Batch Operation Research Articles

A Numerical Investigation of the Influence of Humid Environments on the Thermal Performance of a Phase Change Thermal Storage Cooling System in Buildings

Phase change thermal energy storage (PCTES) technology has garnered significant attention in addressing thermal management challenges in building HVAC systems. However, the cooling performance of PCTES systems in humid scenarios remains unexplored, which is crucial in subtropical regions, high-humidity underground areas, and densely populated spaces. Taking the mine refuge chamber (MRC) as an example, this study focuses on a passive temperature and humidity control system by employing cold storage phase change plates (PCPs) for 96 h. First, an improved and simplified full-scale numerical model including PCPs and MRC parts is established. Then, the model is validated through the experimental results and solved using a numerical method. Finally, the influence of various factors within the system is investigated and an optimization method involving batch operation is proposed. The results indicate that (1) within 40 h, the use of cold storage PCPs leads to an indoor temperature reduction of 4.8 °C and a 7% decrease in relative humidity; (2) the PCPs show asynchronous states in sensible and latent heat transfer rates; (3) for every 50 additional PCPs, the average indoor temperature increases by 0.6 °C and the relative humidity decreases by 1.5%; (4) implementing batch operation of PCPs ensures that the indoor Heat Index drops by 10 °C, which is vital for human survival. The findings will play a crucial role in the global expansion and application (including geographical and functional aspects) of phase change thermal storage technology.

Recovery of struvite for organic production: Mineral-based magnesium supplementation and pH elevation

Phosphate in wastewater can be recovered in the form of struvite crystals for use as slow-release fertilizer. Currently, struvite recovery often requires supplementing magnesium ions and raising pH with chemicals, making the recovered struvite unfavorable for organic production. In an effort for cleaner production, this study developed a versatile approach employing two mineral products in variable combinations for optimal supplementation of magnesium and elevation of pH. Magnesite, a mineral of MgCO3, was ground and calcined without use of any catalysts. The magnesite calcined under the optimum conditions (800 °C for 30 min) can be dissolved in near-neutral filtrate of sludge digestate to supplement magnesium and raise pH for effective struvite formation. The OMRI-listed Epsom salts (MgSO4∙7H2O), mineral-based water-soluble commercial products, can be used to supplement magnesium without changing pH of alkaline wastewater. Six-hour batch operation of an air-lift crystallizer removed 85.7% and 94.7% of phosphate in hydrolyzed human urine when magnesium was amended to 1.2 × molar concentration of phosphate with calcined magnesite and an OMRI-listed Epsom salt, respectively. More than 98% of phosphate was removed from filtrate of sludge digestate in 3-h batch operation using calcined magnesite to raise pH to 8.5 and the Epsom salt for further magnesium supplementation. Struvite accounted for 85.7%, 90.5%, and 81.5% of the crystals recovered from urine with calcined magnesite, urine with Epsom salt, and filtrate with both mineral products, respectively. The material and energy costs of this green process were estimated to be $0.16/kg struvite from urine with calcined magnesite, $1.37/kg struvite from urine with Epsom salt, and $0.94/kg struvite from filtrate with both mineral products. This study proved the technical and economic feasibility of chemical-free magnesium supplementation and pH elevation, making the recovered struvite potentially certifiable for organic production.

A comprehensive study of melt foaming in E‐glass batch‐to‐melt conversion process: Effects of sulfate content and chemistry of raw materials

