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Bulk chemicals, such as carbon monoxide (CO) and ethylene glycol (EG), derived from biomass feedstocks instead of traditional fossil fuels present a renewable and sustainable energy alternative. However, their direct production under ambient conditions with high purity is challenging. Herein, we report a distinctive photochemical process to produce CO together with EG through the ultrafast C–C cleavage of dihydroxyacetone induced by ultraviolet illumination at ambient temperature and pressure in water. The obtained CO yield was nearly 98% with a high purity above 99.9%, and the EG yield was nearly 80%. The two hydroxyls at the alpha carbons of dihydroxyacetone reduced the energy barriers of photoexcitation and the radical reaction, accounting for fast C–C cleavage to produce CO and EG. A home-built flow reactor achieved the continuous production of CO and EG over 1000 h and maintained efficient operation for 100 h in the sunlight-electricity-ultraviolet light mode. Benefitting from the fast reaction rate and high-purity gas generation, a safe, laboratory-scale, portable, ready-to-use CO generator was designed and assembled. The maximum CO production rate of the CO generator reached 30 mL min−1, and CO purity reached over 99% for 25 L. [ABSTRACT FROM AUTHOR]

A sustainable method suitable for industrial-scale continuous flow synthesis of esters from biomass-derived furfuryl alcohol (FA) and C8–C18 carboxylic acids was developed. Under optimized reaction conditions, lipase from Aspergillus oryzae immobilized on an octyl-silane MgO·SiO2 material demonstrated high activity. A conversion of 88.7–90.2% for FA with 100% selectivity to esters using a FA : fatty acid molar ratio of 1 : 3 and cyclohexane as the solvent at 25 °C in 45 min was achieved in a batch system. The biocatalyst retained its high activity for at least 10 consecutive reaction cycles. Successful upgradation from a batch to continuous flow reactor led to an increased FA conversion of up to 96.8%, with a reagent flow rate of 0.070 mL min−1 and a residence time of 10.5 minutes. The biocatalyst maintained excellent performance for 30 h. The developed method, considered within the framework of green chemistry metrics, ensures a balance between the high activity, stability, recyclability, and biodegradability of the catalyst. This work proposes as a generic approach to green chemistry dedicated to support the biocatalytic continuous flow synthesis of value-added chemicals. [ABSTRACT FROM AUTHOR]

In this work, the performance of a series of noble metal catalysts supported on the SBA-16 mesoporous matrix was studied. Its activity was measured in catalytic hydrotreating (HDT) reactions, such as tetralin hydrogenation in a batch reactor. The results were adjusted with a pseudo first order equation and then, the most active catalysts were tested in a continuous flow reactor under industrial-like conditions. Noble metal catalysts were synthesized, mainly monometallic iridium and bimetallic iridium-platinum and iridium-palladium supported SBA-16. The support was also modified with aluminum to provide Bronsted and Lewis acidity to the catalysts. All the catalysts were characterized by FTIR, XRD, NMR, N2 isotherms, H2 chemisorption, TPR and XPS to be able to relate the activity with the nature of the catalyst. The catalyst modified with 0.5 wt% of Ir, 0.5 wt% of Pt and 3 wt% of Al supported over SBA-16 matrix was the most active in tetralin hydrogenation to decalins in a Batch reactor, achieving the higher kinetic constant of 0.012 min−1 and 90% of conversion to fully hydrogenated decalins at 120 min of reaction time. This catalyst also was the most active in the hydrogenation of tetralin using a continuous flow reactor obtaining the highest kinetic constant of all the catalysts tested with a value of 0.152 mol/h g cat. and achieving 90% of conversion to decalins at W/F = 150. Its greater activity was explained in terms of greater hydrogenating capacity, better dispersion of the active species, and greater resistance to deactivation thanks to the protective effect of the bimetallic alloy formed in synergy with a greater acidity of the aluminum-modified support. In this work, optimization has been achieved in the synthesis of an active, selective, contaminant-resistant catalyst with great stability. Very good results were obtained in a continuous process under conditions like to industrial ones. [ABSTRACT FROM AUTHOR]

With peculiar structural features at the surface of small metal nanoparticles, some discrete sites can display catalytic behaviour similar to what could be observed with mononuclear metal catalysts in solution. We have studied the transfer of two catalytic tandem reactions from homogeneous to heterogeneous conditions. Tandem cyclisation/reduction of ortho-alkynyl benzaldehyde derivatives was successfully achieved with Au nanoparticles over TiO2 (Au NPs/TiO2) in the presence of Hantzsch ester with 45-98% yields for 15 examples (average yield: 70.4%). Similarly, tandem cyclisation/hydroalkoxylation of ortho-alkynyl benzaldehyde derivatives was successfully achieved with Au NPs/TiO2 in methanol or other alcohols with 62-96% yields for 17 examples (average yield: 84.9%). The application potential of this catalytic system was demonstrated with the total synthesis of a bioactive isochromene derivative featuring one of the developed reactions as the key step and the implementation of the tandem cyclisation/hydroalkoxylation in a continuous flow reactor, scaling up the reaction by a factor of 10 without loss of efficiency. Heterogeneous catalysis offers a range of advantages over homogeneous catalysis, but transferring a reaction from homogeneous to heterogeneous protocols is highly challenging. Here, the authors study the transfer of two catalytic tandem reactions—a cyclization/reduction and a cyclization/hydroalkoxylation—from homogeneous to heterogeneous conditions, using gold nanoparticles to generate isochromene derivatives from ortho-alkynyl benzaldehyde starting materials, and demonstrating scalability in flow. [ABSTRACT FROM AUTHOR]

Continuous flow synthesis is pivotal in dye production to address batch‐to‐batch variations. However, synthesizing water‐insoluble dyes in an aqueous system poses a challenge that can lead to clogging. This study successfully achieved the safe and efficient synthesis of azo dyes by selecting and optimizing flow reactor modules for different reaction types in the two‐step reaction and implementing cascade cooperation. Integrating continuous flow microreactor with continuous stirred tank reactor (CSTR) enabled the continuous flow synthesis of Sudan Yellow 3G without introducing water‐soluble functional groups or using organic solvents to enhance solubility. Optimizing conditions (acidity/alkalinity, temperature, residence time) within the initial modular continuous flow reactor resulted in a remarkable 99.5% isolated yield, 98.6 % purity, and a production rate of 2.90 g h−1. Scaling‐up based on different reactor module characteristics further increased the production rate to 74.4 g h−1 while maintaining high yield and purity. The construction of this small 3D‐printing modular cascaded reactor and process scaling‐up provide technical support for continuous flow synthesis of water‐insoluble dyes, particularly high‐market‐share azo dyes. Moreover, this versatile methodology proves applicable to continuous flow processes involving various homogeneous and heterogeneous reaction cascades. [ABSTRACT FROM AUTHOR]

