ChemEngineering

21 pages, 2667 KiB

Open AccessArticle

CFD-Simulation of Isobutane Dehydrogenation for a Fluidized Bed Reactor

by Sergei A. Solovev, Olga V. Soloveva, Giyjaz E. Bekmukhamedov, Svetlana R. Egorova and Alexander A. Lamberov

ChemEngineering 2022, 6(6), 98; https://doi.org/10.3390/chemengineering6060098 - 19 Dec 2022

Viewed by 1903

Abstract

In the present study, a mathematical model of the isobutane dehydrogenation process for a laboratory reactor with a diameter of 2.8 cm and a height of 70 cm was created using CFD methods. A two-fluid model was selected as a model for the [...] Read more.

In the present study, a mathematical model of the isobutane dehydrogenation process for a laboratory reactor with a diameter of 2.8 cm and a height of 70 cm was created using CFD methods. A two-fluid model was selected as a model for the fluidization simulation, when the gas and solid granular phases were considered as continuous. The model of chemical kinetics considers three reactions that make the main contribution to the products mass fraction at the reactor outlet: the reaction of catalytic dehydrogenation of isobutane to isobutylene, the reaction of thermal cracking of isobutylene with the formation of methane and propylene, and the reaction of catalytic hydrogenation of propylene. The model was verified in a series of experimental studies. Experimental studies and numerical simulations were carried out for the process parameters: gas velocity 0.008, 0.012 and 0.016 m/s, gas temperature 550, 575, 600 and 625 °C, and catalyst mass 75, 100 and 125 g. The optimal process temperature was 575 °C, where the yield of isobutylene averaged 47.6% of the mass. As the temperature decreased, the yield of isobutylene decreased to 40.1% by weight on average. With an increase in temperature, the yield of isobutylene increased to 52.8% by weight on average, and the total yield of products of side reactions increased to 20% by weight on average. Changes in the gas velocity and catalyst mass had an insignificant effect on the values of the yield of isobutylene, but significantly affected the values of the yield of the by-products. Full article

(This article belongs to the Special Issue Feature Papers in Chemical Engineering)

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15 pages, 3917 KiB

Open AccessArticle

Sustainable Removal of Ammonia from the Anaerobic Digester Supernatant Line Using a Prussian Blue Analogue (PBA) Composite Adsorbent

by Paz Nativ, Zenebu Abera Derbew, Chen Dagan-Jaldety, Yaron Aviezer, Raz Ben-Asher and Ori Lahav

ChemEngineering 2022, 6(6), 97; https://doi.org/10.3390/chemengineering6060097 - 15 Dec 2022

Cited by 2 | Viewed by 3467

Abstract

This paper reports on the physico-chemical removal of NH₄⁺ from the supernatant line in municipal wastewater treatment plants (WWTPs), using zinc-hexa-cyano-ferrate (ZnHCF) beads. The work is divided into three parts: First, the characteristics of three (Zn-, Co-, Ni-) types of HCF [...] Read more.

This paper reports on the physico-chemical removal of NH₄⁺ from the supernatant line in municipal wastewater treatment plants (WWTPs), using zinc-hexa-cyano-ferrate (ZnHCF) beads. The work is divided into three parts: First, the characteristics of three (Zn-, Co-, Ni-) types of HCF beads were determined, with a finding that ZnHCF was the most suitable for the purpose of this work. Second, synthetic and actual supernatant wastewater was passed through a ZnHCF column for many cycles until apparent steady-state results were attained. Due to the very high affinity of the beads toward NH₄⁺ and the much lower affinity toward competing cations, the same regeneration solution could be used for many cycles (20 cycles in this work) without affecting the following adsorption breakthrough curve efficiency and the operational capacity, which was >88% at the end of all adsorption steps. Finally, a cost analysis was performed, revealing that the cost of removing ~500 mg/L of ammonia from the supernatant line is ~$0.02 per m³ of raw wastewater flowing into the plant if the ammonia is recaptured and sold as NH₄Cl. This may be cost-effective when the WWTP receives a higher-than-planned load, and an incentive exists for alleviating the ammonia load on the oxidation reactor. Full article

