Analytical Pyrolysis of Pinus radiata and Eucalyptus globulus: Effects of Microwave Pretreatment on Pyrolytic Vapours Composition.

Pinus radiata (PR) and Eucalyptus globulus (EG) are the most planted species in Chile. This research aims to evaluate the pyrolysis behaviour of PR and EG from the Bío Bío region in Chile. Biomass samples were subjected to microwave pretreatment considering power (259, 462, 595, and 700 W) and time (1, 2, 3, and 5 min). The maximum temperature reached was 147.69 °C for PR and 130.71 °C for EG in the 700 W-5 min condition, which caused the rearrangement of the cellulose crystalline chains through vibration and an increase in the internal energy of the biomass and the decomposition of lignin due to reaching its glass transition temperature. Thermogravimetric analysis revealed an activation energy (Ea) reduction from 201.71 to 174.91 kJ·mol-1 in PR and from 174.80 to 158.51 kJ·mol-1 in EG, compared to the untreated condition (WOT) for the 700 W-5 min condition, which indicates that microwave pretreatment improves the activity of the components and the decomposition of structural compounds for subsequent pyrolysis. Functional groups were identified by Fourier transform infrared spectroscopy (FTIR). A decrease in oxygenated compounds such as acids (from 21.97 to 17.34% w·w-1 and from 27.72 to 24.13% w·w-1) and phenols (from 34.41 to 31.95% w·w-1 and from 21.73 to 20.24% w·w-1) in PR and EG, respectively, was observed in comparison to the WOT for the 700 W-5 min condition, after analytical pyrolysis. Such results demonstrate the positive influence of the pretreatment on the reduction in oxygenated compounds obtained from biomass pyrolysis.

Optimised Sunflower Oil Content for Encapsulation by Vibrating Technology as a Rejuvenating Solution for Asphalt Self-Healing.

This study aimed to determine an optimal dosage of sunflower oil (i.e., Virgin Cooking Oil, VCO) as a rejuvenator for asphalt self-healing purposes, evaluating its effect on the chemical (carbonyl, and sulfoxide functional groups), physical (penetration, softening point, and viscosity), and rheological (dynamic shear modulus, and phase angle) properties of long-term aged (LTA) bitumen. Five concentrations of sunflower oil (VCO) were used: 1%, 2%, 3%, 4%, and 5% vol. of LTA bitumen. VCO was encapsulated in alginate biopolymer under vibrating jet technology using three biopolymer:oil (B:O) mass ratios: 1:1, 1:5, and 1:9. The physical, thermal, and mechanical properties of the capsules were studied, as well as their effect on the physical properties of dense asphalt mixtures. The main results showed that an optimal VCO content of 4% vol. restored the chemical, physical, and rheological properties of LTA bitumen to a short-term ageing (STA) level. VCO capsules with B:O ratios of 1:5 presented good thermal and mechanical stability, with high encapsulation efficiency. Depending on the B:O ratio, the VCO capsule dosage to rejuvenate LTA bitumen and asphalt mixtures varied between 5.03-15.3% wt. and 0.24-0.74% wt., respectively. Finally, the capsule morphology significantly influenced the bulk density of the asphalt mixtures.

Biopolymeric Capsules Containing Different Oils as Rejuvenating Agents for Asphalt Self-Healing: A Novel Multivariate Approach.

This study evaluated the effect of two encapsulation methods (i.e., dropping funnel and syringe pump), two concentrations of the alginate-based encapsulating material (2%, and 3%), and three oils as bitumen rejuvenators (virgin sunflower oil, waste cooking oil, and virgin engine oil) on the morphological, physical, chemical, thermal, and mechanical properties of encapsulated rejuvenators for asphalt self-healing purposes. A general factorial design 2 × 2 × 3 was proposed to design 12 different Ca-alginate capsules. Significant differences on the morphological, physical, and mechanical properties of the capsules were analysed by three-way ANOVA and Tukey HSD Post Hoc analyses. The effect of the type of oil on the self-healing capacity of cracked bitumen samples was also evaluated. The main results showed that the design parameters and their interactions significantly affected the morphological, physical, and mechanical properties of the capsules. Capsules synthesised via syringe pump method, with virgin cooking oil and 2% alginate was the most appropriate for asphalt self-healing purposes since its uniform morphology, encapsulation efficiency up to 80%, thermal degradation below 5% wt., and compressive strength above the reference asphalt compaction load of 10 N. Finally, the healing tests showed that virgin cooking oil can be potentially used as a rejuvenator to promote asphalt crack-healing.

Dataset on the reductive amination of phenolics with cyclohexylamine over Rh/C and Pd/C: Catalysts characterization and reaction performance.