The application of immobilized enzymes often plays a key role in successfully implementing an economically feasible biocatalytic process at an industrial scale. Designing an immobilized biocatalyst involves solving several tasks, from the selection of the carrier and immobilization method to the characterization of the kinetic properties of the immobilized enzyme. In this study, we focused on the kinetic properties of free and immobilized ß-N-acetylhexosaminidase (Hex), a promising enzyme for application in the field of biotechnology, especially for the synthesis of bioactive carbohydrates. Hex was immobilized via covalent binding in methacrylate particles. The effect of immobilizing Hex from Penicillium oxalicum into porous particles on kinetic properties was investigated, and mathematical and experimental modeling showed that the kinetic behavior of the enzyme was significantly influenced by diffusion in the particles. Along with the study on kinetics, a simple method was developed to investigate the reversible inhibition of the immobilized enzyme in a continuous-flow system. The method is suitable for application in cases where a chromogenic substrate is used, and here it was applied to demonstrate the inhibitory effects of N-acetyl-glucosaminyl thiazoline (NAG-thiazoline) and O-(2-Acetamido-2-deoxy-D-glucopyranosylidene)amino N-phenyl carbamate ((Z)-PugNAc) on Hex. [ABSTRACT FROM AUTHOR]

The objective of this study is to conduct a thorough hazard analysis specifically tailored to identify hazards and suggest precautions associated with the intricate process of dimethyl ether (DME) production. This exothermic nature of DME production introduces the critical concern of thermal runaway. Furthermore, the DME synthesis process demands precise control over both pressure and flow rate. These parameters are important for increasing DME selectivity and CO conversion. Inadequate monitoring of these values may not only prevent the synthesis from proceeding but may also lead to major risks to health and safety. For this reason, proactive measures must be implemented to eliminate or minimize the risks. The significance of such measures cannot be overstated, as they serve to safeguard not only the integrity of the synthesis process but also the surrounding environment and human health. To delve deeper into the hazard evaluation, a comprehensive Hazard and Operability (HAZOP) analysis has been carried out, focusing specifically on the reactor within the DME process. This methodical examination involves a systematic review of potential deviations, identifying the associated hazards, and proposing effective preventive measures. The HAZOP analysis serves as a pivotal tool in ensuring the overall safety and reliability of the DME process. [ABSTRACT FROM AUTHOR]

Nitrospira is a common genus of nitrite-oxidising bacteria (NOB) found in wastewater treatment plants (WWTPs). To identify the key factors influencing the composition of NOB communities, research was conducted using both sequencing batch reactor (SBR) and continuous flow reactor under different conditions. High-throughput 16S rRNA gene sequencing revealed that Nitrospira (18.79% in R1 and 25.77% in R3) was the dominant NOB under low dissolved oxygen (DO) and low nitrite (${\rm NO}_2^-$ NO 2 − -N) concentrations, while Nitrobacter (21.26% in R2) was the dominant NOB under high DO and high ${\rm NO}_2^-$ NO 2 − -N concentrations. Flocculent and granule sludge were cultivated with Nitrospira as the dominant genus. Compared to Nitrospira flocculent sludge, Nitrospira granule sludge had higher inhibition threshold concentrations for free ammonia (FA) and free nitrous acid (FNA). It was more likely to resist adverse environmental disturbances. Furthermore, the effects of environmental factors such as temperature, pH, and DO on the activity of Nitrospira granular sludge were also studied. The results showed that the optimum temperature and pH for Nitrospira granular sludge were 36°C and 7.0, respectively. Additionally, Nitrospira granular sludge showed a higher dissolved oxygen half-saturation constant (Ko) of 3.67 ± 0.71 mg/L due to its morphological characteristics. However, the majority of WWTPs conditions do not meet the conditions for the Nitrospira granular sludge. Thus, it can be speculated that future development of aerobic partial nitrification granular sludge may automatically eliminate the influence of Nitrospira. This study provides a theoretical basis for a deeper understanding of Nitrospira and the development of future water treatment processes. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a versatile oxidant, and its eco-friendly synthesis via visible light and air oxygen is crucial. Anthraquinone compounds were employed as homogeneous photocatalysts for alcohol oxidation, yielding H2O2 under visible light. Instead of using traditional catalyst library screening, a model based on density functional theory was proposed to structurally optimize anthraquinone photocatalysts, resulting in the discovery of a novel catalyst significantly boosting H2O2 generation (up to 621.2 mM h-1 intermittently). Continuous flow reactor design improvements can enhance chemical transformation efficiency, as demonstrated by continuous H2O2 production using 2,6-di-tert-butyl anthraquinone. When isopropanol was used as the hydrogen atom donor, H2O2 production rates reached 3950.6 mM h-1 in a 7-minute reaction, with a space--time yield of 7.90 mol (L h) -1, showcasing promising advancements in green H2O2 synthesis. [ABSTRACT FROM AUTHOR]

The influence of the deposition of nanoparticles of an aerosol, moving in a continuous reactor at a constant velocity, on the channel walls of the reactor and of the coagulation of these particles as a result of their Brownian diffusion on the nanoaerosol parameters was investigated. A simple one-dimensional model, adequately defining the diffusion, coagulation, and deposition of nanoaerosol particles in a wide range of change in its Knudsen number, has been constructed. It is shown analytically that, as the distance from the inlet of the reactor increases, the volume fraction of particles in the nanoaerosol decreases by the exponential law, and the radius of the clusters formed in the nanoaerosol as a result of the coagulation of its particles increases and tends to a limiting (maximum) value. A nonlinear integro-differential equation for the radius of such clusters has been obtained, and, from it, compact formulas for approximate calculation of its limiting radius have been derived. The characteristic distributions of the radii of clusters and of their concentrations along the reactor channel, calculated by the numerical method, are presented. It was established that, if this channel has a fairly large length, the clusters moving in it increase to their limiting size. The influence of the determining parameters of the flow of a nanoaerosol at the inlet to the continuous reactor on the distribution of its dispersion characteristics along the reactor channel, on the limiting size of the clysters in it, and on the characteristic length of the channel, at which the processes of deposition and coagulation of nanoaerosol particles are completed, is discussed. A comparison of the results of calculations of the parameters of a nanoaerosol moving in a continuous reactor by the one- and two-dimensional models has shown that the simple one-dimensional model defines the behavior of these parameters quite adequately. [ABSTRACT FROM AUTHOR]

