Industrial & Engineering Chemistry Research最新文献

Hydrogen storage materials are promising as a fuel source for the adaption of a hydrogen-based economy toward more sustainable energy production. An example of such a material is hydrous hydrazine with a hydrogen content of 8.0 wt %. In this study, an iridium-based catalyst was developed via incipient wetness impregnation and used for hydrous hydrazine decomposition in a batch reactor for H₂ generation. The reaction conditions were optimized in a batch reactor, and the results were validated utilizing computational fluid dynamics (CFD). The developed catalyst achieved a yield of over 80% and a TOF value of around 2400 h^–1 at 80 °C. Upon validating the experimental data, CFD studies were performed to provide information on the mixing flow phenomena occurring in the reactor. A different batch reactor configuration was developed, which showcased a lower velocity magnitude compared to the original configuration. Models were developed using a one-dimensional (1D) stirrer and four different shapes of two-dimensional (2D) stirrers. The results among simulations using 1D and the 2D pivot ring stirrer did not vary significantly, validating the accuracy of the model. Given the small reactor size, the effect of a different shape was expected to be negligible; however, the smallest stirrer resulted in a poor mixing profile, highlighting the importance of appropriate mixing. The potential of using a packed-bed microreactor was also simulated. The yield reached a maximum value and then decreased due to the continuous generation of ammonia in addition to hydrogen. The outcomes of this study make a significant contribution to the integration of experimental data with CFD on the decomposition of hydrous hydrazine for catalytic green H₂ generation, highlighting how reactor configurations influence reaction performance and providing insights for scalability on H₂ technologies.

An automated reactor platform was developed using LabVIEW to conduct preplanned experiments for the identification of a kinetic model for the esterification of Levulinic acid (LA) and ethanol over heterogeneous Amberlyst-15 catalyst. A Single Pellet String Reactor of 1.25 aspect ratio was used for this kinetic study, loaded with 0.1 g of 800 μm catalyst spheres, at flow rates 20–60 μL/min, temperatures 70–100 °C, and LA feed concentrations 0.8–1.6 M. An extensive library of power law, Langmuir-Hinshelwood-Hougen-Watson and Eley–Rideal models, was screened through the application of a general procedure for model discrimination and parameter estimation. The procedure, consisting of seven steps, was applied for the investigation of different design spaces and allowed for the reformulation of models to include temperature-dependent parameters, the former leading to an increase in model identifiability and the latter resulting in enhanced model fitting. The combination of experimental data sets including the addition of the reaction product (water) in the reactor inlet stream and the incorporation of temperature dependence in the adsorption coefficients’ expression led to the identification of two suitable kinetic models out of 28 candidates (a Langmuir-Hinshelwood-Hougen-Watson and an Eley–Rideal model), both of which accounted for the adsorption of water on Amberlyst-15 and fitted the experimental data satisfactorily.

Falling film flow significantly enhances devolatilization efficiency in polymer processing, predominantly facilitated by bubble dynamics. The falling film flow characteristics of high-viscosity fluids, the bubble motion, and collapse mechanism in the falling film flow field were investigated numerically and experimentally. The result shows that increased fluid velocity markedly alters bubble morphology, hastening bubble rupture and reducing the time taken for bubbles to reach the liquid film surface. With increasing fluid viscosity, the duration for bubble motion and collapse increases, especially in high-viscosity fluids where the bubble detaches from the liquid film surface, involving growth into a bubble film, followed by rupture near its peak. When the fluid viscosity is 10 Pa·s, the distance from the bubble film peak to the liquid film surface can reach up to 8 mm. Overall, the falling film flow field can promote the removal of bubbles in high-viscosity fluids.

Accurate modeling of density and CO₂ partitioning in the CO₂-water and CO₂-brine systems over a wide pressure and temperature range is of high interest in many subsurface processes. We parametrize a new set of CPA and eCPA equations of state accounting for the CO₂–H₂O cross-association. The CO₂-water phase diagrams and the CO₂ solubility in NaCl brine are reproduced up to 700 K and 6 m of salinity. The density of CO₂ in aqueous mixtures is predicted accurately, including the effect of CO₂ dissolution, which may increase or decrease the density depending on conditions. From Monte Carlo simulations, the SPCE-EPM2 force field with optimized unlike parameters reproduces the high-temperature phase diagram without polarization corrections. In this work, our knowledge of the thermodynamics of CO₂ in aqueous mixtures is expanded by providing a model for geothermal and CO₂ sequestration conditions.

Two million tons per year of distiller waste had been produced by using the bischofite byproducts as raw materials to prepare Mg(OH)₂ through the ammonia method. The distiller waste restricted the development of potassium, lithium, and other resources in Qinghai salt lake in China. In this work, a new green synthesis route of CaMgAl-LDHs using distiller waste as raw materials through a 100% atomic economic reaction route was provided, and the full component of distiller waste was utilized without separation. Pure CaMgAl-LDHs was prepared at 90 °C for 180 min. A reaction mechanism of “dissolution–rapid nucleation–phase boundary reaction process” was revealed. The maximum removal capacity of Pb²⁺ by CaMgAl-LDHs reached 862.5 mg/g. This work realized the efficient utilization of distiller waste with complex components through an atomic economic reaction, providing a new idea for the high-value exploitation of waste resources and the green synthesis of inorganic functional materials.

The separation performance of the CO₂/CH₄ mixture in polymers of intrinsic microporosity (PIMs) is studied by using all-atom molecular dynamics simulations. Eight types of PIMs with different functional groups are considered, namely, cyano, amidoxime, hydroxyl, thioamide, amide, amine, carboxyl, and tetrazole groups. The separation performance of these membranes is mainly controlled by the preferential adsorption of CO₂ over CH₄. PIM with amidoxime (PIM-AO) and amine (PIM-AM) groups are the best two cases. The permeability selectivity of PIM-AO almost exceeds two times that of the original PIM membrane. The good separation performance is attributed to the strong adsorption of CO₂ in membranes because of the interactions of CO₂ molecules with −OH or −NH₂ in amidoxime. In PIM-AM, the interaction strength of CO₂ to the membrane is strong because of the coupling effect of covalent bonding and hydrogen bonding interactions. To give good separation performance, it is suggested to design PIMs with functional groups having strong interactions or multi-interaction sites to CO₂.