VAMPIRE SOCIAL FEAR Essay Example | Topics and Well Written Essays - 1250 words

VAMPIRE SOCIAL FEAR - Essay Example The concept of the existence of vampires was further glorified by eminent classic and contemporary literature authors that have created frenzy amongst the masses regarding the existence of these creatures. (Belanger, 2005, p. 49) As mentioned earlier, on a literary front the idea of vampires have fascinated, amazed and scared people throughout the ages. The belief in the existence of demons and spirits has been a prime aspect of all faiths and are often deemed to be the forerunners of the creation and concept of vampires; a dead blood-sucking nocturnal being that is largely associated with evil and the damned. Roman, Greek and Mesopotamian cultures all had a common notion regarding the existence of vampires but the concept itself gained more shape in Eastern Europe, where the legends narrated that vampires were revenants of sinner, suicide victims, people involved in witchcraft and corpses under the possession of malicious spirits or people who died of vampire bites. There were count less speculation regarding the appearance of vampires and before human physical features were used to typify Vampires, they were vastly believed to bestial creatures, which were damned for the rest of eternity and their existence was only meant to plague the living. The Description of the appearance of vampires is illustrated immaculately by the following quote from Sacred Hunger authored by Michelle Belanger, a self-proclaimed Psychic-vampire, who has published several books on this entire concept and has demonstrated the contrasts between the media portrayal and folkloric image of vampires, she states, â€Å"The vampire has come a long way since its beginnings in folklores†¦ Though, monstrosity in their hungers there is an ineffable something that inspires their so-called ‘Victims’ to willingly open their veins. Yet in stark contrast, the vampires we encounter in the tales of Eastern Europe are little more than corpses. These foul and bestial monsters terrorize whole villages, filing their victims with horror and disgust.†(Belanger, 2005, p. 14) Therefore, from the aforementioned quote it is abundantly clear that there is a huge schism between the perception of vampires in contemporary and the portrayal of folklores. Belanger has defined the true meaning of vampirism and the prevalence of this belief in gothic sub-cultures. It has become more of an identity for people and the term ‘vampirism’ itself is not used to signify bestial behavior or monstrosity, and is now given similar connotations as people who are left-handed; the latter due to the widespread belief that left-handed people are evil. The aforementioned analogy describes that vampirism is no longer emblematic of a blood-thirsty creature but all those people who are in pursuit of vital energy. However, this is still a subjective approach to the subject and having mentioned the prose will focus its attention back to the area under discussion that is whether or no t the social fear derived from these creatures is in anyway valid and the amount of insight provided by literature and conception of fictional characters to demonstrate this aspect. Therefore, the substance of the following prose will juxtapose the folkloric illustration of these creatures and how authors have portrayed the image of these creatures. In order to gain greater amount of insight in to the subject, the prose will

Comparative paper examining some aspect of the legal regime governing Essay

Comparative paper examining some aspect of the legal regime governing media in Hong Kong and in the United States - Essay Example Under this principle, the media are the voice of the ruling Party and play by its rules and policies. Apart from that, the Party controls all activities of the media that pertains to news production and delivery to the public. Thus, the media only delivers what is authorized by the Party to the public. On the contrary, in America, the media operates freely with minimal interference from the government. Additionally, the media functions as a â€Å"watchdog,† which evaluates and monitors the actions and activities of the government. Defamation laws in these two countries clearly bring out the differences and similarities in media activities and regulations in America and China. Defamation in law is the act of making statements about a person, which damages the reputation of the individual in question. When in written format, defamation is referred to as â€Å"libel† and â€Å"slander† when in spoken form. In order to understand how defamation law works in China, it is essential to explore the structure and function of the legal system in China as it pertains to matters of the media. Thus, the first section of this paper will explore the legal system in China while drawing on any similarities and differences with the United States legal system. The second section will look at the background of defamation law in the United States and Chinese, and finally, the last section will draw on comparison between defamation law in China and the United States. This provision is similar to what is found in the United States Constitution, and at first, one may think that the Chinese media enjoys the same rights as that in America. However, application of the Chinese Constitution is different from that of the United States constitution. Unlike the Americans, citizens of China enjoy neither economic nor civil rights enjoyed by their American counterparts. This ineffectiveness in the application of the Constitution in China is because of the

SONG love for sale by miles davis Essay Example | Topics and Well Written Essays - 250 words

