Pyrolysis Of Walnut Shell Research Articles

Analyzing Solar Pyrolysis Process of Walnut Shells: Thermal Biomaterial Behavioral Outcomes

This paper presents a new experimental method for the thermal analysis of solar pyrolysis of walnut shells. The method consists of two types of thermal experiments: (A) the pyrolysis of walnut shells, and (B) the heating-cooling of the biochar obtained during experiment A. Nutshells are a waste product from the pecan nut industry. The state of Sonora, Mexico, produces large volumes of walnuts and their residue. Likewise, this region has a considerable solar resource. The motivation of this study is to obtain biochar - a bi-product of high commercial value used for soil enhancement - using solar energy and agro-industrial waste. In this experiment, biomass pyrolysis of 50g of nutshells was carried out inside a stainless-steel reactor heated with concentrated radiation from a solar simulator. Three different heat fluxes were used: 234, 482, and 725 W. The maximum reaction temperatures were: 382, 498, and 674 °C respectively. The composition of the pyrolysis gases (H2, CO, CO2, and CH4) was measured and the biochar obtained was characterized. Finally, the performance of the solar reactor allowed us to identify and differentiate between evaporation, pyrolysis of cellulosic material, and lignin degradation

Chemical structure and characterization of bio-oils isolated from walnut shells by different processes

This study investigated the products and properties of bio-yields obtained from different types of processes using the extraction and pyrolysis of walnut shells. Pyrolysis experiments were carried out with 10 g walnut shells at a pyrolysis temperature of 550 °C, a heating rate of 10 °C /1 min, a particle size of 1-1.5 mm, and a specific nitrogen gas flow rate. Aqueous extracts were obtained by placing the solid sample in a glass jar with methanol-chloroform (1:1 v/w) solvent indoors and away from light for five days. The obtained liquid samples were analyzed by Gas chromatography-mass spectrometry (GC-MS), Liquid Chromatography Mass Spectrometry (LC/MS-MS), and Fourier Transform Infrared Spectroscopy (FT-IR). Chemical composition analysis of the bio-oils revealed that phenol compounds were more concentrated in the aqueous extract process and volatile oil compounds that were more dominant in the pyrolysis process. The structural analysis results of the bio-oil showed that bio-oil products obtained from walnut shells can be used as fuel, composite film for different purposes, and value-added products. It can be said that the content analysis of liquid samples obtained as a result of pyrolysis and extraction of walnut shells was elucidated with advanced analytical techniques such as LC-MS/MS and GC-MS. The test results revealed that these products will be used in different areas such as energy and high-value-added products. This study provides researchers with a concrete prediction about the suitability of content-analyzed walnut shells.

Catalytic pyrolysis and in situ carbonization of walnut shells: poly-generation and enhanced electrochemical performance of carbons.

In this study, walnut shell (WS) was used as feedstock, incorporating lithium carbonate (LC), sodium carbonate (SC), potassium carbonate (PC), and potassium hydroxide (PH) as pyrolysis catalysts and carbonization activators. A one-step method that allows catalytic pyrolysis and carbonization to be carried out consecutively under their respective optimal conditions is employed, enabling the concurrent production of high-quality pyrolysis oil, pyrolysis gas, and carbon materials from biomass conversion. The effects of LC, SC, PC, and PH on the yield and properties of products derived from WS pyrolysis as well as on the properties and performance of the resulting carbon materials were examined. The results indicated that the addition of LC, SC, PC, and PH enhanced the secondary cracking of tar, leading to increased solid and gas yields from WS. Additionally, it increased the production of phenolic compounds in bio-oil and H2 in syngas, concurrently yielding a walnut shell-based carbon material exhibiting excellent electrochemical performance. Specifically, when PC was used as an additive, the phenolic content in the pyrolysis oil increased by 27.64% compared to that without PC, reaching 74.9%, but the content of ketones, acids, aldehydes, and amines decreased. The hydrogen content increased from 2.5% (without the addition of PC) to 12.75%. The resulting carbon (WSC-PC) displayed a specific surface area of 598.6 m2 g-1 and achieved a specific capacitance of 245.18 F g-1 at a current density of 0.5 A g-1. Even after 5000 charge and discharge cycles at a current density of 2 A g-1, the capacitance retention rate remained at 98.16%. This method effectively enhances the quality of the biomass pyrolysis oil, gas, and char, contributing to the efficient and clean utilization of biomass in industrial applications.

