Olive Stones Research Articles

Performance improvement in olive stone's combustion from a previous carbonization transformation

Under the framework of circular economy, agricultural wastes are an interesting carbon-based feedstock for thermal energy and power generation. Their use could extend the availability of biomass-based fuel and, at the same time, would reduce negative environmental effects. However, depending on the residues’ characteristics, their direct combustion in boilers presents some challenges which could be overcome with a carbonization pre-treatment. In this paper, the main mechanisms of thermochemical transformation of an abundant agricultural waste, olive stone, into biochar products via slow carbonization are analyzed, with emphasis on the effect of peak carbonization temperature. Thermogravimetric and differential scanning calorimetry analysis are used to evaluate the performance of the resulting biochars compared to raw olive stone in combustion processes and to assess the correlation between the peak carbonization temperature and compositional and fuel properties. Results show that with a prior treatment up to an optimum temperature of 800 °C the energy density is increased up to three times compared to the raw material. These findings suggest that carbonization of olive stones reduces the barriers to their direct use in current biomass boiler technology.

USING OLIVE STONE POWDER FOR STEEL CORROSION INHIBITION

corrosion of metals is the most significant and difficult life problems, especially its produce an economical losses, therefore, many researches carried out in various fields in order to reduce the bad effect of corrosion, particularly in acidic environments. Using corrosion inhibitors is one of the methods of prevention corrosion, which come up on organic and inorganic materials, in this study, dried Olive stone powder used as corrosion inhibitor in solutions of hydrochloric acid with concentrations of 0.5, 1 and 1.5 molarity at room temperature, where 10 gm per litter of acid. The corrosion rates of mild steel samples were measured using potentiostat device with reference of calomel electrode. The result shows that corrosion rate reduced by adding the Olive stone powder. The highest inhibition efficiency percent for acid solutions with concentration of 1.5 molarity is 82.9%, while the lowest was 64.1% in the 0.5 molarity solution, and in the 1 molarity solution was 77.6%. The chemical composition of the Olive stone powder is shown to be an organic matter of a high carbon and hydrogen content making a carbonyl compound which has the greatest effect in inhibition corrosion in acidic solutions such as hydrochloric acid.

Standing out the key role of ultramicroporosity to tailor biomass-derived carbons for CO2 capture

The successful tailoring of the ultramicroporosity remarkably increases the CO2 uptake capacity of low cost-carbons derived by a simple one-pot physical activation of olive stones, coffee grounds, almond shells and grape seeds. A porous network dominated by ∼40–46% of ultramicropores below 0.5 nm and no significant presence of pores above 0.7 nm boosts the CO2 uptake at 1 bar and 298 K around 40% compared to materials with similar micropore volume. A slight ultramicropore widening causes the drop to a standard pattern that depends mainly on the micropore volume.The detailed analysis of the CO2 isotherms within the Dubinin´s theory provides simple clues for the optimization of carbons for CO2 capture at ambient temperature and atmospheric pressure. Thus, a general pattern of around 7.2 mmol of CO2 captured per cm3 of ultramicropores is found for a variety of activated carbons and carbide derived-carbons with characteristic energy Eo of 29–22 kJ/mol. This feature is typical of materials with average micropore sizes from 0.65 to 1 nm. An enhancement of up to 10 mmol CO2/cm3 is achieved by carbons with Eo ranging between 30 and 32 kJ/mol which correlates with an extremely homogeneous porosity with average dimensions around 0.5 nm.The excellent fit of the present carbons into general patterns exclusively based on the textural features reveals no significant influence of their surface functionalities on the CO2 adsorption performance.

On the removal of hexavalent chromium by olive stones coated by iron-based nanoparticles: Equilibrium study and chromium recovery

Abstract In this work hexavalent chromium, Cr(VI), removal in aqueous solution by olive stones coated by zero-valent iron and magnetite nanoparticles was investigated. The Cr(VI) removal test results showed that the coated biomass adsorption capacity significantly increased (2.54 and 4.11 mg Cr g−1) when compared to the uncoated one (1.48 mg Cr g−1). Optimal removal conditions were reached by fixing the operating parameter values for pH, mass concentration and contact time equal to 3, 2.5 g L−1 and 120 min for the uncoated and equal to 2, 1.5 g L−1 and 120 min for the coated biomasses, respectively. Both Cr(VI) and Cr(III) recovery, after 5 cycles of use, was investigated using different solvents and operative conditions (with and without sonication), showing that remarkable Cr recovery was possible using the more environmentally friendly washing procedure. A possible Cr(VI) removal mechanism will be here proposed and discussed, considering both reduction and adsorption contribution towards Cr(VI) removal in aqueous medium and capable to justify the obtained results.

Factors Influencing NO₂ Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry.

