Questions and Answers of Chemical Biochemical And Engineering

Steam is available at 2 MPa and 800◦C. a. Determine the maximum amount of shaft work that can be obtained from this steam in a flow process if the ambient conditions are 25◦C and 1 bar. b. This
Which has the greater potential to produce more available work steam at 2 MPa and 800◦C or steam at 1.4 MPa and 900◦C?
a. Derive the equations analogous to Eqs. 4.6-6 and 8 for the nonflow available work. Eqs. 4.6-6Eqs. 4.6-8b. Derive the integrated forms of these equations for an ideal gas of constant heat capacity
A stream of flowing air is available at 25 bar and 1000◦C or at 40 bar and 900◦C. Assuming air is an ideal gas with a constant pressure heat capacity of 29.7 J/mol K, which stream has the greater
It is desired to improve the thermal efficiency of the Rankine power generation cycle. Two possibilities have been suggested. One is to increase the evaporator temperature, and the second is to
a. An automobile air conditioner uses the vapor compression refrigeration cycle with HFC-134a as the refrigerant. The operational temperature of the evaporator is 7◦C and that of the condenser is
Using a T-Ŝ diagram, discuss the effect of subcooling in the condenser and superheating in the evaporator on the efficiency of a Rankine (or other) power generation cycle.
Forest cabins, remote mobile homes, Amish farms, and residential structures in locations where electricity is not available are often equipped with absorption refrigerators that rely on changes from
A power plant using a Rankine power generation cycle and steam operates at a temperature of 80◦C in the condenser, a pressure of 2.5 MPa in the evaporator, and a maximum evaporator temperature of
As in Illustration 5.1-1 it is desired to produce liquefied methane; however, the conditions are now changed so that the gas is initially available at 1 bar and 200 K, and methane leaving the cooler
a. Nitrogen can be liquefied using a simple Joule Thomson expansion process. This is done by rapidly and adiabatically expanding cold nitrogen from a high-pressure gas to a low-temperature,
A Rankine steam cycle has been proposed to generate work from burning fuel. The temperature of the burning fuel is 1100◦C, and cooling water is available at 15◦C. The steam leaving the boiler is
Electrical power is to be produced from a steam turbine connected to a nuclear reactor. Steam is obtained from the reactor at 540 K and 36 bar, the turbine exit pressure is 1.0 bar, and the turbine
High-pressure helium is available from gas producers in 0.045-m3 cylinders at 400 bar and 298 K. Calculate the explosion equivalent of a tank of compressed helium in terms of kilograms of TNT. Assume
The United States produces about 2700 megawatts (MW) of electricity from geothermal energy, which is comparable to burning 60 million barrels of oil each year. Worldwide about 7000 MW of geothermal
The “Quick Fill” bicycle tire filling system consists of a small (2 cm diameter, 6.5 cm long) cylinder filled with nitrogen to a pressure of 140 bar. Estimate the explosion equivalent of the gas
A Rankine power generation cycle is operated with water as the working fluid. It is found that 100 MW of power is produced in the turbine by 89 kg/s of steam that enters the turbine at 700◦C and 5
A tank containing liquid water in equilibrium with a small amount of vapor at 25 bar suddenly ruptures. Estimate the fraction of liquid water in the tank that flash vaporizes, and the explosive
During methane liquefaction, about 1000 kg of methane are stored at a pressure of 10 MPa and 180 K. The plant manager is worried about the possibility of explosion. Determine the energy released by a
An Automobile engine can be modelled as an idealized four-stroke Otto cycle, although it actually consists of 6 steps: Step 0: A fuel-air mixture is drawn into a cylinder at constant pressure
N-butane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at 25◦C and 1 bar, it will be compressed to 15 bar in a compressor that has an isentropic efficiency of 85%,
One suggestion that has been made to conserve energy is that all new electrical power generation plants should be co-generation facilities. In a typical power plant the combustion of coal or natural
Isobutane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at 25◦C and 1 bar, it will be compressed to 15 bar, cooled to 0◦C in a heat exchanger, and expanded and
Repeat the calculation of problem 5.22 with the vapor being recycled to the compressorProblem 5.22Isobutane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at 25◦C
Repeat the calculation of problem 5.22 if the compressor has an isentropic efficiency of 72%. Problem 5.22Isobutane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at
Repeat the calculation of problem 5.23 if the compressor has an isentropic efficiency of 87%.Problem 5.23Repeat the calculation of problem 5.22 with the vapor being recycled to the compressorProblem
The inlet to an adiabatic turbine is steam at 0.8 MPa and 350◦C, and the turbine exit pressure is 0.1 MPa. a. Determine the maximum work that can be obtained from each kg of steam and the exit
