Pyrolysis Kinetic Analysis Research Articles

Pyrolysis kinetic, thermodynamic and product analysis of different leguminous biomasses by Kissinger-Akahira-Sunose and pyrolysis-gas chromatography-mass spectrometry

To ascertain the potential of various leguminous biomass such as L. leucocephala, C. proliferus, P. alba and S. sesban, both energetic and a source of high added value products, the pyrolytic behaviour was studied at different heating rates by using the analytical method of thermogravimetric (TG), isoconversional method of Kissinger-Akahira-Sunose (KAS), determination of some thermodynamic parameters and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). It was concluded that biomass such as L. leucocephala or C. proliferus are more suitable for pyrolysis since less energy is required to degrade them, more evident in the final stages of degradation in which P. alba and S. sesban present very high activation energies calculated by KAS. All leguminous biomass produced volatile compounds with high phenol content at the peak of maximum degradation of hemicellulose, most of the heavy derivates are derived from lignin, such as ferulaldehyde or methoxyeugenol, because sufficient energy has not yet been provided to break down the structure. At this peak it can see some furans and saccharides in the case of C. proliferus since it has a higher C5 content in its composition. A wide range of compounds were detected at the peak of maximum degradation of cellulose, L. leucocephala and C. proliferus produce more short-chain compounds that give rise to bio-oils whereas, S. sesban and especially P. alba, in addition, produce a quantity of high added value of saccharides such as levoglucosan and d-allose (4.73% and 13.94%, respectively).

Study on the co-pyrolysis of oil shale and corn stalk: Pyrolysis characteristics, kinetic and gaseous product analysis

Co-pyrolysis of oil shale and biomass can promote thermal decomposition and improve product quality because of the interaction. Therefore, the co-pyrolysis characteristics of oil shale (OS) and corn stalk (CS) were investigated by the combination of TG-FTIR-MS study. TG/DTG results showed that the decomposition of cellulose was promoted during co-pyrolysis, and the decomposition temperature of OS was advanced, while the decomposition rate decreased. Kinetic analysis showed that the lowest apparent activation energy occurred at a CS blending ratio of 50%. MS and FTIR showed that co-pyrolysis impeded the release of oxygen-containing gases, especially H2O and CO2 after 400 °C. The oxygen transfer mechanism is also applicable to OS and CS co-pyrolysis, which means the intermediate formed by the combination of alkali metal released from CS and C-O in OS has catalytic effect after chemisorbing H2O and CO2, leading to easier bond breaks in OS and re-release of partial H2O and CO2.

Pyrolysis characteristics, kinetic, and thermodynamic analysis of camel dung, date stone, and their blend using thermogravimetric analysis

Pyrolysis characteristics, kinetic, and thermodynamic analysis of camel dung, date stone, and their blend using thermogravimetric analysis

Study on the Pyrolysis Behaviors of Urea-Formaldehyde Resin and Rice Straw Mixed Pellets

In order to study the effect of biomass on the pyrolysis characteristics of urea-formaldehyde resin, the thermogravimetric experiments were carried out respectively using urea-formaldehyde resin (UF), rice straw (RS), and their mixed pellets with different proportions. The pyrolysis kinetics analysis was conducted. The results showed that the pyrolysis process of UF resin and mixed pellets could be divided into three stages: the drying and dehydration of the material, the rapid decomposition of volatile matter, and residue decomposition. The reaction order of UF resin and mixed pellets was discussed using the Coats–Redfern method, the activation energy of UF resin was 54.27 kJ/mol, and this value decreased with the addition of rice straw. As the mass ratio of UF resin to rice straw was 3:1, the activation energy achieved the lowest value, which means that the addition of rice straw was beneficial to the pyrolysis process of UF. In the process of pellet preparation, the falling strength and compressive strength of UF resin pellets can be improved by adding an appropriate proportion of rice straw. In this test, the yield of pyrolytic carbon reached the highest value of 23.93%, as the mass ratio of UF resin to rice straw was 3:2. When the mass ratio was 4:1, the highest liquid product yield of 43.21% was achieved.