The textural properties and surface chemistry of different activated carbons, prepared by the chemical activation of olive stones, have been investigated in order to gain insight on the NO2 adsorption mechanism. The parent chemical activated carbon was prepared by the impregnation of olive stones in phosphoric acid followed by thermal carbonization. Then, the textural properties and surface chemistry were modified by chemical treatments including nitric acid, sodium hydroxide and/or a thermal treatment at 900 °C. The main properties of the parent and modified activated carbons were analyzed by N2-adsorption, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques, in order to enlighten the modifications issued from the chemical and thermal treatments. The NO2 adsorption capacities of the different activated carbons were measured in fixed bed experiments under 500 ppmv NO2 concentrations at room temperature. Temperature programmed desorption (TPD) was applied after adsorption tests in order to quantify the amount of the physisorbed and chemisorbed NO2. The obtained results showed that the development of microporosity, the presence of oxygen-free sites, and the presence of basic surface groups are key factors for the efficient adsorption of NO2.

The Behavior of Olive Stone Powder at High Temperature Steel Corrosion

Corrosion of metals is the most significant and difficult life problems, especially its produce an economical losses, therefore, many researches carried out in various fields in order to reduce the bad effect of corrosion, particularly in acidic environments. Using corrosion inhibitors is one of the methods of prevention corrosion, which come up on organic and inorganic materials, in this study, dried Olive stone powder used as corrosion inhibitor in solutions of hydrochloric acid with concentrations of 0.5, 1 and 1.5 molarity at 40 and 55 , where 10 gm per litter of acid. The corrosion rates of mild steel samples were measured using potentiostat device with reference of calomel electrode. The result shows that corrosion rate reduced by adding the Olive stone powder. The highest inhibition efficiency percent for acid solutions with concentration of 1.5 molarity is 93.8% at 55 , while the lowest was 49.6% in the 0.5 molarity solution at 55 . The chemical composition of the Olive stone powder is shown to be an organic matter of a high carbon and hydrogen content making a carbonyl compound which has the greatest effect in inhibition corrosion in acidic solutions such as hydrochloric acid.

The Behavior of Olive Stone Powder at High Temperature Steel Corrosion

Corrosion of metals is the most significant and difficult life problems, especially its produce an economical losses, therefore, many researches carried out in various fields in order to reduce the bad effect of corrosion, particularly in acidic environments. Using corrosion inhibitors is one of the methods of prevention corrosion, which come up on organic and inorganic materials, in this study, dried Olive stone powder used as corrosion inhibitor in solutions of hydrochloric acid with concentrations of 0.5, 1 and 1.5 molarity at 40 and 55 , where 10 gm per litter of acid. The corrosion rates of mild steel samples were measured using potentiostat device with reference of calomel electrode. The result shows that corrosion rate reduced by adding the Olive stone powder. The highest inhibition efficiency percent for acid solutions with concentration of 1.5 molarity is 93.8% at 55 , while the lowest was 49.6% in the 0.5 molarity solution at 55 . The chemical composition of the Olive stone powder is shown to be an organic matter of a high carbon and hydrogen content making a carbonyl compound which has the greatest effect in inhibition corrosion in acidic solutions such as hydrochloric acid.

Olive mill wastewater pretreatment by combination of filtration on olive stone filters and coagulation–flocculation

ABSTRACTIn the present study a new combined process, comprising filtration of raw olive mill wastewater (OMWW) on two successive olive stone (OS) filters followed by a coagulation–flocculation, was developed in order to perform an efficient pretreatment of OMWW. The results show that the use of OS filter leads to a higher removal of total suspended solids (TSS) and fatty matter (FM) from the raw OMWW (about 82.5% and 73.8%, respectively) and a depletion of total phenolic compounds (TP) and chemical oxygen demand (COD) (11.3% and 23.2%, respectively). The coagulation–flocculation was then applied to improve the removal of TP and COD from the filtered OMWW. For this purpose, a full-factorial design was used to study the effect of different factors involved in coagulation–flocculation. The studied variables were: pH (5–8), coagulant type (ferric chloride; FC and aluminum sulfate; AS), coagulant concentration (250–1000 mg/L) and flocculant (Anionique polyelectrolyte Superfloc A120 PWG) concentration (1–5 mg/L). The results reveal that the use of 250 mg/L FC and 5 mg/L flocculant at an acid pH (around 5) allows for, respectively, a removal of TP and COD of about 10.8% and 31.3%.

