Health Care Provision and Poverty Essay Example | Topics and Well Written Essays - 1000 words

Health Care Provision and Poverty - Essay Example This is not the case as the entire blame lies on the government which has for the longest time possible ignored the plights of the poor in relation to health care provision. Matters of insurance and health care heavily impacts on the poor as they are the minority in the nation and, therefore, cannot have access to such services. It is common knowledge that lack of access to proper medical aid at the appropriate time can only lead to more suffering of the patient. According to analysts, healthcare has become unaffordable for businesses and individuals because of varied reasons. The most prominent reasons for lack of health care services are poverty, lack of employment, and employers transfer of healthcare costs to their employees. The burden of health care is not any better for the employed Americans. These employed people have to pay more out of their pockets for medical services and doctor visits. Employed people contribute towards health care in the form of taxes which is deducted from their salaries on a monthly basis. The major reason for lack of health care for the employed is that health care has become too expensive, and families opt to keep the matters of health care on hold. Culturally, the cost of health care services should be on the employing unit and not the worker. An employer should never put more on an employee through health care as these can lead to high employee turnover. In as much as employers may not have adequate funds to support the health care programs, it is their duty to ensure that employees have access to proper medical services. Most Americans give priority to the provision of other basic needs like food, clothing, and home. Healthcare comes in as a secondary need and people will struggle to provide for it in times of need. There is a high death rate for Americans as they fail to have access to medical aid at the appropriate time or when they fall sick, they have no sufficient funds to cater for the medical need. Records of America ns way of spending indicate that their priority bills are mortgage, rent, car payments, and other adulthood obligations. People do not give health care priority because it is expensive to maintain an insurance cover especially for the entire family. With this in mind, it is only fair that the government takes up some responsibilities like provision of free health care to its citizens. Analysts believe that this will be instrumental in maintaining America’s image as one of the wealthiest and industrialized nation (Doug, 2010, pg 12). Health care services become an even extreme case for the unemployed. Insurance is a luxury for Americans with no jobs or who have just lost their jobs recently. Reports on channel 7 news showed the relationship between unemployment and free health care clinics. The rise of unemployment level in America has seen the growth of free health care clinics. The only obstacle in this case is the crowding in these health care clinics as most people are une mployed (Andrews, 2011, pg 40). In addition, the free health care clinics will only serve people who have current insurance cover. This idea cuts out so many people from using their services as most people in America have no cover because of its cost. Another option for the unemployed Americans is cobra subsidy policy, which caters for 65% of the whole bill. This is subject to people accepting to pay more after fifteen

Psychology Revision Notes Essay Example for Free

Psychology Revision Notes Essay Participants were divided into four groups which were acoustically similar, acoustically dissimilar, semantically similar and semantically dissimilar. Participants were presented with the list a total of 4 times and each time was interrupted to try to prevent rehearsing. They were then presented with a 20-minute interval task and afterwards were asked to recall their list. Semantically dissimilar words were recalled the most telling us that encoding in LTM is semantic. Summary of study on capacity of STM and LTM  Summary of study on duration of STM  Peterson Peterson-  Showed PPs a list of nonsense trigrams and asked them to count back from 400 in 3 second intervals for a duration ranging from 3 to 18 seconds. Found that duration of STM was 18-30 seconds maximum.  Summary of study on duration of LTM  Bahrick-  400 participants aged between 17 and 74 were tested using different methods including free-recall tests, photo-recognition test, name recognition tests and photo-name matching test. PPs performed less well on free recall tests (30% after 48 years) but were much better in the photo-name test (90% after 60 years). Models of memory  Description of the multi-store model of memory, plus evaluation inc. research  Atkinson Shiffrin-  Multi-Store Model which consists of three parts sensory, short term and long term stores. Rehearsal is required in order for information to move across stores and retrieval is needed to access the information. If information is not rehearsed it will decay.  Description of the working memory model, plus evaluation inc. research Baddeley Hitch-  Working Memory Model which consists of three parts central executive, phonological loop (store and articulatory control system) and the central executive. Memory in the real world  Knowledge of what Eye Witness Testimony (EWT) is-  The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime. The accuracy of eyewitness recall may be affected during initial encoding, subsequent storage and eventual retrieval.  Loftus Palmers (1974) study on EWT-  Reconstruction of an Automobile Disaster. 9 student PPs per 5 conditions (bumped, contacted, hit, smashed and collided). All watched a video then asked to estimate speed. Smashed the highest (40.8mph) and contacted the lowest (31.8mph). PPs in second part of experiment then asked a leading question about broken glass. 16/50 of the smashed condition PPs said yes in comparison to 7/50 in the hit condition. Knowledge of the factors which affect the accuracy of EWT  anxiety-  Christianson and Hubinette (1993)  Anxiety and EWT real incidents involving high levels of stress lead to more accurate, detailed and long lasting memories.  Deffenbucher (2004)  Carried out a meta-analysis of 18 studies, looking at the effects if heightened anxiety on accuracy of EWR. It was clear that there was considerable support for the hypothesis that high levels of stress negatively impacted on the accuracy of EWM. Age-  Parker and Carranza (1989)  Compared the ability of primary school children and college students to correctly identify a target individual following a slide sequence of a mock crime. In the photo identification task, child witnesses has higher rate of choosing somebody than adults witnesses, although they were also more likely to make errors of identification than college students.  Weapon focus effect-  Loftus(1987)  In violent crimes, arousal may focus attention on central details e.g. a weapon. Loftus et al identified weapons focus effect. 2 conditions, one involving weapon the other not. Condition 1 (less violent) people was 49% accurate in identifying man. Condition 2 (more violent) people were 33% accurate. Suggests weapon may have distracted them.

