The article deals with the recent developments in the fuel industry, considering the permanent increasing requirements for fuel quality and environmental safety. The work aims to study various technological modes at the rectification unit to produce fuel bioethanol from lignocellulosic biomass. The main goals are to solve applied scientific problems of rational designing and technological optimization to obtain boundaries of energy consumption to ensure the quality of bioethanol sufficient for a consumer. Recent approaches for numerical simulation of chemical technological processes were applied to study the operating processes and optimize technological parameters. The plant model was designed from various modules that allow us to simulate technological processes efficiently and accurately for all the primary units of the rectification equipment. The methodology based on the activity coefficient UNIFAC model of phase equilibrium was applied. As a result, a mixture with 74% of bioethan... [more]

Adjusting the thermal response properties of a polymeric compound can significantly improve the usability in a selective laser-sintering process. As previously shown, combining a precise amount of coarse and narrow size distribution fine calcium carbonate fillers results in a potential optimization of the thermal properties of a polyamide 12 matrix. Additionally, up to 60% of the normally associated lost ductility can be re-gained by surface modification, thus functionalizing the filler. To optimize the functionality further this study combines a precisely defined particle size ratio of fillers adopting a specially selected surface modification using amino hexanoic acid. Morphology of the carbonate filler was also investigated. The range of effect of each parameter on the thermal response and mechanical properties was studied. The results show that the thermal properties have large potential to be optimized, without reducing the ductility significantly, by adjusting the morphology and... [more]

In the present work, the preparation of activated carbon pellets from cigarette butts by thermal treatment was evaluated. The morphological, textural, topological, and surface chemical properties were studied by SEM-EDX, N2 adsorption, Raman, and FTIR spectroscopy. For adsorption assays, activated carbon was tested for the adsorption of phenol as a model molecule at different solution pH, temperature, and type of water. In addition, leaching tests before and after carbonization were conducted to evaluate the lixiviation of ions present in the solid. The results revealed a microporous material, composed of cylindrical fibers (thickness of 13 µm) with a microporous area of 713 m2/g and narrow and uniform slit-shaped pores (0.4−0.8 nm). The surface chemistry analysis evidenced the presence of oxygenated groups (carboxylic, esters, and phenolics). Activated carbon leaching tests indicated that the concentrations of the leached ions did not exceed the maximum permissible limit for drinking... [more]

Plastic pollution is a global issue that is approaching crisis levels as plastic production is projected to reach 1.1 GT annually by 2050. The bioplastic industry along with a circular production economy are solutions to this problem. One promising bioplastic polylactic acid (PLA) has mechanical properties comparable to polystyrene (PS), so it could replace PS in its applications as a more environmentally sustainable material. However, since the bioplastic PLA also suffers from long biodegradation times in the environment, to ensure that it does not add to the current pollution problem, it should instead be chemically recycled. In this work, PLA was chemically recycled via alcoholysis, using either methanol or ethanol to generate the value-added products methyl lactate and ethyl lactate respectively. Two catalysts, zinc acetate dihydrate (ZnAc) and 4-(dimethylamino)pyridine (DMAP), were tested both individually and in mixtures. A synergistic effect was exhibited on the reaction rate wh... [more]

To better understand pyrolysis for upscaling purposes, a kinetic characterization of the process is necessary for every feedstock. Laboratory experiments allow identification of apparent kinetic models. This paper aims at the apparent kinetic investigation of peach seeds’ slow pyrolysis. Peach seeds from Greek peach fruits pyrolyzed under inert atmospheric conditions at different temperatures (475−785 °C), heating rates (100−250 °C/min) and N2 flow rates (25−200 cc/min). Prior to pyrolysis, they submitted to hexane extraction for the recovery of 36.8% wt. of the contained oils. Determination of the specific rate constant (k) and activation energy (Ea) for each considered reaction was made by using the Coats−Redfern integral non-isothermal fitting model that requires an assumption of the reaction order (n). Results revealed that a 3rd order reaction model best fits the process, the increasing of the pyrolysis temperature leads to a decrease of the activation energy (E) and pre-exponenti... [more]

