Thermal Reactor Research Articles

Process Intensification of the Continuous Synthesis of Bio-Derived Monomers for Sustainable Coatings Using a Taylor Vortex Flow Reactor.

We describe the optimization and scale-up of two consecutive reaction steps in the synthesis of bio-derived alkoxybutenolide monomers that have been reported as potential replacements for acrylate-based coatings (Sci. Adv.2020, 6, eabe0026). These monomers are synthesized by (i) oxidation of furfural with photogenerated singlet oxygen followed by (ii) thermal condensation of the desired 5-hydroxyfuranone intermediate product with an alcohol, a step which until now has involved a lengthy batch reaction. The two steps have been successfully telescoped into a single kilogram-scale process without any need to isolate the 5-hydroxyfuranone between the steps. Our process development involved FTIR reaction monitoring, FTIR data analysis via 2D visualization, and two different photoreactors: (i) a semicontinuous photoreactor based on a modified rotary evaporator, where FTIR and 2D correlation spectroscopy (2D-COS) revealed the loss of the methyl formate coproduct, and (ii) our fully continuous Taylor Vortex photoreactor, which enhanced the mass transfer and permitted the use of near-stoichiometric equivalents of O2. The use of in-line FTIR monitoring and modeling greatly accelerated process optimization in the Vortex reactor. This led to scale-up of the photo-oxidation in 85% yield with a projected productivity of 1.3 kg day-1 and a space-time yield of 0.06 mol day-1 mL-1. Higher productivities could be achieved while sacrificing yield (e.g., 4 kg day-1 at 40% yield). The use of superheated methanol at 200 °C in a pressurized thermal flow reactor accelerated the second step, the thermal condensation of 5-hydroxyfuranone, from a 20 h batch reflux reaction (0.5 L, 85 g) to a space time of <1 min in a reactor only 3 mL in volume operating with projected productivities of >700 g day-1. Proof of concept for telescoping the two steps was established with an overall two-step yield of 67%, producing a process with a projected productivity of 1.1 kg day-1 for the methoxybutenolide monomer without any purification of the 5-hydroxyfuranone intermediate.

Microwave-Assisted dry reforming of toluene as a model tar compound using low-cost iron catalyst for syngas clean-up

Gasification of waste feedstock such as biomass, waste plastics suffers from high tar yields during hydrogen-rich syngas production. The presence of tars result in lower quality syngas, lower syngas yields, reactor blockage, reactor down time, and costly maintenance. Therefore, removal of tar from syngas during gasification is essential. Catalytic reforming of tars via in-situ syngas cleanup is an effective way of mitigating tars. This work explores the possibility of microwave-assisted catalytic dry reforming of tars for syngas production. Due to its chemical complexity, toluene, which is one of the main tar constituents, could be used as a model tar compound. Toluene dry reforming was studied using the Fe/Al2O3 catalyst under CO2 under the temperature range of 400–700 ℃. The toluene reforming reaction was conducted using microwave and conventional thermal reactors. Under microwave irradiation, CO2 and toluene conversions are boosted to 80% at 500 ℃. Hydrogen and carbon monoxide yields were approximately five times and ten times higher in the microwave reactor at 500 ℃, respectively, compared to the productions obtained in the conventional fixed-bed reactor at 700 ℃. Filamentous carbon was also produced as a valuable side product to improve the economy of this process and such value-added carbon was only observed in the microwave reactor. Three reaction pathways were observed during microwave reaction: the toluene decomposition produces an initial hydrogen and carbon deposit on the catalyst; the formation of methane and benzene suggests toluene hydrodemethylation as a secondary reaction; and toluene hydrogenolysis forms light alkanes such as methane, and through reforming reaction under CO2 to syngas.