SONG love for sale by miles davis - Essay Example hat take this form last nearly 4 minutes with a diminishing common tone and tri tone substitutions particularly between the fifth and seventh major and minor. Notably, this is described by A1-A2-B-A3. It is these changes between the majors and minors that lead to solo breaks in the song and such sections lust for nearly 30 seconds. This song is slightly different from other Jazz song despite being classified under the same song types. The difference lies mainly in the tonality where the Love for Sale takes â€Å"A† sections that are nearly 50/50 between the minor and major while â€Å"B† major primarily. Additionally, the song takes a slight different in its movement where it seems to employ skips and steps in both direction and these apply on a wide range on a fifth and an octave; however, the same does not take large leaps. Finally, it is worth noting that the song has three choruses that harmonizes and blends to the entire song. Notably, at (Davis) 04:20 and 06:40 minutes, Davis applies swings and vocals comping techniques with progressive chording. This makes this song from other bebop groups that only have one chorus throughout the

Comparative paper examining some aspect of the legal regime governing Essay

Comparative paper examining some aspect of the legal regime governing media in Hong Kong and in the United States - Essay Example Under this principle, the media are the voice of the ruling Party and play by its rules and policies. Apart from that, the Party controls all activities of the media that pertains to news production and delivery to the public. Thus, the media only delivers what is authorized by the Party to the public. On the contrary, in America, the media operates freely with minimal interference from the government. Additionally, the media functions as a â€Å"watchdog,† which evaluates and monitors the actions and activities of the government. Defamation laws in these two countries clearly bring out the differences and similarities in media activities and regulations in America and China. Defamation in law is the act of making statements about a person, which damages the reputation of the individual in question. When in written format, defamation is referred to as â€Å"libel† and â€Å"slander† when in spoken form. In order to understand how defamation law works in China, it is essential to explore the structure and function of the legal system in China as it pertains to matters of the media. Thus, the first section of this paper will explore the legal system in China while drawing on any similarities and differences with the United States legal system. The second section will look at the background of defamation law in the United States and Chinese, and finally, the last section will draw on comparison between defamation law in China and the United States. This provision is similar to what is found in the United States Constitution, and at first, one may think that the Chinese media enjoys the same rights as that in America. However, application of the Chinese Constitution is different from that of the United States constitution. Unlike the Americans, citizens of China enjoy neither economic nor civil rights enjoyed by their American counterparts. This ineffectiveness in the application of the Constitution in China is because of the

Music and Social Change Research Paper Example | Topics and Well Written Essays - 1250 words

Music and Social Change - Research Paper Example This paper will examine the reggae music genre, discussing its impact on society. Bob Marley, as well as other notable reggae artists, has a definite influence on the society as they advocate for social change through their music. During his brief life (1945-1981), Bob Marley rose from obscurity and poverty to international superstardom. Bob Marley remains the single third world artist to attain such worldwide acclaim. Bob Marley attained this status through charisma and ambition, and was it, not for these traits, reggae music would still be restricted to Jamaican ghettoes, which was its origin. Bob’s life changed when Haile Selassie visited Jamaica. Haile Selassie, the Ethiopian Emperor, was a cherished savior of Africans in Jamaica. Bob’s ideologies shifted after spending one year in America where he witnessed the evils of the free market, as well as the oppression of capitalism while working at a major corporation (Stephens 34). After returning to Jamaica, Bob established the Rastafarianism religion, which entailed wearing his hair in dreadlocks. Rastafarianism had a significant influence on Bob’s music as he sang about how the white race oppressed Africans. Bob’s main songs that speak to social change are Buffalo Soldier and Could You be Loved. Bob’s reputation transcended the controversy associated with his practice of Rastafarianism. He was regarded as a peacemaker, which is notable through his Smile Jamaica concert that sought to reduce tensions between rival gangs associated with two of the main national parties during an election period (White 124). Bob and his best friend Bunny wrote many songs that had a monumental impact on the Jamaican and global society. Bob used his music to send off messages of hope, love, and peace (Jah). At the end of all his songs, Bob Marley used the words â€Å"Jah Rastafari† to show his belief in Jah, i.e. peace and love.  

