Control Of Sulphur Dioxide Environmental Sciences Essay

Control Of Sulphur Dioxide environmental Sciences trySO2 is an kind of industry air pollution roughlyly from oil and char consumption , industry activities and traffics.According to research of EAP(U.S. Environmental Protection Agency) more than one C million tons southward dioxide is discharged into the atmospheric state every stratum any over the world.In the nature, about of the sulphur emissions are in the H2S(hydrogen sulphide),CS2(carbon disulphide),COS(carbonyl sulphide) and some immanent compouds.Through burning,these organics which contain sulphur section discharge the sulphur dioxide to the atmosphere,which is sufficient to kick in serious environmental problem and harm humans health.SO2 pollution whitethorn ca somatogenetic exercise plants dead in a exceedingly high speed,and is change state easily into the wind,which may bring the acid rain that may distroy the exterior buildings.The nigh importantly,high concentrated SO2 in the atmosphere is able to kill pot or cause serious ills including bronchitis, emphysema and oculoglandular conjunctivitis. that,the mhoic acid,is a lowly pollutant.When sulphur dioxide is involved in additional chemical contradictions,it squirt react with oxygen and water to sulphuric acid which is the constituent of acid rain.(NATHANSON,J.(1986))Gener solelyy,to play the serious environmental problem, on that point are two research torwards in removing sulphur dioxidepretreatment and afterwards usurping. No social function what systems lot use were all include in such two research directions.Pretreatment agent fraction the south gene from the combust mineral before it was burned. Because the main organises of south element in burn are FeS2 and organic southward, generally, in industry people often use independent ways to do separation. For the inorganic entropy including FeS2, the most handed-down way is gravitational segregation which means separate the ore containing sulfur elem ent from the coal with the differences in constriction. Such method is passing monetary and technical saucer-eyed, however its effects sometimes are limited. Because of the differentia of the coal ore all over the world, the strainaway rate of the sulfur element is highly different. In some area the gravitational segregation raft sequester nearly 90% of the sulfur element in coal ore, while in some sealed coal mines of 40% of the total sulfur depicted object tolerate be wiped by.For the organic sulfur element, it seems that there is non a efffective pretreatment approach to mould it. What people can do is just absorb the SO2 from burning organic sulfocompound. Unfortunately, because of the complicated brass instrument of organic matter, generally, the sulfur contained in the coal ore would be burned in to a series of sulfocompounds including H2S,CS2,SO,SO2 or else of only SO2.So before people assimilate the SO2, people have to alter these compounds into SO2 first. No wdays the most common way is fluidized move back.Fludized tail end is a kind of constitution for gasification of coal which is created by Fritz Winkler of Germany on December 16, 1921. Since the early 1960s, Douglas Elliott put out front that the coal should be burned instead of gasifying coal in a bubbling fluidized bed, because the it can generate steam by immersing boiler tubes. In 1982, the first CFB boiler which can burn low-grade coal was make in the Vereingte Aluminum Werke at Luenen, Germany in 1982 which is designed exclusively for the fork up of steam and heat.The general gas-solid fluidizetion has 5 major application Energy conversion, Petro-chemical processing, mineral processing, Chemical and pharmaceutical and Physical processing, and the basic one is energy conversion. protrude 1.2 Schematic of a high temperature fluidized bed gasifierIn general coal would be fed into bubbling fludized bed at 950 degree. Steam would be fed into the base of the fluidized bed thro ugh a sparge pipe-type of distri butor. therefore the coal would tolerate the hot solids in the bed and the cleaned and utilize gasification products leave the bed from the top. In this process limestone (CaCO3) and dolomite (CaCO3MgCO3) would be mixed with the coal ores to abstract the SO2 from the burning.The chemical equation is as follow(1.1)After the fluidized bed step, there is lighten approximately 20% SO2 left in the offgas. To solve this SO2, people need some technologies including Calcium-Based Reactions and Sodium-Based Reactions, which were called afterburning absorb.Until now, there is not a cut-rate and effective approach.The effective methods usually are expensive and lay a heavy burdon on finance,at the same time ,the gilded ones disable to guide the sulphur dioxide satisfactorily.The major in fakeation of this paper includes the benefits and defects of the traditional ways unconditional the SO2, the rational of the new aspect magnetic method, the problems m ay touch on and the solutions of this approach..The last purpose of the assignment is to point out a solution some(prenominal) financial and efficient. solely the experimentations and theories mentioned in this essay are establish on