Chemical Engineering Answers

If 45 m3 of combustion products at 1000 K of the following

composition: 6.2 % O2, 1.0% H2O, 12.3 % CO2, and the balance N2 are cooled at atmospheric pressure from 1000 K to 250 K, what is

the enthalpy change in the J?

Calculate the enthalpy change that occurs when 5 lb of CO2 change

state from 8 psia and a mixture containing 20 % liquid plus solid to

200 oF by a constant volume process.

A 15 MW steam-driven turbine operates in the steady-state using 30

kg/s of steam. The inlet condition for the steam is p = 3000 kPa and

450 oC. The outlet condition is 500 kPa, saturated vapor. The

entering velocity of the steam is 250 m/s and the exiting velocity is

40 m/s. What is the transfer in kW for the turbine as the system?

What fraction is the heat transfer of the power generated?

Consider the autocatalytic reaction A --+ R, with -rA = 0.001 CACR moll

1iter.s. We wish to process 1.5 litersls of a CAo = 10 mollliter feed to the

highest conversion possible in the reactor system consisting of four 100-

liter mixed flow reactors connected as you wish and any feed arrangement.

Sketch your recommended design and feed arrangement and determine

CAf from this system

200 kg/min of feed are fed to a continuous distillation column. The stream contains 70 kg /min NaOH and the difference is water. The distillate flows out of the column at 90 kg /min and contains 4 kg /min NaOH. Determine the bottom stream mass flowrate and the composition of all streams. Draw and label the flowchart.

Use Raoult's Law and calculate the vapour and liquid compositions in equilibrium (in mole fractions, y and x) for the A-B components system using vapour pressure data measured at a pressure of 101.32 kPa as shown in Table 1 below. Draw the Temperature composition diagrams the Equilibrium distribution (x-y) plot as well.

Table 1: vapour pressure data measure

Temperature

60

78

86

92

96

101

Vapour pressure

Component A

101.325

132

156

178

195

235

Component B

0

58

68

78

88

101.325

Methanol (M) is to be separated from water (W) by atmospheric distillation. The feed contains 22 kg/hr methanol and 25 kg/hr water. The distillate contains 90 mol% methanol and the bottom product contains 5 mol% of methanol. The feed is saturated.

(a) Calculate the molar flow rates of methanol and water in the bottom and distillate product stream.

(b) Determine the minimum number of stages and minimum reflux for the problem. If the equilibrium data is given as;

x 0.032 0.0523 0.075 0.154 0.225 0.349 0.813 0.918 1

y 0.19 0.2494 0.352 0.516 0.593 0.703 0.918 0.953 1

Methanol (M) is to be separated from water (W) by atmospheric distillation. The feed contains 22 kg/hr methanol and 25 kg/hr water. The distillate contains 90 mol% methanol and the bottom product contains 5 mol% of methanol. The feed is saturated. Calculate the molar flow rates of methanol and water in the bottom and distillate product stream.

200 kg/min of feed are fed to a continuous distillation column. The stream contains

70 kg /min NaOH and the difference is water. The distillate flows out of the column at

90 kg /min and contains 4 kg /min NaOH. Determine the bottom stream mass flow

rate and the composition of all streams. Draw and label the flowchart.

A packed counter-current water cooling tower is used to cool

1.356 kg/s.m2

of water from 43.3 °C to 26.7 ºC. The air enters from the bottom

of the tower at 23.9 ºC with a wet bulb temperature of 21.1 ºC. The whole of the

resistance to heat and mass transfer can be considered as being within the gas

phase and the product of the mass transfer coefficient and the transfer surface

per unit volume of column (KG.a) may be taken as 1.207×10-7

kmol/s.m3

.Pa.

The tower operates at atmospheric pressure. Calculate the minimum air flowrate

and the necessary height of the tower when 1.5 times of minimum is used as

actual air flowrate.

Data: Latent heat of water at 0 ºC = 2501 kJ/ kg

Heat capacity of dry air = 1.005 kJ/ kg. ºC

Heat capacity of water vapour = 1.88 kJ/ kg. ºC

Density of air = 1.198 kg/ m3

Enthalpy of saturated air-water vapour data are as follows:

Hyi, kJ/kg dry air 84 97.2 112.1 128.9 148.2 172.1 197.2

Temperature, ºC 26.7 29.4 32.2 35 37.8 40.6 43.3