From simulation to reality: CFD-ML-driven structural optimization and experimental analysis of thermal plasma reactors

Thermal plasma reactors offer an environment of high temperature, enthalpy, and reactivity, making them highly efficient for solid waste treatment and promising for clean energy production from municipal and industrial waste. Optimal geometrical parameters of the reactor can enhance waste treatment and reactor performance. This study presents a comprehensive analysis of 11 key geometrical parameters of a thermal plasma reactor. Utilizing CFD Fluent software, numerical simulations were conducted to generate a dataset. Subsequently, a predictive model focusing on the average temperature in the core melt zone was trained using six Machine Learning (ML) algorithms. The Particle Swarm Optimisation (PSO) algorithm optimized the hyperparameters of the Gradient Booster Regression (GBR) model, which was combined with a Genetic Algorithm (GA) to identify the reactor's optimal geometrical parameters. A DC arc plasma torch-solid waste thermal plasma reactor treatment system was established on this basis. The study also explored the effects of gasification coefficient, reaction temperature, and thermal plasma jet mode on system performance. Findings indicate that the PSO-GBR model achieved the highest prediction accuracy, with the temperature in the core reaction zone reaching 3621 K. The deviation between numerical simulations and machine learning predictions was a mere 1.3%. Enhancing syngas yield and energy efficiency is achievable by controlling reaction temperature and increasing the gasification coefficient. A laminar plasma jet mode, at equal power, provides a more effective reaction environment. The accuracy and reliability of the machine learning-driven regression model and optimization results are significant in guiding the optimal design of plasma reactors and advancing waste-to-energy conversion processes.

Preliminary studies of the MINERVA cryogenic supply system

MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) will be composed of a 600 MeV LINear ACcelerator (LINAC) with a large number of cryomodules and a 100 MW thermal power subcritical nuclear reactor cooled by lead-bismuth. The MINERVA MYRRHA Isotopes productioN coupling the linEar acceleRator to the Versatile proton target fAcility) project is the first phase of the MYRRHA project composed of a 100 MeV, 4 mA continuous-wave proton LINAC. The MINERVA LINAC takes advantage of 60 superconducting radiofrequency (RF) cavities cooled at 2 K by saturated superfluid helium (He II). The MINERVA cryoplant will supply the required cryogenic cooling power of the LINAC through cryogenic lines and cryogenic valve boxes. This paper describes the LINAC cryogenic system supply architecture, the different operating modes, the heat loads, the cryoplant main requirements and the strategy to comply with high reliability requirements. The MINERVA cryoplant shall provide helium flows at 40 K for the thermal shielding, at 5 K for the cooling of the RF couplers and at 2 K for the 60 superconducting cavities installed in 30 cryomodules. The total equivalent refrigeration power of the MINERVA cryoplant is about 3.5 kW at 4.5 K. The cryoplant is composed of a warm compression station including sub-atmospheric volumetric compressors, helium gas storages and a refrigeration cold box with cold centrifugal compressors.

Recent advances in graphene oxide-based electrochemical sensors

Graphene oxide-based nanomaterials are garnering significant attention from various fields due to their unique physical and chemical properties, which make them attractive for myriad applications. This feature article stems from Dr. Aicheng Chen’s Lecture for the 2023 Ricardo Aroca Award of the Canadian Society for Chemistry and focuses primarily on the synthesis and applications of graphene oxide-based nanomaterials for electrochemical sensing. Graphene oxide (GO), reduced graphene oxide, and functionalized and doped GO-based nanomaterials are emerging as promising enablers of broad applications in electrochemical sensors. This is due to their distinctive functional groups and novel properties, which include high electrical conductivities, large surface areas, and enhanced catalytic activities. Several strategies for the synthesis of these nanomaterials are described in this feature article, encompassing the modified Hummers method, electrochemical, thermal, and microwave reactor methods. The characterization of these GO-based nanomaterials is highlighted, employing techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, Raman, and X-ray photoelectron spectroscopy to study their morphologies, structures, and chemical compositions. The development of GO-based electrochemical sensors and their pharmaceutical, medical, environmental, and food safety applications are discussed. Further, the effects of these GO-based nanomaterials and different electrochemical techniques (e.g., cyclic voltammetry, square wave voltammetry, linear sweep voltammetry, and differential pulse voltammetry) on the performance of various electrochemical sensors are addressed.