Redo Problem 5.20 using Aspen Plus.Problem 5.20N-butane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at 25◦C and 1 bar, it will be compressed to 15 bar in a
Redo Problem 5.22 using Aspen Plus.Problem 5.22 Isobutane is to be liquefied to make liquid petroleum gas (LPG). The butane is available at 25◦C and 1 bar, it will be compressed to 15 bar, cooled
Redo Problem 5.23 using Aspen Plus.Problem 5.23Repeat the calculation of problem 5.22 with the vapor being recycled to the compressorProblem 5.22Isobutane is to be liquefied to make liquid petroleum
Redo Problem 5.27 using Aspen Plus.Problem 5.27Methane at 260 K is to be isothermally compressed from 0.1 MPa to 1.0 MPa. a. What is the minimum work required, and how much heat must be removed to
Derive the following Maxwell relations for open systems. a. Starting from Eq. 6.2-5a,b. Starting from Eq. 6.2-6a, c. Starting from Eq. 6.2-7a,d. Starting from Eq. 6.2-8a, (т). HT ON ӘР (0) aN S,
For real gases the Joule-Thomson coefficient is greater than zero at low temperatures and less than zero at high temperatures. The temperature at which μ is equal to zero at a given pressure is
Steam is continuously expanded from a pressure of 25 bar and 300°C to 1 bar through a Joule-Thomson expansion valve. Calculate the final temperature and the entropy generated per kilogram of steam
In the calculation of thermodynamic properties, it is convenient to have the following partial derivatives: where Z = (PV /RT) is the compressibility factor. Develop expressions for these two
The Boyle temperature is defined as the temperature at which the second virial coefficient B is equal to zero. a. Recognizing that any equation of state can be expanded in virial form, find the Boyle
In a continuous manufacturing process, chlorodifluoromethane (CHClF2), initially at 10 bar and 420 K, passes through an adiabatic pressure-reducing valve so that its pressure drops to 0.1 bar (this
A gas is continuously passed through an adiabatic turbine at the rate of 2 mol/s. Its initial temperature is 600 K, its initial pressure is 5 bar and its exiting pressure is 1 bar. Determine the
Methane at 260 K is to be isothermally compressed from 0.1 MPa to 1.0 MPa. a. What is the minimum work required, and how much heat must be removed to keep the compression process isothermal? b. If
The inlet to an adiabatic compressor is nitrogen at 1 bar (0.1 MPa) and 150 K, and the exit pressure is 10 bar (1 MPa). a. Determine the minimum work required for each kg of nitrogen compressed and
Two separate experiments are performed on a gas enclosed in a piston-and-cylinder device, both starting from the same initial state. The result of the first experiment is to be used to predict the
Redo Problem 5.2 using Aspen Plus.Problem 5.2t is desired to improve the thermal efficiency of the Rankine power generation cycle. Two possibilities have been suggested. One is to increase the
Redo Problem 5.1 using Aspen Plus.Problem 5.1a. An automobile air conditioner uses the vapor compression refrigeration cycle with HFC-134a as the refrigerant. The operational temperature of the
Redo Problem 5.4 using Aspen Plus.Problem 5.4A power plant using a Rankine power generation cycle and steam operates at a temperature of 80◦C in the condenser, a pressure of 2.5 MPa in the
Redo Problem 5.7 using Aspen Plus.Problem 5.7A Rankine steam cycle has been proposed to generate work from burning fuel. The temperature of the burning fuel is 1100◦C, and cooling water is
A natural gas stream (essentially pure methane) is available at 310 K and 14 bar. The gas is to be compressed to 345 bar before transmission by underground pipeline. If the compression is carried out
Redo Problem 5.28 using Aspen Plus.Problem 5.28The inlet to an adiabatic turbine is steam at 1.3 MPa and 385◦C, and the turbine exit pressure is 0.1 MPa. a. Determine the maximum work that can be
Derive Eqs. 6.4-29 and 6.4-30. T H(T, P) - HG (T, P) = RT(Z - 1) + and IG S(T.P) - S¹ (T, P) = RIn(Z - B) + da dT 2√/2b da
Redo Problem 5.29 using Aspen Plus.Problem 5.29The inlet to an adiabatic compressor is nitrogen at 1 bar (0.1 MPa) and 150 K, and the exit pressure is 10 bar (1 MPa). a. Determine the minimum work
Derive Eq. 6.6-11. Pr,Tr S(T,P)-SIG (T, P) = - R R S Pr=0,Tr (OZ.) P.] Z-1 Tr ᎧᏃ + Pr Pr dP (6.6-11)
For steam at 500◦C and 10 MPa, using the Mollier diagram, a. Compute the Joule-Thomson coefficient μ = (∂T/∂P)H. b. Compute the coefficient κS = (∂T/∂P)S. c. Relate the ratio
Evaluate the difference for the ideal and van der Waals gases, and for a gas that obeys the virial equation of state. (3²) - (0)₁ P V
A tank containing carbon dioxide at 400 K and 50 bar is vented until the temperature in the tank falls to 300 K. Assuming there is no heat transfer between the gas and the tank, find the pressure in
By measuring the temperature change and the specific volume change accompanying a small pressure change in a reversible adiabatic process, one can evaluate the derivative (SP) and the adiabatic
One hundred cubic meters of carbon dioxide initially at 150◦C and 50 bar is to be isothermally compressed in a frictionless piston-and-cylinder device to a final pressure of 300 bar. Calculatei.
