Brazil Nut Shell Research Articles

The potential of third-generation biodiesel from Tolypothrix sp. CACIAM22 as a feedstock

Renewable energy has been recognized as an alternative to fossil fuels as a step to transform the energy produced and consumed worldwide. Cyanobacteria and microalgae are currently being considered as substitutes to the traditional feedstock used to produce biofuels due to their ability to achieve high amounts of lipids under cellular stress conditions. The aim of this study was to investigate the utilization of Tolypothrix sp. CACIAM 22 cyanobacterial biomass as a feedstock for biodiesel production, specifically by examining the effects of supplementing with hydrolysate of Brazil nutshell (HBNS) on biomass generation, lipid production, fatty acid composition, and quality of synthesized biodiesel. The supplementation of HBNS led to a significant increase of 12g.L−1 in wet biomass production. The lipid content reached 41 % of the biomass produced in HBNS supplemented cultures when nitrate source was deprived. The quality evaluation of cyanobacteria-derived biodiesel was performed using Biodiesel Analyzer ver 2.2 software, revealing superior quality compared to biodiesel produced from plant sources. The biodiesel exhibited values of 23 h for oxidative stability, 65 for cetane number, and an iodine index of 31 (g I2. 100 g−1fat), indicating promising potential as a renewable source. This study is the first to utilize HBNS as an organic supplement for cyanobacteria culture medium and assess its impact on biomass and lipid production in Tolypothrix sp., supporting the hypothesis of utilizing this biomass as a renewable feedstock for biodiesel production as a viable alternative to plant sources based on biomass production, lipid productivity, and biodiesel quality.

Improving biomass fuel obtained from Brazil nut residues via torrefaction: A case of kinetic and thermodynamic study

The residues of Brazil nuts (Bertholletia excelsa) were evaluated, in their natural state and in torrefied form, for their energy potential after pyrolysis. Samples of shells (BNS) and husks (BNH) were torrefied at 220, 260 and 300 ºC for 30 and 60 min, and were characterized for their chemical and energetic composition. It was also determined which samples showed, simultaneously, the lowest hemicellulose content and the highest cellulose content after torrefaction via analysis of the decomposition profile at 10 ºC/min under pyrolysis. The evolution of gases such as H2O, CO2 and/or C3H8, and CH4 was observed by simulated pyrolysis on a microscale in a thermogravimetric analyzer coupled to a mass spectrometer (TGA-MS). In addition, the kinetics of the pyrolysis of untorrefied and torrefied samples were evaluated using the Flynn-Wall-Ozawa (FWO) and Vyazovkin (VYZ) models in order to obtain the activation energy, pre-exponential factor and thermodynamic parameters. The predominant reaction mechanism was determined by Criado Master-plot method. The mean value of the activation energies ranged from 132.24 to 134.95 kJ/mol for BNS, from 135.53 to 138.47 kJ/mol for ST263, from 149.10 to 150.96 kJ/mol for BNH and from 145.83 to 148.14 kJ/mol for HT263. It was found that D2 and D4 diffusion mechanisms are prevalent in the decomposition of untorrefied samples, while torrefied samples were better adjusted to the F1/A2/A3/A4 overlapping nucleation models. High pre-exponential factor values indicated the presence of multiple intermolecular collisional reactions. The thermodynamic parameters evaluated, as well as the variations in enthalpy, Gibbs free energy and entropy, indicated that the evaluated process is endothermic, though requires little energy. As a whole, in view of the optimized parameters and elevation of the thermal stability of the material, the results demonstrate good potential for the use of Brazil nut shells and husks torrefied at 260 ºC for 30 min as biochar. In addition, pyrolyzed Brazil nut residues also have great potential in the production of bio-oil and biogas, in view of the high content of volatile matter released during the decomposition of the hemicellulose and lignin.

