to 6 8% H2SO4) is achieved by the hot gases entering the tower which gasify water from the acid.Some of the sulfur dioxide is oxidized to sulfur trioxide and dissolved in the acid wash to form tower acid or Glover acid (about 78% H2SO4). The dissolved nitrogen oxides are stripped from the acid and carried with the gas out of the Glover tower into the lead chambers.From the acid tower a mixture of gases (including sulfur dioxide and trioxide, nitrogen oxides, nitrogen, oxygen, and steam) is transferred to a lead-lined chamber where it is reacted with more water.Sulfuric acid is formed by a complex serial publication of reactions it condenses on the walls and collects on the floor of the chamber. There may be from three to twelve chambers in a series. The acid produced in the chambers, often called chamber acid or fertilizer acid, contains 62% to 68% H2SO4.After the gases have passed by the chambers they are passed into a reactor called the Gay-Lussac tower where they are washed with coo led concentrated acid (from the acid tower) the nitrogen oxides and unreacted sulfur dioxide dissolve in the acid to form the nitrous vitriol used in the acid tower. Remaining waste gases are usually carry through into the atmosphere.Product acid at a concentration of 78% H2SO4is drawn from the cooled acid stream that is circulated from the Glover tower to the Guy-Lussac tower. due north losses are made up with nitric acid which is added to the Glover tower.The major disadvantage includes the limitations in throughput, whole metre and concentration of the acid produced, also the environmental pollution.Figure (3.1.1) Typical process flow sheet for the lead Chamber.3.2 Contact ProcessBecause of economic reasons Contact plants are widely used compared to the lead plants, they are sort out according to the raw materials charged to them elemental Sulfur burning, spent sulfuric acid and hydrogen sulfide burning, and metal sulfide ores and smelter gas burning. The contributions from these plants to the total acid production are 81, 8, and 11 percent, respectively.The contact process incorporates three basic operations ( microscope stages), each of which corresponds to a distinct chemical reaction.First, elemental sulfur is received in a solid form containing various impurities. The sulfur is melted in the sulfur melter in the presence of hydrated lime which neutralizes any acidity present in the sulfur. This neutralization prevents problems of acid corrosion which would otherwise be encountered.Heat for the melting of the sulfur is supplied from steam coils. The molten sulfur is unbroken agitated to improve heat transfer, to prevent solids settling on the bottom of the sulfur confronts and to prevent a crust forming on top. The dirty sulfur is filtered to remove impurities present and after filtering is transferred to the clean sulfur pit where it is kept molten until it is pumped to the burner.Molten sulfur at a temperature of 130C is sprayed into the burner in the presence of warm, dry air. The sulfur burns, forming sulfur dioxideS + O2 SO2 H = -300 kJ mol-1The resulting sulfur dioxide is fed to a process unit called a converter, where it is catalytically oxidized to sulfur trioxide (SO3)2SO2 + O2 2SO3 H = -100 kJ mol-1Its apparent that the equation gives a abate in volume this reaction would be aided by pressure. spirited conversions are however, obtainable with catalysts at 400 to 500oC with a small excess of oxygen and the use of pressure.The available methods to maximize the physical composition of SO3As this is an exothermic process, a decrease in temperature by removal of the heat will favour the validation of SO3.Increased oxygen concentration.SO3 removal (as in the case of the double submersion process).Increased pressure.Catalyst selection, to subordinate the working temperature (equilibrium).Longer reaction time.In the contact processes, the sulfur dioxide is converted to sulfur trioxide by the use of metal oxide cata lyst, the characteristics of the used catalyst arePorous carrier having large surface area, controlled pore size of it and resistance to process gases at high temperature in pellet form if used in unyielding bed andpowdered form if used for fluidized bed. Ex- Alumina, silica gel, zeolites.Active catalytic agentPreparations are broadly speaking kept secret for the competitive reasons but they usuallyconsist of adding water soluble compounds to gels or porous substrates and firingat temperature below the sintering point.PromoterAlkali and/or metallic compounds added in trace amounts to rise the activityof the catalytic agent.A catalyst, vanadium pentoxide (V2O5) is used to increase the reaction rate because its relatively insubordinate to poisons, also because of its low initial enthronization and only 5% replacement per year. It is only effective preceding(prenominal) its melting point of 400 C. The greatest conversion of SO2 to SO3 is reached by passing the gas over some(pr enominal) catalyst beds, cooling the gas between each pass so that the reaction temperature remains between 400 and 500 C. As bath be seen the figure.The disadvantages of using the V2O5 catalyst are that it must use dilute SO2 input (7-10%), as a catalyst it is less active and requires high oxygen or sulfur dioxide to give economic conversions also it requires bigger converters and thus higher initial investment.Finally, the sulfur trioxide is absorbed in to very concentrated sulfuric acid (a 98-99 percent solution of H2SO4 in water), This operation takes place in the absorbing tower where the gas travels up through the