Influence of impeller type on hydrodynamics and gas‐liquid mass‐transfer in stirred airlift bioreactor

Abstract

The influence of impeller type in a mechanically stirred airlift bioreactor was analyzed in relation to the non‐Newtonian viscous fluids. The agitation was carried out through a marine impeller (axial impeller) and a paddle impeller (radial impeller) located along with the gas sparger in the region comprised by the riser. The bioreactor was sparged with air under different velocities (0.036–0.060 m s−1). Carboxymethylcellulose 1.94% and xanthan 1.80% were used as a fluid model. The gas holdup and volumetric mass‐transfer coefficient increased in up to five and three times, respectively, when compared to a conventional airlift bioreactor; however, better results were obtained when the straight paddle impeller type was used. The results suggest that the studied bioreactor can be used successfully in viscous fluid, and it can be more efficient than conventional airlift bioreactors. The results obtained suggest the use of radial impellers. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3159–3171, 2015

Effect of Surface Tension on Hydrodynamics and Mass Transfer Coefficient in Airlift Reactors

“…Dynamic gassing , was applied to measure the overall gas‐liquid volumetric mass transfer coefficient ( k L a ). The dissolved oxygen probe was used to assess the dissolved oxygen concentration in the fluids.…”

Effect of Surface Tension on Hydrodynamics and Mass Transfer Coefficient in Airlift Reactors

“…Dynamic gassing , was applied to measure the overall gas‐liquid volumetric mass transfer coefficient ( k L a ). The dissolved oxygen probe was used to assess the dissolved oxygen concentration in the fluids.…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The comparison of the k L a per power density between our measurements in this work and those reported from previous literature ,,− is listed in Table , where the k L a and demonstrated k L a per P / V in this work is calculated according to the result of σ = 63.7 mN/m and P L / V L = 0.146 shown in Figure (d). As can be seen from the table, the jet-impinging type bubble generator offers a better energy efficiency than many bubble generating systems but cannot operate at a higher k L a compared with an array of downward microjets.…”

Coalescence‐inhibited dense bubble swarm with millimeter‐sized bubbles for interfacial mass transfer intensification

“…It can be concluded that the η decreases with the increase of k L a . As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ·kW −1 ·s −1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references 6,41,48–56 . In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2–#G4) in terms of either k L a or η .…”

“…As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ÁkW À1 Ás À1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references. 6,41,[48][49][50][51][52][53][54][55][56] In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2-#G4) in terms of either k L a or η. Thus, #G1 exhibits promising potential for industrial applications due to its advantages of high efficiency, dispensability of moving components, and excellent bubble stability.…”

Effect of Surface Tension on Hydrodynamics and Mass Transfer Coefficient in Airlift Reactors

“…Dynamic gassing , was applied to measure the overall gas‐liquid volumetric mass transfer coefficient ( k L a ). The dissolved oxygen probe was used to assess the dissolved oxygen concentration in the fluids.…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The comparison of the k L a per power density between our measurements in this work and those reported from previous literature ,,− is listed in Table , where the k L a and demonstrated k L a per P / V in this work is calculated according to the result of σ = 63.7 mN/m and P L / V L = 0.146 shown in Figure (d). As can be seen from the table, the jet-impinging type bubble generator offers a better energy efficiency than many bubble generating systems but cannot operate at a higher k L a compared with an array of downward microjets.…”

Coalescence‐inhibited dense bubble swarm with millimeter‐sized bubbles for interfacial mass transfer intensification

“…It can be concluded that the η decreases with the increase of k L a . As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ·kW −1 ·s −1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references 6,41,48–56 . In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2–#G4) in terms of either k L a or η .…”

“…As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ÁkW À1 Ás À1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references. 6,41,[48][49][50][51][52][53][54][55][56] In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2-#G4) in terms of either k L a or η. Thus, #G1 exhibits promising potential for industrial applications due to its advantages of high efficiency, dispensability of moving components, and excellent bubble stability.…”

Effect of Surface Tension on Hydrodynamics and Mass Transfer Coefficient in Airlift Reactors

“…Dynamic gassing , was applied to measure the overall gas‐liquid volumetric mass transfer coefficient ( k L a ). The dissolved oxygen probe was used to assess the dissolved oxygen concentration in the fluids.…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The comparison of the k L a per power density between our measurements in this work and those reported from previous literature ,,− is listed in Table , where the k L a and demonstrated k L a per P / V in this work is calculated according to the result of σ = 63.7 mN/m and P L / V L = 0.146 shown in Figure (d). As can be seen from the table, the jet-impinging type bubble generator offers a better energy efficiency than many bubble generating systems but cannot operate at a higher k L a compared with an array of downward microjets.…”

Coalescence‐inhibited dense bubble swarm with millimeter‐sized bubbles for interfacial mass transfer intensification

“…It can be concluded that the η decreases with the increase of k L a . As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ·kW −1 ·s −1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references 6,41,48–56 . In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2–#G4) in terms of either k L a or η .…”

“…As shown in Table S2, the maximum η value of #G1 is 0.793 m 3 ÁkW À1 Ás À1 , which indicates that CIDS exhibits higher energy efficiency than other methods in references. 6,41,[48][49][50][51][52][53][54][55][56] In addition, the performance of #G1 outperforms the other traditional bubble generators (#G2-#G4) in terms of either k L a or η. Thus, #G1 exhibits promising potential for industrial applications due to its advantages of high efficiency, dispensability of moving components, and excellent bubble stability.…”