Pyrolysis characteristics and kinetic analysis of tobacco stem pretreated with different solvents

Pyrolysis characteristics and kinetic analysis of tobacco stem pretreated with different solvents

The Pyrolysis Characteristics and Kinetic Analysis of Maoming Oil Shale Heated by Transition Metal Salt Assisted Steam

The Pyrolysis Characteristics and Kinetic Analysis of Maoming Oil Shale Heated by Transition Metal Salt Assisted Steam

Composition and structure characteristics of soluble organic matter from Naomaohu lignite by sequential extraction and thermal conversion performance of the corresponding residue

Carbon disulfide (CDS), methanol, acetone and isometric carbon disulfide/acetone mixture (IMCDSAM) were used as solvents to sequentially extract Naomaohu lignite (NL) via ultrasonic-assisted extraction to obtain extracts (E1–E4) and final extraction residue (ER). Composition and structure of E1–E4 were analyzed by GC-MS. It is found that the main compounds in E1 are alkanes, aromatics, alcohols and esters. Alkanes, alcohols and esters are the main compounds in E2. Alcohols, phenolics and esters are the main components in E3, and esters are mainly phthalic diester compounds. Affected by synergistic effect of the two solvents CDS and acetone, the relative content of alkenes in E4 is relatively high. FT-IR was used to characterize functional groups in NL, E1–E4 and ER. The results show that the ultrasonic extraction process only extracts free small compounds from macromolecular skeleton of the NL and some other molecules, which connect the macromolecular skeleton by weak covalent bonds, and the process does not destroy the macromolecular skeleton structure. In addition, peak fitting results from FT-IR show that types of infrared absorption peaks in ER do not change after ultrasonic extraction, while intensity of the peaks varies. TG-DTG profiles of NL and ER indicate that after ultrasonic extraction weight loss of NL increases from 47.09% to 51.04%, and peak of the maximum weight loss rate is advanced from 450 to 430°C. Pyrolysis kinetic analysis of NL and ER based on Coats-Redfern model show that after ultrasonic extraction activation energy of ER in rapid pyrolysis stage is lower than that of NL, and the pyrolysis process is easier to proceed.

Pyrolysis Characteristics and Kinetics Analysis of Oil Sludge with CaO Additive

In the process of exploitation, transportation and refining of high-sulfur crude oil, a large number of oil sludge (OS) with high sulfur content is produced. Pyrolysis has been proved to be an effective method for OS disposal, but for solid waste with high sulfur content, lots of sulfur-containing gases will be released during thermal disposal. The addition of calcium oxide [1] in pyrolysis process is an economical and effective way to capture sulfur-containing gases. In order to understand the pyrolysis process of OS with CaO, a thermogravimetric analyzer was used to conduct pyrolysis experiments of OS with different Ca/S molar ratios (0, 1, 2, and 3) at different heating rates (10, 20, 30 and 40 °C/min). The results showed that with the increase of CaO addition the derivative thermogravimetric curves (DTG curves) showed a gentle trend. In addition, new weight loss peaks were occurred at 700∼900°C and after 1100°C, which were the decomposition of calcium carbonate and calcium sulfate, respectively. The kinetic parameters were solved by Friedman, FWO, and Starink methods, and the results were similar, with an average activation energies (E) value of 214 kJ/mol. The change trend of the activation energy followed by an increase and then a decrease corresponding to the change of energy demand for the reaction. The calculated average values of ΔH, ΔG and ΔS were about 207 kJ/mol, 447 kJ/mol and -0.3250 kJ/mol respectively. When the conversion rate was 0.5, the thermodynamic parameters reached their maximum values.

Pyrolysis of torrefied rice straw from gas-pressurized and oxidative torrefaction: Pyrolysis kinetic analysis and the properties of biochars

In this work, the pyrolysis of torrefied rice straw (RS) from oxidative/non-oxidative torrefaction were carried out, in order to investigate the effects of torrefaction pressure such as rotary tube reactor (AP) and gas-pressurized autoclave (GP) on the pyrolysis behavior and biochars’ properties. The pyrolysis kinetic parameters were determined using four model-free (Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Friedman and Kissinger) methods. The results revealed that the pyrolysis kinetics of torrefied RS were significantly influenced by the torrefaction pressure. The experimental results were best fit by the FWO method, and the Eα values obtained by the KAS and Friedman methods were similar to that obtained by the FWO method. The pyrolysis of GP-torrefied RS was safer and more stable than that of AP-torrefied RS. The parameters of AP-180 °C sample calculated by the Kissinger method were highly correlated (R2 > 0.9), although it was not applicable for the AP/GP-270 °C samples. The biochars derived from AP-torrefied RS had a higher specific surface area and higher O/C and (O + N)/C ratios than those derived from GP-torrefied RS. Adsorption capacity of the biochar derived from AP-torrefied RS (P-A3, 68.97 mg/g) for tetracycline was higher than that of the biochar derived from GP-torrefied RS (P-G3, 39.68 mg/g).

