Pyrolysis Of Shell Research Articles

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

Sustainable Downstream Separation of Itaconic Acid Using Carbon-Based Adsorbents

Separation of itaconic acid from aqueous solution has been explored using various carbon-based adsorbents obtained from the pyrolysis and KOH activation of coconut shell biomass. The best preparation conditions to obtain a tailored adsorbent for itaconic acid purification were identified via a Taguchi experimental design, where its adsorption properties were maximized. The best activated carbon was obtained via coconut shell pyrolysis at 750 °C for 4 h plus an activation with 0.1 KOH and a final treatment at 800 °C for 2 h. This adsorbent showed an adsorption capacity of 4.31 mmol/g at 20 °C and pH 3 with a surface area of 466 m2/g. Itaconic acid separation was exothermic and pH-dependent where electrostatic forces and hydrogen bonding were the main adsorption interactions. Calculated adsorption rate constants for itaconic acid adsorption were 0.44–1.20 h-1. Results of adsorbent characterization analysis indicated the presence of a crystallization of itaconic acid molecules onto the activated carbon surface where 3–4 molecules could interact to form the clusters. This organic acid was recovered from the adsorbent surface via desorption with water or ethanol, thus facilitating its final purification. The best activated carbon obtained in this study is a promising alternative to perform sustainable and energy-efficient downstream separation and purification of itaconic acid produced via fermentation.

Analysis of the Physicochemical Characteristics of Biochar Obtained by Slow Pyrolysis of Nut Shells in a Nitrogen Atmosphere

The process of slow pyrolysis of seven nut shell samples, in a nitrogen-purged atmosphere, has been studied, as well as characteristics of biochar obtained. The heat carrier with a temperature of 400–600 °C (with a step of 100 °C) was supplied indirectly using a double-walled reactor. The heating rate was 60 °C/min. At increased temperature of the heating medium, a decrease in the amount of the resulting carbon residue averaged 6.2 wt%. The release of non-condensable combustible gas-phase compounds CO, CH4, and H2, with maximum concentrations of 12.7, 14.0, and 0.7 vol%, respectively, was registered. The features of the obtained biochar sample conversions were studied using thermal analysis in inert (nitrogen) and oxidative (air) mediums at 10 °C/min heating rate. Kinetic analysis was performed using Coats–Redfern method. Thermal analysis showed that the main weight loss (Δm = 32.8–43.0 wt%) occurs at temperatures ranging between 290 °C and 400 °C, which is due to cellulose decomposition. The maximum carbon content and, hence, heat value were obtained for biochars made from macadamia nut and walnut shells. An increased degree of coalification of the biochar samples affected their reactivity and, in particular, caused an increase in the initial temperature of intense oxidation (on average, by 73 °C). While technical and elemental composition of nut shell samples studied were quite similar, the morphology of obtained biochar was different. The morphology of particles was also observed to change as the heating medium temperature increased, which was expressed in the increased inhomogeneity of particle surface. The activation energy values, for biochar conversion in an inert medium, were found to vary in the range of 10–35 kJ/mol and, in an oxidative medium—50–80 kJ/mol. According to literature data, these values were characteristic for lignin fibers decomposition and oxidation, respectively.

Chemicals component yield prediction and kinetic parameters determination of oil palm shell pyrolysis through volatile state approach and experimental study

The green products from biomass pyrolysis open the way for the development and application of alternative fuels and chemicals. Until now, the pyrolysis kinetic studies are derived from solid-state approach (based on biomass as a reactant) which still faced drawbacks. A new approach, namely volatile state approach, is then developed with the volatile products as the main basis or reference to predict the mass fraction and yield as well as to determine the kinetic parameters from oil palm shell pyrolysis. The predicted results were then validated with the semi-batch pyrolysis experimental study. The oil palm shell has a biomass type number (NCT) of 9.57, volatile matter (YVM) of 71.90%-wt, and was pyrolyzed at 300 °C, 350 °C, 400 °C, 450 °C, and 500 °C. From the experiment, as many as 95 compounds in bio-crude oil (BCO) were successfully produced which contain 72.79%-wt water and 27.21%-wt organic compounds. According to the characterization of 15 BCO components, they were classified into carbohydrates, fatty acids, phenol, aromatics, and water. Furthermore, the activation energy of products formation revealed a temperature dependence as a second-order polynomial function. Ultimately, this approach shows its satisfying capability to predict each BCO component mass fraction and yield which closely fits the experimental results.

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.

