ABSTRACTBiochemical processes is one of the process occurred in the living things’ cells. Generally there are many processes in the biochemical process and of it is the aerobic diffusion as in the bioreactor stirred tank experiment. The main objective of this experiment is to identify the mass transfer coefficient for each parameter being investigated, such as the effect of the agitation speed, the aeration rate as well as the temperature of the solution into the bioreactor stirred tank. The agitation speed effect can be identified by fixing the aeration rate being supplied into the reactor to be 2 L/min and the fixed temperature is 30˚C. The agitation speed effect can be started at the 200 rpm of speed and the nitrogen can be supplied into the bioreactor so that the oxygen concentration can be reduced until it is saturated. Only after that, the flow is stopped and the oxygen can be supplied again at the fixed constant as mention before. The value of the concentration contained in the reaction is measured by recording the pO2 reading at the panel and this value is the C L value that will be used to plot the graph by using (Equation 1) mentioned in the Theory section. Finally, the steps are repeated for different agitation speed of 400 rpm, 600 rpm, 800 rpm and 1000rpm. The overall step also can be used in determining the effect of the aeration rate but with the different fixed variable, which is by using the agitation speed of 400 rpm and the temperature of 30˚C. The aeration rate can be varies from 0.5 L/min, 1.0 L/min, 1.5 L/min and 2.5 L/min. Not only that, the overall step also can be used in determining the effect of the temperature but with the different fixed variable, which is by using the agitation speed of 400 rpm and the aeration rate of 2 L/min. The temperature can be varies from 30˚C, 35˚C, 40˚C, 45˚C and 50˚C. From the graph of ln (C*-CL) against time plotted, the equation for each line can be measured since the slope of the line is the kLa value for that parameter. From the results, it shown that the higher agitation speed of the impeller gives the highest the value of the mass transfer coefficient, kLa. Besides, the highest aeration rate being supplied into the bioreactor tank also gives the highest value of the mass transfer coefficient, kLa. Finally, the highest temperature of a reaction also gives the highest value mass transfer coefficient compared to the lower temperature. INTRODUCTION There are many biochemical reactions existed in this life since this reaction is much more efficient rather than another reaction. Biochemical reactions are one of the chemical reactions that take place in living things’ cells. The reactions that happened in an organism are called as metabolism and this is including both exothermic as well as the endothermic reactions (Foundation, 2017). Generally, there are few types of biochemical reactions such as oxidation and reduction, movement of functional groups within or between molecules, addition and removal of water and also the bond-breaking reactions (CliffNotes, 2016). Mostly, these reactions require some amount of oxygen in order for it to operate efficiently and to produce the product of the reaction. In order to achieve the aim, the dissolved oxygen concentration becoming the most needed variable to be supplied into the biochemical reaction continuously. This is because it is to ensure that the oxygen supplied is maintained throughout the experiment while the organism is consuming the oxygen. Physically, the oxygen is purged into the bioreactor and transferring the air bubbles into the solution. After that, it will breaking up and mixed well in the solution by the stirrer. For this experiment, there parameters is used to determine the difference in the mass transfer coefficient, kLa value which is the effect of agitation