A Study On Cumene Plant Engineering Essay

A Study On Cumene Plant Engineering Essay The system considered for study, simulation and optimization is a cumene production plant. The process described by Peterson and Schmidt is taken as base for simulating the system. The process description of Turton et al. (2003) provides relevant and valuable data required for the simulation of the process. Raw materials fed to the plant are benzene and propylene (may contain propane as an impurity) in which benzene is in excess. Various unit operations and processes are required to be taken care of which are described in some detail below. The major units in the process plant are the reactor section and the separator section. 1.2 RELEVANCE Isopropyl benzene popularly known as cumene is the principal chemical used in the production of phenol and its co-product acetone on an industrial scale. It is also the starting material in the production of acetophenone, methyl styrene, diisopropyl benzene and dicumyl peroxide. Minor uses of cumene include as a thinner for paints, enamels, and lacquers; as a constituent of some petroleum-based solvents, such as naphtha; in gasoline blending diesel fuel, and high-octane aviation fuel. It is also a good solvent for fats and resins and has been suggested as a replacement for benzene in many of its industrial applications. Around 98% of cumene is used to produce phenol and its co-product acetone. However, the requirement of cumene is largely dependent on the use of phenol’s derivatives which have resulted in increasing requirement rates for cumene. The largest phenol derivative is bisphenol-A (BPA) which supplies the polycarbonate (PC) sector. PC resins are consumed in automotive applications in place of traditional materials such as glass and metals. Glazing and sheet uses, such as architectural, security and glazing outlets, are also important PC applications. The third largest use for PC is optical media such as compact discs (CDs) and digital versatile discs (DVDs). Another phenol derivative is caprolactam which is used mainly to make nylon 6. It is mainly the resin sector of the nylon market that is seeing growth. [Schmidt, 2005] Cumene is produced by the alkylation of benzene with propylene over an acid catalyst like aluminium chloride, boron trifluoride, phosphoric acid, hydrogen fluoride, supported phosphoric acid (SPA) etc. The usage of the above catalysts poses a lot of problems like product quality, lower catalyst activity, environmental hazard, catalyst non-regenerability etc and has been replaced by zeolites in most of the processes. In the present work the cumene production plant is simulated using ASPEN PLUS  ® and the sizes, the temperature and other relevant parameters are obtained by optimization. MATLAB ®, MS Excel and Origin Pro 8.0 are used to plot graphs in the following simulation from which an optimum value is estimated. The optimized values obtained can provide a lot of insight before actual plant commissioning is done. 1.3 OBJECTIVE OF THE PROJECT Considering the importance of the present process, work was undertaken to design and simulate the cumene production process using ASPEN PLUS  ® software. The objectives of the present project are following. To design a zeolite catalyst based cumene production process and study the sensitivity analysis. To optimize the contents of the flow sheet for minimization of loss of material along with a greater production of cumene and low requirement of energy. CHAPTER 2 LITERATURE REVIEW 2. LITERATURE REVIEW 2.1 CONVENTIONAL PROCESS Cumene is produced by the alkylation of benzene with propylene over an acid catalyst. Catalysts like aluminium chloride, boron trifluoride, hydrogen fluoride and solid phosphoric acid (SPA) are normally used. Over the years these catalysts have given way to zeolite based catalysts. There are some inherent problems associated with the conventional acid catalysts. Disadvantages of using solid phosphoric acid (SPA) Process Lower activity Catalyst non-regenerability Unloading of spent catalyst from reactor difficult Relative high selectivity to hexyl benzene Significant yield of DIPB Disadvantages of using Aluminium chloride as catalyst High corrosion Environmental hazard Washing step for catalyst removal. 2.2 CURRENT INDUSTRIAL PROCESS Cumene is an important chemical in the present industrial world and its uses are steadily increasing. The process followed for the production of cumene is the catalytic alkylation of benzene with propylene and now a days zeolite based catalysts are used in place of the normal acid based catalysts due to added advantages. Cumene production process has been greatly studied and the reaction mechanism and the reaction kinetics have been specified by many researchers. Both experimental as well as computer based simulation and optimization studies have been carried out by various researchers. The significant works of various researchers which have been helpful in my project are described in brief below. The Q-Max â„ ¢ process converts a mixture of benzene and propylene to high quality cumene using a regenerable zeolite catalyst. The Q-Max â„ ¢ process is characterized by a exceptionally high yield, better product quality, less solid waste, decrease in investment and operating costs and a corrosion free environment. The Q-Max â„ ¢ process developed by UOP uses QZ-2000/ QZ-2001 catalyst which is a variant of ß zeolite. [Schmidt, 2005] 2.2.1 PROCESS DESCRIPTION The Q-MAXâ„ ¢ process provides a very good cumene yield and quality. The QZ-2000 zeolite based catalyst used in the Q-MAXâ„ ¢ process operates with a low flow rate of benzene and hence investment and utility costs are reduced greatly. QZ-2000 is non-corrosive and regenerable, avoiding the significant maintenance and catalyst disposal problems associated with SPA and AlCl3 systems. Compared