Continuous Production Process Research Articles

Advanced microfluidic techniques for in situ PLGA microparticle formation: A dynamic solvent extraction approach

Microencapsulation processes often use the "solvent extraction/evaporation" technique, which involves (i) dissolving a polymer in an organic solvent (optionally with a bioactive component), (ii) forming microdroplets, (iii) removing the solvent, and finally (iv) harvesting and drying the particles ex situ. These last two steps lack control over the solidification processes, which adversely affects the morphology and size distribution of the final microparticles. In this study, we present a continuous production process for solid PLGA microparticles within a microfluidic chip, covering droplet formation, solvent extraction, and solidification. This method offers the advantage of enhanced control over the solidification process within a closed system, leading to morphologically uniform particles. The setup includes a co-axial junction integrated into a chip with an 80 cm long serpentine channel. We generated droplets with various PLGA/ethyl acetate concentrations and tracked their shrinkage until solidification. Results showed that all droplets underwent identical shrinkage processes with consistent rates, velocity profiles, and sizes. The shrinkage rate was linear and unaffected by PLGA concentration, which only influenced final particle size.To demonstrate our setup's advantages, we compared it with the conventional off-chip method, where droplets shrink in a beaker. Off-chip shrinkage was non-linear and inconsistent, influenced by factors such as the number of surrounding droplets and production time. Droplets produced within a 10-s difference had solidification delays up to 250 s. In contrast, on-chip production was uniform, predictable, and 4–10 times faster. SEM imaging confirmed that on-chip particles were consistently spherical with a rough, wrinkled surface, unlike the irregular, bumpy off-chip particles.In summary, on-chip production and shrinkage of PLGA particles is faster and produces more uniformly shaped particles compared to off-chip methods. This study suggests that on-chip production could significantly enhance the efficiency and quality of drug-loaded microparticles, particularly for drug delivery applications.

Design, simulation and investigation of the tri-generation process of fresh water, power and biogas using solar thermal energy and sewage sludge

To address the high demand for energy and fresh water, the effect of global warming and pollution generated by fossil fuels consumption needs to be minimized and replaced with alternative renewable energy. Hybrid renewable energy systems using solar energy and biomass will become more crucial. In this study a new design for continuous production process of power, biogas and fresh water is proposed. The challenge of the present research is to use different sources for energy production from renewable resources simultaneously including solar and biomass to produce power, fuel and fresh water, using 4-stage Multi Effect Distillation (MED) for desalination of seawater. To cope with constant and stable energy production required for renewable solar power plants at night, due to lack of sunlight, co-consumption of hybrid solar and biomass feedstocks is considered in this paper. The associated challenge is discussed by the assessments of Solar Heat transfer fluid (SHTF), Sewage sludge flowrates, biogas production, output waste stream of gasification reactor, power and fresh water production using ASPEN Plus software. The sensitivity analysis was performed to demonstrate the viability of the designed process and the resulting products. The gasification process produced 76.8586 tonh syngas (CO and H2). Also, 34.547 MW of power with about 783 m3h of fresh water were produced with the overall exergy efficiency of 35.51 %, 52.260 MW exergy destruction and desalination efficiency of 52 %. Only 25 MW of solar power were necessary due to proper energy recovery throughout the entire process. The productivity of fresh water production was 50 %. 38908 m2 of Parabolic trough collector (PTC) was needed to supply required solar energy during day light hours. It was revealed that the hybridization of solar & biomass energy resources for producing power, fresh water, and biogas could be a sustainable approach to cope with the increasing demand for fresh water, electricity, and fuel.

