Counter-current Mode Research Articles

Simulation of a Heat Transfer Mechanism in a Shell and Tube Coil Heat Exchanger

Statement of the problem. The mechanism of heat exchange between counterflow circuits in a shell-and-tube coil heat exchanger, inside which heating and heated coolants flow, is discussed. It is required to build computer models of the movement of coolants in different operating conditions, to simulate the mechanism of heat exchange in the countercurrent mode of movement of coolants in a shell-and-tube coil heat exchanger. This problem was solved in the Solidworks Flow Simulation software package. Results. A mathematical model of the heat exchange process in a shell-and-tube coil heat exchanger was obtained with visualization of the mechanisms of coolant movement inside the heating and heated circuits. Conclusions. Based on the simulation results, a comparison was made of various computer models of the apparatus obtained. The optimal design has been determined.

Conversion of Lithium Chloride into Lithium Hydroxide Using a Two-Step Solvent Extraction Process in an Agitated Kühni Column

A significant consequence of the green transition is the growing demand of lithium-ion batteries (LIBs), as they are essential for electrical vehicles. In turn, the demand for the raw materials that are needed to produce LIBs is increasing. A common LIB cathode type for electrical cars is lithium nickel manganese cobalt oxide (NMC). Since cobalt is currently considered as a critical raw material, nickel-rich NMC cathodes are now designed with lower cobalt contents. The synthesis of these new NMC types requires LiOH instead of Li2CO3, which was used for Co-richer NMC materials in the past. Most production routes of LiOH start from Li2CO3 or Li2SO4. However, LiCl could also be a potential precursor for LiOH, as it could be obtained from various lithium sources. A two-step solvent extraction process (SX) was developed for direct conversion of LiCl into LiOH, using a phenol (butylhydroxytoluene or BHT) and a mixture of quaternary ammonium chlorides (Aliquat 336) in an aliphatic diluent (Shellsol D70) as the solvent. The SX process was validated in counter-current mode using a rotary agitated Kühni extraction column. The use of a column instead of mixer-settlers reduced the CO2 uptake by the final product (LiOH), which prevented the partial conversion of LiOH to Li2CO3. A total of 75 L of LiCl feed solution was processed in the Kühni column to obtain a solution of LiOH with a final purity of more than 99.95%, at a yield of 96%.Graphical

Mitigating Joule heating in smart nanochannels: Evaluating the efficacy of AC vs. DC fields

This study delves into the profound implications of different electric field types, namely DC and AC with a sinusoidal waveform, on ion transport within intelligent soft nanochannels, aiming to mitigate Joule heating effects. The investigation considers temperature- and concentration-dependent properties and explores their impact on ionic selectivity, rectification factor, Joule heating, and viscosity dissipation in conical soft nanochannels. Operating in both co-current and counter-current modes, the study accounts for the nanochannel's coating with a dense and strongly negatively charged polyelectrolyte layer, addressing the ionic partitioning effect. Numerically solving the Poisson-Nernst-Planck, Navier-Stokes, and energy equations, the study reveals a significant alignment of Joule heating and viscosity dissipation with ionic current, emphasizing the influence of concentration and temperature ratios. Notably, the bidirectional AC field demonstrates a remarkable 85.51% and 71.72% reduction in Joule heating in co-current and counter-current modes, respectively, compared to DC. These findings highlight the significant impact of the AC field on thermal dynamics within nanochannels. In summary, our study offers essential insights into optimizing nanofluidic systems by effectively balancing ion transport efficiency and thermal effects across various electrical field scenarios. These findings directly address the critical challenge of managing Joule heating in intelligent nanochannels, which is essential for enhancing the performance of lab-on-a-chip devices in sensitive biomedical applications.