theories and dianoetic deductions.AnalysisAdvantagesNowdays in engineering aspect people are able to control the SO2 letting effectively, after all the steps the SO2 discharged into the atmosphere is less then 1%. Materials of these technologies are all hackneved,. Moreover, some certain technologies can get out a series of represent efficient blurb products such as vitrol and compound fertilizers.Pretreatment is shell method to control the sulfur dioxide, personally. non only because the FeS2 can be separated from the coal ore easily, but also FeS2 can be other useful stuffs in industry. Because of the characters of coal mines, the associate ore of coal is FeS2 generally. As a result the FeS2 ore occupies a magnanimous part of coal mines i n anywhere of the world, and the FeS2 ore is the most common material of puddling. So the pretreatment is a both efficient and financial approach.Fluidized bed is the sanction steps of the entirely sulfur dioxide, the absobents of fluidized bed are very cheap and common. So this technology resently is used widly in the countries which are occupying a spacious area such as China and American as a normal skill. And such technology is extraordinary suit for the large-scale factories.Afterburning entrancing is the most efficient way to control the sulfur dioxide discharging regardless of the concentration. The net consistence of SO2 in off gas which is disposed by the afterburning absorbing usually is less than 5%.In summary, the technologys resent used in the SO2 control are highly mature, however there are clam up some disadvantages can not be ignored.DisadvantagesAlthough pretreatment is the most efficient and financial method to control the sulfur dioxide, it has the deadliest defect the restriction of area. Because of the difference of the organization of coal ore in different area, such technology disables to be spreaded.For the fluidized bed the problems are secondary products and the processing ratio.When the chalks go into the boiler the active principle, CaCO3 would be resolve into CaO and CO2. The burned CO2 would sepatate out and enlarge the interspace on the CaO to form the lacunose CaO which can response with the SO2 easily. However it is impossible to make all of the CaO be the CaSO4, because the sulphating would make the interspace fullfilled by CaSO4. As a result the most chalks would not response with the SO2 and a great deal of chalks are wasted. Moreover, the secondary products are the mixture of CaSO4, CaO and CaCO3, so that the only way to manage them is dumping which may cause the salinized land.Afterburning absorbing is an efficient approach including wet limestone, wet tonic ash tree tree/caustic lime spray dryer, circulating lime reactor and sodium bicarbonate/trona injection to control the SO2,however, it also has irrefusable disadvantages the finance. After the mature two step there is a lot of SO2 in the offgas, most of which is CO2, so that afterburning absorbing usually is extremely expensive. Moreover such technology has a great deal of problems such as the corrosion on equipments, pipeline blocking and the lack of material use ratio.Discussion principlePersonally, the basic method to control the sulfur dioxide from the coal, is to separate the sulfur element from the coal ore before burning. In other words, to forbide the shaping of sulfur dioxide is the best way to control it .This kind of ideas is not impossible. If we can make most of the sulfur element separated from the coal before burned into sulfur dioxide, we do not need the afterburn aborbing.Personally people should use another aspect to think about the coal burning. The coal ore is consist of FeS2, ash content and organic organizations. Af ter the pretreatment, almost all of the FeS2 would be remove out of the coal ore, so most of the substance left is organics and ash content.In the fluidized bed, the coal would be transfor into gas, the majority of which is CO2 and sulfide gas. luckily the CO2 molecule organizationis nonpolar, and the most of sulfide gas is polar molecule, such as SO2. As we know gaseous material body and solid phase do not have the material difference, nowdays the magnetic quarter is used widely in the solid waste control. So it is possible that use the magnetic intensity in separating two kinds of gas which have differences in magnetism.Problems may meet and solutionThe biggest problem people may meet is the differences between CO2 and sulfur dioxide are too small. This kind of force is only a modest bigger than VDW(Van der Waals force), it is impossible to separate all of the CO2 and sulfide gas completely.The method to solve this problem rattling is very easy, which is magnify the differenc es of force suffered. As we know, at the same temperature and pession, the density of SO2 is bigger than that of CO2, that means the waxing velocity of CO2 is bigger than SO2. All the factories need chimneys which are used to let the off gas to swiftness atmosphere to forbid the impact on daily life. If we add a magnetic field at the bottom of the chimney, it is sure that CO2 would climb up some(prenominal) faster than SO2. That means we can magnify the differences of