Enhancement of higher alcohols selectivity in Fischer-Tropsch synthesis using Walnut and Almond shell derived biochars as Copper/Cobalt catalyst support

The production of higher alcohols from synthesis gas using biochar-supported copper-cobalt catalysts is investigated. Biochars were prepared via pyrolysis of Walnut shells and Almond shells and were subsequently activated through physical and chemical methods. A 15 wt% Copper and 5 wt% Cobalt was loaded on the activated biochars via the impregnation technique. The chemical and physical properties of the catalysts were studied using various methods. The catalytic performance of the catalysts was assessed in a fixed-bed microreactor at 20 bars, 320 °C, and, an H2/CO ratio of 2, and the results were compared with the γ-Alumina supported catalyst. Strong interaction between cobalt and copper particles and the formation of bimetallic CuCo2O4 species were observed. The catalysts' reducibility was enhanced by a factor of 1.42. The catalytic studies revealed a significant enhancement in the rate of carbon monoxide hydrogenation. The catalyst supported on low-cost Almond shell-derived biochar demonstrated the best performance. The total alcohol selectivity increased from 22.2 wt% to 34.2 wt%, and the C2+ alcohol selectivity rose from 78.3 wt% to 91.1 wt%, as compared to the industrial catalyst supported on alumina. However, the selectivity for C5+ liquid hydrocarbons decreased to 16.8 wt%. Notably, biochar-supported catalysts also exhibited good stability.

Thermo-catalytic decomposition of walnut shells waste over cobalt doped cerium oxide: Impact of catalyst on kinetic parameters and composition of bio-oil

This research work is aimed at investigating the pyrolysis of walnut shells mixed with cobalt doped cerium oxide and non-catalytic pyrolysis of walnut shells. The pyrolysis experiments were performed in a locally designed pyrolysis chamber. The oils from catalytic and non-catalytic pyrolysis were characterized with GC–MS. It was found that in case of catalytic pyrolysis, the bio-oil obtained has several short-chain compounds as compared to bio-oil obtained through non-catalytic pyrolysis. Thermogravimetric analysis was conducted to assess the kinetics of pyrolysis of biomass both with and without catalyst. The kinetic parameters were determined using Kissinger equation. The activation energy (Ea) values for the decomposition of hemicelluloses, cellulose, and lignin were found as 167.72, 181.35, and 191.22 kJ mol−1 for non-catalytic pyrolysis and 107.48, 121.79, and 137.57 kJ mol−1 for catalytic pyrolysis. Moreover, the optimumtemperature of pyrolysis was effectively reduced to 410 °C employing a catalyst, as opposed to the maximum temperature of 430 °C in the case of non-catalytic pyrolysis. Keeping in view the reduction in activation energy and improvement in quality of oil from catalyzed reaction in presence of cobalt doped cerium oxide, it can be concluded that the findings of this study can contribute to the development of a process for sustainable utilization of walnut shells as energy source.

Release of Sulfur and Chlorine Gas Species during Combustion and Pyrolysis of Walnut Shells in an Entrained Flow Reactor

The release behavior of sulfur and chlorine compounds into the gas phase of walnut shell particles (WNS) is studied with an entrained flow reactor. Experiments are carried out in nitrogen (N2), carbon dioxide (CO2) atmosphere and under air and oxy-fuel conditions at different temperatures (T = 1000–1300 °C) and stoichiometries (λ = 0.8–1.1). A total of 98.7% of fuel-bound sulfur volatilizes as sulfur dioxide (SO2), carbonyl sulfide (COS) and hydrogen sulfide (H2S) in the gas phase in N2 atmosphere at 1000 °C. As hydrogen chloride (HCl), 37.0% of the chlorine is released at this temperature. In CO2 atmosphere, a similar total release of sulfur and chlorine is observed (1000 °C). With each temperature increment, the release of SO2, H2S and HCl in the gas phase decreases (N2 and CO2 atmosphere). SO2 forms the major sulfur component in both atmospheres. In CO2 atmosphere, higher concentrations of COS were detected than in N2 atmosphere. Air and oxy-fuel combustion conditions show significantly lower SO2, COS and HCl concentrations as in N2 and CO2 atmosphere. No H2S is detected in the gas phase during any of the combustion trials.