to other zeolite based cumene technologies, the Q-MAXâ„ ¢ process provides better tolerance of feedstock impurities, the highest cumene product quality and excellent stability. The Q-MAXâ„ ¢ process flow scheme is shown in fig 2.1 above. The alkylation reactor is divided into four catalytic beds present in a single reactor shell. The fresh benzene feed is passed through the upper-mid section of the depropanizer column to remove excess water and then sent to the alkylation reactor. The recycle benzene to the alkylation and transalkylation reactors is a drawn from the benzene column. This mixture of fresh and recycle benzene is charged through the alkylation reactor. The fresh propylene feed is split between the catalyst beds and is fully consumed in each bed. An excess of benzene helps in avoiding poly alkylation and minimizing olefin oligomerization. Because the reaction is exothermic in nature, the temperature rise in the alkylation reactor is controlled by recycling a portion of the reactor effluent to the reactor inlet to act as a heat sink. The inlet temperature of each downstream bed is further reduced to the same temperature as the first bed inlet by injecting a portion of cooled reactor effluent between the beds. Effluent from the alkylation reactor flows to the depropanizer column which removes the propane that entered with the propylene feed along with excess water. The bottoms stream of the depropanizer column goes to the benzene column where excess benzene is collected overhead and recycled. The benzene column bottoms stream goes to the cumene column where the cumene product is recovered overhead. The cumene column bottoms stream, predominantly diisopropylbenzene (DIPB), goes to the DIPB column. If the propylene feed contains excessive butylenes, or if the benzene feed contains excessive toluene, butylbenzenes and/or cumene are distilled out and purged from the overhead section of the DIPB column. The DIPB stream leaves the column by way of the side draw and is recycled back to the transalkylation reactor. The DIPB column bottoms consist of heavy aromatic by-products, which are normally blended into fuel oil. Steam or ho t oil provides the heat for the product fractionation section. The recycle DIPB from the overhead of the DIPB column combines with a portion of the recycle benzene and is charged downflow through the transalkylation reactor. In the transalkylation reactor, DIPB and benzene are converted to more cumene. The effluent from the transalkylation reactor is then sent to the benzene column. The new QZ-2001 catalyst is utilized in the alkylation reactor while the original QZ-2000 catalyst remains in the transalkylation reactor. Expected catalyst cycle length is 2–4 years, and the catalyst should last for at least three cycles with proper care. At the end of each cycle, the catalyst is typically regenerated ex situ via a simple carbon burn by a certified regeneration contractor. However, the unit can also be designed for in situ regeneration. The Q-Maxâ„ ¢ process typically produces near equilibrium levels of cumene (between 85 and 95 mol %) and DIPB (between 5 and 15 mol %). The DI PB is separated from the cumene and is reacted with recycle benzene at optimal conditions for transalkylation to produce additional cumene. [Schmidt, 2005], [Peterson and Schmidt, 2002] 2.2.2 REACTION MECHANISM AND KINETICS The following reaction mechanisms are proposed for the alkylation of benzene to cumene process. The major reactions taking place are alkylation and trans-alkylation. The other reactions involved include isomerisation and dis-proportionation. The reaction mechanism as well as the reaction kinetics may vary depending on the catalyst used. The reaction can proceed by with or without carbonium ion intermediate. [Ding and Fu, 2005] The rates of reaction data was obtained for different catalysts from the work done by various researchers. The kinetic data and the reaction conditions specified by Turton et al (2003) for a particular catalyst have been used in the present work. The reaction kinetic data is shown below Propylene + benzene à   cumene K = 2.8 Ãâ€" 107 E (kJ/kmol) 104174 Rate=kcpcb Propylene + cumene à   p-diisoproyl benzene K = 2.32 Ãâ€" 109 E (kJ/kmol) 146742 Rate=kcpcc (The unit for rates is kmol s-1 m-3) [Turton et al, 2003] Trans-alkylation reaction K= 6.52 Ãâ€" 10-3 exp (27240/RT) The equilibrium data for trans-alkylation reaction is obtained for modified zeolite beta catalyst, YSBH-01. [Lei et al, 2007] From various works on cumene production mechanism the overall reaction can be assumed to consist of the following stages. Alkylation Isomerisation Transalkylation Dis-proportionation 2.3 PROPERTIES OF CUMENE Description: Colorless liquid with a sharp, penetrating aromatic or gas-like odour [Budavari, 1989; Cavender, 1994] Boiling Point: 152.4 °C [Lide, 1995] Melting Point: -96.0 °C [Lide, 1995] Density: 0.8618 g/cm3 at 20 °C [Lide, 1995] Refractive Index: 1.4915 at 20 °C [Schulz et al., 1993]; 1.489 at 25 °C [Lewis, 1993] Solubility: Insoluble in water; miscible in acetone, benzene, and ethanol [Lide, 1995] Flash Point: 39 °C, closed cup [Budavari, 1989] Reactivity: Combustible [Lewis, 1993], not compatible with oxidizers, nitric acid and sulphuric acid. 2.4 PROCESS DESIGN BASICS Process design is a very important aspect before any project implementation as a proper design during the initial stages can save costs to a great extent. The cost involved in designing a project is very less compared to the construction cost and it can be greatly helpful in maximizing profits of the plant as well as providing a safe environment. The plot shown in Fig. 2.2 gives a brief idea of how proper plant design can cut costs to a great extent. The following points need to be taken care for a proper process design. Raw material cost reduction. Selectivity of reaction