Laboratory Reactor Research Articles

Catalytic purification of helium concentrate from hydrogen: catalysts, conditions and features of the process

The paper presents the results of a study of Pt and Pd catalysts deposited on porous aluminum oxide in the reaction of hydrogen oxidation reaction for use the process of helium concentrate purification. The properties of the prepared catalysts were compared with the properties of a foreign reference catalyst. In a laboratory reactor using a mixture simulating helium concentrate, we studied the “ignition” and deactivation of catalysts at room temperature, which simulates the conditions at the inlet section of an industrial adiabatic reactor. The properties of catalysts were also studied at temperatures of 200, 250 and 300 °C under conditions simulating the middle part and the outlet of an industrial reactor. The secondary process of hydrogen formation at 250-300 °C was studied, which is explained by methane and ethane steam reforming which present in the model mixture simulating helium concentrate. The results of the work can be used in the development of domestic catalysts for the purification of helium obtained from natural gas.

A Study on the Potential for the Application of Peanut Shells as a Reducer in the Process of Metal Recovery from Metallurgical Slags

Copper production technology is a complex process consisting of many stages. The combination of pyrometallurgical and hydrometallurgical stages, on the one hand, complicates production while, on the other hand, allowing for a relatively selective separation of intermediate or waste materials that can be subjected to the process of recovery of useful components. Materials of this type are characterised by a much higher copper content relative to the ore material. On the other hand, due to the oxide form, reduction processes are used in which coke is mainly applied. Reduction of the unfavourable phenomenon of CO2 emissions, in this case, can be performed through the use of bioreducers, which are characterised by an inert carbon footprint since the generation of carbon dioxides is the same as its absorption at the stage of vegetation and growth. In this paper, the topic of determining the feasibility of using selected bioreducers, such as peanut shells, to verify their suitability in the process of reducing copper oxides as well as the impact on the working components of the laboratory reactor in which the process is carried out are discussed. In this case, raw materials with a composition similar to the that of slags produced at the copper production stage in a flash furnace were tested for reduction. The results referring to reducing lead and copper contents above 88% Pb and 98% Cu indicate the great potential of this type of bioreducer. An additional advantage is the relatively wide availability of peanut resources. The effects of the copper reduction time on the degree of decopperisation performed with a constant reducer addition at 1300 °C were studied in this paper. Following 1 h of the process, the copper content in the slag was 0.78 wt%, while the longer process duration resulted in a copper fraction of 0.19 wt%. Considering lead, its content was 0.33 wt% after the reduction process.

Exploring the role of hydrogen peroxide dosage strategies in the photo-Fenton process: Scaling from lab-scale to pilot plant solar reactor

This study aims to investigate the role of hydrogen peroxide (HP) continuous dosage in removing Paracetamol (PCT) from different water matrices using the solar photo-Fenton process. Different parameters in the HP dosage strategies (initial HP pulse, dosing time, and HP concentration) were systematically analysed to assess their impacts on pollutant removal (XPCT), oxidant specific consumption (YHP/PCTt), and toxicity levels (I(%)). The analysis involved various water matrices (ultrapure water UW, groundwater GW, anion matrix AW, and synthetic pharmaceutical wastewater IW0.01 or IW0.1), which were firstly treated in a laboratory reactor and subsequently scaled up to a solar prototype. After laboratory testing, the most effective reaction configuration (maximum XPCT and YHP/PCTt close to the stoichiometric one) was chosen as the starting point for scaling up the reaction system. Using the solar reactor setup, complete PCT conversion was achieved within just 60 min of reaction time (UW matrix). However, under IW0.1 condition and employing the same HP dosing strategy, a XPCT of 95.4 % was attained but at 180 min of reaction, highlighting the significant influence of the real matrix. Additionally, the I(%) remained high towards the end of the reaction (close to 60 %), attributed to the presence of hydroquinone in the system, demanding longer reaction times to completely reduce the toxicity when working with industrial wastewater. This comprehensive approach aims to close the gap between lab results and practical applications, offering crucial insights to address pharmaceutical wastewater pollution.