Design Of A Sulfuric Acid Production Plant Engineering Essay

Design Of A Sulfuric Acid Production Plant Engineering Essay This project is prepared according to the requirements of chemical engineering department, and its also a preliminary study of sulfuric acid production plant. The project begins with chapter one which includes introduction, definition of sulfuric acid and shows the main uses of sulfuric acid which have made it an important chemical in the world, followed by chapter two which talks about literature, market survey and the history and current processes for production the sulfuric acid also it gives small glimpse of the prices trends of the raw material and product. That is followed by description for various processes to produce sulfuric acid in chapter three, which ends with the selection of the best process which is the double contact process; the description and flow sheet of the selected process are discussed in chapter four. Material and energy balance results are listed in chapter five and the location of the plant is selected in chapter six by comparing different 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 used charts and references. CHAPTER ONE INTRODUCTION 1.1 Definition Sulfuric acid is a strong mineral acid with the molecular formula H2SO4. It is a clear, colorless, odorless, viscous liquid that is very corrosive. It is soluble in water at all concentrations. Sulfuric acid has many applications, and is one of the top products of the chemical industry. There are another names for sulfuric acid, it is sometimes called oil of vitriol.1 Its chemical formula is Figure (1.1.1): Sulfuric Acid Formula1 1.2 Physical and Chemical properties This table shows the main chemical and physical properties of sulfuric acid Sulfuric acid IUPAC Oil of vitriol Other name H2O4S Molecular formula 98.08 g molà ¢Ã‹â€ Ã¢â‚¬â„¢1 Molar mass Clear, colorless, odorless liquid Appearances 1.84 g/cm3, liquid Density 10  Ã‚ °C, 283  K, 50  Ã‚ °F Melting point 337  Ã‚ °C, 610  K, 639  Ã‚ °F Boiling point Miscible Solubility in water à ¢Ã‹â€ Ã¢â‚¬â„¢3 Acidity(pka) pungent odor Odor Non-flammable Flash point 26.7 cP (20  °C) Viscosity 0.3 Ph Table (1.2.1): physical properties1 1.3 Application and Uses Sulfuric acid is a very important chemical commodity, and indeed, a nations sulfuric acid production is a good indicator of its industrial strength. It is used as electrolyte in lead-acid batteries (accumulators) . It is important in the production of fertilizers such as ammonium sulfate (sulfate of ammonia), (NH4)2SO4, and superphosphate, Ca(H2PO4)2, which is formed when rock phosphate is treated with sulfuric acid. It is used to remove oxides from iron and steel before galvanising or electroplating . Concentrated sulfuric acid is used as a dehydrating agent, that is, to remove water, since it has a tendency to form hydrates such as H2SO4.H2O, 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 refining to wash impurities out of gasoline 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 even glue.1 This chart shows the distribution of using sulfuric acid Figure (1.3.1): Sulfuric Acid Distribution.1 Specification of raw materials sulfur, S, 16 Name, symbol, number 32.065g ·molà ¢Ã‹â€ Ã¢â‚¬â„¢1 Standard atomic weight Yellow colored lumps, crystals, powder, or formed shape Appearances Lumps 75-115 lbs./ft3 Powder 33-80 lbs./ft3 Bulk Density 388.36  K,à ¢Ã¢â€š ¬Ã¢â‚¬Å¡115.21  Ã‚ °C,à ¢Ã¢â€š ¬Ã¢â‚¬Å¡239.38  Ã‚ °F Melting point 717.8  K,à ¢Ã¢â€š ¬Ã¢â‚¬Å¡444.6  Ã‚ °C,à ¢Ã¢â€š ¬Ã¢â‚¬Å¡832.3  Ã‚ °F Boiling point Insoluble Solubility In Water Solid Physical State 1.819 g ·cmà ¢Ã‹â€ Ã¢â‚¬â„¢3 Liquid density at maps. Table (1.3.1): Physical Chemical Properties of Sulfur.1 CHAPTER TWO LITERATURE AND MARKET SURVEY 2.1 History and Current processes The discovery of sulfuric acid is credited to the 8th century chemist 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 dry distillation of minerals including iron(II) sulfate heptahydrate, FeSO4 ·7H2O, and copper(II) sulfate pentahydrate, CuSO4 ·5H2O. When heated, these compounds decompose to iron(II) oxide and copper(II) oxide, respectively, giving off water and sulfur trioxide, which combine to produce a dilute solution of sulfuric acid. 1 This method was popularized in Europe through translations of Arabic and Persian treatises, as well as books by European alchemists, such as the 13th-century German Albertus Magnus.1 There are two major processes (lead chamber and contact) for production of sulfuric acid 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 contact process produces a purer, more concentrated acid but requires purer raw materials and the use of expensive catalysts. n both processes sulfur dioxide is oxidized and dissolved in water. The sulfur dioxide is obtained by burning sulfur, by burning pyrites (iron sulfides), by roasting nonferrous sulfide ores preparatory to smelting, or by burning hydrogen sulfide gas. Some sulfuric acid is also made from ferrous sulfate waste solutions from pickling iron and steel and from waste acid sludge from oil refineries. 