On the Construction of a Calibration Curve Using a Glow Discharge Emission Spectrometer for Measuring the Hydrogen Content in Zirconium Alloys

One of the main directions of modern activity of metrology researchers is to provide the real sector of the economy of the Russian Federation with reference materials that have no analogues in the country. The article discusses the research of highly efficient materials for fuel cladding (fuel elements) in the active zones of thermal reactors, the scope of which is wide. The purpose of the study is the development of samples of the composition of the zirconium alloy to establish and control the stability of the calibration curves of spectrometers when determining the mass fraction of hydrogen, provided that the metrological and technical characteristics of the reference material meet the requirements of the measurement procedure. The main methods for determining the hydrogen content in materials are analyzed. It has been established that the method of glow discharge optical emission spectroscopy has found the widest application. It has also been established that zirconium alloys are chosen as the main material in most cases.The need to create samples for constructing a calibration curve for spectrometers for measuring the hydrogen content in a zirconium alloy is noted. Samples of zirconium alloy Zr-1Nb (grade Э110) have been developed to construct a calibration curve using a glow discharge emission spectrometer for measurements with a mass fraction of hydrogen from 0.034 to 0.498 %. Calibration is carried out using the developed samples to obtain a calibration curve using the example of an emission glow discharge spectrometer of the GD Profiler2 type. The relative error of the hydrogen mass fraction obtained during calibration does not exceed ± 10 %.The practical significance of the study lies in the development of samples that can be used to calibrate spectrometers based on the method of glow discharge optical emission spectroscopy.

Reductive thermal plasma conversion of a spodumene concentrate and impact on lithium extraction

The conversion of α-spodumene was performed using two different CO2/CH4 thermal reductive plasma reactors. Using one configuration, particle size was proven to have a major role in lithium extraction. Lithium extraction efficiency decreases if the particles are too large. The third phase γ-spodumene is less reactive than β-spodumene and has a negative effect on lithium extraction. The other configuration showed that thermal plasmas were able to perform spodumene conversion with results close to that of traditional heating methods, electrical heating or gas burners. Thermal plasmas were proven to decrepitate coarse particles into micrometric particles with a lithium content increase in lower sized fractions. The lithium extraction was proven to be possible on plasma converted samples with lithium extraction efficiencies similar to that of classical heating methods for the lower sized fractions. This means that thermal plasmas could be used to replace CO2 and NOx emitting heating methods such as gas burners in spodumene conversion with similar results while consuming harmful gases instead of producing them, reducing the environmental impact of the process.

Effect analysis of oxide layer on thermal hydraulic characteristics of LBE cooled reactor

For Lead-Bismuth Eutectic (LBE) alloy cooled reactor, oxidation corrosion is very important and would affect the thermal hydraulic characteristics of the reactor. In this paper, based on LETHAC code developed by Xi’an Jiaotong University (XJTU) for system level thermal hydraulic analysis LBE reactor, a simulation module for oxidation corrosion is developed and added. The influence of oxidation layer on the heat transfer characteristics of the reactor is conducted. Based on LESMOR reactor designed by XJTU, a simulation calculation is carried out under the long-term operation conditions of the reactor considering the growth of oxidation layer. The distribution of the oxide layer in the reactor, the change of temperature appreciation caused by the oxide layer over time and the distribution in the reactor are obtained. The presence of oxide layer will affect the fluid temperature and wall temperature of reactor. The longer the run time, the greater the impact. This paper could provide solid analysis methodology reference for the design of LBE reactor.

