ChemEngineering

19 pages, 3615 KiB

Open AccessArticle

Factors That Determine the Adhesive Strength in a Bioinspired Bone Tissue Adhesive

by Michael Pujari-Palmer, Roger Giró, Philip Procter, Alicja Bojan, Gerard Insley and Håkan Engqvist

ChemEngineering 2020, 4(1), 19; https://doi.org/10.3390/chemengineering4010019 - 21 Mar 2020

Cited by 10 | Viewed by 3376

Abstract

Phosphoserine-modified cements (PMCs) are a family of wet-field tissue adhesives that bond strongly to bone and biomaterials. The present study evaluated variations in the adhesive strength using a scatter plot, failure mode, and a regression analysis of eleven factors. All single-factor, continuous-variable correlations [...] Read more.

Phosphoserine-modified cements (PMCs) are a family of wet-field tissue adhesives that bond strongly to bone and biomaterials. The present study evaluated variations in the adhesive strength using a scatter plot, failure mode, and a regression analysis of eleven factors. All single-factor, continuous-variable correlations were poor (R² < 0.25). The linear regression model explained 31.6% of variation in adhesive strength (R² = 0.316 p < 0.001), with bond thickness predicting an 8.5% reduction in strength per 100 μm increase. Interestingly, PMC adhesive strength was insensitive to surface roughness (S_a 1.27–2.17 μm) and the unevenness (skew) of the adhesive bond (p > 0.167, 0.171, ANOVA). Bone glued in conditions mimicking the operating theatre (e.g., the rapid fixation and minimal fixation force in fluids) produced comparable adhesive strength in laboratory conditions (2.44 vs. 1.96 MPa, p > 0.986). The failure mode correlated strongly with the adhesive strength; low strength PMCs (<1 MPa) failed cohesively, while high strength (>2 MPa) PMCs failed adhesively. Failure occurred at the interface between the amorphous surface layer and the PMC bulk. PMC bonding is sufficient for clinical application, allowing for a wide tolerance in performance conditions while maintaining a minimal bond strength of 1.5–2 MPa to cortical bone and metal surfaces. Full article

(This article belongs to the Special Issue Material and Structural Design of Novel Adhesives and Adhesive Systems)

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11 pages, 3641 KiB

Open AccessArticle

Indirect Dryers for Biomass Drying—Comparison of Experimental Characteristics for Drum and Rotary Configurations

by Jan Havlík and Tomáš Dlouhý

ChemEngineering 2020, 4(1), 18; https://doi.org/10.3390/chemengineering4010018 - 10 Mar 2020

Cited by 12 | Viewed by 7271

Abstract

This paper focuses on indirect biomass drying. It compares the operating characteristics of a laboratory-scale drum dryer and a pilot-scale rotary dryer. Before the design of an industrial dryer for a specific material, it is important to experimentally prove the process and to [...] Read more.

This paper focuses on indirect biomass drying. It compares the operating characteristics of a laboratory-scale drum dryer and a pilot-scale rotary dryer. Before the design of an industrial dryer for a specific material, it is important to experimentally prove the process and to determine the drying characteristics of the material. To verify the portability of experimental results for indirect dryers, a drum dryer with indirect electric heating in a laboratory scale was designed and built to test and study the process of indirect drying. Based on the results obtained on a small-scale device, a prototype of a pilot steam-heated rotary dryer was designed and manufactured. A broad range of experiments with green wood chips and wet bark from open-air storage with moisture contents of 50 to 65 wt % were carried out on both dryers. The drying curves indicating the process, the square and volumetric evaporation capacities, and the drying energy consumption were obtained and compared, and the feasibility of indirect drying for these tested types of biomass was confirmed. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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4 pages, 219 KiB

Open AccessEditorial

Special Issue “Advances in Biogas Desulfurization”

by Martín Ramírez

ChemEngineering 2020, 4(1), 17; https://doi.org/10.3390/chemengineering4010017 - 09 Mar 2020

Cited by 6 | Viewed by 2578

Abstract

This Special Issue contains three articles and two reviews. The biological reactors used in the studies were fed with real biogas from Landfill or STPs. One research article concerns the use of a pilot scale plant with a combined process with a chemical [...] Read more.