Pyrolysis performance and kinetic analysis of oily sludge

Pyrolysis performance and kinetic analysis of oily sludge

Direct liquefaction performance of sub-bituminous coal from Hefeng by solid super acids and pyrolysis kinetic analysis of the corresponding residue

Highly active, recyclable, and reusable supported super-acid catalyst is of great significance for improving coal liquefaction performance and liquefaction conditions and realizing comprehensive utilization of coal resources. Solid super-acid catalysts were prepared by impregnation method with trifluoromethanesulfonic acid (TFMSA) supported on different carriers (ZrO2, Al2O3, SiO2, and ZSM-5). Hefeng sub-bituminous coal (HFSB) was used as raw material to investigate the liquefaction effect of the catalysts. Composition, structure, acidity property of the catalysts were analyzed by EDS, XRD, and NH3-TPD methods, and direct coal liquefaction performance of the catalysts was performed, and TG-DTG characterization was used to evaluate the pyrolysis behavior of the liquefaction residue. Results showed that activity of the four supported solid super-acid catalysts was followed by TFMSA/ZrO2, TFMSA/ZSM-5, TFMSA/Al2O3, and TFMSA/SiO2, with coal conversions of 84.20 %, 78.40 %, 76.67 % and 73.23 %, and oil yields of 67.16 %, 62.53 %, 61.15 %, and 58.41 %, respectively. The Coast-Redfern method was used to analyze the pyrolysis kinetics of the four coal liquefaction residues (R-ZrO2, R-ZSM-5, R-Al2O3, and R-SiO2). Results presented that, in low temperature range (200−530 ℃), except R-SiO2, the pyrolysis process of residues conforms to the third-order reaction. And in high temperature range (530−850 ℃), the four-order reaction is more suitable for the four residues. The pyrolysis activation energy of R-ZrO2 is lower at low temperature region (16.822 kJ/mol), while R-Al2O3 presents lower activation energy at high temperature range (45.494 kJ/ mol).

Analysis of Pyrolysis Characteristics and Kinetics of Cigar Tobacco and Flue-Cured Tobacco by TG-FTIR

Summary Investigation of the detailed pyrolysis characteristics of tobacco raw materials is important for the understanding of product design and consumption. In this work, pyrolysis characteristics and kinetic models of cigar filler tobacco (CFT), cigar wrapper tobacco (CWT), and flue-cured tobacco (FCT) were investigated by using a thermogravimetric analyzer coupled with Fourier-transform infrared spectroscopy (TG-FTIR). The pyrolysis of different tobacco samples could be divided into four stages based on the derivative thermogravimetric analysis (DTG) curves. Flue-cured tobacco underwent a marked decomposition process at lower temperatures (about 200 °C), while the thermal decomposition of cigar tobacco occurs at higher temperatures. During the pyrolysis process, evolved gases including H2O, CO2, CH4, CO, carbonyls, alcohols, phenols and aromatic compounds were detected by FTIR. CWT released more CO2 than CFT, while the amount of CO2, CH4, CO and aromatic compounds released by flue-cured tobacco was lower than that of cigar tobacco. The pyrolysis kinetics of tobacco leaves were further analyzed and compared through the isoconversional FWO (Flynn-Wall-Ozawa) and KAS (Kissinger-Akahira-Sunose) methods. The activation energy of FCT (from 100.1 kJ mol−1 to 192.1 kJ mol−1) was lower than that of CFT (from 207.36 kJ mol−1 to 319.28 kJ mol−1) and CWT (from 160.40 kJ mol−1 to 260.45 kJ mol−1). The thermal decomposition kinetics of different tobaccos were analyzed by Málek and Coats-Redfern methods.