Pengaruh Temperatur Pada Microwave Pirolisis Cangkang Kelapa Sawit dan Low Density Polyethylene Dengan Katalis Zeolite/Kalsium Oksida

In general, the use of oil palm parts can be utilized by industry, but it is different from oil palm shells which become waste. The high use of plastic is proportional to the waste generated. So far, both types of waste are problems that have not been resolved. The utilization of waste shell waste and low-density polyethylene using the pyrolysis method. Microwave technology has been widely used as a heat source in the pyrolysis process. The advantages of using microwaves in pyrolysis are fast and selective heating, efficient energy use, and control of pyrolysis products. This study aimed to determine the characteristics of Pyrolytic-oil from the pyrolysis of waste oil palm shells and Low-density polyethylene. The research was conducted using a microwave with temperature variations of 400oC, 450oC, 500oC, 550oC and 600oC. The composition of the main ingredients consisted of 75 grams of palm shells, 75 grams of low-density polyethylene plastic, 56.25 grams of a zeolite catalyst, 56.25 grams of calcium oxide and 131.25 grams of charcoal carbon absorber. The results showed the effect of temperature on pyrolytic-oil productivity; as the temperature increases, the product gas increases. The lowest density value at a temperature of 400oC is 966.8 Kg/m. The lowest viscosity at a temperature variation of 500oC is 2.1 Mpa.s. The highest acidity value is at a temperature of 550oC.

Pyrolysis of peanut shell: Kinetic analysis and optimization of thermal degradation process

Thermal degradation kinetics of peanut shell (PS) biomass has been investigated at the heating rates of 10, 15, and 20 °C/min using thermo-gravimetric (TG) and differential thermo-gravimetric (DTG) analyses techniques in the temperature range of ambient to 800 °C. The iso-conversional methods of Flynn-Ozawa-Wall (FOW), Kissinger-Akahira-Sunose (KAS), Starink, Tang, Vyazovkin, and Vyazovkin AIC have yielded activation energy Eα,varying from 186 to 226.97 kJ/mol. Effects of heating rate, temperature and nitrogen gas flow rate on the bio-char and bio-oil yields have been investigated using a fixed bed batch pyrolyser. The Box-Behenken design (BBD) of response surface methodology (RSM) has been used to optimize the process parameters. The average values of bio-oil and bio-char yields at the optimum conditions have been found to be 43.24 and 28.25 %, respectively. The product bio-oil is highly acidic and has the higher heating value (HHV) of 26.49 MJ/kg and the bio-char is rich in micronutrients.

Novel investigation of pyrolysis mechanisms and kinetics for functional groups in biomass matrix

Biomass, as a renewable and sustainable energy resource, can be converted into environmentally friendly and practically valuable biofuels and chemical materials via pyrolysis. However, the process optimization and pyrolysis efficiency are restricted by the limited perception of the complicated mechanisms and kinetics for biomass pyrolysis. Here, to establish an in-depth mechanism model for biomass pyrolysis, we presented a novel investigation for the thermal evolutions and pyrolysis kinetics of the functional groups in peanut shell matrix by using in-situ Fourier transform infrared spectrometry (in-situ FTIR) and thermogravimetric analysis-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS). The in-situ FTIR spectrum deconvolution for the solid matrix was innovatively introduced to identify and quantify the real-time evolution and thermal dynamics of the functional groups during peanut shell pyrolysis. The result for the first time proposed that the pyrolysis mechanisms of total OH at 20–380 °C, aliphatic C-Hn groups at 20–500 °C, CO groups at 260–500 °C, and C–O groups at 300–500 °C were dominant by diffusion and order-based chemical reactions. The TG-FTIR-MS analysis was conducted for the online monitoring of the released volatiles and gases, the amounts of which were in the sequence of CO > CO2 > aliphatic C–O-(H) > C–O-(C) in esters > aromatics > H2O > phenolic hydroxyl > aliphatic hydrocarbons > CO. The study established a novel methodology to evaluate the biomass pyrolysis mechanisms at the molecular level, which provided valuable information for developing advanced pyrolysis techniques on a large scale for sustainable ecosystem.

Investigation into Biomass Tar-Based Carbon Deposits as Reduction Agents on Iron Ore Using the Tar Impregnation Method

Increasing carbon deposits in iron ore to upgrade the reduction rate can be performed by impregnating iron ore in tar. Carbon containing iron ore was prepared from low-grade iron ore and biomass tar, which was generated from palm kernel shell (PKS) pyrolysis using the impregnation method. The optimum condition of the method was investigated by varying the tar-iron ore ratio (1 and 1.5) and impregnation time (0 and 24 h). After the carbonization of the tar–iron ore mixture in a flow-type quartz tubular fixed-bed reactor at 500 °C for an hour, the carbon deposits adhered well to surfaces of all iron ore samples. The carbon deposits increased when the ratio of tar-iron ore was enhanced. The effect of impregnation time on the formed carbon deposit only applied to the tar-iron ore ratio of 1, but it had a weak effect on the ratio of 1.5. The highest carbon content was obtained from the impregnation of a biomass tar–iron ore mixture with the ratio of 1.5 which was directly carbonized. In addition, the high water content of biomass tar affected the reformation of FeOOH at the impregnation within 24 h. Furthermore, the reduction reactivity of the obtained carbonized ore, which was observed using thermogravimetric analysis, was perceptible. The carbon deposits on iron ore were able to demote total weight loss up to 23%, compared to 8% of the dehydrated ore, during the heating process to 950 °C. The carbon content obtained from iron ore impregnation with biomass tar can act as reduction agents, thereby enhancing the reduction reactivity.