is increased by proper use of catalysts. Increasing selectivity can reduce separation and recycle costs. Capital-cost reduction. Better flow sheeting can reduce capital costs effectively Energy use reduction. Pinch point analysis is used for energy saving. Increased process flexibility. Process plant should be able to handle a range of feed compositions. Increased process safety. Nonlinear analysis can be done to make the process safer. Increased attention to quality. Reduction of by products and the effective use of process control equipment can lead to process safety. Better environmental performance. Minimization of harmful wastes to the environment. The order in which designing should be done follows a systematic procedure as shown in Fig 2.4. A process simulation diagram is drawn from the process flow diagram. The chemical components are specified. The chemical component properties are generally available in a standard data base. The input streams are specified. Thermodynamic modelling is done. Series of simulations are run for convergence of a particular variable. Sensitivity analysis which consists of varying the sampled variables as a function of the manipulated variables is normally done. The major parts of a cumene production plant are reactor system, separation system and they are optimized. CHAPTER 3 DESIGN: PROCEDURE, RESULT DISCUSSION This chapter is divided into two main parts as (i) Reactor and (ii) Separator. The reactor design involves design of equilibrium based reactor as well as kinetic based reactor. The separator system involves the design of flash tank and distillation column. As the product purity is increased by increasing the working cost of the reactor, the separation cost decreases and vice versa. The sequence of computation followed is shown in Fig. 3.1. 3.1 REACTOR DESIGN Reactor is the heart of a chemical process plant. Design of a reactor requires data from thermodynamics, chemical kinetics, fluid mechanics, heat transfer, mass transfer and economics. A properly designed reactor can minimize the production of unwanted products and hence reduce the purification costs. The alkylation and trans-alkylation reactors are the main reactors in a cumene production plant and they need to be designed for optimum use of material and energy. In all the optimization work done Douglas Doctrine (the costs of raw materials and products are usually much larger than the costs of energy or capital in a typical chemical process. Therefore the process must be designed (investing capital and paying for energy) so as to not waste feed stocks or lose products (particularly in the form of undesirable products) is followed. [Luyben, 2010] Kinetic model can be considered if accurate kinetic data is available. But a plant involves industrial reactors that are very complex and hence a proper combination of stoichiometric and kinetic reactor needs to be used. Kinetic model can determine the production rate where as stoichiometric model can describe the formation of by products and impurities necessary for the design of separators. Equilbrium based reactors like RGIBBS in ASPEN PLUS ® can give a realistic idea about the maximum achievable performance. They work accurately for fast reactions. The RGIBBS reactor predicts the equilibrium concentration by Gibbs free energy minimization. [Dimian, 2003] Generally in reactor design an equilibrium model is prepared and then the kinetic model. The following reaction mechanism was proposed by various researchers for alkylation of benzene by cumene. 3.1.1 REACTIONS CONSIDERED FOR MODELING Alkylation propylene + benzene à   cumene (1) propylene + cumene à   p-diisoproyl benzene (2) Isomerisation p-diisopropyl benzene à   m-diisopropyl benzene (3) Trans-alkylation p-diisopropyl benzene + benzene à   2 cumene (4) m-diisopropyl benzene + benzene à   2 cumene (5) Disproportination 2 cumene à   p-diisopropyl benzene + benzene (6) 2 cumene à   m-diisopropyl benzene + benzene (7) 3.1.2 REACTOR DESIGN PROCEDURE IN ASPEN PLUS The feed is a mixture of benzene and propylene such that benzene is in excess. In general propylene is not available in the pure form and has some amount of propane as inert. The separation cost of propane is high and hence normally propane is not removed from the propylene feed into the reactor. A high conversion of propylene is desired and the unreacted propylene can be flashed off along with the inert propane. RGIBBS reactor works by Gibbs free energy minimization. Alkylation and trans-alkylation reactors need not be modelled separately as they can be combined into one equilibrium reactor. The reactant, products as well as the intermediates as seen from the reaction mechanisms are specified into the component list. SYSOP0 or Ideal property table is used. A temperature range of 300 to 400 degree Celsius is specified and a proper temperature chosen. Pressure of 25 atm is chosen from previous industrial research work. [Luyben, 2010] 3.1.3 EQUILIBRIUM STUDIES The equilibrium is affected by the temperature as well as the benzene/propylene mole ratio. The alkylation and transalkylation reaction is usually carried out at atmospheric pressure. Therefore, the effect of pressure on the equilibrium was not considered in the present study. Seven reactor models are available in ASPEN PLUS. The equilibrium based RGIBBS reactor is used to find the product composition at which the Gibbs free energy of the product is minimum. The restricted chemical equilibrium approach is used and the reactions mentioned above are specified. The temperature approach for an individual reaction is used. The feed stream mole flow is set as 1 kmol / hr and the feed stream consists of benzene, propylene and propane (inert mixed with the propylene stream). Amount of inert in feed is kept fixed. The reactor temperature is set to 3500C and the reactor