Removal of Fe and Mn ions from groundwater using activated carbon obtained from waste products of Brazil nut and andiroba cultivation in the Amazon region

Brazil nut (Bertholletia excelsa Bonpl.) biomass waste and andiroba (Carapa guianensis Aubl.) biomass waste were used as precursors in the production of activated carbons for removing Fe and Mn ions from groundwater. Activated carbon materials were prepared via carbonization and chemical activation using KOH and exhibited high specific surface areas of 1121 m2 g−1 (activated carbon from Brazil nut shells) and 2411 m2 g−1 (activated carbon from andiroba). These samples were modified by treatment with HNO₃ under microwave heating. The increase in surface acidity was confirmed through measurements of the pH at the point of zero charge and Boehm titration analyses, which identified the presence of phenolic, carboxylic, and lactonic groups. The modified activated carbons showed good adsorption capacity for the tested metal ions regardless of the precursor used. The achieved removal rates were greater than or equal to 85%, reaching values close to 100% for Fe removal using the carbon prepared from andiroba biomass waste. The antimicrobial activity assay indicated that the modified activated carbon impregnated with Ag+ ions exhibited antibacterial activity against Escherichia coli bacteria. The results are promising and suggest the feasibility of using the investigated residues as precursors for activated carbons and have good physicochemical properties.

Synthesis of biochar modified with 12-tungstophosphoric acid for the selective conversion of isoeugenol to vanillin

A heterogeneous acid catalyst was synthesized by anchoring 12–tungstophosphoric acid (HPW) onto biochar derived from Brazil nut shells (Bertholletia excelsa). This catalyst was used for the synthesis of vanillin from isoeugenol, employing hydrogen peroxide in acetonitrile solvent. The HPW-functionalized biocatalyst was prepared using a sonication method, which avoids the need for toxic and corrosive solvents, effectively incorporating tungsten at a mass proportion of 25%. Characterization of the catalysts utilized various techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and ultraviolet–visible spectroscopy. 30HPW/CC(200–2) exhibited high selectivity for vanillin (55%) with a significant conversion rate (69%). Over four cycles, selectivity and conversion remained consistently above 56% and 45%, respectively. The results presented in this study have the potential to promote a more sustainable vanillin production process, a valuable additive in the food and perfume industries, renowned for its high economic value.

CO2 capture by microporous carbon based on Brazil nut shells.

The increase in burning, deforestation, and the exorbitant use of fossil fuels have contributed to the increase in carbon dioxide emissions; this gas is responsible for the intensification of the greenhouse effect and radical climate changes. In this way, it becomes necessary to find alternatives to reduce its emission. Porous carbon materials synthesized from lignocellulosic waste can be employed in technologies for capture and utilization of CO2 due to the advantages such as selectivity, low-cost synthesis, high surface area and pore volume, and thermal and chemical stability. Considering the availability of Brazil nut biomass residues in the Amazon region, this article proposes to synthesize activated carbon from the lignocellulosic residue using physical and chemical activation methods for CO2 capture. The analysis of N2 adsorption-desorption isotherms proves the predominance of a microporous structure when using the two synthesis methods described here. In physical activation, the surface area was 912 m2/g, while, in chemical activation, it was 1421 to 2730 m2/g. The sample treated via the chemical method (BS6-K1) showed better performance in CO2 adsorption, with adsorption results of 3.8 and 6mmol/g of CO2 at 25 ℃ and 0°C, respectively, at 101kPa. CO2 adsorption capacity is due to the high volume of ultramicropores. It is believed that the microporous carbon material synthesized from Brazil nut residues is an alternative precursor for carbon materials used as CO2 capture.

Biotechnology management in the Amazon and the production of polypropylene / Brazil Nut Shell fiber biocomposite

Biotechnology management in the Amazon and the production of polypropylene / Brazil Nut Shell fiber biocomposite

Activated carbon prepared from Brazil nut shells towards phenol removal from aqueous solutions.

The Brazil nut shell was used as a precursor material for preparing activated carbon by chemical activation with potassium hydroxide. The obtained material (BNSAC) was characterized, and the adsorptive features of phenol were investigated. The characterization showed that the activated carbon presented several rounded cavities along the surface, with a specific surface area of 332 m2g-1. Concerning phenol adsorption, it was favored using an adsorbent dosage of 0.75g L-1 and pH 6. The kinetic investigation revealed that the system approached the equilibrium in around 180min, and the Elovich model represented the kinetic curves. The Sips model well represented the equilibrium isotherms. In addition, the increase in temperature from 25 to 55°C favored the phenol adsorption, increasing the maximum adsorption capacity value (qs) from 83 to 99mgg-1. According to the estimated thermodynamic parameters, the adsorption was spontaneous, favorable, endothermic, and governed by physical interactions. Therefore, the Brazil nut shell proved a good precursor material for preparing efficient activated carbon for phenol removal.

