The allocation of environmental burdens for products in recycling systems remains a significant challenge within the life cycle assessment (LCA) field with a lack of consensus on which methodology should be applied. The present study compared fourteen allocation methods in a corrugated containerboard made of recycled and virgin fibers base case scenario with the aim to showcase the implications and outcomes when applying each methodology. The total CO2 eq. emissions per fifty recycling cycles were calculated by each method, showing variations ranging from 6.3 % to 17.9 % compared to the base case scenario. However, this range decreased to between 0 % and 12 % when acknowledging fiber losses in the system. Thus, this work highlights the importance of including fiber losses when applying the allocation methodologies. The cut-off method proved to be more accurate for allocating emissions in the system studied due to its simplicity of application and lower deviations from the baseline.

This study explored the extraction and microencapsulation of essential oil from Pistacia terebinthus cambium layer gum (PTG-EO) using response surface methodology (RSM) to optimize extraction efficiency. Significant factors such as extraction method, time, and power were optimized for conventional extraction (CE) and microwave-assisted extraction (MAE), yielding 24.48 and 21.97

Producing a valuable nanofibers can occurs by electrospinning, as it consider one of advanced spinning techniques that can obtain functionalized fibers for smart application. The current work demonstrated for new exploration of electrospinning process of cellulose acetate (CA) from trisolvent mixtures. 5% water added to stable CA Electrospinning solution that contains DMAc/AC (1:2). Five different speeds 6, 12, 22, 32 and 40 ml/hr were applied to CA solution. The reflectance of water addition on electrospun fiber properties on fiber diameter and homogeneity was visualized using SEM and Mechanical properties also Contact angles of the preformed nanofibers were characterized. In addition to air permeability test were also evaluated. The obtained fibers showed different morphology against spinning rate. Surface behavior of spun fibers is nearly similar to pristine cellulose acetate (CA) fiber spanned from di-solvent. Spinning rate affects positively on tensile properties and negatively on elongation modulus. The spinning rates indirectly proportional to fiber diameter that reflected on the air permeability. Spinning rate 22ml/hr showed the optimum velocity for spinning from tri-solvent CA solution. Conclusionally, the obtained results open the door for high speed electrospinning process saving time and cost achieving the research target.

The overwhelming demand for lithium-ion batteries necessitates a sustainable and environment-friendly production of graphite anode materials. Catalytic graphitization of pyrolysis oil is promising for mass-scale production of biographite.

Biomass, as a raw material, has been identified as a crucial component of decarbonization strategies to mitigate climate change. Decisions on which biomass should be targeted for different purposes are dependent on variables such as availability, chemical composition, and sustainability. Consumer perception often positions non-wood sources, such as bamboo, as environmentally preferable feedstocks for fiber-based product production. Yet, this perceived environmental benefit lacks robust scientific substantiation and standardized methodologies. This study addresses this gap by conducting a cradle-to-gate life cycle assessment (LCA) of twelve biomass production systems encompassing tree plantations, dedicated crops, and agricultural residues for energy and bioproducts manufacture. The evaluated feedstocks include southern softwood, wheat straw, rice straw, rice husk, hemp hurd, sugarcane bagasse, switchgrass, biomass sorghum (United States), eucalyptus (Brazil), bamboo (China), and northern softwood (Canada). Incorporating a critical yet often overlooked factor, this LCA integrates the potential soil organic carbon sequestration (SOC) via below-ground biomass for each biomass type. This consideration significantly alters the estimated carbon intensity per ton of feedstock, potentially reshaping sustainability perceptions as certain systems emerge as carbon sinks. From a cradle-to-farm gate perspective, the assessed global warming potential for biomass production spans 12-245 kg CO2eq per oven -dry ton (ODt), factoring only anthropogenic emissions. However, when accounting for SOC sequestration, the range shifts to -170 to 228 kg CO2eq per ODt, highlighting the potential role of biomass to act as carbon sink systems. By illuminating the dynamic influence of SOC sequestration, this study contributes to a more comprehensive understanding of biomass-related carbon emissions, shedding light on pathways to mitigate environmental impact.