speed, aeration rate and also the temperature. The importance of studying the mass transfer coefficient shows that the effective transfer process is by ensuring the mass transfer rate of oxygen to the liquid must equal or exceeding the rate at which the cells take up the oxygen. This proved that the process conditions must adequate sufficient amount of oxygen for the cell to consume freely as it will grow (Kane, 2012). Basically, aerobic reaction is using the following formula to utilize graphical method: dCL/dt = Oxygen Transfer Rate (OTR) – Oxygen Uptake Rate (OUR) dCL/dt = kLa (C* - CL) – qO2 . X OBJECTIVES 1. To investigate the effect of agitation speed on volumetric oxygen transfer rate 𝐾𝐿 𝐴 , in a stirred tank bioreactor. 2. To investigate the effect of aeration rate on volumetric oxygen transfer rate 𝐾𝐿 𝐴 , in a stirred tank bioreactor. 3. To investigate the effect of the temperature on volumetric oxygen transfer rate 𝐾𝐿 𝐴 , in a stirred tank bioreactor. THEORY The main objective of running this experiment is absolutely to find the mass transfer coefficient, kLa for each parameter, which is agitation speed, aeration rate and also the temperature. Firstly, a graph is plotted between ln (C* - CL) which shows how much is the amount of oxygen gas contained in that certain reaction at certain period of time. The y-axis value for the first graph is: y-axis = ln (C* - CL) (Equation 1) this values will be plotted against time recorded for each parameter until it reaches 100% of pO2, or at least it reached its constant value of pO2 which showed that it has already reaching its ‘100% value’. After the graph is drawn, the equation for each line is measured to identify the slope for each line. y = mx + c, where the m is = kLa (Equation 2) From the equation, the mass transfer coefficient, kLa can be directly calculated from the line’s slope and the value is converted into the unit of h-1. Then, these values for each line is plotted to show the relation between the different in parameter with their respected value of mass transfer coefficient. Calibration meter . No. Aeration meter 3. Descriptions 1.APPARATUS 1 2 3 4 Figure 1: Bioreactor stirred tank. Reader for pO2 4. Bioreactor vessel 2. 𝑂2 to the bioreactor is supplied at flow rate of 2. 3. The agitation of bioreactor is set to 200rpm. 2.5 L/min and 2. Steps 2 to 4 is repeated for different agitation speed (400rpm. Steps 2 to 4 is repeated for different temperature (35˚C. 600rpm.5L/min. 𝐶𝐿 value is obtained at constant time interval during aeration 5. 6.0 L/min until saturated then the flow is stopped. Oxygen concentration of the solution is lowered by gassing the liquid out with 𝑁2 at 9 L/min until saturate and the flow is stopped. 1. 2.PROCEDURE LAB 1: The effect of agitation speed study. Oxygen concentration of the solution is lowered by gassing the liquid out with 𝑁2 at 9 L/min until saturate and the flow is stopped. 1. . The aeration of the bioreactor is set to 0. The temperature of the bioreactor is set to 30˚C. 4. LAB 3: The effect of temperature study. 1. 40˚C. 4. 45˚C and 50˚C). LAB 2: The effect of aeration rate study. 𝐶𝐿 value is obtained at constant time interval of 5 seconds during aeration. 1.5 L/min). 5. 6. Oxygen concentration of the solution is lowered by gassing the liquid out with 𝑁2 at 9 L/min until saturate and stop the flow. 800 rpm and 1000rpm). 𝑂2 to the bioreactor is supplied to the bioreactor at fixed agitation rate of 400 rpm and at temperature of 30˚C until saturated and the flow is stopped. 3. The 𝐾𝐿 𝐴 value of stirred tank reactor is calculated at different aeration rate. 5. 6. 2. Steps 2 to 4 is repeated for different aeration rate (1 L/min. The 𝐾𝐿 𝐴 value of stirred tank reactor is calculated at different agitation speed. 