Continuous Reactor Research Articles

Comparison of continuous technologies for vegetable oils epoxidation

Epoxidized Vegetable Oils (EVOs) are an important class of chemical compounds obtained from biomass and used as intermediates to produce several bio-products and chemicals, such as hydroxy-alkoxy compounds, diols, amines, and carbonates. Epoxides originating from vegetable oils and their derivatives, namely fatty acids or alkyl esters, are still produced by semibatch technology which suffers from severe mass transfer limitations and long reaction times, thus impairing the final product selectivity and restraining the overall productivity. In this work, two continuous reactor technologies to produce epoxides from vegetable oils were developed and compared. The first configuration, consisting of only one jacketed tubular reactor operated in co-current up-flow mode, showed a good performance at T = 318 K achieving a double bond conversion exceeding 95 % and an epoxide selectivity higher than 90 %. The second technology, where two jacketed tubular reactors connected in series were operated in up-flow mode, gave comparable conversions and selectivity to the previous one, but under somewhat milder conditions, at T = 294 K and 298 K for the first and second reactor, respectively, and in the absence of any added acid catalyst. Following this latter concept, additional experiments were performed in the presence of different vegetable oils as starting materials to confirm the performance with more common feedstocks. Both configurations showed results that clearly exceed the performance of the current semibatch process.

Visible light driven ZnFe2O4 for the degradation of oxytetracycline in the presence of HSO5− at semi-pilot scale and additional H2 production

This study investigated the synthesis of visible light driven ZnFe2O4 for photocatalytic degradation of oxytetracycline (OTC) in a continuous flow reactor and production of hydrogen (H2). OTC is widely used as a medication and found to create severe health and environmental issues. The use of advanced characterization techniques proved successful formation of ZnFe2O4 which was found to be reusable, stable, highly crystalline, and nano-sized. The prepared ZnFe2O4 caused 60% removal of OTC and removal efficiency of the latter was promoted to 85% by adding HSO5– with ZnFe2O4 at 240 min employing reactor flow rate of 0.1 L/min and concentrations of ZnFe2O4, OTC, and HSO5– as 1.0 g/L, 20 mg/L, and 100 mg/L, respectively. The addition of HSO5– was found to give hydroxyl radical (•OH) and sulfate radical (SO4•−) and the latter caused degradation of OTC into degradation products. The removal of OTC was promoted by factors facilitating the rate of formation of •OH and SO4•−. The ZnFe2O4 proved effective in photocatalytic H2 production and showed H2 production rate of 23.4 μmol h−1 g−1. The results suggest that ZnFe2O4 could be used as an economically viable technology for emerging pollutants degradation and green energy production.

New Modeling Approaches for Ethylene Oxychlorination in Fluidized Bed Reactors: Industrial and Low Flow Rate Conditions

A simple model (Continuous Stirred-Tank Reactor) has been developed to predict the behavior of industrial ethylene oxychlorination fluidized beds operating in a turbulent regime. The approach showed good agreement both with results from industrial reactors and with those corresponding to the (Simple two phases-Plug bubble-Mixed flow emulsion approach) validated in the literature. For low flow rates, the use of the (Simple two phases - Plug bubble - Plug emulsion model) adapted to these conditions enabled us to highlight the location and extent of undesirable thermal hot spots for the process, and to propose actions to control them by acting on the temperature and/or on the feed gas flows. By comparing this model with the plug approach, the significant slowdown in ethylene conversion caused by resistance to mass transfer when feed flow rates are low is highlighted. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Solar-driven chloride activation via 3D oxygen-vacancy-rich TiO2 network photoanode for ultrafast and durable purification of saline wastewater

Photoelectrochemical chloride activation (PEC-Cl) is a promising and reagent-free strategy to treat saline organic wastewater by activation of chloride (Cl–) using sunlight. However, the low efficiency and Cl– corrosion of photoelectrode, and the limited mass transfer of pollutant hinder its application. Herein we successfully solve these challenges by developing porous oxygen-vacancy-rich TiO2 nanoneedle arrays (TiO2 NNs-r400) photoanode. Under illumination, the photoinduced holes in TiO2 NNs-r400 oxidize Cl– to reactive species (e.g., HOCl, Cl•, Cl2•− and ClO•), resulting in the degradation rate of tetracycline hydrochloride (HTC, 0.861 min−1) by TiO2 NNs-r400/PEC-Cl system is 2–3 orders of magnitude higher than the state-of-the-art. Experiments and computational analysis indicate that oxygen vacancies (Ovs) on TiO2 NNs-r400 promote the photocarriers separation efficiency and more importantly, facilitate Cl– adsorption with intermediary strength and reduce the energy barriers of Cl– oxidation. Furthermore, we design a continuous flow-through PEC reactor for TiO2 NNs-r400/PEC-Cl technology. The process exhibits 100% HTC degradation (TOC = 60.23%) for over 2000 h flow-through operation, which maintains high activity in the treatment marine aquaculture wastewater with nearly zero energy consumption by directly utilize natural sunlight. In the final effluent, the toxicity of almost all degradation intermediates is decreased, and the formation of total organic chlorine is low (17.2 µg L–1). This work provides insights into Cl– activation on Ov-rich photoanode and strategy for practical application of solar energy in efficient, sustainable and eco-friendly wastewater decontamination.

