质量与能量平衡.doc

1 Literature Review:1.1 Ethylene oxideEthylene oxide, also called oxirane, is the organic compound with the formula C2H4O. This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered ring consisting of two carbon and one oxygen atom. It is commonly handled and shipped as a refrigerated liquid.1 It is the chief precursor to ethylene glycol and other high volume chemicals but is also used for medical sterilization.1.2 UsesEthylene oxide is used as sterilant, although the amount used for this purpose is minor compared to the applications in the chemical industry. The gas kills bacteria (and their endospores), mold, and fungi. It is used to sterilize substances that would be damaged by high temperature techniques such as pasteurization. Ethylene oxide is widely used to sterilize the majority of medical supplies such as bandages, sutures, and surgical implements in a traditional chamber sterilization method, where a chamber is flooded with a mixture of ethylene oxide and other gases that are later aerated. The more recent gas diffusion method developed in 1967 relies on a bag that wraps the elements to be sterilized and serves as a mini-chamber in order to minimize gas consumption and make the process economically feasible for small loads. Other names for this alternative method for small loads are the Anprolene method, bag sterilization method or micro-dose sterilization method.2 Straight matter:2.1 QuestionEthylene oxide is produced by oxidation of ethylene with oxygen at circa 250 C over a catalyst comprising metallic silver supported on alumina4. Typically, promoters such as chloride are also included. Pressures used are in the region of 1-2MPa. The overall chemical equation is: r17H2C=CH2 + 6O2-6C2H4O + 2CO2 + 2H2OA side reaction is react at the same time: r2C2H4 + 3O2 - 2CO2 + 2H2OThere is a reactor. The flow of feed material is 1000mole/h and there is 10% Ethylene with mole fraction in the feed material. The conversion rate of Ethylene is 25 %.The rate of the choice of Ethylene generate product is 80%.Please calculate components and flow of the material in the reactors output.2.2 Solution:ComponentC2H4O2N2C2H4OCO2H2ONumber123456Figure 1 Number of the component,2F1=1000mol/hx11,x12,x13F2x21,x22,x23x24,x25,x26r1,r2x11=0.1=0.26581=0.81=0.25ReactorFigure 2 Simple diagram for calculationSymbolMeaningFAmount of Substance of the flow.xMole fractionVThe stoichiometric number of Chemical reaction.rThe reaction rate of chemical reaction.The conversion rateThe rate of the choice of generate productVO2/VN2Figure 3 NotesStep 1,2,3, and 4 All of the symboles and known data have been placed on Figue1 to Figure 3.Step 5 Select as the basis the given feed.Basis: F1=1000mol/h x11=0.1 1=0.25 = VO2/VN2=2658Step 6 The variables whose values are unknown are x12,x13,x21,x22,x23,x24,x25,x26,F2,r2,2.Use the cnditional expression:x11+x12+x13=1x11=0.1=x12/x13=0.2658x12=0.1890x13=0.7110Step 7 and 8 The component balance areFeed inConsumptionOutC2H4F1x11F2x212r1+r2O2F1x12F2x22r1+3r2N2F1x130F3x23C2H4O0-2r1F2x24CO20-2r2F2x25H2O0-2r2F2x26Step 9 Use these component balance,we can make several independent equations.Feed in Consumption Out = 0F1x11 F2x21 2r1 r2 = 0F1x12 F2x22 r1 3r2 = 0F1x12 F2x23 = 0 F2x24 + 2r1 = 0 F2x25 + 2r2 = 0 F2x26 + 2r2 = 0xij = nij/Finij = Fi*xijn11 n21 2r1 r2 = 0n12 n22 r1 3r2 = 0n13 n23 = 0 n24 + 2r1 = 0 n25 + 2r2 = 0 n26 + 2r2 = 0n11 = F1*x11 = 100 mol/hn12 = F1*x12 = 189 mol/hn13 = F1*x13 = 711 mol/h1 = 0.25 = (F1x11 F2x21)/(F1x11)n21 = 75 mol/h = 0.8 = (F2x24)/(F1x11 F2x21)n24 = 20 mol/h100 75 2r1 r2 = 0189 n22 r1 3r2 = 0711 n23 = 0 20 + 2r1 = 0 n25 + 2r2 = 0 n26 + 2r2 = 0 According to the results of the above,we know that:F2 =990 mol/hx21 =0.076x22 =0.166x23 =0.718x24 =0.200x25 =0.010x26 =0.010Step 10 Check to see whether each of the balances is satified or not.After that,we know the result is absolutely correct.3 ResultThe Flow of the material in the reactors output is 990 mol/hThe mole fraction of C2H4 in the reactors output is 0.076.The mole fraction of N2 in the reactors output is 0.166The mole fraction of C2H4O in the reactors output is 0.718The mole frac