The present work deals with the chemical properties of vegetable oils commonly used for deep-frying, for example, sunflower, corn, cotton, canola, and olive oils. Ten deep-frying cycles were carried out for 20 min each. Oil degradation was measured by peroxide values (PVs) and was highly correlated with the presence of conjugated-diene and conjugated-triene structures. Frying cycles caused two alternative reactions, which both impacted the PV. In one reaction, there was an increase in PV with the oxidation of the unsaturated bonds, and in the second stage, there was a decrease in the cleavage of the double-bond oxide. Additionally, the point of returns (PRs) and activation energy (Ea) were determined for the two stages. The PRs were eight cycles for olive and corn, five cycles for canola, four cycles for sunflower, and three cycles for cotton oil. In terms of ER, the olive and cotton oils had the highest ER and were most resistant to decomposition, and the associated activation energy formation of peroxide decomposition products. The corn oil was the least resistant to decomposition. In addition, this work demonstrated a novel analytical technique that showed the correlation between the total value of conjugated diene-triene structures and PV, using a titration method. The correlation was high confidence for the regression, recovery, and U-95. This significant correlation is useful for measuring the PV of oils subjected to other processes.

The production of cellulose diacetate (CDA) faces an ongoing challenge with the formation of insoluble colloidal materials, referred to as insoluble gel particles (IGP). CDA is typically dissolved in solvents like acetone for processing into commercial products. However, IGP presents challenges in the production of commercial CDA-based products, potentially impacting both intermediate processing and quality of the final products. IGP formation is connected to factors such as incomplete acetylation and the presence of hemicellulose acetates, but its root cause is still debated. This study primarily investigates the impact of hemicelluloses on IGP formation during CDA production. To study IGP formation, we proposed scenarios using xylan acetate (XA) as a model impurity. The results show that the precipitation process employed for CDA recovery plays a crucial role in IGP formation, with acetone-soluble CDA also contributing to IGP formation during precipitation. Additionally, the persistence of IGP is influenced by the behavior of XA in redissolution solvents.

Due to the inherent advantages of cellulose derivatives, there has been a dedicated focus in research to employ them as alternatives to synthetic materials. In this study, we investigated the potential of cellulose acetate sulfate (CAS) for the film fabrication, exploring how the properties of CAS films vary in relation to the number of sulfate groups (DSsulfate). CAS films with different DSsulfate (0.4, 0.7, and 1.0) were prepared using solvent casting. Despite variations in DSsulfate, all CAS produced transparent and self-supporting films. Nonetheless, the characteristics of CAS films were found to be significantly influenced by their DSsulfate. Owing to the size of sulfate groups, the substitution of these groups induces alterations in the polymer networks present within CAS films. These alterations, combined with the hydrophilic nature of sulfate groups, give rise to distinct variations in the characteristics of films associated with DSsulfate. CAS films with the lowest DSsulfate (0.4) demonstrated superior mechanical properties with an elastic modulus of 2131.6 MPa and tensile strength of 36.7 MPa. Conversely, higher DSsulfate correlated with increased wettability and water vapor permeability (WVP). CAS films with the highest DSsulfate exhibited maximum wettability (43.2°) and WVP (2.58 × 10–10 g·s−1·m−1·Pa−1). These findings, given the limited research on CAS characteristics, hold the potential to expand horizons in the selection of eco-friendly materials based on cellulose derivatives.

Hydrogels, typically favored for 3D printing due to their viscoelasticity, are now trending toward ecofriendly alternatives amid growing environmental concerns. In this study, we crafted cellulose-based hydrogels, specifically employing cellulose acetate sulfate (CAS). By keeping the acetyl group substitution degree (DSacetyl = 1.8) and CAS molecular weight constant, we varied rheological properties by adjusting sulfate group substitution (DSsulfate = 0.4, 0.7, and 1.0) and CAS concentration (2-5 wt %). Rheological characterizations, including shear-thinning, yield stress, and thixotropy, were performed to identify optimal conditions for formulating CAS hydrogel ink in direct ink writing for 3D printing under selected experimental conditions. Based on rheological findings, CAS hydrogels with DSsulfate 0.7 and concentration of 4 wt % was used for 3D printing, with subsequent evaluation of printing metrics. Additionally, the effect of ionic cross-linking using Ca2+ ions on the structural integrity of 3D-printed structures was evaluated, demonstrating effective preservation through reinforced polymer networks. The shrinking and swelling behaviors of the 3D-printed structures were also significantly affected by this ionic cross-linking. Building on these findings, this work could broaden the range of cellulose derivatives available for the preparation of cellulose-based hydrogels for 3D printing.

