Questions and Answers of Introduction To Chemical Engineering

Describe in your own words what the ROI represents. Is it possible for the ROI to be greater than 100%? Justify your answer.
Determine a 2008 delivered purchase price for the items listed below. The M&S index for 2008 is 1449.a. A tank with a volume of 500,000 gal.b. A heat exchanger with an area of 3500 ƒt2.c. A
Define each of the following: NAPAT, ROI, ϕ
Your assignment is to determine the return on investment for an ammonia plant that is being considered for construction.The plant will produce 55,650 kg/hr of ammonia, which sells for $0.60/kg. The
What would the total cost for the two water heaters in Table 13.1 have been if figured for a lifetime of 5 years instead of 10 years? Table 13.1 Capital and Operating Costs for Two Hypothetical Water
Name at least one example of conduction, convection, and radiation from everyday life.
Name three examples of heat exchangers that are part of your everyday life.
The exhaust gas coming from a coal-burning furnace (flue gas) usually contains sulfur in the form of SO2, and when the gas is discharged into the atmosphere (which sometimes happens), the SO2 can
In this chapter, we mention that problems arise from having at least two systems of units in the industrialized world (i.e., the metric system and the American engineering system). In more specific
The following variables are given in the following units:In terms of these variables, which of the following obey the laws of dimensional consistency? (Support your answers)a.b.where J0 has the same
A 6M sulfuric acid solution (H2SO4 in water) is flowing into a tank at the rate of 100 liters/min (also can be written 100 L/min). The density of the solution is 1.34 g/cm3. Determine the value of
Explain the origin of Equation (e) in Example 5.7. What information in the problem statement was used in writing this relationship? What does rconsumption, butene represent physically? EXAMPLE
A stream consisting of two organic chemicals: (1) benzene (C6H6) and (2) toluene (C7H8), enters a separation column. The total mass flow rate of the stream is 10,000 lbm/hr. The mass percent of
The weight of an astronaut is measured on a distant planet and found to be one-fifth of his weight on Earth’s surface. Is his mass different on that distant planet than on Earth? What does the
A piston is movable (up and down) inside a vertical cylinder as shown below. The pressure beneath the piston is greater than the pressure on top of the piston, and this difference in pressure can
In an attempt to compute the number of seconds equivalent to 36 minutes, your colleague obtains for an answer 0.6 min2/s. What did your colleague do wrong?
When a fluid flows from one location (“start”) to another location (“end”) under certain circumstances, the changes in fluid properties can be described by the Bernoulli equation, which
Using water and air as examples, what is an approximate ratio of the densities of liquids to gases?
Two compounds, one with a high molecular weight and one with a low molecular weight, are flowing at the same mass flow rate. Which has the greater molar flow rate?
What assumptions are inherent in Equation 5.3? When do such assumptions not apply?Equation 5.3 min = input streams Σ moud out put streams
Two compounds, one with a high density and one with a low density, are flowing at the same mass flow rate. Which has the greater volumetric flow rate?
Two compounds, one with a high molecular weight and one with a low molecular weight, each comprise 50 mole% of the same mixture. Which has the greater mass fraction in the mixture?
Two streams of similar liquid mixtures enter the center of a distillation column. The action of the column separates the combined mixture into several components of different volatilities (and
Feed water is fed to a large steady-state boiler. Most of the water leaves the boiler as high-pressure steam, with a smaller amount of hot residual water discharged to waste. The water densities and
Solution 1 has a greater density than does solution 2, and solution 1 also has a greater concentration of species A than does solution 2. For these solutions, answer each of the following questions
Suppose that you have a process that converts nitrogen and hydrogen into ammonia by the following chemical reaction:a. For this process, is it correct to write a total mole balance such as Why, or
A solution of salt dissolved in water is diluted with additional water. With each of the following variables, indicate whether the dilution process will cause the value of the variable to increase,
In what way(s) can a material balance on a particular chemical compound differ from a total material balance?