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15 pages, 3399 KiB

Open AccessArticle

Two-Step Conversion of CO₂ to Light Olefins: Laboratory-Scale Demonstration and Scale-Up Considerations

by Matti Reinikainen, Aki Braunschweiler, Sampsa Korpilo, Pekka Simell and Ville Alopaeus

ChemEngineering 2022, 6(6), 96; https://doi.org/10.3390/chemengineering6060096 - 06 Dec 2022

Cited by 1 | Viewed by 2308

Abstract

The highly selective production of light olefins from CO₂ was demonstrated for the first time with a laboratory-scale process comprising consecutive reverse water gas shift (RWGS) and Fischer–Tropsch (FT) reactors. The RWGS reaction, catalyzed by rhodium washcoated catalyst at 850 °C yielded [...] Read more.

The highly selective production of light olefins from CO₂ was demonstrated for the first time with a laboratory-scale process comprising consecutive reverse water gas shift (RWGS) and Fischer–Tropsch (FT) reactors. The RWGS reaction, catalyzed by rhodium washcoated catalyst at 850 °C yielded good quality syngas with conversion values close to the thermodynamic equilibrium and without experiencing catalyst deactivation from carbon formation or sintering. For the FT synthesis, a packed bed Fe-Na-S/α-Al₂O₃ catalyst was used. The highest light olefin selectivity observed for the FT-synthesis was 52% at 310 °C, GHSV of 2250 h⁻¹ and H₂/CO ratio of 1. However, the optimal conditions for the light olefin production were determined to be at 340 °C, a GHSV of 3400 h⁻¹ and a H₂/CO ratio of 2, as the CO conversion was markedly higher, while the light olefin selectivity remained at a suitably high level. In addition to the experimental results, considerations for the further optimization and development of the system are presented. The combined RWGS–FT process seems to work reasonably well, and initial data for basic process design and modeling were produced. Full article

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14 pages, 3658 KiB

Open AccessArticle

Development of Rigid Polyurethane Foams Based on Kraft Lignin Polyol Obtained by Oxyalkylation Using Propylene Carbonate

by Fernanda R. Vieira, Nuno V. Gama, Ana Barros-Timmons, Dmitry V. Evtuguin and Paula C. O. R. Pinto

ChemEngineering 2022, 6(6), 95; https://doi.org/10.3390/chemengineering6060095 - 06 Dec 2022

Cited by 1 | Viewed by 1604

Abstract

This study aimed to develop new rigid polyurethane foams (RPUFs) for thermal insulation based on kraft lignin, the main by-product of the pulp and paper industry. Crude lignin-based polyol (LBP) was obtained via the oxyalkylation of kraft lignin using propylene carbonate (PC). A [...] Read more.

This study aimed to develop new rigid polyurethane foams (RPUFs) for thermal insulation based on kraft lignin, the main by-product of the pulp and paper industry. Crude lignin-based polyol (LBP) was obtained via the oxyalkylation of kraft lignin using propylene carbonate (PC). A design of experiments (DoE) was used to evaluate the effect of the isocyanate (NCO)-to-hydroxyl (OH)-group’s ratio, the content of crude LBP, the blowing agent (BA), and catalyst on the thermal conductivity and density of RPUFs. Statistical analysis revealed that the increase in crude LBP and BA content in the formulation decreases the thermal conductivity and density of the foams. In addition, the fact that LBP is a viscous polyol containing PC-oligomers appears to affect the cellular structure of RPUFs, and consequently reduces their mechanical and thermal properties. The main novelty of this study consisted in the careful optimization of the formulation, namely, with regard to the type of blowing agent and with the high content of crude LBP obtained from the oxyalkylation of LignoBoost kraft lignin without purification to obtain good quality RPUF that meets market requirements for insulation materials. Full article

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18 pages, 8606 KiB

Open AccessReview

Medicinal Chemistry of Quinazolines as Analgesic and Anti-Inflammatory Agents

by Mohamed F. Zayed

ChemEngineering 2022, 6(6), 94; https://doi.org/10.3390/chemengineering6060094 - 02 Dec 2022

Cited by 12 | Viewed by 2574

Abstract

Quinazoline is an essential scaffold, known to be linked with various biological activities. Some of the prominent biological activities of this system are analgesic, anti-inflammatory, anti-hypertensive, anti-bacterial, anti-diabetic, anti-malarial, sedative–hypnotic, anti-histaminic, anti-cancer, anti-convulsant, anti-tubercular, and anti-viral activities. This diversity in the pharmacological response [...] Read more.

