Conventional Tank Reactor Research Articles

The Effects of Photobioreactor Type on Biomass and Lipid Production of the Green Microalga Monoraphidium pusillum in Laboratory Scale

Mass production of microorganisms, algae among them, for new bioactive compounds and renewable innovative products is a current issue in biotechnology. The greatest challenge of basic research on this topic is to find the best solution for both physiology and scalability. In this study, the main goal was to highlight the contradictions of physiological and technological optimization in the same, relatively small, laboratory scale. The green alga Monoraphidium pusillum (Printz) Komárková-Legnorová was cultured in a conventional Erlenmeyer flask (as air bubbled in a tank-type photobioreactor) and in a hybrid (fermenter type + helical tubular type) photobioreactor of the same volume (2.8 L). Higher cell numbers from 1.7–2.3-fold, 2–2.8-fold higher dry masses, and 1.9–2.6-fold higher total lipid contents (mg·L−1) were measured in the tank reactor than in the hybrid reactor. Cultures in the conventional tank reactor were characterized with better nutrient utilization (42.8–77.7% higher phosphate uptake) and more diverse lipid composition than in the hybrid reactor. The study highlights that well-scalable arrangements and settings could be not optimal (or unsuitable in some cases) from a physiological point of view. The results suggest certain developmental directions for complex, well-scalable devices and highlight the importance of testing the gained physiological optima on these systems.

Improvement of the catalytic efficiency of Suzuki-Miyaura reaction depending on the numbering-up flow reactors

The increasing demands for the greener synthesis and the higher efficient strategy for the Suzuki–Miyaura reaction have motivated the development of new catalysts and processes due to its important application in pharmaceutics, petrochemicals, organic synthesis, polymer, etc. fields. In this work, different designs of numbering-up reactors were employed for the catalysis of Suzuki–Miyaura reaction based on a self-supporting palladium catalyst. Compared with the conventional tank reactor, the catalytic efficiency was improved more than 5 times depending on the numbering-up of reactors with a parallel connection. Furthermore, the influence of the different connection models on the catalysis was carefully compared. The high catalytic activity, good adaptability, and non-leakage of palladium bestowed upon this strategy with great potential in the large-scale application of the Suzuki-Miyaura reaction. Moreover, the synthesis of a self-supporting palladium catalyst (P(b-NHC-Pd)) with high molecular weight was presented. From the catalytic kinetics analysis, the activation energy of this catalyst decreased by 37% compared with that of tetrakis(triphenylphosphine)palladium. Thus, this self-supporting catalyst is highly promising for operation in a continuous flow reactor due to its high catalytic activity, excellent separability, and high stability.