Pyrolysis Of Shell Research Articles

Pyrolysis and ex-situ vapor upgrading of pine nut shells over Ni- and Co-modified HZSM-5 catalysts to high-quality bio-oil and syngas

The ex-situ catalytic upgrading of pine nut shell pyrolysis vapor was conducted over Ni/HZSM-5 and Ni-Co/HZSM-5 catalysts using a fixed bed reactor. The effects of the catalytic temperature (500–800 °C) and pressure (0.1–0.6 MPa) on the yield and composition of the products were investigated. The physicochemical properties of bio-oil were visibly improved by increasing the temperature and pressure, and the products mainly contained light aromatic hydrocarbons, aliphatic hydrocarbons and phenolic compounds. The addition of Co significantly enhanced the deoxidation ability of the Ni-Co/HZSM-5 catalyst, and the BTXEN yield of the upgraded bio-oil increased to 15.3 mg/g with a heating value of 36.80 MJ/kg. Less water was generated in pressurized catalysts, and the syngas yield significantly increased with increasing pressure. Based on mechanistic considerations, atmospheric pressure catalysis favors alkylation, and high-pressure catalysis increases the syngas yield.

Pyrolysis of coconut shells for liquid smoke production: effect of integrated water scrubber on reduction of tar

Pyrolysis of coconut shells for liquid smoke production: effect of integrated water scrubber on reduction of tar

Pyrolysis of Mixed Date Stones and Pistachio Shells: Identification of Bio-Oil and Utilization of Bio-Char as Activated Carbon Precursor.

Thermal pyrolysis of mixed date stones and pistachio shells in a semi-batch reactor was addressed in this study. The highest yield of liquids (51.20 %) was produced at 500 °C, 90 min, 20 °C/min heating rate, and 50 mesh particle size. Under these conditions, yield of liquid from date stones and pistachio shells separately was 49.12 % and 47.67 %, respectively. The FT-IR results confirmed the presence of multiple oxygen-containing compounds in the bio-oil. Results from GC-MS declared that it was predominately composed of acids (57.57 %), esters (21.35 %), phenols (4.63 5), and alcohols (3.49 5). The obtained biochar was transformed into activated carbon (AC) by the optimized ZnCl2 activation method. The ideal AC was synthesized at 600 °C for 60 min using a 2 : 1 ZnCl2 : biochar impregnation ratio. FESEM and XRD measurements showed that the AC was amorphous. The prepared AC was effective in eliminating dibenzothiophene (DBT) from model fuel (200 ppm DBT/hexane) with a maximum performance 95.26 % at 40 °C for 1h using 0.35 g of the AC. The exhausted AC was regenerated and reutilized 4 times, and removal efficiency reached 88.23 % in the 4th cycle under ideal working conditions.

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.

Evaluation of stirring rate and pH on phenolic compounds recovery from palm kernel shell heavy phase bio-oil

This study aims to develop an efficient separation method for phenolic compounds derived from the heavy phase of bio-oil produced by the pyrolysis of palm kernel shell. Two variables were investigated during phenolic compound extraction using dichloromethane, i.e., stirring rate and pH of the solution. In both variables, the composition, yield, and distribution coefficient of the extracted phase were investigated. The results showed that the phenolic compounds' extraction favors high stirring rate and it obtained more results at more acidic conditions (lower pH). The best conditions for phenolic compounds were at 300 rpm of stirring rate and pH 4, which resulted in 77.88 % of yield and a 1.13 distribution of coefficient for the total phenols. The findings of this research will contribute to the better separation of phenolic compounds in bio-oil for improving its fuel characteristics as well as producing value-added chemicals.

Insight into the thermodynamic and kinetic analysis of Tamarindus indica shell using thermogravimetric analysis

ABSTRACT The shells of Tamarindus indica could serve as a primary source of energy generation from biomass. This paper deals with non-isothermal thermogravimetric experiments conducted at heating rates of 5, 10, 15, and 20°C/min with temperatures ranging between 25°C and 700°C to evaluate the kinetic behavior and the thermodynamic properties of Tamarindus indica shell pyrolysis. Three iso-conversational models, Kissinger–Akahira–Sunose (KAS), Starink, and Flynn-Wall-Ozawa (FWO), were used to identify the activation energy (Ea), Enthalpy (ΔH), Entropy (ΔS), and Gibbs free energy (ΔG) of the Tamarindus indica shell biomass. The average activation energy when estimated using KAS, Starink, and FWO models was found to be 209.1, 209.3, and 207.5 kJ/mol with R2 values of 0.91, 0.91, and 0.92, respectively. The average ΔH, ΔS, and ΔG values using the KAS method were found to be 204.4 kJ/mol, 82.2 J/mol K, and 155.2 kJ/mol, respectively. The values of kinetic and thermodynamic triplets indicate that the reaction is non-spontaneous. The findings of this present study reveal that there is an opportunity for Tamarindus indica shells to be used as an alternative biomass fuel due to their eco-friendly nature and ideal properties.