AbstractControl of sulfate‐induced melt fining without excessive foaming is one of the critical steps in maintaining the stability of E‐glass fiber manufacturing processes. Besides, the efficiency of combustion or energy utilization is directly affected by the extent of the melt‐foaming. A fundamental understanding of key factors affecting melt foaming under the simulated oxy‐fuel combustion environment will enable commercial E‐glass fiber production to optimize both batch chemistry and operation conditions to achieve adequate furnace control. In this study, six types of E‐glass batches with the same target glass composition were prepared by using four different CaO sources; calcined limes with different SO3 contents, limestone, limestone with sodium sulfate, and a mixture of limestone and calcined lime. All batch samples were examined by HTMOS‐EGA system (high temperature melting observation system with evolved gas analysis). HTMOS enables monitoring batch‐to‐melt conversation steps by using a high‐resolution camera and EGA detects the evolved reaction gaseous, such as CO, CO2, and SO2 via an Fourier transform infrared (FTIR) gas analyzer. Gases of water vapor, N2, and O2 were introduced accordingly into the fused quartz crucible to simulate similar oxy‐fuel atmosphere of the furnace operation. This study aimed to investigate the effects of different SO3 contents in batches and different raw material chemistries on the foam formation in E‐glass melts under the oxy‐fuel atmosphere. Different raw materials were characterized by mineralogical analysis, chemical analysis, particle size distribution, chemical oxygen demanding (COD) level, and Brunauer–Emmett–Teller (BET) analysis. Although some of the batches contained the same SO3 content, different foam formations resulted from the effect of the batch chemistry. Our detailed HTMOS‐EGA investigations show that not only SO3 content in the batch affects foam formation in E‐glass melts, but also raw material chemistry and particle size have strong effects on the melt foaming in E‐glass batch melting, especially for those of ingredients having hydroxide phases and/or finer particles with higher specific areas.

Fault Detection and Isolation in Simulated Batch Operation of Fine Motion Control Rod Drives

Control rods and elements manage the power distribution in nuclear reactors through the motion of banks of rods distributed throughout the core. These positional changes are achieved through the actuation of fine motion control rod drive (FMCRD) mechanisms. In the BWRX-300 design by GE-Hitachi, this mechanism is electrically driven by a servomotor that allows for high-precision control of power outputs. Under operational transients, such as load-following, accurate and precise operation of these servomotors is necessary over long periods of time, so they are key maintenance targets to maintain availability and operational flexibility. Swiftly and precisely identifying faults in the drive mechanisms will support predictive maintenance and reduced costs. This paper used three different types of simulated faults to test the fault detectability of principal component analysis (PCA) when considering the simulated operations of banks of control rods and their associated servomotors. These faults were stator short-circuit faults, ball screw jam faults, and ball screw wear faults. Torque and position were monitored in the simulation. The position signal was insufficient to detect mechanical faults. Torque signals for each servomotor in the bank of rods undergoing multiple position demand changes were projected to a reduced dimensional space via PCA. Q and T2 statistics were employed for anomaly detection. Using this approach, all faults were detected, and the anomalies were isolated to the faulty FMCRD mechanism.

Precious metal-based Catalytic Membrane Reactors for continuous flow catalytic hydrodechlorination

This work is focused on the development of Catalytic Membrane Reactors (CMRs) comprising precious metals as active phases for a comparative assessment in continuous-flow catalytic hydrodechlorination (HDC). HDC has proved its remarkable potential for application as polishing step in drinking water treatment plants, but studies operating in continuous mode are scarce. Preliminary experiments were conducted in batch operation using Pd/Al2O3, Rh/Al2O3 and Pt/Al2O3 powder catalysts to evaluate the influence of the active phase on the removal of prochloraz (PCZ) (100μgL-1), a pesticide listed on the EU Watch List (2022/1307), by HDC. PCZ removal was successfully described by a pseudo-first order kinetic equation and reaction pathways were proposed. Among the catalysts tested, Pt-based suffered a significant deactivation, not warranting the elimination of this micropollutant. Pd/Al2O3 exhibited a faster removal of PCZ than Rh/Al2O3, while this catalyst resulted in further hydrogenation of the non-chlorinated reaction product. Accordingly, different CMRs were developed by decorating cylindrical inert porous alumina membranes with Pd, Rh, and a combination of Pd-Rh as active phases (~1% wt.). All CMRs showed a remarkable stability along 100h on stream, being Pd/CMR be the most effective, with a pseudo-first order rate constant value of 0.062 min-1. An assessment of the impact of operating conditions (aqueous flow rate, PCZ initial concentration, temperature and H2 flow rate) was conducted using the Pd/CMR, which notably remained stable for 450h on stream. The versatility of the system was finally demonstrated in tap water, achieving a steady-state PCZ conversion close to 95%.