Ammonia recovery from wastewater is crucial for mitigating environmental impact and complying with regulatory standards. Therefore, this study aimed to explore the potential of a pilot scale continuous flow crystallizer reactor to recover ammonia from urea fertilizer plant wastewater through struvite crystallization. On the basis of the principles validated in previous batch experiments, continuous flow crystallizer reactor was designed and operated using identified optimal parameters. Reactor was fed with synthetic wastewater containing ammonia concentration of 500-1000 mg/L and operated under varying hydraulic retention times of 3-5 hours. The influent concentrations of MgCl2 · 6H2O and KH2PO4 were adjusted to match the ammonia concentration in reactor, maintaining a molar ratio of Mg:NH4:PO4 at 1:1:1, with pH between 9 and 10. The results showed that over 90% of ammonia was removed and recovered as struvite crystals, with a mean size of 0.1 to 1 mm, allowing for effective sedimentation and harvesting. This showed that the reactor could potentially handle higher loading and achieve greater removal rates. Furthermore, effluent concentration met the standards set by the Indonesian government for the urea fertilizer sector, specifically for discharge into seawater. The study showed the feasibility of using continuous flow crystallizer reactor for efficient ammonia recovery through struvite crystallization. This method reduced the ammonia levels in the effluent, thereby mitigating environmental impact, and produced struvite, which could be used as a slowrelease fertilizer to improve economic value. The promising results suggested the potential for further development and industrial application of this method to address the environmental and economic challenges associated with ammonia-containing wastewater. [ABSTRACT FROM AUTHOR]

Owing to their capability to produce reactive oxygen species (ROS) under solar irradiation, covalent organic frameworks (COFs) with pre-designable structure and unique architectures show great potentials for water purification. However, the sluggish charge separation, inefficient oxygen activation and poor structure stability in COFs restrict their practical applications to decontaminate water. Herein, via a facile one-pot synthetic strategy, we show the direct conversion of reversible imine linkage into rigid thiazole linkage can adjust the π-conjugation and local charge polarization of skeleton to boost the exciton dissociation on COFs. The rigid linkage can also improve the robustness of skeleton and the stability of COFs during the consecutive utilization process. More importantly, the thiazole linkage in COFs with optimal C 2p states (COF-S) effectively increases the activities of neighboring benzene unit to directly modulate the O2-adsorption energy barrier and improve the ROS production efficiency, resulting in the excellent photocatalytic degradation efficiency of seven toxic emerging contaminants (e.g. degrading ~99% of 5 mg L−1 paracetamol in only 7 min) and effective bacterial/algal inactivation performance. Besides, COF-S can be immobilized in continuous-flow reactor and in enlarged reactor to efficiently eliminate pollutants under natural sunlight irradiation, demonstrating the feasibility for practical application. Linking COFs by rigid thiazole linkages can simultaneously enhance the stability, charge separation efficiency, and oxygen activation capability of COFs, resulting in the excellent photocatalytic degradation performance towards micropollutants in water. [ABSTRACT FROM AUTHOR]

Water resources are indispensable basic resources and important environmental carriers; the presence of organic contaminants in wastewater poses considerable risks to the health of both humans and ecosystems. Although the Fenton-like reactions using H2O2 as the oxidant to destroy organic pollutants are attractive, there are still challenges in improving reaction activity under neutral or even alkaline conditions. Herein, we designed a H2O2 activation pathway with O2•- as the main active species and elucidated that the spin interaction between Fe sites and coordinated O atoms effectively promotes the generation of the key intermediate Fe-*OOH. Furthermore, we successfully captured and analyzed the Fe-*OOH intermediate by in situ Raman spectroscopy. When applying FBOB to a continuous-flow reactor, CIP removal efficiency remained at around 90% within 600 min of continuous operation, achieving excellent efficiency, stability, and pH tolerance in removing pollutants. [ABSTRACT FROM AUTHOR]

Lubricant base oils, traditionally derived from non-renewable petroleum, contribute significantly to greenhouse gas emissions. In contrast, oils sourced from furfural and long-chain ketones through aldol condensation and hydrodeoxygenation present a renewable, cost-effective, and environmentally friendly alternative, offering superior cold flow properties. However, the production of long-chain ketones, a crucial component, currently relies on solvent dewaxing in refineries, which is costly and non-selective. One promising biobased approach involves self-ketonization of long-chain fatty acids derived from coconut or palm kernel oils. This method typically employs high boiling point solvents like dodecane or is done in a batch configuration, limiting its scale and industrial viability. This study addresses this bottleneck by eliminating solvents, transitioning to a continuous flow reactor, and achieving kilogram-scale production of long-chain ketones with exceptional selectivity (90%). The lab-scale setup can yield up to 25 kg of 12-tricosanone per month, utilizing earth-abundant MgO as a catalyst. The catalyst underwent slight deactivation due to carbonate formation. Catalyst stabilization, using mixed metal oxides, and regeneration via simple calcination in air are also discussed. Techno-economic analysis (TEA) indicates a 29% lower minimum selling price than the commercial synthetic poly alpha olefin (PAO). Life cycle assessment (LCA) evaluates the global warming potential (GWP) under different environmental assumptions. Under the carbon-neutral assumption for lauric acid production, an 8.9% reduction in GWP was achieved compared to petroleum-based lubricants. [ABSTRACT FROM AUTHOR]

Partial denitrification granular sludge (PDGS) can provide long-term stable nitrite for anaerobic ammonia oxidation (anammox). The cultivation of ordinary activated sludge from wastewater treatment plants into PDGS can further promote the application of PD in practical engineering. In this study, the feasibility of fast start-up of PDGS was explored by inoculating waste sludge in up-flow anaerobic sludge blanket (UASB) reactor with synergistic control of nitrogen load rate (NLR, 0.05–0.65 kg N/m3/d) and electron donor starvation (EDS) (240–168 mg L−1), and system performance, particle characteristics and microbial structure were studied. The results showed that PD-UASB started successfully within 48 days, the average nitrite accumulation rate (NTR) and nitrate removal ratio (NRR) reached 79.6% and 82.5% after successful initiation, accompanied by high abundance of PD bacteria (Thauera, Pseudomonas, unclassflied commamonadaceae and Limnobacter) (25.3%). The increase of PD activity, and the difference between nitrate reductase (NAR) and nitrite reductase (NIR) contributed to nitrite production. Besides, the sludge shifted from flocculated (≤0.5 mm, 95.37%) to granulated state (0.5–2 mm, 64.74%), which could be due to the increase of extracellular polymers (EPS) (especially T-EPS) and metabolism of specific microorganisms (Bacteroidota and Chloroflexi, 19.92%). Good sludge granulation promoted the settleability of PD (the SVI5 was 47.248 mL/ g. ss after successful start-up). In summary, good PD sludge granulation process could be achieved in a short time by synergistically controlling NLR and EDS. [ABSTRACT FROM AUTHOR]

