Theoretical Foundations of Chemical Engineering最新文献

Hydrometallurgical methods remain among the most promising for lithium-ion battery recycling, and liquid–liquid extraction is the key step in separating the complex mixture of elements that make up the anode and cathode. The development and complication of the composition of batteries, in particular, the active production of lithium titanate anodes, requires additional research on extraction. The work studied in detail the extraction of Ti(IV) ions with the Aliquat 336–menthol hydrophobic deep eutectic solvent, which was previously successfully used to separate elements from leaching solutions of NMC-type cathodes (LiNiMnCoO₂). Data were obtained on the extraction of titanium(IV) ions with varying acidity of the medium, concentration of chloride ions, and concentration of the extractant in the deep eutectic solvent. Based on these data, a mechanism for the extraction of titanium(IV) ions was proposed. Finally, a system for efficient extractant regeneration was proposed. The result of this work can be used to create an extraction scheme for separating leaching solutions of lithium-ion batteries with a lithium titanate anode.

Biomass gasification technology is used as one of the energy sources due to its low effects on the environment and reducing pollution. This technology is able to produce gas with the highest content of hydrogen. Hydrogen can be used as a fuel and an important carrier of energy due to its stability and lack of negative effects on the environment. This study used wood sawdust as biomass to produce syngas and investigated the effect of adding carbon dioxide and methane gases to the Gibbs reactor. Aspen Plus software is used for steam gasification modelling. According to the results, the performed modelling is able to predict the experimental data well. When the carbon dioxide to biomass ratio (C/B) rises, the mass flow rates (MFR) of hydrogen and Methane fall while those of carbon dioxide and carbon monoxide increase. The decrease in hydrogen MFR with changes from C/B = 0 to C/B = 1 in modes a, b, c and d is equal to 17.51, 16.39, 29.57 and 24.84%, respectively. The mass flow of hydrogen increases as the Methane to biomass ratio (M/B) rises, whereas the MFR of carbon dioxide shows a declining pattern. As M/B increases from 0 to 1 in the Gibbs reactor for modes a, b, c and d, the hydrogen MFR increases by 265, 243, 297 and 305%, respectively.

In this paper, the effects of the number of fuel additions, pot size and the size of the primary air outlets on the thermal performance and pollutant emission of cooking stoves were investigated, based on which the response surface test was designed and parameter optimization was carried out. The results showed that: the order of the main and secondary factors affecting the thermal efficiency was as follows: B-pot size > C‑primary air ratio > A-fuel additions; the order of the main and secondary factors affecting the SO₂ emission was as follows: B-pot size > A-fuel additions > C-primary air ratio. Through the combination of the highest thermal efficiency and the lowest SO₂ emission factors: when the number of fuel additions is 4 times, the size of the iron pot is 18 cm, and the proportion of the primary air is 63.5%, the thermal efficiency is 31.13%, and the amount of SO₂ released is 6.79 mg. This study provides a reference for the biomass cooking stoves to achieve the purpose of reducing the waste of fuel and reducing the emission of pollutants.

Physical–chemical data on the liquid–solid phase transitions in the binary systems trans-perfluorodecalin (trans-PFD)–cis-perfluorodecalin (cis-PFD), trans-PFD–perfluorobutylcyclohexane (BCH), and cis-PFD–BCH are obtained. All three systems are characterized by the presence of a temperature extremum on the fusibility curve. For the trans-PFD–BCH system, the liquidus line can be described by the equation for simple eutectic systems with the assumed activity coefficient (gamma _{i}^{l}) = 1, which indicates that the behavior of the system is close to ideal. The process of bulk crystallization is considered using the example of a cis‑PFD–BCH mixture. It is demonstrated that from cis-PFD–BCH mixtures with an initial content x_cis-PFD = 0.7348 and 0.6447 mol. fr., cis-PFD can be isolated with a purity of more than 0.99 mol. fr. in three crystallization cycles.

A novel class of therapeutic agents, the sodium-glucose co-transporter 2 (SGLT2) inhibitors, is emerging as a promising avenue for type 2 diabetes management. A dataset comprising 1807 SGLT2 inhibitors was subjected to a quantitative structure-activity relationship (QSAR) investigation using the AutoQSAR module of Schrodinger Maestro 12.8. Of these compounds, 1355 were designated as the training set for model development, followed by comprehensive evaluation through a battery of internal and external cross-validation techniques. Subsequently, a subset of 452 compounds served as an independent test set for external validation. The resultant QSAR model exhibited promising statistical performance, as evidenced by the calculated predicted R² and Q² values, at 0.873 and 0.781, respectively. Furthermore, the predictive correlation coefficient attained a commendable value of 0.84. Notably, this model demonstrates its efficacy in forecasting inhibitory activity and furnishes valuable insights that can be harnessed for the design of novel SGLT2 inhibitors in future endeavors.