Biosorption of au from leachates of waste printed circuit boards by baker's yeast

A microbial method using commercially available baker's yeast was developed for efficiently and selectively collecting aqueous Au(III) ions in aqua regia leachates from waste printed circuit boards (PCBs) through biosorption under air at temperatures ranging from 10 °C to 34 °C. Even when the total concentration of base metals was much higher than the initial Au concentration in the PCB leachate with high acid concentrations of 4.7–5.6 mol/L, commercial dry baker's yeast exhibited an excellent ability to selectively collect aqueous Au ions from the leachate within 60 min. When the biosorption test was repeated as a three-stage batch operation, the percentage biosorption of Au from the PCB leachate increased from 61% to 99% with 36 g/L dry yeast cells at 34 °C. The experimental results for the three-stage batch biosorption test were consistent with theoretical predictions based on the material balance of Au in multistage equilibrium operations and the distribution coefficient of Au. Equilibrium data of the Au biosorption conformed to the linear isotherm, regardless of the yeast concentration and the initial Au concentration in the leachate. The distribution coefficient KAu at 34 °C decreased by 30%, from 53.7 to 37.3 L/kg-dry cells, as the total base metal concentration in the leachate was increased tenfold, from 1.94 to 16.4–19.1 g/L. Moreover, the distribution coefficient of Au at 10 °C to 34 °C was analyzed to determine thermodynamic parameters according to the van't Hoff equation. The thermodynamic studies indicated that the biosorption of aqueous Au ions by baker's yeast was spontaneous and exothermic.

Semicontinuous Blending of Pharmaceutical Ingredients and the Impact of Process Parameters on the Blending Performance of an Integrated Feeder Blender Operating Semicontinuously

The pharmaceutical industry is looking for new and innovative ways of manufacturing to improve product quality and reduce process complexity. In manufacturing oral solid dosage products, blending is a crucial step in ensuring the homogeneity of active pharmaceutical ingredients (APIs) in the final product. Currently, batch and continuous blending are the two commonly used modes for blending in the industry. However, these methods have limitations in terms of blending time, manual intervention, and flexibility in handling multiple ingredients. To address these limitations, this study aims to explore the feasibility and benefits of using a semicontinuous blending mode in the pharmaceutical industry. A case study is conducted using a binary blend of microcrystalline cellulose and acetaminophen to compare the performance of the semicontinuous mode of blending with the batch and continuous blending modes. The results show that the semicontinuous blending setup can produce blends with good blend uniformity and homogeneity and that the output can be used for both batch and continuous downstream operations. The effect of variation in the three most important process parameters, impeller rotation per minute, blending time, and fill level on the blend uniformity, is also investigated. The semicontinuous blending mode had a higher line rate of 12.5 kg/hour than a similarly sized batch blender at 3.6 kg/hour and less than that of a continuous blender. The benefits of the new blending mode include reduced blending time, minimal manual intervention, flexibility in blending multiple ingredients, easier scale-up, and a smaller footprint. Overall, this study highlights the relative advantages of using this new semicontinuous blending mode in pharmaceutical manufacturing and its potential as a good alternative to the existing blending modes. The semicontinuous mode is well placed between the batch blending and continuous blending mode, with many benefits over the former mode and performance comparable to the latter continuous mode.

Insights into metal wear and particle breakage using Bond's abrasiveness test

Nearly 80 years ago Fred Bond proposed his abrasiveness test, also known as Allis Chalmers abrasion test, together with empirical equations that have been used to predict the wear of mill and crusher liners, besides grinding media. Although those equations have been widely criticized over the years, in particular owing to the limited accuracy of the correlations originally proposed to predict wear, it remains the most widely used test to measure ore abrasiveness in the minerals industry. The work analyzes the test, through experiments conducted under conditions that differ from those originally proposed by Bond in order to gain insights on metal wear and particle breakage. The effects of particle size, ore competence, metal hardness and time of batch operation are analyzed. It is shown that initial particle size strongly affects the rate of wear, that the intensity of fragmentation varies with hardness of the paddle and that the size distribution from the ground material offers a valid proxy for ore competence that may be useful in geometallurgical studies.

