Questions and Answers of Chemical Engineering Design

Design a vertical shell and tube condenser for the duty given in question 12.7. Use the same preferred tube size.Data from 12.7A condenser is required to condense n-propanol vapor leaving the top of
The reactor described in Example 12.15 is fitted with a flat blade disc turbine agitator 0.6 m diameter, running at 120rpm.The vessel is baffled and is constructed of stainless-steel plate 10 mm
A jacketed, agitated reactor consists of a vertical cylinder 1.5 m diameter, with a hemispherical base and a flat, flanged, top. The jacket is fitted to the cylindrical section only and extends to a
Investigate the use of an air-cooled exchanger for the duty set out in Example 12.1. Determine the fan power consumption.Data from example 12.1Design an exchanger to sub-cool condensate from a
Investigate the use of a gasketed plate heat exchanger for the duty set out in Example 12.1: cooling methanol using brackish water as the coolant. Titanium plates are to be specified, to resist
Design a vaporizer to vaporize 5000kg/h n-butane at 5.84 bar. The minimum temperature of the feed (winter conditions) will be 0°C. Steam is available at 1.70 bar (10 psig). 90 145 H Tube O.D 30 mm D
Make a preliminary design for a vertical thermosyphon reboiler for a debutanizer column that has the bottoms composition given below. Take the vapour rate required to be 36kmol/h.Bottoms composition:
Make a preliminary design for a vertical thermosyphon for a column distilling crude aniline. The column will operate at atmospheric pressure and a vaporization rate of 6000 kg/h is required. Steam is
A fluid whose properties are essentially those of o-dichlorobenzene is vaporized in the tubes of a forced convection reboiler. Estimate the local heat-transfer coefficient at a point where 5 per cent
Design a condenser for the following duty: 45,000kg/h of mixed light hydrocarbon vapours to be condensed. The condenser to operate at 10 bar. The vapour will enter the condenser saturated at 60°C
It is proposed to use an existing distillation column, which is fitted with a dephlegmator (reflux condenser) that has 200 vertical, 50 mm i.d., tubes, for separating benzene from a mixture of
Estimate the heat-transfer coefficient for the pool boiling of water at 2.1 bar, from a surface at 125°C. Check that the critical flux is not exceeded.
Estimate the heat-transfer coefficient for steam condensing on the outside, and on the inside, of a 25 mm o.d., 21 mm i.d. vertical tube 3.66 m long. The steam condensate rate is 0.015 kg/s per tube
Optimize the design of Example 12.3 using commercial heat exchanger design software.Data from example 12.3Design a shell-and-tube exchanger for the following duty. 20,000kg/h of kerosene (42° API)
Design a shell-and-tube exchanger for the following duty. 20,000kg/h of kerosene (42° API) leaves the base of a kerosene side-stripping column at 200°C and is to be cooled to 90°C by exchange with
Gas oil at 200°C is to be cooled to 40°C. The oil flow-rate is 22,500kg/h. Cooling water is available at 30°C and the temperature rise is to be limited to 20°C. The pressure drop allowance for
Design an exchanger to sub-cool condensate from a methanol condenser from 95°C to 40°C. The flow-rate of methanol is 100,000kg/h. Brackish water will be used as the coolant, with a temperature rise
Acetone is to be extracted from a solution in water, using 1,1,2-trichloroethane. The feed concentration is 45.0 per cent w/w acetone. Determine the number of stages required to reduce the
Sulphur dioxide produced by the combustion of sulphur in air is absorbed in water. Pure SO2 is then recovered from the solution by steam stripping. Make a preliminary design for the absorption
Calculate the plate efficiency for the plate design considered in Examples 11.6 and 11.7, using Van Winkle’s correlation.Data from example 11.6 Design the plates for the column specified in
For the plate design in Example 11.6, estimate the plate efficiency for the plate on which the concentration of acetone is 5 mol per cent. Use the AIChE method.Data from Example 11.6Design the plates