This paper is dedicated to deal with thermosolutal natural convection within an enclosure submitted to destabilizing heat and mass fluxes and confining an electrically conducting binary mixture. The cavity is bathed in an external magnetic field and Soret and Dufour effects are considered. An approximate analytical solution is derived, valid in the limit of a shallow enclosure and confirmed numerically by using a finite difference method. The results show the existence of six regions in (left( {{text{Du}}{kern 1pt} --{kern 1pt} {text{Sr}}} right)) plane describing different flow behaviours. The critical Hartman number and critical inclination of magnetic field, which lead to the suppression of convective flows are calculated analytically vs. the control parameters. The obtained results illustrate a significant impact of the combined effects of the inclined magnetic field (via its intensity and inclination) and the Soret and Dufour parameters on different thresholds of convection and the resulting heat and mass transfer. Moreover, the increase in the inclination of the magnetic field in the range ({{0 < theta < frac{pi }{2}} mathord{left/ {vphantom {{0 < theta < frac{pi }{2}} {left( {frac{pi }{2} < theta < pi } right)}}} right. kern-0em} {left( {frac{pi }{2} < theta < pi } right)}}) has a stabilizing/(destabilizing) effect with respect to stationary and sub-critical convections, regardless of the Hartmann number.

In this study, sulfide removal was carried out in the Electrocoagulation process under controlled and uncontrolled pH conditions. Under optimum conditions, electrocoagulation took place in less than 40 minutes at uncontrolled pH and less than 30 minutes at controlled pH to reduce the sulfite concentration of the effluent below 0.5 mg/L. The reaction rate constant and iron-sulfide molar ratio for sulfide removal were 14.09 × 10^–2 min^–1 and 0.97 mol/mol, respectively; under uncontrolled pH conditions, they were 22.88 × 10^–2 and 0.97 mol/mol at controlled pH. The mg sulfide removed per g Fe was calculated as 654.0 mg S^2–/g Fe at uncontrolled pH and 508.46 mg S^2–/g Fe at controlled pH. The operating costs for uncontrolled and controlled pH conditions were also calculated as 2.063 $/m³ (0.747 $/kg S) and 0.842 $/m³ (0.628 $/kg S), respectively. Controlled pH conditions were important in sulfide removal by the Electrocoagulation process.

The undesirable presence of the gas bubbles negatively affects the expected properties (strength, molding and etc.) of a liquid polymer in some industrial products. Therefore, the development of the degassing methods is becoming an important industrial issue. The vibration is one of the most effective degassing approaches but still little researches have published in order to improve this method characters. The current study has investigated the rheological and thermophysical properties of a non-Newtonian polymer liquid in the bubble removal process to find the optimum properties of vibration. Therefore, a mathematical correlation has attained between the vibration and a non-Newtonian fluid properties. Also, the results show that in a viscoplastic fluid, the vibrational deflation ratio is slightly sensitive to the yield stress and by increasing the fluid surface tension from 0.03 to 0.07 N/m, the vibration bubble-desalination ratio increases by 10.6 times. As well as decreasing the fluid stability index from 0.30 to 0.50 results the increase in the bubbling ratio by 14.47%. However, by increasing the flow index from 0.30 to 0.50, due to the decrease in fluid thinning property, the final bubble velocity decreases by 48.27%.

The failure of one node may cause the cascade failure, resulting in the failure of the chemical whole system. Robustness analysis of network is an effective means to prevent cascade failure. When analyzing robustness, predecessors only considered single chemical complex network, such as chemical material network and control system network. However, there is coupling between different networks. Therefore, this paper considers the coupling between networks, and a robustness analysis model of asymmetric chemical coupling network based on asymmetric dependent network model is proposed. In this paper, seven coupling dependency and two connection modes are considered, and the influence of coupling dependence and node connection modes on the robustness of network is explored. The results of the case show that the model is feasible and can well analyze the network robustness of chemical process under two types of network coupling conditions, which provides a theoretical basis for avoiding cascade failure propagation.

Literature analysis shows that the main method to model the equilibrium characteristics of reaction systems at elevated pressures, including processes under supercritical conditions, are equations of state describing the non-ideality of the vapor and liquid phases, while the law of mass action is applied to describe the kinetics of the elementary and chemical stages. The mentioned difference in the types of models used to describe the equilibrium and kinetic characteristics of the same experimental system under study violates the second law of thermodynamics formulated by Clausius. The only theoretical method consistent with the second law of thermodynamics is the molecular theory based on the lattice gas model. In order to satisfy the second law of thermodynamics, molecular models must provide the self-consistent description of the rates of the chemical process at the equilibrium and elementary stages. This means that the molecular models must provide a single mathematical apparatus to calculate the states of the system both outside and inside the equilibrium point. The molecular models can differ in both the effective parameters of the interparticle interaction and the methods of refining these models due to taking into account distinctions in sizes, contributions of the vibrational motions of the components, as well as the accuracy of description of the correlation effects. To ensure the self-consistent description of the equilibrium and kinetics, the models must at least reflect the effects of direct correlations. One-particle approximations (mean field, chaotic, density functional) do not correspond to the self-consistency condition and violate the second law of thermodynamics.