Challenges in Replacing Heuristics-Based Trialand-Error Procedures by Mathematical Optimization for Basic Equipment Design

Two subsequent separation processes are required to produce absolute ethanol (at least purity of 99.5% v/v),namely the distillation and adsorption processes. Thus, it is important to find the optimum operation conditionfor those following processes. The aims of the present study are to optimize the feed plate of distillation and thetemperature of feed adsorbent. This study is conducted using a continuous sieve tray distillation system with thenumber of 16 trays, the length-diameter ratio of 80.64, the reflux ratio of 3.5, and the feed with ethanol contentof 10 % v/v ethanol, which is produced via the fermentation process of molasses. To conduct the first aim of thisstudy, the feed enters the distillation column with several of variable feed plate, i.e. 12, 13, 14, and 15. This feedplate location is calculated from the top of the column. On the other hand, the second aim of this study, isconducted using the subsequent combination of distillation and adsorbent columns, where the distillate (purity ofethanol around 95% v/v) from the distillation column is then flowed into the adsorbent column with various feedadsorbent temperature, i.e. 80 °C, 90 °C, 100 °C, and 110 °C, to be purified as an absolute ethanol. Here theadsorbent column is designed as a fix bed adsorption column with a molecular sieve of 3A (zeolite) is used as anadsorbent for that purification process. Our results showed that the optimum feed plate is 14, because at thisplate the ethanol distillate has the highest content among those various variables. Meanwhile, the optimumtemperature of feed adsorbent is 90° C, which requires the least energy for the distillation - adsorption process,i.e. at 18691 kJ/kg absolute ethanol. This primary study is expected to be an alternative way to optimize theoperating condition of the sieve tray distillation-molecular sieve adsorption system by means of acquiring aminimum energy involving in the process to achieve the highest purity of ethanol.

Combining optimisation and simulation in an energy systems analysis of a Swedish iron foundry

The design of heat exchangers, especially shell and tube heat exchangers was originally proposed as a trial and error procedure where guesses of the heat transfer coefficient were made and then verified after the design was finished. This traditional approach is highly dependent of the experience of a skilled engineer and it usually results in oversizing. Later, optimization techniques were proposed for the automatic generation of the best design alternative. Among these methods, there are heuristic and stochastic approaches as well as mathematical programming. In all cases, the models are mixed integer non‐linear and non‐convex. In the case of mathematical programming solution procedures, all the solution approaches were likely to be trapped in a local optimum solution, unless global optimization is used. In addition, it is very well‐known that local solvers need good initial values or sometimes they do not even find a feasible solution. In this article, we propose to use a robust mixed integer global optimization procedure to obtain the optimal design. Our model is linear thanks to the use of standardized and discrete geometric values of the heat exchanger main mechanical components and a reformulation of integer nonlinear expressions without losing any rigor. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1907–1922, 2017

Design of a thermally integrated bioethanol-fueled solid oxide fuel cell system integrated with a distillation column

Optimisation of the integrated water – energy systems: a review with a focus in Process Systems Engineering

Chapter 10 Pinch point analysis

Novozymes to increase bioethanol capacity in China

A Library of GDP Problems Library of GDP problems ready to be solved More than 25 different GDP problems relevant to Process Systems Engineering and Superstructure Optimization Methanol production process Hydrodealkylation (HDA) process to produce Toluene Biofuel processing network Heat exchanger network evaluating modular process design Plant capacity expansion model Synthesis gas production plant from methane Kaibel distillation column Tray distillation column design Problem ranging from 6 to 31968 continuous variables, 2 to 516 disjunctions, 0 to 5040 integer variables, and 30 to 14927 constraints pip install gdplib

Design and commercial operation of a discretely heat-integrated distillation column

Optimal configuration of ternary distillation columns using heat integration with external heat exchangers

A comparative study of controlling the externally heat-integrated double distillation columns (EHIDDiC)

Due to a simpler calculation process and better precision, the rotating-angle softened-truss model is often used to predict behaviours of reinforced concrete shell or panel structures. In the current algorithm of the rotating-angle softened-truss model, the calculation process is from strains to stresses, which needs a trial and error procedure. A new algorithm of the rotating-angle softened-truss model is proposed in this paper. The Poisson effect is included in the new algorithm. Its calculation process is from stresses to strains. The trial and error procedure is avoided, which simplifies the calculation process significantly. The reliability of the new algorithm is verified by test data of six panels.

Computational design optimization has been widely considered a promising technique to help designers address complex design challenges regarding building performance. However, a barrier to applying it to real-world projects is the difficulty in incorporating functional requirements and constraints into the design optimization process. In response, this study presents an optimization-assisted design approach for early-stage architectural design. The approach combines the application of EvoMass, an integrated building mass design generation and optimization tool, and the soft constraint strategy. The combination allows designers to integrate various design requirements and constraints into the optimization, which makes it produce results with higher practical values. To demonstrate the efficacy of the approach, two case studies are presented, which show that the application of optimization facilitates designers to better formulate the design problem and rapidly investigate different design directions for exploration and information extraction.

A distillation column with the possibility of heat exchange on every tray (a fully diabatic column) is optimized in the sense of minimizing its total entropy production. This entropy production counts the interior losses due to heat and mass flow as well as the entropy generated in the heat exchangers. It is observed that the optimal heating distribution, i.e. the heat exchange required on each tray, is essentially the same for all trays in the stripping and rectification sections, respectively. This makes a column design with consecutive interior heat exchanger and only one exterior supply for each of the two sections very appealing. The result is only slightly dependent on the heat transfer law considered. In the limit of an infinite number of trays even this column with resistance to transfer of heat becomes reversible.

Fouling is a chronic problem in heat exchangers, and traditional analysis methods often require significant effort, making them time-consuming and impractical for industrial settings. This study uses aspen plus software to analyze fouling in a shell-and-tube heat exchanger that preheats feed for a distillation column. The objective of this study is to compare design, rating, and simulation modes to assess tube-side fouling, interactions between thermal and hydraulic analyses, and its impact on distillation column operations, including the cost increase due to fouling. Cases include a clean scenario, four with varying fouling resistances, and four with varying fouling layer thicknesses. The findings indicate that while design mode is informative, it is impractical for real-time analysis. Rating mode identifies potential malfunctions, but simulation mode proves superior by providing real-time data. Based on simulation results, the available heat duty decreases almost linearly with increasing fouling resistance, resulting in a maximum decrease of 31.25%. As the fouling resistance increased, the shell-side outlet temperature also rose from 69.17 °C to 75.75 °C, while the tube-side outlet temperature dropped from 60 °C to 49.35 °C. This prevented the heat exchanger from reaching the required inlet temperature for the distillation process, leading to an increase in reboiler duty. This study concludes that using the appropriate mode allows for addressing fouling with a simplified, reliable approach, even without historical plant data or the need to engage in complex mathematical methods.