Hydrothermal carbonization coupled with fast pyrolysis of almond shells: Valorization and production of valuable chemicals

In this study, it was found that hydrothermal carbonization (HTC) can be an effective method for almond shell (AS) valorization. The severity of HTC treatment had a significant effect on hydrochar yields, with higher severity promoting carbonization but reducing yields. Furthermore, the work found that HTC treatment effectively demineralized biomass samples by removing inorganic material that could catalyze carbonization. As residence time or temperature increased, the amount of carbon increased, while the amount of oxygen decreased. An acceleration in thermal degradation was detected for hydrochars after pretreating for 4 h. The hydrochars showed they had a higher volatile content than untreated biomass, making them potentially useful for producing quality bio-oil through fast pyrolysis. Finally, HTC treatment led to the production of valuable chemicals such as guaiacol and syringol. For syringol production, HTC residence time had more effect than HTC temperature. However, high HTC temperatures benefited levoglucosan production. Overall, the results demonstrated the potential for HTC treatment to be an effective method for valorizing agricultural waste, offering the possibility of producing valuable chemicals.

The effects of apricot kernel shell nanobiochar on mechanical properties of cement composites

Valorization of agricultural wastes is important both economically and environmentally. This study aimed to investigate the use of biochar as a filler to improve the mechanical properties of mortar and to help sequestrate CO2. The biochar was produced by pyrolysis of apricot kernel shell at 500 °C. Nanobiochar particles with dimensions less than 500 nm were obtained by high-energy ball milling process. Scanning electron microscope was used for determining the morphology of nanobiochar. The nanobiochar at different volume percentages [0.00-0.04-0.06-0.08-0.12-0.15%] was added to mortar. The mortar was casted into 40x40x160 mm molds. After water curing at 20°C for 28 days, compressive strength and flexural strength tests were performed. The mixture containing 0.04% nanobiochar by volume had an increase in flexural and compressive strengths by 5% and 15% respectively, while its fracture energies for flexure and compression increased by 98% and 38% respectively compared to the reference mortar. Furthermore, the mixture having 0.12% volume had an increase in flexural and compressive strengths by 32% and 11%, respectively, while the increase in fracture energies for flexure and compression was 52% and 25%, respectively, compared to the reference mortar. The mechanisms of nanobiochar effect on flow, strength, and fracture energy were enlightened. The nanobiochars bridge the cracks, divert the cracks, act as hydration nucleation sites, enhance the matrix by its porous structure, and developed internal curing that led to increase in strength and fracture energy. This study suggests that the biochar produced from the apricot kernel shell has the potential to be used as a carbon sequestering mixture to improve performance of mortar and thereby utilizing waste as a construction material, contributing to the economy and environment.

High-efficiency catalytic pyrolysis of palm kernel shells over Ni2P/nitrogen-doped activated carbon catalysts

Catalytic pyrolysis is a cost-effective technology for high-quality biofuel production. Biomass is converted to bio-oil by a thermal process in the presence of a catalyst. Catalyst development influences the reaction-pathway control to form a specific product. Here, the catalytic pyrolysis of palm kernel shells was investigated on melamine-doped activated-carbon-supported Ni2P. Different amounts of melamine (25–100 wt% support) were loaded on activated carbon by impregnation and carbonization, while the Ni2P catalyst was fabricated by the co-impregnation of nickel nitrate and ammonium hydrogen phosphate. The interaction between nitrogen-containing functional groups on the carbon surface and Ni2P caused a uniform dispersion of small-sized crystalline Ni2P particles on the activated-carbon surface, reduced from 28.91 nm to 10.85 nm, as shown by transmission electron microscopy analysis. The Ni2P/CN catalyst exhibited high oxygen removal and alkylphenol selectivity (more than 63%) in the liquid product at 350 °C under atmospheric pressure. Therefore, the Ni2P/CN catalyst described here exhibits good potential for high-selectivity catalytic pyrolysis of biomass to produce phenolic compounds, which have wide application in monomers and fuel additives.