Human lungs transfer oxygen fromair to blood due to cyclic inhaling and exhaling, but over time, the process can be considered to be steady-state. As air enters the lungs, it contains a large amount
To make an industrial solvent, benzene (C6H6) is provided at a molar flow rate of 1140 kgmol/hr. Toluene (C7H8) is also added to the benzene at a rate of 213 kgmol/hr to enhance the solvent
In a candy company, separate streams of sugar, butter, corn syrup, cocoa, vanilla extract, and milk enter a mixer-boiler and come out as fudge. The sugar (sucrose, C12H22O11) is purchased from a
Suppose that you (as a chemical engineer) have been asked to design a treatment facility for a hazardous waste stream. How might material balances be used to help you with your design?
An “absorber” is a device used to bring a gas containing toxic chemicals into contact with a liquid that absorbs some of those toxic chemicals from the gas. Thus, a gas stream and liquid stream
A manufacturing plant located in a narrow canyon has applied to the Environmental Protection Agency (EPA) for a permit to continuously release 15ƒt3/min of exhaust gas, containing 0.06 gmol/ƒt3 of
A solution of NaOH in water flows in a stream, and the mass flow rate of the stream is suddenly increased. For each of the following properties of the stream, indicate whether the increase in flow
A common medical problem in today's world is a disease of the arteries that feed our heart muscle (called "coronary arteries") that results in narrowing of the arterial diameter and reduced blood
The left side of the mechanical energy equation (Equation 7.8a) has three terms: P/ρ, 1/2∝v2, and gz. Show that each of these terms has the dimensions of energy per mass of fluid byEquation 7.8aa.
Construct an Excel spreadsheet to help make cylindrical containers by drilling out aluminum cylindersThe constraints:• The drilled-out volume must be 85 cm3.• A minimum wall and bottom thickness
Because of environmental considerations, acetone must be removed from air used in your chemical plant before the air is released into the atmosphere. The acetone is removed by absorbing it into water
A mixture of ethylbenzene, para-xylene, meta-xylene and ortho-xylene enters a separation system at a rate of 10,000 kg/hr. Three streams leave the separator. The first exit stream has a flow rate of
For the combustion of methane presented in Example 5.4, the chemical reaction isSuppose that methane flows into a burner at 30 gmol/s, while oxygen flows into the same burner at 75 gmol/s. If all the
A stream of pure species A (50 kgmol/hr) and a stream of pure species B (5 kgmol/hr) enter a reactor where the A is converted to B according to the reaction 2A →B If the molar flow rate of A in the
A chemical process is used to convert toluene (MW = 92) and hydrogen to benzene (MW = 78) and methane (CH4) by the reactionTwo streams enter the process. The first input stream is pure liquid
Fuel cells have been proposed for use in cars and for power generation as part of a hydrogen economy. They offer the advantages of higher efficiency (not limited by heat cycle efficiencies) and
In the fabrication of semiconductors, one step is the formation of additional gallium arsenide (GaAs) on the surface of a GaAs wafer. To accomplish this, gaseous tri-methyl gallium (TMG) and arsine
Ammonia is used for fertilizer production and has been critical to successful agriculture. A steady-state chemical process is used to convert nitrogen (N2) and hydrogen (H2) to ammonia (NH3) by the
Produce the spreadsheet in Figure 6.4 by following the steps outlined in the reading and turn in the results. 1234567890123 A B Conc. Flow (mm) (L/hr) NaOH Costs Price D Cost ($/L)
Students and faculty from Brigham Young University developed and delivered a small-scale process to Tonga for making biodiesel fuel from coconut oil. The central component of the process was the
Write the Excel expression for performing the calculation indicated by each of the following algebraic expressions:a.b.c. [15.1 tan (0.71)]4.3
What was the advantage of entering the given information about the HCl concentration and flow rate, the NaOH price formula, and the NaOH pumping cost in their own cells rather than simply building
Use a spreadsheet to estimate the accumulation in your retirement account during 20 years of your career as a chemical engineer. Turn in the spreadsheet along with the answers to the questions posed
Produce the chart in Figure 6.6 by following the appropriate steps (e.g., those in Table 6.4). $8,000 $7,000 NaOH Total $6,000 Cost $5,000 $4,000 0.0 10.0 50.0 20.0 30.0 40.0 NaOH Conc. (mM) Figure
In terms of molecular spacing, would you expect gases or liquids to be more compressible? Explain your answer.