Physicochemical characterization and pyrolysis kinetic analysis of Moutai-flavored dried distiller’s grains towards its thermochemical conversion for potential applications

The physicochemical properties of dried distiller’s grains (DDGs) were measured and the pyrolysis kinetics analysis was experimentally investigated by the non-isothermal thermogravimetric analysis (TGA) at four heating rates of 10, 20, 30 and 40 K min−1. The results of proximate and elemental analysis showed that DDGs contained relatively high contents of volatile organic components (VOCs, 89.4 wt.%) and carbon (47.0 wt.%), and a higher value of heat content (20.4 MJ kg−1), compared with some other typical agricultural residues feedstocks. The pyrolysis kinetics of DDGs sample were analyzed using the Friedman isoconversional method. The obtained effective activation energies vary with the degree of conversion: 151.2-176.3 kJ mol−1 (α: 0.05−0.10, T: 383–506 K), 176.3-206.4 kJ mol−1 (α: 0.10−0.60, T: 506–653 K), 206.4-320.5 kJ mol−1 (α: 0.60−0.95, T: > 653 K), which correspond to the thermal decomposition of hemicellulose, cellulose and part of lignin, and remaining lignin. And the decomposition temperatures of DDGs components shift to lower temperature, compared with those of typical lignocellulosic biomass, which is caused by the presence of high activity degraded enzymes during brewing process. The physicochemical properties and pyrolysis kinetic results have shown that DDGs has great thermochemical conversion potential for bioenergy. We anticipate these findings will contribute to the industrial application of DDGs pyrolysis to produce biofuel or high-value chemicals and materials.

Pyrolysis Behaviour and Kinetic Analysis of Food Waste Sludge Cake

Concerns regarding energy security are raised due to the conventional fossil fuel depletion, which drives the need of diversifying fuel sources for power generation. Sewage sludge, which is a waste product from the wastewater treatment plant, contains energy that could be retrieved and reused. Typically, these sludge are treated as a form of schedule waste and disposed of in a landfill. In this work, the valorisation potential of sludge cake to produce higher-value products was studied through thermogravimetric analysis....It has been demonstrated through this study that the sludge cake from food processing industries is a promising feedstock pyrolysis to yield bio-products of higher values.

Microwave-assisted catalytic pyrolysis of apple wood to produce biochar: Co-pyrolysis behavior, pyrolysis kinetics analysis and evaluation of microbial carriers

This studyinvestigated the behavior and kinetics of co-pyrolysis of apple wood (AW)with H3PO4and K3PO4as catalysts under microwaveto prepare biochar as microbialabsorbent. The kinetic studies indicate that the co-pyrolysis of AW withH3PO4orK3PO4can effectively improve the pyrolysis efficiencyand enhance the biocharcharacteristicsby reducing ofthe activation energy of the pyrolysis reaction. The kinetic parameters indicate that the activation energy of the mixturesin the main pyrolysis stage is lower than that of a single AW, whichmeanthat the co-pyrolysis of AW withH3PO4orK3PO4shows excellent synergy. Biochar characterization showed that the yield of biochar reachedthe highest58.6% whenthe ratio(H3PO4/AW) is0.5. The adsorption results show that the bacteria SL-44 can be effectively loaded on the surface of the biochar, and the adsorption process is combined with Langmuir model and process can proceed spontaneously.

Pyrolysis characteristic and kinetic analysis of sewage sludge using model-free and master plots methods

The pyrolysis kinetics of two types of sewage sludge (municipal sludge and pharmaceutical sludge) were studied by thermogravimetry. The collected samples were pretreated and tested with nitrogen as carrier gas at different heating rates (10, 20, 30, and 40 °C/min) using a thermogravimetric analyzer. Model-free methods and master plots method were used to calculate the pyrolysis kinetic parameters of the samples. TG/DTG results showed that the thermal decomposition of the two types of sewage sludge may be divided into three stages (Dehydration, Decomposition, and Coking stage). The activation energies of the two kinds of sewage sludge were 366.58 KJ/mol (municipal sludge) and 268.36 KJ/mol (pharmaceutical sludge), respectively. The pyrolysis mechanism of two kinds of sewage sludge was discussed by the master plots method. The results showed that under a low conversion rate, the phase interface reaction model can better explain the pyrolysis mechanism of pharmaceutical sludge; under high conversion rate, the nucleation and growth model was more suitable. For municipal sludge, power law model was most suitable in the whole range. The pyrolysis characteristic of the samples was further studied. The results showed that the organic matter in sewage sludge can be decomposed into bio-oil and bio-gas at elevated temperatures and can be used as an attractive energy source.