Analysis of radwaste accumulation in various scenarios of NP development

Within the framework of “Proryv” project a radiation-equivalent approach to radioactive waste management is being envisioned with U and Pu recycling and MA transmutation. Successful industry-wide implementation of the design approaches should be planned in order to avoid considerable financial and radiological encumbrances caused by the NFC final stage for two-component nuclear power system (NPS) under formation on the basis of thermal and fast reactors. In order to ensure a successful industry-wide implementation of the approaches being developed, the back-end of the NFC should not constitute considerable a financial and radiological burden for the emerging two-component nuclear power system (NPS). This article addresses the problems concerning justification of radiological and technical-and-economic feasibility of MA partitioning and subsequent transmutation in FNR. The extent of MA accumulation as a result of TNR SNF reprocessing confirms the need for the introduction of MA partitioning technologies not only at all reprocessing plants planned for commissioning, but also at the plants now in operation. Based on available data, the study has shown that the implementation of the closed NFC with FNR contributes to significant reduction in the cost of disposal of radwaste compared to the scenario based exclusively on the development of VVER and open fuel cycle technologies. Recycling plutonium in fast reactors should be implemented in conjunction with MA to address environmental, non-proliferation and economic concerns of the back-end of advanced NFC. Within the scale of the future nuclear power system in Russia, an option such as this can only be realized on the basis of developing a FNR fleet.

Analysis of configurational factors that influence the reversibility of nonstoichiometric countercurrent thermal reduction reactors

Recently, thermodynamic modeling has demonstrated that reduction of nonstoichiometric oxides in a counterflow gas current with a single inlet and exit must result in an equilibrium temperature gradient that deviates from the typically assumed isothermal operation at every single point but one, under assumed mass balance constraints. This necessity for a temperature gradient results in real processes that are near isothermal to deviate from the ideal reversible process, except for the single point where the Gibbs free energy change is zero. In this paper, new configurations with additional inlets and exits that can better approximate reversible and isothermal countercurrent flow reactors are considered and thermodynamically modeled. We show that it is possible to decrease irreversibilities while operating under the same maximum temperature, gas flowrates and initial nonstoichiometry simply by employing two or more exits and/or inlets. Under the most optimal conditions where the normalized irreversibilities are lowest, utilizing either an extra exit or extra inlet and exit show improved results in terms of minimizing the Gibbs free energy and lowering the needed separation work for the gases. Generally, as more irreversibilities are generated within the reactor, the more significant the usage of extra inlets/exits becomes.

Multiphysics and multi-scale design and analysis of nuclear thermal propulsion pellet bed reactor based on spherical cermet fuel element

Due to the advantages of high thrust and high specific impulse, nuclear thermal propulsion (NTP) is a preferred near-term rocket engine technology for future Mars missions. This article introduces the reactor design based on spherical cermet fuel element, with the aim of studying the feasibility of applying this new fuel in NTP system. First, design requirements are determined based on the unique features of NTP. In terms of neutronics, the effect of rocket launch accidents and fuel loss caused by high-temperature hydrogen are considered. Thermal hydraulics refer to the requirements of NASA's Mars Design Reference Architecture 5.0 (DRA 5.0) for impulse, thrust, and thrust to weight ratio. Second, based on the requirements above, the optimal reactor configuration parameters are obtained with the goal of maximizing the thrust to weight ratio: reactor radius 51.1 cm, height 106 cm, aspect ratio 1.04, reflector 13 cm, and reactor mass 3940 kg. Finally, the performances of the optimal reactor design are analyzed. The neutron spectrum shows a characteristic of fast neutron spectrum, and fuel loss analysis shows that the core can withstand a fuel mass loss of about 4 wt%. In addition, the core axial and radial power distribution are calculated, with an overall power peak factor of 1.26. The thermal hydraulic calculation provides a range of core operating conditions that satisfy the design requirements of DRA 5.0 and temperature, with power of 620 ∼ 950 MW and flow rate of 16 ∼ 24 kg/s. Compared with the ANL200/2000 reactor using prismatic cermet, it has the advantage of higher specific impulse. The main disadvantage is the large pressure drop, which prevents it from being applied to the scenarios of high power and high thrust. Therefore, for NTP reactor using spherical cermet elements, it should be applied to low to medium power scenarios.