This Special Issue contains three articles and two reviews. The biological reactors used in the studies were fed with real biogas from Landfill or STPs. One research article concerns the use of a pilot scale plant with a combined process with a chemical and biological system. The other two studies concern anoxic biotrickling filters, with one study focused on the study of variable operation and its optimization through the response surface methodology, and the other focused on the selection of packing material. The reviews concern the current state of biogas desulfurization technologies, including an economic analysis, and the microbial ecology in biofiltration units. This Issue highlights some of the most relevant aspects about biogas desulfurization. Full article

(This article belongs to the Special Issue Advances in Biogas Desulfurization)

14 pages, 4994 KiB

Open AccessArticle

Dry Reforming of Methane over a Ruthenium/Carbon Nanotube Catalyst

by Yuan Zhu, Kun Chen, Robert Barat and Somenath Mitra

ChemEngineering 2020, 4(1), 16; https://doi.org/10.3390/chemengineering4010016 - 09 Mar 2020

Cited by 6 | Viewed by 3250

Abstract

In this study, CH₄ dry reforming was demonstrated on a novel microwave-synthesized ruthenium (Ru)/carbon nanotube (CNT) catalyst. The catalyst was tested in an isothermal laboratory-packed bed reactor, with gas analysis by gas chromatography/thermal conductivity detection. The catalyst demonstrated excellent dry-reforming activity at [...] Read more.

In this study, CH₄ dry reforming was demonstrated on a novel microwave-synthesized ruthenium (Ru)/carbon nanotube (CNT) catalyst. The catalyst was tested in an isothermal laboratory-packed bed reactor, with gas analysis by gas chromatography/thermal conductivity detection. The catalyst demonstrated excellent dry-reforming activity at modest temperatures (773–973 K) and pressure (3.03 × 10⁵ Pa). Higher reaction temperatures favored increased conversion of CH₄ and CO₂, and increased H₂/CO product ratios. Slight coke deposition, estimated by carbon balance, was observed at higher temperatures and higher feed CH₄/CO₂. A robust global kinetic model composed of three reversible reactions—dry reforming, reverse water gas shift, and CH₄ decomposition—simulates observed outlet species concentrations and reactant conversions using this Ru/CNT catalyst over the temperature range of this study. This engineering kinetic model for the Ru/CNT catalyst predicts a somewhat higher selectivity and yield for H₂, and less for CO, in comparison to previously published results for a similarly prepared Pt_Pd/CNT catalyst from our group. Full article

(This article belongs to the Special Issue Advanced Functional Low-dimensional Materials and Their Applications)

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9 pages, 986 KiB

Open AccessArticle

Integrated and Networked Systems and Processes—A Perspective for Digital Transformation in Thermal Process Engineering

by Michael Maiwald

ChemEngineering 2020, 4(1), 15; https://doi.org/10.3390/chemengineering4010015 - 04 Mar 2020

Cited by 5 | Viewed by 2642

Abstract

Separation technology as a sub-discipline of thermal process engineering is one of the most critical steps in the production of chemicals, essential for the quality of intermediate and end products. The discipline comprises the construction of facilities that convert raw materials into value-added [...] Read more.