Prove that the following statements are true. a. (∂H/∂V )T is equal to zero if (∂H/∂P)T is equal to zero. b. The derivative (∂S/∂V )P for a fluid has the same sign as its coefficient of
Values of the virial coefficients B and C at a fixed temperature can be obtained from experimental PV T data by noting thata. Using these formulas, show that the van der Waals equation leads to the
a. Show for the Peng-Robinson equation of state (Eq. 6.4-2) thatEq. 6.4-2.b. Determine the critical compressibility of the PengRobinson equation of state. P = RT V-b a(T) V(V+b) + b(V - b) (6.4-2)
From experimental data it is known that at moderate pressures the volumetric equation of state may be written as where the virial coefficient B is a function of temperature only. Data for nitrogen
The Clausius equation of state is a. Show that for this volumetric equation of state b. For a certain process the pressure of a gas must be reduced from an initial pressure P1 to the final pressure
By measuring the temperature change accompanying a differential volume change in a free expansion across a valve and separately in a reversible adiabatic expansion, the two derivatives (∂T/∂V )H
Ethylene at 30 bar and 100°C passes through a heaterexpander and emerges at 20 bar and 150°C. There is no flow of work into or out of the heater-expander, but heat is supplied. Assuming that
Derive the equations necessary to expand Illustration 6.4-1 to include the thermodynamic state variables internal energy, Gibbs energy, and Helmholtz energy.Illustration 6.4-1Making of a
Draw lines of constant Gibbs and Helmholtz energies on the diagrams of Illustration 6.4-1Illustration 6.4-1Making of a Thermodynamic Properties Chart As an introduction to the problem of constructing
The speed of propagation of a small pressure pulse or sound wave in a fluid, vS, can be shown to be equal towhere ρ is the molar density. a. Show that an alternative expression for the sonic
Repeat the calculations of Problem 6.13 if the mechanical efficiency of the adiabatic turbine is only 85 percent.Problem 6.13Eighteen kilograms of the refrigerant HFC-134a at 150°C is contained in a
Nitrogen is to be isothermally compressed at 0°C from 1 bar to 100 bar. Compute the work required for this compression; the change in internal energy, enthalpy; Helmholtz and Gibbs energies of the
For an isothermal process involving a fluid described by the Redlich-Kwong equation of state, develop expressions for the changes in a. Internal energy b. Enthalpy c. Entropy in terms of the
Any residual property θ is defined to bewhere IG denotes the same property in the ideal gas state. Such a quantity is also referred to as a departure function.a. Develop general expressions for
In statistical mechanics one tries to find an equation for the partition function of a substance. The canonical partition function, Q(N,V,T), is used for a closed system at constant temperature,
Redo Problem 6.22 with the Soave–Redlich-Kwong equation of state.Problem 6.22A tank containing carbon dioxide at 400 K and 50 bar is vented until the temperature in the tank falls to 300 K.