Novel low-temperature continuous phase-transition extraction process for efficient peanut oil production

Novel low-temperature continuous phase-transition extraction process for efficient peanut oil production

Improving efficiency and quality of operational industrial production assets information management in customer–vendor interaction

Industrial assets management has a key role in ensuring continuity of industrial production via purchasing, warehousing and maintenance of devices and spare parts used in manufacturing, but it suffers from data and information accessibility, completeness, consistency, interoperability, and timeliness challenges in the customer - equipment vendors interaction and information sharing. Current practices in devices and spare parts purchasing, warehousing and maintenance include a lot of manual information search, validation and update work done at the manufacturing companies to maintain high quality master data records for the production assets management. This article addresses the challenge of improving efficiency and quality of operational production assets information management in industry customer company interaction with their production equipment vendors, with a design science research approach. The research was executed in collaboration between research organizations, forest industry companies, industrial production equipment vendors and information technology (IT) companies on two parallel and complementary research tracks, which are described with their key research results. The contributions are an ex-ante evaluated digital marketplace concept with preliminary requirements, and an ex-post evaluated semi-automated master data harmonization tool, as artefacts for improving efficiency and quality of production assets information management in industrial customer–vendors interaction. As theoretical contribution, the article provides a synthesis of the research results in the framework of information systems (IS) design theory as a nascent and novel design theory on designing IS artifacts for improving efficiency and quality of production assets information management, both in single industrial customer company and ecosystem settings. The contributions provide a starting point for further research and development of a digital marketplace for improving production assets information management in industrial customers – vendors interaction, potentially also applicable for similar ecosystems in other continuous production process -based manufacturing industries.

Implementing multiblock techniques in a full-scale plant scenario: On-line prediction of quality parameters in a continuous process for different acrylonitrile butadiene styrene (ABS) products

BackgroundThe study explores the challenges of handling multiblock data of different natures (process and NIR sensors) for on-line quality prediction in a full-scale plant scenario, namely a plant operating in continuous on an industrial scale and producing different grade Acrylonitrile Butadiene Styrene (ABS) products. This environment is an ideal scenario to evaluate the use of multiblock data analysis methods, which can enhance data interpretation, visualization, and predictive performances. In particular, a novel multiblock extension of Locally Weighted PLS has been proposed by the authors, namely Locally Weighted Multiblock Partial Least Squares (LW-MB-PLS). Response-Oriented Sequential Alternation (ROSA) has also been employed to evaluate the diverse block relevance for the prediction of two quality parameters associated with the polymer. Data are split in blocks both according to sensor type and different plant sections, and different models have been built by incremental addition of data blocks to evaluate if early estimation of product quality is feasible. ResultsROSA method showed promising predictive performance for both quality parameters, highlighting the most influential plant sections through the selection of data blocks. The results suggested that both early and late-stage sensors play crucial roles in predicting product quality. A reasonable estimation of quality parameters before production completion has been achieved. On the other hand, the proposed LW-MB-PLS, while comparable in predictive performances, allowed reducing systematic prediction errors for specific products. SignificanceThis study contributes valuable insights for continuous production processes, aiding plant operators and paving the way for advancements in online quality prediction and control. Furthermore, it is implemented as a locally weighted extension of MB-PLS.

Selective H2 production from plastic waste through pyrolysis and in-line oxidative steam reforming

This study deals with the proposal of pyrolysis and in-line oxidative steam reforming (P-OSR) for plastic waste valorization and assesses the potential of this strategy for the selective production of H2. Overall, the study aims at progressing towards the fine-tuning of the pyrolysis-reforming technology by co-feeding O2. Thus, a multi-point O2 injection system has been developed to ensure a suitable O2 distribution in the reforming reactor and avoid the formation of hot spots, as they may cause catalyst deactivation by metal sintering. Moreover, as O2 is directly supplied into the catalytic bed, pre-combustion of the volatile stream before contacting the catalyst is avoided and in-situ coke combustion is promoted. The P-OSR of HDPE was carried out in a two-step reaction system, which combines CSBR (conical spouted bed reactor) and FBR (fluidized bed reactor) technologies. The experiments were conducted in continuous mode and the influence of the main process conditions at zero time on stream was analyzed. Thus, the effect of reforming temperature was studied in the 550–750 °C range, that of the space time from 3.12 to 15.62 gcat min gHDPE−1, steam to plastic (S/P) ratio between 2 and 5 and equivalence ratio (ER) from 0 to 0.3. Under the optimum conditions (700 °C, S/P of 3, 12.5 gcat min gHDPE−1 and ER of 0.2), a H2 production of 25.0 wt% was obtained, which is only 28.6 % lower than that obtained in the conventional pyrolysis-steam reforming (P-SR) process. The results obtained confirm the potential of continuous P-OSR process for the selective production of H2.