Synthesis of bentonite-supported Ni, La, and Ca catalysts for hydrogen production through steam reforming of acetic acid

In this study, the production of hydrogen-rich gas through the steam reforming of acetic acid using bentonite-supported catalysts was investigated. Bentonite was treated by washing and calcination. Bentonite-supported Ni, Ca, La, Ni–La, and Ni–Ca catalysts with different active metal loadings of 10 and 30 wt% were synthesized using the wet impregnation method. The catalysts were characterized using XRD, XRF, SEM, EDS, BET, FT-IR, NH3-TPD, and Raman. The activity tests of the catalysts were carried out in a continuous flow tubular reactor at various temperatures (500, 600, 700, and 800 °C). Product gas composition was determined by gas chromatography (μ-GC). The effect of bentonite treatment, active metal type, and bimetallic combinations (Ni/Bent, Ni/Bent*, La/Bent, Ca/Bent, Ni–La/Bent, and Ni–Ca/Bent) were studied. The highest hydrogen yield obtained without a catalyst was 8.61% at 700 °C. This yield increased to 74.5% at 600 °C with 30 wt% Ni–La/Bentonite, and to 42.6% with 30 wt% Ni/Bentonite catalysts, respectively. The experimental results show that bentonite has a suitable catalytic activity on its own and is a promising support material for the steam reforming of acetic acid.

Assessment of an eco-efficient process for the optimization of metal recovery in lithium cobalt oxide and lithium nickel manganese cobalt oxide batteries

The expansion of technology motivates the increase of global demands for critical minerals. In this context, the exploration of secondary sources of these components is expanding. End-of-life batteries can be seen as potential sources of lithium, cobalt, nickel and manganese for electric vehicles or diverse applications in electronic equipments. This paper provides a comprehensive evaluation of the recovery of metals from waste batteries with diverse chemistry composition. Lithium cobalt oxide (LCO) and lithium nickel cobalt manganese oxide (NMC) batteries were co-treated with polyvinyl chloride (PVC) channels under supercritical water, varying reaction temperature (400–600 °C) and PVC/Battery composition (0–3 m/m) in a tubular continuous reactor. Results show high recovery rates for all metals, with up to 90% percentage recovery of lithium and cobalt in all cases. Temperature and feed composition were identified as determining factors for the recovery of lithium from LCO batteries. In the case of cobalt, temperature was identified as the most important factor that affects its recovery. The selected optimal conditions for cobalt recovery in the solid products of reactions were identified for batteries LCO and NMC: temperature of 600 °C and PVC/Battery ratio of 3.0 and temperature of 500 °C and PVC/Battery ratio of 1.5, respectively. Environmental impacts, primarily Global Warming Potential (GWP), were minimal, with 4.71·10−5 kg CO2 eq., indicating the benefits of the process as an eco-efficient and promising route for the recycling of valuable metals.

Scale-Up, Continuous and Low-Temperature Production of Multimetal Based Electrocatalysts toward Water Electrolysis.

Electrocatalytic water splitting is a crucial strategy for advancing hydrogen energy and addressing the global energy crisis. Despite its significance, the need for a straightforward and swift method to synthesize electrocatalysts with exceptional performance remains pressing. In this study, we demonstrate a novel approach for the preparation of multimetal-based electrocatalysts in a continuous flow reactor, enabling the quick synthesis of a large number of products through a streamlined process. The resultant NiFe-LDH comprises nanoflakes with a high specific surface area and requires only 255.4 mV overpotential to achieve a current density of 10 mA·cm-2 in 1 M KOH, surpassing samples fabricated by conventional hydrothermal methods. Our method can also be applied to craft a spectrum of other multimetal-based electrocatalysts, including CoFe-LDH, CoAl-LDH, NiMn-LDH, and NiCoFe-LDH. Additionally, the NiFe-LDH electrocatalyst is further applied to anodic methanol electrooxidation coupled with cathodic hydrogen evolution. Moreover, the simplicity and generality of our fabrication method render it applicable for the facile preparation of various multimetal-based electrocatalysts, offering a scalable solution to the quest for high-performance catalysts in advancing sustainable energy technologies.