Effective Multiplication Factor Analysis of Gas-cooled Reactor using OpenMC code with ENDF/B-VII.1, ENDF/B-VIII.0 and JENDL-5.0 Nuclear Data

As the demand for nuclear energy keeps rising, Generation IV reactor designs continuously improve. One such potential reactor design is the Gas-cooled Reactor. Neutronic analysis is the foundation for ongoing design modifications and alternatives for the Helium Gas-cooled Reactor. An important aspect of neutronic analysis is the nuclear data library. This research compares how different nuclear data libraries impact a Helium Gas-cooled Reactor design by comparing the neutron effective multiplication factor (k-eff) value. This research was conducted by the Monte Carlo method using OpenMC code. ENDF/B-VII.1, ENDF/B-VIII.0 and JENDL-5.0 were used as nuclear data libraries to simulate the reactor design for ten years of depletion time with 1-year timesteps. The reactor is designed in two different spectrums: the fast neutron spectrum design and the thermal neutron spectrum design. The differences between the two designs are in the cladding and reflector materials where the thermal neutron spectrum uses graphite moderator. The results for thermal spectrum design show that while each nuclear data library’s average k-eff values vary, they all produce the same results at timestep zero, with k-eff values around 1.02500. The average k-eff value from simulation using the ENDF/B-VII.1 library is 1.01477, the average k-eff value from simulation using the ENDF/B-VIII.0 library is 1.01122, and the average k-eff value from simulation using the JENDL-5.0 library is 1.01047. Each simulation result has an average uncertainty of 0.00040. The difference is due to the different amounts of data in each library. JENDL-5.0 has the highest amount of data inside its nuclear libraries, followed by ENDF/B-VIII.0 and ENDF/B-VII.1. Meanwhile, the average difference between the different libraries is insignificant for the thermal gas-cooled reactor simulation results. ENDF/B-VIII.0 produces an effective k-average of 1.04437, and JENDL-5.0 produces an effective k-average of 1.04273. Mass change over time results also shows that the transmutation of Uranium-238 into Plutonium-239 occurred. The fast spectrum reactor design shows a greater increase in plutonium-239 than the thermal spectrum design. The three libraries used did not show large differences in results in calculating changes in the mass of Uranium-238 over time due to Uranium-238‘s large mass, but they still showed differences in Plutonium-239‘s mass change over time. The average value difference between libraries in the fast neutron spectrum reactor design is 50 kg, and in the thermal spectrum it is 30 kg.

Assessment of radiation environmental risks for fish fauna of the cooling pools of a number of operating nuclear power plants

