The scientific community is focusing on developing supercapacitors with high capacitance, power and energy from waste-derived electrode materials and low-toxic aqueous electrolytes that can provide ...an advance in energy storage as well as the care for the environment. This work presents the development of a symmetric solid-state supercapacitor with activated carbon from olive pruning. Activated carbons were synthesized by chemical and physical methods varying their conditions. The physicochemical characterization determined that chemically activated carbons provided the highest surface areas, greater than 2000 m2 g−1. The electrochemical performance of chemically activated carbons was superior to physically activated carbons due to the high surface area and the developed pore structure that promote capacitances of up to 410 F g−1. Three symmetric solid-state supercapacitors with chemically activated carbon as electrode material and PVA-KOH hydrogel as electrolyte were assembled, and windows potential and drying time of the membrane were evaluated. An excellent performance supercapacitor was developed with electrode materials from olive pruning waste, which presented a capacitance of 1.15 F at 5 mA, a voltage of 1.2 V and equivalent series resistance of 1.42 Ω. These results present a promising way to develop competitive energy storage devices using agro-industrial waste to produce electrode materials.
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•Olive tree pruning residue can be utilized for producing activated bio-carbons.•Chemical activation provides a hierarchical porous structure and a high specific area.•Activated bio-carbons can be used as electrode materials for supercapacitors.•Solid-state symmetric supercapacitors can be built from agro-industrial wastes.•Waste recovery is a low-cost and eco-friendly way to get energy storage materials.
Dear Olive Tree Arlander, Annette
Journal of Embodied Research,
10/2021, Letnik:
4, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This video article consists of the video Dear Olive Tree (19 min) recorded in La Foia d'Ulldecona on 19 December 2019 with olive tree no. 968, three letters written to the tree and some reflections. ...Keywords: olive tree, letter, performing writing
World olive production is based on the cultivation of different varieties that respond differently to abiotic factors. Climate change may affect the area of land suitable for olive cultivation and ...change production levels, thus causing serious damage to this economically-relevant and highly-productive olive grove agroecosystem. In Mediterranean regions such as Andalusia, one of the main areas of olive production, the effect of climate change seems threatening. Thus, our main aims are: (1) to examine the abiotic factors that characterise the current cultivated locations and predict the current and potential distribution of these locations; (2) to evaluate the effect of climate change (based on regional scenarios) on the future environmental suitability of each olive variety; and (3) to analyse the expected alteration in the annual olive production. We used the seven most-productive olive varieties in Andalusia and the wild olive species to develop Species Distribution Models (SDMs), coupled with soil properties, geomorphology, water balance and (bio-)climatic predictors at a fine scale. We also derived future climate projections to assess the effect of climate change on the environmental suitability and productivity of each olive variety. We found that soil pH was the most-important factor for most distribution models, while (bio-)climatic predictors - such as continentality index, summer and autumn precipitation and winter temperature - provided important contributions. In general, projections based on regional climate change scenarios point to a decrease in the area suitable for olive crops in Andalusia, due to an increase in evapotranspiration and a decrease in precipitation. These changes in suitable area are also projected to decrease olive production for almost all the olive-growing provinces investigated. Our findings may anticipate the effects of climate change on olive crops and provide early estimates of fruit production, at local and regional scales, as well as forming the basis of adaptation strategies.
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•Climate change will significantly reduce the suitable area of main olive varieties.•Drier and warmer conditions in summer and autumn are the main drivers of change.•SDM-based environmentally-suitable area can predict olive production and its trend.•Framework potentially applicable to other olive grove areas and cultivation systems.
In this study the optimization of the hydrothermal carbonization process for the conversion of olive tree pruning into biofuel is presented. To this end, a combined experimental-economic assessment ...is performed. Experimental data obtained at laboratory scale were used to estimate the economic performance of a hypothetical industrial scale plant. To evaluate the viability of the project, three different plant sizes according to their capacity were selected (1250–625–312.5 kg/h). The discounted cash flow method was applied for the profitability analysis. Different scenarios were analyzed considering the reduction of associate costs or the improvement of the revenues compared to the baseline case. Results indicate that with the sizes studied, none of the alternatives are profitable. Despite that, the larger capacity shows the best outcomes. In this case, minimum selling price of 0.39 €/kg for hydrochar is required to reach profitability. Lower plant sizes would require higher selling prices (i.e., 0.46 €/kg for 625 kg/h capacity and 0.59 €/kg for 312.5 kg/h capacity). Similarly, a reduction of 33% in the electrical energy consumption can make the plan be profitable for the larger capacity. Likewise, a reduction until 0.053 €/kWh in the electricity price must be reached for achieving profitability. Thus, importance of government incentives is revealed in this work given that the reduction of costs along with the improvement in the revenues for the selling of the product can make the project economically viable. Other parameters like the number of workers are also interesting to consider as for example the reduction by two units improves the NPV value in almost 600 k€ for all the plant sizes.
