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15 pages, 2033 KiB

Open AccessArticle

Optimization and Control of Propylene Production by Metathesis of 2-Butene

by Andrei Maxim Andrei and Costin Sorin Bildea

Processes 2023, 11(5), 1325; https://doi.org/10.3390/pr11051325 - 25 Apr 2023

Cited by 1 | Viewed by 2593

Abstract

This article considers the design and control of the 2-butene metathesis process. The process transforms a low-value feedstock derived from a fluid catalytic cracking unit into more valuable products. The economical optimization is applied to the preheat–reaction and separation sections, with the objective [...] Read more.

This article considers the design and control of the 2-butene metathesis process. The process transforms a low-value feedstock derived from a fluid catalytic cracking unit into more valuable products. The economical optimization is applied to the preheat–reaction and separation sections, with the objective of minimizing the total annual cost. The dynamic response and control of the plant are evaluated for feed flow perturbations. Although the process control system acts as a first line of defense against potential hazards, other independent safety layers are discussed with safety limits specific to the critical equipment of the 2-butene metathesis unit. The results prove that the metathesis reaction of 2-butene over a mesoporous tungsten catalyst is economically attractive. For a 5.7 t/h feed rate consisting of 2-butene (70% molar) and n-butane (30% molar), a reaction–separation plant (without recycle) requires 6570 × 10³ $ investment and has a profitability of 2300 × 10³ $/year. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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19 pages, 13749 KiB

Open AccessArticle

Effect of Packing Structure Evolution on the Flow Characteristics in a Binary Composite Packed Bed Based on DEM-CFD Method

by Cunliang Shen, Mingchun Li, Jie Ji, Xin Yang, Laishi Li and Yusheng Wu

Processes 2023, 11(3), 732; https://doi.org/10.3390/pr11030732 - 1 Mar 2023

Cited by 2 | Viewed by 1938

Abstract

The evolution of mesoscale structures of particle packing in binary composite packed beds and their effects on flow characteristics and wall effects were investigated using the discrete element method (DEM) and computational fluid dynamics (CFD). The DEM model was used to build a [...] Read more.

The evolution of mesoscale structures of particle packing in binary composite packed beds and their effects on flow characteristics and wall effects were investigated using the discrete element method (DEM) and computational fluid dynamics (CFD). The DEM model was used to build a series of randomly mixed packing structures of particles in accordance with the dynamic change of mass ratio between particles in two size ranges, which were then confirmed by the findings of an X-ray tomography (CT) scan. The results show that the packing structure of b25s75 was conducive to reducing the influence of wall effect in packed bed reactors. For b25s75, the dimensionless distance of radial porosity fluctuation from the wall is 0.3705, which is the smallest among the five packing models, indicating that this structure plays a suppressive role on the wall effect. In addition, the uniformity of velocity and temperature distributions in both the radial and axial directions of different packing structures were compared. The standard deviations of radial relative velocity distributions in the packed beds of b100, b75s25, b25s75 and s100 are 0.28, 0.178, 0.139 and 0.156, respectively, indicating that the stacking mode of b25s75 can make the fluid flow and the gas–solid interactions more uniform. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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17 pages, 7034 KiB

Open AccessArticle

Non-Conventional Reinforced EPS and Its Numerical Examination

by Katalin Voith, Bernadett Spisák, Máté Petrik, Zoltán Szamosi and Gábor L. Szepesi

Processes 2023, 11(1), 12; https://doi.org/10.3390/pr11010012 - 21 Dec 2022

Cited by 4 | Viewed by 1644

Abstract

In the last decades, the EPS (expanded polystyrene) and the XPS (extruded polystyrene) have become the most frequently used thermal insulation. Furthermore, the XPS has step resistant thermal insulation with higher strength. Nowadays in our current economic situation, the circular economy plays a [...] Read more.

In the last decades, the EPS (expanded polystyrene) and the XPS (extruded polystyrene) have become the most frequently used thermal insulation. Furthermore, the XPS has step resistant thermal insulation with higher strength. Nowadays in our current economic situation, the circular economy plays a significant role. That means we need to intend making a product that becomes waste as late as possible. Instead of a product, the goal is to return it to the economy as a basic material for a new product. Instead of generating waste, a new chance must be given by reusing it. Based on that consideration, our research work was in producing reinforced EPS material, which has the physical and thermal properties at least, as the XPS is much more expensive to produce. For reinforcement, materials have been chosen, in terms of its current life cycle, considered as product or waste. The first choice were plastic straws and cutleries that will be redrawn from the market. The next additives were renewable materials from agriculture like straws of wheat. It is essential for this research work to map the possible raw materials, i.e., EPS and XPS. The article collects the properties of the EPS and XPS and the related simulation methods that can be found in the literature. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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7 pages, 1449 KiB

Open AccessCommunication

Concept of an Enzymatic Reactive Extraction Centrifuge

by Francesca Meyer, Nijat Gasimov, Paul Bubenheim and Thomas Waluga

Processes 2022, 10(10), 2137; https://doi.org/10.3390/pr10102137 - 20 Oct 2022

Cited by 1 | Viewed by 1762

Abstract

Biocatalytic processes often provide an ecological alternative to many chemical processes. However, further improvements in terms of the economic efficiency are required. In order to achieve that, the concept of process integration is a promising option. Applying this within a biocatalytic process, a [...] Read more.