Preparation and characterization of steam and CO2 activated carbon from Brazil nut shell

Activated carbon is a porous material with several industrial applications. In this research, brazil nut shell was used to produce activated carbon, a promising raw material based on its low cost and high quality. Also, nut processing generates an extensive amount of waste, requiring proper disposal. The carbon was produced at temperatures of 600, 700, and 800 °C and activated by physical method using steam or CO2. Yield was calculated, and the activated carbon was analyzed according to the following physical-chemical parameters: water content, volatile material, fixed carbon, ash, apparent density, and pH. Infrared spectroscopy and BET adsorption isotherms were also performed. The fixed carbon contents of the carbons produced at 700 and 800 °C remained above 84%. The pH values characterized them as basic. The surface areas of the carbon obtained at 800 °C were 397 ± 8 m2 g–1 and 325 ± 7 m2 g–1 in those which were activated by steam and CO2, respectively.

KOH activated carbons from Brazil nut shell: Preparation, characterization, and their application in phenol adsorption

Activated carbons named AC105 and AC11 were prepared from Brazil nut shells using the weight ratios of Brazil nut shells: KOH of 1:0.5 and 1:1, respectively. The prepared materials were characterized using different techniques and applied to remove phenol from the aqueous solution through adsorption. The characterization data showed that both materials presented similar properties, with AC11 exhibiting a slightly higher specific surface area (332.2 m2 g–1) than AC105 (314.3 m2 g–1). The kinetic study showed that AC11 reached the process equilibrium faster than AC105, and the Elovich model was best suited to the kinetic data for both adsorbents. The equilibrium data followed the Sips model; the maximum adsorption capacities were 55.16 and 68.52 mg g–1 for AC105 and AC11, respectively. The application of the materials in the treatment of a simulated industrial effluent showed removal efficiencies of 28.05% and 48.20% for AC105 and AC11, respectively. Therefore, through the adsorption results, AC11 proved to be more efficient towards phenol removal and is a promising alternative for treating wastewater containing this contaminant.

Nitrogen-doped activated carbons with high performances for CO2 adsorption

Nitrogen-doped activated carbons (NACs) were produced from Brazil nut shells (BNS) using a concurrent procedure of KOH-activation and N-doping using melamine (MM), hexamethylenetetramine (HMTA), or tetramethylamonium hydroxide (TMAOH). N2 physisorption results demonstrated the materials have SBET values ranging from 1755 to 2562 m² g−1. The XPS analysis evidenced that all NACs showed relative N-surface composition from 6.40% to 17.1%. Raman spectra and SEM images proved the N-doping caused a great damage to the surface of the materials. Low-pressure CO2 adsorption results demonstrated that qe values ranged from 4.16 to 5.30 mmol g−1. Amongst NACs, the material AC2MM showed the lowest SBET value (1755 m² g−1), the highest N surface content (17.1%), and the highest CO2 qe values (5.30 mmol g−1 at 273 K and 1.0 bar, and 22.60 mmol g−1 at 298 K and 45 bar). Thus, the results evidence that N-doping tends to contribute more for CO2 adsorption than extremely high surface area values.