Evolution by natural selection has built a vast array of highly efficient lifelong learningLifelong learning organisms, as evidenced by the spectacular diversityDiversity of species that rapidly adapt to environmental change and acquire new problem-solving skills through experience. Reinforcement Learning (RL) is a machine learning problem in which an agent must learn how to map situations to actions in an unknown world in order to maximise the sum of future rewards. There are no labelled examples of situation $$\rightarrow $$ action mappingsMapping to learn from and we assume that no model of environment dynamics is available. As such, learning requires active trial-and-error interaction with the world. Evolutionary Reinforcement Learning (EvoRL), the application of evolutionary computation in RL, models this search process at multiple time scales: individual learning during the lifetime of an agent (i.e., operant conditioning) and population-wide learning through natural selection. Both modes of adaptation are wildly creative and fundamental to natural systems. This chapter discusses how EvoRL addresses some critical challenges in RL including the computational costComputational cost of extended interactions, the temporal credit assignmentCredit assignment problem, partial-observability of state, nonstationary and multi-task environments, transfer learningTransfer learning, and hierarchical problem decomposition. In each case, the unique potential of EvoRL is highlighted in parallel with open challenges and research opportunities.

Under the controversial concern of using virgin fibers in hygiene tissue products, mostly Bleached Eucalyptus Kraft (BEK) and Northern Bleached Softwood Kraft (NBSK), consumers are responding by purchasing self-labeled sustainable products. As of today, there are no established sustainability reported results to inform consumers about the carbon footprint of hygiene tissue. To fill this gap, this study used Life Cycle Assessment to evaluate the environmental impacts across the supply chain (cradle to gate) to produce Premium and Ultra grades of bath tissue, including the production of feedstock, pulp production, and tissue production stages, with focus on Global Warming Potential (GWP). The results showed that one air-dried metric ton (ADmt) of BEK pulp had an associated GWP of 388 kgCO2eq, whereas one ADmt of NBSK pulp presented values ranging between 448 and 596 kgCO2eq, depending on the emissions allocation methodology used. It was estimated that the GWP of one finished metric ton of tissue weighted average could range from 1,392 to 3,075 kgCO2eq depending on mill location, electricity source, and machine technology. These results provide an understanding of the factors affecting the environmental impact of hygiene tissue products, which could guide manufacturers and consumers on decisions that impact their carbon footprint.

The need to decarbonize and reduce the impact of human activities is opening the window for new bioproducts. The industry of bioplastics has grown exponentially in the past years, and its production is expected to triple by 2026. Different bioplastics are currently produced, but bio-polyethylene constitute an interesting opportunity since its fossil counterpart is one of the most used materials worldwide, and its precursor, ethylene, is one of the highest contributors to GHG emissions in the chemical industry. The true environmental impact of this bio-based plastic remains under controversial discussions due to a wide distribution of environmental indicators values found in the literature for this material. We aim to thoroughly evaluate the environmental impact of bio-polyethylene made from sugarcane across the different production stages through a life cycle analysis. Our goal is also to assess unintended consequences (consequential effects) of producing it. It was determined that land-use change represents the main aspect affecting the environmental sustainability of bio-polyethylene. From an attributional point of view, this bioplastic could present lower carbon footprints than fossil polyethylene if no deforestation occurs. From a consequential standpoint, indirect deforestation as a response to producing more bioplastic could negatively impact the environmental profile of this material. Policies restricting deforestation are required to ensure that bio-polyethylene can constitute an alternative to reduce the carbon footprint of products in both scenarios. We expect this work to provide a robust evaluation to understand the environmental impact of bio-polyethylene, which will help the industry understand the place of this bio-based plastic and in-crease the offering of more sustainable products.

