| Date post: | 02-Jun-2018 |
| Category: |
Documents |
| Upload: | shahrizatsmailkassim |
| View: | 212 times |
| Download: | 0 times |
of 9
8/10/2019 CHE450_CHE471_CHE481
1/9
CONFIDENTIAL
EH/OCT 2009/CHE450/471/481
UNIVERSITI TEKNOLOGI M R
FIN L EX MIN TION
COURSE
COURSE CODE
EXAMINATION
TIME
CHEMICAL PROCESS PRINCIPLESI
CHE450/471/481
OCTOBER 2009
3 HOURS
INSTRUCTIONSTOCANDIDATES
1 .
This question paper consistsoffive 5)questions.
2. Answer ALL questionsinthe Answer Booklet. Start each answer ona newpage.
3. Do not bring any material into the examination room unless permission is given by the
invigilator.
4. Please checktomake sure that this exam ination pack consistsof:
) theQuestion Paper
) anAnsw er Booklet- providedby theFaculty
) aone-page A ppendix1
iv) aone-page Appendix2
v) atwo-page A ppendix3
DO NOT TURNT ISP GEUNTILYOU RE TOLD TO O SO
This examination paper consists
of
printed pages
HakCipta Universiti Teknologi M ARA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
2/9
CONFIDENTIAL
2
EH/OCT 2009/CHE450/471/481
QUESTION 1
a) In biological systems, enzym es are used to accelerate the rates of certain biological
reactions. Glucoamylase is an enzyme that aids in the conversion of starch to
glucose (a sugar that cells use for energy). Experiments show that 1 ug-mol of
glucoamylase in a 4% starch solution results in a production rate of glucose of
0.6 ug-mol/mLmin. Determine the production rate of glucose for this system in the
units of lb-m ol/ft
3
day.
(5 marks)
b) A seed crystal of diameter D (mm) is placed in a solution of dissolved salt and new
crystals are observed to nucleate (form) at a constant rate of r (crystals/min).
Experiments with seed crystals of different sizes show that the rate of nucleation, r,
varies with the seed crystal diameter, D, as
r (crystals/min) = 200D - 10D
2
where D is in mm.
i) From the above e quation, determine the units of the constants.
(3 marks)
ii) Calculate the crystals nucleation rate in crystals/s corresponding to a crystal
diameter of 0.05 in.
(5 marks)
iii) Derive a form ula for r' (crystals/s) in term s of D' (in.). Verify the formu la using
the result of part (ii).
(7 marks)
QUESTION 2
Fresh orange juice contains 12.0 wt% solid and the balance water, and concentrated orange
juice contains 42.0 wt%
solid.
Initially a single evaporation process was used for the
concentration, but volatile constituents of the juice escaped with the water, leaving the
concentrate with a flat tastes. The current process overcomes this problem by bypassing the
evaporator with a fraction of the fresh juice. The juice that enters the evaporator is
concentrated to 58 wt% solid and the evaporator product stream is mixed with the bypassed
fresh juice to achieve the de sired final concentration.
a) Draw and label a flowchart of the process.
(5 marks)
Hak Cipta Universiti Teknologi M ARA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
3/9
8/10/2019 CHE450_CHE471_CHE481
4/9
CONFIDENTIAL
4
EH/OCT 2009/CHE450/471/481
QUESTION 4
a) The term gas and vapour are often used interchangeably. Briefly explain the term
gas and vapour.
(5 marks)
b) A tank in a room at 19C is initially open to the atmosphere on a day when the
barometric pressure is 1 02 kPa. A block of dry ice (solid C 0
2
) with a mass of 15.7 kg
is dropped into the tank, which is then sealed. The reading on the tank pressure
gauge initially rises very quickly, then m uch m ore slowly, eventually reaching a value
of 3.27 M Pa. Assumel
fina
is 19C.
i) Calculate the initial mol of air in the tank. Neglect the volume occu pied by C0
2
in
the solid state, and assume that a negligible amount of C0
2
escapes prior to the
sealing of the tank.