𝑂2 to the bioreactor is supplied to the bioreactor at fixed agitation rate of 400 rpm and at aeration rate at 2 L/min until saturated and the flow is stopped. The 𝐾𝐿 𝐴 value of stirred tank reactor is calculated at different temperature. 𝐶𝐿 value is obtained at constant time interval of 5 seconds during aeration. 3. 4. The effect of agitation speed with constant of the temperature (30˚C) and the aeration rate (2L/min).70 0 1.40 92.00 94.80 75.00 60 46.50 40 31.60 50.80 66.40 100.70 98.87 5.48 3.40 20 15.70 45 35.00 0.50 84.80 95.70 10 9.80 25.10 99.70 65. Table 1: The reading measured from the experiment for agitation speed effect.40 15 11.20 86.90 25 19.00 43.40 26.06 4.20 84.40 94.00 70 53.10 53. Time Agitation speed (rpm) (s) 200 400 600 800 1000 0.80 55 42.00 76.80 77.60 57.40 95 66.70 32.60 98.30 100 .90 70.60 80.90 38.80 85 61.50 99.91 13.70 41.00 10.90 72.00 97.32 8.09 2.70 81.80 75 55.40 83.90 97.00 89.90 73.80 64.00 90 63.03 14.40 97.70 16.80 56.20 69.80 50.90 19.40 69.80 79.20 30 23.10 88.00 65 49.00 1.20 93.20 91.90 96.90 45.RESULTS A.80 55.80 79.72 5 4.00 50 39.30 23.30 83.30 35 27.30 99.50 91.00 99.30 32.60 98.80 29.40 41.00 0.50 87.00 0.50 60.70 88.10 100.00 80 58.90 85.60 95. 30 155 85.10 130 79.90 115 74.90 95.00 120 76.00 180 90.60 99.90 190 91.50 99.00 225 95.70 91.40 98.20 145 83.90 135 80.90 97.70 175 89.60 140 81.40 95.60 90.30 94.50 93.70 96.50 98.40 230 .10 97.40 170 88.80 99.50 99.20 185 90.90 105 70.70 89.10 125 77.20 98.90 205 93.60 195 92.60 220 95. 68.40 99.20 200 92.50 210 94.00 100.00 215 94.20 100.80 150 84.10 165 87.60 160 86.50 110 72. 80 235 96.60 280 98.90 320 100.40 305 99.70 245 97.90 290 99.10 270 98.30 240 96.60 310 99.30 255 97.40 275 98. 95.80 315 99.00 325 .60 260 97.30 300 99.10 295 99.00 250 97.70 285 98.90 265 98. 28 3.61 4.87 -0.CL) ln (C* .80 45 4.17 2.51 2.03 2.38 0.33 4.57 4.72 2.91 3.65 60 4.12 40 4.61 90 3.05 3.CL) ln (C* .10 .49 15 4.90 3.22 4.52 4.39 4.55 4.08 55 4.48 4.38 2.79 3.16 3.42 50 4.58 1.30 3.61 80 3.85 3.39 4.33 4.50 4.21 3.91 1.65 0.22 3.30 4. Time ln (C* .79 3.89 3.56 4.44 4.46 0.99 3.43 2.59 -1.31 20 4.13 0.52 0.58 10 4.59 2.28 - 95 3.78 1.07 25 4.00 75 3.77 2.Table 2: The value calculated to plot the graph of ln (C*-CL) for agitation speed (rpm) against time.30 2.55 2.03 4.56 3.44 2.79 1.CL) ln (C* .45 4.76 30 4.10 3.43 4.08 3.77 1.61 4.52 35 4.11 - 85 3.53 -1.25 4.03 1.12 3.65 2.97 2.83 3.61 4.19 2.46 4.59 4.96 100 3.10 0.36 1.10 65 3.99 3.41 3.15 1.CL) (s) at 200 rpm at 400 rpm at 600 rpm at 800 rpm at 1000 rpm 4.61 4.45 2.53 105 3.56 4.67 2.CL) ln (C* .74 3.69 70 3.59 0 5 4. 90 1.41 140 2.05 205 1.69 115 3.38 2.59 135 3.22 145 2.10 -2.21 195 2.61 230 1.67 0.110 3.25 -0.13 200 2.83 0.75 0.95 - 125 3.96 1.20 180 2.53 -0.79 155 2.79 220 1.87 215 1.77 130 3.11 170 2.10 1.96 210 1.03 150 2.31 2.03 1.24 1.28 190 2.53 .34 165 2.51 175 2.30 120 3.38 - 185 2.69 225 1.60 -0.53 160 2.17 1.45 -1. 31 245 1.19 250 1.11 300 -0.88 265 0.51 310 -0.74 270 0.26 290 0.10 255 0.64 275 0.92 315 -1.34 285 0.61 320 -2.10 295 -0.36 305 -0.235 1.30 325 - .47 280 0.99 260 0.44 240 1. 00 0. Agitation speed (rpm) kLa value (h-1) 200 61.0478x + 5. (s) ln (C* . rpm effect against time.56 400 105.00 time. s.00 y = -0.00 ln (C* .0171x + 5.0292x + 5. (rpm) against 6.CL) of agitation speed.3261 (1000 rpm) -3.00 y = -0.1526 (400 rpm) y = -1.12 600 172.CL) @ 600 rpm 3.00 ln (C* .00 ln (C* .CL) @ 200 rpm ln (C* . Table 3: The calculated value of kLa (h-1) for agitation speed effect given from the previous graph.00 time (s) Figure 2: The graph of ln (C* .CL) for agitation speed (rpm) 5.00 ln (C* .20 1000 259.CL) @ 400 rpm 4.2738 (600 rpm) -2.20 .00 y = -0.CL) @ 1000 rpm 1. ln (C*-CL) for agitation speed.08 800 223.CL) @ 800 rpm 2.062x + 5.1407 (200rpm) 0 50 100 150 200 250 300 350 -0.2101 (800 rpm) y = -0.072x + 5. 