
The fresh feed to an ammonia production process contains nitrogen and hydrogen in stoichiometric proportion, along with an inert gas (I). The feed is combined with a recycle stream containing the same three species, and the combined stream is fed to a reactor in which a low single-pass conversion of nitrogen is achieved. The reactor effluent flows to a condenser. A liquid stream containing essentially all of the ammonia formed in the reactor and a gas stream containing all the inerts and the unreacted nitrogen and hydrogen leave the condenser. The gas stream is split into two fractions with the same composition: one is removed from the process as a purge stream, and the other is the recycle stream combined w ith the fresh feed. In every stream containing nitrogen and hydrogen, the two species are in stoichiometric proportion.
RecyclePurge
Fresh feedN,. Hj. 1 | Nj,H2 | ||||
REACTOR | CONDENSER | CondensateMl. | |||
- Let .¥io be the mole fraction of inerts in the fresh feed, /sp the single-pass conversion of nitrogen (and of hydrogen) in the reactor, and y the fraction of the gas leaving the condenser that is purged (mol purged/mol total). Taking a basis of 1 mol fresh feed, draw and fully label a process flowchart, incorporating .tio,/sp, and yp in the labeling to the greatest possible extent. Then, assuming that the values of these three variables are given, write a set of equations for the total moles led to the reactor (nr), moles of ammonia produced (np), and overall nitrogen conversion (fm). Each equation should involve only one unknown variable, which should be circled.
- Solve the equations of Part (a) for .vw = 0.01,= 0.20. and yp = 0.10.
- Briefly explain in your ow n words the reasons for including (i) the recycle stream and (ii) the purge stream in the process design.
xio | fsp | yp | nr | np | fov |
0.01 | 0.20 | 0.10 | |||
0.05 | 0.20 | 0.10 | |||
0.10 | 0.20 | 0.10 | |||
0.01 | 0.30 | 0.10 |
Summarize the effects on ammonia production (/tp) and reactor throughput (nr) of changing each of the three input variables.

Want to see the full answer?
Check out a sample textbook solution
Chapter 4 Solutions
Elementary Principles of Chemical Processes, Binder Ready Version
Additional Engineering Textbook Solutions
Modern Database Management
Starting Out With Visual Basic (8th Edition)
Java How to Program, Early Objects (11th Edition) (Deitel: How to Program)
Starting Out with Java: From Control Structures through Objects (7th Edition) (What's New in Computer Science)
Degarmo's Materials And Processes In Manufacturing
Database Concepts (8th Edition)
- Can you provide me the answer of these pleasearrow_forwardA constant-volume process involving 2.0 moles of diatomic ideal gas, for which cV = (5/2)R, is at an initial state of 111 kPa and 277 K and is then heated reversibly to 356 K. Calculate the P2 (kPa), dU (kJ), heat transfer q (kJ mol–1), and w (kJ mol–1).arrow_forwardProblem 1 Marks: 60 Section: 1a): 30 marks, Section 1b):30 marks A laboratory scale fluidized bed is considered for studying a catalytic ozone decomposition. a) It is requested to derive model equations under the following assumptions: ■ Operation of the catalytic reactor under steady state conditions, There is no influence of thermal ozone decomposition reactions. The fluidized bed includes bubbles and dense phase. □ The dense phase can be simulated using a CSTR The fluidized bed bubbles contain catalyst particles and can be simulated as a DSTR (batch). □ The jets contain particles and can be simulated with a PFR. The influence of the freeboard has to be considered using a PFR model. The available catalytic reaction rate model is r (moles/gcat.s)= -k CA b) Same than on a) under unsteady state conditions, using an absorbable and reactive tracer. Note: A step-by step derivation of the model equations is required here. A quick answer will not do. Problem 2 Marks: 40 Section 2a: 30 marks,…arrow_forward
- Penicillin process Penicillium chrysogenum is used to produce penicillin in a 90,000-litre fermenter. The volumetric rate of oxygen uptake by the cells ranges from 0.45 to 0.85 mmol l^−1 min^−1 depending on time during the culture. Power input by stirring is 2.9 W l^−1. Estimate the cooling requirements.arrow_forwardProduction of bakers’ yeast Bakers’ yeast is produced in a 50,000-litre fermenter under aerobic conditions. The carbon substrate is sucrose; ammonia is provided as the nitrogen source. The average biomass composition is CH_1.83O_0.55N_0.17 with 5% ash. Under conditions supporting efficient growth, biomass is the only major product and the biomass yield from sucrose is 0.5 g g^−1. If the specific growth rate is 0.45 h^−1, estimate the rate of heat removal required to maintain constant temperature in the fermenter when the yeast concentration is 10 g l^−1.arrow_forwardSensible energy change Calculate the enthalpy change associated with the following processes:(a) m-Cresol is heated from 25°C to 100°C(b) Ethylene glycol is cooled from 20°C to 10°C(c) Succinic acid is heated from 15°C to 120°C(d) Air is cooled from 150°C to 65°Carrow_forward