NMR in Battery Anode Slurries with a V-Shaped Sensor.

Inline analytics in industrial processes reduce operating costs and production rejection. Dedicated sensors enable inline process monitoring and control tailored to the application of interest. Nuclear Magnetic Resonance is a well-known analytical technique but needs adapting for low-cost, reliable and robust process monitoring. A V-shaped low-field NMR sensor was developed for inline process monitoring and allows non-destructive and non-invasive measurements of materials, for example in a pipe. In this paper, the industrial application is specifically devoted to the quality control of anode slurries in battery production. The characterization of anode slurries was performed with the sensor to determine chemical composition and detect gas inclusions. Additionally, flow properties play an important role in continuous production processes. Therefore, the in- and outflow effects were investigated with the V-shaped NMR sensor as a basis for the future determination of slurry flow fields.

Quaternary phosphonium-polyamide membranes for efficient lithium extraction from brine sources

Lithium extraction from brine sources such as salt lakes, seawater, and produced water from oil/gas fields is garnering increasing interests from the academic and industrial sectors due to its cost-effectiveness and reduced environmental impact. A critical technological challenge is the efficient separation of Mg2+ and Li+ ions. Many researchers have reported the preparation of positively charged nanofiltration membranes with quaternary ammonium groups, yet investigations about quaternary phosphonium groups are scarce. In this work, positively charged nanofiltration membranes were prepared utilizing polyethyleneimine as the aqueous phase monomer, trimesoyl chloride as the organic phase monomer, and 3-bromopropyl triphenyl phosphonium bromide as the functionalizing monomer. The TFC-P+ membranes, enriched with a high density of quaternary phosphonium groups and an enhanced Donnan effect, achieve a MgCl2 rejection of 98.9 %, a Mg2+/Li+ selectivity of 81.6, and a water flux of 50 LMH under 0.5 MPa. The membranes possess an enhanced comprehensive separation capability that exceeds that of the majority of nanofiltration membranes documented in scholarly articles. Additionally, the membranes exhibit outstanding anti-fouling and anti-bacterial characteristics, essential for their industrial applications. The preparation method proposed herein is simple and conducive to continuous production processes. In light of the abundant produced water reserves from oil and gas extraction, future work will focus on pilot-scale lithium extraction experiments.

Optimal design of a local renewable electricity supply system for power-intensive production processes with demand response

This work studies synergies arising from combining industrial demand response and local renewable electricity supply. To this end, we optimize the design of a local electricity generation and storage system with an integrated demand response scheduling of a continuous power-intensive production process in a multi-stage problem. We optimize both total annualized cost and global warming impact and consider local photovoltaic and wind electricity generation, an electric battery, and electricity trading on day-ahead and intraday market. We find that installing a battery can reduce emissions and enable large trading volumes on the electricity markets, but significantly increases cost. Economically and ecologically-optimal operation of the process and battery are driven primarily by the electricity price and grid emission factor, respectively, rather than locally generated electricity. A parameter study reveals that cost savings from the local system and flexibilizing the process behave almost additively.

Continuous CF/PA6 Composite Aircraft Window Frame Manufactured via a Novel Winding Compression Process.