(5 marks)
ii) Calculate the final density (g/L) of the gas in the tank.
(5 marks)
iii) Explain what is happe ning in the tank during the initial rapid pressure increase
and during the later slow pressure increase.
(5 marks)
(Gasconstant: R = 8.314 m
3
Pa/molK)
QUESTION 5
a) The total energy of a system has three com ponen ts. Describe these three
components.
(6 marks)
b) A closed system in a process means that no mass is transferred across its
boundaries while the process is taking place. Describe the two ways that energy may
be transferred b etween such a system and its surroundings.
(3 marks)
Hak Cipta Universiti Teknologi MA RA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
5/9
CONFIDENTIAL 5 EH/OCT 2009/CHE450/471/481
c) A 10 m
3
tanks contains steam at 275C and 15.0 bar. The tank and its contents are
cooled until the pressure drops to 1.2 bar. Some of the steam condenses in the
process.
i) Find the final temperatu re of the tank content.
(2 marks)
ii) Calculate the amou nt of steam condensed (kg).
(3 marks)
iii) Calculate the amount of heat transferred from the tank.
(6 marks)
END OF QUESTION PAPER
Hak Cipta Universiti Teknologi MARA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
6/9
CONFIDENTIAL
APPENDIX 1
EH/OCT 2009/CHE450/471/481
TABLE 1 0Factors for unit conversions.
Quantity
Mass
Length
Volume
Force
Pressure
Energy
Power
Equivalent Values
1 kg =1 000 g = 0.001 metric ton = 2.20462 lb
m
= 35.27392oz
1 lb
m
= 1 6 oz = 5X10
4
ton = 453.593 g = 0.453593 kg
1 m = 100 cm = 1 000 mm = 10
6
microns (um) = 10
1 0
angstroms (A)
= 39.37 in = 3.2808 ft =
1.0936
yd = 0.0006214 mile
1 ft = 12 in = 1/3 yd = 0.3048 m = 30.48 cm
1 m
3
= 1000 L = 10
6
cm
3
= 1 0
6
mL
= 35.3145 ft
3
220.83 imperial gallons = 264.17 gal = 1056.68 qt
1 ft
3
= 1 728 in
3
= 7.4805 gal = 0.028317 m
3
= 28.317 L = 28,317 cm
3
1 N = 1 kg.m/s
2
= 10
5
dynes = 1 0
5
g .cm/s
2
= 0.22481 lb
f
1 lb
f
= 32.174 lb
m
.ft/s
2
= 4.4482 N = 4.4482 x 1 0
5
dynes
1 atm = 1.01325x10
5
N/m
2
(Pa) = 101.325 kPa =1.0325bar
=1.01325x 1 0
6
dynes/cm
2
= 760 m mH g at 0C (torr) = 10.333 m H
2
0 at 4C
= 14.696 lb
f
/in
2
(psi) = 33.9 ft H
2
0 at 4C
= 2 9.921 in Hg at 0C
1 J = 1 N.m = 10
7
ergs = 1 0
7
dyne.cm
= 2.778 x 10
7
kW.h = 0.23901 cal
= 0.7376 ft. lb , = 9.486 x 10
4
Btu
1 W = U / s = 0.23901 cal/s = 0.7376 ft . lb
f
/s = 9.486x 10
4
Btu/s
= 1 .341x10 '
3
hp
Hak Cipta Universiti Teknologi MARA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
7/9
CONFIDENTIAL APPENDIX 2 EH/OCT 2009/CHE450/471/481
TABLE 2.0 Properties of Saturated Steam: Pressure Table
/ (bar)
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.2
2,4
2,6
2.8
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
4.6
4.8
5.0
5,5
6.0
6,5
7.0
T(C)
102.3
104.8
107.1
109.3
111.4
113.3
115.2
116.9
H8.6
120.2
123.3
126,1
128.7
131.2
133.5
135.8
137,9
139.9
141.8
143.6
145.4
147.1
148.7
150,3
151.8
155.5
158.8
162.0
165.0
?