Quinazoline is an essential scaffold, known to be linked with various biological activities. Some of the prominent biological activities of this system are analgesic, anti-inflammatory, anti-hypertensive, anti-bacterial, anti-diabetic, anti-malarial, sedative–hypnotic, anti-histaminic, anti-cancer, anti-convulsant, anti-tubercular, and anti-viral activities. This diversity in the pharmacological response of the quinazoline system has encouraged medicinal chemists to study and discover this system and its multitude of potential against several biological activities. Many of these studies have successfully investigated the structure–activity relationship to explore the specific structural features of their biological targets. The developing understanding of quinazoline derivatives and their biological targets presents opportunities for the discovery of novel therapeutics. This review represents different aspects of medicinal chemistry, including drug design, structure–activity relationship, and the mode of action of some analgesic and anti-inflammatory quinazoline compounds. It pays comprehensive attention to the analgesic and anti-inflammatory activities of quinazolines from the viewpoint of drug discovery and its development. Full article

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11 pages, 2375 KiB

Open AccessArticle

Mathematical Modeling and Experiments on Pyrolysis of Walnut Shells Using a Fixed-Bed Reactor

by Aysan Safavi, Christiaan Richter and Runar Unnthorsson

ChemEngineering 2022, 6(6), 93; https://doi.org/10.3390/chemengineering6060093 - 01 Dec 2022

Cited by 6 | Viewed by 2563

Abstract

Pyrolysis is a low-emission and sustainable thermochemical technique used in the production of biofuels, which can be used as an alternative to fossil fuels. Understanding the kinetic characterization of biomass pyrolysis is essential for process upscaling and optimization. There is no accepted model [...] Read more.

Pyrolysis is a low-emission and sustainable thermochemical technique used in the production of biofuels, which can be used as an alternative to fossil fuels. Understanding the kinetic characterization of biomass pyrolysis is essential for process upscaling and optimization. There is no accepted model that can predict pyrolysis kinetics over a wide range of pyrolysis conditions and biomass types. This study investigates whether or not the classical lumped kinetic model with a three-competitive reaction scheme can accurately predict the walnut shell pyrolysis product yields. The experimental data were obtained from walnut shell pyrolysis experiments at different temperatures (300–600 °C) using a fixed-bed reactor. The chosen reaction scheme was in good agreement with our experimental data for low temperatures, where the primary degradation of biomass occurred (300 and 400 °C). However, at higher temperatures, there was less agreement with the model, indicating that some other reactions may occur at such temperatures. Hence, further studies are needed to investigate the use of detailed reaction schemes to accurately predict the char, tar, and gas yields for all types of biomass pyrolysis. Full article

(This article belongs to the Special Issue Thermal Treatment of Biomass and Solid Municipal Waste)

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10 pages, 3321 KiB

Open AccessArticle

Prediction of Particle Size Distribution of Mill Products Using Artificial Neural Networks

by Akira Otsuki and Hyongdoo Jang

ChemEngineering 2022, 6(6), 92; https://doi.org/10.3390/chemengineering6060092 - 25 Nov 2022

Cited by 1 | Viewed by 1546

Abstract

High energy consumption in size reduction operations is one of the most significant issues concerning the sustainability of raw material beneficiation. Thus, process optimization should be done to reduce energy consumption. This study aimed to investigate the applicability of artificial neural networks (ANNs) [...] Read more.