Biocatalytic processes often provide an ecological alternative to many chemical processes. However, further improvements in terms of the economic efficiency are required. In order to achieve that, the concept of process integration is a promising option. Applying this within a biocatalytic process, a highly integrated apparatus working as a reactive extraction centrifuge was developed and operated. For this purpose, a commercially available extraction centrifuge was modified to implement a biocatalytic reaction. The novel apparatus was used within a multi-enzyme cascade for the production of a natural flavor and fragrance, namely cinnamic ester. The characterization of the reactive extraction centrifuge and the suitable operation conditions for the inlet streams and the rotational speed for a stable operation were determined. Furthermore, different initial substrate concentrations were applied to prove the reaction. The results provide a successful proof of concept for the novel reactive extraction centrifuge. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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17 pages, 2498 KiB

Open AccessArticle

Optimization of Sour Water Stripping Unit Using Artificial Neural Network–Particle Swarm Optimization Algorithm

by Ye Zhang, Zheng Fan, Genhui Jing and Mohammed Maged Ahemd Saif

Processes 2022, 10(8), 1431; https://doi.org/10.3390/pr10081431 - 22 Jul 2022

Cited by 2 | Viewed by 2418

Abstract

Sour water stripping can treat the sour water produced by crude oil processing, which has the effect of environmental protection, energy saving and emission reduction. This paper aims to reduce energy consumption of the unit by strengthening process parameter optimization. Firstly, the basic [...] Read more.

Sour water stripping can treat the sour water produced by crude oil processing, which has the effect of environmental protection, energy saving and emission reduction. This paper aims to reduce energy consumption of the unit by strengthening process parameter optimization. Firstly, the basic model is established by utilizing Aspen Plus, and the optimal model is determined by comparative analysis of back propagation neural network (BPNN), radial basis function neural network (RBFNN) and generalized regression neural network (GRNN) models. Then, the sensitivity analysis of Sobol is used to select the operating variables that have a significant influence on the energy consumption of the sour water stripping system. Finally, the particle swarm optimization (PSO) algorithm is used to optimize the operating conditions of the sour water stripping unit. The results show that the RBFNN model is more accurate than other models. Its network structure is 5-66-1, and the expected value has an approximately linear relationship with the output value. Through sensitivity analysis, it is found that each operating parameter has an impact on the sour water stripping process, which needs to be optimized by the PSO algorithm. After 210 iterations of the PSO algorithm, the optimal system energy consumption is obtained. In addition, the cold/hot feed ratio, sideline production position, tower bottom pressure, hot feed temperature, and cold feed temperature are 0.117, 18, 436 kPa, 146 °C, and 35 °C, respectively; the system energy consumption is 5.918 MW. Compared with value of 7.128 MW before optimization, the energy consumption of the system is greatly reduced by 16.97%, which shows that the energy-saving effect is very significant. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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13 pages, 4514 KiB

Open AccessEditor’s ChoiceArticle

An Investigation on the Features of Deformation and Residual Stress Generated by Patch Welding with Different Plate Sizes

by Takehito Hashiguchi, Mikihito Hirohata and Károly Jármai

Processes 2022, 10(7), 1312; https://doi.org/10.3390/pr10071312 - 4 Jul 2022

Cited by 2 | Viewed by 1823

Abstract

Welding is widely used to manufacture and repair steel structures such as piping and pressure vessels. Welding induces deformation and residual stress, which influences the mechanical performance of the structural members. Noting patch welding, which is applied to repair steel structures, a series [...] Read more.

Welding is widely used to manufacture and repair steel structures such as piping and pressure vessels. Welding induces deformation and residual stress, which influences the mechanical performance of the structural members. Noting patch welding, which is applied to repair steel structures, a series of patch welding experiments and numerical analyses were carried out. The features of out-of-plane deformation and residual stress by patch welding were examined by changing the patch size. The out-of-plane deformation showed different modes in the patch joints. The magnitude of the out-of-plane deformation depended on the patch size. The tensile residual stress at the weld toe increased with the enlargement of the patch size. The costs for the different sizes of patch welding were estimated for choosing the patch size reasonably. The patch size should be determined by considering the mechanical influences of welding and the economic viewpoints of the welding process. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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17 pages, 4825 KiB

Open AccessArticle

Investigation on the Separation Performance and Multiparameter Optimization of Decanter Centrifuges

by Xiang Kang, Liuxi Cai, Yun Li, Xiufeng Gao and Guangqian Bai

Processes 2022, 10(7), 1284; https://doi.org/10.3390/pr10071284 - 29 Jun 2022

Cited by 5 | Viewed by 5603

Abstract

Decanter centrifuges are widely used for solid–liquid separation. Although parameter analysis for decanter centrifuges was performed by numerical simulation in previous studies, some structural parameters are rarely mentioned and investigated. At the same time, the results obtained by the single-parameter analysis in previous [...] Read more.