Valorization of Field-Spent Granular Activated Carbon as Heterogeneous Ozonation Catalyst for Water Treatment.

Developing sustainable cost-effective strategies for valorization of field-spent granular activated carbon (s-GAC) from industrial water treatment has gained much interest. Here, we report a cost-effective strategy for the regeneration of s-GAC as an adsorbent in a large-scale drinking water treatment plant and used as an efficient and durable ozonation catalyst in water. To achieve this, a series of samples is prepared by subjecting s-GAC to thermally controlled combustion treatments with and without pyrolysis. The catalytic performance of the optimized sample is evaluated for oxalic acid degradation as the model pollutant under batch (>15 h) and continuous flow operations (>200 h). The partially deactivated catalyst upon reuse is restored by thermal treatment. Electron paramagnetic resonance and selective quenching experiments show the formation of singlet oxygen (1O2) during catalytic ozonation. The GAC-ozonation catalyst is efficient to minimize the formation of chlorinated disinfection by-products like trihalomethanes and haloacetic acids in an urban wastewater effluent.

KINETICS AND MECHANISM MODELLING OF Pb(II) AND Ni(II) IONS SORPTION FROM AQUEOUS MEDIUM: EVALUATING THE PERFORMANCE OF Curcuma longa RHIZOME IN THE TREATMENT OF WASTE WATER.

In this research Curcuma longa Rhizome, an agricultural product, available in large quantity in northern Nigeria, were used as low-cost adsorbent for removal of Pb(II) and Ni(II) ions from aqueous medium. Batch operation was used to study the equilibrium behaviour of Curcuma longa rhizome. The effect of solution pH, and contact time on the adsorbent for the removal of Pb(II) and Ni(II) ions were evaluated. To study the adsorption kinetics of Pb(II) and Ni(II) ions onto Curcuma longa Rhizome, pseudo-first-order, pseudo-second-order as well as three diffusion models: intraparticle diffusion model (Weber and Morris model), film diffusion model (McKay model) and liquid film Models were used. The sorption kinetics can be described well by the pseudo-second-order model due to the closeness between the qexp ( 49.26 mg/g) and qcal (52.63 mg/g) for Pb(II) and qexp (57.60) and qcal (55.56 mg/g) for Ni(II) ions. Moreover, the rate limiting step are liquid film and intraparticle diffusion controlled. In addition, the results suggest that Curcuma longa Rhizomes are very effective adsorbent for the removal of Pb(II) and Ni(II) ions from aqueous medium. This will serve as an indicator to consider in the design for waste water treatment plant for heavy metal detoxification using Curcuma longa Rhizome.

Comparison of batch, fed-batch and continuous operation modes for scalable polyhydroxyalkanoate (PHA) production and carbon sequestration from phenol

Polyhydroxyalkanoates (PHA) are biodegradable intracellular polymers, and a renewable alternative to conventional plastics. To reduce PHA's cost, this study combined an unconventional carbon source, i.e. a toxic aromatics phenol, with an acclimated consortium, to develop a scalable PHA production process. The resultant process performance was systematically compared across three operational modes: batch, fed-batch, and continuous. Phenol toxicity caused inhibition in the batch mode, reducing the PHA synthesis rate but resulting in a high PHA content in cells (PHA% > 50 %). Fed-batch feeding alleviated such inhibition, facilitating a high PHA titer and yield from the substrate. Interestingly, a higher feeding rate in the fed-batch reactor improved its performance, probably by providing a suitable food-to-microbe ratio for the biomass. Using a continuous mode also reduced phenol toxicity, but resulted in more synthesis of non-PHA cellular materials (NPCM). The difference might have been caused by different metabolic states and the presence of intermediates in the reactors. Comparing all 14 conditions under the three modes, feeding phenol more gradually tended to channel substrate away from PHA to NPCM synthesis. The volumetric productivity generally ranged from 3 to 12 mg L−1 min−1, while the biomass productivity was between 2 and 11 mg g initial CDW−1 min−1. A 3-stage, production-harvest and starvation-production process was then designed to simulate real industrialized manufacturing, where the operational modes had a long-term effect on biomass' productivity. Fed-batch mode performed the best, as it fixed 1/3 of phenol's organic carbon in PHA product, suggesting high potential for future application.