pressure is set to 25 atm. (a) The selectivity of cumene and conversion of propylene (limiting reagent) is studied by varying the benzene/propylene mole ratio in the feed keeping the amount of inert fixed. The effect of temperature variation (300–4000C) on the selectivity and the conversion is also studied. (b) Again, the variation in the selectivity of m-DIPB and p-DIPB with temperature and b enzene/propylene mole ratio in the feed is studied. The conversion and selectivity were calculated using equations 8 to 11. %Selectivity of cumene = Fcumeneproduct /(Fpropylenefeed-Fpropyleneprod) ´100% (8) %Conversion of propylene = (Fpropylenefeed-Fpropyleneprod)/Fpropylenefeed  ´ 100 % (9) %Selectivity of m-DIPB = Fmdipbproduct/(Fpropylenefeed-Fpropyleneprod)  ´100% (10) %Selectivity of p-DIPB = Fpdipbproduct/(Fpropylenefeed-Fpropyleneprod)  ´ 100% (11) Where Fcumeneproduct = molar flow rate of cumene in product Fpropylenefeed = molar flow rate of propylene in feed Fpropyleneprod = molar flow rate of propylene in product Fmdipbproduct = molar flow rate of m-DIPB in product Fpdipbproduct = molar flow rate of p-DIPB in product RSTOIC reactor model was used to find the standard heat of reaction for different reactions 1 to 6 mentioned above. The standard heats of reaction have been tabulated in Table 3.1.1. The heat of reaction for isomerisation was found to be zero as expected. The all other reactions were found to be exothermic except trans-alkylation reactions as observed from the table. Table 3.1.1 Standard Heats of Reaction Reaction Number Standard Heat of Reaction (Kcal/Kg mol) 1 -23.670 2 -24.321 3 0 4 0.649 5 0.649 6 -0.325 7 -0.324 Effect of temperature and benzene/propylene mole ratio. The effect of temperature and benzene/propylene mole ratio on equilibrium conversion of propylene and selectivity of products, cumene, m-DIPB, and p-DIPB is shown in Fig. 3.1.1. The conversion of propylene was found to increase with increase in benzene/propylene mole ratio for a fixed temperature as observed from the Fig. 3.1.1(a). This is because of reduced proportion of propylene in feed. However, variation of conversion of propylene was found to be negligibly small above the benzene/propylene mole ratio in feed of 3. The conversion of propylene was found to decrease with increase in temperature for a fixed benzene/propylene mole ratio as observed from the Fig. 3.1.1(a). This is because of the fact that overall heat of reactions is exothermic as shown in Table 3.1.1. The selectivity of cumene was found to increase with increase in benzene/propylene mole ratio at a fixed temperature as the polyalkylation reactions are reduced because of excess amount of benzene present in the feed (Fig. 3.1.1(b)). Again, with increase in temperature, the selectivity of cumene increases for a fixed benzene/propylene mole ratio as transalkylation reactions (endothermic, Table 3.1.1) are dominant at high temperature. The distribution of m-DIPB and p-DIPB is shown in Fig. 3.1.1 (c). From the figure it was observed that selectivity of m-DIPB is significantly higher than p-DIPB. This is because of the fact that m-DIPB is thermally more stable compared to p-DIPB. Therefore, p-DIPB formed in alkylation reaction isomerises to more stable meta isomer. Effect of inert on equilibrium. The propylene stream used in alkylation process is usually obtained by pyrolysis of petroleum fractions that contains small amount of propane as impurity. Propane need not be removed from the propylene stream as it acts as an inert and does not take part in the reaction. Presence of inert has very slight effect on the conversion as well as selectivity as shown in Fig.3.1.2. The conversion of propylene decreases slightly with higher volume percent of inert in feed and increases slightly with the same. 3.1.4 KINETICS BASED REACTOR MODEL Kinetics based rate data was obtained from the work of various researches and is mentioned above. A RPLUG model is used in ASPEN PLUS to model the reactor. The design model specified in the book by Turton et al (2003) is used. The reactions occur in the vapour phase in the presence of a solid catalyst (assumed to have 0.5 void fraction and a 2000 kg/m3 solid density). The reactor is run at high pressure (25 bar) since the moles of reactants are more than the moles of product (Le Chatelier’s principle). A temperature of 360 degree C and a benzene/Propylene mole ratio of 6 is used. A flow rate of 330 kmol/hr is used for the simulation. The kinetic model generated few errors such as RPLUG exited because integration failed. index = (-1) probable cause is incorrect kinetics. check rate-constant parameters and molar volume calculations. 3.1.5 PRODUCT OUTPUT FROM REACTOR Assuming the RGIBBS model for the initial calculations for distillation columns can give a good idea about the distillation process in a cumene plant. RGIBBS model with an input feed rate of 100 kmol/hr and benzene: propylene feed ratio of 6:1 with an inert concentration of 5% in propylene stream, temp. of 360 degree C and a pressure of 25 bar is used. The flow rates obtained at the product side are noted.The non condensable components in the product side i.e. propylene and propane are removed in flash tank. These components have fuel value only as they cannot be completely purified. So the reaction conditions should be so adjusted that the propylene in feed is totally converted to the product. The concentration of non-condensable components from reactor is given in Table 3.1.2. This data is used for further designing. Table 3.1.2 Mole flow rate of components from reactor Component Mole Flow kmol/hr Benzene 72.85 Cumene 10.31 m-DIPB 1.77 p-DIPB 0.47 TOTAL 85.4 3.2 PREDICTING VLE CHARACTERISTICS Reactors and separators can be considered as the back bone of any chemical process plant. The cost optimization of any plant depends largely on the reactors