A pressure-measuring device indicates that the blood pressure of a normal person oscillates between 120 mm Hg (at the peak of the heartbeat) and 80 mm Hg (between heartbeats).When the
For a stagnant liquid, how will the pressure at the bottom compare (greater or lesser) with the pressure at the top? In terms of physical forces, why do you think this is so?
Consider a liquid (constant density) pumped steadily along a pipe of constant diameter.a. We know from Chapter 5 that the mass flow rate into any section of the pipe must equal the mass flow rate out
If the pressure at a depth of 8ƒt below the surface of a stagnant liquid is 3.5 psi above atmospheric pressure, what will the pressure of the liquid be at a depth of 48ƒt below the surface? Write
Two immiscible liquids sit in a closed tank as shown below.The gas above the top liquid is at an absolute pressure of pg. Furthermore, the densities and heights of liquid 1 and liquid 2 are ρ1 and
What were two drawbacks associated with the idea of using the pressure at the bottom of the NaOH tank to drive the flow of NaOH to where it will join the HCl?
One way to drain a liquid out of a container that has high walls is to use a siphon: a tube is placed with one end in the liquid and the other end over the wall of the container as shown on the next
Which kind of pump, a centrifugal pump or a positivedisplacement pump, would you recommend for use in a home dishwasher or washing machine? Support your answer.
As you tour a chemical-processing facility, you observe that a piston-cylinder pump moves a toxic heavy oil through a piping system in that facility. What is the purpose of a rupture disc surrounded
A venturi meter is a device placed in a pipeline to allow for the measurement of flow through that pipeline. As shown in the following figure, the meter consists of a tapered reduction of the pipe
A turbine operates by the impact of a high-velocity jet of steam against the turbine blades. The steam leaves the turbine at a lower velocity. For the turbine depicted below, steam from a
In a hemodialyzer (artificial kidney), blood (density = 1.06 g/cm3) flows through a bundle of hollow fibers, a salt solution flows around the outside of the fibers, and waste products transfer from
A system consisting of a pump and pipeline is being designed to deliver water (density = 62.4 lbm/ƒt3) from a reservoir in the mountains down to the city 2800 ƒt below. The water must arrive at a
You have been asked to determine the power for a pump to deliver water (rwater = 62.4 lbm/ft3) over a hill that is 2500 ft high at its peak to a holding tank on the other side as shown below. The
In view of Equations 8.1 and 8.4, which describe molecular diffusion and mass convection, respectively, how would the rate of each type of transfer change if the difference in concentration of
Some discarded solid chemical waste dissolves slowly in a large drain pipe in which the water is stagnant. On a particular day, the dissolved chemical has a concentration of 0.16 M near the solid and
Consider the mass convection of species A from an interface into a flowing stream of species B as in Figure 8.4. How would each of the following affect the rate of that convection? In each case,
For the molecular diffusion of species A through species B, how would each of the following affect the rate of that diffusion? In each case, explain your answer.a. The temperature of the mixture is
The binary diffusivity of a particular salt in water at room temperature is 3.2 × 10−4 cm2/s. That salt in solid form dissolves at the bottom of a beaker of water (8 cm high), while water flows
Which concentration difference is driving mass transfer for each of the following:a. A solid block of salt slowly dissolves in a stagnant pool of water.b. A quantity of a drug has been injected into
Indomethacin (an anti-inflammatory drug, MW=357.79) is to be delivered by a surgically implanted drug-delivery device in which the drug inside a membrane reservoir transfers through the membrane to
Your company manufactures hemodialyzers that have the characteristics described in Example 8.3. A colleague in the company has proposed replacing the membranes with better ones, which have the same
Molecules of a drug move through a polymer membrane and into blood that flows next to the membrane.a. What kind of mass transfer (molecular diffusion, or convection) occurs in the polymer, and which