The sustainable synthesis of long carbon chain molecules from carbon dioxide, water and electricity relies on the development of waste‐free, highly selective C−C bond forming reactions. An example for such a power‐to‐chemicals process is the industrial‐scale fermentation for the production of hexanoic acid. Herein, we describe how this product is transformed into 6‐undecanone via decarboxylative ketonization using a heterogeneous manganese oxide/silica catalyst. The reaction reaches full conversion with near‐complete selectivity when carried out in a continuous flow reactor, requires no solvent or carrier gas, and releases carbon dioxide and water as the only by‐products. The reactor was operated for several weeks with no loss of reactivity, producing 7 kg of 6‐undecanone from 10 g of catalyst and achieving a productivity of 1.135 kg per litre of reactor volume per hour. 6‐Undecanone and other long‐chain ketones accessible this way can be hydrogenated to industrially meaningful alkanes, or converted into valuable fatty acids via a hydrogenation/elimination/isomerizing hydrocarboxylation sequence. [ABSTRACT FROM AUTHOR]

The optimization of wastewater treatment technologies using biological processes is no longer limited to improving the removal of organic matter and nutrients, as it is possible to reduce area and energy consumption, and recover value-added by-products. In this context, the microalgae–bacteria consortium is an alternative for reducing costs, as microalgae produce the oxygen required by bacteria to oxidize organic matter through photosynthesis. Additionally, it is possible to extract different by-products such as lipids, biofertilizers, biogas, alginate-type exopolymers, and others. Furthermore, bioflocculation occurs naturally through the adhesion of microalgae to the surface of bacterial flocs, without the addition of chemical products. This review discusses the main systems that utilize the microalgae–bacteria consortium, the metabolism of the microalgae–bacteria consortium, and its performance in removing organic matter and nutrients, as well as the effect of operating conditions on the physical properties of the biomass. Among the highlighted systems are sequencing batch and single-batch reactors, high-rate ponds, and continuous flow reactors. Among the systems discussed in this work, the sequential batch reactor configurations found better biomass formation and production of extracellular polymeric substances and the continuous flow reactors showed lower installation and operating costs. From this perspective, the potential for full-scale application of each system can be evaluated once the optimum operating conditions have been defined and the limitations of each system have been understood. [ABSTRACT FROM AUTHOR]

The traditional batch synthesis of liquid rubber faces issues such as low monomer polymerization concentration, poor uniformity of the reaction system, and inadequate heat dissipation, resulting in an unsatisfactory synthesis efficiency. This study presents a method for the rapid and efficient synthesis of high vinyl 1,2‐polybutadiene liquid rubber using butadiene as the monomer and n‐butyllithium as the initiator. By applying continuous flow microchannel reactors, the limitation of traditional synthesis method can be overcome. The addition of a modifier in the raw material promotes the formation of high vinyl structure. The preparation of liquid rubber requires the addition of a large amount of metal lithium initiator. However, for aerospace sealants, there is a requirement for low metal ion content. To address this, we employed different methods to reduce the metal ion content in the liquid rubber and increase its purity. Ultimately, we achieved the synthesis of high‐purity polybutadiene liquid rubber with 1,2‐vinyl content exceeding 88%, narrow molecular weight distribution, and tunable molecular weights. This research will provide technical guidance for the industrial application of polybutadiene synthesis in continuous flow microchannel reactors. [ABSTRACT FROM AUTHOR]

This study analysed the formation of biofilms in the drinking water distribution system in Wroclaw. The focus was on the influence of the material from which pipes in water distribution systems are built: polyethylene (PE) and polypropylene (PP). Two reactors with continuous water flow were used. Once the quasi- steady state was determined, an analysis was carried out to measure the total number of microorganisms per unit volume, which were stabilised without affecting further changes in concentration, and to study the basic physicochemical parameters of water that can affect the microbial growth that forms. In addition, a literature review was conducted to analyse biofilm formation based on physicochemical parameters in the water distribution system. Psychrophilic bacteria were shown to be more numerous than mesophilic bacteria, with the growth rate of the latter being higher. An increase in the number of microorganisms was observed, with higher concentrations found on PE surfaces because the rougher surface structure provides better adhesion for biofilm-forming microorganisms than on a surface made of polypropylene (PP). The presence of mesophilic bacteria may indicate the potential for pathogenic microorganisms, as well as the formation of a primary biofilm characterised by irreversible attachment to the substrate. These findings suggest that synthetic materials such as PE are more susceptible to biological growth than polypropylene (PP) as a result of their uneven surface structure, which facilitates the deposition of biofilm-forming organisms. The preliminary results can be used as an important reference for future research related to biofilms in drinking water distribution systems. [ABSTRACT FROM AUTHOR]

This study explores the influence of flow velocity, sphere size, and inter-sphere distance on hydrodynamics and mass transfer in a photocatalytic reactor. The effects of two different light configurations on light distribution and degradation were also evaluated. A 2D computational fluid dynamics (CFD) model was developed to simulate the continuous flow photocatalytic reactor with TiO2-coated spheres and validated with experimental measurements by observing the degradation of methyl orange. The experimental setup consists of a tube containing an equal number of TiO2-coated glass spheres. The case with radiation from one wall shows a non-uniform light distribution compared with the case with radiation from both walls. The CFD simulations focused on analyzing the velocity streamlines and turbulence characteristics (turbulent kinetic energy (TKE) and turbulence dissipation rate (TDR)). These parameters showed significant variations in each studied case. The case with larger spheres reached the highest velocity of 38 m/s of the pollutant solution. The highest TKE and TDR values of 0.47 m2/s2 and 12.2 m2/s2, respectively, were also observed in the same case, indicating enhanced mixing and mass transfer to the catalyst surfaces, ultimately leading to a more efficient degradation process. The results show that an optimized design of photocatalytic reactors can significantly improve mass transfer and, thus, degradation efficiency. [ABSTRACT FROM AUTHOR]

Moving bed biofilm reactors (MBBRs) are compact biofilm systems that provide a sustainable solution for biological nitrogen removal. A study was conducted on an innovative post-denitrification method as a polishing step to reduce low nitrate nitrogen concentrations (10 mg/L) to 2.1–4.9 mg/L. The objective was to minimize residual chemical oxygen demand (COD) in the effluent caused by the external carbon source required for this final treatment step. Therefore, four continuous flow reactors with varying synthetic loads and hydraulic retention times (HRTs), as well as two carrier sizes, were operated over 335 days. The results showed that an HRT of 2 h is necessary to successfully reduce the residual COD to 5–6 mg/L. Additionally, it was demonstrated that the protected volume of the biofilm carriers has a significant impact on MBBRs compared to the protected surface, which is commonly discussed in the literature. The available protected volume can limit biofilm growth, as demonstrated by measuring the total biofilm solids (TBS) and biofilm thickness on the carrier at varying COD eliminations. When providing sufficient protected volume for the biofilm through the filling ratio and carrier size, a COD elimination rate of 1.4 to 1.45 kg/(m3d) was achieved with a biofilm thickness of only 500 µm. [ABSTRACT FROM AUTHOR]