tower, counter-current to the acid falling from the top of the tower producing a thick fuming liquid called oleum, the oleum is mixed carefully with water to avoid producing fine mist of sulfuric acid that is difficult to condense and could escape to pollute the air, the sulfur trioxide in the oleum reacts with the water as followsSO3 + H2O H2SO4 H = -200 kJ mol-1I t is clear that the reaction is exothermic and the absorbing sulfuric acid has to be cooled continuously the heat is available at a relatively low temperature and is not worth recovering.The efficiency of the absorption step is related to The H2SO4 concentration of the absorbing liquid. (98.5 99.5%).The temperature range of the liquid (normally 70 -120 0C).The technique of the acid distribution.The raw gas humidity (mist passes the absorption equipment).The mist filter.The temperature of incoming gas.The co-current or countercurrent character of the gas stream in the absorbing liquid.Main disadvantages of the contact process are that concentrated acid (98%) of high purity can be produced directly and that compact plants of quite high capacity have now become kind of common place.The contact process can be applied in different techniques three of those techniques are draw in the following sections3.2.1 Single contact / iodine absorption processAfter purification and drying, the SO2 is converted to SO3 using a series of four catalyst beds, containing alkali and V2O5. Afterwards, the SO3 is absorbed in concentrated sulfuric acid and, if necessary, an oleum absorber is installed upstream. SO3 reacts with the water contained in the absorber acid to yield H2SO4. The absorber acid is kept at the desire concentration of approximately 99% w/w by addition of water or dilute H2SO4.The adept contact/single absorption process is oecumenically used for gases with an SO2 Content from 3 6 %. New single contact plants are built only for inlet gases with substantial fluctuation of the SO2 content.The investment cost of this technique is low compared to the investment cost of double contact plants.Figure (3.2.1.1) Typical process flow sheet for a single catalysis plant.3.2.2 Double Contact/ Double tightness ProcessThe double contact process was implemented to develop the single contact/single absorption process. In this process a primary SO2 conversion of 85 95 % is a chieved in the first catalysis stage of the converter before entry into an intermediate absorber, depending on the arrangement of the converter beds and the contact time.What makes the double contact/double absorption process more advantageous is that its ability to feed gases with higher SO2 concentrations than would be practicable with the single catalysis process. Which leads to smaller gas volumes and therefore smaller equipment with comparable production capacities.This results in a considerably higher conversion rate, if the residual gas is passed through the following converter beds (usually one or two). The SO3 which is formed in the second catalysis stage is absorbed in the final absorber.In general the process uses gases with an SO2 content of 10 t o11 %. The inlet gas temperature is about 4000C. Gases with lower temperatures require reheating from 50 to 4000C. This is usually carried out with recovered heats from the conversion process.operating(a) the double contact pro cess at an upgrade pressure of 5 bar increases the conversion rate by shifting the conversion equilibrium and favouring the formation of SO3.The disadvantages are higher electricity consumption and, at the same time, less steam production. Higher nighttime emissions are caused by higher sulfur combustion temperatures (18000C), but savings of 10 -17 % on investment costs are gained.Figure 3.2.2.1 Typical process flow sheet for a sulfur burning double catalysisplant.3.2.3 ludicrous catalysis processThe unbendable catalysis process is applicable to wet SO2 gases. The potential for the formation of sulfuric acid mist might require tail gas treatment.Wet SO2 gases (eg. from the burning of H2S gases or from the catalytic conversion of H2S gases) are directly supplied into the contact tower without previous drying. SO3 formed by the catalytic conversion immediately reacts with the moisture of the gases, thereby forming the acetic acid. The sulfuric acid is condensed in a condenser insta lled after the contact tower.FactorsSulfuric Acid Production By Lead Chamber processSulfuric Acid Production By single contact/single absorption processSulfuric Acid Production By double contact/double absorption processSulfuric Acid Production By Wet Catalysis processHealth and rubber hazards involved slight safe, waste gases are fired to the atmosphere little amount of SO3 is absorbed so the rest is discharged to the atmosphereA larger amount of SO3 is absorbedA larger amount of SO3 is absorbedOperating costHigh operating costLess operatingThe least operating costLess operating costRaw materialSO2, NO, NO2, O2, H2O.Melted sulfur, O2, SO2, SO3.Melted sulfur, H2O, O2, SO2, SO3.Wet SO2 gases, H2S, O2, SO3.Waste products and by products ticktock gases are discharged to the atmosphereLarge amounts of SO2 gas are discharged to the atmosphereLess amounts of SO2 gas are discharged to the atmosphere, less heat released after each successive catalyst bed.A larger amount of SO3 is absorbed EquipmentAcid Tower (Glover Tower), Lead Chambers, Reactor (Gay-lussac Tower)Air dryer, burner, waste heat boiler, converter, single absorption column.Air dryer, burner, waste heat boiler, converter, intermediate and external absorption column.Burner, convertor, acid