Pyrolysis of Rice husk, Coconut shell, and Cladophora glomerata algae and application of the produced biochars as support for cobalt catalyst in Fischer–Tropsch synthesis

The performance of bio chars prepared from Rice husk, Coconut shell, and Cladophora glomerata algae as Fischer–Tropsch synthesis (FTS) cobalt catalyst support is investigated. The biochars are synthesized through the pyrolysis process. The three substrates were activated precisely at a specific temperature and time. 15 wt% cobalt catalysts were prepared by impregnation method. The physicochemical properties of catalysts were assessed using different techniques. The activity and selectivity of catalysts were studied in a fixed bed micro reactor at 220 °C, H2/CO ratio of 2, feed flow rate of 60 mL/min, 2 MP pressure and 14–16 h reduction on 400 °C. The catalytic performance of biochars supported cobalt catalysts was evaluated and compared with a γ-Alumina supported industrial catalyst. The modified algae biochar supported cobalt catalyst showed the highest FTS rate of 0.345 g HC/(g cat. h) and 67% CO conversion. While, C5+ liquid hydrocarbons selectivity showed a slight decrease.

Wet synthesis, characterization of goethite nanoparticles and its application in catalytic pyrolysis of palm kernel shell in TGA

Catalytic pyrolysis of biomass is a suitable means of obtaining high-yield bio-oil with reduced activation energy and char content. Goethite nanoparticles were synthesized via coprecipitation of FeCl2.4H2O and NaHCO3. TGA purged with N2 was used to study goethite’s catalytic effect on the thermal degradation of PKS. The obtained particles were characterized via instrumental analysis using BET, TEM, SEAD, and XRD gave multipoint SA of 309 m2/g & 0.276 cc/g; 18.33 nm; rings occurring at (101), (111), (021); and crystallinity of 51.51% with average size of 9.16 nm respectively. Their morphology was circular and needle-like shape. Its average crystallite size was 9.16 nm with a crystallinity of 51.51%. The 62.10% Fe in goethite was a suitable factor for its application as a catalyst in the thermal decomposition of PKS. The average Ea for uncatalyzed PKS were 53.45, 44.95, 47.09, 49.05 and 70.63 kJ/mol for order n =1, 0.30, 0.50, 0.67 and 2.00 respectively at the α of 0.2 while the average Ea for catalyzed PKS were 19.17, -17.70, 10.27, 12.64 and 52.69 kJ/mol for same order sequence at α of 0.71 using Coats–Redfern kinetics model. The goethite nanoparticles reduced Ea with higher α due to its special physicochemical properties.

Characterization of Cashew Nut Shell Pyrolysis Liquid: As a Source of Sustainable Energy and a Precursor in many Chemical Industries

20 g cashew nut shell (CNS) was pyrolyzed in a fixed bed pyrolysis reactor at a temperature of 700 °C, heating rate of 100 °C/min, and time of 45 minutes. The cashew nut shell liquid (CNSL) obtained was 61.3 %. Proximate and ultimate analyses, viscosity (cp), density (g/ml), pH, FT-IR, and GC-MS were carried out on the liquid. The results from the GC-MS and FT-IR analyses showed that the liquid consist mainly of aliphatic and aromatic hydrocarbons. The GC-MS analysis showed the different compounds present in this liquid and their relative abundance. From analyses, the liquid had an ash content of 0.06 %, sulphur content of 0.30 %, density of 0.992 g/ml, and a pH of 4.3.

Initial Ignition Time and Calorific Value Enhancement of Briquette with Added Pine Resin

The increasing demand for clean energy requires considerable effort to find alternative energy sources, such as briquettes. This research aims to develop a charcoal briquette with added pine resin (API) that has excellent combustion speed and distinctive aroma. Briquettes are composed of charcoal, pine resin (concentration: 0%–30%), and starch (up to 7%). They are produced in several stages, including coconut shell pyrolysis in conventional combustion, to obtain charcoal for the briquette precursor. Briquette compaction is conducted by mixing and densifying the charcoal, pine resin, and starch using a hydraulic press for 3 min. The hydraulic press has a total surface area and diameter of 57.7 cm2 and 3.5 cm, respectively. The briquettes are dried at different temperatures, reaching 70°C for 24 h. The study results show that the briquettes have a thickness and diameter of up to 2 and 3.5 cm, respectively; moisture of 2.18%–2.62%; ash of 11.61%–13.98%; volatile matter of 27.15%–51.74%; and fixed carbon content of 40.24%–59.46%. The compressive strength of the briquettes is 186–540 kg/cm2. Their calorific value is 5,338–6,120 kcal/kg, combusting at a high speed of 0.15–0.40 s. The methoxy naphthalene, phenol, benzopyrrole, and lauryl alcohol; ocimene, valencene, and cembrene are found in the API. The API briquette has several chemical compounds, such as musk ambrette, ocimene, sabinene, limonene, 1-(p-cumenyl) adamantane, butane, and propanal, which improve aroma, drug application, and fuel production. Accordingly, API briquettes have considerable potential as an alternative energy source and a health improvement product.