Dynamic decarburisation model of AOD process: Based upon the FactSage-Macro Programme

Improving the quality of stainless-steel hinges significantly on precisely managing decarburisation within the argon-oxygen decarburisation (AOD) process. This study introduces a dynamic model capable of accurately predicting the composition and weight of steel and slag. To thoroughly investigate the refining processes, a systematic analysis was conducted, integrating three essential adiabatic zones within the AOD converter: the continuous stirred-tank reactor, slag bath and plug flow reactor, supported by circulation and recirculation streams. FactSageTM software and its macro facility were utilised to identify the different phases present in steel and slag. This dynamic model not only forecasts critical process parameters like temperature, composition and volume of multiple phases but also enables the prediction of the final chromium content for different initial carbon inputs, specifically at 2%, 1.5% and 1 wt.%. By comparing the model's predictions with actual plant data, it was observed that the transient compositions of steel and slag exhibited consistency, confirming the model's validity and reliability in simulating AOD refining processes.

Continuous flow-through electro-Fenton membrane reactor with Fe−N4-doped carbon membrane as cathode for efficient removal of dimethylacetamide

Fe − N4-doped conductive carbon membranes (FeCMs) were fabricated through high-temperature carbonization using chitosan and phenolic resin as the raw materials and ammonium ferrous sulfate (NH4Fe(SO4)2) as the dopant. The impact of the NH4Fe(SO4)2 doping rate (0 − 15 wt%) on the structure and performance of the FeCM was investigated. Moreover, a continuous flow-through electro-Fenton membrane reactor (EFMR) was constructed using an FeCM cathode and a Ti plate anode for the efficient removal of dimethylacetamide (DMAC). The resultant carbon membrane with 10 wt% NH4Fe(SO4)2 (M10) exhibited a smaller pore size (40.1 nm), a higher porosity (48.3 %), a larger specific surface area (531.6 m2/g), and a higher mechanical strength (6.7 M Pa) than the other membranes. The removal rate of DMAC by EFMR with M10 as the cathode at 2 V reached 42.1 %, which was much greater than that without NH4Fe(SO4)2 (3.6 %). The electrosynthesis ·OH concentration by EFMR with M10 as the cathode was approximately 89.1 mg/L, which was much greater than that of most carbon-based materials. The intermediates of DMAC degradation (such as N-methylacetamide, acetamide, acetaldehyde, and acetic acid) were determined by gas chromatography–mass spectrometry (GC–MS), and the removal of total organic carbon (TOC) was approximately 3.4 %. Density functional theory (DFT) calculations revealed that the Fe atom served as the active site for dissolved oxygen adsorption and electrogeneration of ·OH. After 5 days of continuous EFMR operation, the DMAC removal rate remained at 88.8 % of the initial value (42.1 %). This study presents a novel approach for designing and fabricating conductive carbon membranes to improve industrial wastewater treatment performance.

Multilayer polyelectrolyte and palladium nanoparticle decorated porous materials as fixed-bed reactors for efficient reduction of 4-NP

In this study, a continuous flow catalytic reactor based on three-dimensional porous sponge bed with the uniform distribution of catalyst to treat 4-NP wastewater efficiently. The porous sponge is used as a support to construct polyelectrolyte multilayers by loading dopamine. And the multilayer polyelectrolyte is closely bound to dopamine to form polyelectrolyte film, and the nanocatalysts are synthesized by electrostatic adsorption of precursors. The reactor realizes the uniform and stable distribution of the catalyst in the three-dimensional porous sponge, and the reactant transfers from bulk solution to catalyst surface by the way of convection and diffusion, which enhances mass transfer and further improves the reaction efficiency. Under the operating conditions of a catalytic bed as small as 3 cm, a 4-NP concentration up to 4.5 mM, and a flow rate of 300 μL min−1, the conversion rate remained above 96 % for up to 200 h, indicating that the reactor has good catalytic efficiency. The results showed that this continuous flow catalytic system structure has excellent performance in wastewater treatment.