The present study focuses on the technique of hardness removal by using a novel reactor performing an electrocoagulation (EC) process. The variation of alkalinity is also recorded. Continuous flow experiments were conducted for Total Hardness (TH) removal using a transparent plastic reactor using aluminum plate electrodes that have holes so that the water flows through the plates in a zigzag way. The influence of various operating parameters such as the number of plates (two and four), flow rate (600, 1000 L/h), and water type (Tigris River & rejected water from Reverse Osmosis system RO) was investigated. The results showed that an increase in the number of electrodes led to an increase in the total hardness removal efficiency. In addition, the increase in the flow rate led to a decrease in the removal efficiency. For the rejected RO water type, the highest hardness removal rate was 16.16% for 4 plates electrodes and 600 L/h flow rate while for the river water was 29% for 4 plates electrodes and 1000 L/h [ABSTRACT FROM AUTHOR]

This study aimed to explore the impact of varying amounts of added Au (0.5 to 2 wt.%) and the structural characteristics of anatase TiO2 supports (nanoparticles (TP, SBET = 88 m2/g) and nanorods (TR, SBET = 105 m2/g)) on the catalytic efficiency of TiO2+Au catalysts in eliminating the herbicide glyphosate from aqueous solutions via the catalytic wet air oxidation (CWAO) process. The investigation was conducted using a continuous-flow trickle-bed reactor. Regardless of the TiO2 support and the amount of Au added, the addition of Au has a positive effect on the glyphosate degradation rate. Regarding the amount of Au added, the highest catalytic activity was observed with the TP + 1% Au catalyst, which had a higher Schottky barrier (SB) than the TP + 2% Au catalyst, which helped the charge carriers in the TiO2 conduction band to increase their reduction potential by preventing them from returning to the Au. The role of glyphosate degradation product adsorption on the catalyst surface is crucial for sustaining the long-term catalytic activity of the investigated TiO2+Au materials. This was particularly evident in the case of the TR + 1% Au catalyst, which had the highest glyphosate degradation rate at the beginning of the CWAO experiment, but its catalytic activity then decreased over time due to the adsorption of glyphosate degradation products, which was favoured by the presence of strong acidic sites. In addition, the TR + 1% Au solid had the smallest average Au particle size of all analyzed materials, which were more easily deactivated by the adsorption of glyphosate degradation products. The analysis of the degradation products of glyphosate shows that the oxidation of glyphosate in the liquid phase involves the rupture of C–P and C–N bonds, as amino-methyl-phosphonic acid (AMPA), glyoxylic acid and sarcosine were detected. [ABSTRACT FROM AUTHOR]

l‐Pipecolic Acid (l‐PA) is a valuable building block for the synthesis of pharmaceuticals such as anesthetics and immunosuppressants. Thus, more efficient and greener strategies are desired for its production. Herein, we have applied a previously engineered variant of the Lysine Cyclodeaminase from Streptomyces pristinaespiralis (e‐SpLCD) for the bioconversion of l‐Lysine into l‐PA. The reaction can be performed by the free e‐SpLCD reaching full conversion to 50 mM l‐PA. From a biotechnological perspective, the process scale‐up has been trialed in a SpinChem® reactor, albeit with lower conversion yields. To further enhance the biocatalyst stability, we present a detailed study of the e‐SpLCD immobilization on microparticles. This enabled the integration of the immobilized biocatalyst into a packed‐bed reactor for the continuous flow synthesis of l‐PA. The full conversion was achieved in 90 min, maintaining also high operational stability. Remarkably, the addition of exogenous cofactor was not needed for the flow reaction, although the long‐term operational stability was improved by the addition of NAD+. [ABSTRACT FROM AUTHOR]

A green strategy for the selective alkylation of cysteine-containing peptides in a continuous flow reactor has been developed, providing an efficient pathway to alkylated cysteine-containing peptides under mild conditions. This process does not need light, metal catalysts, or oxidative reagents. It provides a useful method for the modification of amino acids and peptides. As one of the low cost and synthetic versatile raw materials, the alkyl thianthenium salt can be used as an alkylation source in the preparation of alkylated cysteine-containing peptides. In addition, the microfluidics technology can shorten the reaction time and improve the efficiency, thus reducing the costs and energy consumption of the synthesis process. A series of alkylated cysteine-containing peptides (41 examples) has been synthesized here with a short residence time (14.0 min), and with good to excellent yields. [ABSTRACT FROM AUTHOR]

Herein, we present a novel, hydrazine-free photoredox catalyzed platform for azine synthesis using mild, simple reaction conditions. While previous energy transfer activations of oxime esters lead to decarboxylation of the O-auxiliary and radical combination with the iminyl radical, the reductive electron transfer strategy herein affords high yields of azines using only a triarylamine organophotocatalyst and no additives. Scale up was readily achieved by means of a continuous flow reactor. Mechanistic studies indicate a preassembly of photocatalyst and substrate is key to achieving efficient and selective N–N iminyl radical coupling. [ABSTRACT FROM AUTHOR]

Cu catalysts with different compositions and different Cu and promoter contents were prepared by precipitation‐gel method and studied for the selective hydrogenation of syngas or biomass‐based diethyl malonate (DEM) to valuable 1,3‐propanediol (1,3‐PDO). The Ga‐promoted 70Cu6Ga/SiO2 catalyst was found to exhibit the highest catalytic performance, achieving 100 % DEM conversion and 76.6 % 1,3‐PDO selectivity under reaction conditions of 160 °C and 8 MPa H2. The 70Cu6Ga/SiO2 bimetallic catalyst also presented obviously better stability than that of the monometallic 70Cu/SiO2 catalyst in a continuous flow reactor over 180 h time‐on stream. Characterization results showed that the incorporation of Ga increased the interaction between Cu and Ga species, hindered the full reduction of Cu2+ species, and thus increased the proportion of Cu+ and the number of Lewis acidic sites on the catalyst surface. The synergistic effect between Cu0 and Cu+ enhanced the adsorption and activation of ester carbonyl groups and their subsequent hydrogenation, eventually contributed to the outstanding performances of the CuGa/SiO2 bimetallic catalysts. [ABSTRACT FROM AUTHOR]

Textile and food industries produce huge amounts of wastewaters containing dye residues. When these wastewaters are discharged to receiving surface waters like as lakes and rivers, aesthetically unpleasant situations form. Therefore, these wastewaters should be treated. Wastewater treatment is sometimes an expensive operation and cheap methods should be developed. The removal of Indigo Carmine (I.C., Acid dye) and Brilliant Yellow (B.Y., Azo dye) from synthetically prepared solutions was studied by coagulation using iron chloride salt in a batch reactor at room temperature. As an experimental approach, two leveled factorial design with three factors was applied as a function of pH (4-12), iron chloride amount (0.1-0.4 g/500 mL) and dye concentration (100-200 mg/L). Low pHs supported to removal of these two dyes. The results showed that 100% I.C. dye removal and 90.5% B.Y. dye removal were achieved. The all parameters were statistically insignificant for both the dyes. Indigo Carmine and Brilliant Yellow dyes were removed from solutions successfully. The applied treatment method was evaluated as promising due to low sludge production, low cost, low coagulation duration and high performance. A time span of 5 minutes was found as enough for removals of both of the dyes. After treatment of I.C. and B.Y. dyes by coagulation, the coagulated dyes were determined as unreusable due to iron complex by these dyes. Flocculation was found to be ineffective. A continuous flow reactor was successfully adopted for these dyes. [ABSTRACT FROM AUTHOR]