Room‐Temperature, Meter‐Scale Synthesis of Heazlewoodite‐Based Nanoarray Electrodes for Alkaline Water Electrolysis

AbstractAlkaline water electrolysis is among the most promising technologies to massively produce green hydrogen. Developing highly‐active and durable electrodes to catalyze the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) is of primary importance. Here a facile, room‐temperature synthetic route is presented to access heazlewoodite phase (Ni, Fe)3S2 nanosheet arrays supported on NiFe foam (NFF), whose production can be easily scaled up to meter size per batch operation. The (Ni, Fe)3S2/NFF electrode can serve as a high‐performance electrocatalyst for both HER and OER in alkaline media, and remains highly stable for over 1000 h at 100 mA cm−2 current densities. When working as HER electrocatalyst, (Ni, Fe)3S2 is confirmed as catalytic phase that provides a high density of efficient active sites (e.g., Ni─Ni and Ni─Fe bridge sites). During electrochemical OER testing, (Ni, Fe)3S2 nanosheets totally transform into γ‐(Fe, Ni)OOH as active catalytic phase for OER. As a consequence, the (Ni, Fe)3S2/NFF can be used to integrate into an alkaline electrolyzer as both the cathode and anode, and to give an excellent catalytic performance (600 mA cm−2 @1.93 V), which is better than the alkaline electrolyzer based on commercial Raney Ni electrodes.

Towards sustainable charcoal production: Designing an economical brick kiln with enhanced emission control technology

In this research, a brick kiln integrated with pollutant emission control technology was designed and applied in order to produce charcoal from Eucalyptus Globules wood. The batch operation carbonization of wood biomass was undertaken in a 1.25 m3 volume brick kiln. A wet-packed scrubber was designed and constructed by filling gravels in a depth of 40 cm with aggregate sizes of 48–60 mm, 27–33 mm and 16–20 mm from the bottom to the top respectively aiming to treat emission from the charcoal-producing unit. The characteristics of the charcoal produced were determined to be composed of 9% moisture content, 1.5% ash content, 38% charcoal yield and a heating value of 27.53 MJ/kg. On the other hand, the wet scrubber integrated into a brick kiln was found to remove Hydrocarbons, CO2 and CO by 97.8%, 98.5% and 99% respectively, which makes it efficient and practical way of controlling the gasses released during producing of charcoal.

Study on various hot-gas defrosting configurations for CO2-NH3 cascade deep freezer

Four hot-gas bypass defrosting configurations for CO2-NH3 cascade blast freezer for application in fish processing firm are numerically investigated. Due to the high moisture content of fish, defrosting is necessary after every 4 to 5 h of batch operation. A thermodynamic model for the cascade system and defrosting was developed to study various defrosting configurations formulated by rearranging the existing compressor to operate as a defrosting compressor and with the addition of an external defrosting compressor. From the simulation findings, it can be summarized that the conventional hot-gas bypass defrosting without defrost compressor is suitable for a high-capacity cascade refrigeration system with more than three evaporators. For low cooling capacity refrigeration systems, a defrosting compressor is necessary to elevate the temperature above the cascade condensing temperature. A dedicated defrosting compressor with a power consumption of 3.1 kW and a modified refrigeration/defrosting compressor with a power consumption of 6.8 kW can deliver 33.3 kW of heating at a temperature of +10 °C (45 bar). Incorporating a desuperheater between the main and defrosting compressors reduces compressor temperature and maintains the lubricating oil stability, without change in defrosting energy consumption and less exergy loss. The defrosting efficiency is obtained in the range of 39.7–42% which is in agreement with published literature.