Using fiber-reinforced polymer composite to replace metal in window frames has become a trend in aircraft manufacturing to achieve structural weight reduction. This study proposes an innovative winding compression molding process for continuous production of aircraft window frames using continuous carbon fiber-reinforced polyamide 6 thermoplastic composite filaments (CF/PA6). Through process parameter optimization, the production cycle of CF/PA6 composite window frames was controlled within 5 min, with an ultra-low porosity of 0.69%, meeting aviation application standards. Combining mechanical property experimental tests and finite element analysis, the mechanical performance of window frames made from three different materials was compared and evaluated. In the hoop direction, the mechanical performance of the continuous CF/PA6 thermoplastic window frames were significantly higher than that of chopped CF/epoxy compression molding window frames and aluminum alloy window frames. In the radial direction, the maximum strain occurred at the corner with the highest curvature of the frame due to the absence of fiber reinforcement, resulting in weak pure interlayer shear. Nevertheless, the thermoplastic CF/PA6 winding compression molded window frame still exhibited a high resistance to crack propagation and damage, as evidenced by the absence of any detectable sound of microdamage during testing with a 9000 N load. It is believed that achieving a further-balanced design of hoop-radial performance by appropriately introducing radial ply reinforcement can lead to a significant weight reduction goal in the window frame. The findings in this study provide an innovative process reference that can be universally applicable to high-speed and near-net-shape manufacturing without material waste of continuous fiber-reinforced thermoplastic composite products.

Intensified Continuous Flow Process for the Scalable Production of Bio-Based Glycerol Carbonate.

A subtle combination of fundamental and applied organic chemistry toward process intensification is demonstrated for the large-scale production of bio-based glycerol carbonate under flow conditions. The direct carbonation of bio-based glycidol with CO2 is successfully carried out under intensified flow conditions, with Barton's base as a potent homogeneous organocatalyst. Process metrics for the CO2 coupling step (for the upstream production, output: 3.6 kg day-1 , Space Time Yield (STY): 2.7 kg h-1 L-1 , Environmental factor (E-factor): 4.7) outclass previous reports. High conversion and selectivity are achieved in less than 30 s of residence time at pilot scale with a stoichiometric amount of CO2 . Supporting DFT computations reveal the unique features of the mechanism in presence of Brønsted bases.

Intensified Continuous Flow Process for the Scalable Production of Bio‐Based Glycerol Carbonate**

AbstractA subtle combination of fundamental and applied organic chemistry toward process intensification is demonstrated for the large‐scale production of bio‐based glycerol carbonate under flow conditions. The direct carbonation of bio‐based glycidol with CO2 is successfully carried out under intensified flow conditions, with Barton's base as a potent homogeneous organocatalyst. Process metrics for the CO2 coupling step (for the upstream production, output: 3.6 kg day−1, Space Time Yield (STY): 2.7 kg h−1 L−1, Environmental factor (E‐factor): 4.7) outclass previous reports. High conversion and selectivity are achieved in less than 30 s of residence time at pilot scale with a stoichiometric amount of CO2. Supporting DFT computations reveal the unique features of the mechanism in presence of Brønsted bases.

Molecular dynamics simulation and experimental verification of influence of crosslinking reaction process parameters on oxygen permeability of PDMS membranes

Sufficient oxygen permeability of the substrate is the key to ensuring the reliability of the Continuous Liquid Interface Production process. Polydimethylsiloxane (PDMS), as a cost-effective material with good gas permeability, holds potential for applications as oxygen-permeable windows in constrained substrates. Therefore, it is of great significance to investigate how to enhance the oxygen permeability of PDMS. In this study, the program code for the crosslinking reaction between the prepolymer and curing agent was developed. Molecular dynamics simulations were employed to investigate the effects of the process parameters on the diffusion coefficient of oxygen. Validation experiments were conducted by measuring the oxygen permeability of the substrate. The research findings reveal that process parameters, including crosslinking time, crosslinking temperature, and the mass ratio of prepolymers to curing agents, influence the diffusion coefficient of oxygen in PDMS membranes. Increasing the crosslinking time leads to an increase in the number of crosslinking points, hindering polymer chain mobility and limiting the increase in free volume, thereby decreasing the oxygen diffusion coefficient. An optimal crosslinking temperature of 348 K enhances the probability of jump channel formation between cavities, resulting in the maximum oxygen diffusion coefficient. The oxygen diffusion coefficient of PDMS membranes increases with rising mass ratio.