1 2.2 Supply and Demand This table shows the production rates of sulfuric acid (in metric tones) in some countries at different years. Production of sulfuric acid in metric tones Year country 1994 1997 2000 2006 France 2227 2242 2269 1755 Germany 3380 3496 4898 4595 Greece 360 675 688 815 Italy 1228 1590 1043 1616 Spain 2348 2810 2418 3500 United kingdom 1225 1205 1058 447 Sweden 518 630 629 1010 Table (2.2.1): Production Rates of Sulfuric Acid.3 This 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) Ù Sulfuric acid Year Sales (ton/year) Production (ton/year) 370925 43824 1108605 2000 309816 46614 919548 2001 351011 43307 1055208 2002 265865 51445 961208 2003 364301 49661 1102899 2004 346345 48323 1046540 2005 Table (2.2.2)Jordan Production, Sales and Raw Material Consumption.5 2.3 Prices trends of the raw material and product The global sulfuric acid market experienced an unprecedented rise and fall in pricing between fall 2007 and spring 2009. Consumption of sulfuric acid for fertilizers fell steeply in the second half of 2008 due to the collapse in the global economy. The second half of 2009 is expected to experience almost 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 continuing to deteriorate as the supply shortage situation has been replaced by product oversupply in almost all regions. And the world sulfuric acid supply trends are shown in the following chart. Figure (2.3.1): World Sulfuric Acid Supply.2 CHAPTER THREE PROCESS SELECTION Process Selection Sulfuric acid is an important raw material used in many industrial processes, such as phosphate fertilizer production and to a much lesser extent for nitrogen and potassium fertilizers, sulfuric acid is produced by catalytic oxidation of sulfur dioxide to sulfur trioxide, which is subsequently absorbed in water to form sulfuric acid. There are no major variations of commercial interests on this mentioned chemistry. There are alternatives as to source of Sulfur dioxide and method of conversion to sulfur trioxide. The two most common methods for the conversion of sulfur dioxide to sulfuric acid are: 1. Lead Chamber Process. 2. Contact Process 3.1 Lead Chamber Process This 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 stages: Glover tower, lead chambers and Guy-Lussac Tower. In this method hot sulfuric dioxide gas enters the bottom of the reactor called a Glover tower where it is washed with nitrous vitriol (sulfuric acid with nitric oxide, NO, and nitrogen 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 68% H2SO4) is achieved by the hot gases entering the tower which evaporate 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 series 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 through the chambers they are passed into a reactor called the Gay-Lussac tower where they are washed with cooled 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 discharged into the atmosphere. Product acid at a concentration of 78% H2SO4  is drawn from the cooled acid stream that is circulated from the Glover tower to the Guy-Lussac tower.   Nitrogen losses are made up with nitric acid which is added to the Glover tower. The major disadvantage includes the limitations in throughput, quality 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 Process Because of economic reasons Contact plants are widely used compared to the lead plants, they are classified 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 (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 kept agitated to improve heat transfer, to prevent solids settling on the bottom of the sulfur pits 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 130 °C is sprayed into the burner in the presence of warm, dry air. The sulfur burns, forming sulfur dioxide S + O2 â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚   SO2 à ¢Ã‹â€ Ã¢â‚¬  H = -300 kJ mol-1 The resulting sulfur dioxide is fed to a process unit called a converter, where it is catalytically oxidized to sulfur trioxide (SO3): 2SO2 + O2 â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  2SO3 ΆH = -100 kJ mol-1 Its apparent that the equation gives a decrease in volume; this reaction would be aided by pressure. High 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 formation of SO3: As this is an exothermic process, a decrease in temperature by removal of the heat will favour the formation of SO3. Increased oxygen concentration. SO3 removal (as in the case of the double absorption process). Increased pressure. Catalyst selection, to reduce 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 catalyst, the characteristics of the used catalyst are: Porous carrier having large surface area, controlled pore size and resistance to process gases at high temperature; in pellet form if used in fixed bed and powdered form if used for fluidized bed. Ex- Alumina, silica gel, zeolites. Active catalytic agent: Preparations are generally kept secret for the competitive reasons but they usually consist of adding water soluble compounds to gels or porous substrates and firing at temperature below the sintering point. Promoter: Alkali and/or metallic compounds added in trace amounts to enhance the activity of the catalytic agent. A catalyst, vanadium pentoxide (V2O5) is used to increase the reaction rate because its relatively immune to poisons, also because of its low initial investment and only 5% replacement per year. It is only effective above its melting point of 400  °C. The greatest conversion of SO2 to SO3 is reached by passing the gas over several catalyst beds, cooling the gas between each pass so that the reaction temperature remains between 400 and 500  °C. As can 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 larger 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 follows: SO3 + H2O â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  H2SO4 à ¢Ã‹â€ Ã¢â‚¬  H = -200 kJ mol-1 It 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 rather common place. The contact process can be applied in different techniques; three of those techniques are described in the following sections 3.2.1 Single contact / single absorption process After 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 desired concentration of approximately 99% w/w by addition of water or dilute H2SO4. The single contact/single absorption process is generally 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 Absorption Process The double contact process was implemented to develop the single contact/single absorption process. In this process a primary SO2 conversion of 85 95 % is achieved 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 possible 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 the double contact process at an elevated 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 NOx 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 catalysis plant. 