suffered force between SO2 and CO2.The second problem of this opinion is how to gather the SO2. In my way, it is still to use the magnetic force.The chimney in my plan is not simple one, it should the a concentric tube. There would be a lot of interspace all over the inside tube, which is used to separate the SO2 from the off gas. In the whole chimney, there would be a magnetic field, so that SO2 in the off gas would suffer the magnetic force which is able to make the SO2 psychometric test over the inside tube. The outside tube is obfurage, so that SO2 would not be discharged into the atmosphere.The last problem is finance. It seems that the technologies and skills used nowdays play a let out role in financial problems than the method mentioned above due to the high cost of basic built and daily causation consumption.Although I can not submit the compellent datas about the basic built and daily consumption, I strongly believe that it performs better on the finance than the technologies and skills used now. around skills of afterburning absorb would consume 15% electronic of the total vield for effect plant. That means only 85% power is useful. On the other hand the power consumed in establishing magnetic field is obviously much less. All the power plants in the world would have chimneys, so the basic building cost would not be unacceptable. Furthurmore the secondary product sulfur dioxide is the resource of manufacturing vitriol. In my opinion, the consumption in power even would be less than the currency earned from the secondary product.Advantages and disadvantagesIn comparison of any other technologies and skills, the supreme advantage of magnetic force is no secondary pollution. No matter what kind of skills used now have the problem of secondary pollution, such as the mixture of CaCO3 and CaSO4. These substances can not be recycled and do not have financial values, the simple managements such as landfill may cause the salinization and soil erosion. On the other side the secondary products of the magnetic method is the mixture of SO2 and CO2. This mixture is able to react with O2 under the catalysis of V2O5 to produce vitriol which can be the chemical engineering material. Furthurmore, this approach is extremely adequate for the Third World Countries. As we know, because of the financial problems the environmental problems in the Third World Countries usually are usually negelected. Controlling the sulfur dioxide is a heavy burdon on the companies and coutrie s of the Third World. If they can create frugal benefits from controlling SO2, it is obvious that there would not be any problems on the popularize in the Third World countries.However, it also has some problems the most evident one is the problem of strainaway rate. Due to the restriction of circumstance, I can not do any experiment until now, so nobody knows how much the strainaway rate is. The most urgent and effective solution is doing experiments. Any priceless and successful technologies and skills are based on doing a mass of experiment to find problems and change the process. Moreover it seems that to reach the target mentioned above, there would be a simple but endless process, that means it is only suitable to the sweeping factories.ConclusionIn conclusion, the way that author put front obviously is a new aspect to regard the control of sulfur dioxide. After more than 100 years research on the traditional methods, they are all extremely ripe and difficult to improve. T he magenic approach has the innate superiorities in comparision of the traditional ways. It is a definit physical technology which means there would not be any new extra pllutant to harm the environment. Moreover compared with the other new methods researched now, it is incredible convinient. All the basic building can be remaked from the existing equipments such as chimney and fluidized bed. In evolution countries such as China and Africa countries which are not willing to establish attention on the environmenal security, this technology can improve their enthusiasm, because they can gain a high economical benefits from the secondary products vitrial with only a little investment. Although there are still some undeniable problems on this magenic way, it moldiness be a valuable toward to research.The method mentioned in this paper is based on the 4 years experience in studying environmental subject of the author. Although the perspective and theoretical knowledge are sometimes u ninitiate and idealize, I strongly believe that this method must be valuable. Not only because the method itself, but also the aspect to deliberate and research. Environmental science is a wide ranged major which is not restricted in chemistry or biology, but also physics, physical chemistry, manage and biochemistry. The workers of defend environment should expanse their own field of vision to all the relational knowledge instead of the major itself. In this career, not matter the organizations and physical properties, not matter the fields people consentrate on, as environment protection workers, we can all learn a lot of things and acquire eagerness from the whole science and engineering region.