Secondary amines play a very important role in today's chemical industry owing to their extensive applications in agricultural, pharmaceutical, textile, polymer and in personal care fields [1] Unfortunately, most of the amine synthesis processes at the industrial level are fossil-based and imply economic and environmental problems. However, the heterogeneously catalyzed reductive amination of lignin-derived phenolics has been recognized as an efficient and ecofriendly method for the synthesis of primary or higher order amines [2]. In this sense, metal-supported catalysts, specifically palladium, and rhodium-based materials, have demonstrated their effectivity to produce secondary amines [3,4]. Therefore, there is a crescent interest in evaluating their roles within the reaction mechanisms by testing different reaction conditions and phenolics sources. Nevertheless, there is a lack of experimental data allowing to establish a correlation between the nature of the metallic clusters, the operational parameters, and steric effects of alkyl-phenolics with the activity and selectivity to amines. Accordingly, this dataset includes reliable experimental measurements on the use of Pd/C and Rh/C as catalysts for the reductive amination of phenols (RAPhs). A complete set of characterization techniques was applied to inspect the structural and textural properties of these materials which will allow its further correlation with the reaction performance. Therefore, data regarding transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) with energy dispersive X-Ray analysis (EDX), X-ray diffraction (XRD) and specific surface area (BET) with pore size distribution (BJH) are provided here. Furtheremore, experimental data on the catalytic activity (in batch and/or dynamic modes) under different reaction conditions (phenol concentration, amine concentration, hydrogen pressure, temperature and alkyl-substituted phenols) are also included in the dataset. The data provided here could support the understanding on the role of active sites nature (Pd or Rh), the effect of operational parameters and the reactivity order for substituted phenols on the aforementioned reaction. Finally, we have included a sample datasheet which could aid the reader to perform preliminary kinetic analysis using the provided dataset.

Sirex noctilio infestation led to inevitable pine death despite activating pathways involved in tolerance.

Defense-related metabolome traits in pine species after infestation by Sirex noctilio are largely unknown, despite, in most cases, trees being overwhelmed. Using LC-MS-based untargeted metabolomics, we revealed the systemic metabolic changes induced by this insect in 14-year-old Pinus radiata trees, the most affected species worldwide. An immediate metabolome alteration was expressed in needles after infestation, including the up-regulation of flavonols, flavan-3-ols, oxyneolignans, auxins, proline, and tryptophan, among others. The flavan-3-ols (catechin and procyanidin B1) suggested a rapidly induced photoprotection mechanism aided by diverting proline as an alternative substrate for respiration to compensate for the progressive chlorosis that degrades photosystems. Meanwhile, glutathione, glutamate, and ascorbate levels significantly dropped in needles, which may indicate the critical oxidative stress that trees had to face since the onset of the infestation. They were not fully replenished after long-term infestation, and redox homeostasis was probably not achieved, compromising tree survival. Nevertheless, a huge auxins overexpression detected in needles throughout the infestation may reflect tolerance against the premature senescence caused by the woodwasp venom. In contrast, the metabolome of wood tissues remained initially unchanged, although it seems to collapse after three months. Overall, the metabolomics strategy adopted in this work evidenced its usefulness in uncovering the fundamental roles of plants' chemical defense that govern interactions with specific stressors.

Upcycling agro-industrial blueberry waste into platform chemicals and structured materials for application in marine environments.

Blueberry pruning waste (BPw), sourced as residues from agroforestry operations in Chile, was used to produce added-value products, including platform chemicals and materials. BPw fractionation was implemented using biobased solvents (γ-valerolactone, GVL) and pyrolysis (500 °C), yielding solid fractions that are rich in phenols and antioxidants. The liquid fraction was found to be enriched in sugars, acids, and amides. Alongside, filaments and 3D-printed meshes were produced via wet spinning and Direct-Ink-Writing (DIW), respectively. For the latter purpose, BPw was dissolved in an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([emim][OAc]), and regenerated into lignocellulose filaments with highly aligned nanofibrils (wide-angle X-ray scattering) that simultaneously showed extensibility (wet strain as high as 39%). BPw-derived lignocellulose filaments showed a tenacity (up to 2.3 cN dtex-1) that is comparable to that of rayon fibers and showed low light reflectance (R ES factor <3%). Meanwhile, DIW of the respective gels led to meshes with up to 60% wet stretchability. The LCF and meshes were demonstrated to have reliable performance in marine environments. As a demonstration, we show the prospects of replacing plastic cords and other materials used to restore coral reefs on the coast of Mexico.

Dataset from analytical pyrolysis assays for converting waste tires into valuable chemicals in the presence of noble-metal catalysts.