High energy consumption in size reduction operations is one of the most significant issues concerning the sustainability of raw material beneficiation. Thus, process optimization should be done to reduce energy consumption. This study aimed to investigate the applicability of artificial neural networks (ANNs) to predict the particle size distributions (PSDs) of mill products. PSD is one of the key sources of information after milling since it significantly affects the subsequent beneficiation processes. Thus, precise PSD prediction can contribute to process optimization and energy consumption reduction by avoiding over-grinding. In this study, coal particles (−2 mm) were ground with a rod mill under different conditions, and their PSDs were measured. The variables studied included volume% (vol.%) of feed (coal particle), vol.% rod load, and grinding time. Our supervised ANN models were developed to predict PSDs and trained by experimental data sets. The trained models were verified with the other experimental data sets. The results showed that the PSDs predicted by ANN fitted very well with the experimental data after the training. Root mean squared error (RMSE) was calculated for each milling condition, with results between 0.165 and 0.965. Also, the developed ANN models can predict the PSDs of ground products under different milling conditions (i.e., vol.% feed, vol.% rod load, and grinding time). The results confirmed the applicability of ANNs to predict PSD and, thus the potential contribution to reducing energy consumption by optimizing the grinding conditions. Full article

(This article belongs to the Special Issue Exclusive Collection: Papers from the Editorial Board Members (EBMs) of ChemEngineering)

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14 pages, 1688 KiB

Open AccessArticle

Development of an Environmentally Friendly Technology for the Treatment of Aqueous Solutions with High-Purity Plasma for the Cultivation of Cotton, Wheat and Strawberries

by Mukhsindjan Kh. Ashurov, Erkindjan M. Ashurov, Maxim E. Astashev, Ilya V. Baimler, Sergey V. Gudkov, Evgeny M. Konchekov, Vasily N. Lednev, Natalya A. Lukina, Tatyana A. Matveeva, Anatoly G. Markendudis, Andrey V. Onegov, Dilbar K. Rashidova, Ruslan M. Sarimov, Konstantin F. Sergeichev, Shukhrat T. Sharipov, Alexander V. Simakin, Igor G. Smirnov, Sergey Y. Smolentsev, Muzzafar M. Yakubov, Denis V. Yanykin and Ivan A. Shcherbakov Show full author list Hide full author list

ChemEngineering 2022, 6(6), 91; https://doi.org/10.3390/chemengineering6060091 - 23 Nov 2022

Cited by 9 | Viewed by 1815

Abstract

The microwave setup for obtaining plasma-activated water (PAW) has been created. PAW contains significant concentrations of H₂O₂ and NO₃⁻, has a reduced content of O₂, high conductivity, a high redox potential and low pH. Likewise, [...] Read more.

The microwave setup for obtaining plasma-activated water (PAW) has been created. PAW contains significant concentrations of H₂O₂ and NO₃⁻, has a reduced content of O₂, high conductivity, a high redox potential and low pH. Likewise, the specific electrical conductivity and concentration of H₂O₂ and NO₃⁻ linearly depend on the treatment time. These parameters are simple and convenient markers for controlling the preparation of PAW. It has been established that PAW solutions with a concentration of 0.5–1.0% increase the germination energy, protect against fusarium and hyperthermia in cotton, wheat and strawberry seeds. In addition, PAWs have a positive effect on the growth rate of plants in the early stages of development. The use of PAW provides significant benefits over the chemical preparations Dalbron and Bakhor, so-called seed germination stimulators (SDS). Full article

(This article belongs to the Special Issue Catalytic Systems for Biomass Valorization)

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17 pages, 2033 KiB

Open AccessReview

Efficiency and Prospects of the Use of Mechanochemical Treatment to Obtain Innovative Composite Systems

by Ayagoz Bakkara, Bakhtiyar Sadykov, Anar Zhapekova, Timur Oserov, Aisulu Batkal, Ainur Khairullina and Nina Mofa

ChemEngineering 2022, 6(6), 90; https://doi.org/10.3390/chemengineering6060090 - 15 Nov 2022

Cited by 1 | Viewed by 2875

Abstract

This review is devoted to the possibilities of using mechanochemical processing and to achievements in this field for obtaining materials for a wide range of purposes. The mechanochemical processing of various materials and compositions in energy-intensive grinding devices allows the production of innovative [...] Read more.

