The company you work for has decided to enter the formaldehyde market. It has asked a...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
The company you work for has decided to enter the formaldehyde market. It has asked a design team, which includes you, to come up with an initial process design to explore the viability of this commercial opportunity. Formaldehyde, HCHO, can be produced by the reaction of methane and oxygen: CH4 + O₂ →HCHO + H₂O Simultaneously, a less desirable side reaction takes place which generates carbon dioxide: CH4 +202 CO₂ + 2H₂O Your colleagues in the design team have proposed a process design, described below, for the production of formaldehyde. They have asked you, as the process analysis expert in the team, to analyse this process to assess its performance before going ahead to do further more detailed design work, with the eventual goal of building the plant. The process consists of a reactor in which the above reactions take place. From ex- periments in their laboratory, the chemists in your team have determined that, at a temperature of 550 °C, the single pass percentage conversion of methane is 14% and the selectivity of formaldehyde generation to carbon dioxide generation is 26. For this process, two feed streams are available. The first provides the methane and the second is air (78% N₂, 21% O2, 1% Ar). The methane stream is the output of a purifi- cation stage from biogas, not considered here. The methane stream has a composition of 92% CH4, 7% O2, and 1% CO2, flowing at a rate of (100+ xy) mol h-¹ where xy are the last two digits of your student ID number. The air stream has a flow rate of 150 mol h-¹. The effluent of the reactor is sent to a flash unit. In this unit, the feed is cooled, resulting in a vapour phase mixture in equilibrium with a liquid phase mixture. The light gases (nitrogen, argon, and oxygen) all end up in the vapour phase. All of the water ends up in the liquid phase. The remaining species are distributed over both phases: 98% of the molar flow rate of methane in the reactor effluent ends up in the vapour phase, along with 87% of the carbon dioxide and 14% of the formaldehyde. The remaining amounts of the methane, carbon dioxide, and formaldehyde are in the liquid phase. The flash unit has two output streams. The first output stream consists of the vapour phase of the two phases that result from cooling the feed to the flash unit. The second output stream comes out of the bottom of the flash unit and consists of the liquid phase. The vapour output stream of the flash vessel is considered a waste product of the whole process. The liquid output stream of the flash vessel is sent to a distillation column which separates the stream into the tops output stream, primarily formaldehyde, and a bottoms product stream which is primarily water. 95% of the formaldehyde fed to this unit ends up in the tops product stream and 95% of the water ends up in the bottoms product stream. The methane and carbon dioxide appear only in the tops product stream. The tops output stream is destined to be the product stream for sale in the formaldehyde market. The bottoms output stream is another waste stream of the process. The following questions must be answered. In answering these questions, show all work, cite all sources of data (including the text book), and make sure to carry units of measure throughout your calculations. The marks (for a total of 100) for each question are indicated in the right margin. 1. Draw and fully label the process diagram. 2. Perform a degree of freedom analysis and demonstrate that you have sufficient information to determine the component flow rates of all streams in the process. 3. Determine the component flow rates of all streams in the process. 4. Assume that the feed streams are fed at ambient conditions (25 °C and 1 bar pressure) as vapour and that the reactor is to operate at 550 °C with the effluent coming out as vapour at this temperature. Use a temperature of 25 °C and pressure of 1 bar as reference conditions for enthalpy calculations to perform the following tasks: i) Determine the inlet-outlet table for the reactor. ii) What are the standard heats of reaction for the two reactions? iii) At what rate should heat be added or removed from the reactor during oper- ation? The company you work for has decided to enter the formaldehyde market. It has asked a design team, which includes you, to come up with an initial process design to explore the viability of this commercial opportunity. Formaldehyde, HCHO, can be produced by the reaction of methane and oxygen: CH4 + O₂ →HCHO + H₂O Simultaneously, a less desirable side reaction takes place which generates carbon dioxide: CH4 +202 CO₂ + 2H₂O Your colleagues in the design team have proposed a process design, described below, for the production of formaldehyde. They have asked you, as the process analysis expert in the team, to analyse this process to assess its performance before going ahead to do further more detailed design work, with the eventual goal of building the plant. The process consists of a reactor in which the above reactions take place. From ex- periments in their laboratory, the chemists in your team have determined that, at a temperature of 550 °C, the single pass percentage conversion of methane is 14% and the selectivity of formaldehyde generation to carbon dioxide generation is 26. For this process, two feed streams are available. The first provides the methane and the second is air (78% N₂, 21% O2, 1% Ar). The methane stream is the output of a purifi- cation stage from biogas, not considered here. The methane stream has a composition of 92% CH4, 7% O2, and 1% CO2, flowing at a rate of (100+ xy) mol h-¹ where xy are the last two digits of your student ID number. The air stream has a flow rate of 150 mol h-¹. The effluent of the reactor is sent to a flash unit. In this unit, the feed is cooled, resulting in a vapour phase mixture in equilibrium with a liquid phase mixture. The light gases (nitrogen, argon, and oxygen) all end up in the vapour phase. All of the water ends up in the liquid phase. The remaining species are distributed over both phases: 98% of the molar flow rate of methane in the reactor effluent ends up in the vapour phase, along with 87% of the carbon dioxide and 14% of the formaldehyde. The remaining amounts of the methane, carbon dioxide, and formaldehyde are in the liquid phase. The flash unit has two output streams. The first output stream consists of the vapour phase of the two phases that result from cooling the feed to the flash unit. The second output stream comes out of the bottom of the flash unit and consists of the liquid phase. The vapour output stream of the flash vessel is considered a waste product of the whole process. The liquid output stream of the flash vessel is sent to a distillation column which separates the stream into the tops output stream, primarily formaldehyde, and a bottoms product stream which is primarily water. 95% of the formaldehyde fed to this unit ends up in the tops product stream and 95% of the water ends up in the bottoms product stream. The methane and carbon dioxide appear only in the tops product stream. The tops output stream is destined to be the product stream for sale in the formaldehyde market. The bottoms output stream is another waste stream of the process. The following questions must be answered. In answering these questions, show all work, cite all sources of data (including the text book), and make sure to carry units of measure throughout your calculations. The marks (for a total of 100) for each question are indicated in the right margin. 1. Draw and fully label the process diagram. 2. Perform a degree of freedom analysis and demonstrate that you have sufficient information to determine the component flow rates of all streams in the process. 3. Determine the component flow rates of all streams in the process. 4. Assume that the feed streams are fed at ambient conditions (25 °C and 1 bar pressure) as vapour and that the reactor is to operate at 550 °C with the effluent coming out as vapour at this temperature. Use a temperature of 25 °C and pressure of 1 bar as reference conditions for enthalpy calculations to perform the following tasks: i) Determine the inlet-outlet table for the reactor. ii) What are the standard heats of reaction for the two reactions? iii) At what rate should heat be added or removed from the reactor during oper- ation?