00 0. kLa value for agitation speed effect 300.00 150. .00 250.00 kLa value (h-1) 200.00 0 200 400 600 800 1000 1200 Agitation speed (rpm) Figure 3: The kLa value (h-1) for each of the agitation speed value.00 kLa value for 100.00 agitation speed effect 50. 60 50 17.70 -1.80 75 35.90 10 -1.60 71.70 62.30 25.40 85 40.60 32.53 15.20 20.5 L/min 5 -1.80 53.10 31.30 55 21.10 59.20 55.80 58.38 11.60 53.60 90 43.22 25 0.20 3.20 15 -1. Time (s) Aeration rate (L/min) 0.20 35.80 13.57 1.89 9.00 42.90 59.40 -1.20 45.20 38.80 -1.30 46.60 25.58 0.5 L/min 2.48 20 -1.70 0.10 34.70 69.40 60 25.40 4.40 65 29. Table 4: The reading measured from the experiment for aeration rate effect.29 6.40 41.80 70 32.70 95 46.00 29.40 35 6.70 62.40 64.16 12.70 -1.20 50.80 28.80 52.80 66.90 105 51.00 39.80 49.10 58.50 42.5 L/min 1.40 19.40 -1.65 7. B.90 66.40 36.70 45 14.90 51.0 L/min 1.40 55.50 100 48. The effect of aeration rate with constant of the agitation speed (400 rpm) and the temperature (30˚C).70 48.80 46.30 .70 68.00 30 3.90 18.70 80 38.30 24.00 56.00 64.80 40 10.30 -1.20 60. 40 83.70 68.00 80.10 82.80 115 55.10 140 64.20 63.00 82.110 53.90 120 57.90 72.30 150 67.20 71.50 80.30 71.80 80.80 75.10 68.90 215 80.80 81.30 76.40 73.10 170 72.80 145 65.20 78.40 76.40 75.60 74.10 75.60 79.30 74.30 78.00 185 75.60 80.50 82.60 .20 79.60 78.80 210 80.60 130 61.90 66.40 81.00 83.30 65.60 205 79.10 61.20 81.70 81.30 81.40 77.70 83.50 77.10 83.90 82.70 83.90 72.70 81.70 73.60 77.30 76.00 79.80 125 58.10 82.70 74.40 230 82.20 195 77.40 81.70 69.70 165 71.90 81.30 135 62.30 77.80 80.20 160 69.80 80.80 81.80 180 74.10 190 76.20 79.90 83.90 80.20 225 82.10 81.70 69.30 78.30 72.10 82.30 78.40 200 78.00 81.50 82.20 82.10 81.20 73.50 83.00 220 81.40 175 73.80 82.50 79.80 77.80 155 68. 20 86.80 87.60 345 91.00 85.60 300 89.50 86.00 87.70 85.60 355 92.80 87.70 88.50 87.20 270 86.90 82.00 85.00 88.10 87.90 83.00 260 86.80 83.80 315 90.70 84.60 85.90 250 85.50 84.235 83.60 83.80 84.50 88.50 85.80 86.10 265 86.70 88.20 330 90.40 86.80 85.00 85.50 83.10 86.00 84.70 83.60 83.70 86.50 87.30 85.80 245 84.70 86.60 85.70 350 91.30 88.30 82.10 83.00 255 85.50 83.00 83.70 310 89.10 325 90.70 240 84.80 86.30 335 91.60 84.30 83.70 305 89.70 .60 86.00 85.40 290 88.10 88.40 88.50 295 88.10 84.40 340 91.50 83.40 83.30 280 87.30 87.40 84.00 84.40 86.20 275 87.30 285 88.00 82.80 83.10 83.50 84.20 86.20 84.00 84.50 85.20 86.10 320 90. 70 89.40 89.70 89.60 89.40 89.360 92.80 365 92.20 88.80 89.70 465 94.40 89.20 89.50 88.40 420 93.60 .60 445 94.90 380 92.30 410 93.60 450 94.40 88.70 460 94.50 435 94.70 470 94.00 385 92.00 89.20 400 93.80 370 92.10 89.50 430 93.90 375 92.40 425 93.70 455 94.10 89.70 89.00 89.20 89.30 89.50 480 94.40 89.70 475 94.30 415 93.60 440 94.40 89.20 395 93.20 405 93.60 89.30 88.00 89.10 390 92. 90 525 94.80 505 94.80 515 94.60 490 94.80 510 94.20 570 95.20 .10 540 95.20 560 95.90 520 94.00 535 95.90 530 95.70 500 94.70 495 94.20 565 95.485 94.10 550 95.10 545 95.20 555 95. 36 4.86 50 4.39 3.41 4.40 4.48 4.12 3.03 3.CL) ln (C* .84 3.33 2.5 L/min at 1.19 4.18 2.92 3.60 3.86 3.65 105 3.46 3.43 3.08 85 3.15 3.45 10 4.44 4.48 4.73 3.99 3.07 40 4.31 75 4.96 45 4.12 3.51 4.78 3.96 3.57 4.57 4.89 3.CL) ln (C* .25 3.41 70 4.74 3.09 2.99 3.5 L/min at 2.69 3.91 2.19 3.52 3.63 60 4.28 30 4.19 80 4.46 4.86 95 3.97 90 3.79 3.35 4.60 3.65 3.48 4.39 4.45 15 4.41 20 4.05 3.0 L/min at 1.55 4.75 100 3.46 4.25 2.55 110 3.00 2.19 35 4.31 4.94 3.09 3.Table 5: The value calculated to plot the graph of ln (C*-CL) for aeration rate (L/min) against time.57 4.34 2.21 4.36 25 4.55 65 4.05 3.35 4.57 4.76 55 4.30 4.52 4.49 4.29 4.CL) Time (s) at 0. ln (C* .24 4.87 3.42 .CL) ln (C* .51 4.78 3.53 3.5 L/min 5 4. 