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BACKGROUND: Carbon (C) source consumption in industrial bioreactors removing soluble selenium (Se) contributes to the operating cost and can influence the rate of removal. This study used a laboratory chemostat to investigate the dependency of the rate of dissolved Se removal on the concentration of acetate and methanol, two C sources used in treatment of Se containing mine‐influenced water. It was hypothesized that the rate of dissolved Se removal follows a Monod kinetic model with C source as the limiting substrate. RESULTS: A chemostat fed with 25 mg‐selenate‐Se L−1 and acetate as C source at different concentrations operated over a range of hydraulic retention times (HRTs) achieved maximal removal of 99.7% dissolved Se at an HRT of 1.5 days [rate 16.7 mg‐Se (L day)−1]. When methanol was fed into the chemostat as the C source instead of acetate, the extent and rate of removal were much less [65% at an HRT of 6 days, rate 2.7 mg‐Se (L day)−1]. Carbon source consumption per mole of dissolved Se removed was not constant and exceeded stoichiometric estimates. Monod kinetic parameters for the Dechloromonas/Ralstonia consortium growing on acetate were estimated as KC= 3.36 mg‐C L−1 and YX/Cqmax,C= 0.70 L day−1. The Methylophilaceae consortium growing on methanol did not exhibit Monod kinetic growth. CONCLUSIONS: Using acetate as a C source achieved greater efficiency of dissolved Se removal than when methanol was used. Total dissolved Se removal rate was dependent on acetate only at low concentrations and when the HRT was close to washout. However, total dissolved Se removal rate was strongly dependent on HRT when methanol was used. © 2024 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The design of new and more sustainable synthetic protocols to access new materials or valuable compounds will have a high impact on the broader chemistry community. In this sense, continuous‐flow photochemistry has emerged as a powerful technique which has been employed successfully in various areas such as biopharma, organic chemistry, as well as materials science. However, it is important to note that chemical processes must not only advance towards new or improved chemical transformations, but also implement new technologies that enable new process opportunities. For this reason, the design of novel photoreactors is key to advancing photochemical strategies. In this sense, the use of equipment and techniques embracing processes intensification is important in developing more sustainable protocols. Among the most recent applications, spinning continuous flow reactors, such as rotor reactors or vortex reactors, have shown promising performance as new synthetic tools. Nevertheless, there is currently no review in the literature that effectively summarizes and showcases the most recent applications of such type of photoreactors. Herein, we highlight fundamental aspects and applications of two categories of spinning reactors, the Spinning Disc Reactors (SDRs) and Thin Film Vortex reactors, critiquing the scope and limitations of these advanced processing technologies. Further, we take a view on the future of spinning reactors in flow as a synthetic toolbox to explore new photochemical transformations. [ABSTRACT FROM AUTHOR]

We have developed a straightforward and cost-effective construction of continuous-flow electrochemical reactors using readily available metal wires and carbon fibers as electrodes. Teflon tubing, known for its chemical resistance and temperature tolerance, served as the flow channels. The flow length and material of the electrodes can be easily adjusted. Moreover, precise control of the reaction temperature is possible. As a proof of concept, environmentally benign halogenations of alkenes, alkynes, and aromatics were developed using easy-to-handle halide salts such as LiBr and LiCl as the halogen sources. [ABSTRACT FROM AUTHOR]

This study addresses the pressing issue of bilge water pollution from ships, a highly oily and hazardous wastewater source. The research employs the electrooxidation/flotation process, known for its effectiveness in organic matter removal. Key parameters, such as initial pH, current density and flow rate, were investigated for their impact on the removal of chemical oxygen demand (COD) and oil‐grease (OG) from bilge water. Initial pH showed minimal effects on COD and OG removal, while current density significantly enhanced removal efficiency by influencing anodic electrochemical reactions. Conversely, higher flow rates reduced residence time and lowered removal efficiency. Optimal conditions, with a current density of 10 mA/cm2, pH 7.5 and a flow rate of 20 ml/min, achieved impressive results, removing approximately 80% of COD and 99% of OG from bilge water. These findings highlight the potential of this method for effective bilge water purification. Highlights: Bilge water treatment is very important in terms of water pollution.A continuous flow electrochemical reactor was used for bilge water treatment.With the EO‐EF treatment process, 99% oil‐grease and 80% COD removal were obtained.The results provided a new approach for the treatment of industrial wastewater containing oil. [ABSTRACT FROM AUTHOR]

Traditional H2O2 cleavage mediated by macroscopic electron transfer (MET) not only has low utilization of H2O2, but also sacrifices the stability of catalysts. We present a non‐redox hydroxyl‐enriched spinel (CuFe2O4) catalyst with dual Lewis acid sites to realize the homolytic cleavage of H2O2. The results of systematic experiments, in situ characterizations, and theoretical calculations confirm that tetrahedral Cu sites with optimal Lewis acidity and strong electron delocalization can synergistically elongate the O−O bonds (1.47 Å → 1.87 Å) in collaboration with adjacent bridging hydroxyl (another Lewis acid site). As a result, the free energy of H2O2 homolytic cleavage is decreased (1.28 eV → 0.98 eV). H2O2 can be efficiently split into ⋅OH induced by hydroxyl‐enriched CuFe2O4 without MET, which greatly improves the catalyst stability and the H2O2 utilization (65.2 %, nearly 2 times than traditional catalysts). The system assembled with hydroxyl‐enriched CuFe2O4 and H2O2 affords exceptional performance for organic pollutant elimination. The scale‐up experiment using a continuous flow reactor realizes long‐term stability (up to 600 mL), confirming the tremendous potential of hydroxyl‐enriched CuFe2O4 for practical applications. [ABSTRACT FROM AUTHOR]

We present a novel, greener chloromethylation procedure for organosolv aspen lignin under mild reaction conditions without Lewis acid as a catalyst and in acetic acid as a solvent. This synthetic protocol provides a reliable approach to chloromethylated lignin (CML) and means to obtain valuable lignin derivatives. The resulted CML was subsequently transformed into 1‐methylimidazolium lignin (ImL), which effectively serves as a stabilizing agent for Pd/CuO nanoparticles (Pd/CuO−NPs). To evaluate the versatility of developed lignin‐based catalyst, we investigate its performance in a series of carbon‐carbon bond formation reactions, including Suzuki‐Miyaura, Sonogashira, Heck reactions, and azide‐alkyne cycloaddition (click) reaction. Remarkably, this catalyst exhibited a high degree of catalytic efficiency, resulting in reactions with yields ranging from average to excellent. The heterogeneous catalyst demonstrated outstanding recyclability, enabling its reuse for at least 10 consecutive reaction cycles, with yields consistently falling within the range of 42 % to 84 %. A continuous flow reactor cartridge prototype employing Lignin@Pd/CuO−NPs was developed, yielding results comparable to those achieved in batch reactions. The utilization of Lignin@Pd/CuO−NPs as a catalyst showcases its potential to facilitate diverse carbon‐carbon bond formation reactions and underscores its promising recyclability, aligning with the green chemistry metrics and principles of sustainability in chemical processes. [ABSTRACT FROM AUTHOR]