In the current numerical study, various wall shape effects are investigated on the thermal-hydraulic characteristics of different channels filled with water-based graphite-SiO2 hybrid nanofluid. In this work, the performance evaluation criteria (PEC) index is employed as the target parameter to attain optimum geometry. Six different cases are studied in this research, and each case has different geometrical dimensions. The inlet temperature for the fluids in the channel is 300 K, over a range of different flow velocities. According to the obtained results, an increase in the volume fraction of nanoparticles results in higher PEC values. In addition, an increase in Reynolds number to Re = leads to an increase in the PEC index. The results clearly show that increasing the Reynolds number has two consequences: on the one hand, it increases the pressure drop penalty; on the other hand, it improves heat transfer. Therefore, the maximum value of the PEC index occurs at Re = 15,000.

The aim of this work is to identify the effect of the CaO phase as a CO2 sorbent and mayenite (Ca12Al14O33) as a stabilizing phase in a bi-functional material for CO2 capture in biomass syngas conditioning and cleaning at high temperature. The effect of different CaO weight contents is studied (0, 56, 85, 100 wt%) in sorbents synthesized by the wet mixing method. These high temperature solid sorbents are upgraded to bi-functional compounds by the addition of 3 or 6 wt% of nickel chosen as the metal active phase. N2 adsorption, X-ray diffraction, scanning electronic microscopy, temperature-programmed reduction analyses and CO2 sorption study were performed to characterize structural, textural, reducibility and sorption properties of bi-functional materials. Finally, sorption-enhanced reforming of toluene (chosen as tar model), of methane then of methane and toluene with bi-functional compounds were performed to study the best material to improve H2 content in a syngas, provided by steam... [more]

Tea polyphenols (TP) are a widely acknowledged bioactive natural product, however, low stability and bioavailability have restricted their application in many fields. To enhance the stability and bioavailability of TP under certain moderate conditions, encapsulation technique was applied. Kappa−Carrageenan (KCG) was initially degraded to a lower molecular weight KCG (LKCG) by H2O2, and was selected as wall material to coat TP. The obtained LKCG (Mn = 13,009.5) revealed narrow dispersed fragments (DPI = 1.14). FTIR and NMR results demonstrated that the main chemical structure of KCG remained unchanged after degradation. Subsequently, LK-CG and TP were mixed and homogenized to form LK-CG-TP microspheres. SEM images of the microspheres revealed a regular spherical shape and smooth surface with a mean diameter of 5−10 μM. TG and DSC analysis indicated that LK-CG-TP microspheres exhibited better thermal stability as compared to free TP. The release profile of LK-CG-TP in simulated gastric f... [more]

The use of microbial fuel cells (MFCs) is quickly spreading in the fields of bioenergy generation and wastewater treatment, as well as in the biosynthesis of valuable compounds for microbial electrolysis cells (MECs). MFCs and MECs have not been able to penetrate the market as economic feasibility is lost when their performances are boosted by nanomaterials. The nanoparticles used to realize or decorate the components (electrodes or the membrane) have expensive processing, purification, and raw resource costs. In recent decades, many studies have approached the problem of finding green synthesis routes and cheap sources for the most common nanoparticles employed in MFCs and MECs. These nanoparticles are essentially made of carbon, noble metals, and non-noble metals, together with a few other few doping elements. In this review, the most recent findings regarding the sustainable preparation of nanoparticles, in terms of syntheses and sources, are collected, commented, and proposed for a... [more]

This work studies how morphology (i.e., the shape of a structure) and topology (i.e., how different structures are connected) influence wall adsorption and capillary condensation under tight confinement. Numerical simulations based on classical density functional theory (cDFT) are run for a wide variety of geometries using both hard-sphere and Lennard-Jones fluids. These cDFT computations are compared to results obtained using the Minkowski functionals. It is found that the Minkowski functionals can provide a good description of the behavior of Lennard-Jones fluids down to small system sizes. In addition, through decomposition of the free energy, the Minkowski functionals provide a good framework to better understand what are the dominant contributions to the phase behavior of a system. Lastly, while studying the phase envelope shift as a function of the Minkowski functionals it is found that topology has a different effect depending on whether the phase transition under consideration... [more]