Design the plates for the column specified in Example 11.2. Take the minimum feed rate as 70 per cent of the maximum (maximum feed 10,000 kg/h). Use sieve plates.Data from example 11.2Acetone is to
Using O’Connell’s correlation, estimate the overall column efficiency and the number of real stages required for the separation given in Example 11.3, when the reflux ratio is 2.0.Data from
Estimate the position of the feed point for the separation considered in Example 11.3, for a reflux ratio of 3.Data from Example 11.3Estimate the minimum number of ideal stages needed in the
Estimate the minimum number of ideal stages needed in the butane-pentane splitter defined by the compositions given in the table below. The column will operate at a pressure of 8.3 bar. Evaluate the
Acetone is to be recovered from an aqueous waste stream by continuous distillation. The feed contains 10 mol% acetone. Acetone of at least 95 mol% purity is wanted, and the aqueous effluent must not
A feed to a column has the composition given in the table below and is at a pressure of 14 bar and a temperature of 60 °C. Calculate the flow and composition of the liquid and vapour phases. Take
Design a cyclone to recover solids from a process gas stream. The anticipated particle size distribution in the inlet gas is given below. The density of the particles is 2500 kg/m3, and the gas is
Design a decanter to separate a light oil from water. The oil is the dispersed phase. Oil, flow rate 1000 kg/h, density 900 kg/m3, viscosity 3mN s/m2. Water, flow rate 5000 kg/h, density 1000 kg/m3,
A reverse osmosis plant is to be designed to produce 50 kg/s of boiler feed water with less than 20 ppmw of NaCl starting from sea water that contains 3.5 wt% NaCl. The 40 m2 membrane modules operate
Estimate the size of hydro cyclone needed to separate 90 per cent of particles with a diameter greater than 20 μm, from 10 m3/h of a dilute slurry. Physical properties: solid density 2000 kg/m3,
Yang et al. (1997) gives isotherm data for adsorption of methane on zeolite 5A in the presence of hydrogen:It has been determined that a four-bed PSA plant using this adsorbent can be used to purify
A distillation column separates benzene from toluene using a control scheme similar to that shown in Figure 5.26c. Make a practice HAZOP study of the plant section and add any instrumentation that is
Evaluate the Dow F & EI for the nitric acid plant illustrated in Chapter 4, Figure 4.2.Data from figure 4.2 Flows kg/h Pressures nominal Line no. Stream Component NH3 0 N NO NO HNO3 HO Total Press
Using Lydersen’s method, estimate the critical constants for isobutanol. Compare your values with those given in Appendix C.Data from appendix c NO 1 2 3 4 5 Formula AR BCL3 BF3 BR2 CLNO CL2 CL3P
For the compounds listed below, estimate the constants in the equation for ideal gas heat capacity, equation 3.19, using the method given in Section 8.9.2.1. 3-methyl thiophene.2. Nitrobenzene.3.
Make a rough estimate of the viscosity of 2-butanol and aniline at their boiling points, using the modified Arrhenius equation. Compare your values with those given using the equation for viscosity
Estimate the diffusivity of phenol in ethanol at 20 °C (293 K).
Estimate the diffusivity of methanol in air at atmospheric pressure and 25 °C.
Estimate the latent heat of vaporization of acetic anhydride, C4H6O3, at its boiling point, 139.6 °C (412.7 K), and at 200 °C (473 K).
Estimate the specific heat capacity of isopropyl alcohol at 500 K.
Estimate the specific heat capacity of chlorobutadiene at 20 °C, using Chueh and Swanson’s method.
Using Chueh and Swanson’s method, estimate the specific heat capacity of ethyl bromide at 20 °C.
Estimate the specific heat capacity of urea, CH4N2O.
Estimate the thermal conductivity of ethane at 1 bar and 450 °C.
Estimate the thermal conductivity of benzene at 30 °C.
Estimate the viscosity of toluene at 80 °C, using the value at 20 °C given in Example 8.2.Data from Example 8.2Estimate the viscosity of toluene at 20 °C.
Estimate the viscosity of toluene at 20 °C.