Biochar mitigates bioavailability and environmental risks of arsenic in gold mining tailings from the eastern Amazon

Artisanal gold mining has generated tailings highly contaminated by arsenic (As) in Cachoeira do Piriá, eastern Amazon, leading to severe risks to the environment. Such risks should be mitigated considering the bioavailable concentration of the element, since it implies immediate damage to the ecosystem. The objective of this study was to evaluate the potential of biochars in mitigating the environmental risks of bioavailable As concentrations in gold mining tailings from underground and cyanidation exploration. The biochar addition increased mineral components, cation retention, phosphorus in all fractions, and organic and inorganic carbon. The bioavailability of As was reduced after adding the biochars, following the order palm kernel cake biochar > Brazil nut shell biochar > açaí seed biochar, with reductions of up to 13 mg kg−1 in the underground mining tailings and 17 mg kg−1 in the cyanidation mining tailings. These results contributed to the statistically significant reduction of the environmental risks in both mining tailings (6–17% in the underground mining tailings and 9–20% in the cyanidation mining tailings), which was emphasized by Pearson's correlation and multivariate analyzes. The incorporation of the bioavailable fractions of As (from sequential extraction) in the environmental risk assessment was a promising method for evaluating the efficiency of biochars in mitigating the damage caused by this metalloid in gold mining tailings.

Polymer composite produced with Brazil nut residues and high impact polystyrene

Solid residues from agroindustry often accumulate and cause environmental imbalance. An alternative to this is to use this residue as a reinforcement in polymers. The achievement of this work was to characterize a composite with a polystyrene matrix reinforced with Brazil nut shells residues. The residues were cleaned and ground to then produce the samples via injection molding with the proportions of 0%, 2.5% and 5% of load. The specimens were characterized using mechanical tensile testing and thermogravimetric analysis (TGA). The mechanical test showed that the composite with 2.5% of filler had greater stiffness and strength was improved by 5%. Thermal analysis showed an increase in the temperature for the beginning of the degradation of the M2.5 composite. The results confirm a potential application in the automotive industry for the polystyrene composite reinforced with Brazil nut shells.

Heat treatment of polymeric PBAT/PCL membranes containing activated carbon from Brazil nutshell biomass obtained by electrospinning and applied in drug removal

Abstract This work aimed to perform a heat treatment on biodegradable polymeric membranes produced by the electrospinning technique to be used in the retention of residual drugs from water. For this, a blend with a concentration of 20 % (w/v) was produced, composed of 75 % Poly(butylene adipate-co-terephthalate) (PBAT) and 25 % poly (e-caprolactone) (PCL) (w/w), solvated in chloroform (CL) and N,N-dimethylformamide (DMF) in the proportion of 85/15 % (v/v), respectively. A portion of 10 % (w/w) activated carbon from Brazil nut shell biomass (CA-BCB) was incorporated in the polymeric solution, which was subjected to electrospinning to obtain the polymeric membranes. Thermal treatments were then carried out on the surface of the electrospun membranes. The membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and membranes surface wettability by contact angle. The results of the micrograph images (SEM) showed that the incorporation of CA-BCB produced fibers with smaller diameters without changing the chemical structure of the polymers, which was confirmed by the FTIR analysis. With the addition of activated carbon, there was an increase in the thermal stability of the material, which was confirmed by TGA analysis. In the permeability tests carried out with distilled water (1290 kg h−1 m-2) and tetracycline hydrochloride solution (TCH), 1220 kg h−1 m-2 with 200 min of operation. A PBAT/PCL membrane retention capacity, with heat treatment and addition of CA-BCB, of approximately 67 % was verified. This result suggests that the membranes produced by electrospinning, together with a heat treatment, can be used to retain emerging pollutants.

Use of agro-industry residues as substrate for the production of Euterpe precatoria seedlings

ABSTRACT The availability of single assai palm (Euterpe precatoria) seedlings with good quality is a fundamental requirement to expand the cultivation of the species. This study aimed to assess the use of fruit agro-industry residues as substrate for producing single assai seedlings. The experiment was carried out under nursery conditions, in a completely randomized design, with four replications and eight plants per plot. Fifteen treatments were evaluated: a commercial substrate, four dry and crushed agro-industrial residues (Brazil nut shell, acerola pit, assai pit and cupuassu peel) and ten combinations of these materials in the proportion of 1:1. The following variables were also measured: shoot height; stem diameter; number of leaves; shoot, root and total dry mass; and Dickson Quality Index score. The substrate formulated with Brazil nut shell + acerola pit stood out for promoting a higher growth and dry biomass, resulting in seedlings with a better quality. The pure assai pit residue was not efficient for producing seedlings, but it showed a good potential when mixed in equal proportion with other materials (e.g. Brazil nut shell and cupuassu peel).