Increase of bio-char yield by adding potassium salt during biomass pyrolysis

Low yield is one of the key factors restricting the preparation of bio-char. Some studies suggested that the bio-char yield could be increased by adding potassium salts during biomass pyrolysis. Up to now this process has not been well understood. Therefore, this study focused on analyzing the pyrolysis of walnut shell impregnated with KCl at 400–800 °C to further reveal its mechanism. Results indicate that the effective temperature range of KCl is from 400 to 600 °C, during which the yield and free radical concentration of bio-char are both increased. This phenomenon is caused by the deposition of volatiles on KCl. It is found that there is a positive linear relationship between the increase of bio-char yield and the content of KCl covered by volatiles. Moreover, the KCl increases the defective structure of bio-char that may be related to the formation of quinone group. In addition, we analyzed the effect of different potassium salts, which follow the order: KCl > K2CO3 ≈ KOH > K2SO4 > KAc.

Investigation of Pyrolysis of Walnut Shells and Pyrolysis Oil Quality

The energy demand is increasing in parallel with the technological developments and population in the world. Fossil fuels are the main source for this demand. As a result of energy production from fossil fuels, natural environment is adversely affected. Furthermore, many countries depend on the fossil fuels for their energy need. Researchers have been interested in alternative energy sources such as solar, biomass, and wind. There are many studies for investigating pyrolysis of lignocellulosic biomass. Studies mainly focused on the chemical structure of pyrolysis oil from different feedstocks. In this study, producing pyrolysis oil from walnut shells using pyrolysis reactor, investigating pyrolysis oil properties while comparing it with fossil fuels to determine if the oil can be used in internal combustion engines are investigated. The effect of pyrolysis reaction temperature on pyrolysis oil yield is studied. The results indicates that pyrolysis oil can be produced from walnut shells, the reaction temperature is an important factor on pyrolysis oil yield and pyrolysis oil has complex nature compare to fossil fuels.

Mathematical Modeling and Experiments on Pyrolysis of Walnut Shells Using a Fixed-Bed Reactor

Pyrolysis is a low-emission and sustainable thermochemical technique used in the production of biofuels, which can be used as an alternative to fossil fuels. Understanding the kinetic characterization of biomass pyrolysis is essential for process upscaling and optimization. There is no accepted model that can predict pyrolysis kinetics over a wide range of pyrolysis conditions and biomass types. This study investigates whether or not the classical lumped kinetic model with a three-competitive reaction scheme can accurately predict the walnut shell pyrolysis product yields. The experimental data were obtained from walnut shell pyrolysis experiments at different temperatures (300–600 °C) using a fixed-bed reactor. The chosen reaction scheme was in good agreement with our experimental data for low temperatures, where the primary degradation of biomass occurred (300 and 400 °C). However, at higher temperatures, there was less agreement with the model, indicating that some other reactions may occur at such temperatures. Hence, further studies are needed to investigate the use of detailed reaction schemes to accurately predict the char, tar, and gas yields for all types of biomass pyrolysis.

Catalytic reforming of tar and volatiles from walnut shell pyrolysis over a novel Ni/olivine/La2O3 supported on ZrO2

The effect of catalytic reforming of volatiles from pyrolysis of walnut shell using an innovative catalyst was investigated in this study. The analysis was conducted in a two-stage fixed bed reactor operated at 700–1100 °C. The prepared Ni/olivine/La2O3/ZrO2 catalyst had a significant performance on the catalytic tar reforming reactions. In the catalytic reforming of tar, the weight of catalyst is critical. However, it was observed that the tar reforming efficiency increased with increase in catalyst-weight and temperature. In addition, the highest tar reforming efficiency (98.9%) was attained with 20 g of Ni/olivine/La2O3/ZrO2. After 4 cycles of regeneration, tar reforming efficiency was kept stable. The product gas composition was highest at 1100 °C with a very low tar yield, which reduced from 18.1 to 2.1 wt% at 700–1100 °C. At varying reforming conditions, the product gas composition increased. The product-gas distribution varied at different steam flow rates (3–9 mL/h) as well as particle size (0.2–3.5 mm) and the highest yield was achieved with the smallest particle size (0.2 mm) of walnut shell thus confirming the superb catalytic activity of Ni/olivine/La2O3/ZrO2 for tar reformation into gases owing to high dispersion of ZrO2 in the shells.