Performance Assessment Analyzes of Research Nuclear Reactors Based on Steady-state and Kinetic Models

The mainstays of nuclear substance radiation and isotopic synthesis are nuclear-powered power plants, however effective safety evaluation is made tougher by the complicated construction topologies and physical connection effects. This work proposes a multiphysics-linked technique for evaluating both the kinetic and steady-state behaviors of the MPRR and LVR-15 laboratory reactors. To represent complicated member geometries, homogenized assembling sections are generated using two-dimensional whole-core computational simulations. It is discovered that the steady-state findings and the so-called Monte Carl solution comparisons correspond quite nicely. The greatest assemble power mistakes for LVR-15 and MPRR are 6.49%/10%, and the highest command rod value mistakes are 31 pcm/136 pcm, and the mistakes are 377 pcm/383 pcm, accordingly. Meanwhile, the study is done on transitory procedures, such as reactivity-initiated disasters and exposed loss-of-flow mishaps. Both units' modeling findings show plausible adverse feedback events. Furthermore, it is shown that the two reactors' accident-related behaviors are comparable though having different core architectures since they employ the exact same kinds of water as a fluid. The technique for studying nuclear power plant kinetics known as Multi-Physics Simulation (MPM) is explained. Drawing on many research and verification efforts conducted at Politecnico di Milan, Italy, MPM is shown to be a valuable instrument for managing reactors' security and oversight. It may be viewed as a holistic analytical tool that is implemented during the reactor architecture design phase. The capacity to concurrently answer the interrelated equations that control the many physical processes taking place in a nuclear plant inside the same simulated setting is a core characteristic of MPM.

Voltage recovery from frozen microbial fuel cells in the laboratory and outdoor field reactors

Extreme temperature variations are a problem that must be faced in the practical application of microbial fuel cells (MFCs), but MFCs are not extensively described for low and even freezing temperatures. This study assessed the effect of low-temperature shock on the power generation performance and microbial community structure of MFCs. Two scales of MFCs, the small (mL-MFC) and the large (L-MFC), were constructed in the laboratory and their performance was evaluated before and after freezing at −18 °C. The experimental results demonstrate that both MFCs were capable of rapidly restoring their voltage to the previous level after thawing. For the mL-MFC (rGO/Ag), the power density recovered from 194.30 ± 10.84 mW/m2 to 195.57 ± 4.02 mW/m2 after thawing. For L-MFC (carbon felt electrodes), the power density increased significantly from the initial 1.79 mW/m2 to 173.90 mW/m2 after thawing, but the performance degradation problem after reactor amplification still needs to be solved. The sediment microbial fuel cell (SMFC) was successfully constructed and operated in a natural outdoor environment to maintain high voltage output after the period of frost. Microbial analysis indicated after the frost period, psychrotolerant microorganisms enriched on the anode, such as Flavobacterium and Psychrobacter, while the relative abundance of anaerobic methanogenic bacterium decreased. Overall, freeze-thaw operations had a non-negative impact on the performance of MFCs and provided some references for their practical applications.

Escherichia coli removal in down-flow hanging sponge reactors: insights from laboratory reactor studies

Down-flow hanging sponge (DHS) reactors, employed in domestic wastewater treatment, have demonstrated efficacy in eliminating Escherichia coli and other potentially pathogenic bacteria. The aim of this study was to elucidate the mechanism of removal of E. coli by employing a cube-shaped polyurethane sponge carrier within a compact hanging reactor. An E. coli removal experiment was conducted on this prepared sponge. Escherichia. coli level was found to decrease by more than 2 logs after passing through five nutrient-restricted DHS sponges. Conversely, a newly introduced sponge did not exhibit a comparable reduction in E. coli level. Furthermore, under conditions of optimal nutritional status, the reduction in E. coli level was limited to 0.5 logs, underscoring the crucial role of nutrient restriction in achieving effective elimination. Analysis of the sponge-associated bacterial community revealed the presence of a type VI secretion system (T6SS), a competitive mechanism observed in bacteria. This finding suggests that T6SS might play a pivotal role in contributing to the observed decline in E. coli level.