Calculate the density of a mixture of methanol and water at 20 °C, composition 40 per cent w/w methanol. Density of water at 20C Density of methanol at 20 C 998.2 kg/m 791.2 kg/m
The pipeline described in question 7.1 was used to carry wastewater to a hold-up tank.The effluent is not hazardous. A decision has to be made on what material to use to replacethe pipe. Three
Carry out a sensitivity analysis of the adipic acid project described in Examples 6.11 and 6.12.Data from example 6.11Adipic acid is used in the manufacture of nylon 6,6. It is made by hydrogenation
A preliminary (Class 4) estimate of the ISBL capital cost of building a 200,000 ton per year ethanol plant by corn dry milling has been stated as $130 MM -30% / +50%. The plant is to be built on a
A plant is producing 10,000 metric tons per year (10 kMTA) of a product. The overall yield is 70 per cent, on a mass basis (kg of product per kg raw material). The raw material costs $500/metric ton,
The adipic acid plant in Example 6.11 is built with 30% of the fixed investment in year 1 and 70% in year 2, and the plant operates at 50% of capacity in year 3 before reaching full capacity in year
Adipic acid is used in the manufacture of nylon 6,6. It is made by hydrogenation of phenol to a mixture of cyclohexanol and cyclohexanone (known as KA oil – ketone and alcohol), followed by
A carbon steel heat exchanger that costs €140,000 is expected to have a service life of five years before it requires replacement. If type 304 stainless steel is used then the service life will be
A chemical plant with a fixed capital investment of $100 million generates an annual gross profit of $50 million. Calculate the depreciation charge, taxes paid and after-tax cash flows for the first
The light naphtha isomerization process is more complex than the description given in Example 4.7. 1. Hydrogen is flowed through the plant to reduce catalyst deactivation. The hydrogen flow rate is
The autothermal reforming of methane to hydrogen was described in Example 4.2. The solution in the example was not optimized, and suggestions were given for how to improve the results. Optimize the
Methyl ethyl ketone (MEK) is manufactured by the dehydrogenation of 2-butanol. A simplified description of the process listing the various units used is given below: 1. A reactor in which the
The batch fermentation of glucose to glutamic acid using Brevibacterium divaricatum is described in detail in US patent 2,978,384. In Example I in the patent a 10.5 wt% glucose feed was fermented for
Light naphtha is a mixture produced by distillation of crude oil. Light naphtha primarily contains alkane compounds (paraffins) and it can be blended into gasoline. The octane value of
Continuing the problem defined in Example 4.3, use a rigorous simulation to carry out tray sizing and estimate the required column diameter.Data from example 4.3This example provides more detail on
In an ethanol plant, the mixture of water and ethanol from the beer column distillate contains about 40% ethanol (molar basis) in water, together with the fusel oils described in the previous
This example provides more detail on the solution of the problem that was introduced as Example 1.1. The original problem statement was to optimize the design of a distillation column to separate 225
Hydrogen can be made by steam reforming of methane, which is a highly endothermic process: Steam reforming is usually carried out in fired tubular reactors, with catalyst packed inside the tubes and
When heavy oils are cracked in a catalytic or thermal cracking process, lighter hydrocarbon compounds are formed. Most cracking processes on heavy oil feeds form products with carbon numbers ranging
If the gases leave the tower at 6 atm, 25°C, and are expanded to, say, 1.5 atm, calculate the turbine exit gas temperatures without preheat, and if the gases are preheated to 400°C with the reactor
Methane is compressed from 1 bar and 290 K to 10 bar. If the isentropic efficiency is 0.85, calculate the energy required to compress 10,000 kg/h. Estimate the exit gas temperature.
Calculate the standard heat of reaction for the following reaction: the hydrogenation of benzene to cyclohexane. (1) C6H6(g) + 3H₂(g) → C6H12(g) (2) C6H6(g) + 7 O₂(g) 6CO₂(g) + 3H₂O(1)
Illustrates the manual calculation of a reactor heat balance.Vinyl chloride (VC) is manufactured by the pyrolysis of 1,2-dichloroethane (DCE). The reaction is endothermic. The flow-rates to produce
Estimate the specific enthalpy of ethyl alcohol at 1 bar and 200 °C, taking the datum temperature as 0°C.Cp liquid 0°C 24.65 cal/mol°C100°C 37.96 cal/mol°C Boiling point of ethyl alcohol at 1
An alternative process for converting benzene to cyclohexane also uses a supported noble metal catalyst, but carries out the reaction in the liquid phase, at a temperature of 160 °C and pressure of
Estimate the annual cost of providing refrigeration to a condenser with duty 1.2 MW operating at – 5°C. The refrigeration cycle rejects heat to cooling water that is available at 40 °C, and has
Estimate the NPV at a 12% interest rate and the DCFROR for the project described in Example 6.8, using the MACRS depreciation method.Data in example 6.8A chemical plant with a fixed capital
A new process is being developed for converting benzene to cyclohexane by hydrogenation over a noble metal catalyst. The reaction is carried out at 50 bara, at a feed temperature of 220 °C, and the
A gasoline surge drum has capacity 4 m3 (1060 gal) and is normally operated 50% full at 40°C (100°F) under 20 bar absolute pressure (280 psig) of hydrogen in the head space and using a level
Laboratory test data for a trip system shows a failure rate of 0.2 per year. If the demand rate is once every two years and the test interval is six months, what is the hazard rate? Should a parallel
This example illustrates how the techniques used in an operability study can be used to decide the instrumentation required for safe operation. Figure 9.6a shows the basic instrumentation and control
Estimate the surface tension of pure methanol at 20 °C, density 791.7 kg/m3, molecular weight 32.04.
