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A mixture of 85% n-heptane, remaining toluene gas at 1 bar and 308 K is compressed to a final state at 1205.47 K and 63.73 bar. Estimate the enthalpy and entropy changes for the process using residual properties and by the Lee/Kessler correlations. In its initial state, the system may be assumed an ideal gas.
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A gas contains 55.0 wt% methane, 5.00 wt% ethane, 35.0 wt% ethylene, and the balance water. If 100.0 kg/h of this fuel is to be burned with 30.0% excess air, what is the required air feed rate? in kmol/h What is the required feed rate if the combustion is only 75.0% complete? in kmol/h
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1. You have 5 g of CO2 (w = 0.225) in a 50 mL container, which
is at 723 ° C. Determine the gas pressure using the following
equations and obtain the percentage of error with respect to the
ideal gas:
a) Van der Waals. (3 points)
b) Virial truncated. (3 points)
c) Peng-Robinson. (3 points)
d) Soave-Redlich-Kwong. (3 points)
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Your assignment is to compute how big a square solar collector would have to be in order to provide power to
(1) all the residents of the UAE
(2) all the people of the world.
The power supplied should be equal to the current per capita consumption of the UAE. Assume that all the energy is to be supplied in the form of electricity.
In this assignment, you must specify the sources of all data you used in order to compute your answer.
For example some data you may need include:
Grading:
Report all sources of data --
Units clearly expressed in all calculations
Reasonable values used in all calculations
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A mixture of propane and butane is burned with pure oxygen. The combustion products contain 46.7 mole% H2O. After all the water is removed from the products, the residual gas contains 68.6 mole% CO2 and the balance O2 a. What is the mole percent of propane in the fuel?
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A stream of saturated water at 54 o C at 25 lbm/min and ammonia solution (50 wt%) at 150 lbm/min are fed to a boiler at 1 atm. The enthalpy of the ammonia solution relative to the reference conditions is 125 BTU/lbm. The liquid and vapor products are leaving the system. The liquid composition is to be 13 wt% NH3. Determine the rate at which heat must be transferred to the system. Includes diagram, mass balance, energy balance.
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Describe three ways in which the composition of fuel changes while the reactor is in operation, and how each change affects reactor operation. You may discuss nuclear, chemical, or material changes, or a combination.
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In FCC iron, carbon atoms are located at octahedral sites at the centre of each edge of the unit cell (1/2, 0, 0) and at the centre of the unit cell (1/2, 1/2, 1/2). In BCC iron, carbon atoms enter tetrahedral sites, such as (1/4, 1/2, 0). The lattice parameter is 0.3571nm for FCC iron and 0.2866nm for BCC iron. Assume that carbon atoms have a radius of 0.071nm.
(a) Would we expect a greater distortion of the crystal by an interstitial carbon in FCC or BCC iron?
(b) How is the distortion in FCC and BCC related to solubility of the interstitial carbon? Show your all work of calculation for a credit.
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13. Injury factors important in radiation-caused damage include:
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A sieve-tray tower is being designed for a gas absorption process. The entering gas contain 1.8% (molar) of A, the component to be absorbed. The gas should leave the tower containing 0.1% (molar) of A. The liquid to be used as absorbent initially contains 0.01% (molar) of A. The system obeys Henry’s law with m = yi / xi = 1.41. At the bottom of the tower, the molar liquid-to-gas ratio is 2.115, while at the other extreme it is 2.326. For these conditions, it has been found that the Murphree efficiency is constant at 0.65. Estimate the number of trays required.
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Question 3
A sheathed thermocouple is placed in a combustion chamber to measure the temperature of the gases at a certain point in the process. The thermocouple reading is 1110K and the inside wall temperature was measured at 1008K. The thermocouple has a surface area of 10 mm2 .
(a) A pitot probe is used to measure the velocity of the gas stream in the vicinity of the thermocouple tip. It measures a difference in static and dynamic pressure of 10 Pa. The convection heat coefficient (W/m2K) between the hot gases and the thermocouple is given by a correlation:
h = K.u0.466
where: u is the velocity in m/s
K = empirical constant at high temperature = 50
What is the true gas temperature?
(b) A thermocouple is instead embedded inside the wall of a small conductive tube of inside diameter 20 mm, outside diameter 25 mm and length of 30 mm. The tube and embedded thermocouple are at a uniform temperature of 1110K. Suction is applied to the tube so that hot gas is drawn through the tube at 200 m/s. The heat transfer coefficient between gas and tube can be calculated by the correlation in part (a).
Assume the inside wall temperature of the combustion chamber is still 1008K. What is the true gas temperature? What is the temperature reduction of the gas in passing through the 30mm length of the tube?
Notes:
The Stefan Boltzmann constant is 5.669x10-8 W/m2 .K4 Assume gas density = 0.28 kg/m3 over the entire range of temperatures in this question. Assume gas Cp =1.19 kJ/kg.K over the entire range of temperatures in this question. The emissivity of the thermocouple and radiation shield and combustion chamber walls are all 0.75.
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