A cost-effective strategy for metal recovery from waste printed circuit boards via crushing pretreatment combined with pyrolysis: Effects of particle size and pyrolysis temperature

The dramatic increase in global generation of e-wastes has become a great challenge for sustainable development, and strategies for efficient and environmental-friendly recycling and disposal of e-waste are of great demand. A cost-effective strategy of crushing pretreatment combined with pyrolysis to recover metals from waste printed circuit boards (WPCBs) has been developed. Effects of particle size and pyrolysis temperature on metal recovery were explored. The optimal combination of less energy consumption and higher metal recovery was obtained when the pretreated particle size was 4.0 cm and pyrolysis temperature was 330 °C. The Cu and Sn were recovered as zero-valent copper and tin-copper alloy with the recovery efficiency of 92.38 and 99.80 wt%, respectively. Brominated pollutants are easily controlled when pretreated particle size is larger than 2.0 cm and pyrolysis temperature is below 400 °C. Under the optimal crushing pretreatment and pyrolysis conditions, the bromine contents in the pyrolysis products of solid residues, liquid tar, and gas were 45.45 wt%, 38.70 wt%, and 15.85 wt%, respectively. The structure of WPCBs was destroyed at 275–525 °C due to decomposition of brominated epoxy resins (BERs), which could be accurately characterized by 8 dominating reactions through pyrolysis kinetics analysis. The main reactions took place at conversion of 0.14 and 0.15, corresponding to a pyrolysis temperature of 306–342 °C. Thus, the interlayer bonding force of WPCBs significantly decreased, contributing to effective separation of metals in WPCBs.

Pyrolysis Kinetic Analysis of Biomasses: Sugarcane Residue, Corn Cob, Napier Grass and their Mixture

Pyrolysis Kinetic Analysis of Biomasses: Sugarcane Residue, Corn Cob, Napier Grass and their Mixture

Characterization of Pyrolysis Products and Kinetic Analysis of Waste Jute Stick Biomass

Thermochemical process of biomass is being considered as a latest technique for the restoration of energy source and biochemical products. In this study, the influence of the different heating rates on pyrolysis behaviors and kinetic of jute stick were investigated to justify the waste jute stick biomass as a potential source of bioenergy. Pyrolysis experiments were carried out at four several heating rates of 10, 20, 30 and 40 °C/min, by utilizing the thermogravimetric analyzer (TG-DTA) and a fixed-bed pyrolysis reactor. Two different kinetic methods, Kissinger–Akahira–Sunose (KAS) and Ozawa–Flynn–Wall (OFW) were used to determine the distinct kinetic parameters. The experimental results showed that, the heating rates influenced significantly on the position of TG curve and maximum Tm peaks and highest decomposition rate of the jute stick biomass. Both the highest point of TG and the lowest point of Derivative thermogravimetry (DTG) curves were shifted towards the maximum temperature. However, the heating rates also influenced the products of pyrolysis yield, including bio-char, bio-oil and the non-condensable gases. The average values of activation energy were found to be 139.21 and 135.99 kJ/mol based on FWO and KAS models, respectively.

Thermal pyrolysis characteristics and kinetic analysis of nanofibrillated cellulose/graphene oxide composites

The fabrication process determines the microstructure and physical properties of material to some extent. In this study nanofibrillated cellulose /graphene oxide (NFC/GO) composites were fabricated by casting and evaporation methods, respectively. The microstructure and thermostability of the composites were investigated. The composites fabricated by the casting method had more uniform layered microstructure than those made by the evaporation method. The thermogravimetry analysis indicated that in the stage of 100 to 220 °C diffusion, the mechanisms of the Ginstling-Brounstein equation (D4) and the one-way transport equation (D1) can be regarded as the most suitable thermal pyrolysis reaction models for the composites made by the casting method and the evaporation method, respectively. However, in the stage of 220 to 380 °C, the two types of composites showed totally different thermal pyrolysis mechanisms. The results manifested that forming methods could indeed affect the microstructure and thermal degradation process of composites.