Pressure Sensors: Working Principles of Static and Dynamic Calibration.

This paper starts with an overview of the main principles used for pressure measurements, focusing on their usage in industrial applications' domains. Then, the importance of calibration procedures, namely, static and dynamic calibration of pressure sensors, is analyzed. Regarding calibration, it is important to note that there are several applications where the pressure signals to be measured can have large variations in short periods of time. In industrial applications, particularly in continuous production processes, generally, dynamic pressure measurements are less common; however, they are still required in several cases, such as control loops that are very sensitive to pressure variations, even if the frequencies of those variations are in the range of a few tens of hertz, or even lower. The last part of the paper presents the hardware and software of a flexible and low-cost static and dynamic pressure calibrator that also presents the capability to generate arbitrary waveform pressure signals for calibration and testing purposes. The proposed calibrator also includes the following advantages: remote pressure sensing capabilities that can be used to minimize calibration errors, such as those associated with capillary effects and pressure leakages; portability; and low cost. The paper ends with some experimental results obtained with the proposed calibrator.

End-to-End Continuous Small-Scale Drug Substance Manufacturing: From a Continuous In Situ Nucleator to Free-Flowing Crystalline Particles

In the evolving landscape of pharmaceutical manufacturing, a comprehensive continuous production process is being crafted for the small-scale production of active pharmaceutical ingredients. This study focuses on continuous crystallization with separate nucleation and crystal growth units, as well as continuous downstream processing, encompassing filtration, washing, and drying until the formation of free-flowing particles. We introduce a novel continuous nucleator designed based on solubility data and produced via 3D printing, enabling the fast and precise small-scale manufacturing of a nucleator meeting the requirements for nucleation and further growth processes. The nucleator is evaluated with regard to its suitability for continuous long-term operation across various coupled crystallizers. As a practical application example, it is connected to a slug flow crystallizer to enable high-quality continuous crystallization. Additionally, the full integration of downstream processes using a continuous vacuum screw filter to achieve free-flowing product particles is realized. Even under non-optimized process conditions, with the help of the in situ generation of nuclei, free-flowing product particles are successfully obtained. This is particularly useful during drug development when no material is available for seed addition and to quickly obtain products for further characterization.

Proper Material Tracking for a Continuous Aluminum Production Process

Proper Material Tracking for a Continuous Aluminum Production Process

Pore structure regulation and continuous preparation with VNIPS process of membranes for bioseparation

Ultrafiltration technology has found widespread application in bioprocessing, particularly in protein concentration and buffer exchange for downstream processes. The demand for this technology has spurred research efforts to develop excellent membrane structures with superior separation functionality. However, challenges persist in transitioning laboratory research to industrial-scale continuous production processes while simultaneously optimizing membrane structure and performance through a single fabrication method. Thus, there is an urgent need for pilot-scale membrane preparation to improve membrane morphology and separation efficiency while ensuring scalability. This study investigates a continuous membrane fabrication method, systematically exploring the influence of different additives and vapor-assisted nonsolvent induced phase separation (VNIPS) on the structure and performance of polyethersulfone (PES) membranes. Evaluations of PES membranes with distinct structures were performed, employing flux decline, resistance analysis, and alkali resistance tests to distinguish their performance and bioseparation capabilities. The results showed that good sponge-like pore structure was obtained by VNIPS process, which realized the synergistic optimization of permeation and retention properties. Besides, the sponge-like porous structure membranes prepared by amphiphilic copolymer additives are more suitable for bioseparation.

