Thermal Decomposition Characteristics Research Articles

Thermal stability and exothermic behaviour of imidazole ionic liquids with different anion types under oxidising and inert atmospheres

Ionic liquids (ILs), as a type of salt that is liquid at room temperature, break the entrenched views on salt when it was proved that some of them could be ignited. In this research, an innovative method was used to evaluate the thermal stability of such special salts and speculated their ignition mechanism based upon gas analysis. Four typical representative imidazole ILs (BMIMBF4, BMIMDCN, BMIMNO3, and BMIMOAc) were selected, and their thermal decomposition characteristics and thermal effect were obtained by simultaneous thermogravimetric analyser (STA) and differential scanning calorimetry (DSC), respectively. Furthermore, their decomposition products were investigated by thermogravimetry coupled with Fourier-transform infrared spectroscopy (TG-FTIR). It is noteworthy that they behaved diversely in DSC experiments and exhibited a radically different thermal effect in their decomposition. In addition, there exists positive feedback in the mechanism of the exothermic phenomenon of selected ILs in the air. Nevertheless, TG curves of four selected ILs were almost the same under air or nitrogen conditions. Series TG-FTIR experiments confirmed that the initial decomposition products of BMIMBF4 and BMIMDCN under air or nitrogen are extremely different. The decomposition products of BMIMNO3 and BMIMOAc in the air atmosphere have more oxidative products than nitrogen. The results denoted that the thermal decomposition mechanism of the four selected ILs in the air were the same as under nitrogen. The reducibility of the decomposition products induced the peculiar thermal effects of these imidazole ILs under the different gas environments. This study was innovative in researching the thermal effect and mechanism of imidazole ILs’ decomposition and provided certain safety guidance for the process safety and loss prevention of imidazole ILs.

Effect of oxygen concentration and external radiation on the thermal decomposition and combustion characteristics of electric wire

Effect of oxygen concentration and external radiation on the thermal decomposition and combustion characteristics of electric wire

Pyrolysis of Vegetable Oil Soapstock in Fluidized Bed: Characteristics of Thermal Decomposition and Analysis of Pyrolysis Products

This study investigated the effect of temperature on pyrolysis of soapstock in a fluidized bed reactor, and the characterization of soapstock chars (SCs) and pyrolysis oils (POs) were analyzed. TGA (Thermogravimetric-analysis), TG-FTIR (Fourier-transform-infrared-spectrometry), TG-MS (Mass-spectrometry) were employed to investigate characteristics of SS pyrolysis. Experimental results indicated that the yield of SC decreased with increasing temperature. PO yield reached the maximum of 21.05 wt% at 600 °C and the yield of non-condensable gas varied with temperatures. The content of carbon, hydrogen and nitrogen distributed in the SC decreased with the increasing temperature, and sulfur tended to be retained in SC during pyrolysis with the distribution ratio of 0.55-0.62. Ketones, alcohols and hydrocarbons were the dominate substances in PO, and higher temperature promoted the production of short-chain alkanes and the conversion of alkenes to benzene derivatives. SS pyrolysis can be divided into three stages. Decomposition and transformation of organics mainly occurred at stage II and Ca2+ played a catalytic role for decarboxylation at stage III. Decarboxylation was the main deoxygenation pathway. This study provided a theoretical basis for the application of soapstock thermochemical treatment. It is of great significance for the quality improvement of PO and pollution control for pyrolysis processes.

Study on the inhibitory property and mechanism of inert powder on dust explosion flame of oil shale

In order to study the inhibitory property and mechanism of inert powder on dust explosion flame in oil shale, five common inert powder and two types of oil shale were selected for the explosion flame inhibition experiment by using the dust explosion flame propagation test system. First, a high-speed camera was used to record the flame image during the inhibition of oil shale dust explosion by inert powder, and the differences in explosion flame length, minimum inerting ratio and flame morphology and structure were analyzed in detail. Then, the thermal decomposition and endothermic characteristics of the inert powder were tested by Thermogravimetric-Differential Scanning Calorimetry (TG-DSC), and the TG-DTG-DSC thermal characteristic curve of the inert powder was analyzed. Combined with the analysis of the inhibition effect of the inert powder in the preheating zone and the combustion flame zone, the inhibitory property and the mechanism of the inert powder on the oil shale dust explosion flame were systematically studied. The research results show that the inhibitory performance of inert powder to the explosion flame of two kinds of oil shale dust is ranked as: ABC dry powder ＞Al(OH)3＞Mg(OH)2＞NaHCO3＞rock powder, and their explosion inhibition performance against Huadian oil shale (HDOS) is better than that of Longkou oil shale (LKOS). In this paper, the physical model of the inhibition mechanism of inert powder on the explosion flame of oil shale dust is established and the inhibition mechanism is analyzed. Through the mechanism analysis, it is shown that the high-efficiency explosive inhibition powder should have good thermal stability (decomposition temperature around 200−400 ℃), high heat absorption, and the decomposition of intermediate products can combine with the combustion reactive radical to play a chemical inhibition effect. The research results can provide theoretical basis and basis for the design of explosion inhibition of oil shale dust and the development of explosive inhibition powder.