and the distillation columns. The basis of distillation is phase equilibrium that may be VLE (Vapour liquid equilibrium) and LLE (Liquid liquid equilibrium). Before designing any distillation equipment the VLE characteristics need to be studied as they give a fair amount of idea about the ease of distillation. The Txy diagram or temperature versus liquid composition (x) and vapour composition (y) are plotted. A fat curve generally shows that the liquids in a mixture can be easily separated. The boiling point data of the three major components in the distillation column is shown in Fig. 3.2.1 below. Table 3.2.1 Boiling point of components Component Boiling point in degree Celsius Benzene 80.2 Cumene 152.4 DIPB 209.8 The product stream from a condenser tank is sent to a distillation column. RADFRAC model is used. In the industrial process three distillation columns are used i.e benzene column, followed by cumene column and DIPB column.The RADFRAC model is a rigorous model for various multistage liquid vapour fractionation operations and hence is used for the simulation Before going in for the design of the distillation column the VLE diagrams need to be considered. The industrial processes currently followed show that in the 1st column benzene and cumene need to be primarily separated and in the 2nd column cumene and DIPB need to be separated. The NRTL (non random two liquid) physical property package is used used to plot the vapour liquid equilibrium T-XY for Benzene-cumene and Cumene-DIPB systems. The VLE plots are shown in Fig 3.2.1 to 3.2.3 for different systems. It can be inferred from plots Fig. 3.2.1 to 3.2.3 that separation would be easy and a distillation column with fewer trays and a smaller reflux ratio can be used. Azeotrope is not formed. Flash distillation should be tried as separation is easier. 3.3 FLASH DISTILLATION TANK DESIGN Distillation is tried using flash tank as the cost of operation is very low. FLASH2 model is selected. SYSOP0 property method is selected, which works by ideal or Roult’s law. Pressure of the flash tank is set as 1 bar. The input flow rate is same as mentioned in Table 3.1.2. The minimum boiling point in the mixture is that of benzene at 80.2 degree C at 1 atm and hence a temperature of 85 to 97.5 is considered for flashing. The mole fractions of benzene and cumene in the bottom and top products are found out at various flashing temperatures and plotted in Fig. 3.3.1. Assuming a product purity of 95% benzene in the top product the flashing temperature is identified to be 92.5 degree C. The flow rates from the flashing tank is shown in Table 3.3.1. Table 3.3.1 Concentration of products from the flash tank 92.5 degree C Benzene Cumene m-DIPB p-DIPB BOTTOM Product 18.951865 7.89384963 1.68473832 0.45287993 TOP product 5.39E+01 2.41615031 0.08526167 0.01712006 The flow rates of Table 3.3.1 act as a feed to the benzene column. 3.4 BENZENE DISTILLATION COLUMN DESIGN 3.4.1 DESIGN PROCEDURE RADFRAC-1 is selected for designing the Benzene distillation column. SYSOP0 property method is selected and the flow rates from Table 3.3.1 are used. The pressure is kept fixed at 1.75 bar and the temperature is kept fixed at 90 degree Celsius. These two variables are obtained from the experimental data specified by Turton et al (2003). These temperature and pressure data have been used in the work by Luyben (2010). The variables that can be optimized are reflux ratio, number of feed trays, feed tray location and distillate rate. In the initial assumption the distillate rate is kept at half the value of the feed rate. A total condenser is used in the process and an equilibrium based approach is used. 3.4.2 REFLUX RATIO OPTIMIZATION The number of trays (including boiler and condenser as a tray) is kept fixed at any value say 15. The feed tray is varied keeping the number of trays fixed. Now for each different ratio of number of trays to feed tray a series of reflux ratio starting from 0.1 is considered. The process is run and the mole fraction of benzene in the top product as well as the reboiler heat load data are used and a graph is plotted as shown in Fig 3.4.1. Reflux ratio is optimized by the variable mole fraction of benzene in the top product. An optimum reflux ratio value of about 0.5 is identified from Fig 3.4.1. At higher values of feed tray location (close to reboiler) lesser reflux ratio is required. Note that condenser is considered as the first stage and the rebolier as the last. 3.4.3 FEED TRAY LOCATION OPTIMIZATION The reflux ratio is kept fixed at 0.5 and the number of trays is kept fixed at 15. The position of the feed tray is varied and its affect on the reboiler heat load and the mole fraction of benze

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Being born and brought up in Afghanistan doesn’t go particularly smoothly, especially when compared to the contemporary standards of the UK. Aside from on-going war, many outbreaks of diseases have occurred, which I have first-hand experience of. At the age of 10 I contracted the water borne disease of cholera, due to our village’s water supply being heavily contaminated. I fully recovered, however the experience left me with a spark of inquisitiveness into the importance of maintaining a clean water supply and not allowing it be polluted. Today, chemical engineers are at the vanguard of maintaining clean water supplies to where they are abundant and establishing clean water supplies to where they are scarce, alongside their many other contributions to modern day scientific breakthroughs. Having studied Physics, Maths and Chemistry, I understand the obligation chemical engineers feel to contribute to the ever expanding global society. I had already thoroughly enjoyed these subjects at GCSE level and it only seemed right to me to pursue them at a higher level; when deciding my A-Level...