Increase of Bio-Char Yield by Adding Potassium Salt During Walnut Shell Pyrolysis

Increase of Bio-Char Yield by Adding Potassium Salt During Walnut Shell Pyrolysis

Comparative study on one-step pyrolysis activation of walnut shells to biochar at different heating rates

Pyrolysis of walnut shells to biochar at 700 °C using N2 gas was compared to one-step activation using steam/KOH under four different heating rates (10–40 °C/min). Steam biochars developed better surface area property of 342–556 m2/g compared to others (19–135 m2/g) over the same heating rates; meanwhile, increasing heating rate caused functional groups alteration and was distinct on the surface area property as about six-fold and two-fold difference from the lower to higher rates were recorded in neutral char and the steam/KOH activated biochars respectively. Increasing heating rate affected the neutral and steam biochars’ Raman intensity ratio whereas trivial influence was recorded on KOH-biochars.

Alkaline pretreatment of walnut shells increases pore surface hydrophilicity of derived biochars

The surface chemistry and morphology of biochars produced by pyrolysis of walnut shells affects their utility for adsorption applications. Yet, little is known about surface interactions in the pores of these materials, mostly due to the challenging nature of accessing information at this length scale in a non-destructive manner. Here, for the first time, the relative adsorption strengths of solvents comprising different functional groups to internal (pore) surfaces of walnut shells and derived biochars were investigated using low-field nuclear magnetic resonance (NMR) relaxation time measurements to non-destructively probe interactions of fluids with pore surfaces. Carbon bonding state compositions of these materials with respect to distance from the particle surface were determined using X-ray photoelectron spectroscopy coupled with ion beam etching. Alkaline pretreatment was found to increase the hydrophilicity of both walnut shells and derived biochars. It was found to increase surface interactions with hydroxyl groups, and to decrease those with methyl groups. Results were contextualised by thermogravimetric analysis, scanning electron microscopy, and previous in-situ X-ray imaging results. Taken together, results showed that alkaline pretreatment may be used to modulate responses to pyrolysis temperature of several factors that affect adsorption properties including surface hydrophilicity, particle size, porosity, pore accessibility, and surface texture.

Selective hydrodeoxygenation of lignin-derived phenolics to cycloalkanes over highly stable NiAl2O4 spinel-supported bifunctional catalysts

Hydrodeoxygenation (HDO) of lignin-derived bio-oil offers a promising route for the production of advanced biofuels. However, the conventional HDO of lignin-derived bio-oil faces serious problems, such as low hydrocarbon yield and easy deactivation of catalysts. Herein, a novel reaction system consisting of a highly stable bifunctional catalyst (i.e., Ni−WOx/NiAl2O4) and a dodecane solvent was developed for the HDO of lignin-derived phenolics. The Ni0 species, derived from NiWO4 precursors on the NiAl2O4, were of small crystallite size and high dispersion, together with the strong oxophilicity of W, thereby exhibiting high activity. The use of a highly stable NiAl2O4 spinel support and the replacement of common solid acid with more stable WOx for the cleavage of CO bond accounted for excellent stability. The optimized 10Ni−15WOx/NiAl2O4 exhibited a high guaiacol conversion of 97.8% with a high cycloalkane yield of 83.8% under the optimum conditions (250 °C, 5 MPa H2, and 4 h). Cycloalkanes with a high yield over 90% were also obtained by the HDO of other complex lignin-derived compounds. More importantly, the catalyst always retained its initial activity for the HDO of guaiacol in five runs, with negligible coke formation. Subsequently, the HDO behavior of the bio-oil obtained from walnut shell pyrolysis was also studied. The relative content of cycloalkanes in the products reached 44.3% after the reaction. This study highlights the prospect of a highly stable catalyst consisting of hydrogenation metal and oxophilic promoter, and dodecane solvent to enable efficient production of cycloalkanes from the HDO of lignin-derived phenolics.

Novel insights into the enrichment of phenols from walnut shell pyrolysis loop: Torrefaction coupled fractional condensation.