Screw extruders as continuous flow reactors allow the synthesis of new polymers, preparation of polymer blends and composites, and modification or functionalization of commercially available polymers. Literature data shows that the twin screw extrusion is the most popular solution used for this purpose. In contrast, the number of scientific papers on alternative methods, such as multi-screw extruders, is somewhat limited. This paper is the first review of the application of planetary roller extruders in the compounding and reactive processing of polymer blends and composites. To fill current knowledge gaps, we discuss the advantages and disadvantages of planetary roller extruders compared to other screw extruders. Moreover, we summarize recent advances in planetary roller extrusion in producing thermal sensitive and biodegradable polymeric materials, rubber compounds, materials for 3D printing, or plastics and rubber recycling. This work also proposes the possible scenarios for further sustainable development of polymer blends and composites using planetary roller extruders. [ABSTRACT FROM AUTHOR]

This study investigates the design of a serpentine continuous photocatalytic reactor for the degradation of methylene blue (MB) dye as a model contaminant of the synthetic textile wastewater under sunlight irradiation using supported zinc oxide nanorods (ZnO NRs) catalyst. ZnO NRs were fabricated on glass substrates using the microwave-assisted hydrothermal method and characterized by different techniques. The characterized results show that wurtzite crystal structure ZnO NRs has native defects in the visible region. Water contact angle measurement shows the highest wettability of ZnO NRs surface at pH 8. Photocatalytic degradation was conducted with MB dye under sunlight in a batch system followed by a continuous flow reactor. In the batch reactor, three different concentrations of 10, 50, and 100 ppm MB were examined under sunlight. MB degradation reached 100%, 83%, and 62% under sunlight for 10, 50, and 100 ppm, respectively, after 3 h of irradiation. In the continuous flow reactor, 100 ppm MB was degraded 80%, 67%, 58%, and 46% at flow rates of 1.5, 2.5, 4.5, and 6.0 ml/min, respectively. The photocatalytic degradation of MB dye follows pseudo-first-order with the highest absorption rate constant of about 0.0066 h-1 obtained for 1.5 ml/min flow rate. Furthermore, a multi-step process using a continuous flow reactor achieved ~ 90% MB degradation after five repeated steps. Moreover, the reusability of ZnO NRs catalysts was conducted for five repeated cycles using two different cleaning methods of used ZnO NRs, whereby the photo cyclic cleaning process achieved 71%, and the regular cleaning process attained only 45% degradation. [ABSTRACT FROM AUTHOR]

The catalytic reforming of bioethanol can produce green hydrogen (H2) and acetic acid (AcOH). In the present study, the conversion of aqueous ethanol (EtOH) over 4 wt%Ru-4 wt%Sn/TiO2 in a flow reactor was investigated at different temperatures at 0.1 MPa or at various pressures at 260 °C. The ethanol conversion was rather slow in liquid water, while the reactivity increased significantly when water was evaporated. Under gas-phase conditions at 0.1 MPa, the conversion rate increased with increasing reaction temperature, but the AcOH yield and H2 purity decreased due to by-production of CH4, CO, and CO2. The CH4 and CO generated by fragmentation of acetaldehyde (AA), an intermediate, were suppressed by increasing reaction pressure, although the formation of CH4 and CO2 generated from AcOH was pressure independent. Thus, the highest-pressure conditions in steam at a given reaction temperature are preferred for the production of pure H2. The initial step, EtOH → AA, was the rate-determining reaction, and the model experiments using AA as a substrate showed that the Cannizzaro reaction of two AA molecules to form EtOH and AcOH occurred preferentially. This oxidation system was confirmed to be effective at EtOH concentrations of up to 500 g/L in water. [ABSTRACT FROM AUTHOR]

Transition‐metal catalysts with metal nanoparticles (NPs) as active sites are widely utilized in various reactions. In this work, we report the atomic decoration of Pt upon Co NPs for enhanced catalytic performances in oxidation esterification. Systematical characterizations imply the single‐atom nature and homogeneous distribution of Pt throughout the formed single‐atom alloy (SAA). The synergistic interactions between Pt and Co lead to significant charge redistribution and up‐shifted density of states (DOS) toward the Fermi level, which are verified favorable for the adsorption and activation of substrates. The esterification performances of Pt1Co@C are evaluated in the transformation of 54 kinds of aromatic alcohols (5‐hydromethylfurfural, furfural, and benzyl alcohols) into the corresponding mono‐ and diesters. Pt1Co@C shows not only remarkably enhanced reactivity but also reliable durability in both batch and continuous flow reactors. Mechanism investigations clearly reveal the rapid transformation of 5‐hydromethylfurfural over Pt1Co@C through a simplified route with reduced energy barriers. [ABSTRACT FROM AUTHOR]

The use of reactive gaseous reagents for the production of active pharmaceutical ingredients (APIs) remains a scientific challenge due to safety and efficiency limitations. The implementation of continuous‐flow reactors has resulted in rapid development of gas‐handling technology because of several advantages such as increased interfacial area, improved mass‐ and heat transfer, and seamless scale‐up. This technology enables shorter and more atom‐economic synthesis routes for the production of pharmaceutical compounds. Herein, we provide an overview of literature from 2016 onwards in the development of gas‐handling continuous‐flow technology as well as the use of gases in functionalization of APIs. [ABSTRACT FROM AUTHOR]

In this study, we introduce an efficient, metal-free electrocatalytic desulfurative protocol for forming C–N bonds by selectively activating inert C(sp3)–S bonds of alkyl thioethers. This method offers a straightforward and environmentally friendly approach for modification of heterocyclic compounds from readily accessible thioethers. Preliminary mechanistic investigations suggest that the reaction proceeds via a carbocation intermediate. Furthermore, successful synthesis on a 10-gram scale was achieved in a continuous flow electrochemical reactor. [ABSTRACT FROM AUTHOR]

The Journal of Flow Chemistry has released a special issue titled "Emerging Investigators in Flow Chemistry 2023," which features the work of early career researchers in academia and industry who have made significant contributions to the field. The articles in this issue cover a diverse range of scientific perspectives and approaches, showcasing the wide range of backgrounds and expertise of the contributors. The goal of this special issue is to encourage collaboration and expand the scientific community and readership of the journal. The document provides brief biographical information about the researchers, highlighting their educational background, research interests, and notable achievements. Their work focuses on various aspects of flow chemistry, including the development of new therapeutic options, the application of flow microreactor technology, and the advancement of sustainable methodologies. [Extracted from the article]