About 25.7 million tons of waste tires (WT) are discarded each year worldwide causing important environmental, and health problems. This waste is difficult to manage and dispose due to its huge rate of generation and its extremely slow biodegradation. Therefore, many efforts are being made to valorise WTs into a series of marketable products under a circular economy framework. In the attempt to convert WT into higher-value products, thermochemical decomposition by pyrolysis has emerged as a promising process [1]. The pyrolysis is a thermochemical transformation (under an oxygen-depleted atmosphere) of the tire´s polymeric constituents: natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) into three major fractions. These fractions are a gas (10-35%, TPG) which is usually used as a heat source (50 MJ kg-1), a solid consisting mainly of recovered carbon black (12-45%, rCB), and a liquid fraction (35-65%, TPO) containing a complex mixture of organic compounds. Among the high-value compounds that can be found in the TPO are D,L-limonene, isoprene, benzene, toluene, mixed-xylene, ethylbenzene, styrene, p-cymene, and some polycyclic aromatic hydrocarbons. This mixture is commonly used as a diesel substitute and owing to its complex composition it rarely is seen as a source for more valuable products. To overcome such a complexity, and selectively produce specific chemical identities, different types of catalysts have been used [2,3]. Herein, we provide a dataset from a systematic study about catalytic pyrolysis of WT for selectively producing benzene, toluene, and xylenes (BTX) and p-cymene on noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti). The comprehensive analysis of this data was recently published, thus, the analytical techniques, experimental conditions and dataset are given in the present paper as a complement to that publication [1]. The reaction was evaluated in an analytical pyrolysis unit consisting in a micropyrolizer coupled to a mass spectrometer (Py-GC/MS) operating at temperatures between 400 and 450 °C in a fast pyrolysis regime (12 s). The effectivity of catalysts was measured in terms of selectivity to monoaromatics as BTX and p-cymene, under non-catalytic and for catalytic pyrolysis conditions. Moreover, the reaction was conducted on individual rubbers (Polyisoprene, Polybutadiene, and Styrene-Butadiene) and DL-limonene, to get deep insights into the transformation behaviour and reaction pathways. Therefore, the reader will find a data-in-brief paper containing some characterizations of the WTs used for the investigation, along with a complete dataset of Py-GC/MS results. Finally, the original files for the interpretation of the MS results are also provided, so that the reader can easily use this information to further expand the study to their own interest (industrial or scientific).

Experimental protocol for the study of One-pot amination of Cyclohexanone-to-secondary amines over Carbon-supported Pd.

The validation of protocols for carrying out the experimental analysis of amination reactions is of paramount importance to enhance the scientific knowledge and reproducibility of results. Accordingly, in the present paper, a protocol has been proposed for the study of the amination of cyclohexanone-to-secondary amines (Diphenylamine and N-Cyclohexylaniline) over heterogeneous catalysts. The results of activity and selectivity, and the elucidation of a plausible reaction pathway were described in a parent paper. Therefore, the purpose of this document is to inform about the details of the experimental setups, the methods, and the analytical techniques to identify and quantify the reaction products. Finally, some practical and safety considerations are also included.•One-pot catalytic amination of cyclohexanone with aniline was performed efficiently in liquid phase on Pd/C.•Stirring, He atmosphere and temperature control were critical to achieve reproducible activity results.•Ultra-High Performance Liquid Chromatography allows identifying products and reaction intermediates, while nonane performed well as internal standard for GC-FID quantification.

Microencapsulated Bio-Based Rejuvenators for the Self-Healing of Bituminous Materials.

Asphalt self-healing by encapsulated rejuvenating agents is considered a revolutionary technology for the autonomic crack-healing of aged asphalt pavements. This paper aims to explore the use of Bio-Oil (BO) obtained from liquefied agricultural biomass waste as a bio-based encapsulated rejuvenating agent for self-healing of bituminous materials. Novel BO capsules were synthesized using two simple dripping methods through dropping funnel and syringe pump devices, where the BO agent was microencapsulated by external ionic gelation in a biopolymer matrix of sodium alginate. Size, surface aspect, and elemental composition of the BO capsules were characterized by optical and scanning electron microscopy and energy-dispersive X-ray spectroscopy. Thermal stability and chemical properties of BO capsules and their components were assessed through thermogravimetric analysis (TGA-DTG) and Fourier-Transform Infrared spectroscopy (FTIR-ATR). The mechanical behavior of the capsules was evaluated by compressive and low-load micro-indentation tests. The self-healing efficiency over time of BO as a rejuvenating agent in cracked bitumen samples was quantified by fluorescence microscopy. Main results showed that the BO capsules presented an adequate morphology for the asphalt self-healing application, with good thermal stability and physical-chemical properties. It was also proven that the BO can diffuse in the bitumen reducing the viscosity and consequently self-healing the open microcracks.