Technology of dry extract from the <i>Filipendula ulmaria</i> (L.) Maxim. and preliminary assessment of its safety profile

Introduction. Medicines of natural origin have advantages over synthetic drugs and occupy a significant share in the assortment of pharmacies. Filipendula ulmaria (L.) Maxim., characterized by a chemical composition rich in phenolic compounds and various types of biological activity has the potential in terms of the development of new herbal medicines. In an in vivo experiment, F. ulmaria extract showed immunomodulatory, anti-inflammatory, osteogenic activity and effectively stimulated myelopoiesis in conditions of microbial damage of bone tissue.Aim. Development of an optimal technology for obtaining dry extract of F. ulmaria by remaceration and investigation of its аcute toxicity.Materials and methods. The technology of extract was developed in a laboratory reactor equipped with a water heater jacket and a stirrer. The content of flavonoids was determined by differential spectrometry. Flowability was determined on a flowability tester for powders and granules, bulk density was determined on a bulk density tester for powders and granules, moisture content was developed on a moisture content analyzer. Acute toxicity was determined on Wistar rats.Results and discussion. The dry extract of F. ulmaria, obtained using 70 % ethanol by remaceration, is effective in conditions of microbial damage of bone tissue and bone marrow, which determined the choice of extragent and the type of extract. The optimal parameters for obtaining the extract were determined (three-fold maceration at a water jacket temperature of 80 °C, the ratio of raw materials to extragent 1 : 14, time 30 min), its main technological characteristics were determined and a wet granulation method for improving them was proposed. In the study of acute toxicity of the extract, according to the results of toxicometry for 14 days after administration and necropsy data, the studied extract was classified as low-toxic substance.Conclusion. The dry extract of F. ulmaria, obtained by remaceration using 70 % ethanol, has specific activity in conditions of microbial damage to bone tissue. Optimal extraction parameters allow to increase the yield of target components, it is advisable to improve the technological parameters of the extract by wet granulation. The assessment of the safety profile of the dry extract from F. ulmaria, along with its high biological activity, provides a perspective for its further study and implementation into medical practice.

Impact of mild hydrothermal aging on kinetics of NH[formula omitted], NO, SO[formula omitted] and CO oxidation reactions on Cu/SSZ-13 catalyst

Cu/SSZ-13 is a catalyst commonly used for selective catalytic reduction (SCR) of nitrogen oxides (NOx) in diesel engine exhaust. Standard configurations are based on SCR preceded by an oxidation catalyst, however, a close-coupled SCR configuration appears relevant for upcoming regulations addressing cold-start emissions. Two often discussed ion-exchanged Cu sites in Cu/SSZ-13 are denoted ZCuOH and Z2Cu, where Z represents an Al atom in the zeolite framework. Mild hydrothermal aging (HTA) causes Cu redistribution within the catalyst; ZCuOH sites transform into more stable Z2Cu species. In this work, the effect of mild HTA on NH3, NO, SO2, and CO oxidation is studied on a commercial Cu/SSZ-13 sample. Temperature-programmed reaction experiments, performed in a lab reactor, and previously published catalyst characterization data using H2-TPR, NH3-TPD, and DRIFTS were used to build and validate a mathematical model. It couples the kinetics of the oxidation reactions with ZCuOH and Z2Cu concentration evolution during mild HTA. The model uses two distinct rate coefficients for ZCuOH and Z2Cu sites, allowing prediction of the catalyst activity during aging. The results suggest that the rate coefficients for the studied reactions on Z2Cu are effectively nil, so the observed activity in NH3, NO, SO2, and CO oxidation can be attributed solely to ZCuOH sites.