Enhanced adsorption of aqueous chlorinated aromatic compounds by nitrogen auto-doped biochar produced through pyrolysis of rubber-seed shell

ABSTRACT The adsorption of chlorinated aromatic compounds (CACs) on pristine biochar was often limited. Surface modification can greatly improve the adsorption capacity of biochar. In this work, by pyrolysis activation of rubber-seed shell wastes, nitrogen auto-doped biochar (RSS-NBC) was synthesized and used for purifying CACs-containing wastewater. Systematic characterization results showed that after proper treatment, the as-prepared RSS-NBC had high specific surface area, abundant surface oxygen- and nitrogen-containing functional groups, and nano-scale pore structure. Batch adsorption experiments were conducted with using three typical CACs probing pollutants, i.e. 1,2-dichlorobenzene (1,2-DCB), 2,4-dichlorophenol (2,4-DCP) and 2,4-dichlorobenzoic acid (2,4-DCBA). The adsorption experiments results showed that the maximum adsorption amounts of 1, 2-DCB, 2,4-DCP, and 2,4-DCBA could reach 2284, 1921, and 1142 mg/g at 298.15 K. Moreover, 90% of the equilibrium adsorption amount can be reached within 0.5 h. The adsorption kinetic results showed that the adsorption processes of the three CACs followed the pseudo-second-order rate model and were dominated by chemisorption. Also, the adsorption isotherms of 1, 2-DCB and 2, 4-DCP belonged to the Freundlich model and were valid for multilayer adsorption, while the adsorption of 2,4-DCBA followed Langmuir model and single-layer adsorption. The thermodynamics data indicated that the spontaneous adsorption process of 1, 2-DCB and 2, 4-DCP was endothermic while that of 2,4-DCBA was exothermic. After 5 cycles of adsorption-regeneration, the removal efficiency of RSS-NBC particles still remained more than 80% for the three typical CACs, indicating that it could be reused as an effective and retrievable adsorbent in the treatment of CACs-containing effluents.

Insights into Reaction Modeling and Product Characterization of Hazelnut Shell Pyrolysis

Insights into Reaction Modeling and Product Characterization of Hazelnut Shell Pyrolysis

Optimization of palm shell pyrolysis parameters in helical screw fluidized bed reactor: Effect of particle size, pyrolysis time and vapor residence time

The production of bio-oil from palm shell pyrolysis was investigated using a helical screw fluidized bed reactor setup. This study was done by investigating the effects of particle size, pyrolysis time and vapor residence time on pyrolysis product yields. The pyrolysis experiments were performed at different particle sizes, pyrolysis times and vapor residence times from 0.25 mm to 10 mm; 20 min to 60 min and 0.25 s to 15 s, respectively. The optimum condition for PS pyrolysis in helical screw fluidized bed reactor is at 2 mm particle size, 30 min pyrolysis time and 0.25 s vapor residence time to produce PS derived bio-oil of the highest yield of 73.86 wt% and higher heating value of 43.14 MJ/kg. Here, we report of the capability of helical screw fluidized bed reactor in handling large biomass particle size ranging up to 10 mm with marginal deteriorations of less than 1% and 3% for bio-oil yield and higher heating value respectively. This feature was attributed to the screw propeller design system in helical screw fluidized bed reactor which provided high mass and heat transfer at large particle size range which is 5 times of the particle size limit as recommended in previous studies. This finding would enable the possibility of helical screw fluidized based pyrolysis to be done in the absence of biomass size reduction processes to reduce process cost and complexity.

The Effect of Time on the Activation of Bayah Natural Zeolite for Application of Palm Oil Shell Pyrolysis

Oil palm shell (OPS) constitutes 60% of the waste generated during the processing of palm oil. However, OPS can potentially be converted into energy and chemicals through pyrolysis. The purpose of this study is to determine and analyse the effect of acid treatment time on the characteristics of natural zeolites, which were then applied to oil palm shell pyrolysis. The effect of the acid treatment time on the products of the pyrolysis was also studied. The acid treatment time was varied: 1, 3, and 5 hours. The crystallinity of the natural zeolites was determined by X-ray diffraction (XRD). Solid, liquid and gaseous pyrolysis products were observed. Proximate, ultimate, and heat analysis were performed on the solid product. The liquid product was characterised using gas chromatography-mass spectrometry (GC-MS). Gas Chromatography (GC) was performed to analyse the composition of the gases produced. The results obtained from this study indicate that longer reflux times reduced the crystallinity of the zeolites. The addition of the zeolite catalysts increased the liquid products of pyrolysis from 24.5 wt% over the parent to 24.6–37.1 wt% over the acid-treated natural zeolites. The reduction of oxygenated compounds in bio-oil was observed in the amount of acetic acid and acetone produced. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Pyrolysis of palm kernel shell using screw-assisted fluidization: effect of heating rate

Pyrolysis of palm kernel shell using screw-assisted fluidization: effect of heating rate

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.