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•Combining experimental-economic assessment of hydrothermal carbonization is performed•The high energy needs make the process unprofitable under the estimated circumstances•Breakeven prices for hydrochar are not competitive with the current ones for coal•Government subsidies are essential to boost the economic feasibility of the project
In order to improve bioethanol production from hydrolysates from olive tree pruning residues the present study assessed a detoxification method using the same waste material. The objective was to ...develop optimal removal without diminishing fermentable sugars. A statistical optimisation study was performed for the production of activated carbons using the same olive tree pruning residue as raw material. The effect of the impregnation ratio, activation temperature and the time needed for maximum removal of the phenolic compounds was assayed. The conditions for maximum adsorption were as follows: 799.18 °C, IR 4.88 and 101.38 min of activation, removing 55%, 64% and 41% of total phenolic compounds, HMF and furfural, respectively. The activated carbon obtained under optimum conditions (Aop) was submitted to adsorption kinetics and equilibrium assays. Experimental kinetic data were well represented by a pseudo-first order kinetic and intraparticle diffusion model, which helped explain the adsorption mechanism. Experimental isotherms were analysed with Langmuir, Freundlich and Temkin models, and Langmuir best fitted the experimental data. Hydrolysate from olive tree pruning residues, detoxified with the optimum activated carbon, was fermented with a commercial Saccharomyces cerevisiae yeast, obtaining a 100% theoretical maximum ethanol yield and a 56% bioconversion of fermentable sugars.
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•Integral use of a residue for production of 2G bioethanol and adsorbent was performed.•A regional waste was used both as raw material and as detoxifier to obtain bioethanol.•Two experimental routes were carried out to obtain optimal conditions in the process.•An efficient detoxification method was developed to enhance bioethanol production.•Activated carbon eliminated more than 50% of toxic compounds for the fermentation.
Assessment of the antioxidant activity of different types of natural compounds is a complex research area that encompasses various in vitro tests and in vivo studies. Sophisticated modern analytical ...tools permit the unambiguous characterization of the compounds present in a matrix. The contemporary researcher, knowing the chemical structure of the compounds present, can carry out quantum chemical calculations that provide important physicochemical information assisting the prediction of antioxidant potential and the mechanism behind the activity of target compounds before further experimentation. The efficiency of calculations is steadily improved due to the rapid evolution of both hardware and software. It is possible, consequently, to study compounds of medium or even larger size, incorporating also models that simulate the liquid phase (solution). This review contributes to the establishment of theoretical calculations as an inherent part of the antioxidant activity assessment process, having as a case study the complex mixtures of olive bioactive secoiridoids (oleuropein, ligstroside, and related compounds). The literature indicates great variability in theoretical approaches and models used so far for only a limited number of this group of phenolic compounds. Proposals are made for standardization of methodology (reference compounds, DFT functional, basis set size, and solvation model) to facilitate comparisons and communication of findings.
The olive psyllid Euphyllura olivina Costa (Homoptera, Psyllidae) causes considerable damage in olive groves in the Mediterranean basin, there by affecting production. To assess the rate of ...infestation and provide elements of integrated pest management, we monitored the life cycle and bio–ecology of this pest through population counts on the leaves and twigs of the tree from 29 March 2019 to 27 March 2020 at two relatively distant olive farms (Ain fares and Oued taria) in the wilaya of Mascara, Algeria. Our results showed that infestation was high on trees in the Oued taria farm. We found that E. olivina developed two generations per year, in spring, influenced by the climatic factors. The difference between the relative abundance of the different life stages (eggs, larval instar 1, 2, 3, 4 and 5, female and male) in the cardinals orientations was significant. Infestation was highest on the southern and central orientations of the tree. Populations fluctuations were significantly affected by season at both farms.
for the manuscript for the manuscript JCIS-24–2223 “Biochar from olive tree twigs and spent malt rootlets as electrodes in Zn-air batteries”, by Kottis et al.
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Biochars, i.e. porous ...carbons obtained by pyrolysis of biomass, can act as electrocatalysts for oxygen evolution and oxygen reduction reaction. In the present work, two biochars have been prepared by using materials of completely different biomass origin: olive-tree twigs and spent malt rootlets (brewery wastes). Both biomass species were subjected to pyrolysis under limited oxygen supply and then they were activated by mixing with KOH and pyrolysis again. The obtained biochars were characterized by several techniques in order to determine their structural characteristics and the composition of their active components. Despite their different origin, the two biochars demonstrated similar structural and compositional characteristics thus highlighting the importance of the pyrolysis and activation procedure. Both biochars were used as electrocatalysts in the operation of rechargeable Zn-air batteries, where they also demonstrated similar electrocatalytic capacities with only a small advantage gained by olive-tree-twigs biochar. Compared to bare nanoparticulate carbon (carbon black), both biochars demonstrated a marked advantage towards oxygen evolution reaction.
Agrivoltaic systems provide a promising solution for mitigating the competition for land between food and energy production. This study examines the performance of an agrivoltaic system in southern ...Spain, which integrates bifacial PV technology with three different olive cultivars. Different configurations of clearance height and PV modules tilt are analyzed. The findings indicate that PV modules tilted near the site's latitude achieve the highest energy yield, while vertically-oriented modules lead to the greatest olive yield. The variation in tilt angle has a more significant impact on PV yield, whereas the height of the PV modules primarily affects olive tree yield. To quantify the combined land productivity of energy and crop outputs, the land equivalent ratio (LER) is employed. The results demonstrated a maximum LER of 171% when modules are tilted at 20°, thereby enhancing overall land productivity. Moreover, the study reveals that olive trees display a moderate sensitivity to shading. These findings underscore the importance of optimizing the configuration of PV systems for dual land use in agrivoltaic while taking agricultural productivity into account.
•An agrivoltaic system of bifacial PV and three varieties of olive trees were studied.•The raytracing approach and olive light response were used to model the tree yield.•The influences of photovoltaic module height and tilt were quantified.•The peak land equivalent ratio (LER) of 71% resulted when PV panels were tilted at 20°.•The study revealed that olive trees displayed moderate sensitivity to shading.
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