Chemical looping combustion of biomass: CLOU experiments with a Cu-Mn mixed oxide

Chemical looping combustion (CLC) is a low-cost CO2 capture technology with a low energy penalty. Bio-energy with CO2 capture and storage (BECCS) opens up the possibility for negative CO2 emissions involving the removal of CO2 already emitted into the atmosphere. The oxygen needed for combustion in CLC processes is supplied by a solid oxygen carrier circulating between the fuel reactor and the air reactor. In this work, the combustion of different types of biomass, such as pine sawdust, olive stones and almond shells, was studied in a continuous 1.5kWth CLC unit. A mixed Cu-Mn oxide was used as the oxygen carrier. This material releases gaseous oxygen when reduced, resulting in Chemical looping combustion with oxygen uncoupling (CLOU). The released oxygen reacts with both the volatiles and char generated inside the fuel reactor when biomass is fed into it. The oxygen carrier is reoxidized in air inside the air reactor. High CO2 capture and 100% combustion efficiencies were achieved with this Cu-Mn oxygen carrier. The oxygen concentration inside the air reactor did not affect CO2 capture efficiency under the studied conditions.

Comparative study of the adsorption of paracetamol from aqueous solution on olive stones and date pits

Comparative study of the adsorption of paracetamol from aqueous solution on olive stones and date pits

Valorization of olive stones into a granular activated carbon for the removal of Methylene blue in batch and fixed bed modes

Valorization of olive stones into a granular activated carbon for the removal of Methylene blue in batch and fixed bed modes

Olive mill wastewater phenolic compounds adsorption onto active olive stones: equilibrium isotherms and kinetics study

Phenol, being the major wastewater pollutant has adverse effects on the human health. Various biological and non-biological methods are used for removal of the phenol from wastewater such as adsorption, photodecomposition, volatilisation and others. The present study is focused on studying the environmental state of art of olive mills operating in the southern areas of Tunisia. It also investigates the feasibility of transforming olives solid residue into an effective, high capacity and low cost adsorbent for total phenol removal from olive mill wastewater (OMWW). Results indicated that the used activated olive stones, with 368.3 m2/g BET surface area, exhibit high total phenol adsorption capacity. Adsorption equilibrium is represented by Langmuir isotherm model (Q0 = 333.3 mg/g). Total phenol adsorption kinetics is best modelled by pseudo-second order reaction rate and Dumwald-Wagner (intra-particle) diffusion model. Reduction of the total phenol content in OMWW is achieved in mini column test of activated olive stones fixed bed adsorption.

Olive mill wastewater phenolic compounds adsorption onto active olive stones: equilibrium isotherms and kinetics study

Olive mill wastewater phenolic compounds adsorption onto active olive stones: equilibrium isotherms and kinetics study

Viability of using olive stones as lightweight aggregate in construction mortars

This article presents the results of a research project which studies the feasibility of substituting -in cement mortars- the most commonly used lightweight aggregates in Spanish building constructions (i.e. expanded clay), by waste from the olive industry. Spain is the world's largest producer of olive oil and olives, being therefore the main producer of olive-stone waste. These olive stones are currently used as biomass. To determine the viability of substitution, an experimental plan was designed. The objective of this plan was to add three different olive stone formats (entire, crushed and calcined) in cement mortars, using similar percentages additions as the ones used by the manufacturers of lightweight expanded clay mortars. From the results obtained it can be concluded that it is feasible to replace expanded clay by olive stones waste, obtaining mortars with lower densities, up to 30%, and improved compressive strength, up to 20% compared to lightweight expanded clay mortars.

Neural fuzzy modelization of copper removal from water by biosorption in fixed-bed columns using olive stone and pinion shell

Continuous copper biosorption in fixed-bed column by olive stone and pinion shell was studied. The effect of three operational parameters was analyzed: feed flow rate (2–6 ml/min), inlet copper concentration (40–100 mg/L) and bed-height (4.4–13.4 cm). Artificial Neural-Fuzzy Inference System (ANFIS) was used in order to optimize the percentage of copper removal and the retention capacity in the column. The highest percentage of copper retained was achieved at 2 ml/min, 40 mg/L and 4.4 cm. However, the optimum biosorption capacity was obtained at 6 ml/min, 100 mg/L and 13.4 cm. Finally, breakthrough curves were simulated with mathematical traditional models and ANFIS model. The calculated results obtained with each model were compared with experimental data. The best results were given by ANFIS modelling that predicted copper biosorption with high accuracy. Breakthrough curves surfaces, which enable the visualization of the behavior of the system in different process conditions, were represented.

Pyrolysis kinetics of the lead-impregnated olive stone by non-isothermal thermogravimetry

Abstract The thermal behavior of the lead-impregnated olive-stone during pyrolysis was investigated via thermogravimetric analysis at different heating rates under an inert atmosphere of nitrogen to study the effect of the metal during the thermal process. Thermogravimetric curves showed a little increase of the degradation temperature of hemicellulose and cellulose because of the presence of the metal when the material impregnated with lead was tested. Therefore, calculated kinetic parameters varied slightly after impregnation with lead. Apparent activation energies were 119.72, 238.65 and 68.76 kJ/mol for hemicellulose, cellulose and lignin fractions in raw olive stone and 119.40, 257.00 and 68.46 kJ/mol for the same fractions in the lead-impregnated olive stone.