Two Phase Bubble Columns: the Determinants of the Flow Regime Transitions

The fluid dynamics in large-diameter bubble columns can be described by an analytical relation between two global flow parameters, the drift flux and the gas holdup. This relation, named bubble column operating curve, builds on five flow regime transitions. In order to determine the variables influencing the flow regime transitions, a statistical approach was derived by coupling: (1) the ordinary least squares method (OLS) to determine the relationship between the variables, (2) the variance inflation factor (VIF) to check for multicollinearity issues, and (3) the least absolute shrinkage and selection operator (LASSO), to select suitable variables. It was found that the geometrical characteristics of the sparger strongly influence the flow regime transitions, and uniform aeration is essential for all the regimes to exist. Increasing the superficial liquid velocity in the counter-current mode destabilises the mono-dispersed and poly-dispersed homogeneous flow regimes. As for the aspect ratio, an increase in the column aspect ratio slightly destabilises the existing flow regimes. The statistical method identifies viscosity as the only significative variable concerning the liquid phase properties.

Hydrometallurgical processing of molybdenum middlings from Shatyrkul-Zhaysan cluster ore

This research investigates the hydrometallurgical processing of molybdenum middlings extracted from copper-molybdenum ore in the Shatyrkul-Zhaysan cluster in Kazakhstan. A molybdenum intermediate obtained after selective flotation of the copper-molybdenum concentrate was used, with a recovery of 0.07%, a molybdenum content of 22.23% and an extraction of 74.91%. The mineralogical analysis shows molybdenite and chalcopyrite as the main minerals. In experiments, atmospheric leaching with nitric acid in single-stage and two-stage countercurrent processes was investigated to optimize molybdenum extraction and reduce acid consumption. The optimum conditions obtained were: 300 g/L nitric acid, 100 g/L sulfuric acid, 90?C temperature and 2 hours leaching time in the single-stage leaching, which extracted 98.8% molybdenum. The two-stage leaching under optimized conditions allows the extraction of 94.3% molybdenum in solutions with lower residual acidity (0.89 g-eq/L) and redox potential (550 mV) without reducing the extraction of valuable component. Molybdenum extraction reaches 94.3% in the subsequent solvent extraction stage from two-stage leaching solutions. The final product, calcium molybdate with a molybdenum content of 46.83%, meets commercial grade specifications. This research demonstrates an effective process for hydrometallurgical production of commercial grade calcium molybdenite from copper-molybdenum ore, with high molybdenum recovery, reduced acid consumption through two-stage leaching, and minimal hazardous discharges.

The critical role of fracture flow on two-phase matrix–fracture transfer mechanisms

We analyze the dynamics of imbibition in a fractured medium using the Direct Numerical Simulation of the Navier–Stokes equations. Pore geometries with homogeneous and heterogeneous pore distributions at the matrix and fracture interface are considered in this study. We evaluate the role of critical factors such as wettability, viscosity ratio, injection rate, and the magnitude of the interfacial tension on the pore-scale dynamic of mass exchange between matrix and fracture for 2D geometries consisting of a complex pore-geometry and a single fracture. Two different regimes are identified during the injection of wetting fluid through the fracture into the domain saturated with a non-wetting fluid: (1) co-operative (co-current) imbibition before the wetting phase breakthrough and, (2) counter-current imbibition follows afterwards. For the studied 2D geometries, the displacement efficiency is higher in the co-operative imbibition, while the counter-current imbibition occurs at a slow pace. Lower injection rates in the fracture are in favor of improving displacement efficiency in the porous matrix. Higher wettability and interfacial tension help the wetting fluid to penetrate further into the matrix and improve the displacement rate for both co-operative and counter-current modes of displacement.

Design of a liquid organic hydrogen carrier (LOHC) dehydrogenation system integrated with the concentrated solar power (CSP) plant