This review is devoted to the possibilities of using mechanochemical processing and to achievements in this field for obtaining materials for a wide range of purposes. The mechanochemical processing of various materials and compositions in energy-intensive grinding devices allows the production of innovative systems, ensuring the necessary complex structure and properties. A detailed analysis of the processes of mechanochemical processing in the production of designs for various purposes is given, and the latest practical results in this area are highlighted. A detailed analysis of the processes of mechanochemical processing in the production of structures for various purposes is given, as well as recent practical results in this area, such as the use of mechanochemical processing to increase the performance of aluminum and other metals used as a combustible substance in energy-intensive systems. This review also presents the prospects for the use of mechanochemical processing to obtain physiologically active drugs from plant materials, which is an effective method for creating new materials in the field of pharmaceuticals, animal husbandry, veterinary medicine, crop production, etc. Full article

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20 pages, 3819 KiB

Open AccessFeature PaperReview

A Brief Review of Photocatalytic Reactors Used for Persistent Pesticides Degradation

by Gabriela Olimpia Isopencu, Alexandra Mocanu and Iuliana-Mihaela Deleanu

ChemEngineering 2022, 6(6), 89; https://doi.org/10.3390/chemengineering6060089 - 11 Nov 2022

Cited by 4 | Viewed by 2866

Abstract

Pesticide pollution is a major issue, given their intensive use in the 20th century, which led to their accumulation in the environment. At the international level, strict regulations are imposed on the use of pesticides, simultaneously with the increasing interest of researchers from [...] Read more.

Pesticide pollution is a major issue, given their intensive use in the 20th century, which led to their accumulation in the environment. At the international level, strict regulations are imposed on the use of pesticides, simultaneously with the increasing interest of researchers from all over the world to find methods of neutralizing them. Photocatalytic degradation is an intensively studied method to be applied for the degradation of pesticides, especially through the use of solar energy. The mechanisms of photocatalysis are studied and implemented in pilot and semi-pilot installations on experimental platforms, in order to be able to make this method more efficient and to identify the equipment that can achieve the photodegradation of pesticides with the highest possible yields. This paper proposes a brief review of the impact of pesticides on the environment and some techniques for their degradation, with the main emphasis on different photoreactor configurations, using slurry or immobilized photocatalysts. This review highlights the efforts of researchers to harmonize the main elements of photocatalysis: choice of the photocatalyst, and the way of photocatalyst integration within photoreaction configuration, in order to make the transfer of momentum, mass, and energy as efficient as possible for optimal excitation of the photocatalyst. Full article

(This article belongs to the Special Issue Photocatalytic Degradation of Organic Wastes)

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13 pages, 3705 KiB

Open AccessArticle

The Effectiveness of Polyvinylidene Fluoride Membranes Modified with Poloxamer and Single/Multi-Walled Carbon Nanotubes for Lactalbumin Purification

by Nasrul Arahman, Widia Puspita Sari, Indah Maulana Sari, Cut Meurah Rosnelly, Sri Mulyati, Afrillia Fahrina, Muhammad Roil Bilad, Poernomo Gunawan, Mehmet Emin Pasaoglu, Oğuz Orhun Teber, Vahid Vatanpour, Ismail Koyuncu and Yusni Yusni

ChemEngineering 2022, 6(6), 88; https://doi.org/10.3390/chemengineering6060088 - 10 Nov 2022

Cited by 2 | Viewed by 1647

Abstract

The application of separation technology using ultrafiltration/nanofiltration membranes for protein purification and concentration has grown rapidly in the last decade. Innovations to synthesize membranes with properties and performance that suit the characteristics of the feed solution have been and will keep developing. This [...] Read more.

The application of separation technology using ultrafiltration/nanofiltration membranes for protein purification and concentration has grown rapidly in the last decade. Innovations to synthesize membranes with properties and performance that suit the characteristics of the feed solution have been and will keep developing. This study aims to examine the strategies to improve the performance of the Polyvinylidene Fluoride (PVDF) membrane for lactalbumin protein isolation. The PVDF polymer membrane was modified by adding Poloxamer 188 (Po1) copolymer and a combination of two types of nanocarbons, i.e., single-walled carbon nanotubes (S-CnT) and multi-walled carbon nanotubes (M-CnT). The following membrane characteristics were examined: mechanical properties, morphological structure, porosity, elemental composition and functional groups, and surface hydrophilicity. The membrane’s filtration performance was analyzed in terms of its ability to pass water (flux) and concentrate lactalbumin protein. The results showed that the changes in the membrane morphological structure were clearly visible in the SEM test, which exposed more open membrane pores after adding Pol and S-CnT/M-CnT additives. The mechanical properties of the membrane also increased, as indicated by the increase in the tensile strength from 12.1 MPa to 16.07 MPa. In general, it was found that the composition of the PVDF/Pol/S-CnT/NMP polymer solutions resulted in better filtration performance compared to the membranes made of only the PVDF/NMP polymer solution. Full article