Enriching high-value chemicals from the pyrolysis of agricultural and forestry waste is an efficient way to achieve sustainable development and large-scale application of biomass pyrolysis. Phenols, as important chemical raw materials, spices and food additives, have attracted widespread attention. Herein, a novel technical route of torrefaction pretreatment combined with fractional condensation in pyrolysis loop was proposed to enrich the phenols in liquid products. In this study, the enrichment of phenols from the pyrolysis loop of walnut shell under the combination of torrefaction and fractional condensation was explored using a fixed-bed pyrolysis reactor equipped with a three-stage condensation system. Simultaneously, the effects of torrefaction on feedstocks were investigated through a thermogravimetric analyzer based on the characteristics of feedstocks. The results showed that the torrefaction and pyrolysis loop had a negative impact on the pyrolysis efficiency and the yield of liquid products, while the change in the condensation efficiency depended on the combined effects of torrefaction and pyrolysis loop. In addition, phenols tended to be enriched in the second condensation stage, especially phenol, o-cresol, 4-ethylphenol. Importantly, torrefaction could significantly enrich phenols in the liquid products, and the enrichment of phenols is relatively increased by 109.44% at least. Moreover, the pyrolysis loop was also beneficial to the enrichment of phenols, which was at least 90% higher than that of walnut shell. This study provided a potential route to enrich high value-added products from the pyrolysis loop of lignocellulosic biomass.

Study of temperature variation of walnut shell and solid heat carrier and their effect on primary pyrolysis and volatiles reaction

Biomass pyrolysis by solid heat carrier is regarded to be efficient in heat transfer, high in tar yield and easier for reactor scale-up. However the transient behaviors in heat and mass transfer and complicate reactions, especially the volatiles reaction in the solid heat carrier phase, make it difficult to understand the relations between operating conditions and the conditions of actual reactions, and consequently the yield and composition of the products. This work studies these relations using a 4 mm layer of walnut shell as the biomass and some amounts of quartz sand as the solid heat carrier in a specially designed small reactor to simulate a finite element in a moving bed large reactor. The mean temperature of the walnut shell layer (T-WS) and the highest temperature of the quartz sand layer (T-QS-o) under various quartz sand preheating temperatures (PT, 600–900 °C) and various solid heat carrier-to-biomass mass ratios (Rs-b, 5:1–9:1) are determined and correlated with the walnut shell pyrolysis and volatiles reaction. The results show that T-QS-o and T-WS depend linearly on PT and Rs-b, but their difference varies from 39 to 108 °C. A reaction matrix is proposed and the oil yield is modeled by first order kinetics which decouples the roles of T-WS in WS pyrolysis and T-QS-o in oil reaction. It is found that the walnut shell pyrolysis is strongly influenced by heat transfer from quartz sand to walnut shell with activation energy of only 46.4 or 19.2 kJ/mol for varying PT or Rs-b, respectively. The oil reaction in the quartz sand layer reduces the oil yield and is dominated by the reaction of radical fragments that is weakly dependent on temperature, so the activation energy is also low, 4.8 or 2.9 kJ/mol for varying PT or Rs-b, respectively. The oil reaction in the quartz sand is extensive and more than 50% of it is converted to non-oil volatiles at T-WS of 350 °C.

Enrichment of phenolic products in walnut shell pyrolysis bio-oil by combining torrefaction pretreatment with fractional condensation

Walnut shell pyrolysis liquefaction experiments for phenolic enrichment were conducted using torrefaction pretreatment and fractional condensation simultaneously. Bio-oil composition was comprehensively analyzed for elements, functional groups and componential contents. After high-temperature torrefaction, the proportion of lignin pyrolytic products in pyrolysis organic vapors showed significant increment. Fractional condensation further separated water, acetic acid and other small molecular compounds, and improved the phenolic content in the target bio-oil. Compared with the traditional pyrolysis liquefaction technology, when 363 K water bath was utilized to recover 300 °C torrefied walnut shell pyrolysis vapors, the C/O ratio in bio-oil increased from 0.5 to 1.6, and the proportions of H in aromatic ring and phenolic OH increased by 150% and 400%, respectively. The total content of detectable phenols was enriched from 2.7 wt% to 13.3 wt%. The optimized scheme on improving economic efficiency was provided for offsetting torrefaction energy consumption and low bio-oil yield.