3.2.3 Wet catalysis process The wet 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 installed after the contact tower. Factors Sulfuric Acid Production By Lead Chamber process Sulfuric Acid Production By single contact/single absorption process Sulfuric Acid Production By double contact/double absorption process Sulfuric Acid Production By Wet Catalysis process Health and safety hazards involved Less safe, waste gases are discharged to the atmosphere Less amount of SO3 is absorbed so the rest is discharged to the atmosphere A larger amount of SO3 is absorbed A larger amount of SO3 is absorbed Operating cost High operating cost Less operating The least operating cost Less operating cost Raw material SO2, 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 Exhaust gases are discharged to the atmosphere Large amounts of SO2 gas are discharged to the atmosphere Less amounts of SO2 gas are discharged to the atmosphere, less heat released after each successive catalyst bed. A larger amount of SO3 is absorbed Equipment Acid 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. Yield Yields 78% H2SO4 New plants achieve 98 to99 % conversion rates Yields about 98% Yields 70 to 80 % H2SO4   Environmental pollution More gases are discharged to the atmosphere More gases discharged to the atmosphere Less gases discharged to the atmosphere More gases are discharger to the atmosphere Purity of products Low purity Low purity High purity Low purity Table (3.2.1): Process selection Factors Sulfuric Acid Production By Lead Chamber process Sulfuric Acid Production By single contact/single absorption process Sulfuric Acid Production By double contact/double absorption process Sulfuric Acid Production By Wet Catalysis process Health and safety hazards involved 5 5 5 3 Operating cost 6 4 7 5 Raw material 6 5 7 5 Waste products and by products 6 6 7 5 Equipment 7 5 8 6 Yield 5 6 7 9 Environmental pollution 5 5 6 4 Purity of products 6 5 7 9 Total (80) 46 41 54 46 Table (3.2.2): Process Selection According to the discussion and the data presented above we choose the Double Contact/Double Absorption process. CHAPTER FOUR PROCESS DISCRIPTION 4.1 Production of H2SO4 by double contact process The 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 maintained at (8 9%v/v) sulfur dioxide and approximately 830 °C 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 roughly in accordance with the figure (4.1.1) as shown. Figure (4.1.1): Theoretical Flame Temperature.8 This 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 heated, 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 equation: 2SO2 + O2 â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  2SO3 ΆH = -100 kJ mol-1 This 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 percentage 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 equilibrium point will not be reached. In practice, the gas temperature must be maintained between (400 500 °C) 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.7 The 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 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 acid: SO3 + H2O â‚ ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  Ã¢â€š ¬Ã‚  H2SO4 à ¢Ã‹â€ Ã¢â‚¬  H = -200 kJ mol-1 The circulating sulfuric acid must be maintained at about 98% concentration and temperature is controlled in the desired rang of (70 °C_90 °C) to maximize the absorption efficiency. The acid strength is important because the vapor 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 Between Vapor Pressure and Concentration.7 Figure (4.1.4) : Flow Sheet CHAPTER FIVE ENERGY AND MASS BALANCE 5.1 MASS BALANCE *Drier: Components Amount % H20 1.27 1.3 O2 21.12 23 N2 69.4 75.7 Temperature 25C pressure 1 atm M1 M2 Components Amount % H2SO4 39.4 98 H2O 0.8 2 Temperature 150C pressure 1 atm M3 Components Amount % O2 21.12 23.3 N2 69.4 76.7 Temperature 25C pressure 1 atm M4 Components Amount % H2SO4 39.42 95 H2O 2.1 5 Temperature 150C pressure 1 atm *Burner: M3 Components Amount % O2 21.12 23.3 N2 69.4 76.7 Temperature 26C pressure 1 atm M5 Components Amount % S 3.76 100 Components Amount % SO2 28.16 29 O2 7.04 7 N2 69.4 64 Temperature 830C pressure 1 atm   M6 *Converter: M6 Components Amount % SO2 28.16 29 O2 7.04 7 N2 69.4 64 Temperature 400C pressure 1 atm M7 Components Amount % O2 2.11 2 N2 69.44 66 SO2 8.45 8 SO3 24.64 24 Temperature 450 pressure 1 atm M8 Components Amount % SO2 26.72 26 O2 1.69 1.6 N2 69.44 66.4 SO3 26.72 26 Temperature 450 pressure 1 atm M9 Components Amount % SO2 0.314 6 O2 0.0768 1.5 N2 3.47 66.5 SO3 1.36 26 Temperature 450 pressure 1 atm M10 Components Amount % SO2 0.314 6 O2 0.0768 1.5 N2 3.47 66.5 SO3 1.36 26 Temperature 450 pressure 1 atm M11 Components Amount % SO2 6.08 6 O2 1.54 6 N2 65.97 66.5 SO3 25.84 26 Temperature