Production of Bertholletia excelsa Humb. & Bonpl., (Lecythidaceae) seedlings in microenvironments under different substrates

The lack of technological options for forest concessionaires to produce seedlings of native tree species in the Peruvian Amazon is a bottleneck for reforestation in the region. In this study, a new technology for seedlings production of low cost and accessible to producers was developed. Thus, the objective of this study was to evaluate the efficiency of using buckets as microenvironments under different substrates for the initial growth of Bertholletia excelsa seedlings. Forty days after germinating, the seedlings were transplanted to 115 cm³ tubes containing a standard substrate composed by sand + sawdust + charred sawdust in the proportion of 1:1:1 v/v. Afterwards, the tubes were settled in buckets (microenvironments) under a 100% shade net. The experimental design used in this study was fully randomized and the treatments were T1 = sand, T2 = sand + sawdust, T3 = decomposed Brazil nut shell and T4 = forest soil. The substrate T2 promoted the shoot length, root length, leaves number, shoot dry mass, root dry mass, total dry mass, and slenderness index in B. excelsa seedlings. Quality of B. excelsa seedlings produced in microenvironments was similar among treatments, regardless of the used substrate.

Efficient acetaminophen removal from water and hospital effluents treatment by activated carbons derived from Brazil nutshells

Activated carbons from Brazil nutshells were produced by ZnCl2-activation at different biomass: ZnCl2 ratios of 1.0:1.0 and 1.0:1.5 at 600 °C and the samples were denominated as BNS1.0 and BNS1.5, respectively. The obtained activated carbons were used in the adsorption of acetaminophen (paracetamol) and for the treatment of synthetic hospital effluents. Several analytical techniques were used to characterize the activated carbons. The N2 isotherms presented the SBET values of the BNS1.0 and BNS1.5 are very high, 1457 and 1640 m2 g−1, respectively. The FTIR and Boehm titration analysis demonstrated the presence of several surface functional groups on both ACs surfaces, which can influence the acetaminophen adsorption. The adsorption studies revealed that the maximum adsorption capacities (Qmax) are very high for both ACs; however, the BNS1.5 capacity is higher (411.0 mg g−1) than that of BNS1.0 (309.7 mg g−1). The thermodynamic assessments revealed that the process of acetaminophen adsorption is spontaneous, energetically favorable, and exothermic, and the magnitude of enthalpy is compatible with physisorption. Besides, it suggests that the acetaminophen adsorption on both ACs is dominated by van der Walls forces and microporous filling mechanism. The use of activated carbons for treatment of synthetic hospital effluents, containing different pharmaceuticals as well as organics and inorganic salts, presented a high percentage of removal (up to 98.83%). The adsorbent was magnificently regenerated up to 74% with a mixture of 0.1 mol L−1 NaOH + 20% EtOH solution and can be reused up to four cycles ensuring sustainable use of proposed adsorbent for acetaminophen removal from aqueous media. In the light of these results, it is possible to say that Brazil nutshell is an excellent raw material to prepare efficient ACs which can be successfully used in the treatment of real hospital effluents.

Mesocarp of Brazil nut (Bertholletia excelsa) as inspiration for new impact resistant materials

Aiming to produce bioinspired impact and puncture resistant materials, the mesocarp of the Brazil nut (Bertholletia excelsa) was characterized. The mesocarp composition was investigated by chemical extraction and its microstructure was analyzed by optical microscopy and microtomography (microCT). A compression test evaluated the force needed to open the mesocarp shell. Shore D hardness testing and nanoindentation measured the local mechanical properties at different length scales. Brazil nut mesocarp has a higher content of lignin (56%) than other nutshells and is mainly composed of sclereids and fibers cells arranged together and not in separated layers as usually found in nature. The mesocarp has an internal and external layer with fibers oriented from peduncle to opercular opening and a middle layer where entangled fibers are latitudinally oriented. To open a Brazil nut mesocarp, compression forces of 10 079 ± 1460 N (parallel to latitudinal section) and 14 785 ± 4050 N (perpendicular to latitudinal section) are needed. Such forces are higher than the forces needed to open most nutshells, if fracture force is normalized by shell thickness. The Shore D hardness test showed that hardness is uniform in the mesocarp, although it is higher in the center of the thickness than close to the inner or outer surface. The cell wall of fibers has a higher reduced modulus than the cell wall of sclereids although they have a similar hardness. These microstructural and mechanical results indicate that Brazil nutshell has great potential as a source for bioinspiration and motivates further studies.