The present study combines the perhydro dibenzyl toluene (PDBT) dehydrogenation reactor with the heat supplied by the heat transfer fluid, namely diphenyl ether (DPE), from the concentrated solar power (CSP) plant. The flowsheet has been simulated using the combination of DWSim v 6.5.2 and Python.NET. The dehydrogenation reactor is operated at a feed temperature between 563 K and 633 K and a pressure of 2 atm. The diphenyl ether is supplied to heat the reactor at the inlet temperature of the thermic fluid to the jacket at 663 K and 673 K. The process has been simulated to produce 10 Nm3/hr of industrial-grade hydrogen. The variation of the feed temperature, the temperature of the thermic fluid in the jacket and PDBT conversion across the catalyst weight with respect to the inlet feed temperature, the inlet temperature of the thermic fluid to the jacket and flow direction (co-current and counter-current) in the jacketed packed bed reactor (PBR) has been studied. Similarly, the weight of the catalyst required for the reactor, the area needed for the heat exchangers, and the concentrated solar power (CSP) plant have also been discussed. Cost analysis of the catalyst, concentrated solar power plant, the total annual cost of the process and the cost per kilogram of hydrogen based on the inlet feed temperature, the inlet temperature of the thermic fluid to the jacket, and the direction of the flow in the jacketed PBR have been considered. The lowest total annual cost of the process is found at the counter-current mode of operation, with the inlet feed temperature of 623 K and the inlet temperature of the thermic fluid to the jacket at 673 K.

Development of an Inline Tube-in-Tube Solvent Exchanger for Continuous-Flow Swap from High- to Low-Boiling Solvent

Solvent swap from high- to low-boiling solvents still presents a huge challenge in the development of multistep continuous-flow processing. Herein, a miniaturized inline tube-in-tube solvent exchanger combining intensified convective mass transfer with droplet evaporation is presented. The design involves intimate contact between droplet and gas phases in countercurrent mode within a mesofluidic tube. Its solvent removal performance was evaluated by using pure solvents and binary mixtures. The results revealed that the commonly used solvents with low to medium boiling points (Tb < 100 °C) can be completely evaporated at room temperature without the need of heating. Significantly, high-boiling solvents can be efficiently removed at temperatures much lower than their boiling points. Its capacity for the separation of binary mixtures was corroborated by removing dichloromethane from a 50:50 mol % dichloromethane–dimethylformamide mixture and acetic acid from a 50:50 mol % p-nitroacetophenone–acetic acid mixture. A computational fluid dynamics (CFD) model based on the phase field approach was developed to quantitatively describe the droplet evaporation process, providing indepth evaporation dynamics and furthering our understanding on the concomitant phase change phenomenon. The comparison with other types of evaporators highlights its superior evaporative performance. To enable fast design and optimization of this type of evaporators, a correlation model was proposed to calculate the evaporation rate with good prediction performance. The usefulness of this device was demonstrated by performing a two-step continuous-flow synthesis of 4-aminoacetophenone. The combined experimental and CFD studies demonstrate that this tube-in-tube device can serve as a convenient and efficient tool for continuous solvent exchange, particularly from high- to low-boiling solvents, in continuous-flow synthesis.

Recovery of Lithium from Simulated Nanofiltration-Treated Seawater Desalination Brine Using Solvent Extraction and Selective Precipitation

ABSTRACT The world's seas and oceans contain vast amounts of lithium, but the low concentration hereof renders solvent extraction impractical for its recovery. By contrast, seawater desalination brine, after treatment by nanofiltration, contains a roughly tenfold greater concentration of lithium than raw seawater. Hence, lithium can be effectively recovered from such streams using solvent extaction. Compared with other techniques to sequester lithium from dilute solutions, solvent extraction offers the advantages of simple operations, robust and well-established technology and high recovery yields. Thus, we propose a solvent-extraction based process to recover lithium from seawater desalination brine, treated by nanofiltration. The first step comprises the removal of magnesium and calcium using methyltrioctylammonium neodecanoate in p-cymene. This is followed by a lithium extraction step using the extractants Mextral 54–100 and Cyanex 923 in Shellsol D70 diluent. The lithium extract is then scrubbed with water and stripped with hydrochloric acid. Subsequently, residual alkaline earth metals are removed with sodium hydroxide in ethanol and finally lithium is precipitated using sodium carbonate. The solvent extraction, scrubbing and stripping steps were demonstrated on mini-pilot scale in continuous countercurrent mode (in mixer-settlers), while the precipitation steps were demonstrated in batch. The process was found to have an overall yield of 74%, affording a lithium carbonate product with a purity of 97 wt%.

Red Fruit Juice Concentration by Osmotic Distillation: Optimization of Operating Conditions by Response Surface Methodology.