Relevance. The need to assess radiation risks for the main types of fish in pools that are under the constant influence of the nuclear power plants. Aim. To assess the radiation environmental risks for the ichthyofauna of cooling pools of the operating nuclear power plants, to analyze the sources and features of formation of the radiation risks at different stages of their operation. Objects: monitoring studies of radiation environmental risks for reference fish species in cooling reservoirs of the Leningrad, Beloyarsk and Novovoronezh NPP. Methods. Calculation of the exposure dose rate and quantitative assessment of the risk of exposure to technogenic radionuclides of the ichthyofauna of the cooling pools of the Beloyarskaya, Leningradskaya and Novovoronezhskaya NPPs were carried out using the international computer complex of the updated version of ERICA Tool 2.0. Results. The paper demonstrates that the radiation ecological risks for the ichthyofauna in the cooling pools of the operating nuclear power plants are caused by the combined effect of radioisotopes of the different origin. The features of the formation of the radiation risks for each pool are specific and depend on the current radiation situation. The cooling pool of the Beloyarskaya NPP is characterized by a pronounced dependence of the radiation load on the types of operating power units. The ichthyofauna experienced the greatest radiation risks during the operation of the first two power units with thermal reactors AMB-100 and AMB-200. The decommissioning of the first power units and the construction of the units with the fast neutron reactors (BN-600 and BN-800) led to a significant reduction in the radiation load on the ichthyofauna of the cooling pool. At present, the radiation risks are caused mainly by the influence of 90Sr, which is almost not discharged from the Beloyarskaya NPP into the cooling pools, but has a predominantly global origin. Therefore, the formation of the risks is more associated with atmospheric fallout of 90Sr, and not with the operation of the nuclear power plant. The radiation risks for the ichthyofauna of the Leningradskaya NPP cooling pool are caused by the combined effect of 137Cs as a result of the radiation accident at the Chernobylskaya NPP and radionuclides with induced activity (14C; 60Co; 3H 54Mn and 65Zn), the origin of which may be associated with the operation of the nuclear reactors of the NPP. The level of radiation risk for the fish fauna of the Novovoronezhskaya NPP cooling pool for 2009–2019 increased 2.2 times due to an increase in the content of 60Co in many components of the pool. As a result, 81.7% of the radiation risks in demersal fish species were formed by the influence of 60Co. It cannot be ruled out that the increase in the 60Co content in the cooling pool of the Novovoronezhskaya NPP is a consequence of radioactive contamination of the groundwater as a result of the 1985 accident. The ecological risks for the fish fauna in all cooling pools are two to three orders of magnitude lower than the maximum allowable hazard coefficient. Thus, the normal operation of the nuclear power plants does not create unacceptable radiation risks that pose a real environmental threat to the fish fauna of the cooling pools.

Order-of-Magnitude Increase in Carbon Nanotube Yield Based on Modeling Transient Diffusion and Outgassing of Water From Reactor Walls

Abstract While reactor wall preconditioning was previously shown to influence the yield in chemical vapor deposition (CVD), especially for the growth of carbon nanotubes (CNTs), it was limited to studying accumulating carbonaceous deposits over a number of runs. However, the effects of temperature and duration as the reactor walls are exposed to hot humidity for extended periods between growth runs were not previously studied systematically. Here, we combine experimental measurements with a mathematical model to elucidate how the thermochemical history of reactor walls impacts growth yield, especially knowing that only a specific range of humidity promotes growth. Importantly, we demonstrate a one-order-of-magnitude higher CNT yield by increasing the interim, i.e., the time between runs. We explain the results based on previously unexplored process sensitivity to trace amounts of oxygen-containing species in the reactor. In particular, we model the effect of small amounts of water vapor being desorbed from reactor walls during growth. Our results reveal the outgassing dynamics and show the underlying mechanism of generating growth-promoting molecules. By installing a humidity sensor in our custom-designed multizone rapid thermal CVD reactor, we are able to uniquely correlate the amount of moisture within the reactor to real-time measurements of growth kinetics, as well as ex situ characterization of CNT alignment and atomic defects. Our findings enable a scientifically grounded approach toward both boosting growth yield and improving its consistency by reducing run-to-run variations. Accordingly, engineered dynamics recipes with added preprocessing steps can be envisioned to leverage this phenomenon for improving manufacturing process scalability and robustness.