(This article belongs to the Special Issue Chemical Engineering in Nanotechnology and Nano/micromaterials Applied to Sustainable and Emergent Areas)

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8 pages, 3275 KiB

Open AccessArticle

Preparation and Photocatalytic/Photoelectrochemical Investigation of 2D ZnO/CdS Nanocomposites

by Dina Bakranova, Bekbolat Seitov and Nurlan Bakranov

ChemEngineering 2022, 6(6), 87; https://doi.org/10.3390/chemengineering6060087 - 09 Nov 2022

Cited by 1 | Viewed by 1336

Abstract

Properties of heterotructured semiconductors based on ZnO/CdS nanosheets are investigated for their possible application in photocatalytic and photoelectrochemical reactions. Semiconductor material is the main active coating of photoanodes, which triggers the half-reaction of water oxidation and reduction, which entails the purifying or splitting [...] Read more.

Properties of heterotructured semiconductors based on ZnO/CdS nanosheets are investigated for their possible application in photocatalytic and photoelectrochemical reactions. Semiconductor material is the main active coating of photoanodes, which triggers the half-reaction of water oxidation and reduction, which entails the purifying or splitting of water. This article explains nanocomposite assembly by convenient and simple methods. The study of the physicochemical properties of semiconductor layers is carried out using electron microscopy, X-ray diffractometry, and UV-visible spectroscopy. Studies of electrochemical properties are carried out by potential static methods in electrochemical cells. Full article

(This article belongs to the Special Issue Photocatalytic Degradation of Organic Wastes)

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15 pages, 3839 KiB

Open AccessArticle

Sustainable Basalt Fibers vs. Traditional Glass Fibers: Comparative Study on Thermal Properties and Flow Behavior of Polyamide 66-Based Composites

by Antonella Patti, Stefano Acierno, Luigi Nele, Lucia Graziosi and Domenico Acierno

ChemEngineering 2022, 6(6), 86; https://doi.org/10.3390/chemengineering6060086 - 04 Nov 2022

Cited by 4 | Viewed by 1825

Abstract

In this work, basalt fibers (BF) have been investigated as possible natural and sustainable replacements for the common synthetic mineral filler—glass fibers (GF)—used in polyamide 66 matrix (PA66). Composites have been prepared at two different fiber concentrations (15 and 25 wt.%, respectively) by [...] Read more.

In this work, basalt fibers (BF) have been investigated as possible natural and sustainable replacements for the common synthetic mineral filler—glass fibers (GF)—used in polyamide 66 matrix (PA66). Composites have been prepared at two different fiber concentrations (15 and 25 wt.%, respectively) by melt blending. The developed systems have been mainly characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), capillary rheology, and scanning electron microscopy (SEM). The kinetic parameters to thermal degradation through the Coats–Redfern method allowed us to attest a negligible effect of fiber type on thermal stability of the developed systems. Composites incorporating 15 wt.% of fiber content possessed the highest activation energy (≥230 kJ/mol). The introduction of BF and GF in PA 66 polymer, regardless of content, always led to an increase in crystallization and melting temperatures, and to a similar reduction in crystallinity degree and glass transition temperature. The shear viscosity of the basic polymer increased by the addition of fillers, particularly at low shear rate, with a pronounced effect in the case of basal fibers. A slightly higher shear thinning behavior of BF/PA66 with respect to GF/PA66 composites was confirmed by fitting the flow curves through the power law model. Finally, a worsening in fiber dispersion, by increasing the content in the matrix, and a weak compatibility between the two phases constituting the materials were highlighted through SEM micrographs. Full article