Experimental determination of walnut shell pyrolysis kinetics in N2 and CO2 via thermogravimetric analysis, fluidized bed and drop tube reactors

A thermogravimetric analyzer (TGA), a fluidized bed reactor (FBR) and a drop tube reactor (DTR) are used to study the effect of reactor type, heating rate and temperature on the pyrolysis of pulverized walnut shell particles in N2 and in CO2. These setups cover a temperature range of 400–1300 K with heating rates of 10−1 to 105 K s−1. The single first-order model in combination with an Arrhenius approach is used to describe the pyrolysis reaction. Derived activation energies for all setups show similar values (Ea,TGA = 71.96 kJ mol−1, Ea,FBR = 68.60 kJ mol−1 and Ea,DTR = 60.83 kJ mol−1), while an increase in the reactor temperature tend to lower the activation energy. Pyrolysis gas compositions in FBR and DTR reveal consistent trends towards lower H2O and higher CO contents with increasing reactor temperature. To evaluate the impact of CO2 on the solid conversion, TGA measurements in CO2 are used to determine gasification kinetics (Ea,g = 214.1 kJ mol−1, Ag = 71.96 s−1). CFD simulations using these kinetics in CO2 drop tube experiments let assume that the changed thermophysical properties of the gas and not the gasification reaction lead to the observed stronger conversion in CO2 compared to N2.

Catalytic fast pyrolysis of walnut shell for alkylphenols production with nitrogen-doped activated carbon catalyst

Alkylphenols are a group of valuable phenolic compounds that can be derived from lignocellulosic biomass. In this study, three activated carbons (ACs) were prepared for catalytic fast pyrolysis (CFP) of walnut shell to produce alkylphenols, including nitrogen-doped walnut shell-derived activated carbon (N/WSAC), nitrogen-doped rice husk-derived activated carbon (N/RHAC) and walnut shell-derived activated carbon (WSAC). Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were carried out to reveal the influences of AC type, pyrolytic temperature, and AC-to-walnut shell (AC-to-WS) ratio on the product distributions. Results showed that with nitrogen doping, the N/WSAC possessed stronger capability than WSAC toward the alkylphenols production, and moreover, the N/WSAC also exhibited better effects than N/RHAC to prepare alkylphenols. Under the catalysis of N/WSAC, yields of alkylphenols were significantly increased, especially phenol, cresol and 4-ethylphenol. As the increase of pyrolytic temperature, the alkylphenols yield first increased and then decreased, while high selectivity could be obtained at low pyrolytic temperatures. Such a trend was also observed as the AC-to-WS ratio continuously increased. The alkylphenols production achieved a maximal yield of 44.19 mg/g with the corresponding selectivity of 34.7% at the pyrolytic temperature of400°C and AC-to-WS ratio of 3, compared with those of only 4.67 mg/g and 6.1% without catalyst. In addition, the possible formation mechanism of alkylphenols was also proposed with the catalysis of N/WSAC.

Biosorption of Rare-Earth Elements From Aqueous Solutions Using Walnut Shell

Agricultural wastes are considered as green adsorbents that can work as an alternative to recover critical and scarce metals from secondary sources. Critical elements as rare earth elements (REEs) can be obtained from electronic wastes or tailings and could be recovered using these green alternatives. In this study, walnut shell (WS) was tested to determine whether several REEs can be efficiently retained by this green adsorbent. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Thermogravimetry and Differential scanning calorimetry (TG-DSC) were used to characterize WS before and after REE adsorption. Analytical performance of REE quantification was evaluated, besides of adsorption capacity and isotherms that were calculated in order to determine the model that fit well to REE adsorption. ICP-OES results indicated the lowest limit of detection and quantification (LOD and LOQ) with Eu (0.08 and 0.23ppb, respectively), nevertheless, quantification of other elements was also at the ppb level. In order to obtain the highest adsorption of metals, 75 and 2,000 µm particle sizes were studied, reaching >80% of adsorption with both sizes. Additionally, several pH values were tested in order to determine the optimum condition for maximal adsorption and adsorption capacity, noticing that pH 4 showed the best adsorption percentage (>85%, qe = 6.5 - 8mg/g). Langmuir isotherm model fitted well for Eu, La, Sm and Gd adsorption equilibrium. Characterization of WS was done using FTIR, TG-DSC and SEM. FTIR analysis showed several changes in the spectra after adsorption of REE tested but major changes were observed at the OH group, which shifted up to 31 cm-1 of wavelength. Additionally, TG-DSC showed that WS pyrolysis was divided in three stages: vaporization of moisture (about 10% of weight loss), thermal decomposition of hemicellulose, cellulose and lignin (higher than 60% of weight loss), and high-temperature calcination of residues (<25%). Finally, SEM characterization showed empty and filled pores of different sizes in WS after metal adsorption, and more rugged aspect was observed. This study reveals that WS is an efficient low-cost adsorbent for REEs and can be used for future recovery of these elements from secondary sources.