查看更多>>摘要：Based on a lumped methanol-to-olefins (MTO) reaction kinetic model over SAPO-34 catalyst particles, a one-dimensional two-phase model was developed for bubbling fluidized bed reactor and catalyst regenerator. Comparison of the model predictions with literature experimental data showed good agreement over wide ranges of operating conditions both on a bench-scale unsteady-state bubbling fluidized bed reactor as well as pilot and demo-scale steady-state dual fluidized bed reactor-regenerator. The two-phase reactor model was also applied for catalyst coke content combustion with diluted air to design the regenerator of the dual fluidized bed reactor. Finally, the heat duty required for cooling circulating catalyst particles is obtained from overall energy balances. This integrated reactorregenerator simulation allows for seamless analysis of MTO process. The trade-off between the complexity and applicability of the model makes it a useful choice for conceptual process designs, scale-up, integration with simulation software, optimization, process control and economic analyses. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Bio-ethyl lactate (EL), an alternative green solvent to the traditional petroleum-based solvent, has a distinct advantage in the chemical industry. However, to solve the problem of high energy consumption and low yield in the production of EL is the premise of large-scale production and application. This work proposes an economical and energy-efficient reactive distillation (RD) process through excess lactic acid (LA). As the primary data of RD process design, the kinetics of esterification reaction between LA and EL were investigated using the ion exchange resins KRD001 catalyst. Besides, the developed RD model has been validated utilizing five pilot-scale RD experimental data for process design. Furthermore, the proposed process is optimized with the objective of the minimum heat duty per kilogram product (HDP) of EL, taking into account energy consumption, reaction conversion, economic and environmental impacts. The proposed process has obvious economic and environmental advantages, which can cause a reduction of 52.25% for the total annual cost per kilogram product () of EL and 4.63% for the gas emissions compared with the excess ethanol (EtOH) process. This provides guidance and reference for the green technology development and production of EL. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：Many recent attempts to commercialize bio-succinic acid (bio-SA) ended to be unsuccessful after a start flourishing moment. Furthermore, the improved environmental performance of bio-SA production processes compared to petroleum-based SA is still uncertain. In this study a techno-economic analysis was conducted comparing four bio-SA manufacturing processes in terms of net present value and minimum selling price. Two of the simulated processes are based on patents released by bio-SA manufacturing companies (I) Roquette/DSM (Reverdia) and (II) DNP Green Technology/ARD (BioAmber). A third process is based on a Michigan State University patent (III) and a fourth process is conceptual (IV). The conceptual process IV was demonstrated to have <50% lower capital costs and similar to 40 to 55% lower manufacturing costs than the other processes. With a minimum selling price of 1.4 USD kg(-1), process IV would be cheaper than petroleum based succinic acid (similar to 2.0 USD kg(-1)). The Reverdia-based process can also be competitive, while process III and particularly the BioAmber-based process II are not profitable. Ion-exchange columns, nanofiltration and anion exchange membranes are shown to be key technologies for lowering bio-SA manufacturing costs. Continuous bio-SA fermentation with in situ-like extraction can changethe bio-SA market, but the environmental sustainability assessment reveals only marginaldifferences compared with petroleum-based SA. Low pH "aerobic fermentation" is likely to be a more sustainable strategy compared to neutral pH "aerobic fermentation". (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Institution of ChemicalEngineers. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).
Bangi, Mohammed Saad FaizanKao, KatyKwon, Joseph Sang-Il
9页
查看更多>>摘要：beta-Carotene has a positive impact on human health as a precursor of vitamin A. Building a kinetic model for its production using Saccharomyces cerevisiae in a batch fermentation process is challenging as it is difficult to quantify all the complex phenomena within the process. Any knowledge gap in the kinetic model can be reduced by utilizing data. Therefore, in this work, a hybrid model is built using the universal differential equations (UDEs) approach for accurately approximating the unknown dynamics of the process and thereby, increasing the overall accuracy of the model. In UDE approach, a neural ordinary differential equation that approximates the derivatives of the previously unknown dynamics of the batch fermentation process is integrated with the ODEs of its kinetic model to give a hybrid model with superior accuracy. Additionally, prior knowledge about the process is incorporated during the hybrid model training to ensure faster convergence of its parameters. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Yeardley, Aaron S.Milton, Robert A.Moghadam, Peyman Z.Cordiner, Joan...
11页
查看更多>>摘要：To date over 80,000 metal-organic framework (MOF) structures have been synthesised and only ca. 3% of these have had their adsorption capabilities measured for storing oxygen alone. As such, in order to aid the process of producing top-performing MOFs for storing various gases, accurate methods to predict the deliverable capacity of MOFs that have their synthesis method already known is increasingly important. For this purpose, this paper develops a reduced order model (ROM) that can predict the deliverable capacity of synthesised MOFs irrespective to the storage gas across similar gases. The ROM is constructed by identifying the active subspaces through a Sobol' index-based global sensitivity analysis (GSA). The resulting Gaussian process (GP) regression model efficiently predicts the deliverable capacity given a MOFs pore properties with this reduced dimensional space. This approach was applied to a practical MOF exploration example by training a ROM with 2745 MOFs storing methane at 30 bar. The ROM was robustly tested and analysed before using it to predict the deliverable capacity of 82,221 synthesised MOFs storing oxygen at 30 bar. To ensure validity in the exploration example, the predictions produced from the methane trained ROM were compared to a separate ROM trained using the same MOFs but storing oxygen gas. The methane trained ROM was found to be in agreement with the oxygen trained ROM, and was shown to be a viable tool to identify the top-performing MOF structures for oxygen storage. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：In this work, we develop a model predictive control scheme for nonlinear systems using autoencoder-based reduced-order machine learning models. First, an autoencoder is developed for model order reduction by projecting the process states onto a low-dimensional space using data generated from open-loop simulations of the nonlinear system in the original high-dimensional space. Subsequently, reduced-order recurrent neural networks (RNN) are developed to capture the dominant dynamics of the nonlinear system using the low-dimensional data. Lyapunov-based model predictive control (MPC) scheme using RNN models in low-dimensional space is developed to stabilize the nonlinear system. Finally, a diffusion-reaction process example is used to demonstrate the effectiveness of the proposed reduced-order RNN modeling approach and RNN-based predictive control method. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Hassan, Yarima MudassirGuan, Beh HoeChuan, Lee KeanHamza, Mohammed Falalu...