Thermal and alkaline pre‐treatments of inoculum halt methanogenesis and enable cheese whey valorization by batch acidogenic fermentation

AbstractBACKGROUNDCarboxylates such as volatile fatty acids (VFA) can be produced by acidogenic fermentation (AF) of dairy wastes including cheese whey, a massive residue produced at 160.67 million m3 of which 42% are not valorized and impact the environment. In mixed‐culture fermentations, selection pressures can favor AF and halt methanogenesis. In this study, inoculum pre‐treatment was evaluated as a selective pressure for AF demineralized cheese whey in batches. Alkaline (NaOH, pH 8.0, 6 h) and thermal (90 °C for 5 min, ice‐bath until 23 °C) pre‐treatments were tested with batch operations runs at initial pH 7.0 and 9.0, food‐to‐microorganism (F/M) ratios of 0.5 to 4.0 g COD g−1 VS, and under pressurized (P) and nonpressurized (NP) headspace, in experiments duplicated in two different research institutes.RESULTSAcetic acid was highly produced on both Unicamp and TU Delft samples (1.36 and 1.40 g CODAcOH L−1, respectively), at the expense of methanogenesis by combining a thermal pre‐treatment of inoculum with a NP batch operation started at pH 9.0. Microbial communities comprising VFA and alcohol producers, such as Clostridium, Fonticella and Intestinimonas, and fermenters such as Longilinea and Leptolinea. The lipid‐accumulating Candidatus microthrix was observed in both bulk material and foam. Despite the absence of methane production, Methanosaeta were detected within the microbial community. An F/M ratio of 0.5 g COD g−1 VS led to the best VFA production of 1769.4 mg L−1.CONCLUSIONOverall, inoculum thermal pre‐treatment, initial pH 9.0 and NP headspace acted as a selective pressure for halting methanogenesis and producing VFAs, valorizing cheese whey via batch acidogenic fermentation. © 2024 Society of Chemical Industry (SCI).

Phytohormone Supplementation for Nutrient Removal from Mariculture Wastewater by Oocystis borgei in Sequential Batch Operation

To enhance the nutrient removal efficiency of Oocystis borgei for mariculture wastewater (MW), the effects and processes of three phytohormones on nitrogen and phosphorus removal from synthetic mariculture wastewater (SMW) by O. borgei under sequential batch operation were compared. The findings revealed that the supplementation with 10−6 M 3-indoleacetic acid (IAA), gibberellic acid (GA3), and zeatin (ZT) resulted in the most effective elimination, while there was no appreciable difference among them. The nitrogen and phosphorus indices of the effluent dramatically reduced (p < 0.01) upon the supplementation of phytohormones, and the removal effects were ranked as NO3−-N > PO43−-P > NH4+-N > NO2−-N. The removal rates for NH4+-N and PO43−-P were 0.72–0.74 mg·L−1·d−1 and 1.26–1.30 mg·L−1·d−1, respectively. According to physiological studies, phytohormones enhanced the levels of photosynthetic pigments and chlorophyll fluorescence parameters (Fv/Fm and φPSII), thereby improving photosynthetic activity. Additionally, they stimulated Nitrate Reductase (NR) and Glutamine Synthetase (GS) activities to promote nitrogen metabolism and increased Superoxide Dismutase (SOD), Catalase (CAT), and carotenoid contents to mitigate oxidative stress damage caused by abiotic stress. These activities contribute to the proliferation of O. borgei, which in turn resulted in an increase in the assimilation of nitrogen and phosphorus from SMW. In conclusion, phytohormone supplementation significantly increased nutrient removal from SMW by O. borgei in a sequential batch reactor, which has potential application in MW treatment.

Purification of used cooking oil using natural corn cob and carbon corn cob as adsorbent with batch operation

Adsorption is one of the processes used to purify used cooking oil by using adsorbents from natural and carbonized corn cob as part of sustainability. The adsorption process is chosen because it is more economical, efficient, relatively affordable cost, and can be regenerated. This study was conducted in batches to observe changes in the quality of used cooking oil at certain time intervals and to determine the modeling of adsorption kinetics on natural corn cob and carbonized corn cob adsorbents. The sample of this study is 100 ml of used cooking oil with adsorbents in the form of natural corn cob and carbonized corn cob with a mass of 3 grams and a particle size of 70 mesh. This study’s best adsorption result is corn cob carbon adsorbent. This can be seen from the final turbidity value of 37.3 NTU compared to the natural corn cob adsorbent of 37.6 NTU. This study found that the adsorption process that occurs has chemical interactions as evidenced by second-order pseudo-modeling, which has a correlation coefficient close to one.