Influence of Oyster Shell Pyrolysis Temperature on Sediment Permeability and Remediation

Permeability is an important aspect of sediment remediation. It is well-known that oyster shells can be used for sediment remediation, however the influence of pyrolysis temperature on sediment permeability remains unknown. In this study, we examined sediment permeability and remediation using crushed oyster shells of less than 5 mm in size that were pyrolyzed at 350 °C (POS350) and 600 °C (POS600) for six hours. Based on the results of the variable head permeability test, POS600 has greater sediment permeability than POS350. In addition, POS600 has greater than POS350 to reduce dissolved inorganic nitrogen (DIN; NH3-N, NO2-N, and NO3-N) and phosphate (PO4-P) from organically enriched sediment because of its higher Ca2+ elution. In conclusion, pyrolysis of oyster shells at 600 °C is more effective than pyrolysis at 350 °C. This finding is true because the transformation of CaCO3 to CaO, which is the source of Ca2+, stimulates pore water flow. Based on these findings, it can be concluded that pyrolyzed oyster shells are beneficial for increasing sediment permeability, thereby helping in the remediation of sediments.

Potential use of residues from thermal conversion processes for CO2 capture

Economic development in many developing countries is leading to a significant increase in atmospheric CO2 in recent decades, exacerbating global climate change. One of the solutions being vigorously researched is the use of cheap and environmentally friendly CO2 adsorbents. In this study, solid residues from gasification of bagasse, and pyrolysis of macadamia nut shells were used for CO2 adsorption. The N2 adsorption/desorption results showed that the post-gasification residue was much more porous compared to the post-pyrolysis residue. The CO2 adsorption experiments were carried out in laboratory conditions (100 % CO2, 25 °C) and flue gas conditions (15 % CO2, 40 °C). The bagasse residue achieved a high and stable CO2 adsorption value at 2.3 mmol/g, 2.5 times more than that of macadamia nut shells residue. This result showed that residues from thermal conversion processes could be re-used as cheap and environmentally friendly materials for CO2 capture.

Route of biofuel production from macadamia nut shells: effect of parameters on the particles mixing index in fluidized beds

Pyrolysis of macadamia nut shells (MNS) in a fluidized bed reactor has excellent potential to produce bio-oil. High heat transfer rates and uniform temperature in the fluidized bed can be achieved due to effective gas-solid contact in the reactor. However, binary mixtures can lead to the segregation of particles, which negatively affects heat and mass transfer in such a reactor. Therefore, a 2³ statistical experimental design was used to assess the effects of parameters (i.e., air velocity, particle diameter ratio, and mass fraction of MNS) on the mixing index of the bed of MNS and sand. Among the analyzed factors, only DMNS/DS and V/VMF influenced the mixing index (Im) within a confidence interval of 95%. Based on statistical data analysis, an air velocity 20% above the minimum fluidization and particle diameter ratio (DMNS/DS) smaller than 3 results in uniform particle mixing in the bed (i.e., reaching ideal mixing index values). Moreover, the experimental results indicate that fluidized be used for biofuel production from Macadamia nut Shells.

Pengaruh Suhu dan Waktu Pirolisis terhadap Karakteristik Arang dari Tempurung Kelapa

The increased production of coconut has increased by the shell produced, even though this coconut shell has lignin content of 33.30% so it has the potential to be converted into charcoal through the pyrolysis process. Pyrolysis is a thermal decomposition process that occurs without air or with little air to convert biomass into charcoal. Coconut shell charcoal can be used for coal co-firing in developing new and renewable energy. This study aimed to obtain the best pyrolysis temperature and time in the manufacture of high-calorific value coconut shell charcoal in accordance with SNI 06-4369-1996. Coconut shell pyrolysis was carried out at temperatures of 350 °C, 450 °C and 550 °C and pyrolysis times of 2 hours, 3 hours and 4 hours. The results showed that charcoal with the highest calorific value was produced at a temperature of 450 °C and a pyrolysis time of 3 hours. The resulting charcoal had calorific value of 7,750.96 cal/g, yield of 30.10%, and contained 2.75% water, 2.70% ash and 9.50% volatile matter.

