Application of rotating packed bed for in‐line aroma stripping from cell slurry

Abstract

BACKGROUND: Nowadays, biotechnological production receives increasing interest as an alternative source of natural aromas. Unfortunately, especially for hydrophobic and semi-volatile aromas, the heterogeneous product partitioning between all phases present in fermentation makes recovery challenging. Additionally, when an aroma displays an inhibitory effect on the production microorganism, product removal during fermentation is recommendable. In-line aroma stripping offers an elegant way to deal with such challenges. This study reports the use of rotating packed bed (RPB) technology for the intensification of stripping of ⊍-ionone, a key aroma of raspberry, from a model fermentation slurry containing Saccharomyces cerevisiae cells in a concentration of 250 g-CWW L −1. RESULTS: Throughout all experimental investigations, yeast cells were robust towards both the chemical stress from aroma exposure at a concentration of up to 400 mg L −1 and the mechanical stress from peripheral equipment and rotation of up to 2750 rpm, as a maximum of 11.3 ± 0.5% disrupted cells were measured during continuous processing in an RPB. An increase in the rotation speed led to an enhanced transfer of ⊍-ionone from the fermentation slurry to the gaseous phase. CONCLUSIONS: RPB technology is found to be promising for the intensification of in-line stripping of biotechnologically produced aromas from crude fermentation broth without cell separation. The use of subsequent RPBs equipped with custom packings and flexibly adjustable rotation speed displays a holistic aroma recovery process supporting the way to commercial competitiveness of biotechnological aromas.

Zickzack Packings for Deaeration in Rotating Packed Beds─Improved Rotor Design to Counter Bypass Flows

“…Multiple design approaches have been proposed aiming at an even liquid distribution throughout the packing, like multiliquid-inlet rotors , and anisotropic wire mesh or foam packings with a changing morphology along the rotor. − In another approach, split packings with counter-rotating packing rings have been developed to increase phase slip along the packing′s radial length. ,− Gładyszewski and Skiborowski were the first to use additive manufacturing as a relatively inexpensive method for rapid prototyping of packings for RPBs. , Since then, three-dimensional (3D) printing has been used extensively to create tailored anisotropic as well as multiliquid-inlet wire mesh packings and different structured packings like the Zickzack packing and spiral packing leading to more homogeneously distributed liquid holdup. It is expected that the use of 3D printing will be a sustaining trend to customize packings for RPBs and to reveal the interactions between gas and liquid in the rotor …”

“…12,22−25 Gładyszewski and Skiborowski 26 were the first to use additive manufacturing as a relatively inexpensive method for rapid prototyping of packings for RPBs. 26,27 Since then, three-dimensional (3D) printing has been used extensively to create tailored anisotropic 28 multiliquid-inlet 29 wire mesh packings and different structured packings like the Zickzack packing 30 and spiral packing 31 leading to more homogeneously distributed liquid holdup. It is expected that the use of 3D printing will be a sustaining trend to customize packings for RPBs and to reveal the interactions between gas and liquid in the rotor.…”

Analysis of Flow Patterns in Structured Zickzack Packings for Rotating Packed Beds Using γ-Ray Computed Tomography

“…Thus, innovative packing designs are required to achieve efficient contacting of the fluid phases throughout the entire volume of an RPB packing. , In recent years, 3D printing technologies have emerged as a promising tool supporting the development of new packing designs . In addition to anisotropic and multiliquid-inlet wire-mesh packings, various special structured packings , were suggested to homogenize the liquid distribution.…”

“…3,12 In recent years, 3D printing technologies have emerged as a promising tool supporting the development of new packing designs. 13 In addition to anisotropic 14 and multiliquid-inlet 15 wire-mesh packings, various special structured packings 16,17 were suggested to homogenize the liquid distribution.…”

Radial Temperature Profile Measurements to Understand Mass Transfer in Rotating Packed Bed Distillation

“…The vapor stream is introduced into the casing and flows radially inward, whereas the liquid is introduced at the inner side of the annular packing and is accelerated radially outward toward the casing due to the centrifugal field. Rotational speed in an RPB offers an additional degree of freedom as the operating window and separation efficiency can be changed by changing the rotational speed. − …”