Coaxial Spinning of All-Cellulose Systems for Enhanced Toughness: Filaments of Oxidized Nanofibrils Sheathed in Cellulose II Regenerated from a Protic Ionic Liquid.

Hydrogels of TEMPO-oxidized nanocellulose were stabilized for dry-jet wet spinning using a shell of cellulose dissolved in 1,5-diazabicyclo[4.3.0]non-5-enium propionate ([DBNH][CO2Et]), a protic ionic liquid (PIL). Coagulation in an acidic water bath resulted in continuous core-shell filaments (CSFs) that were tough and flexible with an average dry (and wet) toughness of ∼11 (2) MJ·m-3 and elongation of ∼9 (14) %. The CSF morphology, chemical composition, thermal stability, crystallinity, and bacterial activity were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, pyrolysis gas chromatography-mass spectrometry, wide-angle X-ray scattering, and bacterial cell culturing, respectively. The coaxial wet spinning yields PIL-free systems carrying on the surface the cellulose II polymorph, which not only enhances the toughness of the filaments but facilities their functionalization.

Waste tires pyrolysis kinetics and reaction mechanisms explained by TGA and Py-GC/MS under kinetically-controlled regime.

The fast pyrolysis of waste tires (WTs) is studied by quasi-isothermal thermogravimetric (TGA) analysis, kinetic modelling and an analytical pyrolyzer coupled with gas chromatography/mass spectrometry (Py-GC/MS). The TGA demonstrated that the WTs pyrolysis is ruled by devolatilization/condensation and depropagation reactions, up to 482 °C. At higher temperatures, the cyclization and aromatization of primary products take place to form mostly monoaromatics. Py-GC/MS experiments were performed under kinetic regime according to the thermal map established by the ratio between Biot́s (31.25) and Py-numbers (7.7⋅106). Limonene (51%) and isoprene (20.5%) were the major compounds detected at temperatures below 435 °C, while above 600 °C limonene was converted to mono-aromatics (SBTX = 28.7%). The approach to equilibrium of Diels-Alder reaction demonstrated that there is an equilibrium-ruled behavior between isoprene and limonene, particularly at T > 600 °C. The Ea values calculated by the Starinks model ranged from 101.5 to 176.7 kJ/mol, while for model-based kinetics it was 152.7 kJ/kmol. The integration of TGA, kinetic modelling and Py-GC/MS provided insights into pyrolysis reaction mechanism.

Steam torrefaction of Eucalyptus globulus for producing black pellets: A pilot-scale experience.

Steam torrefaction of Eucalyptus globulus was performed at temperatures between 245°C and 265°C in a 100kg/h pilot plant. Torrefied biomass was then pelletized in a 300kg/h unit and the pellets were subject to durability, density and combustion tests. The structural changes measured with FTIR were studied along with the combustion behavior of the materials. Compositional analysis showed that increasing the torrefaction temperature reduced both hemicellulose fraction and overall mass yield (MY). Furthermore, there was a linear relationship between the energy yield (EY) and mass yield (EY=[1.04-0.9(1-MY)]) for these samples. The ignition and comprehensive indexes confirmed that the stability of the torrefied biomass in a combustion environment was higher than for untreated biomass. Finally, pellets showed high durability (98%), and had an energy density (13-14GJ/m3), which is comparable to low-rank coals.

An investigation on the modelling of kinetics of thermal decomposition of hazardous mercury wastes.

The kinetics of mercury removal from solid wastes generated by chlor-alkali plants were studied. The reaction order and model-free method with an isoconversional approach were used to estimate the kinetic parameters and reaction mechanism that apply to the thermal decomposition of hazardous mercury wastes. As a first approach to the understanding of thermal decomposition for this type of systems (poly-disperse and multi-component), a novel scheme of six reactions was proposed to represent the behaviour of mercury compounds in the solid matrix during the treatment. An integration-optimization algorithm was used in the screening of nine mechanistic models to develop kinetic expressions that best describe the process. The kinetic parameters were calculated by fitting each of these models to the experimental data. It was demonstrated that the D1-diffusion mechanism appeared to govern the process at 250°C and high residence times, whereas at 450°C a combination of the diffusion mechanism (D1) and the third order reaction mechanism (F3) fitted the kinetics of the conversions. The developed models can be applied in engineering calculations to dimension the installations and determine the optimal conditions to treat a mercury containing sludge.