Expert Answer:
Answer rating: 100% (QA)
Solutions feed rate of methanol 10 moleshr As per the stoichiometry of the reaction CH3OH05O2 HCHOH2O 1 1 mole of methanol consumed 05 moles of O2 and ... View the full answer
Related Book For
Auditing An International Approach
ISBN: 978-0071051415
6th edition
Authors: Wally J. Smieliauskas, Kathryn Bewley
Posted Date:
Students also viewed these chemical engineering questions
-
Planning is one of the most important management functions in any business. A front office managers first step in planning should involve determine the departments goals. Planning also includes...
-
Sketch a graph to illustrate your idea of each of the following relationships. Be sure to label each axis appropriately. For each relationship, explain under what circumstances, if any, the curve...
-
Each turn of a screw sinks it 3 / 16 of an inch deeper into a piece of wood. Find how deep the screw is after 8 turns. inch 16
-
The potential system in Figure 14.70 is symmetric about the y-axis. Set the initial values at the free nodes equal to zero and calculate the potentials at nodes 1 to 5 for five iterations. 2 4 5 OV...
-
What limits the lifetime of a battery?
-
Of the skills mentioned in the chapter that a project manager needs, which are most important here? Why? MINI CASE Mr. Robert Rutland, founder of the National Jazz Hall of Fame, poured himself...
-
Question four (20mks) Explain how the following are fundamental in appraising income property A. potential gross income (16mks) B.Net operating income (4mks) Question five (20mks) Explain the theory...
-
Suppose that an investor holds a share of Sophia common stock, currently valued at $50. She is concerned that over the next few months the value of her holding might decline, and she would like to...
-
Elise and Philip have respectively $160 and $120 in savings today. Each day, they spend respectively $10 Savings and $5. (S) 4 a) Represent, in the same Cartesian plane, the savings that Elise and...
-
Which option would best help the external auditor evaluate the objectivity of the client's internal auditor? Group of answer choices Evaluate the quality of the internal auditor's documentation...
-
Equipment acquired at the beginning of the year at a cost of $125,000 has an estimated residual value of $5,000 and an estimated useful life of 10 years. Determine the (a) depreciable cost, (b)...
-
With respect to the Hola-Kola case: The Capital Budgeting Decision, why is Net Working Capital not added for every single year 1,2,3,4 as well? Ideally, there should be no WC in Year 0 because the...
-
Kenji is a 34-year-old lawyer who just bought a universal life insurance policy to protect his two children (ages 5 and 6) in the event of his death. Each year, Kenji chooses how much he would like...
-
On January 1 of the current year, Barton Corporation issued 6% bonds with a face value of $76,000. The bonds are sold for $73,720. The bonds pay interest semiannually on June 30 and December 31, and...
-
In each equation, is y directly proportional, Inversely proportional, or not proportional to x? (a) y = 5x directly proportional o inversely proportional o not proportional (b) y= 5x + 6 directly...
-
What did Lennox gain by integrating their WMS, TMS, and labor management systems?
-
You were engaged to examine the financial statements of Kingston Company for the year ended December 31. Assume that on November 1, Kingston borrowed $500,000 from North Country Bank to finance plant...
-
Why is it not necessary to test control weaknesses? What action does the auditor need to take when control evaluation work indicates a control weakness?
-
Is there anything odd about these situations? (1) Auditors performed a surprise payroll distribution, and J. Jones, S. Smith, and D. Douglas were absent from work. (2) A cheque to Larson Lectric...
-
Use subjective judgment to estimate the probability that the next time you ride an elevator, it gets stuck between floors.
-
Because it is impossible for Thanksgiving to fall on Tuesday, the probability of Thanksgiving falling on Tuesday is 0. For Exercises 510, decide whether the statement makes sense (or is clearly true)...
-
What do we mean when we say that the probability of getting 20 babies of the same gender when 20 random babies are born is 1/524,288? Is such an event unusual? Why or why not?
Study smarter with the SolutionInn App