Decanter centrifuges are widely used for solid–liquid separation. Although parameter analysis for decanter centrifuges was performed by numerical simulation in previous studies, some structural parameters are rarely mentioned and investigated. At the same time, the results obtained by the single-parameter analysis in previous studies are difficult to truly realize the comprehensive performance optimization of decanter centrifuges. In this paper, the influences of the window structure and bowl–conveyor gap on the separation performance are systematically analyzed with the employment of a numerical computation method. The results show that the increase in the window angle and window height will accelerate the flow of the upper layer, while the increase in the bowl–conveyor gap may make particles flow through it directly and further form a solid retention zone. Both of the structural changes will lead to deterioration of the separation performance. On the basis of numerical simulation analysis, a genetic algorithm-based method for multiparameter optimization is proposed in this paper. Parameter optimization shows that bowl speed and feed flow rate have the most significant effects on the separation performance and power consumption. Compared with the minimal specific power in the first generation, the optimized specific power is reduced by 15.7%, and the cake solid content merely decreases by 0.044%. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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11 pages, 3366 KiB

Open AccessArticle

Sorbent Properties of Orange Peel-Based Biochar for Different Pollutants in Water

by Weichao Zhang, Yuwei Wang, Liquan Fan, Xingmei Liu, Weiyan Cao, Honglin Ai, Ziteng Wang, Xijun Liu and Hongge Jia

Processes 2022, 10(5), 856; https://doi.org/10.3390/pr10050856 - 26 Apr 2022

Cited by 16 | Viewed by 3238

Abstract

Efficient and reasonable utilization of waste biomass resources can not only avoid serious waste of material resources, but also solve the problem of environmental pollution. Therefore, the development of efficient and environmentally friendly waste biomass carbonization technology has important practical significance. Here, the [...] Read more.

Efficient and reasonable utilization of waste biomass resources can not only avoid serious waste of material resources, but also solve the problem of environmental pollution. Therefore, the development of efficient and environmentally friendly waste biomass carbonization technology has important practical significance. Here, the activated carbon from orange peel (OAC) is prepared by potassium hydroxide (KOH) activation combined with high-temperature carbonization. The adsorption effects of OAC on three different pollutant aqueous solutions, methylene blue (MB), tetracycline (TC), and fluorescein sodium (NaFL), are examined. The OAC absorbent has excellent adsorption capacity for MB, TC, and NaFL pollutants of 10 mg L⁻¹, with adsorption rates of 99.17%, 73.5%, and 94.24%, respectively. This study provides a new idea for turning waste biomass into treasure and eliminating the hidden danger of environmental pollution. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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Review

Jump to: Research

22 pages, 1933 KiB

Open AccessReview

Utilization of Cold Energy from LNG Regasification Process: A Review of Current Trends

by Muhammad Haziq Noor Akashah, Nor Erniza Mohammad Rozali, Shuhaimi Mahadzir and Peng Yen Liew

Processes 2023, 11(2), 517; https://doi.org/10.3390/pr11020517 - 8 Feb 2023

Cited by 22 | Viewed by 12052

Abstract

Liquified natural gas (LNG) is a clean primary energy source that is growing in popularity due to the distance between natural gas (NG)-producing countries and importing countries. The large amount of cold energy stored in LNG presents an opportunity for sustainable technologies to [...] Read more.

Liquified natural gas (LNG) is a clean primary energy source that is growing in popularity due to the distance between natural gas (NG)-producing countries and importing countries. The large amount of cold energy stored in LNG presents an opportunity for sustainable technologies to recover and utilize this energy. This can enhance the energy efficiency of LNG regasification terminals and the economic viability of the LNG supply chain. The energy stored in LNG in the form of low temperatures is referred to as cold energy. When LNG is regasified, or converted back into its gaseous form, this cold energy is released. This process involves heating the LNG, which causes it to vaporize and release its stored energy. The current state-of-the-art techniques for LNG cold energy utilization, including power generation, air separation, traditional desalination, and cryogenics carbon dioxide (CO₂) capture are discussed in this review. While most of the current LNG cold energy utilization systems are presented, potential future applications are also discussed. The commercialization of sustainable technologies, such as improvement strategies for LNG cold energy utilization, is becoming increasingly important in the energy industry. Full article

(This article belongs to the Special Issue Chemical Engineering and Technology)

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