Osmotic distillation (OD) was implemented at laboratory scale to concentrate a red fruit juice produced from a blend of blood orange, prickly pear, and pomegranate juice. The raw juice was clarified by microfiltration and then concentrated by using an OD plant equipped with a hollow fiber membrane contactor. The clarified juice was recirculated on the shell side of the membrane module, while calcium chloride dehydrate solutions, used as extraction brine, were recirculated on the lumen side in a counter-current mode. The influence of different process parameters, such as brine concentration (20, 40, and 60% w/w), juice flow rate (0.3, 2.0, and 3.7 L min-1), and brine flow rate (0.3, 2.0, and 3.7 L min-1) on the performance of the OD process in terms of evaporation flux and increase in juice concentration, was investigated according to the response surface methodology (RSM). From the regression analysis, the evaporation flux and juice concentration rate were expressed with quadratic equations of juice and brine flow rates, as well as the brine concentration. The desirability function approach was applied to analyse the regression model equations in order to maximize the evaporation flux and juice concentration rate. The optimal operating conditions were found to be 3.32 L min-1 brine flow rate, 3.32 L min-1 juice flow rate, and an initial brine concentration of 60% w/w. Under these conditions, the average evaporation flux and the increase in the soluble solid content of the juice resulted in 0.41 kg m-2 h-1 and 12.0 °Brix, respectively. Experimental data on evaporation flux and juice concentration, obtained in optimized operating conditions, resulted in good agreement with the predicted values of the regression model.

Study on 3D Simulation Performance of Large‐Scale Proton Exchange Membrane Fuel Cell with Distribution Region

The majority of the current research examines fuel cell performance metrics using single channels or small‐area flow fields, but fails to take into consideration the actual shape of the flow field of modern proton exchange membrane fuel cell (PEMFC). The homogeneous distribution of reaction gas concentration and liquid water distribution is examined using 3D computational fluid dynamics simulation on a commercial large‐scale PEMFC with 113.92 cm2 reaction area and distribution region as the object. The results show that the gas distribution in the fluid flow is effectively optimized under the action of the distribution zone, and the maximum concentration error of anode is 4.87%, which is far less than that of cathode, and the higher the flow rate in the flow channel, the stronger the water removal ability; the effects of different working pressure and flow direction of reactant gas on gas concentration in catalytic layer and water content in proton exchange membrane are also studied. The results show that higher working pressure is beneficial to improve the performance of fuel cell, and countercurrent mode is better; finally, the influence of coolant is analyzed, and the results show that coolant can effectively reduce the internal temperature of the fuel cell, which is beneficial to improve the life of the fuel cell.

Development of an Integrated Continuous Manufacturing Process for the rVSV-Vectored SARS-CoV-2 Candidate Vaccine.

The administration of viral vectored vaccines remains one of the most effective ways to respond to the ongoing novel coronavirus disease 2019 (COVID-19) pandemic. However, pre-existing immunity to the viral vector hinders its potency, resulting in a limited choice of viral vectors. Moreover, the basic batch mode of manufacturing vectored vaccines does not allow one to cost-effectively meet the global demand for billions of doses per year. To date, the exposure of humans to VSV infection has been limited. Therefore, a recombinant vesicular stomatitis virus (rVSV), which expresses the spike protein of SARS-CoV-2, was selected as the vector. To determine the operating upstream process conditions for the most effective production of an rVSV-SARS-CoV-2 candidate vaccine, a set of critical process parameters was evaluated in an Ambr 250 modular system, whereas in the downstream process, a streamlined process that included DNase treatment, clarification, and a membrane-based anion exchange chromatography was developed. The design of the experiment was performed with the aim to obtain the optimal conditions for the chromatography step. Additionally, a continuous mode manufacturing process integrating upstream and downstream steps was evaluated. rVSV-SARS-CoV-2 was continuously harvested from the perfusion bioreactor and purified by membrane chromatography in three columns that were operated sequentially under a counter-current mode. Compared with the batch mode, the continuous mode of operation had a 2.55-fold increase in space-time yield and a reduction in the processing time by half. The integrated continuous manufacturing process provides a reference for the efficient production of other viral vectored vaccines.