In this paper, we report the effect of adding Zr + V or Zr + V + Mn to TiFe alloy on microstructure and hydrogen storage properties. The addition of only V was not enough to produce a minimum amount of secondary phase and, therefore, the first hydrogenation at room temperature under a hydrogen pressure of 20 bars was impossible. When 2 wt.% Zr + 2 wt.% V or 2 wt.% Zr + 2 wt.% V + 2 wt.% Mn is added to TiFe, the alloy shows a finely distributed Ti2Fe-like secondary phase. These alloys presented a fast first hydrogenation and a high capacity. The rate-limiting step was found to be 3D growth, diffusion controlled with decreasing interface velocity. This is consistent with the hypothesis that the fast reaction is likely to be the presence of Ti2Fe-like secondary phases that act as a gateway for hydrogen.

Three-dimensional bioprinting can fabricate precisely controlled 3D tissue constructs. This process uses bioinks—specially tailored materials that support the survival of incorporated cells—to produce tissue constructs. The properties of bioinks, such as stiffness and porosity, should mimic those found in desired tissues to support specialized cell types. Previous studies by our group validated soft substrates for neuronal cultures using neural cells derived from human-induced pluripotent stem cells (hiPSCs). It is important to confirm that these bioprinted tissues possess mechanical properties similar to native neural tissues. Here, we assessed the physical and mechanical properties of bioprinted constructs generated from our novel microsphere containing bioink. We measured the elastic moduli of bioprinted constructs with and without microspheres using a modified Hertz model. The storage and loss modulus, viscosity, and shear rates were also measured. Physical properties such as micro... [more]

Rare earth elements (REEs) are becoming more and more significant as they play crucial roles in many advanced technologies. Therefore, the development of optimized processes for their recovery, whether from primary resources or from secondary sources, has become necessary, including recovery from mine tailings, recycling of end-of-life products and urban and industrial waste. Ionic solvents, including ionic liquids (ILs) and deep-eutectic solvents (DESs), have attracted much attention since they represent an alternative to conventional processes for metal recovery. These systems are used as reactive agents in leaching and extraction processes. The most significant studies reported in the last decade regarding the recovery of REEs are presented in this review.

In the present study, a phytochemical of Ficus sycomorus (Moraceae family) was screened, and the effect of this extract on rabbit performance indices, immunity, and carcass quality measures was determined. Ficus sycomorus samples were collected, air-dried, and extracted with 70% methanol to prepare a solution of 100 mg/mL concentration. The extract was subjected to high-resolution mass spectrometric measurements via ultra-high performance liquid chromatography-quadrupole time-of-flight-nanospray mass spectrometry (UPLC-QToF-MS) and 1H NMR analysis. Forty-eight male rabbits, one-month-old, belonging to the Blanc de Bouscat and New Zealand White breeds were selected and distributed equally in a 2 × 3 factorial trial. The rabbits within each breed received F. sycomorus extract at the dose of 0, 100, and 200 mg/kg for 60 days. Blood samples were collected and serum obtained for the detection of liver enzymes, serum lipids, and proteins. The results of UPLC-QToF-MS and molecular networking... [more]

This was early-stage, proof-of-concept research on the full utilization of biomass resources. The current study considered industrial hemp residue (IHR) and spent mushroom substrate (SMS) to demonstrate the initial upstream steps towards the total valorization of biomass. Accordingly, different pretreatment methods such as autohydrolysis, thermal hydrolysis, and thermochemical hydrolysis methods were employed against individual and various mix ratios of IHR and SMS. To this end, raw materials, hydrolysates, and residual solids were analyzed to gain some insights, identify gaps, and suggest future research directions in this area. Implementation of the full utilization of biomass resources is, in fact, not only a matter of transforming the resources into valuable products, but it is also a plausible waste management strategy in the quest towards the development of a circular bioeconomy and sustainable future.