Separation technology as a sub-discipline of thermal process engineering is one of the most critical steps in the production of chemicals, essential for the quality of intermediate and end products. The discipline comprises the construction of facilities that convert raw materials into value-added products along the value chain. Conversions typically take place in repeated reaction and separation steps—either in batch or continuous processes. The end products are the result of several production and separation steps that are not only sequentially linked, but also include the treatment of unused raw materials, by-products and wastes. Production processes in the process industry are particularly susceptible to fluctuations in raw materials and other influences affecting product quality. This is a challenge, despite increasing fluctuations, to deliver targeted quality and simultaneously meet the increasing dynamics of the market, at least for high value fine chemicals. In order to survive successfully in a changed environment, chemical companies must tread new paths. This includes the potential of digital technologies. The full integration and intelligent networking of systems and processes is progressing hesitantly. This contribution aims to encourage a more holistic approach to the digitalization in thermal process engineering by introduction of integrated and networked systems and processes. Full article

(This article belongs to the Special Issue Progress in Thermal Process Engineering)

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13 pages, 1976 KiB

Open AccessArticle

Column Separation of Am(III) and Eu(III) by α-Zirconium Phosphate Ion Exchanger in Nitric Acid

by Elmo W. Wiikinkoski, Iiro Rautsola, Junhua Xu and Risto Koivula

ChemEngineering 2020, 4(1), 14; https://doi.org/10.3390/chemengineering4010014 - 24 Feb 2020

Cited by 1 | Viewed by 2095

Abstract

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline [...] Read more.

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline α-zirconium phosphate ion exchanger was utilized for Eu(III)/Am(III) column separation. Comprehensive preliminary studies were done using batch experiments to optimize the final separation conditions. The distribution coefficients for Eu were determined as a function of pH (from 0 to 3) and salinity (Na, Sr). The distribution coefficients for Am were determined as a function of pH, and Eu concentration, from 1:40 to 10,000:1 Eu:Am molar ratio. The exchanger always preferred Eu over Am in our experimental conditions. Separation factors (Eu:Am) of up to 400 were achieved in binary Eu-Am solution in pH 1. The breakthrough capacity was determined in dynamic column conditions using Eu: 0.3 meq∙g⁻¹, which is approximately 4% of the theoretical maximum capacity. Two types of hot column separation tests were conducted: (i) binary load (selective Am elution), and (ii) continuous equimolar binary feed. In both cases separation was achieved. In (i), the majority (82% of the recovered 93%) of Am could be purified from Eu with extremely high 99.999% molar purity, while alternatively even more (95% of the recovered 93%) at a lower purity of 99.7 mol %. In (ii), up to 330 L∙kg⁻¹ of the equimolar solution per mass of the exchanger could be treated with Am purity above 99.5 mol % in the total eluate. Alternatively, up to 630 L∙kg⁻¹ above 95 mol %, or up to 800 L∙kg⁻¹ above 90 mol % purities. Full article

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14 pages, 1029 KiB

Open AccessArticle

A Numerical Implementation of the Soret Effect in Drying Processes

by Bartolomeus Häussling Löwgren, Julius Bergmann and Odilio Alves-Filho

ChemEngineering 2020, 4(1), 13; https://doi.org/10.3390/chemengineering4010013 - 17 Feb 2020

Cited by 1 | Viewed by 2560

Abstract

Drying of porous media is strictly governed by heat and mass transfer. However, contrary to the definition that drying is simultaneous transport mechanisms of heat and mass, most past and current models either account for temperature or concentration gradient effects on drying. Even [...] Read more.

Drying of porous media is strictly governed by heat and mass transfer. However, contrary to the definition that drying is simultaneous transport mechanisms of heat and mass, most past and current models either account for temperature or concentration gradient effects on drying. Even though the complexity of computations of these processes varies with area of application, in most cases, the Dufour and Soret effects are neglected. This leads to deviations and uncertainties on the assumptions and interpretations of these and other relevant effects on drying. This paper covers the theoretical methods to derive the coupled transfer effects. In addition, this work proposes and formulates relevant heat and mass transfer equations, as well as the governing equations for drying processes with Dufour and Soret effects. The application of a numerical approach to solve the equations allows for studying of the influence of these effects on the design and operation of dryers. It is shown that the Soret effect can be highly relevant on drying operations with dynamic heating operation. While for drying processes where the steady state drying process predominates, the effect is deemed negligible. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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12 pages, 283 KiB