Plasma levels of creatine, 2-aminobutyric acid, acetyl-carnitine and amino acids during fasting measured by counter-current electrophoresis in PAMAPTAC capillary

Determination of the minor nitrogen metabolites, creatine, 2-aminobutyric acid (2-AB), and acetyl-carnitine (Ac-carn), in human plasma is performed by capillary electrophoresis (CE) in a 6 % PAMAPTAC coated fused silica capillary. 6 % PAMAPTAC generates a stable electroosmotic flow (EOF) of 6.31 × 10−9 m2V−1s−1; and the nitrogen metabolites are separated in a counter-current mode, which increases electrophoretic resolution. Baseline separation of creatine, 2-AB, Ac-carn, and most proteinogenic amino acids is achieved in 8.5 M acetic acid (AcOH) at pH 1.37 as background electrolyte (BGE) at an effective capillary length of 14.4 cm with migration times ranging from 4.95 min for creatine to 5.43 min for Ac-carn. 20 μL of plasma is deproteinized with the addition of 60 μL of acetonitrile (ACN) and a 21.8 mm sample zone is injected into the capillary, which corresponds to 6.9 % of total and 15 % of effective capillary length. The zone is focused using a large volume sample stacking technique with LODs of 0.2–0.4 μM and LOQs of 0.8–1.3 μM relative to the untreated plasma sample. Inter-day reproducibility of migration time is 0.7–1.1 % and for peak area 2.5–3.9 %. The CE method is used to monitor plasma levels of nitrogen metabolites during 60 h of fasting in 10 healthy lean volunteers. T-test showed statistically significant differences in plasma levels of creatine, 2-AB, Ac-carn and most proteinogenic amino acids, which return to their original concentrations after subsequent 48 h recovery.

Conversion of Lithium Chloride into Lithium Hydroxide by Solvent Extraction

A hydrometallurgical process is described for conversion of an aqueous solution of lithium chloride into an aqueous solution of lithium hydroxide via a chloride/hydroxide anion exchange reaction by solvent extraction. The organic phase comprises a quaternary ammonium chloride and a hydrophobic phenol in a diluent. The best results were observed for a mixture of the quaternary ammonium chloride Aliquat 336 and 2,6-di-tert-butylphenol (1:1 molar ratio) in the aliphatic diluent Shellsol D70. The solvent extraction process involves two steps. In the first step, the organic phase is contacted with an aqueous sodium hydroxide solution. The phenol is deprotonated, and a chloride ion is simultaneously transferred to the aqueous phase, leading to in situ formation of a quaternary ammonium phenolate in the organic phase. The organic phase, comprising the quaternary ammonium phenolate, is contacted in the second step with an aqueous lithium chloride solution. This contact converts the phenolate into the corresponding phenol by protonation with water extracted to the organic phase, followed by a transfer of hydroxide ions to the aqueous phase and chloride ions to the organic phase. As a result, the aqueous lithium chloride solution is transformed into a lithium hydroxide solution. The process has been demonstrated in continuous counter-current mode in mixer–settlers. Solid battery-grade lithium hydroxide monohydrate was obtained from the aqueous solution by crystallization or by antisolvent precipitation with isopropanol. The process consumes no chemicals other than sodium hydroxide. No waste is generated, with the exception of an aqueous sodium chloride solution.Graphical

Structural modifications of sinusoidal wavy minichannels cold plates applied in liquid cooling of lithium-ion batteries

In this article, novel configurations of wavy minichannels with both co- and counter-current operation modes are proposed for the thermal management of lithium-ion battery systems, and their performance is investigated by incorporating a 3D conjugative numerical model and an experimental test validation. The structure of each case is specified by variable wavelengths along the flow direction. Three criteria of heat transfer enhancements, temperature uniformity improvements, and flow resistance augmentations are considered to analyze the thermal and hydraulic characteristics of the nonuniform wavy minichannels. The results show that although the Nusselt number of the nonuniform cases is higher than that of the conventional ones (more than15%), they require higher friction factors (between 25.3 % and 93.6 %) to access such Nusselt numbers. At the studied range, a maximum Nu enhancement of 1.18 and a maximum f augmentation of 1.93 are recorded. It is found that the current operation mode is a key factor affecting the temperature uniformity degree. By increasing the coolant velocity from 0.106 to 0.951 m s−1 in the co-current mode, the temperature non-uniformity decreases from 14.79 to 1.10 K, while this range for the counter-current mode is from 6.73 to 0.43 K. It is also found that for a special design of the nonuniform wavy minichannels, the deviations of the temperature non-uniformity at the entire range of the coolant velocity are <0.7 K.