tower.YieldYields 78% H2SO4New plants achieve 98 to99 % conversion ratesYields about 98%Yields 70 to 80 % H2SO4environmental pollutionMore gases are discharged to the atmosphereMore gases discharged to the atmosphereLess gases discharged to the atmosphereMore gases are discharger to the atmospherePurity of productsLow purityLow purityHigh purityLow purityTable (3.2.1) Process selectionFactorsSulfuric Acid Production By Lead Chamber processSulfuric Acid Production By single contact/single absorption processSulfuric Acid Production By double contact/double absorption processSulfuric Acid Production By Wet Catalysis processHealth and safety hazards involved5553Operating cost6475Raw material6575Waste products and by product s6675Equipment7586Yield5679Environmental pollution5564Purity of products6579Total (80)46415446Table (3.2.2) Process SelectionAccording to the discussion and the data presented above we choose the Double Contact/Double Absorption process.CHAPTER FOURPROCESS DISCRIPTION4.1 Production of H2SO4 by double contact processThe process begins in the burner, in which the melt sulfur is pumped to the burner where it is burnt in an excess of dry air. The gas exiting the burner is concured at (8 9%v/v) sulfur dioxide and approximately 830C due to the heat produced by the exothermic reaction.Sulfurs on burning gives about one third of heat combustion of coal ,and this heat raises the temperature of combustion gases or so in accordance with the figure (4.1.1) as shown.Figure (4.1.1) Theoretical Flame Temperature.8This heat is high in temperature and there is plenty of it, consequently it is worth utilizing and the hot gases are led across pipes through which the water passes. The water is heat ed, steam is raised and the gases are cooled.The sulfur dioxide/air gas mixture is then passed through the stream to converter. The sulfur dioxide is converted to sulfur trioxide by reacting with oxygen over a catalyst.This reaction is described by the equation2SO2 + O2 2SO3 H = -100 kJ mol-1This reaction occurs in the converter, a four-stage reaction vessel with each stage consisting of a solid catalyst bed through which the gas is passed. The catalyst used is vanadium pentoxide (V2O5), and potassium sulphate dispersed on a silica base which forms a porous support, giving a large surface area for reaction.This reaction is exothermic and its equilibrium constant decreases with increasing temperature (Le Chatelier.s Principle).Figure (4.1.2) shows the dowery conversion of SO2 to SO3 that would be reached at an SO2 concentration of 8% v/v and a range of gas temperatures.However, the reaction rate is also temperature dependent, so that if the temperature becomes too low the equilibriu m point will not be reached.In practice, the gas temperature must be maintained between (400 500C) to maintain a high reaction rate and also high conversion equilibrium.As the reaction is exothermic, heat is generated across each of the catalyst beds. This heat must be removed between each stage to maintain the optimum reaction temperature into the following stage. The temperature rise through each catalyst bed and the inter-stage cooling is shown in Figure (4.1.2).Figure (4.1.2) The Temperature Rise Through Beds.7The gas after passing through three catalyst bed goes to the first absorption tower where the Sulfur trioxide is removed. The gas is then reheated to about 420 C, passed through the one-fourth catalyst bed, then cooled and sent to a second absorption tower.The gas mixture goes to the first and second absorption tower, a packed tower where SO3 is absorbed into a counter-current flow of 98 99% sulfuric acid.The overall reaction can be described by the following equation, where sulfur trioxide reacts with the free water to produce sulfuric acidSO3 + H2O H2SO4 H = -200 kJ mol-1The circulating sulfuric acid must be maintained at about 98% concentration and temperature is controlled in the desired rang of (70C_90C) to maximize the absorption efficiency.The acid strength is important because the drying up pressure of sulfur trioxide above sulfuric acid is at a minimum at an acid strength of 98% (see Figure (4.1. 3)).At higher concentrations the increased vapor pressure is caused by SO3 and at lower concentrations the water vapor pressure increases sharply and the resultant acid mist is not readily re-absorbed and escapes to the atmosphere. A stream of sulfuric acid is continuously bled off and cooled through a plate heat exchanger before being passed into the storage tanks.Figure (4.1.3) Relation surrounded by Vapor Pressure and Concentration.7Figure (4.1.4) Flow SheetCHAPTER FIVEENERGY AND potty BALANCE5.1 MASS BALANCE*DrierComponents sum%H201.271.3 O221.1223N269.475.7Temperature25Cpressure1 atmM1M2ComponentsAmount%H2SO439.498H2O0.82Temperature150Cpressure1 atmM3ComponentsAmount%O221.1223.3N269.476.7Temperature25Cpressure1 atmM4ComponentsAmount%H2SO439.4295H2O2.15Temperature150Cpressure1 atm*BurnerM3ComponentsAmount%O221.1223.3N269.476.7Temperature26Cpressure1 atmM5ComponentsAmount%S3.76100ComponentsAmount%SO228.1629O27.047N269.464Temperature830Cpressure1 atmM6* convertorM6ComponentsAmount%SO228.1629O27.047N269.464Temperature400Cpressure1 atmM7ComponentsAmount%O22.112N269.4466SO28.458SO324.6424Temperature450pressure1 atmM8ComponentsAmount%SO226.7226O21.691.6N269.4466.4SO326.7226Temperature450pressure1 atmM9ComponentsAmount%SO20.3146O20.07681.5N23.4766.5SO31.3626Temperature450pressure1 atmM10ComponentsAmount%SO20.3146O20.07681.5N23.4766.5SO31.3626Temperature450pressure1 atmM11ComponentsAmount%SO26.086O21.546N265.9766.5SO325.8426Temperature