Photochemistry and continuous flow chemistry are synthetic technology platforms that have witnessed an increasing uptake by chemical industries interested in complex organic molecule synthesis. Simultaneously, automation and data science are prominent targets in organic synthesis and in chemical industries for streamlined workflows, meaning hardware-software interaction between operators and devices is crucial. Since undergraduate teaching labs at public-funded research Universities typically (i) lack budget for commercial, user-friendly continuous flow reactors and (ii) do not teach synthetic chemists how to program or interact with reactors, there is a disparity between the skills undergraduates are equipped with and the skills that future industries need. We report a teaching lab project where undergraduates assemble, program and execute a continuous flow photoreactor to realize a multigram-scale photoredox catalyzed oxidation reaction. A palladium-free synthetic access to the starting material was described to further cut costs. Not only does this exercise introduce useful skills in reactor design, programming and wet chemistry (both photochemical and thermal, both batch and flow), it also accommodates both the typical budget and afternoon timeslot (2-3 h) of a teaching lab and can be followed by thin-layer chromatography/color changes without necessarily requiring access to NMR facilities. [ABSTRACT FROM AUTHOR]

Recently demonstrated as a novel reaction screening technology, the stop-flow micro-tubing (SFMT) reactors amalgamate features from continuous micro-flow and conventional batch reactors, resulting in a more logical and rigorous synthesis approach. When compared to traditional batch reactors, SFMT provides a safer and more efficient alternative, particularly suitable for chemical reactions under drastic conditions. The incorporation of commercially available transparent micro-tubing into SFMT makes it an excellent choice for light-mediated reactions, ensuring more uniform exposure to light. And SFMT stands apart from continuous-flow reactors by offering a notably convenient screening approach that is unrestricted by residence time and reactor size, while also effectively eradicating the risk of cross-contamination. The successful reactions developed within the SFMT reactor can be easily translated to continuous-flow synthesis for large-scale production. Overall, the SFMT reactor system exhibits similarities to continuous-flow reactors while surpassing batch reactors, especially for reactions involving gas reagents and/or requiring light illumination. This review aims to provide a comprehensive survey of the synthetic application of SFMT. [ABSTRACT FROM AUTHOR]

We investigated the flow acetalization of aldehydes and THP protection of alcohols using sulfonic acid-functionalized silica gel having hydroxy moiety (HO-SAS) as the solid acid catalyst. The reaction both aliphatic and aromatic aldehydes reacted with methanol within 5 min of residence time to give acetalization product in good to excellent yield. THP protection of primary, secondary, and tertiary alcohols proceeded well to the corresponding products. Both reactions did not require a neutralization process. Scalable syntheses were also achieved with continuous operation. The deprotection reactions were also effective using HO-SAS packed flow reactors. [ABSTRACT FROM AUTHOR]

This study introduces aptamer-functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles for adenosine triphosphate (ATP) detection where the POSS nanoparticles were synthesized in a one-step, continuous flow microfluidic reactor utilizing thermal polymerization. A microemulsion containing POSS monomers was generated in the microfluidic reactor which was designed to prevent clogging by using a continuous oil flow around the emulsion during thermal polymerization. Surfaces of POSS nanoparticles were biomimetically modified by polydopamine. The aptamer sequence for ATP was successfully attached to POSS nanoparticles. The aptamer-modified POSS nanoparticles were tested for affinity-based biosensor applications using ATP as a model molecule. The nanoparticles were able to capture ATP molecules successfully with an affinity constant of 46.5 μ M. Based on this result, it was shown, for the first time, that microfluidic synthesis of POSS nanoparticles can be utilized in designing aptamer-functionalized nanosystems for biosensor applications. The integration of POSS in biosensing technologies not only exemplifies the versatility and efficacy of these nanoparticles but also marks a significant contribution to the field of biorecognition and sample preparation. [ABSTRACT FROM AUTHOR]

Alpha alumina (α‐Al2O3) catalysts synthesized by ball milling are investigated in the dehydration of methanol to dimethyl ether (DME). The activity and stability of the catalysts were studied in a fixed‐bed continuous‐flow reactor setup. The effect of water vapor in the feed was studied as well. Among different alumina polymorphs studied, γ‐ alumina has been known to be the most effective for this reaction; however, the high surface area α‐Al2O3, which had been synthesized by ball milling, resulted in a comparable rate of methanol conversion, while it revealed a more stable performance under the influence of water vapor. The surface area, the number, and the nature of the acidic sites were found to be relevant parameters for the conversion of methanol to DME. The selectivity was as high as 99 % towards DME. [ABSTRACT FROM AUTHOR]

The catalytic properties of packed bed reactors filled with Y(OTf)3 immobilised onto functionalised silica have been tested in the Michael addition of indoles to benzylidene malonates under flow conditions, providing improved productivity over the batch conditions, a greater ease of recovery of the final products and a prolonged life of the catalyst. Noteworthy, the same catalytic reactor, after being used for five days, was employed to perform a different reaction, a stereoselective Diels Alder cycloaddition in flow, with a 24 times higher productivity compared to the in‐batch reaction. [ABSTRACT FROM AUTHOR]

Multiphasic reaction of bicarbonate hydrogenation to form formate using homogeneous Ru PNP pincer catalyst in a continuous flow tubular reactor is reported. The reaction system consists of three phases. Catalyst is dissolved in toluene while potassium bicarbonate is dissolved in water. The significance of efficient mixing among the organic phase, aqueous phase and gaseous hydrogen to improve hydrogenation reaction by using different inert packing materials is studied by operando visualization and also quantitatively discussed. The bicarbonate conversion of up to 67% is achieved after optimization of important reaction and reactor parameters. The designed reactor setup comprised of effective recycling system that recycles the catalyst with >99% activity. [ABSTRACT FROM AUTHOR]

Metal oxide (MexOy) nanomaterials are used as catalysts and/or sorbents in processes taking place in supercritical water (scH2O), which is the "green" solvent needed to obtain energy-relevant products. Their properties are significantly influenced by the synthesis method used to prepare active MexOy. In addition, the use of supported MexOy nanoparticles is more practical and cost-effective in terms of their performance maintenance. Within this context, the present study reports on the preparation of carbon-supported ZnO and CuO composites using an innovative scH2O impregnation method. Metal oxides were impregnated on a carbon (C) support using a continuous-flow tubular reactor. The results show that impregnation in scH2O is a promising approach for the preparation of ZnO/C and CuO/C composite materials. This one-step synthesis method, in a continuous flow, uses neither a seed layer nor a mineralizer, and it needs substantially lower preparation times than conventional impregnation methods. [ABSTRACT FROM AUTHOR]