8/10/2019 CHE450_CHE471_CHE481
8/9
CONFIDENTIAL
APPENDIX 3(1)
EH/OCT 2009/CHE450/471/481
TABLE3.0PropertiesofSuperheated S team.
>>(bar)
( r t * C )
0.0
-)
0.1
(45.8)
0.5
(81.3)
1.0
(99.6)
5.0
(151.8)
10
(179.9)
20
(212.4)
40
(250.3)
60
(275.6)
80
(295.0)
100
(311.0)
150
(342.1)
200
(365.7)
221.2(/\.)
(374.15X7-,:)
t
0
9
t
0
V
t
0
9
t
0
9
t
0
1/
t
0
9
t
0
t
0
9
t
0
P
t
0
9
t
0
V
t
0
t
0
9
t
0
V
Sat'd
W a t e r
191.8
191.8
0.00101
340.6
340.6
0.00103
417.5
417.5
0.00104
640.1
639.6
0.00109
762.6
761.5
0.00113
908.6
906.2
0.00118
1087.4
1082.4
0.00125
1213.7
1205.8
0.00132
1317.1
1306.0
0.00139
1408.0
1393.5
0.00145
1611.0
1586.1
0.00166
1826.5
1785.7
0.00204
2108
2037.8
0.00317
Sat'd
S t e a m
2584.8
2438.0
14.7
2646.0
2484.0
3.24
2675.4
2506.1
1.69
2747.5
2560.2
0.375
2776.2
2582
0.194
2797.2
2598.2
0.09950
2800.3
2601.3
0.04975
2785.0
2590.4
0.0325
2759.9
2571.7
0.0235
2727.7
2547.3
0.0181
2615.0
2459.9
0.0103
2418.4
2300.8
0.005875
2108
2037.8
0.00317
Temperature
50
2595
2446
2593
2444
14.8
209.3
209.2
0.00101
209.3
209.2
0.00101
209.7
209.2
0.00101
210.1
209.1
0.00101
211.0
209.0
0.00101
212.7
208.6
0.00101
214.4
208.3
0.00101
216.1
208.1
0.00101
217.8
207.8
0.00101
222.1
207.0
0.00101
226.4
206.3
0.00100
228.2
206.0
0.00100
( C ) -
75
2642
2481
2640
2 4 8 0
16.0
313.9
313.9
0.00103
314.0
313.9
0.00103
314.3
313.8
0.001O3
314.7
313.7
0.00103
315.5
313.5
0.00102
317.1
313.0
0.00102
318.7
312.6
0.00103
320.3
312.3
0.00102
322.9
311.7
0.00102
326.0
310.7
0.00102
330.0
309.7
0.00102
331.7
309.2
0.00102
100
2689
2 5 1 7
2688
2516
17.2
2683
2512
3.41
2676
2 5 0 7
1.69
419.4
418.8
0.00104
419.7
418.7
0.00104
420.5
418.4
0.00104
422.0
417.8
0.00104
423.5
417.3
0.00104
425.0
416.7
0.00104
426.5
416.1
0.00104
430.3
414.7
0.00104
434.0
413.2
0.00103
435.7
412.8
0.00103
150
2784
2589
2783
2588
19.5
2780
2586
3.89
2776
2583
1.94
632.2
631.6
0.00109
632.5
631.4
0.00109
633.1
603.9
0.00109
634.3
630.0
0.00109
635.6
629.1
0.00109
636.8
628.2
0.00109
638.1
627.3
0.00109
641.3
625.0
0.00108
644.5
622.9
0.00108
645.8
622.0
0.00108
200
2880
2662
2880
2661
21.8
2878
2660
4.35
2875
2658
2.17
2855
2643
0.425
2827
2621
0.206
852.6