Open AccessArticle

The Influence of Maltodextrin and Inulin on the Physico-Chemical Properties of Cranberry Juice Powders

by Anna Michalska-Ciechanowska, Joanna Majerska, Jessica Brzezowska, Aneta Wojdyło and Adam Figiel

ChemEngineering 2020, 4(1), 12; https://doi.org/10.3390/chemengineering4010012 - 17 Feb 2020

Cited by 19 | Viewed by 4133

Abstract

Cranberry juice has a high content of polyphenols, which makes it a valuable raw material with health-promoting properties. On the other hand, the bitter and astringent taste of cranberry limits its consumption in fresh form (fruit, juice). For this reason, new formulations of [...] Read more.

Cranberry juice has a high content of polyphenols, which makes it a valuable raw material with health-promoting properties. On the other hand, the bitter and astringent taste of cranberry limits its consumption in fresh form (fruit, juice). For this reason, new formulations of cranberry products based on natural additives are sought, e.g., in the form of carriers, which not only allow the drying of liquids to form powders, but which can also affect the retention of bioactive compounds. This study aimed at the evaluation of the influence of different carriers and concentrations applied to cranberry juice and their influence on the physico-chemical properties of the powders obtained. Freeze-dried powders had approximately eight times higher moisture content than products gained after the spray-drying process. The bulk density of freeze-dried product was approximately 11% higher when compared to spray-drying. Freeze-drying and spray-drying had a similar influence on the total polyphenolic compound content and antioxidant capacity. When the concentration of carriers was concerned, it was indicated that a higher content of carrier resulted in a lower moisture content, water activity, CIE L*a*b* coordinates, total polyphenolic content, and antioxidant capacity of the powders obtained, pointing to a strong influence of the juice composition on the final properties of the powders. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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21 pages, 1944 KiB

Open AccessArticle

Applied Process Simulation-Driven Oil and Gas Separation Plant Optimization Using Surrogate Modeling and Evolutionary Algorithms

by Anders Andreasen

ChemEngineering 2020, 4(1), 11; https://doi.org/10.3390/chemengineering4010011 - 06 Feb 2020

Cited by 10 | Viewed by 4600

Abstract

In this article, the optimization of a realistic oil and gas separation plant has been studied. Using Latin Hypercube Sampling (LHS) and rigorous process simulations, surrogate models using Kriging have been established for selected model responses. The surrogate models are used in combination [...] Read more.

In this article, the optimization of a realistic oil and gas separation plant has been studied. Using Latin Hypercube Sampling (LHS) and rigorous process simulations, surrogate models using Kriging have been established for selected model responses. The surrogate models are used in combination with an evolutionary algorithm for optimizing the operating profit, mainly by maximizing the recoverable oil production. A total of 10 variables representing pressure and temperature at various key places in the separation plant are optimized to maximize the operational profit. The optimization is bounded in the variables and a constraint function is included to ensure that the optimal solution allows export of oil with a Reid Vapor Pressure (RVP) < 12 psia. The main finding is that, while a high pressure is preferred in the first separation stage, apparently a unique optimal setting for the pressure in downstream separators does not appear to exist. In the second stage separator, apparently different, yet more or less equally optimal, settings are revealed. In the third and final separation stage a correlation between the separator pressure and the applied inlet temperature exists, where different combinations of pressure and temperature yields equally optimal results. Full article

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13 pages, 4896 KiB

Open AccessFeature PaperArticle

Obtaining Mn-Co Alloys in AISI 430 Steel from Lithium-Ion Battery Recycling: Application in SOFC Interconnectors

by Sicele L. A. Gonçalves, Eric M. Garcia, Hosane A. Tarôco and Tulio Matencio

ChemEngineering 2020, 4(1), 10; https://doi.org/10.3390/chemengineering4010010 - 05 Feb 2020

Cited by 3 | Viewed by 2165

Abstract

The recycling of exhausted lithium-ion batteries from mobile phones originate five solutions with different Co and Mn proportions that were used as electrolytic solutions to obtain Mn-Co spinel coatings on the surface of AISI430 stainless steel. The coatings are intended to contain chromium [...] Read more.