Automated machine learning (AutoML) greatly eases human efforts in architecture engineering. However, mainstream AutoML methods like neural architecture search (NAS) are customized for well-designed search spaces wherein promising architectures are densely distributed. In contrast, AutoML-Zero builds machine-learning algorithms using basic primitives and can explore novel architectures beyond human knowledge. AutoML-Zero shows the potential to deploy machine learning systems by not taking advantage of either feature engineering or architectural engineering. In its current form, it only optimizes a single objective like accuracy and has no mechanism to ensure that the constraints of real-world applications are satisfied. We propose a multi-objective variant of AutoML-Zero called MOAZ, that distributes solutions on a Pareto front by trading off accuracy against the computational complexity of the machine learning algorithm. In addition to generating different Pareto-optimal solutions, MOAZ can effectively explore the sparse search space to improve search efficiency. Experimental results on linear regression tasks show MOAZ reduces the median complexity by 87.4% compared to AutoML-Zero while accelerating the median target performance achievement speed by 82%. In addition, our preliminary results on non-linear regression tasks show the potential for further improvements in search accuracy and for reducing the need for human intervention in AutoML.

The growing concern for the environment has resulted in renewed interest in bio-based resources. This study aims to produce a hydrogel adsorbent from cellulose and examine its adsorption performance. In pursuit of this goal, we report a simple one-pot synthesis of cellulose acetate sulfate (CAS), followed by the formation of CAS hydrogels and their subsequent adsorption performances. The CAS includes both hydrophilic and hydrophobic functional groups, enable the formation of a single-component hydrogel through intermolecular interactions in deionized water. The thermal reversibility of CAS hydrogels makes them easily processable into various shapes. The durability of the CAS hydrogel adsorbents can be improved by introducing divalent cations (e.g., Ca2+), which create ionically crosslinked hydrogels. The ionically a crosslinked CAS hydrogel adsorbent exhibits a maximum adsorption capacity of 245 mg/g for methylene blue (MB) at 23 °C and a pH of 7. The adsorption behavior of MB on the CAS hydrogel follows both the pseudo-second-order model and the Langmuir adsorption isotherm model. Furthermore, the CAS hydrogel adsorbent maintains a 70 % removal ratio after five cycles. The simplicity of synthesis and hydrogel formation opens up new possibilities for producing and utilizing cellulose-based hydrogels as adsorbents for aqueous contaminants.

A new method for producing green needle coke (GNC) is developed by replacing the "heavy fraction" of petroleum pitch delayed coking with fast pyrolysis biocrude. A series of alternative biocrude distillation, carbonization, and calcination conditions were investigated to determine the influence of these processing parameters onto the crystalline structure of the resulting graphitized material. For the first time, the addition of biochar fines was found to serve as a "physical template" to increase the graphitic nature of the final product. During the initial biocrude carbonization (350-450 degrees C), volatile compounds are released, and aromatics in pyrolysis biocrude experience condensation, resulting in GNC solids with carbon contents above 95 wt % and some early lamellar structure. In the second stage of the thermal process (25-1500 degrees C), there are additional thermal decomposition reactions with an increase in the aromatic nature of the graphitized solid. It was found that systematic addition of biochar fines induces a nucleating effect during the GNC development. Thermogravimetric analysis suggests that biochar fines promote polycondensation reactions by modifying the biopitch structure and molecular weight, while elemental analysis (CHN) shows a reduction in both H/C and O/C ratios which are consistent with the increase in aromaticity and removal of oxygenated compounds as thermal treatment evolves. The effects of different bio-based pitch materials (after distillation) and GNC intermediates were evaluated by pyrolysis-gas chromatography mass spectrometry and Fourier transform infrared, displaying slight changes on product yields and quality. X-ray diffraction patterns taken after graphitization evidence an increase in the graphitic order with the addition of biochar fines. Transmittance electron microscopy depicts an improvement on graphitic morphology as biochar fine content increases. The use of biochar fines showed a significant increase in graphitic ordering at addition levels above 0.01 wt %. These results show that thermally treated biocrude/biochar fine systems can produce graphitic structures (hard carbon-like) that might be suitable for the manufacture of sodium-ion batteries.