a. Show for the Soave–Redlich-Kwong equation of state (Eq. 6.4-1) thatb. Show that the critical compressibility of the Soave–Redlich-Kwong equation of state is 1/3. a(T) = 0.427 48- -a
Derive the expressions for the enthalpy and entropy departures from ideal gas behavior (that is, the analogues of Eqs. 6.4-29 and 6.4-30) for the Soave–Redlich-Kwong equation of state. T IG H(T, P)
Redo Problem 6.7 with the Soave–Redlich-Kwong equation of state.Problem 6.7One hundred cubic meters of carbon dioxide initially at 150°C and 50 bar is to be isothermally compressed in a
Redo Problem 6.12 with the Soave–Redlich-Kwong equation of state.Problem 6.12Ethylene at 30 bar and 100°C passes through a heaterexpander and emerges at 20 bar and 150°C. There is no flow of work
The second virial coefficient B can be obtained from experimental PVT data or from an equation of state from a. Show that for the Redlich-Kwong equation the second virial coefficient is b. Compute
Use the information in Illustration 6.4-1 and the Soave–Redlich-Kwong equation of state to compute the thermodynamic properties of oxygen along the following two isotherms: a. 155 K b. 200
Using the Redlich-Kwong equation of state, compute the following quantities for nitrogen at 298.15 K. a. The difference CP − CV as a function of pressure from low pressures to very high
The Joule-Thomson coefficient, μ, given by is a function of temperature. The temperature at which μ = 0 is known as the inversion temperature. a. Use the van der Waals equation of state to
Repeat Problem 5.9 assuming that helium is described by the Peng-Robinson equation of state.Problem 5.9High-pressure helium is available from gas producers in 0.045-m3 cylinders at 400 bar and 298 K.
Using the Redlich-Kwong equation of state, compute and plot (on separate graphs) the pressure of nitrogen as a function of specific volume at the two temperatures: a. 110 K b. 150 K
Repeat Problem 5.10 assuming that nitrogen is described by the Peng-Robinson equation of state.Problem 5.10The “Quick Fill” bicycle tire filling system consists of a small (2 cm diameter, 6.5 cm
In this chapter, from the third law of thermodynamics, it has been shown that the entropy of all substances approaches a common value at 0 K (which for convenience we have taken to be zero). This
A fluid is described by the Clausius equation of state where b is a constant. Also, the ideal gas heat capacity is given by For this fluid, obtain explicit expressions for a. A line of constant
A piston-and-cylinder device contains 10 kmol of npentane at −35.5°C and 100 bar. Slowly the piston is moved until the vapor pressure of n-pentane is reached, and then further moved until 5 kmol
Develop an expression for how the constant-volume heat capacity varies with temperature and specific volume for the Peng-Robinson fluid. P = RT aa Vm-b V2+2bVm – b²
A manuscript recently submitted to a major journal for publication gave the following volumetric and thermal equations of state for a solid: where a, b, c, d, and e are constants. Are these two
The following equation of state describes the behavior of a certain fluid: where the constants are a = 10−3 m3 K/(bar mol) = 102 (J K)/(bar2 mol) and b = 8 × 10−5 m3/mol. Also, for this fluid
Redo Problem 4.45 if ethylene is described by the truncated virial equation with B (T) = 5.86 · 10−5 − 0.056/T m3/mol and T in K.Problem 4.45The second virial coefficient B can be obtained from
A bicycle pump can be treated as a piston-and-cylinder system that is connected to the tire at the “closed” end of the cylinder. The connection is through a valve that is initially closed, while
The Euken coefficient ξ is defined as ξ = (∂T/∂V)U. a. Show that the Euken factor is also equal to b. What is the value of the Euken coefficient for an ideal gas? c. Develop an explicit
The van der Waals equation of state with a = 0.1368 Pa m3/mol2 and b = 3.864 × 10−5 m3/mol can be used to describe nitrogen.a. Using the van der Waals equation of state, prepare a graph of
Redo Problem 4.45 if ethylene is described by the Peng-Robinson equation of state.Problem 4.45The second virial coefficient B can be obtained from experimental PVT data or from an equation of state
a. Show that b. Use the result of part (a) to show that for a stable system at equilibrium (∂V /∂T)S and (∂V /∂T)P must have opposite signs. c. Two separate measurements are to be performed
Gasoline vapor is to be recovered at a filling station rather than being released into the atmosphere. In the scheme we will analyze, the vapor is first condensed to a liquid and then pumped back to
A 3-m3 tank is in the basement of your house to store propane that will be used for home and water heating and cooking. Your basement, and therefore the contents of the tank, remain at 20°C all
Steam is produced at 70 bar and some unknown temperature. A small amount of steam is bled off just before entering a turbine and goes through an adiabatic throttling valve to atmospheric pressure.
A well-insulated, 0.7-m3 gas cylinder containing natural gas (which can be considered to be pure methane) at 70 bar and 300 K is exhausted until the pressure drops to 3.5 bar. This process occurs
Pipelines are used to transport natural gas over thousands of miles, with compressors (pumping stations) at regular intervals along the pipeline to compensate for the pressure drop due to flow.
How much entropy is generated per mole of chlorodifluoromethane that passes through the pressurereducing valve of the previous problem?Data From Previous ProbemIn a continuous manufacturing process,

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