Characteristics and modeling kinetics of oil palm frond petiole pyrolysis using thermogravimetric analyzer

As one of the largest palm oil-producing countries globally, Indonesia produces abundant oil palm biomass; indeed, it brings large oil palm frond petiole (OPFP). OPFP is one of the oil palm biomass that can be converted into an energy source. This research focuses on analyzing thermal decomposition characteristics and pyrolysis kinetics of OPFP using thermogravimetric analysis (TGA). The results showed that the thermal decomposition of pyrolysis was divided into three steps, including the evaporation stage of moisture content, the releasing of volatile compounds and organic matter, and the final stage of lignin and tar decomposition. Both the activation energy and the pre-exponential factors were analyzed with the Coats-Redfern method in step II active pyrolysis zone are 80.56 kJ/mol and 7.21/min, respectively, as shown in the Chemical Reaction Order F1.5 model with the accuracy of a correlation coefficient of 0.99. These results provided the fundamental data useful for properly designing the reactor system for industrial purposes.

Faecal sludge pyrolysis: Understanding the relationships between organic composition and thermal decomposition

Sludge treatment is an integral part of faecal sludge management in non-sewered sanitation settings. Development of pyrolysis as a suitable sludge treatment method requires thorough knowledge about the properties and thermal decomposition mechanisms of the feedstock. This study aimed to improve the current lack of understanding concerning relevant sludge properties and their influence on the thermal decomposition characteristics. Major organic compounds (hemicellulose, cellulose, lignin, protein, oil and grease, other carbohydrates) were quantified in 30 faecal sludge samples taken from different sanitation technologies, providing the most comprehensive organic faecal sludge data set to date. This information was used to predict the sludge properties crucial to pyrolysis (calorific value, fixed carbon, volatile matter, carbon, hydrogen). Samples were then subjected to thermogravimetric analysis to delineate the influence of organic composition on thermal decomposition. Septic tanks showed lower median fractions of lignin (9.4%dwb) but higher oil and grease (10.7%dwb), compared with ventilated improved pit latrines (17.4%dwb and 4.6%dwb respectively) and urine diverting dry toilets (17.9%dwb and 4.7%dwb respectively). High fixed carbon fractions in lignin (45.1%dwb) and protein (18.8%dwb) suggested their importance for char formation, while oil and grease fully volatilised. For the first time, this study provided mechanistic insights into faecal sludge pyrolysis as a function of temperature and feedstock composition. Classification into the following three phases was proposed: decomposition of hemicellulose, cellulose, other carbohydrates, proteins and, partially, lignin (200–380 °C), continued decomposition of lignin and thermal cracking of oil and grease (380–500 °C) and continued carbonisation (>500 °C). The findings will facilitate the development and optimisation of faecal sludge pyrolysis, emphasising the importance of considering the organic composition of the feedstock.

Fabrication and Characterization of Functional Ceramic Films by Solution Spray Pyrolysis: Correlations with the Thermal Decomposition Characteristics of the Constituent Salts

Thin films of ceramic or ceramic-metal (cermet) electrodes with appropriate structure and morphology are always sought in ceramic fuel cells and electrolyzers. These films can serve as either electrodes or electrolytes in solid oxide fuel cells (SOFCs) or electrolyzers (SOECs) requiring different morphological and structural characteristics for optimal function. Thus, electrode parameters such as thickness, porosity and tortuosity essentially determine the values of gaseous effective diffusivities and subsequently the extent of concentration polarization losses [1]. In addition, nanostructured thin film electrodes have shown enhanced conversion efficiencies compared to their bulk materials counterparts, essentially leading to low polarization losses [2].On the other hand, the electrolyte has to possess minimal porosity not allowing mixing between the anode and cathode compartments and adequately blocking electronic transport. Low thicknesses are desirable for minimization of the cell’s total ohmic resistance. However, at low electrolyte thicknesses, total ohmic cell polarization is affected by electrode microstructure to a greater extent than by electrolyte ohmic resistance due to contiguity factors between metal particles in the fabricated cermets and metal depletion in the anode functional layer [3].Generally, for a given set of chosen materials, all of the above microstructural requirements for electrodes and electrolytes have to be met by the adopted fabrication methods which have to be subsequently optimized with respect to their operational parameters. It is advantageous to resort to the so called innovative fabrication methods for the above, in particular for their functional components. The term refers to methods with the potential of producing nanostructural components and controlling in situ the film’s characteristics such as porosity, pore size, thickness and uniformity.The solution spray pyrolysis technique (SSP) belongs to this family of methods as it is based on molecular deposition and it involves spraying of a solution of suitable constituent metal salts onto a heated substrate [4].The technique is robust, environmentally friendly if water is used as solvent, easily upscalable and with easily controllable processing parameters. It also possesses the potential of producing very thin layers of components (i.e. < 1 μm) and therefore, reducing the subsequent sintering temperatures due to the more active precursor components of the constituent particles forming the final film.In a recent publication [4], we have shown that the technique can be optimized in terms of deposition temperature, time and concentration of the precursor salts in order to fabricate crack-free films of La0.75Sr0.25MnO3 (LSM) and CuO-CeO2 on dense YSZ substrates with thicknesses of the order of 0.65–3.5 μm. Cu-CeO2 constitutes a potential anode that combines the functionalities of copper ( an electronic conductor) and a good oxidation catalyst (i.e. CeO2) for potential hydrocarbon fuels fed into a SOFC while LSM is the typical state of the art cathode used with a YSZ electrolyte [5]. It was shown that lower deposition temperatures (but above the solvent boiling point) generally lead to more porous films and the precursor salt concentration is coupled with the optimal deposition temperature range and deposition time. In the present communication, we extend these findings in order to include films of Gadolinia (10mole%) stabilized Ceria (CGO10) on dense Zr0.92Y0.08O2 - x (YSZ) and La0.3Sr0.7FeO3 (LSF70) substrates. CGO10 is a typical solid electrolyte more suitable for intermediate temperature applications (i.e. 500-750°C) and it is amenable to being fabricated with lower porosities by SSP than YSZ [6]. Focus is on the thermal characteristics of the constituent salts with respect to correlations with the appropriate deposition temperatures as well as the effect of deposition time. The produced films are characterized by X-ray diffraction and scanning electron microscopy (SEM). CGO10 films were also characterized in terms of their electronic blocking capability in contact with the LSF70 substrates.