67 155 3.76 1.79 215 2.28 2.04 1.83 210 2.71 2.10 1.62 1.39 170 3.16 0.25 1.59 0.115 3.13 185 2.47 1.13 2.10 190 2.41 1.19 2.23 2.06 195 2.63 3.03 1.39 0.03 0.19 1.99 200 2.42 1.17 2.74 220 2.76 2.91 2.34 .53 1.66 2.35 1.83 2.66 1.69 3.86 2.41 235 2.25 0.87 2.19 180 3.90 1.34 1.07 2.84 145 3.72 1.47 1.60 2.53 230 2.67 1.59 2.00 2.13 2.05 135 3.73 2.26 2.53 3.67 2.76 150 3.92 205 2.31 0.06 2.76 1.15 1.33 2.95 1.38 2.14 130 3.39 0.16 1.03 2.64 225 2.43 2.48 3.57 1.59 3.23 125 3.06 0.10 1.53 1.73 2.31 175 3.48 165 3.59 160 3.80 2.27 1.83 2.48 1.95 140 3.82 1.93 1.77 1.32 120 3.72 1.98 2.53 0.92 2. 42 1.41 0.79 0.88 0.26 -2.64 -0.92 335 1.11 .11 270 2.01 1.20 315 1.10 -0.95 1.36 - 320 1.88 0.16 0.79 0.99 0.41 -0.90 0.240 2.10 355 1.65 0.51 295 1.64 -0.26 -1.20 340 1.59 0.00 360 1.39 0.53 -0.74 -0.41 0.92 305 1.22 1.16 0.13 1.32 1.10 -0.86 0.36 0.99 0.22 285 1.00 265 2.22 280 2.65 0.18 -0.10 0.15 1.34 -0.99 0.79 0.53 0.47 -0.18 250 2.69 0.50 0.59 0.36 290 1.92 310 1.69 300 1.55 0.11 275 2.51 325 1.25 0.10 260 2.10 -0.11 -1.34 0.25 0.26 1.69 0.31 0.81 0.69 -0.08 1.06 0.74 0.10 255 2.18 - 350 1.59 -0.26 245 2.30 345 1.69 330 1.47 -0.37 1.26 -0. 51 485 -0.30 440 0.06 -0.69 -0.22 380 0.41 -1.99 -0.18 -2.88 -0.69 400 0.30 450 0.36 480 -0.22 - 475 -0.47 -1.96 -0.92 415 0.92 -0.61 430 0.00 - 460 -0.41 -1.69 395 0.10 -2.30 445 0.69 405 0.61 435 0.36 385 0.92 410 0.59 -0.03 -0.64 -0.20 425 0.79 -0.20 420 0.51 390 0.22 - 470 -0.59 -1.10 - 455 0.365 1.18 -2.22 375 0.22 - 465 -0.11 370 1.51 . 92 515 -1.92 505 -0.30 550 - 555 - 560 - 565 - 570 - .30 540 -2.30 545 -2.61 535 -2.92 510 -0.20 520 -1.69 495 -0.20 525 -1.20 530 -1.69 500 -0.490 -0. 00 3. Table 6: The calculated value of kLa (h-1) for aeration rate effect given from the previous graph.50 64.5 L/min ) -2.5 L/min ) Figure 4: The graph of ln (C* .0162x + 4.5 L/min ) time (s) y = -0.00 51.7422 ( 1.00 ln (C*-CL) for aeration rate (L/min) 4.00 ln (C*-CL) @ 2.5 L/min 0.0 L/min ) -3.0142x + 4.00 ln (C*-CL) @ 1.00 y = -0.44 .50 58. L/min effect against time.5 L/min 0 100 200 300 400 500 600 -1.0179x + 4.00 y = -0. Aeration rate (L/min) kLa value (h-1) 0.CL) of aeration rate.5323 ( 2.12 1. (L/min) against time.04 1.00 ln (C*-CL) @ 1.32 2.0114x + 5.00 ln (C*-CL) @ 0.0528 ( 0.00 y = -0.0 L/min 1.5 L/min 2. ln (C*-CL) for aeration rate. (s) 6.00 5. s.50 41.9189 ( 1. 00 2.00 1.00 kLa value of the aeration rate 20.00 kLa value (h-1) 40. kLa value of the aeration rate effect 70.50 1.00 0.50 2. .00 0.00 60.00 effect 10.00 Aeration rate (L/min) Figure 5: The kLa value (h-1) for each of the aeration rate value.00 30.00 0.50 3.00 50. 50 70 92.50 40 82.30 70.90 65 91.40 98.00 97.50 100 97.60 15 65.80 96.30 77.20 84.40 58.10 92.80 77.30 93.30 90.90 2. Temperature (˚C) Time (s) 30˚C 35˚C 40˚C 45˚C 50˚C 45.50 85.50 52.60 90 96.00 90.60 64. .00 11.50 11.70 24.97 8.40 15.10 31.00 31.20 80 94.90 85 95.70 61.20 96.80 55.80 0.70 50 86.90 68.50 72.90 99.80 95.70 .10 73.70 93.40 95.00 -0.90 91.20 9.50 55 88.00 75 93.50 52.60 31.40 100.50 43.00 95 96.30 62.46 10 61.70 19.80 93.00 105 .20 46.50 86.00 30 77.80 20 69.50 81.30 69.50 46.90 77.30 63.70 28.20 81.10 47.90 88. C.00 87.30 55.80 37.50 100.30 60 89. - 0 50. The effect of temperature with constant value of the agitation speed (400 rpm) and the aeration rate (2 L/min).70 98.20 45 84.70 75.10 40.40 84.90 13.50 17.80 35 79.90 89.30 39.77 2.40 79.40 84.10 5 55.60 88.20 100.00 17.80 25 73.90 68. Table 7: The reading measured from the experiment for the temperature effect.50 24.90 7.00 94. 00 145 Table 8: The value calculated to plot the graph of ln (C*-CL) for temperature (˚C) against time.33 4.60 3.41 4.23 4.57 3.80 3.58 4.85 40 3.30 120 99.00 135 99.96 4.CL) ln (C* .66 4.98 3.00 125 99.30 3.11 3.87 3.30 97.46 3.CL) ln (C* .CL) ln (C* .98 3.86 3.80 3.00 99.10 .28 4.50 4.58 15 3.04 35 3.52 4.80 96.73 3.52 20 3.79 4.01 4.41 4.28 4.33 4.62 45 2.02 3.90 4.41 4.54 4.CL) Time (s) at 30˚C at 35˚C at 40˚C at 45˚C at 50˚C 4.43 4.50 115 98.13 3. ln (C* .08 4.61 4.46 4. 97.44 3.61 10 3.30 99.70 98.64 3.50 100.48 4.CL) ln (C* .23 4.72 3.39 50 2.22 30 3.48 0 5 3.30 110 98.70 130 99.80 140 100.14 4.38 25 3. 