Simulation of Organic Liquid Products Deoxygenation by Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Process Modeling and Simulation

In this work, the deoxygenation of organic liquid products (OLP) obtained by thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO2) as solvent, with Aspen-HYSYS process simulator was systematically investigated. In a previous study, the thermodynamic data basis and EOS modeling necessary to simulate the deoxygenation of OLP has been presented [Molecules 2021, 26, 4382. https://doi.org/10.3390/molecules26144382]. This work address a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 pressure pump, and 02 make-up of CO2, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95 and 92.78% (wt.) in solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenates compounds with concentrations up to 32.66% (wt.) in solvent-free basis, showing that organic liquid products (OLP) was deacidified and SC-CO2 was able to deacidify OLP and to obtain fractions with lower olefins content. The best deacidifying conditions was obtained at 333 K, 140 bar, and (S/F) = 17.

Influence of sucrose reduction on fouling during the production of dulce de leche

In this Research Communication we focus the food industry´s broad tendency to decrease sugar content in food products onto dulce de leche (DL) and examine the influence of sucrose reduction on the detrimental deposits formed during the production process. The method used to identify the impact produced directly on the heat exchanger during the production of this product with low sucrose content required varying the quantity of sucrose in the milk. Different percentages of sucrose (20, 15, 10, 5 and 0% w/w) were submitted to the DL concentration process in a process simulator. After concentration, the quantification of the deposits formed in each was carried out and these deposits were characterized according to their composition. Methods such as Kjeldahl, Pregl-Dumas and sem-EDS were used. Thus, the work highlights the need to change the product manufacturing process due to changes in the formulation that directly impact the formation of deposits in the equipment used (fouling). This deposit changes significantly in relation to its quantity as well as in relation to the composition and chemical characteristics as the gradual reduction of the sucrose content in the production takes place. Therefore, these impacts must be considered in order to maintain better manufacturing and ensure efficient cleaning of equipment.

Corrosion behaviour of hot-dip Zn-Al-Mg coatings with different Al content

Purpose The purpose of the present study is to simulate the industrial hot-dip process of Zn-2.5Wt.%Mg-3 Wt.%Al and Zn-2.5 Wt.%Mg-9 Wt.%Al-0.15 Wt.%Si coatings and to study the effect of low and high Al variation on their microstructure, microhardness, adhesion and corrosion behaviour. Design/methodology/approach The hot-dip Zn-2.5 Mg-xAl coating simulation on steel substrate was carried out using a hot-dip process simulator. The microstructure of the coatings was characterized using a scanning electron microscope, energy dispersive spectroscopy and X-ray diffraction. The corrosion behaviour of the coatings was studied using a salt spray test in 5% NaCl solution as well as dynamic polarization in 3.5% NaCl solution. Findings Microhardness of the developed Zn-2.5 Mg-xAl coatings has been found to be approximately two times higher than that of the conventional galvanized coating. Zn-2.5 Mg-3Al coating has exhibited two times higher corrosion resistance as compared to that of Zn-2.5 Mg-9Al-0.15Si coating because of formation of more homogeneous and defect-free microstructure of the former. The MgZn2 phase has undergone preferential dissolution and provided Mg2+ ions to form a protective film. Originality/value The relative corrosion resistance of the two Zn–Al–Mg coatings with different Al content has been studied. The defect formed because of higher Al addition in the coating has been detected, and its effect on corrosion behaviour has been analysed.

Method for Efficient Regeneration of Solvent Mixture: Extractive Heterogeneous-Azeotropic Distillation

The fine chemical and pharmaceutical industries use large amounts of various organic solvents in their manufacturing processes. By reusing them, production costs can be significantly reduced. If we can regenerate waste solvent mixtures, we have the opportunity to reuse them in the production process or in other production processes. Our study illustrates an efficient regeneration process using the example of a four-component solvent mixture. Calculations were performed in a professional process simulator to demonstrate that the highly non-ideal Water-Ethyl Alcohol-Methyl Ethyl Ketone-Ethyl Acetate solvent mixture can be efficiently decomposed into azeotropic pairs and thus regenerated by the extractive heterogeneous-azeotropic distillation technique.

An adaptive real-time grey-box model for advanced control and operations in WRRFs

Grey-box models, which combine the explanatory power of first-principle models with the ability to detect subtle patterns from data, are gaining increasing attention in wastewater sectors. Intuitive, simple structured but fit-for-purpose grey-box models that capture time-varying dynamics by adaptively estimating parameters are desired for process optimization and control. As an example, this study presents the identification of such a grey-box model structure and its further use by an Extended Kalman Filter (EKF), for the estimation of the nitrification capacity and ammonia concentrations of a typical Modified Ludzack-Ettinger (MLE) process. The EKF was implemented and evaluated in real time by interfacing Python with SUMO (Dynamita™), a widely used commercial process simulator. The EKF was able to accurately estimate the ammonia concentrations in multiple tanks when given only the concentration in one of them. Besides, the nitrification capacity of the system could be tracked in real time by the EKF, which provides intuitive information for facility managers and operators to monitor and operate the system. Finally, the realization of EKF is critical to the development of future advance control, for instance, model predictive control.

Simultaneous simulation and optimization of multiple dividing wall columns

In this work we present a new approach that we use to simulate and optimize multiple dividing wall columns at the same time. Instead of considering all model equations as constraints and all process variables as optimization variables in a large and highly nonlinear optimization problem we only incorporate a subset of the model equations as constraints and a subset of the process variables as optimization variables. The remaining process variables are calculated from this subset by a robust and fast calculation procedure. This calculation procedure also ensures that the remaining model equations are satisfied. A comparison with the commercial process simulator Aspen Plus shows that with the new approach multiple dividing wall columns can be optimized more stable and better solutions are found. Moreover the time needed to find an optimal design decreases significantly.

SIMULATION-DRIVEN DEVELOPMENT FOR COARSE COMMINUTION PROCESS - A CASE STUDY OF GEITA GOLD MINE, TANZANIA USING PLANTSMITH PROCESS SIMULATOR

A comminution process is a material size reduction and separation process which is primarily used in the aggregates and the minerals processing industry. Knowledge related to equipment’s operation, raw material properties, operational strategies, control system, maintenance, etc. is needed to design a capable plant. New needs are arising from the industry for existing operational crushing plants such as investigation for improvements, upscaling, and downscaling of the capacity. The paper presents an application of simulation-driven development for a crushing plant in an existing gold processing plant. Due to the change in ore characteristics and the need for optimizing the cost of operation, it is required to investigate the opportunities for improvement and alternative options for downscaling the capacity of the plant. A systematic process for configuring, developing, and evaluating alternative concepts using a process simulation tool is presented. The results show the process of generating knowledge for alternative crushing plant operation settings and how the choices can be selected and eliminated using boundary conditions. The evaluation presents possible improvements and alternative concepts with their opportunities and pitfalls.