The recycling of exhausted lithium-ion batteries from mobile phones originate five solutions with different Co and Mn proportions that were used as electrolytic solutions to obtain Mn-Co spinel coatings on the surface of AISI430 stainless steel. The coatings are intended to contain chromium volatility in the working conditions of Solid Oxide Fuel Cells (SOFC) metallic interconnectors. Potentiostatic electrodeposition was the technique used to obtain Mn-Co coatings from low concentration electrolytes at pH = 3.0 and potential applied −1.3 V. Charge efficiency data were used for sample optimization. Three optimized samples were subjected to oxidation heat treatment at 800 °C for 300 h and then characterized by XRD, SEM and EDS. The results showed that the addition of manganese ions instead of cobalt ions in the electrolytic bath produces more stable and well-distributed deposits as the ratio of the two ions becomes equal in the electrolytic bath. Thin, homogeneous and stable spinel coatings (Mn, Co)₃O₄ 2.8 μm and 3.9 μm thick were able to block chromium volatility when exposed to SOFC operating temperature. Full article

(This article belongs to the Special Issue 2019 HYPOTHESIS XIV)

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14 pages, 6337 KiB

Open AccessArticle

Drying-Induced Strain-Stress and Deformation of Thin Ceramic Plate

by Yoshinori Itaya, Hiroya Hanai, Nobusuke Kobayashi and Tsuguhiko Nakagawa

ChemEngineering 2020, 4(1), 9; https://doi.org/10.3390/chemengineering4010009 - 01 Feb 2020

Cited by 5 | Viewed by 2276

Abstract

Ceramic thin plates are applied to several industrial purposes including electronic materials and sensors. Drying-induced shrinkage and strain-stress formation of a ceramic thin plate were studied experimentally and theoretically. A kaolin thin plate molded into 10 mm × 30 mm × 1 mm [...] Read more.

Ceramic thin plates are applied to several industrial purposes including electronic materials and sensors. Drying-induced shrinkage and strain-stress formation of a ceramic thin plate were studied experimentally and theoretically. A kaolin thin plate molded into 10 mm × 30 mm × 1 mm was dried in a hot air stream, and the drying characteristics and deformation were examined. Modeling was also performed to predict the behavior. Heat and moisture transfer conservation equations and constitution equations based on viscoelastic strain-stress were simultaneously solved by a finite element method. A test piece of the thin plate was warped when only one side of the plate was dried, while it was almost flat when both sides were dried. The behaviors of drying and deformation were predicted with a reasonable agreement by the modeling. Parametric analyses by the modeling revealed that the drying conditions with faster drying rate in the beginning period resulted in formation of greater maximum principal stress, and drying on only one side of the plate induced stronger tensile stress in falling rate period than that with both sides drying. The larger thickness of the plate influenced the formation of significantly greater tensile stress but affected maximum compressive stress only a little. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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13 pages, 2472 KiB

Open AccessArticle

High End Quality Measuring in Mango Drying through Multi-Spectral Imaging Systems

by Katrin Jödicke, Robin Zirkler, Timo Eckhard, Werner Hofacker and Bernd Jödicke

ChemEngineering 2020, 4(1), 8; https://doi.org/10.3390/chemengineering4010008 - 01 Feb 2020

Cited by 4 | Viewed by 2326

Abstract

In modern fruit processing technology, non-destructive quality measuring techniques are sought for determining and controlling changes in the optical, structural, and chemical properties of the products. In this context, changes inside the product can be measured during processing. Especially for industrial use, fast, [...] Read more.