Agglomeration of coal and polyethylene mixtures during fixed-bed co-gasification

The article presents the results of experimental studies on the gasification of mixtures of brown coal and polyethylene (up to 20 wt% fraction) in a laboratory reactor. The work aims to study the agglomeration process during the heating and oxidation of the mixtures. The measurement results (gas composition, pressure drop) provide indirect information on the dynamics of thermal decomposition and structural changes in the fuel bed. We have shown that the interaction between polyethylene and a coal surface leads to the formation of dense agglomerates, in which the molten polymer acts as a binder. Clinkers form as a result of interfacial interactions between components and filtration flow rearranging. The hydrogen/carbon ratio in the solid residue of coal-polyethylene co-gasification increases from 0.07–0.2 to 1.11, indicating the formation of stable hydrocarbon compounds on the carbon surface. The conducted research makes it possible to identify possible interactions between chemical reactions and transfer processes that lead to agglomeration in mixtures of coal with polyethylene.

Distribution of Copper, Iron, and Sulfur in Copper Concentrate Particles during Oxidation under Simulated Flash Smelting Conditions

The distribution of copper, iron, and sulfur during the oxidation of La Caridad copper concentrate particles under simulated flash smelting conditions was studied in a laboratory reactor. Six wet-sieved size fractions and the unsieved copper concentrate were oxidized at 1123 K and 40% and 70% O2 by volume in the process gas during the experiments. Samples of partially oxidized particles were collected at 0.2, 0.8, and 0.9 m from the point of entry and analyzed in a QEMSCAN® unit to determine the elemental composition within the population of particles. The distribution of the major elements during oxidation was strongly dependent upon the size and chemical composition of the initial particles. Overall, the copper content tended to increase and sulfur content decreased along the reactor length within all sizes. In contrast, the distribution of iron did not follow a general trend, as it was found to increase, decrease, or remain unchanged depending on the particle size. This finding may represent a key feature to further investigate the reaction path followed by particles during flash smelting, especially those associated with particle fragmentation. In general, the larger the particle size was, the larger the change in the content of the major elements within the particle population. Based on the experimental results, particles within a size fraction of <45 µm tended to follow a reaction path consisting of rapid melting followed by the collision and coalescence of reacting droplets during flight. In contrast, particles within the fraction of 45–53 µm tended to react individually. The oxidation behavior of the unsieved concentrate particles showed a combination of both reaction paths.

Insights into processes and consequent metal(loid) behavior in dredged estuarine sediments upon electrokinetic treatment

The use and reuse of natural and waste materials after treatment has become increasingly crucial as a means of achieving sustainable and environmentally-friendly solutions, and is part of a broader trend towards embracing circular economy principles. This study aims to understand the behavior of different elements (metal(loid)s and non-metals) and minerals during and after electrokinetic remediation (EKR) and to develop an effective approach to monitor its progress and overcome unwanted occurrences. In this regard, estuarine sediments, collected from Tancarville (Seine River estuary, France), were electrokinetically treated using a 64 L laboratory reactor; treatment was done 8 h per day for 21 days. The physico-chemical properties (pH, electric conductivity, and oxido-reduction potential) and current were monitored during treatment. The spatial evolution of the physico-chemical, physical (grain size distribution), mineral (mainly carbonates), organic, and elemental (As, Ca, Cl, Mg, Na, Pb, Sr, Zn, and Zr) characteristics was studied to assess the treatment efficiency. The results showed that the acidic conditions in the anodic sediments caused the dissolution of carbonates (calcite, dolomite, and aragonite), resulting in a considerable reduction in As, Zn, and Pb. Additionally, Cl as well as electric conductivity were significantly reduced from most sediments, which is essential in agricultural practices. Furthermore, materials had precipitated and settled in the anolyte and catholyte chambers, which acted as sorbents for elements that were released from the sediments (mainly Zn and As). Finally, three distinct phases occurred during treatment and were mainly linked to the current intensity and electric conductivity on the one hand, and the dissolution of carbonates and metal(loid) release on the other. This approach can be used to treat sediments and other media to improve the overall efficiency of remediation processes and create an end product with desired characteristics.