850.2
0.00116
853.4
848.8
0.00115
854.2
847.3
0.00115
855.1
845.9
0.00115
855.9
844.4
0.00115
858.1
841.0
0.00114
860.4
837.7
0.00114
861.4
836.3
0.00114
250
2978
2736
2977
2736
24.2
2979
2735
4.83
2975
2734
2.40
2961
2724
0.474
2943
2710
0.233
2902
2679
0.111
1085.8
1080.8
0.00125
1085.8
1078.3
0.00125
1085.8
1075.8
0.00124
1085.8
1073.4
0.00124
1086.2
1067.7
0.00123
1086.7
1062.2
0.00122
1087.0
1060.0
0.00122
300
3077
2812
3077
2812
26.5
3076
2811
5.29
3074
2811
2.64
3065
2803
0.522
3052
2794
0.258
3025
2774
0.125
2962
2727
0.0588
2885
2 6 6 8
0.0361
2787
2593
0.0243
1343.4
1329.4
0.00140
1338.2
1317.6
0.00138
1334.3
1307.1
0.00136
1332.8
1302.9
0.00135
350
3177
2890
3177
2890
28.7
3177
2889
5.75
3176
2889
2.87
3168
2883
0.571
3159
2876
0.282
3139
2862
0.139
3095
2829
0.0665
3046
2792
0.0422
2 9 9 0
2 7 5 0
0.0299
2926
2702
0.0224
2695
2523
0.0115
1647.1
1613.7
0.00167
1635.5
1600.3
0.00163
250
-)
300
(-)
500
-)
1000
(-)
ft
ft
ft
ft
v
230.7
205.7
0.00100
235.0
205.0
0.0009990
251.9
202.4
0.0009911
293.9
196.5
0.0009737
334.0
308.7
0.00101
338.1
307.7
0.00101
354.2
304.0
0.00100
394.3
295.7
0.0009852
437.8
412.1
0.00103
441.6
410.8
0.00103
456.8
405.8
0.00102
495.1
395.1
0.001000
647.7
620.8
0.00108
650.9
618.7
0.00107
664.1
611.0
0.00106
698.0
594.4
0.00104
862.8
834.4
0.00113
865.2
831.3
0.00113
875.4
819.7
0.00111
903.5
795.3
0.00108
1087.5
1057.0
0.00122
1088.4
1052.1
0.00121
1093.6
1034.3
0.00119
1113.0
999.0
0.00114
1331.1
1297.5
0.00135
1328.7
1288.7
0.00133
1323.7
1259.3
0.00129
1328.7
1207.1
0.00122
1625.0
1585.0
0.00160
1609.9
1563.3
0.00155
1576.3
1504.1
0.00144
1550.5
1419.0
0.00131
Hak Cipta Universiti Teknologi MARA
CONFIDENTIAL
8/10/2019 CHE450_CHE471_CHE481
9/9
CONFIDENTIAL APPENDIX 3 (2) EH/OCT 2009/CHE450/471 /481
TA BL E 4.0 Propert ies of Superheated Steam (Continued).
/ (bar)
T
M
X)
0.0
(-)
0.1
(45.8)
0.5
(81.3)
1.0
(99.6)
5.0
(151.8)
10
(179.9)
2 0
(212.4)
4 0
(250.3)
6 0
(275.6)
80
(295.0)
100
(311.0)
150
(342.1)
200
(365.7)
22\.2 P
C
)
(374.15)(r
c
)
250
(-)
300
(-)
500
(-)
1000
(-)
ft
0
ft
0
V
ft
0
i
0
ft
0
ft
0
V
ft
0
ft
0
1?
ft
0
ft
0
9
ft
0
9
ft
0
ft
0
9
ft
0
V
ft
0
ft
0
1?
ft
0
1?