In modern fruit processing technology, non-destructive quality measuring techniques are sought for determining and controlling changes in the optical, structural, and chemical properties of the products. In this context, changes inside the product can be measured during processing. Especially for industrial use, fast, precise, but robust methods are particularly important to obtain high-quality products. In this work, a newly developed multi-spectral imaging system was implemented and adapted for drying processes. Further it was investigated if the system could be used to link changes in the surface spectral reflectance during mango drying with changes in moisture content and contents of chemical components. This was achieved by recovering the spectral reflectance from multi-spectral image data and comparing the spectral changes with changes of the total soluble solids (TSS), pH-value and the relative moisture content x_wb of the products. In a first step, the camera was modified to be used in drying, then the changes in the spectra and quality criteria during mango drying were measured. For this, mango slices were dried at air temperatures of 40–80 °C and relative air humidities of 5%–30%. Samples were analyzed and pictures were taken with the multi-spectral imaging system. The quality criteria were then predicted from spectral data. It could be shown that the newly developed multi-spectral imaging system can be used for quality control in fruit drying. There are strong indications as well, that it can be employed for the prediction of chemical quality criteria of mangoes during drying. This way, quality changes can be monitored inline during the process using only one single measuring device. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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4 pages, 168 KiB

Open AccessEditorial

Acknowledgement to Reviewers of ChemEngineering in 2019

by ChemEngineering Editorial Office

ChemEngineering 2020, 4(1), 7; https://doi.org/10.3390/chemengineering4010007 - 21 Jan 2020

Viewed by 1406

Abstract

The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial[...] Full article

17 pages, 2844 KiB

Open AccessArticle

Economic Evaluation of Drying of Soot Sludge and Sawdust Mixture at Low Temperatures Using the Characteristic Drying Curve Method

by Tiina Myllymaa, Henrik Holmberg and Pekka Ahtila

ChemEngineering 2020, 4(1), 6; https://doi.org/10.3390/chemengineering4010006 - 12 Jan 2020

Cited by 3 | Viewed by 2419

Abstract

Soot sludge is a waste stream formed in the fuel oil gasification of formic acid and hydrogen peroxide production. The soot sludge has a high moisture content (95%) and is presently combusted with heavy fuel oil in order to dispose of the sludge. [...] Read more.

Soot sludge is a waste stream formed in the fuel oil gasification of formic acid and hydrogen peroxide production. The soot sludge has a high moisture content (95%) and is presently combusted with heavy fuel oil in order to dispose of the sludge. Experimental tests earlier conducted by the authors have shown that the sludge can be convectively dried with sawdust in a fixed bed. By upgrading the sludge from waste to fuel, the utilization of oil can be decreased. In this study, characteristic drying curves (CDC) are determined for the sludge and sawdust mixture. The CDCs are further used to evaluate the economy of the mixture drying in a belt dryer by using the payback period method. Results show that the linear CDCs of the mixture can be used to extrapolate drying data from specific drying conditions to another when the bed height is 200 or 300 mm, and the inlet air temperature 40–100 °C. The economic analysis shows that drying is economical for all inlet air temperatures if the oil price is ≥350 €/t-oil. Sensitivity analyses reveal that the heat, sawdust and emission prices have no remarkable influence on the economy of drying if the oil price does not fall below c. 300 €/t-oil. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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25 pages, 2325 KiB

Open AccessFeature PaperArticle

Structural, Thermodiffusive and Thermoelectric Properties of Maghemite Nanoparticles Dispersed in Ethylammonium Nitrate

by Kakoli Bhattacharya, Mitradeep Sarkar, Thomas J. Salez, Sawako Nakamae, Gilles Demouchy, Fabrice Cousin, Emmanuelle Dubois, Laurent Michot, Régine Perzynski and Véronique Peyre

ChemEngineering 2020, 4(1), 5; https://doi.org/10.3390/chemengineering4010005 - 08 Jan 2020

Cited by 17 | Viewed by 3805

Abstract

Ethylammonium nitrate (ionic liquid) based ferrofluids with citrate-coated nanoparticles and Na

^{+}

counterions were synthesized for a wide range of nanoparticle (NP) volume fractions (

Φ

) of up to 16%. Detailed structural analyses on these fluids were performed using magneto-optical birefringence and [...] Read more.