Estimate the critical constants for diphenylmethane using Lydersen’s method; normal boiling point 537.5 K, molecular mass 168.2, structural formula:
A precipitate is to be continuously separated from a slurry. The solids concentration is 5 per cent and the slurry feed rate5.5 m3/h. The relevant physical properties at the system operating
Make a preliminary design for a separator to separate a mixture of steam and water; flow-rates: steam 2000 kg/h, water 1000 kg/h; operating pressure 4 bar.
Design a horizontal separator to separate 10,000 kg/h of liquid, density 962.0 kg/m3, from 12,500 kg/h of vapor, density 23.6 kg/m3. The vessel operating pressure will be 21 bar.
Complete a failure mode effect analysis for the nitric acid plant reactor section described in Example 9.2. (This is best carried out as a group activity with a group size of three to six).Data from
Devise a preliminary control scheme for the sections of the nitric acid plant described in Chapter 4, flow-sheet Figure 4.2, which are listed below. Make a practice HAZOP study of each section and
Develop a fault tree for events that could lead to release of benzene to the atmosphere for the distillation section designed in problem 9.5.Data from problem 9.5A distillation column separates
Estimate the Dow Fire and Explosion Index, and determine the hazard rating, for the processes listed below. Use the process descriptions given in Appendix F and develop the designs, as needed, to
It has been suggested that carbon dioxide can be recovered from flue as using a membrane process. The flue gas has composition: nitrogen 73.9 mol%, oxygen 3.1 mol%, carbon dioxide 7.7 mol%, water
An electronics plant uses an adsorption system to recover solvent from a vent gas stream and prevent volatile organic compound (VOC) emissions. The vent gas flow rate is 20 m3/s of dry air at 293 K,
In the production of aniline by the hydrogenation of nitrobenzene, the reactor products are separated from unreacted hydrogen in a condenser. The condensate, which is mainly water and aniline,
The product from a crystallizer is to be separated from the liquor using a centrifuge. The concentration of the crystals is 6.5 per cent and the slurry feed rate to the centrifuge will be 5.0 m3/h.
At a pressure of 10 bar, determine the bubble and dew point of a mixture of hydrocarbons, composition, mol per cent: n-butane 21, n-pentane 48, n-hexane 31. The equilibrium K factors can be estimated
The feed to a distillation column has the following composition, mol per cent: propane 5.0, isobutane 15, n-butane 25, isopentane 20, n-pentane 35. The feed is preheated to a temperature of 90 °C,
In the manufacture of methyl ethyl ketone (MEK). The product MEK is extracted from a solution in water using 1,1,2 trichloroethane as the solvent.For a feed rate 2000 kg/h of solution, composition 30
A column is required to recover acetone from an aqueous solution. The feed contains 5 mol per cent acetone. A product purity of 99.5 per cent w/w is required and the effluent water must contain less
The heat duty of the jacketed vessel of Examples 12.15 and 12.16 can be estimated from the coolant flow rate and temperatures. What is the minimum temperature at which the reactor can operate using
In the manufacture of methyl ethyl ketone (MEK) from 2-butanol, the reactor products are precooled and then partially condensed in a shell and tube exchanger. A typical analysis of the stream
A stirred tank fermentation reactor has height 2 m, diameter 1.5 m and is filled with a fermentation broth that can be assumed to have the physical properties of water. The fermenter must be
A storage tank is purged continuously with a stream of nitrogen. The purge stream leaving the tank is saturated with the product stored in the tank. A major part of the product lost in the purge

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