Feasibility assessment of bioethanol production from humic acid-assisted alkaline pretreated Kentucky bluegrass (Poa pratensis L.) followed by downstream enrichment using direct contact membrane distillation

The effective fractionation of structural components of abundantly available lignocellulosic biomass is essential to unlock its full biorefinery potential. In this study, the feasibility of humic acid on the pretreatment of Kentucky bluegrass biomass in alkaline condition was assessed to separate 70.1% lignin and hydrolyzable biocomponents. The humic acid-assisted delignification followed by enzymatic saccharification yielded 0.55 g/g of reducing sugars from 7.5% (w/v) pretreated biomass loading and 16 FPU/g of cellulase. Yeast fermentation of the biomass hydrolysate produced 76.6% (w/w) ethanol, which was subsequently separated and concentrated using direct contact membrane distillation. The hydrophobic microporous flat-sheet membrane housed in a rectangular-shaped crossflow module and counter-current mode of flow of the feed (hot) and distillate (cold) streams yielded a flux of 11.6 kg EtOH/m2/24 h. A modular, compact, flexible, and eco-friendly membrane-integrated hybrid approach is used for the first time to effectively valorize Kentucky bluegrass biomass for sustainable production of biofuel.

Stability performance of series coupled natural circulation system with different operating procedures

Series coupled natural circulation system with the last loop being an open-air loop finds application as an infinite mission time passive decay heat removal system in nuclear power plants and solar thermal systems. Hence the stability behavior of series coupled rectangular loops with horizontal heater and horizontal cooler orientation was experimentally studied. The loop was subjected to various operating procedures viz., start up from rest, power raising from a stable steady state and power step down from an unstable state to witness that the stability threshold was not a unique value, thus confirming the existence of a hysteresis phenomenon. The stability threshold enhancement of the system with orifice plates was maximum for the lowest orifice diameter. The coupled system was chosen with an unstable first loop and the instability was found to transmit from loop#1 to the subsequent loops. However, the oscillation amplitude was highly attenuated and seemed to be nearly stable in the 2nd and 3rd loop without any flow reversals even when the first loop was unstable with chaotic bidirectional pulsing. In case of bi-directional pulsing in loop#1, the heat exchanger between the first two loops operated alternatively in co-current and counter-current mode with no change in the flow direction of loop#2. A delay in the flow initiation was found for start-up from rest, which increased from the first loop to the last loop and decreased with the increase in power input. Further, the numerical simulation with the one-dimensional model reproduced the oscillatory behavior in loop#1, with the predicted stability threshold being considerably lower compared to the experiments. The attenuation of the oscillations in the loop#2 as observed in the experiments could be reproduced. Predicted transients showed practically no oscillations in loop#3 corroborating the experimental observations. The attenuation of the oscillations in loop#2 and the absence of oscillations in loop#3 were attributed to the damping caused by the wall and also due to the higher Lt/D ratio in loop#2 and a vertical air flow channel in loop#3 respectively. The phase plots indicated a near periodic oscillation compared to the highly chaotic pattern in the experiments, presumably due to the higher power at which instability was observed in the experiments. The deviations were also due to the secondary flows being generated in the large diameter loop as the simulation was based on 1D along with the heat loss being neglected.