Neutronic Design Modification of Passive Compact-Molten Salt Reactor

Passive compact molten salt reactor (PCMSR) is a design concept of a molten salt reactor (MSR) currently under development in Universitas Gadjah Mada, Indonesia. It is designed as a thermal breeder reactor using thorium fuel cycle. However, our previous study shows that the original PCMSR design was incorrectly modelled, primarily overestimating its thorium breeding capability. To improve PCMSR neutronic design, we modified the core configuration by the addition of radial fuel channel layers previously nonexistent in original PCMSR core design in various configurations. Neutronic parameters of modified PCMSR geometries in the beginning of life (BOL) were simulated using MCNP6.2 radiation transport code with ENDF/B-VII.0 library. All variations of fuel layer addition show improvement in both temperature coefficient of reactivity (TCR) and breeding ratio (BR), with TCR values became more negative and BR values are larger than unity, ensuring proper breeding capability. Configuration Inner Core-Outer Blanket (IC-OB) achieves the largest BR and lowest doubling time (DT), whilst its TCR is an improvement from the original design. Therefore, IC-OB fuel layer configuration can be applied to redesign the original PCMSR and used in various design optimization scenarios.

Environmentally sustainable ethyl levulinate synthesis from delignified sugarcane bagasse using ternary eutectic solvent under MW-xenon irradiation: engine performance and emission assessment.

For the first time, a synergistic energy-efficient combination of microwave-xenon (MW-XE) irradiations in presence of photoactive ternary acidic deep eutectic solvents (TADES) has been applied for intensification of ethyl levulinate synthesis from delignified sugarcane bagasse (DSB) under mild (90min, 90°C) and environmentally benign process conditions. The Taguchi orthogonal designed optimized conditions (20 W/cm3 of MW specific irradiation power input, 1 mol/mol of FeCl3 to citric acid ratio, 90min of reaction time, 150 W of XE specific power input) rendered maximum 61.3mol% of EL yield (selectivity: 87.70 [Formula: see text] 0.5%). Remarkably, synergistic effect of MW and XE irradiation significantly enhanced the EL yield (61.3mol%) compared to the individual MW (34.52mol%) and XE (22.67mol%) irradiation at otherwise optimized reaction conditions. Moreover, the MWXE irradiated reactor (MWXER) exhibited a significant 79.10% increase in EL yield compared to the conventional thermal reactor (CTR), at the expense of 10% less energy consumption. The ethyl levulinate could be recovered efficiently through green protocol from reaction mix resulting in high purity (97 [Formula: see text] 0.5%) and TADES was sustainably reused in the process. The optimally generated product EL when blended (5 and 10 vol.%) with B10 and B20 (10% and 20% biodiesel-diesel blend) could provide 21-31% reduction in HC and 7.3-36% reduction in CO in comparison with petro-diesel. It was also explored that, at similar optimal parametric combinations, the TADES produced 29.5% greater EL yield in comparison with the standard ionic liquid BMIMCl. The life cycle environmental impact analysis (LCEIA) of the overall process revealed that the 5 vol.% EL blending with B10 contributed lowest environmental impacts mitigating marine ecotoxicity, human toxicity, fossil depletion, and climate change by 77.9%, 77.4%, 78.4% and 77.5%, respectively.

The RAPTR furnace: a rapid heating and cooling sample furnace for in situ X-ray scattering studies of temperature-induced reactions

In situ X-ray scattering provides valuable insights into the mechanisms and kinetics of reactions and structural transformations. For reactions and structural transformations primarily driven by temperature, and not coupled to chemical/electrochemical triggers, our ability to initiate and quench processes thermally is a practical limit for probing fast reactive phenomena. Meaningful quantitative analysis requires the dynamic phenomena to be triggered on fast time scales relative to the reaction/transformation kinetics. This article describes a new sample furnace, the Rapid-Actuating Pneumatic Thermal Reactor or RAPTR, for time-resolved in situ X-ray scattering studies initiated by temperature. The RAPTR quickly heats and cools samples by translating them into and out of a pre-heated hot zone. Using diffraction thermometry, it is shown that the samples can be heated/cooled in 10 s or less, with temperatures up to ∼1000°C being accessible. The application of the RAPTR furnace is demonstrated by exploring a fast solid-state reaction: the synthesis of scheelite-type lead tungstate, PbWO4, from PbO and WO3 for which Pb3WO6 is identified as a previously unrecognized reaction intermediate.