Modelling of iron oxide reduction with hydrogen in a small fixed bed

The need to reduce the environmental impact of the steel industry necessitates the development of new production routes that drastically reduce the emissions of carbon dioxide. A potential solution is to change the reductant from carbon monoxide to hydrogen. In the development of such new ironmaking technologies, it is important to understand the iron oxide reduction kinetics under the novel conditions. In this work, a mathematical model of a small fixed-bed reactor was developed using the key assumptions of the Shrinking Core Model to describe the kinetics of the reactive network and mass transport phenomena involved. The model was found to be robust and to perform in a consistent way when subjected to changes in the model parameters and conditions. It was demonstrated to qualitatively reproduce the results of reduction experiments in a small-scale laboratory reactor. Preliminary analysis indicated a promising potential to adapt the model quantitatively to experimental results.

Synthesis of L-Lactide from Lactic Acid and Production of PLA Pellets: Full-Cycle Laboratory-Scale Technology.

Lactide is one of the most popular and promising monomers for the synthesis of biocompatible and biodegradable polylactide and its copolymers. The goal of this work was to carry out a full cycle of polylactide production from lactic acid. Process conditions and ratios of reagents were optimized, and the key properties of the synthesized polymers were investigated. The influence of synthesis conditions and the molecular weight of lactic acid oligomers on the yield of lactide was studied. Lactide polymerization was first carried out in a 500 mL flask and then scaled up and carried out in a 2000 mL laboratory reactor setup with a combined extruder. Initially, the lactic acid solution was concentrated to remove free water; then, the oligomerization and synthesis of lactide were carried out in one flask in the presence of various concentrations of tin octoate catalyst at temperatures from 150 to 210 °C. The yield of lactide was 67-69%. The resulting raw lactide was purified by recrystallization in solvents. The yield of lactide after recrystallization in butyl acetate (selected as the optimal solvent for laboratory purification) was 41.4%. Further, the polymerization of lactide was carried out in a reactor unit at a tin octoate catalyst concentration of 500 ppm. Conversion was 95%; Mw = 228 kDa; and PDI = 1.94. The resulting products were studied by differential scanning calorimetry, NMR spectroscopy and gel permeation chromatography. The resulting polylactide in the form of pellets was obtained using an extruder and a pelletizer.

Transfer of Early-Stage Lithium Recovery from Laboratory-Scale Water Leaching to Upscale Challenges

The early-stage lithium recovery (ESLR) process associates thermal treatment of the black mass from lithium-ion batteries (LIB) with subsequent leaching, especially with water, targeting Li recovery in the first step of the process chain as lithium carbonate. The validation of ESLR has resulted in high Li efficiencies; however, currently, researchers have not yet been established the optimum parameters, which brings uncertainties to a further upscale. Based on that, four parameters, including different black masses previously thermally treated in the industry, were investigated in a leaching step in laboratory scale targeting Li and F leaching efficiencies. Through ANOVA statistical analysis, regression equations of the leaching efficiencies for both elements were generated, which supports an optimization study. The optimum parameters were then transferred to an upscale 100 L leaching trial and evaluated. The results in laboratory scale showed that Li maximization and F minimization were achieved at an S/L ratio of 30 g/L, 80 °C, and 6 L/min of CO2 gas addition, as well as with a sample of bigger particle size and probably more efficient thermal treatment. However, the upscale result with the same parameters showed a lower Li leaching efficiency, which is related to the poor geometric similarity between laboratory and upscale reactors.

Gaseous alkali interactions with ilmenite, manganese oxide and calcium manganite under chemical looping combustion conditions

Alkali species present in biomass pose significant challenges in chemical looping combustion (CLC) processes and other thermal conversion applications. The interactions between different alkali species and three common oxygen carrier (OC) materials that are considered to be state of the art in CLC applications have been investigated. A dedicated fluidized bed laboratory reactor was used to study interactions of KCl, NaCl, KOH, NaOH, K2SO4 and Na2SO4 with manganese oxide, calcium manganite and ilmenite. Alkali vapor was generated by injecting alkali salts under reducing, oxidizing and inert conditions at 900 °C. Gaseous species were measured online downstream of the reactor, and the efficiency of alkali uptake was determined under different conditions. The result show significant alkali uptake by all OCs under the studied conditions. Ilmenite shows near complete alkali uptake in reducing conditions, while manganese oxide and calcium manganite exhibited less effective alkali uptake, but have advantages in terms of fuel conversion and oxidizing efficiency. Alkali chlorides, sulfates and hydroxides show distinctly different behavior, with alkali hydroxides being efficiently captured all three investigate OC materials. The findings contribute to a deeper understanding of alkali behavior and offer valuable guidance for the design and optimization of CLC with biomass.