Palestine By Joe Sacco; A Book Review Essay -- essays research papers

Joe Sacco’s graphic novel, Palestine, deals with the repercussions of the first intifada in Israel/Palestine/the Holy Land. The story follows the author through the many refugee camps and towns around Palestine as he tries to gather information, stories, and pictures to construct his graphic novel. While the book is enjoyable at a face level, there are many underlying themes conveyed throughout its illustrated pages and written text. The most obvious of the themes is that of violence, brutality, and torture. Tied into this also is the idea of injustice. Many of these themes are intertwined. Constantly the reader is berated with violent images, or descriptions of violence. These must be on nearly every second page of the novel. A good example of all these themes together is in the section called â€Å"Moderate Pressure: Part Two† This deals with a story of a man called Ghassan who was accused of an affiliation with an illegal group that could not be proven. Ghassan was forced to stand or sit in certain positions for hours on end, he was beaten, deprived of sleep, and restricted from medical attention that he needed. Continually he went to court, and the case was adjourned to later dates to try to confiscate some kind of evidence against him. There was no justice for Ghassan until after several days (approximately 14); he was released for lack of evidence. Ghassan suffers from violence (which is unjust), fro m brutality (one of the inspectors trying to induce a heart attack), and torture. Ghassan’s ordeal is illustrated in both written and pictorial form. Likewise to this, there are many other pictorial examples and textual examples from front to back of violence, brutality, injustice, and torture . There is also the theme of hypocrisy littered throughout the pages of Joe Sacco’s novel. This idea of hypocrisy is mainly centred on what the Israelis do to the Palestinians. In images the hypocrisy is apparent. Often there are pictures of the Palestinians on the same page, or on the second page but aligned with the Israelis. Often the Israeli side is shown as more optimistic, brighter, or livelier than those portraying the Palestinians. An excellent example of this is on page 260, where both Tel Aviv and Nablus are portrayed. In Tel Aviv, Sacco is reclined on a chair, with two attractive women, and it appears to be a sunny warm day, in Nablus, Sacco is with a crowd of... ...seem unnecessary and oppressive, but to certain Palestinians it is a matter of religious faith. Another example that shows this is when Sacco is in a car with Khaled . Kahled asks Sacco about things in the West that strike him as ‘bad’, but are quite normal to people from the West (i.e. Sex). These characteristics of evil also impact on an individual’s personal opinion of what is evil. In Palestine, the reader is exposed to various characters’ personal opinion of what evil or good is. An example of this is the figure of Suddam Hussein, to many people (Westerners, Israelis); Hussein is a very ‘evil’ figure. However, to some of the Palestinians represented, Hussein was a force of good, of liberation, the ‘final hope’. Evil in the novel is portrayed to the reader in many contexts that our society and cultural norms and values can understand. Brutal violence, deprivation, apartheid, and torture are all symbols of what we would see as evil. The book portrays the evil as seen by the Palestinians, many of these characteristics matching our own societal ideas of evil, so that the reader can comprehend. Bibliography Sacco, Joe. Palestine. Fantagraphics Books, Seattle: 2001.