Ethylammonium nitrate (ionic liquid) based ferrofluids with citrate-coated nanoparticles and Na

^{+}

counterions were synthesized for a wide range of nanoparticle (NP) volume fractions (

Φ

) of up to 16%. Detailed structural analyses on these fluids were performed using magneto-optical birefringence and small angle X-ray scattering (SAXS) methods. Furthermore, the thermophoretic and thermodiffusive properties (Soret coefficient

S_{T}

and diffusion coefficient

D_{m}

) were explored by forced Rayleigh scattering experiments as a function of T and

Φ

. They were compared to the thermoelectric potential (Seebeck coefficient, Se) properties induced in these fluids. The results were analyzed using a modified theoretical model on

S_{T}

and Se adapted from an existing model developed for dispersions in more standard polar media which allows the determination of the Eastman entropy of transfer (

{\hat{S}}_{NP}

) and the effective charge (

Z_{0}^{e f f}

) of the nanoparticles. Full article

(This article belongs to the Special Issue Coupling Flow Behaviors and Physico-Chemical Properties of Concentrated Colloidal Particle Suspensions)

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12 pages, 1267 KiB

Open AccessFeature PaperArticle

Clean Syn-Fuels via Hydrogenation Processes: Acidity–Activity Relationship in O-Xylene Hydrotreating

by Alessandra Palella, Katia Barbera, Francesco Arena and Lorenzo Spadaro

ChemEngineering 2020, 4(1), 4; https://doi.org/10.3390/chemengineering4010004 - 06 Jan 2020

Cited by 2 | Viewed by 2845

Abstract

Transition metal sulfide catalysts are actually the most performing catalytic materials in crude oil hydrotreating (HDT), for energetic purposes. However, these systems suffer from several drawbacks that limit their exploitation. Aiming to meet the even more stringent environmental requirement, through a remarkable improvement [...] Read more.

Transition metal sulfide catalysts are actually the most performing catalytic materials in crude oil hydrotreating (HDT), for energetic purposes. However, these systems suffer from several drawbacks that limit their exploitation. Aiming to meet the even more stringent environmental requirement, through a remarkable improvement of HDT performance in the presence of refractory feedstock (i.e., in terms of activity, selectivity, and stability), a deeper knowledge of the structure–activity relationship of catalysts must be achieved. Therefore, in this study, CoMo/γ-Al₂O₃ and NiMo/γ-Al₂O₃ catalysts were characterized and tested in the o-xylene hydrogenation model reaction, assessing the influence of both support acidity and catalyst acid strength on reaction pathway by employing γ-Al₂O₃ and Y-Type zeolite as acid reference materials. A clear relationship between concentration and strength of acid sites and the performance of the catalytic materials was established. Cobalt based catalyst (CoMoS_x) proves a higher acidic character with respect to Nickel (NiMoS_x), prompting isomerization reactions preferentially, also reflecting a greater o-xylene conversion. The different chemical properties of metals also affect the catalytic pathway, leading on the CoMoS_x system to the preferential formation of p-xylene isomer with respect to m-xylene. Full article

(This article belongs to the Special Issue 2019 HYPOTHESIS XIV)

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11 pages, 2166 KiB

Open AccessArticle

Using Lignin to Modify Starch-Based Adhesive Performance

by Anahita Nasiri, Jim Wearing and Marc A. Dubé

ChemEngineering 2020, 4(1), 3; https://doi.org/10.3390/chemengineering4010003 - 06 Jan 2020

Cited by 15 | Viewed by 7003

Abstract

Unmodified kraft lignin was used to create a starch-based adhesive via the Stein Hall process. Lignin up to 35 wt% was used in several formulations. Lignin was incorporated in both the carrier and slurry portions of the formulations and the effect on adhesive [...] Read more.