Physical and Numerical Simulation Study on Structure Optimization of the Inner Wall of Submerged Entry Nozzle for Continuous Casting of Molten Steel

The submerged entry nozzle (SEN) plays an important role in the continuous casting production process. It is a cast refractory pipe fitting installed in the lower part of the tundish and inserted below the molten steel level of the mold. It not only affects the speed of molten steel flow, but is also prone to nodules and affects production. In the present work, the flow behavior of molten steel in a traditional nozzle and that in a new type of nozzle whose inner wall was distributed with arrays of hemispherical crowns were studied by means of both physical simulation (using a water model) and numerical simulation (using ANSYS CFX) based on the prototype of a production continuous casting slab mold. Both experimental and numerical simulation results show that, compared with the traditional nozzle, the impact depth generated by the new-type nozzle in the mold is reduced by 21.06–26.03 cm, the impact angle is reduced by 14–17 degrees, and swirl flow was generated inside the new-type nozzle, which not only improves the flow characteristics inside the submerged entry nozzle and changes the dead zone size in the submerged entry nozzle, but also improves the velocity distribution at the outlet of the nozzle and minimizes the possibility of nodulation. In addition, in contrast to the traditional nozzle that generates flat body-shaped jets of molten steel flow, the new-type nozzle produces baseball glove-shaped jets that penetrate shallower into the molten steel bath in the mold, which significantly reduces the outlet velocity and is conducive to the floating of inclusions.

Single-Step Biofabrication of In Situ Spheroid-Forming Compartmentalized Hydrogel for Clinical-Sized Cartilage Tissue Formation.

3D cellular spheroids offer more biomimetic microenvironments than conventional 2D cell culture technologies, which has proven value for many tissue engineering applications. Despite beneficiary effects of 3D cell culture, clinical translation of spheroid tissue engineering is challenged by limited scalability of current spheroid formation methods. Although recent adoption of droplet microfluidics can provide a continuous production process, use of oils and surfactants, generally low throughput, and requirement of additional biofabrication steps hinder clinical translation of spheroid culture. Here, the use of clean (e.g., oil-free and surfactant-free), ultra-high throughput (e.g., 8.5mL min-1 , 10 000 spheroids s-1 ), single-step, in-air microfluidic biofabrication of spheroid forming compartmentalized hydrogels is reported. This novel technique can reliably produce 1D fibers, 2D planes, and 3D volumescompartmentalized hydrogel constructs, which each allows for distinct (an)isotropic orientation of hollow spheroid-forming compartments. Spheroids produced within ink-jet bioprinted compartmentalized hydrogels outperform 2D cell cultures in terms of chondrogenic behavior. Moreover, the cellular spheroids can be harvested from compartmentalized hydrogels and used to build shape-stable centimeter-sized biomaterial-free living tissues in a bottom-up manner. Consequently, it is anticipated that in-air microfluidic production of spheroid-forming compartmentalized hydrogels can advance production and use of cellular spheroids for various biomedical applications.

Kilogram-scale production of high purity 2,5-furandicarboxylic acid via sustainable leap in continuous electrochemical oxidation of 5-hydroxymethylfurfural

Electrochemical oxidation of 5-hydroxymethylfurfural (HMFOR) stands out as an efficient and sustainable approach for 2,5-furandicarboxylic acid (FDCA) production. However, despite numerous catalyst advancements, the industrial adoption of this process faces significant challenges, stemming from limitations in scalability and high device costs. To address this gap, we developed a scalable HMFOR process for continuous FDCA production. Key parameters such as electrolyte concentration, anodic and cathodic catalysts, types of sparge gas, and current density were found to be critical to the yield and quality of the isolated FDCA products. NiFeOOH anode and Pt cathode operated at 33.3 mA cm−2 in 0.33 M KOH and O2 environment were chosen as they provided the fastest oxidation kinetic and minimized HMF degradation rate, hence producing FDCA with high yield and purity. Using the optimal conditions identified in a milligram-scale batch reactor, we constructed a 2-liter CSTR with a novel electrode design accommodating 100 A of current. This process achieved an unprecedented FDCA production rate of ∼2 kg per day and space–time yields of up to 295 μmol h−1 cm−2, along with exceptional stability for 48 h. The isolated FDCA demonstrated comparable purity and color to commercial products. This simple and robust continuous reactor design can be applied to other electrochemical biomass valorization processes, potentially replacing conventional electrolyzers.