Calcite modification of agricultural waste biochar highly improves the adsorption of Cu(II) from aqueous solutions

Calcite-modified biochar was developed as an inexpensive adsorbent for heavy metal immobilization. The biochar was prepared by pyrolysis of coconut shells under a N2 atmosphere at 600 °C and then modified by mixing with calcite in an aqueous solution. The surface area of the modified coconut biochar (CAL/BC) was relatively small (9.32 m2·g−1). The CAL/BC surface had CO, CO32- and CC functional groups. The maximum adsorption capacity of Cu(II) on CAL/BC was 213.9 mg·g−1 at 25 °C, and the removal efficiency was maintained at 87.7% even after four adsorption–desorption cycles. The adsorption process was described well by the pseudo-second order model (R2 = 0.9445–0.9976) and Langmuir adsorption model (R2 = 0.9908–0.9934), which meant that monolayer and chemical adsorption dominated. The dominant adsorption mechanisms of Cu(II) on CAL/BC were surface complexation, precipitation, and ion exchange. This study suggests that biochars prepared from two inexpensive materials (calcite and coconut shells) can be used as an adsorbent for effectively removing heavy metals from simulated aqueous solutions.

Physico-chemical and combustion analyses of bio-briquettes from biochar produced from pyrolysis of groundnut shell

The initiative of using biomass as a preference source of energy is vindicated by its availability, abundance, easy accessibility and its eco-friendly nature. This therefore calls for the conversion of agricultural wastes to usable form. This study is aimed to investigate the physicochemical and combustion properties of briquettes obtained from pyrolyzed biochar of groundnut shell. The groundnut shell biochar briquette bonded with cassava starch as binder were molded and analyzed. Proximate analysis, ultimate analyses, Scanning electron microscopy (SEM), Calorific values, density and compressive strength, among other properties, were determined for the fabricated briquettes. A high heating value of 45.20 MJ/Kg was recorded for groundnut shell biochar briquette compared to 25.20 MJ/Kg of raw groundnut shell briquette. While the ash contents of 5.12 % and 6.40 % were recorded for raw groundnut shell briquette and groundnut shell biochar briquette respectively. It took groundnut shell biochar briquette approximately 10 minutes to boil 1000 cm3 of water, while raw groundnut shell briquette boiled same quantity of water in 20 minutes. The finding of this study shows that the biochar obtained from the pyrolysis of groundnut shell is suitable for fuel briquette production. Â

Chloride release characteristics of desulfurization wastewater droplet during evaporation process using the single droplet drying method

The desulfurization wastewater evaporation technology is an effective way to realize zero-liquid discharge (ZLD). However, the release of chloride during the evaporation process is still a great challenge, which may cause severe chloride enrichment in the wastewater. In this work, the single droplet drying (SDD) method was utilized to investigate the chloride release characteristics during the evaporation process. The three periods of chloride release were first proposed based on the chloride release ratio and wastewater droplet's features (mass, temperature, and diameter). With the removal of the free moisture, the first period (Free water evaporation) was initiated, and almost no released chloride was detected; In the unstable shell period, 19.8% chloride would release there, mainly due to the increased droplet's temperature; Approximately 10% chloride would release during the shell pyrolysis period, which was directly related to the hydrolysis of the chloride-based salt hydrates in the evaporation particle. Besides, the chloride release characteristics at different cations species and ambient temperature were investigated. The desulfurization wastewater with a higher Mg2+ concentration would be more likely to release chloride during the evaporation process. With the temperature increased from 150 to 300℃, the chloride release ratio would improve from 14.56 to 29.8% due to the disruption of the shell and the hydrolysis degree at a higher temperature. In practical engineering practices, a balance point between chloride release and evaporation efficiency should be found, and the Mg2+ in the wastewater should be pre-treated before entering into the evaporation system.

Catalytic pyrolysis of coconut shell: a study on product distributions, optimized response surface methodology, and catalytic mechanism of bio-oil production

Catalytic pyrolysis of coconut shell: a study on product distributions, optimized response surface methodology, and catalytic mechanism of bio-oil production