The intermediate product of a chemical process is a chemical paste that is saturated with water. The paste is rolled into a thin layer and placed to dry in a flat area 30 m long by 15 m wide. Drying
Consider the gas-phase reactionHow would each of the following affect the rate of that reaction?Explain each answer.a. The temperature of the reaction is increased.b. The pressure of the reaction is
Show that for a rate equation of the form given in Equation 9.1, the units of kr areEquation 9.1where n and m are the exponents of the concentrations as shown in that equation. (moles)¹-n-m
Show that for a rate equation of the form given in Equation 9.2 with the rate in units of pressure/time, the units of kr areEquation 9.2where n and m are the exponents of the concentrations as shown
In your company, a particular reaction is produced in a CSTR. The design group has come to you for advice concerning the building of a new plant using this reaction. They propose to use a reactor
A reaction vessel is filled with a solution at 22.9°C containing sulfuric acid and diethyl sulfate. The following reaction is first-order in each reactant and occurs with an irreversible reaction
Suppose that the acid-neutralization process is carried out by joining together the pipelines from the acid and base tanks without the recommended inline mixer. Suppose further that pH meters were
A prevalent form of toxic pollutant NOx formed in powerplant combustors is NO. Under favorable conditions, NO can be decomposed (“reduced”) via the following reaction:At 1620 K, for a reaction
For the acid-neutralization process, we calculated the reactor size required for a reaction temperature of 25°C. Estimate the reactor volume for a reaction temperature of 5°C (a cold winter day)
As an engineer in a production facility, your assignment is to specify the size of a reactor needed to react a liquid stream(33 L/min) containing species G (concentration = 0.19 M). The goal is to
Butadiene sulfone (MW=118) can be produced by the following irreversible liquid-phase reaction at 190°F and 160 psia:Butadiene + SO2 → Butadiene SufonePure SO2 is fed to the reactor in one
As a chemical engineer working for MedAid, Inc., you are assigned to size a reactor for producing Agent X, a new chemical designed to combat killer viruses. X is produced by the following
Verify that Equation 10.23 follows from Equations 10.21 and 10.22 by performing the derivation using the assumptions summarized in the paragraph before Equation 10.22.Equation 10.23Equation 10.21 and
A freshman chemical engineering student is walking across campus on a cold winter day. For each of the following scenarios, which forms of heat transfer (conduction, convection, and/or radiation) are
To what extent does radiation heat transfer require the presence of a medium in order for the transfer to occur? How does this differ from conduction or convection heat transfer?
A stream of bread dough is fed steadily through an oven in a large bread-baking operation. The dough enters the oven at a rate of 110 ƒt3/hr and at a temperature of 70°F. It exits the oven at
In the calculation to determine the outlet temperature of the acid-neutralization process.a. Rework the problem to find the outlet temperature assuming no heat is transferred to/from the surroundings
Compare Equation 10.5 with Equation 8.1. How are they similar? How are they different?Equation 10.5Equation 8.1 T - T X2 – X| ¿cond x = —ΚΑ· –ΚΑ· ΔΙ Δι
A liquid solution is passed steadily through an infrared radiative oven to sterilize it. The system is horizontal (no elevation change), and the velocities are small. Furthermore, the density of the
Compare Equation 10.6 with Equation 8.4. How are they similar? How are they different?Equation 10.6Equation 8.4 Oconv = hA (Tsur face - Thulk fluid)
One method to estimate the flow rate of blood delivered by the heart (called the "cardiac output") is to continuously inject a dye into the artery (aorta) entering the main circulatory system and
One method of producing drinkable water is to force sea water through a membrane that does not allow the salt to pass through. A large facility continuously filters 2300 L of sea water per hour. The
Gas in a tank contains a poison at a concentration cT, but the gas is leaking into the surrounding room at a rate of T cm3/min. Meanwhile, an air conditioner brings fresh air into the room at a rate
What was the advantage of using the formula =I$3*I$2/A5 rather than =I3*I2/A5 when preparing formulas for all the cells?

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