ft
u
9
Temperature (C)
4 00
4 5 0
3280
2969
3280
2969
21.1
3279
2969
6.21
3278
2968
3.11
3272
2964
0.617
3264
2958
0.307
3249
2946
0.151
3216
2922
0.0734
3180
2896
0.0474
3142
2867
0.0344
3100
2836
0.0264
2975
2744
0.0157
2820
2622
0.009950
2733
2553
0.008157
2582
2432
0.006013
2162
2077
0.002830
1878
1791
0.001726
1798
1653
0.001446
3384
3050
3384
3050
33.3
3383
3049
6.67
3382
3049
3.33
3379
3045
0.664
3371
3041
0.330
3358
3031
0.163
3331
3011
0.0799
3303
2991
0.0521
3274
2969
0.0382
3244
2946
0.0298
3160
2883
0.0185
3064
2810
0.0127
3020
2776
0.0110
2954
2725
0.009174
2826
2623
0.006734
2293
2169
0.002491
2051
1888
0.001628
500
3497
3132
3489
3132
35.7
3489
3132
7.14
3488
3132
3.57
3484
3128
0.711
3478
3124
0.353
3467
3115
0.175
3445
3100
0.0864
3422
3083
0.0566
3399
3065
0.0417
3375
3047
0.0328
3311
2999
0.0208
3241
2946
0.0148
3210
2922
0.0130
3166
2888
0.0111
3085
2825
0.008680
2723
2529
0.003882
2316
2127
0.001893
550
3597
3217
3596
3217
38.0
3596
3216
7.58
3596
3216
3.80
3592
3213
0.758
3587
3210
0.377
3578
3202
0.188
3559
3188
0.0926
3539
3174
0.0609
3520
3159
0.0450
3500
3144
0.0356
3448
3105
0.0229
3394
3063
0.0166
3370
3045
0.0147
3337
3019
0.0127
3277
2972
0.0102
3021
2765
0.005112
2594
2369
0.002246
600
3706
3303
3706
3303
40.3
3705
3302
8.06
3705
3302
4.03
3702
3300
0.804
3697
3296
0.402
3689
3290
0.200
3673
3278
0.0987
3657
3265
0.0652
3640
3252
0.0483
3623
3240
0.0383
3580
3207
0.0249
3536
3172
0.0182
3516
3157
0.0162
3490
3137
0.0141
3443
3100
0.0114
3248
2946
0.006112
2857
2591
0.002668
650
3816
3390
3816
3390
42.6
3816
3390
8.55
3816
3390
4.26
3813
3388
0.850
3809
3385
0.424
3802
3379
0.211
3788
3368
0.105
3774
3357
0.0693
3759
3346
0.0515
3745
3335
0.0410
3708
3307
0.0267
3671
3278
0.197
3655
3265
0.0176
3633
3248
0.0143
3595
3218
0.0126
3439
3091
0.007000
3105
2795
0.003106
700
3929
3480
3929
3480
44.8
3929
3480
9.01
3928
3479
4.48
3926
3477
0.897
3923
3475
0.448
3916
3470
0.223
3904
3460
0.111
3892
3451
0.0735
3879
3441
0.0547
3867
3431
0.0435
3835
3407
0.0286
3804
3382
0.211
3790
3371
0.0190
3772
3356
0.0166
3740
3330
0.0136
3610
3224
0.007722
3324
2971
0.003536
750
4043
3591
4043
3571
47.2
4043
3571
9.43
4042
3570
4.72
4040
3569
0.943
4038
3567
0.472
4032
3562
0.235
4021
3554
0.117
4011
3545
0.0776
4000
3537
0.0578
3989
3528
0.0461
3962
3507
0.0304
3935
3485
0.0225
3923
3476
0.0202
3908
3463
0.0178
3880
3441
0.0147
3771
3350
0.008418
3526
3131
0.003953
Hak Cipta Universiti Teknologi M ARA
CONFIDENTIAL