Contamination of drinking water by arsenic and fluoride is a global problem, as more than 300 million people in more than 100 countries have been affected by their presence. These elements are considered the most serious contaminants in drinking water and their removal is a worldwide concern. Therefore, the evaluation of three alternative approaches—electrocoagulation, adsorption by biomaterials, and adsorption by metal oxide magnetic nanoparticles (MNPs)—was performed for arsenic and fluoride removal from groundwater. Arsenic removal from synthetic and groundwater (well water) was accomplished with the three processes; meanwhile, fluoride removal from groundwater was only reported by two methods. The results indicate that an electrocoagulation process is a good option for As (>97%) and F (>90%) removal in co-occurrence; however, the operational conditions for the removal of both pollutants must be driven by those used for fluoride removal. As (80−83%) and F (>90%) removal with the bio... [more]

Activated carbon (AC) is widely accepted for the removal of inorganic contaminants like mercury; however, the raw material used in the production of activated carbon is not always taken into consideration when evaluating its efficacy. Mercury oxidation and adsorption mechanisms governed by carbene sites are more likely to occur when graphitic-like activated carbons (such as those produced from high-ranking coals) are employed versus lignocellulosic-based ACs; this is likely due to the differences in carbon structures where lignocellulosic materials are less aromatic. In this research, the team studied bituminous coal-based ACs in comparison to coconut shell and wood-based (both less aromatic) ACs for elemental mercury removal. Nitric acid of 0.5 M, 1 M, and 5 M concentrations along with 10 M hydrogen peroxide were used to oxidize the surface of the ACs. Boehm titrations and FTIR analysis were used to quantify the addition of functional groups on the activated carbons. A trend was obser... [more]

The physicochemical properties of petroleum-derived jet fuels mainly depend on their chemical composition, which can vary from sample to sample as a result of the diversity of the crude diet processed by the refinery. Jet fuels are exposed to very low temperatures both at altitude and on the ground in places subject to extreme climates and must be able to maintain their fluidity at these low temperatures otherwise the flow of fuel to turbine engines will be reduced or even stopped. In this work, an experimental evaluation of the effect of chemical composition on low-temperature fluidity properties of jet fuels (freezing point, crystallization onset temperature and viscosity at −20 °C) was carried out. Initially, a methodology based on gas chromatography coupled to mass spectrometry (GC−MS) was adapted to determine the composition of 70 samples of Jet A1 and Jet A fuels. This methodology allowed quantifying the content, in weight percentage, of five main families of hydrocarbons: paraff... [more]

Liming is a common practice used to improve acidic soil properties, as is essential for agricultural quality. A long-term field experiment with one lime rate (6000 kg/ha of carbonate calcium equivalent) and three calcium-based liming amendments (gypsum, limestone and sugar foam) was maintained on a Typic Palexerult for 10 years in order to determine changes in soil acidity and to assess the effects on crop (rye) yields. The soil acidity conditions decreased with all the amendments tested, but the sugar foam and limestone was more effective than gypsum over a long-term period. No significant changes in organic soil matter levels between the treatments tested were found. Interestingly, an increase in the leaching of organic soil matter was observed in limed soils. Lime application significantly increased the total rye biomass compared to the control soils during the whole experiment (2002−2011). Yield trends observed in spike and stem biomass were similar to those reported for total rye... [more]

The fluid flow in the runner of a hydraulic turbine has serious uncertainties. The sealing failure of the magnetorheological (MR) fluid sealing device of the main shaft of the hydroturbine, caused by a sudden change in speed, has always been a difficult topic to research. This study first derives the MR fluid seal pressure and unbalanced curl equations of the hydroturbine main shaft, and then analyzes the seal pressure and friction heat under different rotational speed mutation conditions through experiments. After verification, the temperature field and magnetic field distribution of the MR fluid sealing device of the main shaft of the hydraulic turbine are obtained via numerical calculation. The results show that the external magnetic field affects the magnetic moment of the magnetic particles in the MR fluid, resulting in a significant change in frictional heat, thereby reducing the saturation of magnetic induction intensity of the MR fluid. This results in a decrease in the sealing... [more]