A kinetics, isotherms, and thermodynamic study of diclofenac adsorption using activated carbon prepared from olive stones

ABSTRACTThe objective of this work was to study the efficiency of activated carbon prepared from agricultural waste (olive stones; OS) on diclofenac (DCF) adsorption in aqueous solutions. The prepared charcoals were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM)/Energy Dispersive X-Ray Analyser (EDX), and Brunauer–Emmett–Teller (BET) analysis techniques. The results show that DCF adsorption is favorable in acid medium and low temperature. The adsorption kinetics follows a pseudo-second-order kinetic model. The adsorption was found to be spontaneous (ΔG° < 0) for OS600°C, whereas the negative values of the enthalpy (ΔH°) suggest an exothermic adsorption for both adsorbents.

Olive tree varieties cultivated for the great Baetican oil trade between the 1st and the 4th centuries ad: morphometric analysis of olive stones from Las Delicias (Ecija, Province of Seville, Spain)

During the excavations of a Roman amphora workshop and oil mill of the 1st–4th century ad in Las Delicias, Genil valley, Ecija, Spain, large quantities of charred olive stones were recovered. The assemblages discovered in the pottery kilns demonstrate the use as fuel of olive residues, which were obtained from the extraction of the oil in the nearby mill. The abundance of material offered the opportunity to study the infra-specific diversity of the olives growing in the province of Baetica, which is known to have been an important oil-producing region during the Roman Empire. In total, 335 intact charred archaeological olive stones were analysed using geometric morphometry (outline analysis) and compared with several current morphotypes. These have been identified within a set of dimensional references of the stones established from the morphometric study of current varieties and wild populations, including genuinely wild and feral forms of olives, from various areas around the Mediterranean. The morphotype mainly found in wild populations was widely represented among the olive stones from Las Delicias. A large proportion of the archaeological stones were however close to various domesticated forms, which reflect the history of the region and of its varied cultural Mediterranean influences, Punic, Greek and Roman. Moreover, intermediate forms between two distinct morphotypes were identified. They suggest that hybrid olive trees derived from crosses among domesticated varieties and also between domesticated and wild forms, were grown in Las Delicias. In the Genil valley, Roman olive cultivation was based on a set of local olives which included wild and domesticated varieties from various origins, and whose diversity arose from breeding for improvement of varieties.

The severity factor as a useful tool for producing hydrochars and derived carbon materials.

The main purpose of this study was to understand the effect of time and temperature during the hydrothermal carbonisation (HTC) of olive stones (OS). For that purpose, the severity factor was introduced, by which the effect of the HTC conditions on the resultant products could be described. HTC was carried out at various temperatures (160, 180, 200, 220 and 240°C) and times (3, 6, 12, 24 and 48h) for producing 25 hydrochars. The yield to hydrochar varied from 70 to 50%. Hydrochars were all submitted to thermogravimetric and elemental analysis. The liquid fractions were also recovered and analysed in order to valorise OS as completely as possible. Thus, highly added-value products such as furfural and 5-hydroxymethylfurfural were detected. At the highest temperature and time, the hydrochar elemental composition was similar to that of lignite coals. Hydrochars were further carbonised at 900°C, leading to materials with surface areas as high as 1200m2g-1 and with narrow pore size distributions centred on 0.5nm. The severity factor allowed finding clear tendencies in the production of hydrochars and derived carbons in terms of yield, composition, and surface area, which would have been hardly analysed if the effects of temperature and time had to be considered separately. We proved that the severity factor, which use is quite uncommon in studies dealing with materials production, is a valuable tool for studying the effects of HTC experimental conditions.

Preparation and Characterization of Activated Carbon from Household Waste Foods

Waste food residues are considered as suitable raw materials for the production of low cost adsorbents. In this work, activated carbons was perpetrating from household waste food (orange peels, banana peels, walnut shells, olive stones and their mixture). Chemical carbonization at 500?C for 1.5hr was used to prepare carbons and their activation by KOH and CaCl2 solutions for 24h. Then added 0.1g of activated carbons to the solution of blue dyeprepared laboratory to demonstrate the activation of the types of activated carbons prepared toremove the blue dye. The results indicated that characteristics (yield, burn off, density, moisturecontent, ash content, pore volume, porosity percent, Iodine number, methyl blue number andremoval percent of methyl blue) for all activated carbons were compared with commercialactivated carbon. It has been found that activated carbon from orange peels and mixturesactivated with CaCl2 had the best adsorption properties reach to the (80, 77.5)% removal bluedye respectively and iodine numbers (741, 735)mg/g . This low coast activated carbons can beused for wastewater treatment.