Understanding the Development Strategy of a Five Star Hotel

â€Å"Reflecting on My Group† Yuvakumar Naga Sindhura (n6994059) The purpose of this essay is to understand the development of strategy for a five star resort hotel. The process of development within the team and the understanding of the conflicting ideas. The strategy was meant to be developed for a fictitious resort hotel which consists of 150 rooms, with no specific location. A group consists of two or more individuals who work and interact with each other to achieve a common goal (Bartol, Tein, Mathews, & Martin, 2005). I worked with Ehsan, Armeen, in order to brainstorm and discuss possible strategies that could be possibly developed for the upcoming resort hotel. As a group we were unproductive as my members were unable to move without a location in mind and hence stagnated in formulating a strategy, which proved to be a major issue. Hence leading Inkpen (1996) (as cited in Bauerschmidt, 1996) to demonstate the presence in the absence of strategy. Mintzberg (1973) as cited in (Selveg, 1987) focuses mainly on the purpose of the decisions, who is involved in making them, how preferences are evaluated, and types of environments ideal for the mode. Therefore Mintzberg thus laid prominence on the process by which strategies surface, rather than on their content. But a personal strategy has been developed providing a direction for growth and success. My personal strategy formulated is an all-season resort destination of choice for visitors and residents, specializing in world-class alpine skiing and recreation facilities with a local historic and cultural focus, nestled amongst pristine forest terrain and rugged mountain ranges. This essay discusses and reflects upon our collective involvement and the processes and stages that we progressed. In this essay we shall explore Tuckmans(1965) stages of group development (forming, storming, norming, performing and adjourning), also defining the inputs, practices, processes and outcomes of working together in a group, along with the explanation and application of group cohesiveness, relevant member roles and leadership values which were supposed to be apparent within my group but lacked as everyone had opinions to what the leader had to say. As group members begin carrying out tasks and activities, eventually a team is evolved. Teams go through five stages of development as identified by Tuckman (1965), as cited in (Miller, 2003). Mostly all our meeting were held in class, our group had five undeceive individuals who only spent time discussing and brainstorming on what should be done first like the strategy, mission, vision or the values, rather than making a beginning. Therefore no progress was seen, even though worksheets were given during every class to guide us accordingly. Strategy was anticipated but was not fully present in the conflict of making one and it is believed that in this process the notion of strategies are in transition (Bauerschmidt, 1996). Therefore identifying group tasks and goals and building relations with each other was minimal. Tuckman(1965), as cited in (Miller, 2003) states that during this stage it is important that team members learn about each other, recognise the attitudes of other members and establish the goals and purpose of the group. During the regular interactions in the group meeting, we developed a positive relationship with each other, which is one of the key points suggested by (Tiosvold, Hui, Ding, & Hu, 2003) who supports the traditional idea that relationships are crucial for effective team performance. As a group we had different attitudes, values and cultural backgrounds, which could have thought to cause conflict within the team, but indecision was the highlight throughout, as some others in the group were skeptical of whether they were going the right direction, hence their opinions were not voiced and ideas were not shared both ways. It became a one way flow of ideas or discussion. But we experienced positive and friendly attitudes and exchange of ideas on varied topics, mostly apart from the topic of presentation and the assignment, thereby increasing our knowledge. As a group we experienced minimal cohesiveness. Cohesion in a group involves the level of purpose and commitment to the team among members (Dwyer, 2005). But due the difference in understanding and the mode of communication, the group ended up splitting into half, getting into sides where individuals understood each other. Cohesion is also linked to the input of knowledge and skills in a group, a group should have similar cultural backgrounds in order to be effective, to which I agree as all the members of our group came from different cultural backgrounds, with different values, efficiency and effectiveness, hence direction lacked in rder to achieve our goal. Groups with diverse attitudes and backgrounds are alternatively said to be more creative and flexible and make better decisions (Bartol et al. , 2005). I further refined the personal strategy formulated previously to develop a clearer direction for the growth and development of the organisation. The revised version of the strategy is an all-season resort destination of choic e for visitors and residents, specializing in world-class alpine skiing and recreation facilities with a local historic and cultural focus, nestled amongst pristine forest terrain and rugged mountain ranges. Offering personalised attention and facilities to physically unwind. It has been found in literature that the content and process of strategy emerge as two distinctly separate, but related concepts, and there appears to be no direct underlying relationship between strategy content and the process of strategy making but there is rather a relationship arising from and which is attributable to the holistic nature of an open social system (Van de Ven 1979 as cited by Seveg, 1987). Next stage of group development is storming; this is the stage when intra-group conflict and hostility can arise. All members of our group worked well together, but with a lot of challenging conflict. I believe we lacked the values of leadership skills, which did not give us the reinforcement to perform better. The ability to influence and develop individuals of a team, in order to achieve a worthwhile vision which meets the current needs of everyone and everything required by the form of work (Cacioppe, 2001 as cited in Volckmann 2005). Leadership skills portrayed at least by a member is required for a team to stay focused and move towards their goals. Leaders appear everywhere, depending on the circumstances that require them to exert leadership (Wheatley, 2005). This was least reflected by the chosen leader or the other members of the team. A self-managed team is an unsupervised group of people responsible for a task; they are given complete control over group membership and behaviors. Our self-managed team as in all other teams consisted of differing group-task roles, group roles fall into three categories; task, maintenance and self-orientated. Group-task related members help the group develop and accomplish its tasks and goals; and the group-maintenance, members within my group provided differences of opinions constantly but had a good level of interpersonal relationships with members, which to a level fostered group harmony but still resulted in ineffective group work (Bartol et al. , 2005). As my group progressed to the norming stage our relationships, goals and plans were still unclear, but we had to head off our ways to complete the assignment. Even though most of everything that we were supposed to do was unclear for us, we came to a consensus decision where the expression of cognitive conflict among members of the group is encouraged without allowing an explicit group interaction (Priem, Harrison and Muir, 1995). We then progressed to the performing stage of group development. This stage entails the development of interpersonal relationships, problem solving and achievement of performance, but was our performance a successful one? It is evident that there was lack of clarity throughout, but good level of interpersonal skills were maintained, however problem solving as a team lacked. At this stage I personally thought of revising my strategy for th resort management as it was long. The all-season resort destination specializing in world-class alpine skiing and recreation facilities with historic and cultural focus, nestled amongst pristine forest terrain and rugged mountain ranges away from the hustle bustle of daily life. Offering our customers personalised attention and facilities to physically unwind. After trying to put our heads to the requirements of our assignment we tried one last time to gather thoughts together thereby entering the adjourning stage, this involves goal accomplishment and the ultimate movement away from the group (Miller, 2003). We met together for the final time and reflected upon what we gathered and if what we gathered was sufficient and appropriate for our assignment. Overall, as a group we came to the mutual agreement that we as a team had no goal to achieve and our time was insignificantly wasted as we lacked an understanding of what we were to do and how we were to go about it. In conclusion the final strategy personally created was what remained for the organisation. As a group we departed our directions in order to formulate a strategy for the upcoming resort hotel. According Tuckman (1965) as cited by (Miller,2003) stages of team development we were unable to fit as we really did not understand our task at hand.