Value-added biochar production from microwave pyrolysis of peanut shell

Abstract In order to seek efficient resource utilization, the carbonization of agricultural and forestry wastes through microwave pyrolysis technology is an important research hotspot to develop value-added products. The main objective is to produce value-added biochar through microwave pyrolysis of peanut shell in this study. The product yields, functional groups, and biochar HHVs caused by pyrolysis temperature (400, 450, 500, 550, and 600 °C), microwave power (350, 450, 550, 650, and 750 W), and residence time (10, 20, 30, 40, and 50 min) were investigated, and the energy recovery efficiencies were evaluated. It was obtained that the biochar yield declined monotonously within the range of 45.3–86.0 wt% with the enhancement of pyrolysis temperature, microwave power, or residence time. The pyrolysis temperature of 400 °C, microwave power of 350 W, and residence time of 10 min generated the maximum biochar yield (86.0 wt%). The value-added biochar was obtained with high HHV (20.15–31.02 MJ/kg) and abundant oxygen-contained functional groups (C–O bonds and C=O bonds). The maximum energy recovery efficiency during the whole process reached 97.96%. The results indicated that the peanut shell could reach high biochar yield through microwave pyrolysis, and potentially be transformed into value-added products with high energy recovery efficiency.

Mass transfer study of phenolic compound liquid-liquid extraction process from bio-oil of coffee shell pyrolysis product

Coffee shells are one of the potential renewable materials used in the pyrolysis process to produce bio-oil. However, the amount of phenolic compounds, which is roughly 36.74%, is one of the primary drawbacks of using coffee shell bio-oil as a fuel source. Only a little amount of research has been done on the mass transfer modeling and phenomena of phenol extraction from coffee shell bio-oil. The objectives of this study are to identify the best extraction circumstances, ascertain the empirical correlation of total mass transfer, and produce the empirical correlation of Sherwood number, which can be used to characterize the role of variables in this mass transfer process. The ratio of impeller diameter to tank diameter and the Sherwood number, as well as Reynolds, Schmidt, Weber, dispersed phase holdup, were studied as dimensionless numbers. This study used liquid–liquid extraction process at the temperature of 50 ℃, with chloroform–methanol 80% as a solvent with ratio of 2:1 v/v and use bio-oil to solvent ratio of 1:1 v/v. The extraction time has an interval of 30 min (20, 50, 80, 110 min), with varied impeller diameter (3.5 cm and 4 cm), vessels diameter (9 cm and 10 cm) and mixing speed (250 rpm, 300 rpm, 350 rpm). According to the findings, the greatest phenol yield was obtained at impeller diameter 3.5 cm, tank diameter 9 cm, and mixing speed 300 rpm, with a distribution coefficient of 0.848. The results demonstrate that the maximum overall mass transfer coefficient is 4.096 × 10-4 m/s and that the liquid diffusivity is 1.7965 × 10-9 m2/s. The equation model from this study could be applied to a liquid–liquid extraction process that is scaled up to extract more phenolic compounds from the the produced bio-oil.

Novel solid-state calcium carbide synthesis from calcium oxide and walnut shell char by in-situ induction heating

Calcium carbide (CaC2) is a platform chemical to synthesize many polymers. It has been produced in industry by reacting CaO with coal derived coke in electrical arc furnaces for more than a century at temperatures higher than 2000 °C to ensure the formation of CaC2-CaO eutectics at the furnace bottom, which completes the electrical arc circuit but inevitably limits the molten product discharge to a periodical mode. Here we report new observations that under electromagnetic induction of 400 kHz, walnut shell char can be rapidly heated to high temperatures and so be the pellets containing CaO and walnut shell char (CaO-C) prepared from pyrolysis of calcium hydroxide and walnut shell. For the induction heating (IH) of the char to take place the threshold temperature of pyrolysis is around 800 °C and threshold CaO-C pellet size is Φ12 × 12 mm. The pellets with the stoichiometric C/Ca molar ratio of 3 or higher yield solid-state CaC2 under IH. A higher C/Ca ratio results in a higher heating rate, a higher maximum temperature, and a higher CaC2 yield. A CaC2 yield (CaO based) of 99.6% is obtained in 10 min for pellets with a C/Ca ratio of 10, a size of Φ15 × 15 mm and the maximum pellet temperature of higher than 1726 °C.