A comparison between Claus and THIOPAQ sulfur recovery techniques in natural gas plants

A sulfur recovery process is one of the most important processes in the oil and gas industry to get rid of hydrogen sulfide (H2S) which is produced from the acid gas removal process of sour natural gas to convert it into sweet natural gas. Actual data from a gas field is used to obtain a realistic comparison between two sulfur recovery techniques, through which researchers and/or manufacturers can obtain information that will help them choose the most appropriate and cheapest method. A total feed acid gas flow rate of 5.1844 MMSCFD with an H2S concentration of 24.62% by mole percent was produced from amine acid gas removal units. Claus sulfur recovery technique is a traditional chemical process that uses thermal and catalytic reactors. Therefore, an acid gas enrichment unit is applied to increase the H2S concentration to approximately 50% mole to provide reliable and flexible operation in the thermal and catalytic reactors. Moreover, a tail gas treatment unit is applied to increase the overall conversion efficiency to 99.90% with the Claus technique instead of 95.08% without it to achieve high sulfur recovery and reliable operation through the conversion of carbonyl sulfide (COS) and mercaptans. Studies on the safety and simplicity of the Claus technique revealed many important hazards and a large number of transmitters (379) and control loops (128) in one Claus train. THIOPAQ sulfur recovery as a new technology is a biological desulfurization process that uses a natural mixture of sulfide-oxidizing bacteria. It is also a unique H2S removal process with an efficiency of 99.999%. In addition, studies on the safety and simplicity of the THIOPAQ technique have shown that the hazards, the number of transmitters (74), and the number of control loops (29) of a one THIOPAQ train are lower. The THIOPAQ technique showed higher efficiency, was safer, simpler, and had lower CAPEX and OPEX. This study was conducted using Aspen HYSYS V11 and actual data.

INTERVAL MODEL FOR ASSESSING THE PURITY OF NUCLEAR STRUCTURAL METALS BY MICROHARDNESS

The article considers the possibilities of evaluating the purity of Zr-1%Nb zirconium alloy samples – the main structural material of the thermal neutron reactors active zones with a water coolant – according to the microhardness of the metal. The correctness of the application of interval regression analysis is shown, if there is uncertainty, incompleteness of information, measurement errors in the experimental data for determining the oxygen content in metal samples and its microhardness. The method of estimating parameters of interval linear regression is presented.

Effects of Arrhenius kinetic on the magnetized nanofluid flow through a porous stretchable cylinder with slip conditions

ABSTRACT This research addresses the implications of slip on the magnetohydrodynamic transport properties of Newtonian nanofluids. The study employs Buongiorno’s theoretical framework and focuses its attention on a cylindrical object that experiences tensile deformation inside a medium characterized by porosity. In contrast to the often observed boundary conditions that presume a constant temperature and concentration, the current research utilizes hydrodynamic and thermal slip conditions. The recognition of many significant elements, including the Arrhenius activation energy, magnetic field, and viscous dissipation, also has important significance. The phenomena of interest pertaining to fluid flow is first defined and afterward converted into a nondimensional form by including relevant commonalities. In order to do a thorough examination of the current situation, the shooting algorithm and the bvp 4 c technique are used. Graphical and tabular representations are used to demonstrate the implications of several emerging features on the velocity, temperature, and dispersion of nanoparticles. The observed data suggests that a rise in chemical reaction parameters leads to a drop in nanoparticle concentration distributions, but the activation energy parameter exhibits an opposite tendency. It is discovered that the boundary layer thickness under slip flow circumstances differs from that seen without slip flow. The Sherwood number rises when the chemical reaction parameter gets higher, whereas the activation energy parameter escalates in the opposite direction. The present research covers a broad variety of applied sciences applications, with a special emphasis on thermal oil recovery, geothermal reservoirs, chemical engineering, and nuclear reactor cooling.