In this study, the production and characterization of activated carbons (ACs) from agricultural and forest residue using physical activation are discussed. Biomass-based biochars produced during fast pyrolysis process is introduced as alternative precursors to produce AC and the integrated process for the co-production of porous adsorbent materials from biochar via the fast pyrolysis process is suggested. Moderate surface areas and good adsorption capacities were obtained from switchgrass (SWG) and pine tops (PT) based AC. The surface areas were 959 and 714 m2/g for SWG- and PT-based AC, respectively. The adsorption capacities using toluene as pollutant for two model systems of 180 and 300 ppm were measured and ranged between 441-711 and 432-716 mg/g for SWG-based and PT-based AC, respectively. The nitrogen adsorptive behavior, Lagergren pseudo-second-order kinetic (PSOK) model and kinetics isotherms studies describe a heterogeneous porous system, including a mesoporous fraction with the existence of a multilayer adsorption performance. The presence of micropores and mesopores in SWG- and PT-based AC suggests potential commercial applications for using pyrolytic biochars for AC production.

In this study, production and characterization of active carbons (AC) derived from pyrolytic biochar from agricultural and forest residues using physical activation is detailed. The co-production of activated carbons from biochar integration into fast pyrolysis process is suggested as alternative precursors, leading to further engineering process improvements. Moderate surface areas and good adsorption capacities were obtained from switchgrass (SWG) and Pine tops (PT) biochars. The surface areas were 959 and 714 m 2 /g for SWG and PT, respectively. The adsorptive capacities were measured using toluene as model system and ranged between 441-711 and 432 -716 mg/gr for SWG and PT, respectively. The adsorption capacity was measured using a batch-wise adsorption chamber, following the Langergren pseudo-second order kinetic model (PSOK). Both nitrogen adsorption behavior and PSOK implied a highly porous system, including a mesoporous fraction. Micropores and mesopores presence suggests potential commercial applications for using pyrolytic biochars for AC production.

The need to tackle the current environmental impact of plastics is driving the development of new bio-based materials. Although these bioplastics offer carbon footprint reductions, their role in a more sustainable econ-omy is still unclear. Herein, a systematic review was performed to understand the impact of producing bio-plastics. This information was used to perform a life cycle assessment considering different end-of-life scenarios. Then a Smart Use of Materials based on the assumption of only using certain materials in targeted applications was proposed. It was found that the dedicated use of bio-polyethylene terephthalate for packaging and polylactic acid for textiles can offer a carbon footprint reduction of up to 67% and 80% respectively. Therefore, we present a major opportunity to decarbonize our society using current technologies and supply chains. This concept contributes to building a society that understands the place of bio-based materials and addresses pollution from a material selection perspective.

Technical lignins are generated as byproducts from the wood pulping industry. Although their estimated annual production amounts to approximately 70 million tons, their exploitation as valueadded products remains insignificant. Yet, the diversity in the molecular structure and surface chemistry of technical lignins and their intrinsic role as mechanical support of plants may be an asset to consider in the engineering of plant-inspired materials such as biofoams. Valorization of lignins into solid foams, however, rarely accounts for more than 45-50 wt % of lignins because of their brittle nature. Herein, we report a strategy to develop fully biodegradable lignin-based foams of high stiffness, strength, and toughness that are comparable to, or in some cases exceed, the performance of petroleum-derived foams. A dual-templating approach using ice and cellulose nanofibrils (CNFs) as templates was selected to control the porous architecture of the foams made by the assembly of lignin and cellulose in the cell walls. Foams with varying lignin-to-CNF weight ratios showed enhanced structural and mechanical integrity compared with neat lignin and CNF foams. For 80-90 wt % of lignin, a significant increase (+50%) in the foams' compressive performance was observed. Varying the degree of sulfonation of lignin and in turn its chemical interaction with cellulose enabled the generation of biodegradable composite foams with tunable compressive strength. The greater the colloidal stability of the lignin-CNF suspension, the higher the foams' compressive performance. This study thus discusses an engineering approach for the valorization of technical lignins into sustainable foams that have potential as packaging materials and sandwich panels, in which high stiffness, strength, and toughness per unit weight are required.