Phase–activity relationship of MnO2 nanomaterials in periodate oxidation for organic pollutant degradation

Manganese dioxide (MnO2), renowned for its abundant natural crystal phases, emerges as a leading catalyst candidate for the degradation of pollutants. The relationship between its crystal phase and catalytic activity, particularly for periodate activation, has remained both ambiguous and contentious. This study delineates the influence of various synthetic MnO2 phase structures on their capabilities in catalyzing periodate-assisted pollutant oxidation. Five distinct MnO2 phase structures (α-, β-, γ-, δ-, and ε-MnO₂) were prepared and evaluated to activate periodate and degrade pollutants, following the sequence: α-MnO₂ > γ-MnO₂ > β-MnO₂ > ε-MnO₂ > δ-MnO₂. Through quenching experiments, electron paramagnetic resonance tests, and in situ electrochemical studies, we found an electron transfer-mediated process drive pollutant degradation, facilitated by a highly reactive metastable intermediate complex (MnO₂/PI*). Quantitative structure-activity relationship analysis further indicated that degradation efficiency is strongly associated with both the crystal phase and the Mn (IV) content, highlighting it as a key active site. Moreover, the α-MnO₂ phase demonstrated exceptional recycling stability, enabling an effective pollutant removal in a continuous flow packed-bed reactor for 168 h. Thus, α-MnO₂/PI proved highly effective in mineralizing organic pollutants and reducing their toxicities, highlighting its significant potential for environmental remediation.

Improved performance and mechanism of the long-term vanadium(V) remediation by immobilization of rice washing waste

There is an urgent need to develop more efficient microbial technologies suitable for vanadium (V) stressed environments. In this study, rice washing waste (RWW) was utilized as both the carbon and microbial sources immobilized together with sludge to treat V-containing wastewater. Continuous flow reactors were operated, and V(V) removal efficiencies (30 d) with polyvinyl alcohol (PVA) and chitosan as embedded carriers achieved 9.0% and 79.4%, respectively. A superior V(V) removal performance (91.45%) was achieved in the continuous flow reactors with chitosan-based immobilized materials (70 d). V was detected on the surface and within the material, and V(IV) was found, indicating that both adsorption and microbes were able to contribute to V(V) remediation. Increase in the fractions of some functional microbes were observed in response to V(V) stress (unclassified_f_Comamonadaceae, unclassified_f_Enterobacteriaceae) and ammonia stress (unclassified_f_Hungateiclostridiacea). RWW could serve as suitable carbon and microbial sources for long-term operation and enhance V(V) removal by immobilized together with sludge, thereby unveiling a new method for both food and V contaminants.

PLS-based hellinger distance method for fault detection in chemical engineering systems

Fault detection is vital in chemical engineering systems to maintain operational efficiency, product quality, and safety through timely identification and correction of deviations from expected behavior. Although partial least squares (PLS) has proven effective in monitoring due to its ability to handle highly correlated variables, traditional detection metrics of PLS may fail to identify small abnormal changes as they rely solely on recent observations. This paper integrates PLS modeling framework with Hellinger Distance (HD)-based fault detection index to overcome the limitations of conventional detection metrics. The utilization of HD is motivated by its sensitivity to quantifying any dissimilarity between distributions, which makes it well-suited for detecting small deviations in process behavior. The HD-based index will be computed between the residuals obtained from the model in the offline stage and the online stage. The HD metric involves careful inspection and comparison of the residuals, which enables it to capture the sensitive details in the data, thus, enhancing the detection of faults. For increased flexibility, kernel density estimation is employed to establish the reference threshold of the PLS-HD approach. The performance of this approach will be evaluated using data from simulated Continuous Stirred-Tank Heater (CSTH) and Continuous Stirred-Tank Reactor (CSTR) processes, by considering various fault types such as bias, freezing, and sensor drift faults. The results demonstrate the superior performance of the proposed PLS-HD approach compared to conventional PLS monitoring methods.

Investigation of thermolabile particles for debonding on demand in fiber reinforced composites

AbstractGlass fiber reinforced plastics (GFRP) are essential for lightweight design and are manufactured in high quantities. Since there is no suitable method for recycling, the GFRP are mostly grinded and used as filler at end of life. In this work, the well-known principle of debonding on demand is considered to enable feasible and value-retaining separation of glass fibers from the polymeric matrix. To this end, gas-releasing thermo-responsive substances (TRS) like carboxylic or amino acids are introduced to the composite to investigate their potential for causing delamination after heating. To promote sufficient fiber/matrix adhesion, the TRS are encapsulated with silica or immobilized on magnetite particles. Furthermore, the immobilization synthesis is scaled up by using a custom-made continuous flow reactor. Finally, a new sizing mixed for glass fiber spinning, containing the particles, is formulated. The experiments reveal that a maximum of 0.5 wt.% particles can be used in the sizing to coat the fibers. Although all tested samples show a significant organic functionalization, the particles functionalized with TRS do not trigger sufficient delamination at the current state of development.

