Rigorous Simulation-Based Automatic Identification of the Optimal Separation Sequence

Conceptual process design and process optimization of triple-column pressure-swing distillation for the separation of ternary mixtures embedding two azeotropes with different feed composition via thermodynamic insights and genetic algorithm

Simulation of air quality and cost to ventilate swine farrowing facilities in winter

Lean holistic fuzzy methodology employing cross-functional worker teams for new product development projects: A real case study from high-tech industry

In this study, the task is to develop a heuristic procedure for the synthesis of systems for the separation of multicomponent mixtures, which would take into account the uncertainty of the factors of the separation processes and the multivariance of the solution.
 The authors reviewed the current state of the existing methods for the separation of mixtures. Many works devoted to the synthesis of effective systems for the separation of multicomponent mixtures leave unsolved the problem of taking into account the uncertainty of many factors of the separation processes. In the presented work, it is proposed that a heuristic approach is applied using fuzzy logic.
 The proposed procedure is based on the choice of a separation sequence that takes into account the value of the separation coefficient and the difference in boiling points of two adjacent key components. The proposed strategy is based on an estimate of the likelihood of each rule for each possible separation. The search for solutions has five stages. First, the mixture to be separated and the available equipment are determined. After that, an ordered list of all separation options is drawn up with possible values of the economic costs of their implementation. Next, the mass load of possible separation is estimated and the separation with the minimum value of the separation ratio is selected. The heuristic is that the heavy separation is done last. And, at the last step, the most economical separation scheme is selected.
 The above strategy at the stage of quantitative assessment is subject to the value of the threshold S (boiling point difference). This point can be used to determine the quasi-optimal solutions to the problem of sequencing according to the rules of relaxation of separation. 
 For this fuzzy heuristic method for determining cost-effective separation sequences for mixtures, appropriate software has been developed. In addition, since the procedure uses the theory of fuzzy sets, the Fuzzy Logic Toolbox package of the Matlab was also used to solve the problem of synthesizing schemes for separating hydrocarbon mixtures. The proposed procedure was successfully tested in both software implementations using the example of separating a five-component mixture. 
 The main difference between the proposed approach and other approaches based on fuzzy logic for the synthesis of separation systems is the gradation of working rules and possible quantification of a set of rules, which eliminates conflicts between the rules.

The aim of this study was to evaluate the energy usage and total operation cost of the tractor grabber. The data was collected at FELCRA BERHAD Kawasan Titi Gantong, Bota, Perak. The total cost included all the operation in loading system and evacuation process of fresh fruit bunch (FFB). This study evaluated the energy usage of tractor grabber for three consecutive months using a newly purchased Mini Tractor Grabber Kubota L4400. This study was conducted based on the energy input-output methodology. Mathematical equations are used to determine the field capacity and examine energy usage. The result found that 153.38 MJha⁻¹ of input energy was required to produce 328.43 metric ton per month of FFB in June. The energy was dominated by fuel consumption, machinery and followed by labour. The total operating cost is based on the field capacity of the machine. This study was conducted and obtained the result, assumed that the total cost for a year is RM 47,444.24 and the cost per metric ton is RM 9.76 with energy consumption of 174.23 MJ. Conclusively, it means that the energy usage and cost of operation is efficiently and effectively used in oil palm productivity in FELCRA BERHAD Kawasan Titi Gantong.

Multicriteria design of separation sequences by including HSE criteria and uncertainty

Optimal design and sensitivity analysis of post-combustion CO2 capture process by chemical absorption with amines

The distillation-based separation of ideal liquid mixtures has been comprehensively studied. The optimization of the different separation structures has allowed the development of general heuristic rules to aid the designers in finding good solutions quickly for the type of problem at hand. The separation of nonideal mixtures is also an exhaustively studied area, but because of the complexity of the vapor−liquid−liquid behavior of such mixtures, it is more difficult to suggest guidelines for synthesis in separation sequences. On the other hand, recently several special so-called hybrid separation tools have also been involved in that kind of synthesis task, complicating further the synthesis problem. To obtain some general conclusions for the separation structure synthesis of such mixtures, in this study the separation of two nonideal quaternary mixtures containing one nonazeotropic-forming component (most volatile or least volatile) is studied based on optimization of the separation structures. The separation schemes involve the so-called extractive heterogeneous azeotropic distillation, which is a novel hybrid separation process. The economic optimization of the different separation structures results in the conclusion that the heuristic rule for ideal mixtures, that is, “easy separation first should be done and the complicated one should be made last”, is valid also for such nonideal mixtures.