Unmodified kraft lignin was used to create a starch-based adhesive via the Stein Hall process. Lignin up to 35 wt% was used in several formulations. Lignin was incorporated in both the carrier and slurry portions of the formulations and the effect on adhesive strength and water resistance was studied. The addition of lignin resulted in a significant increase in adhesive strength when the lignin was added solely to the slurry portion. When lignin was added solely to the carrier portion, the adhesive strength decreased. Other formulations, where lignin was present in both the carrier and slurry portions, showed moderate increases in adhesive strength. Finally, the addition of lignin increased the water-resistance of the adhesive bond in the paperboard. Full article

(This article belongs to the Special Issue Material and Structural Design of Novel Adhesives and Adhesive Systems)

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18 pages, 3222 KiB

Open AccessArticle

Heterogeneous Phases Reaction Equilibrium in an Oxy-Thermal Carbide Furnace

by Wenjie Xiong, Xiaohui Chen, Quanyong Wang, Min Gao, Danxing Zheng, Yuliang Mai and Wei Hu

ChemEngineering 2020, 4(1), 2; https://doi.org/10.3390/chemengineering4010002 - 03 Jan 2020

Cited by 2 | Viewed by 2780

Abstract

This work focuses on revealing the chemical reaction equilibrium behaviors of gas–liquid–solid heterogeneous phases in an oxy-thermal carbide furnace. From a CaC₂ formation mechanism investigation, it was determined that a one-step mechanism occurs when there is an excess of C and a [...] Read more.

This work focuses on revealing the chemical reaction equilibrium behaviors of gas–liquid–solid heterogeneous phases in an oxy-thermal carbide furnace. From a CaC₂ formation mechanism investigation, it was determined that a one-step mechanism occurs when there is an excess of C and a high CO partial pressure, which inhibits the formation of Ca in the system, and a two-step mechanism occurs when there is insufficient C and a low CO partial pressure, which promotes the formation of Ca. Based on the calculated results of the equilibrium compositions at 100 kPa and different temperature conditions, the chemical reaction equilibrium behaviors of gas–liquid–solid heterogeneous phases in an oxy-thermal carbide furnace were analyzed at conditions of excess C and insufficient C. Full article

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8 pages, 3421 KiB

Open AccessArticle

Flavor Release from Spray-Dried Powders with Various Wall Materials

by Shisei Takashige, Hermawan Dwi Ariyanto, Shuji Adachi and Hidefumi Yoshii

ChemEngineering 2020, 4(1), 1; https://doi.org/10.3390/chemengineering4010001 - 28 Dec 2019

Cited by 5 | Viewed by 3288

Abstract

By using the ramping method for humidity at a constant temperature, the release rates of d-limonene were investigated from spray-dried powders with various wall materials, such as maltodextrin (MD) (dextrose equivalent (DE) = 25 and 19), lactose (Lac), and sucrose (Suc). Spray-dried [...] Read more.

By using the ramping method for humidity at a constant temperature, the release rates of d-limonene were investigated from spray-dried powders with various wall materials, such as maltodextrin (MD) (dextrose equivalent (DE) = 25 and 19), lactose (Lac), and sucrose (Suc). Spray-dried powders, which were sieved to the average powder size of 107–140 µm, contained d-limonene at about 90–97 mg/g-dry powder. d-limonene release profile was measured using a dynamic vapor sorption (DVS) system coupled gas chromatography at 30, 40, and 50 °C from 10% to 90% relative humidity (RH). The linear correlation was found between the release start humidity, sRH, of d-limonene release from the powder and the glass transition temperature of wall materials. The release rates for Suc and Lac increased rapidly at certain humidities and became the maximum rates. Then, these rates decreased gradually with increasing RH. This might have been due to the powder aggregation for Suc and to crystallization for Lac. The release behaviors significantly depended on the wall materials. Full article

(This article belongs to the Special Issue Selected papers from the Third Nordic Baltic Drying Conference (NBDC 2019))

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ChemEngineering, Volume 4, Issue 1 (March 2020) – 19 articles

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