Co-Digestion and Mono-Digestion of Sewage Sludge and Steam-Pretreated Winter Wheat Straw in Continuous Stirred-Tank Reactors—Nutrient Composition and Process Performance

Wheat straw (WS) constitutes a considerable biomass resource and can be used to produce the energy carrier methane through anaerobic digestion. Due to the low contents of several nutrient elements and water in harvested WS, the use of sewage sludge (SS), consisting of primary sludge and waste-activated sludge, as a nutrient source in co-digestion with steam-pretreated wheat straw (PWS) was investigated theoretically and practically. WS was steam-pretreated, with acetic acid as the catalyst, at 190 °C for 10 min, ending with a rapid reduction in pressure. Process stability and specific methane production were studied for the mono-digestion and co-digestion of PWS and SS in continuous stirred-tank reactors for 208 days. The HRT was 22 days and the OLR 2.1 gVS L−1 d−1. In co-digestion, the OLR was increased to 2.8 gVS L−1 d−1 for one week. Nutrient elements were added to PWS mono-digestion at two different concentration levels. Co-digestion was stable, with a total concentration of short-chain fatty acids (SCFAs) at a safe level below 0.35 g L−1 at both OLRs. The higher OLR during co-digestion would require an increase in reactor volume of 14%, compared to the mono-digestion of SS, but would increase the annual production of methane by 26%. The specific methane production levels for PWS mono-digestion, SS mono-digestion, and co-digestion were 170, 320, and 260 mL g−1VS, respectively. Co-digestion did not result in a synergistic increase in the methane yield. SCFAs accumulated in the mono-digestion of PWS when using lower levels of nutrient supplements, and the concentrations fluctuated at higher nutrient levels. The main conclusion is that PWS and SS can be co-digested with long-term process stability, without the addition of chemicals other than water and acetic acid. The specific methane production for mono-digestion of PWS was relatively low. The effect of using higher concentrations of micronutrients in PWS mono-digestion should be evaluated in future studies.

Main features of a novel extraction-hydrogenation unit

The potential for coupling a continuous hydrogenation reactor with a continuous extraction unit was investigated through computer simulation of series of mixers/settlers coupled to a slurry reactor in a closed loop.The process has the potential to replace the regeneration of extraction solvents by distillation. Additionally, the system eliminates the need to treat the entire feedstock when refining a complex mixture. It is believed that the reaction of the extract retains valuable components in the feed that are not extracted and could undergo undesirable hydrogenation.The parameters for the simulation model were obtained from correlations and published data. The system was expected to exhibit a pseudo-first-order reaction rate in relation to the impurity concentration due to its low concentration in the extract. This is expected to result in high hydrogen-to-impurity ratios, which can be advantageous from a reaction driving force perspective.Solvent degradation by hydrogenation and solvent-impurity reactions are thought to be the main problems for the extraction-hydrogenation process.

Exploring an Electrochemical Batch Reactor for Nutrient Recovery from Wastewater: Continuum Modeling Analysis of Hydrodynamics and Tertiary Current Distribution

Advancing electrochemical reactors for nutrient recovery from wastewater requires an integration of continuum modeling alongside experimental investigations to appropriately capture transport effects on electrode performance. This continuum modeling approach facilitates the comprehensive evaluation and optimization of electrochemical reactor performance, especially with respect to intricate phenomena that may be challenging to observe solely through experimentation. The optimization process not only enhances the efficacy of existing batch reactors but also lays the foundation for designing and scaling up continuous electrochemical reactors for nutrient recovery [1].A key transport phenomenon in electrochemistry is hydrodynamics because flow dynamics around electrodes dictate mass transport magnitude and uniformity, thereby impacting current distribution, efficiency, and electrolytic energy consumption during electrolysis. Achieving homogeneous velocity fields while avoiding undesirable flow features is essential to prevent non-uniform potential and current density distributions along the electrodes, mitigating side reactions and ensuring the overall efficacy of the electrochemical processes [2].In this study, a two-dimensional model of an electrochemical batch reactor was developed using COMSOL Multiphysics software to investigate reactor hydrodynamics, electrochemical reactions, and mass transfer of species. Employing the finite element method, the model incorporated the k-epsilon turbulence model for hydrodynamics simulation, widely used in literature for simulating fluid flow and mixing behavior [3]. Electrochemical reactions at the cathode (oxygen reduction) were modeled using the Butler-Volmer equation, while the Tafel equation was applied at the anode (hydrogen evolution). Boundary conditions were a grounded counter electrode (anode) and a potential of -1.1 vs Ag/AgCl(sat.) applied to the working electrode (cathode). Fick's second law diffusion-convective equation was employed to model the mass transfer of species, including hydroxide and oxygen.Preliminary findings indicate that while impellers contribute to turbulence and affect local conditions around electrodes, the impact on the backside of the modeled electrodes is relatively weak (Figure 1). This observation may adversely influence mass transfer rates and electrochemical reactions, underscoring the significance of integrating these results with electrochemical reactions for a comprehensive understanding of reactor behavior. Additional results will be presented at the meeting.