Free Essays on Procrastination

Procrastination is more than just a negative custom that needs to be weeded out of society; it is also a clichà ©Ã¢â‚¬Å¡ a small-talk joke, boast, or complaint. After all, we all do it. Most everybody I know is willing to admit it is an exasperating problem in their life, and would benefit from a course in How to Eliminate Procrastination, but say they have to much to catch-up on, and will take it later. There are many underlying issues and causes of procrastination. Lack of relevance and interest is two of the most common causes. While perfectionism having extremely high standards, which are almost unreachable is another problem all together. Evaluation, anxiety, ambiguity, fear of failure and self-doubt, fear of success, inability to handle the task, lack of information needed to complete the task, environmental conditions, physical conditions, moreover, and anxiety over expectations that others have of you, are all very serious causes of procrastination. Poor time management is a great cause of procrastination. Procrastination means not managing time wisely. One may be uncertain of one's priorities, goals, and objectives. Procrastinators may also be overwhelmed with the task. As a result, they keep putting off the assignments for a later date, or spending a great deal of time with your friends or worrying about upcoming examination, class project and additional papers rather than completing them.... Free Essays on Procrastination Free Essays on Procrastination Have you ever put something off to the last minute†¦such as a project or a paper? I’m sure at some point in your life you have. You may procrastinate more than you realize. Procrastination is one of the main reasons that so many companies lose money and you don’t want to be the one losing money for your company. However there are solutions to procrastination and it can be overcome. Today we are going to talk about identifying underlying issues that cause procrastination, developing solutions, and overcoming procrastination. IDENTIFY UNDERLYING ISSUES Discover your pattern of procrastinating and make a note of it. One reason you procrastinate is because of fear. Sometimes you may fear the task or project at hand because you have to move out of your comfort zone. Becoming aware of your fear can enable you to eliminate it. Perfectionism is one of the more common reasons for procrastinating. Perfectionists avoid starting because they fear they will fall short of their highest standard. If they avoid starting they never have to worry about imperfections in the end if the task isn’t done. Crisis Making- one who thrives on adrenaline. Cannot get motivated until the very last moment. Infuriates friends and colleagues and makes you look bad in the process. Expectation anxiety. Stop becoming a better person for other people and realize that the person you are is just fine. Your faults can be wonderful teachers and weaknesses are just hidden strengths. Accept yourself and always do your best. Overextenders often have the har dest time recognizing themselves because everything is important. Set goals for what is to be done and when, break goals into smaller sub-goals. DEVELOPING SOLUTIONS. Face procrastination head on. Ask yourself what is blocking you? Write it down/ record it. This exercise should help you begin. Choose to easily begin. Making this choice is often enough to get you going. In National Public Acco... Free Essays on Procrastination I’m what most people might call lazy, lethargic, and a procrastinator. How did it start? The first specific instance that I can remember was in 5th grade math class. I didn’t do my math. My mentality was that school consumed more then half of my waking hours and I wasn’t going to let it take anymore then that. So my assignments were partially completed, from the day before, and handed in unfinished. I knew that my parents and teachers would raise hell itself when I did this but my mind wouldn’t waiver on this. Since I had been able to get through all of grade school without homework why should I have any now? Great reasoning for a 5th grader, but this thinking contained a few flaws. To start out, there are 3 types of people in the world. The first kind will generally always try their best and be a competitor in life. They treat life as a marathon that needs a steady vigil pace to complete. The second is the person the will try to complete the absolute bear minimum to survive and occasionally misjudges what is needed done. The third and final is the person that absolutely cannot find any reason to try at all and hope for the best to come to them but never actively seek it. This is the lowest form of life that will suckle away your money, forgiveness, and love never sharing it back with you. To thoroughly understand the three classes of people, a more detailed analysis is needed. The first kind is the ideal person. One, which all parents and communities hope to produce. They are considered the leaders, overachievers, and well standing citizens. The second class is the C student of life. They’re the average person who occasionally does exceptional work but for the most part will be in the shadows of the first class. Procrastination and laziness is most common to occur in this class and becomes extreme when we reach the third class. The 3rd class no longer tries or cares too much about their life to do anything about their... Free Essays on Procrastination Procrastination is more than just a negative custom that needs to be weeded out of society; it is also a clichà ©Ã¢â‚¬Å¡ a small-talk joke, boast, or complaint. After all, we all do it. Most everybody I know is willing to admit it is an exasperating problem in their life, and would benefit from a course in How to Eliminate Procrastination, but say they have to much to catch-up on, and will take it later. There are many underlying issues and causes of procrastination. Lack of relevance and interest is two of the most common causes. While perfectionism having extremely high standards, which are almost unreachable is another problem all together. Evaluation, anxiety, ambiguity, fear of failure and self-doubt, fear of success, inability to handle the task, lack of information needed to complete the task, environmental conditions, physical conditions, moreover, and anxiety over expectations that others have of you, are all very serious causes of procrastination. Poor time management is a great cause of procrastination. Procrastination means not managing time wisely. One may be uncertain of one's priorities, goals, and objectives. Procrastinators may also be overwhelmed with the task. As a result, they keep putting off the assignments for a later date, or spending a great deal of time with your friends or worrying about upcoming examination, class project and additional papers rather than completing them....