10页
查看更多>>摘要：Oil reservoirs around the world are facing issues with the extraction ability of the accessible natural resources in the oil fields. Recent investigations on oil recovery have revealed that nanoparticles (NPs) possess a great potential on some parameters like rheology, interfacial tension (IFT), and rock wettability which help in uplifting the trapped oil. In this study, the influence of ZnO/SiO2 NPs concentration on oil recovery parameters (rheology, IFT, and wettability) has been investigated. The ZnO/SiO2 nanocomposite was synthesized and characterized using state-of-the-art techniques, afterwards, NPs were dissolved in brine followed by the formation of nanofluids at various concentrations. The results have indicated that the ZnO/SiO2 NPs at high concentration (0.1 wt. %) produced a considerable change in the rheology, IFT, and wettability. The viscosity (cP) of ZnO/SiO2 composite fluids has increased from 0.95 +/- 0.03 to 1.29 +/- 0.14, while the IFT (mN/m) was reduced from 12.93 +/- 1.55 to 1.02 +/- 0.05, and the contact angle (degrees) from 141 +/- 28 to 62 +/- 11. Overall, the changes in the rheology, IFT, and wettability were found to improve with an increase in ZnO/SiO2 NPs concentrations. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
Khooshechin, SajadMoosavian, Mohamman AliSafdari, JaberMallah, Mohammad Hassan...
11页
查看更多>>摘要：In this study, the mean drop diameter and drop size distribution have been investigated in a pilot plant of a new type of extraction column entitled L-shaped pulsed packed extraction column by using two liquid systems of toluene/acetone/water and n-butyl/acetone/water in the presence of mass transfer in two directions. The effects of operational variables, physical properties and mass transfer direction have been considered on the dispersed drop size. It is found that the mean drop diameter and drop size distribution is significantly affected by the pulsation intensity and interfacial tension of liquid system. However, the phases flow rates and mass transfer direction have a weaker impact. Furthermore, it is observed that the mean drops diameter in the horizontal and vertical sections of the used column have mostly the same size and it is considered as a significant advantage. Finally, new correlations are proposed to accurately predict the mean drop size and drop size distribution. Good agreement between predictions and experiments was found for all operating conditions, chemical systems and mass transfer direction that were investigated. (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
查看更多>>摘要：There is a drive for ultra-high recoveries in waste and brackish water RO desalination due to high brine disposal costs. In this work, two novel dynamic and cyclic designs (i.e. feed reversal and retentate recycle with a time-varying ratio in stage 3, as well as stage rotation between 1 and 3) are proposed to achieve a 90% recovery while alleviating scaling potential. The designs are conducted following FilmTec's guidelines and are simulated using validated models published previously. It is shown that retentate recycle suppresses concentration polarization, despite a higher pressure drop. Feed reversal leads to a quick drop of salt concentration due to mixing of fresh feed and brine. However, if the feed reversal is applied to the same stage, the salt concentration on the other end may be higher than brine concentration for a short period of time. Such a behavior is not observed during rotations between stages 1 and 3, whether the feed is reversed or not. Interestingly, the designs at 90% recovery demand only a few percent more energy than traditional two-stage designs operated at 80% recovery. Moreover, cycle-to-cycle salt build-up in batch-type ROs is absent in both dynamic designs presented in this work. (C) 2022 The Author(s). Published by Elsevier Ltd on behalf of Institution of Chemical Engineers.
查看更多>>摘要：Development of high proton-conducting membranes is the major demand in energy conversion, sensing, and catalysis. The emerging ionic covalent organic frameworks (iCOFs) with abundant and well-arranged proton-conducting groups offer new materials for efficient proton conduction. However, the poor processability of iCOFs makes it difficult to fabricate defect-free membranes. Herein, we use the interfacial reaction method to synthesize high crystalline iCOF nanosheets (NUS-9) which are then processed into defect-free membranes by vacuum-assisted assembly method. The plenty of intrinsic orderly aligned sulfonic acid groups in the iCOF skeletons endows the nanosheets with intrinsic high proton conductivity. Furthermore, the deoxyribonucleic acid molecules (DNA) with sequential linear arranged phosphate groups are intercalated into the iCOF membrane. The synergetic effect of orderly intrinsic and extrinsic proton-conducting sites gives the resulting DNA@iCOF membranes high proton conductivity of up to 494.7 mS cm(-1) (98% RH, 80 degrees C), which is among the highest values of the state-of-the-art COF-based proton conductors. Besides, it also retains high conductivity over a wide range of RH (40100%) and temperature (30-80 degrees C). (C) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
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