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12 pages, 2253 KiB

Open AccessArticle

Process Intensification in a Double-Pipe Reactor with Additively Manufactured Internal Inserts

by Sara Claramunt, Paul V. Schell, Manfred Kraut, Bruno F. Stengel, Christof F. Kuesters and Roland Dittmeyer

ChemEngineering 2022, 6(6), 85; https://doi.org/10.3390/chemengineering6060085 - 02 Nov 2022

Viewed by 1648

Abstract

The polycondensation reaction to produce polydextrose can be intensified by using micro-process engineering. Fluid Guiding Elements are additively manufactured internal inserts that have already shown their potential to intensify heat transfer in double-pipe heat exchangers. This study investigated the intensification of the polydextrose [...] Read more.

The polycondensation reaction to produce polydextrose can be intensified by using micro-process engineering. Fluid Guiding Elements are additively manufactured internal inserts that have already shown their potential to intensify heat transfer in double-pipe heat exchangers. This study investigated the intensification of the polydextrose yield when these internal inserts were used. Different reactor lengths and internal inserts geometries, as well as different operating conditions, were analyzed. The experiments showed that the reactant concentration had no effect on the product yield. Furthermore, it was shown that the process could be intensified at higher temperatures, with relatively low residence times and lower pressures. It was confirmed that the good heat transfer characteristics of the internal inserts allow them to continuously evaporate water during the reaction and to further reach the required reaction temperature, thus shifting the equilibrium towards the desired product. These findings are of special significance for the optimization of the polycondensation reaction of polydextrose. Full article

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14 pages, 2495 KiB

Open AccessArticle

Modelling of Fuel Filter Clogging of B20 Fuel Based on the Precipitate Measurement and Filter Blocking Test

by Imam Paryanto, Ilyin Abdi Budianta, Kanya Citta Hani Alifia, Ibnu Maulana Hidayatullah, Muhammad Arif Darmawan, Judistira, Tirto Prakoso, Antonius Indarto and Misri Gozan

ChemEngineering 2022, 6(6), 84; https://doi.org/10.3390/chemengineering6060084 - 02 Nov 2022

Cited by 3 | Viewed by 1647

Abstract

The amount of precipitate and residue affects the timing of fuel filter blockage. This study develops a model for fuel filter blocking based on the Precipitate Measurement. Firstly, a modification of ASTM D 7501 for the Cold Soak Filtration Test (CSFT) measured the [...] Read more.

The amount of precipitate and residue affects the timing of fuel filter blockage. This study develops a model for fuel filter blocking based on the Precipitate Measurement. Firstly, a modification of ASTM D 7501 for the Cold Soak Filtration Test (CSFT) measured the amount of precipitate in B20 fuel with variations of soaking temperatures and monoglyceride content in biodiesel. Then, a modified ASTM D 2068 for a filter blocking test (FBT) was conducted to correlate the impurities in the B20 fuel and the clogging limit effects represented by the change of pressure difference and time to reach a pressure drop of 30 kPa. Biodiesel B20 samples were prepared by adding monopalmitin so that each had a monoglyceride value of 0.2%, 0.4%, 0.6%, and 0.8% before blending with petroleum diesel. The modified CSFT showed that the amount of B0 impurity was almost zero. However, the amount of the B20 sample precipitate retained on the filter was higher when a lower soaking temperature and higher monoglyceride content was used in the biodiesel. Similar results in the modified FBT showed that the more impurities, the faster the pressure drop achieved a level of 30 kPa. A much shorter time was needed to reach the pressure drop of 30 kPa for B20 fuel samples with the impurities present in both test powders and precipitate compared to those for the B20 fuel samples with a single type of impurity (either test powders or precipitate). The fuel filter clogging time could also be predicted using the graph of fuel filter clogging time vs. the precipitate weight of B20 fuel derived from the FBT test if the precipitate weight had already been determined by the precipitation test (modified CSFT). The simulation model using Ergun’s equation for the FBT of the B20 fuel could also show similar results to that of the FBT experiment, with the difference (averaged errors) ranging from 4.15% to 5.79%. Full article

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ChemEngineering, Volume 6, Issue 6 (December 2022) – 15 articles

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