Combustion properties of potential Amazon biomass waste for use as fuel

Biomass has great potential for the production of fuels with high volatility and reactivity. In the Amazon region, biomass waste is mainly from fruits, which generate a large amount of stone and shell. Therefore, there is a need for technology to advance the use of renewable energy. This study aims to evaluate the combustion properties of biomass waste by using thermogravimetric analysis (TG-DTG). Five residues were used: acai stone, cocoa shell, coconut shell, cupuacu shell and Brazil nut shell. TG curves show the mass loss from room temperature to 140 °C, which is related to the removal of moisture. The second mass loss is ascribed to volatile matter in the temperature range of 140–400 °C, and the third mass loss from 400 to 600 °C is due to the decomposition of fixed carbon. By evaluating the thermal properties such as volatile matter, moisture, ignition temperature and mean reactivity index, it can be said that the coconut shell sample has combustion features that lead to its better use as fuel, while the acai stone biomass presents unsatisfactory combustion properties among the biomasses studied. The higher heating value is an important property which defines the energy content and efficient use of these fuels, and thus, for the biomass samples, the following order of higher heating value can be observed: Brazil nut shell, acai stone, cupuacu shell, cocoa shell and coconut shell.

H3PO4-activated carbons produced from açai stones and Brazil nut shells: removal of basic blue 26 dye from aqueous solutions by adsorption.

The adsorption characteristics of C.I. basic blue 26 (BB26) from aqueous solutions onto H3PO4-activated carbons (ACs) produced from açai stones (Euterpe oleracea Martius) and Brazil nut shells (Bertholletia excelsa H. B. K) were investigated in a batch system. The ACs were characterized by XRD, FT-IR, N2 adsorption at 77K, mercury porosimetry, and acidity/basicity analysis. The pseudo-first-order, pseudo-second-order kinetic models and intraparticle diffusion model were used for the kinetic interpretations. The adsorption processes follow the pseudo-second-order kinetic model. The Boyd plots revealed that the adsorption processes were mainly controlled by film diffusion. Equilibrium data were analyzed by the Langmuir and Freundlich models, at different temperatures. The equilibrium data were best represented by the Langmuir isotherm. The adsorption processes were found to be favorable, exothermic, and spontaneous. The açai stones and Brazil nut shells-based ACs were shown to be effective adsorbents for removal of BB26 from aqueous solutions.

Adsorption of basic dyes onto activated carbon: Experimental and theoretical investigation of chemical reactivity of basic dyes using DFT-based descriptors

Adsorption of basic dyes, basic blue 26 (BB26), basic green 1 (BG1), basic yellow 2 (BY2) and basic red 1 (BR1) onto activated carbon surfaces were investigated. Activated carbons (ACs) were produced by thermal treatment at 800 °C, oxidation with HNO3 6 M and chemical activation with H3PO4 at 450 °C and açaí seeds (Euterpe oleracea) and Brazil nut shells (Bertholletia excelsa) were used as precursors. ACs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), analysis (TGA/DTA), N2-adsorption at 77 K, mercury intrusion porosimetry, evaluation of acidity/basicity, and determination of the point of zero charge (pHpzc). The molecular chemical reactivity of the dye molecules was investigated using the DFT-based reactivity descriptors, electrophilicity index (ɷ), chemical potential (μ) and chemical hardness (η), values were approximated in terms of the frontier molecular orbital energies, HOMO and LUMO. ACs produced by activation with H3PO4 were more effectives to remover the dyes tested, performances attributed to their pore structure and surface functional groups. The experimental and theoretical results of chemical reactivity show that BG1 and BB26 dyes are more reactive than BR1 and BY2 dyes.