Adsorption of rare earth elements on a magnetic geopolymer derived from rice husk: studies in batch, column, and application in real phosphogypsum leachate sample.

There is a growing need to develop new strategies for rare earth element (REE) recovery from secondary resources. Herein, a novel approach to utilize biogenic silica (from rice husk) and metakaolin was employed to fabricate magnetic geopolymer (MGP) by incorporating metallic iron. The fabricated MGP adsorbent material was used to uptake Ce3+, La3+, and Nd3+ from synthetic solutions and real phosphogypsum leachate in batch and column modes. The MGP offers a negatively charged surface at pH above 2.7, and the uptake of REEs rises from pH 3 to 6. The kinetic study validated that the kinetics was much faster for Nd3+, followed by La3+ and Ce3+. A thermodynamic investigation validated the exothermic nature of the adsorption process for all selected REEs. The desorption experiment using 2mol L-1 H2SO4 as the eluent demonstrated approximately 100% desorption of REEs from the adsorbent. After six adsorption-desorption cycles, the MGP maintained a high adsorption performance up to cycle five before suffering a significant decrease in performance in cycle six. The effectiveness of MGP was also assessed for its applicability in recovering numerous REEs (La3+, Ce3+, Pr3+, Sm3+, and Nd3+) from real leachate from phosphogypsum wastes, and the highest recovery was achieved for Nd3+ (95.03%) followed by Ce3+ (86.33%). The operation was also feasible in the column presenting suitable values of the length of the mass transfer zone. The findings of this investigation indicate that MGP adsorbent prepared via a simple route has the potential for the recovery of REEs from synthetic and real samples in both batch and continuous operations modes.

One‐pot Heterogeneous Biocatalysis under Thermal Decay for Fructose Production from Lactose using Co‐Immobilized Enzymes: Modeling and Simulation

AbstractMulti‐enzyme reaction systems have become an interesting option to avoid transformation and purification steps in productive reactor‐based systems; when carried out in a single vessel, they are termed one‐pot systems. This novel work aims to model and simulate the behavior of a one‐pot heterogeneous catalysis system in a batch‐stirred bioreactor and in a continuous stirred bioreactor with co‐immobilized enzymes to determine the compromise operation temperature that maximizes the volumetric productivity, considering thermal decay of the biocatalyst. The production of fructose from lactose is considered a case study, using co‐immobilized ‐galactosidase ( ‐gal) and glucose‐isomerase (GI) in a spherical particle. A diffusion and reaction mathematical model was used to calculate the effectiveness factor for every reaction species considering the thermal decay of both enzymes. Simulations in both batch and continuous operation were done at temperatures ranging from 40 to 60 °C, for initial enzyme activity load ratios ranging from 0.1 to 0.9 IUGI IU . Resulting effectiveness factors were close to one, indicating no significant limitations on reaction rates due to internal diffusional constraints. In both cases, temperature exerted a more substantial effect than the initial enzyme activity load ratio, showing different scenarios of high volumetric productivity (batch) or amount of produced fructose (continuous).

Proceedings of the 2023 Viral Clearance Symposium, Session 4: Continuous Processing.

The continuous processing session at the 2023 Viral Clearance Symposium (VCS) focused on understanding how to effectively design viral clearance operations for use in continuous processes and methods to perform viral clearance studies. In this session, an approach to directly address control considerations with operating continuous-flow reactors for low pH viral inactivation was presented. Continuous-flow low pH incubation chamber design and implications for residence time determination were discussed. Additionally, viral clearance capability between batch operation and connected operation were demonstrated to be comparable for a connected bind-elute chromatography and flow-through chromatography step. Overall, this session provided additional scientific knowledge to support viral clearance strategies when implementing a continuous manufacturing process.