Leveraging GPT-4 to transform chemistry from paper to practice

We present a two-step prompting approach to streamline literature reproduction, transforming published methods into detailed protocols and then into executable experimental steps for the Mettler Toledo EasyMax automated lab reactor.

Laboratory Reactor Monitoring System Based on IoT

In response to the limitations of existing laboratory reaction vessels, such as the lack of remote monitoring and low level of intelligence, a laboratory reaction vessel monitoring system based on the Internet of Things (IoT) is designed. This monitoring system utilizes a controller with the STM32F407 chip as its core to collect and control the temperature and motor parameters of the reaction vessel. Data exchange with the OneNET cloud platform is facilitated through a WiFi communication module. The remote monitoring terminal establishes a WiFi connection with the OneNET cloud platform, enabling real-time data and command transmission with the STM32F407 controller. Experimental results demonstrate that the system can effectively achieve real-time remote monitoring of the reaction vessel’s operational status, meeting the expected objectives.

The Immobilization of β-Galactosidase on Glass Fiber Rolls

The usability of glass fibers as immobilization support with a porous open structure was investigated. We developed a method to immobilize the enzyme β-galactosidase on special glass fiber rolls. The new method is simple, non-expensive and industrially applicable. Glutaraldehyde was used as a non-specific cross-linking agent for the covalent binding of β-galactosidase on modified glass fibers. The efficiency of immobilization was tested with the known hydrolysis of lactose. All experiments were performed in a continuous laboratory reactor. The influence of the reaction temperature (20, 25 and 30 °C), the substrate flow rate (1, 2 and 3 mL/min) and the pH of the reaction medium (6, 7 and 8) on the conversion was investigated. The reaction efficiency was monitored by measuring the glucose concentration with a spectrophotometer. High immobilization efficiency, enzyme activity and stability were obtained. The optimal reaction temperature, substrate flow rate and pH were found. The activity and stability of the enzyme entrapped on the glass fiber rolls remained almost unchanged during reuse, which is promising for potential industrial applications.

Aggregate Formation by a Microbial Community Developing in a Phosphorus-Removing Laboratory Reactor

Aggregate Formation by a Microbial Community Developing in a Phosphorus-Removing Laboratory Reactor

Design and first application of a novel laboratory reactor for alkali studies in chemical looping applications

Alkali compounds are readily released during biomass conversion and their complex interactions with reactor walls and sampling equipment makes detailed investigations challenging. This study evaluates a novel laboratory-scale fluidized bed reactor for chemical looping combustion (CLC) studies. The reactor design is based on detailed consideration of the behavior of alkali-containing molecules and aerosol particles and is guided by computational fluid dynamic simulations. The design allows for interactions between gaseous alkali and a fluidized bed, while minimizing alkali interactions with walls before and after the fluidized bed. The function of the laboratory reactor is demonstrated in experiments using online gas and alkali analysis. Alkali is continuously fed to the reactor as KOH or KCl aerosol with and without a fluidized bed of the oxygen carrier CaMn0.775Ti0.125Mg0.1O3-δ present in inert, reducing and oxidizing conditions at temperatures up to 900 °C. Alkali uptake by the OC is characterized in all conditions, and observed to sensitively depend on gas composition, reactor temperature and type of alkali compound. The experimental setup is concluded to have a significantly improved functionality compared to a previously used reactor, which opens up for detailed studies of interactions between alkali compounds and oxygen carriers used in CLC.