A microbiome-biochar composite synergistically eliminates the environmental risks of antibiotic mixtures and their toxic byproducts

This study developed a continuous reactor system employing a hybrid hydrogel composite synthesized using a complex sludge microbiome and an adsorbent (HSA). This HSA-based system effectively eliminated the environmental risks associated with a mixture of the antibiotics ciprofloxacin and sulfamethoxazole, which exhibited higher toxicity in combination than individually at environmentally relevant levels. Analytical chemistry experiments revealed the in-situ generation of various byproducts (BPs) within the bioreactor system, with two of these BPs recording toxicity levels that surpassed those of their parent compound. The HSA approach successfully prevented the functional microbiome from being washed out of the reactor, while HSA efficiently removed antibiotic residues in their original and BP forms through synergistic adsorptive and biotransformation mechanisms, ultimately reducing the overall ecotoxicity. The use of HSA thus demonstrates promise not only as a mean to reduce the threat posed by toxic antibiotic residues to aquatic ecosystems but also as a practical solution to operational challenges, such as biomass loss/washout, that are frequently encountered in various environmental bioprocesses.

Enhancement of thermostability and expression level of Rasamsonia emersonii lipase in Pichia pastoris and its application in biodiesel production in a continuous flow reactor

The acidic lipase from Rasamsonia emersonii named LIPR has great potential for biodiesel synthesis due to its strong methanol tolerance. Nonetheless, the limited thermostability of LIPR and low expression level in Escherichia coli remain major obstacles to its use in biodiesel synthesis. To enhance the thermostability, the mutant LIPR harboring mutations A126C-P238C for the formation of a new disulfide bond and amino acid substitution D214L was obtained through rational design. To our delight, the thermostability of LIPR mutant was greatly improved. Moreover, a comprehensive optimization strategy, such as employing the Mss signal peptide, co-expressing the molecular chaperone protein disulfide isomerase (PDI), knocking out the vacuolar sorting receptor gene VPS10-01, and overexpressing the dihydroxyacetone synthase gene DAS2, was adopted to obtain the combination-optimized mutant Pichia pastoris strain GS54. Furthermore, the biodiesel synthetic capability with the mutant GS54-LIPR was verified and the production yield was 52.2 % after 24 h in a shake flask. Subsequently, a continuous flow system was adopted to increase the biodiesel yield to 73.6 % within 3 h, demonstrating its efficacy in enhancing enzyme biocatalysis. The engineered GS54-LIPR mutant lipase is an efficient and reusable biocatalyst for the sustained production of biodiesel in a continuous flow reaction.

Modeling and experimental study on a photochemical microscale continuous oscillatory baffled reactor

AbstractHerein, the first photochemical microscale continuous oscillatory baffled reactor, that is, Photo‐μCOBR, was designed and evaluated. Computational fluid dynamics simulations were used to optimize the key structural parameter and operating conditions. Then, the mixing process was simulated and the μCOBR was shown to be more than 23 times faster than the straight channel both under oscillating conditions. Finally, a glass Photo‐μCOBR was fabricated by femtosecond laser internal engraving technology, and the photocatalytic gas–liquid oxidation of dihydroartemisinic acid was performed. A yield of 65.9% was achieved in a residence time of ~120 s and at a gas–liquid flow rate ratio of 1:3 (vs. 18.6% in the capillary photomicroreactor under identical conditions). The results in this work offer guidelines for the design and operation of microscale COBRs, and the as‐fabricated Photo‐μCOBR displays good potential for gas–liquid photochemical reactions.