Phase change materials are commonly used for energy storage. Heat transfer enhancement and heat storage are the two main goals in this paper. A cylindrical pipe covered with phase change material is investigated numerically. Ideally, a high temperature liquid flows through the pipe, resulting in heat transferred to the phase change material. To enhance the heat transfer, various configurations involving the addition of a twisted tape inside of the pipe and the use of helical shape pipes were investigated. A straight pipe with no twisted tape insert was also analyzed and used as a benchmark case. All the configurations had constant properties such as material selection, overall size, pipe diameter and inlet Reynold’s number, so the performance could be compared under similar conditions. All initial configurations were simulated and the heat transfer rate, Nusselt number, friction factor and performance evaluation criterion (PEC) of the designs were determined. It was found that the heat... [more]

Forestry biomass is a by-product which commonly ends up being burnt for energy generation, despite comprising valuable bioactive compounds with valorisation potential. Leaves of Acacia dealbata were extracted for the first time by supercritical fluid extraction (SFE) using different conditions of pressure, temperature and cosolvents. Total extraction yield, individual triterpenoids extraction yields and concentrations were assessed and contrasted with Soxhlet extractions using solvents of distinct polarity. The extracts were characterized by gas chromatography coupled to mass spectrometry (GC-MS) and target triterpenoids were quantified. The total extraction yields ranged from 1.76 to 11.58 wt.% and the major compounds identified were fatty acids, polyols, and, from the triterpenoids family, lupenone, α-amyrin and β-amyrin. SFE was selective to lupenone, with higher individual yields (2139−3512 mg kgleaves−1) and concentrations (10.1−12.4 wt.%) in comparison to Soxhlet extractions... [more]

This work aims to develop a multihole atmospheric pressure plasma jet (APPJ) device to increase the plasma area and apply it to a continuous seed treatment system. Broccoli seed was used to study the effects of an atmospheric pressure plasma jet on seed germination and growth rate. An argon flow rate of 4.2 lpm, a plasma power of 412 W, and discharge frequency of 76 kHz were used for seed treatment. The contact angle decreased strongly with the increase in treatment time from 20 s to 80 s. The broccoli seed’s outer surface morphology seemed to have been slightly modified to a smoother surface by the plasma treatment during the treatment time of 80 s. However, the cross-sectional images resulted from Synchrotron radiation X-ray tomographic microscopy (SRXTM) confirmed no significant difference between seeds untreated and treated by plasma for 80 s. This result indicates that plasma does not affect the bulk characteristics of the seed but does provide delicate changes to the top thin lay... [more]

Seawater desalination provides a convenient method for the sustainable production of fresh water. However, the preparation of low-cost, high-efficiency solar absorbers remains a huge challenge. To this end, our research group designed and produced a cheap absorber—a membrane made of natural polymer chitin with black FeS and Fe3O4, respectively. Due to the hierarchical pore structure, excellent photothermal performance and good hydrophilicity of the film, their water evaporation rates reached 1.47 kg/m2/h and 1.55 kg/m2/h under one sunlight, respectively. Under about 10 suns, the highest desalination efficiency of FeS/chitin and Fe3O4/chitin are 90% and 74%, respectively, and their salinities are also in line with the World Health Organization drinking water standards. These results indicate the potential of chitin-based nanomaterials as high-efficiency solar absorbers to produce fresh water.

Presently, the realization of complex, unconventional designs using efficient modalities is possible due to an increasing interest in interdisciplinary approaches: materials science, mathematics, IT, architecture, etc. Computerized techniques, among which the algorithmic/generative design is the most advanced one, that are associated with the individualized production methods are used for finding solutions for modern spatial forms with an unconventional spatial geometric shape, which are generically called “free-forms”. This work presents the design, realization and testing of a thin-walled metallic structure proposed as a light structural unit. An integrated research approach was proposed that utilized an algorithmic/digital design applied to the curved-crease-folding method with the study (at different length scales) of the metallic material behaviour after folding. An original method was proposed for the digital design and simulations. The specific mechanical behaviour of the metall... [more]