69 - 140 -1.53 125 0.31 115 0.17 2.68 2.19 0.96 1.00 0.69 105 0.14 - 80 1.10 3.42 1.36 -1.81 -0.48 0.69 2.32 3.47 - 100 1.77 2.57 1.28 2.94 2.55 2.13 90 1.55 2.22 1.20 135 -0.34 95 1.57 - 110 0.75 1.21 2.00 2.49 2.76 85 1.36 2.42 3.92 120 0.16 1.92 75 2.79 1.59 1.53 0.21 2.37 65 2.62 3.03 2.48 3.92 3.95 1.81 70 2.74 60 2.61 145 - .00 130 -0.11 2.26 0.03 0.87 2. CL) for temperature (˚C) 4.00 60.00 140.00 y = -0.00 120.76 40 164.00 ln (C* .CL) @ T = 45 3.1725 ( T = 35˚C) 0.00 1.00 20. Temperature (˚C) kLa value (h-1) 30 124.CL) @ T = 30 5.3622 ( T = 45˚C) -2. (˚C) against 6. ln (C*-CL) for temperature.00 y = -0.00 y = -0. (s) ln (C* .CL) @ T = 50 2.04 .00 time (s) y = -0. Table 9: The calculated value of kLa (h-1) for temperature effect given from the previous graph.00 ln (C* .0449x + 5.00 time.2 35 131.00 100. ˚C effect against time.1123 ( T = 50˚C) Figure 6: The graph of ln (C* .00 80. s.16 45 161.0366x + 5.CL) @ T = 35 ln (C* .CL) of temperature.3614 ( T = 30˚C ) 0.00 ln (C* .0514x + 5.0456x + 5.CL) @ T = 40 ln (C* .274 ( T = 40˚C) y = -0.64 50 185.00 -1.00 40.00 160.0345x + 4. 00 180.574 The value of 4.00 120.00 kLa value for temperature (h-1) 160.00 140.00 effect 40.0114x + 5. CL = -1.0114 .00 40.00 10.CL) against time.0528 Thus.00 20. y = -0. the slope. kLa value of the temperature effect 200. m for the reaction is = -0.CL) = 4.7)] ln (C* . for aeration rate effect on the bioreactor experiment: For 0.5 L/min of aeration rate.574 is then drawn into a graph against time for each time until it reaches its maximum value as shown in the Figure 3 above. From the graph plotted of the ln (C* .00 30.2 at 550 s.00 0.00 kLa value of the 80.2 – (-1.00 0. the equation of the best fit for each rate was calculated as below: Since y = mx + c So.00 Temperature (˚C) Figure 7: The kLa value (h-1) for each of the temperature value. SAMPLE CALLCULATION In experiment 2. The C* = 95.7 at 5 s The y-axis value is calculated by (Equation 1) as in the theory section: ln (C* .00 60.CL) = ln [95.00 temperature 60.00 50.00 20.00 100. as shown below: kLa (at 0.From the theory section for (Equation 2). The value of 41. The explanation of the graph will be discussed in the Discussion section. the value is converted into h-1 unit first.04 h-1. . it is understood that the slope of the graph is equal to the kLa value of that parameter at that condition. kLa value for the 0.5 L/min) = 41.5 L/min of the aeration rate effect is = 0. Before plotting the graph.04 h-1 is then plotted against the each of the aeration rate experimented as shown in the Figure 4.0114 s-1 x 60 s x 60 min kLa (at 0.0114 s-1. The second graph is plotted based on the kLa value measured before against each parameter as shown in the Figure 4.5 L/min) = 0. Hence. the higher the values of the mass transfer coefficient. It took only 80 s to achieve that value. it clearly shown that the 1000 rpm reaction gave the steeper line compared to another speed due to the time taken for it achieving 100% much faster than another. 600 rpm about 172. The 1000 rpm reaction efficiently breaking down the air bubbles since it has higher sectional area.56 h-1. Then. thus lowering the value of the transfer coefficient (Karimi. 400 rpm took about 180 s and finally the 200 rpm reaction took about 325 s to reach 100%. 2013).2 h-1. For the first experiment which is the effect of the difference reading of the agitation speed in rpm. Next is the effect of the aeration rate on the mass transfer coefficient of a reaction.072.2 h-1 for the mass transfer coefficient value. and 200 rpm about 61. the slope is taken as the value of the coefficient and converted it in the unit of per hour (h-1). For that reason. the difference between the maximum concentration. The negative sign indicate that the graph has negative slope and does not effect on the real value of the mass transfer coefficient. while 800 rpm about 223. the mass transfer coefficient for this reaction is much higher than another speed while the lower speed does not have enough traps to hold up the air bubbles and make the superficial area of the bubbles decreasing. To that aim. The 1000 rpm reaction gave about 259. it is generally concluded that the higher the values of the parameters. bubble retention time and the mixing of the solution. 