- ▼ Enzyme conversion An immobilised enzyme process is used in an ice-cream factory to hydrolyse lactose (C12H22O11) to glucose (C6H12O6) and galactose (C6H1206): C12H22O11 + H2O →→ C6H12O + C6H12O6 Gel beads containing ß-galactosidase are packed into a column reactor; 2500 kg of lactose enters the reactor per day as a 10% solution in water at 25°C. The reactor operates at steady state and 32°C; all of the lactose is converted. Because the heat of reaction for enzyme conversions is not as great as for cell culture, sensible heat changes and heats of mixing cannot be ignored. Lactose Water Ah (kJ gmol¹) C, (cal g¹ ºC-¹) Ahm (kcal gmol¹) 3.7 -5652.5 0.30 1.0 Glucose -2805.0 0.30 5.6 Galactose -2805.7 0.30 5.6 (a) What is the standard heat of reaction for this enzyme conversion? (b) Estimate the heating or cooling requirements for this process. State explicitly whether heating or cooling is needed.arrow_forwardBacterial production of alginate Azotobacter vinelandii is investigated for production of alginate from sucrose. In a continuous fermenter at 28°C with ammonia as nitrogen source, the yield of alginate was found to be 4 g g^−1 oxygen consumed. It is planned to produce alginate at a rate of 5 kg h^−1. Since the viscosity of alginate in aqueous solution is considerable, energy input due to mixing the broth cannot be neglected. The fermenter is equipped with a flat-blade disc turbine; at a satisfactory mixing speed and air flow rate, the power requirements are estimated at 1.5 kW. Calculate the cooling requirements.arrow_forwardPreheating nutrient medium Steam is used to heat nutrient medium in a continuous-flow process. Saturated steam at 150°C enters a coil on the outside of the heating vessel and is completely condensed. Liquid medium enters the vessel at 15°C and leaves at 44°C. Heat losses from the jacket to the surroundings are estimated as 0.22 kW. If the flow rate of medium is 3250 kg h^−1 and its heat capacity is 0.9 cal g^−1 °C^−1, how much steam is required?arrow_forward
- Q3] Determine the optimal operating conditions (XA, t, and CR) in a mixed flow reactor to maximize the concentration of R (CR) in the effluent, where an aqueous feed A with an initial concentration of CA0-40 mol/m³ enters the reactor, undergoes decomposition, and exits as a mixture containing A, R, and S. K₁ AR, FR = k₁C, k₁ = 0.4 m³/(mol min) SA AS, rs = k₂CA, k₂ = 2(min), CA0 = 40 mol/m³arrow_forwardConsider the parallel decomposition of A of different orders with FR = 1, rs = 2CA and IT = C. Determine the maximum concentration of desired product obtainable in mixed flow reactor and plug flow reactor. (1) R is desired product and CA0 = 2. (2) S is desired product and CA0 = 4. R S Tarrow_forward1. Copper is known to be toxic to fish, and in particular, the free ion Cu²+ species typically shows greatest toxicity. a. Calculate the speciation of Cu(II) for freshwater at a pH value of 8.3 as the hardness increases from 20 (soft) to 100 (moderately hard) to 200 (very hard) mg/L as CaCO3. Assume that the total divalent Cu(II) concentration is 10 µg/L. b. Based on your findings in part (a), do you think it is appropriate to set a single regulatory limit or should it depend on variables such as pH and hardness? Explain your answer.arrow_forward
- Introduction to Chemical Engineering Thermodynami...Chemical EngineeringISBN:9781259696527Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark SwihartPublisher:McGraw-Hill EducationElementary Principles of Chemical Processes, Bind...Chemical EngineeringISBN:9781118431221Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. BullardPublisher:WILEYElements of Chemical Reaction Engineering (5th Ed...Chemical EngineeringISBN:9780133887518Author:H. Scott FoglerPublisher:Prentice Hall
- Industrial Plastics: Theory and ApplicationsChemical EngineeringISBN:9781285061238Author:Lokensgard, ErikPublisher:Delmar Cengage LearningUnit Operations of Chemical EngineeringChemical EngineeringISBN:9780072848236Author:Warren McCabe, Julian C. Smith, Peter HarriottPublisher:McGraw-Hill Companies, The