Operation and maintenance costs have been compiled for 20 wastewater treatment plants in the range of 7 000 to 650 000 population equivalents. Great effort has been made to exclude the effects of local conditions on the costs. Data on energy and chemical consumption and manpower are given as well as the total operating costs and the distribution of manpower, energy, chemical and other costs. The results show that costs for manpower and electricity as well as total costs on a per capita basis decrease with increasing plant size. The variation between individual plants is, however, large even when differences in local conditions are accounted for.

The geometrical dimensions of a counterflow natural draft wet-cooling tower are optimized to obtain the minimum combined operational and capital cost compounded over the economic life of the cooling tower. Wet-cooling tower performance evaluation software is employed in conjunction with an optimization algorithm to obtain the optimum cooling tower geometry. It is shown that the inlet height of the cooling tower, which primarily determines the operational cost, is the most critical parameter influencing the total operational and capital cost of a cooling tower. The effects of the diameter of the cooling tower and the volume of the concrete have a less pronounced effect on the total operational and capital cost of a cooling tower. The results of the mathematical optimization algorithm are verified by a manual investigation of the solution domain.

Petrochemical tail gases have various components and many separation methods, thus there are many possible design schemes, making it difficult to determine the optimal scheme. In this work, a graphic synthesis method was used to design a hybrid multi-input refinery gas separation process consisting of membranes, pressure swing adsorption (PSA), shallow condensation (SC), and distillation units for the production of valuable products which include H2, C2, LPG, and C5+. Ten refinery gases with different compositions were visualized and represented with vector couples in a triangular coordinate system. Firstly, according to the characteristics of the refinery gases, the feeds located in the same region of the triangular coordinate system were merged to simplify the number of input streams, then ten original input streams were combined into two mixed streams. Secondly, the optimal separation sequence was determined by using the unit selection rules of a graphic synthesis method. Thirdly, the process was simulated in UniSim Design and the process parameters were determined by sensitivity analysis. Finally, economic assessments were carried out, which led to an annual gross product profit of USD 38.62 × 106 and a payback period of less than 4 months.

A tri-layer stochastic framework to manage electricity market within a smart community in the presence of energy storage systems

Hybrid membrane-distillation systems are reported to be an energy-efficient separation processes compared to conventional distillation process; especially for separating close-boiling mixtures. However, several optimization methods are available and can be applied to find a cost-effective design and operation of hybrid membrane-distillation systems. This work evaluates the hybrid system design in terms of energy and compares the performance (i.e. the accuracy and computational efficiency) of stochastic optimisation method (Simulated Annealing) and deterministic method (Pattern search method) for optimisation of process operating conditions. The parallel hybrid membrane-distillation system for the separation of ethylene-ethane mixture is selected for analysis. The decision variables manipulated for the optimisation are the stage cut and permeate pressure. Results show that pattern search is faster than Simulated Annealing but that is more able to find the close-global results. The difference between the optimal result found by Simulated Annealing and pattern search is about 0.02 % for the total operating costs, 0.3 % for the stage cut and 5 % for the permeate pressure. These findings suggest that it is possible to use deterministic method for optimisation complex system. However, to locate an optimal solution and increase confidence in the result, a variety of initial points should be tested.

Proton exchange membrane fuel cell (PEMFC) electric vehicle is an effective solution for improving fuel efficiency and onboard emissions, taking advantage of the high energy density and short refuelling time. However, the higher cost and short life of the PEMFC system and battery in an electric vehicle prohibit the fuel cell electric vehicle (FCEV) from becoming the mainstream transportation solution. The fuel efficiency-oriented energy management strategy (EMS) cannot guarantee the improvement of total operating costs. This paper proposes an EMS to minimize the overall operation costs of FCEVs, including the cost of hydrogen fuel, as well as the cost associated with the degradations of the PEMFC system and battery energy storage system (ESS). Based on the PEMFC and battery performance degradation models, their remaining useful life (RUL) models are introduced. The control parameters of the EMS are then optimized using a meta-model based global optimization algorithm. This study presents a new optimal control method for a large mining truck operating on a real closed-road operation cycle, using the combined energy efficiency and performance degradation cost measures of the PEMFC system and lithium-ion battery ESS. Simulation results showed that the proposed EMS could improve the total operating costs and the life of the FCEV.

Battery health-aware and naturalistic data-driven energy management for hybrid electric bus based on TD3 deep reinforcement learning algorithm