Separation and extraction of niobium from H2SO4 solution containing titanium and iron impurities

A fluoride-free solvent extraction method for niobium separation in leached sulfuric mother liquor of ilmenorutile was proposed in this paper. The extraction system comprising trioctyl tertiary amine (N235) and 4-methyl-2-pentanone (MIBK) demonstrated good extraction efficiency and selectivity of niobium over titanium and iron impurities in sulfuric acid–oxalate solutions. Details of extraction, scrubbing, and stripping processes were investigated herein, and its practical effectiveness in both batch and multi-stage simulated counter-current modes was verified. Over 73.8% niobium was extracted under optimum conditions, and only 2.8% titanium and 1.7% iron were co-extracted. The recovery of niobium reached 99.1% in the four-stage simulated counter-current extraction tests. In the three-stage simulated counter-current stripping tests, the stripping efficiency of niobium reached 99.7% with 2.0 mol/L HNO3. Qualified niobium oxide products were prepared. The enthalpy change, entropy change, and the standard Gibbs free energy change (ΔHo, ΔSo, and ΔGo, respectively) corroborated the exothermicity, orderliness, and spontaneity of the reaction. The possible composition of the extraction complex was [NbO(C2O4)2(H2O)2]−, as supported by a Fourier transform infrared spectroscopy and ultraviolet–visible spectrophotometry. The extraction mechanism was inferred to be the outer-sphere complexation through physical binding which was the association of R3NH+ in N235 with the [NbO(C2O4)2(H2O)2]−. A preliminary mass balance indicated that 203.92 g Nb2O5 was generated from 1000 g raw material ilmenorutile.

Modernization of operating chicory factories using continuous pulsating extractors

Chicory roots are a valuable source of inulin and other healthy nutrients. The most common direction of their industrial processing is instant chicory powder production. Extraction is the main process in the production. Conventional extraction methods, which include maceration, percolation and extraction in a screw extractor, have a number of significant drawbacks, including high capital and operating costs, low quality of the resulting extract, complexity in repairing equipment, short overhaul life, etc. The purpose of the present study was to assess the technical feasibility of increasing extraction process efficiency through using continuous pulsating extractors (CPE) developed by the Ingehim company, in which a non-stationary, countercurrent mode of interaction of raw materials with the extractant is incorporated. Testing of engineering solutions implemented in CPE was carried out at a pilot pulsating unit (PPU). For extraction, roasted and crushed (5–20 mm) chicory roots from one of the operating chicory factories were used. The ratio chicory : water during extraction was 1 : 4.5, which is 1.5–2.5 times lower than in conventional extractors. A lower extraction temperature (up to 85°C) combined with a shorter extraction time (up to 1 hour) may help retain more inulin and other nutrients as compared to conventional methods. The results of the study at the PPU under these conditions confirmed the high yield of water-soluble solids (up to 98%) without additional grinding. A scheme for the modernization of a chicory factory equipped with the most common percolation extraction equipment having a feed capacity of 400 kg/h is proposed through using CPE. 3D images of the proposed modernization are shown. A comparative assessment of energy consumption for extraction using different methods is given. The results of the study indicate the capability and high efficiency of CPE for extracting chicory, which is confirmed by a decrease of up to 3.6 times in the total specific energy consumption for obtaining 1 kg of instant chicory powder compared to conventional extractors. Low capital and operating costs determine the prospects for using CPE for the modernization of existing chicory factories or the creation of new energy-efficient factories.

A subcritical butane-based extraction of non-psychoactive cannabinoids from hemp inflorescences

Although several extraction methodologies have been reported to date, the development of novel, more powerful, and alternative extraction processes using hemp as the vegetable matrix is still a challenging field of research. In this manuscript the performance of the subcritical butane promoted extraction of a panel of 5 non psychoactive cannabinoids from hemp inflorescences from 2 hemp varieties, under a counter-current mode using a handmade extraction apparatus,was studied. All secondary metabolites under investigation have been finally quantified by gas chromatographic analyses coupled to mass spectrometry. Phyto canabinoids have been extracted in yields from 3.3-fold to 55-fold higher with respect to traditional methods that were adopted herein as a comparison. The use of subcritical butane as the extraction solvent for cannabinoids from hemp inflorescences is reported herein for the first time and could be easily adopted for other matrices (e.g. seeds) deriving from the same vegetable source.