400 rpm about 105. while 800 rpm reaction took about 90 s.5 L/min reactions gives the faster reaction to reached 100% value of . This is due to the agitation speed affect the problems on the bubble size. the higher the values of the mass transfer coefficient. 600 rpm and 800 rpm.DISCUSSIONS Based on the results tabulated and plotted above.08 h-1. it is generally concluded that the higher the values of the parameters. 600 rpm took about 120 s. kLa. Then. The graph plotted in the Figure 3 proved that the higher the agitation speed in rpm. the higher the mass transfer coefficient. it showed that the agitation speed of 1000 rpm reactions gives the faster reaction to reached 100% value of pO2 reading compared to 200 rpm. From Figure 2.12 h-1. 400 rpm. From the value recorded for every 5 seconds. It showed that the aeration rate of 2. C* and the value of each concentration for each time is calculated thus measuring the value of the ln (C*-CL) to plot the first graph. Based on the results tabulated and plotted above. it will affecting the superficial area of the bubbles than enhanced the transfer rate of the oxygen. k La. the slope of that line much higher than another which is – 0. It took only 75 s to achieve that value.5 L/min reaction gave about 64. C* and the value of each concentration for each time is calculated thus measuring the value of the ln (C*-CL) to plot the first graph.0 L/min and 1.0 L/min about 51. From the value recorded for every 5 seconds.32 h-1. while 45˚C reaction took about 95 s. For that reason.5 L/min reaction gave the steeper line compared to another speed due to the time taken for it achieving 100% much faster than another.0179. the higher the mass transfer coefficient. it clearly shown that the 50˚C reaction gave the steeper line compared to another speed due to the time taken for it achieving 100% much faster than another. it is generally concluded that the higher the values of the parameters.pO2 reading compared to 0.0514. the slope of that line much higher than another which is – 0. The 2. 35˚C took about 135 s and 30˚C took about 145 s to reach 100%. the slope of that line much higher than another which is – 0. 1. The graph plotted in the Figure 5 proved that the higher the aeration rates in L/min. For that reason. 40˚C took about 105 s. 1.44 h-1 of the mass transfer coefficient value meanwhile 1. This increasing mass transfer area is the major reason for the transfer rate being increased as the aeration supplied increased in L/min (Painmanakul. k La. From the value recorded for every 5 seconds.5 L/min reaction took about 345 s. the higher the values of the mass transfer coefficient. The negative sign indicate that the graph has negative slope and does not effect on the real value of the mass transfer coefficient. It showed that the temperature of 50˚C reactions gives the faster reaction to reached 100% value of pO2 reading compared to 30˚C. 1. The negative .04 h-1.5 L/min.5 L/min about 41. 35˚C. Lastly is the effect of the temperature on the mass transfer coefficient of a reaction. This is due to the aeration reaction will produced small bubbles with uniform size of distribution and will lead to the increasing of the mass transfer area between the gas and the liquid solution. while 1.5 L/min about 58. C* and the value of each concentration for each time is calculated thus measuring the value of the ln (C*-CL) to plot the first graph. the difference between the maximum concentration. 40˚C and 45˚C. From Figure 4. Based on the results tabulated and plotted above. the slope is taken as the value of the coefficient and converted it in the unit of per hour (h-1).0 L/min took about 470 s and 0. 2009).5 L/min. It took only 315 s to achieve that value. the difference between the maximum concentration. it clearly shown that the 2.12 h-1 and 0. From Figure 6.5 L/min took about 550 s to reach 100%. Then. 20 h-1. .January 2018).sign indicate that the graph has negative slope and does not effect on the real value of the mass transfer coefficient. the mass transfer driving force. September 2017 . The 50˚C reaction gave about 185.16 h-1.04 h-1 of the mass transfer coefficient value meanwhile 45˚C about 161. 35˚C about 131. This is due to the higher temperature caused the concentration of the dissolved oxygen to be reduced. Then.64 h-1. After all. the slope is taken as the value of the coefficient and converted it in the unit of per hour (h-1). The graph plotted in the Figure 7 proved that the higher the temperature in ˚C. Thus.76 h-1 and 30˚C about 124. This can be best explained by understanding that higher temperature lead to the increasing of the air bubbles and increasing in the diffusivity of the oxygen in the liquid film. the mass transfer coefficient also being increased (Ahmad. the higher the mass transfer coefficient. which is (C*-CL) also being decreasing. 40˚C about 164. from Types of Biochemical Reactions: https://www. C. cK-12. highest aeration rate being supplied into the reactor as well as the highest temperature being supplied through the temperature probe. J. Retrieved December. However. from Types of Biochemical Reactions: https://www. Same goes with the aeration rate effect on the transfer coefficient. Lastly. from Measuring kLa for Better Bioreactor Performance: . (September 2017 . the higher the value of the mass transfer coefficient.-1. BioProcess International. Retrieved December. RECOMMENDATIONS REFERENCES Ahmad. N. Retrieved December. 2017. there is slightly little error in this temperature experiment. The higher the aeration rate supplied into the bioreactor. (2016).cliffsnotes. This is because the transfer rate at the high temperature much faster than the lower temperature. 2017. 2017. where at the temperature 45˚C there is a little decreasing in value due to the error in conducting the experiment. Retrieved November.January 2018).CONCLUSION To be concluded the increasing in the agitation speed lead to the increasing in the mass transfer coefficient.org/biology/types-of-biochemical- reactions/lesson/Types-of-Biochemical-Reactions-BIO/ Kane. Transport Processes in Stirred Tank Bioreactors.ck12. The Scope of Biochemistry. Theoretically. (1 March. 2017 CliffNotes. the higher the temperature of the bioprocess system gives the highest mass transfer coefficient of that reaction.com/study- guides/biology/biochemistry-i/the-scope-of-biochemistry/types-of-biochemical- reactions Foundation. I. (2017). the highest value of mass transfer coefficient is affected by the highest agitation speed of the bioreactor’s impeller. 2012). P. US National Library of Medicine National Institutes of Health. Retrieved December.13 .nlm. from Oxygen mass transfer in a stirred tank bioreactor using different impeller configurations for environmental purposes: https://www. (7 January.com/upstream-processing/bioreactors/measuring-kla-for- better-bioreactor-performance-328029/ Karimi.4186/ej. 2013). 14.bioprocessintl.gov/pmc/articles/PMC3561095/ Painmanakul. 13(3).2009. (November. 2017. A. doi:10. 2009). Engineering Journal. http://www.nih. THEORETICAL PREDICTION OF VOLUMETRIC MASS TRANSFER COEFFICIENT (kLa) FOR DESIGNING AN AERATION TANK.13.ncbi.3. APPENDICES Figure 8: The nitrogen gas tank. . Figure 9: The oxygen gas supplier motor.