Thermal decomposition characteristics of low-grade rhodochrosite ore in N2, CO2 and air atmosphere

Thermal decomposition characteristics of low-grade rhodochrosite ore in N2, CO2 and air atmosphere

Fabrication and Characterization of Functional Ceramic Films by Solution Spray Pyrolysis: Correlations with the Thermal Decomposition Characteristics of the Constituent Salts

Thin films of ceramic or ceramic-metal (cermet) electrodes with appropriate structure and morphology are always sought as either electrodes or electrolytes in solid oxide fuel cells (SOFCs) or electrolyzers (SOECs) requiring different morphological and structural characteristics for optimal function. Requirements for the electrodes and electrolytes differ in each case and these dictate operational conditions of the adopted fabrication methods. The solution spray pyrolysis fabrication technique (SSP) is based on molecular deposition and it involves spraying of a solution of suitable constituent metal salts onto a heated substrate. In the present communication, we use this technique to fabricate thin films of Gadolinia (10mole%) stabilized Ceria (CGO10) on dense Zr0.92Y0.08O2-x (YSZ) and La0.3Sr0.7FeO3 (LSF70) substrates and La0.75Sr0.25MnO3 (LSM) and CuO-CeO2 on dense YSZ substrates. Focus is on the thermal characteristics of the constituent salts with respect to correlations with the appropriate deposition temperatures as well as the effect of deposition time.

Facile Template Free Shape Controlled Synthesis of α-Fe2O3 Truncated Octahedral Microstructures for the Thermal Decomposition of Ammonium Perchlorate

Background: The combustion behavior of the solid rocket propellants is highly dependent on the thermal decomposition characteristics of Ammonium Perchlorate (AP) and thus low-cost, facile and scalable preparation of the additive metal oxide-based catalysts is highly desired for the decomposition of AP. Objective: A template free one-step low-cost preparation of α-Fe2O3 for its use as a catalyst in the decomposition of AP. Methods: The catalyst is prepared by the simple heating of ferric chloride at 380 °C without any chemical treatment. The material is characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and high-resolution TEM (HRTEM). The catalytic thermal decomposition of AP over α-Fe2O3 was measured by Differential Scanning Calorimetry (DSC). Results: The material exhibited a pure α-Fe2O3 crystalline phase. Morphological investigations revealed the uniform formation of truncated octahedral microstructures of α-Fe2O3. DSC analysis confirmed the two-step exothermic thermal decomposition of AP with decreased decomposition temperatures with the catalytic assistance of α-Fe2O3. Conclusions: With the catalytic assistance of low-cost and easily prepared α-Fe2O3, the decomposition temperature was decreased by 30 ºC when compared to the pure ammonium perchlorate and a high decomposition heat release of 807 Jg-1 was observed.

Matured Theobroma Cocoa Pod Extracts as Green Inhibitor for Acid Corrosion of Aluminium

Matured Cocoa Pod Extract (MCPE) is prepared using Soxhlet extraction and is then characterized using Fourier Transform-Infra Red Spectroscopy (FT-IR), Gas Chromatography-Mass Spectroscopy (GC-MS). The thermal decomposition characteristics are studied using Thermo Gravimetric Analysis- Differential Thermal Analysis (TGA-DTA) method. FT-IR study confirmed the presence of hetero atoms like O, N, and GC-MS showed the presence of 15 chemical constituents of which 1,2-bis (trimethylsilyl) benzene is the major constituent present. TGA-DTA studies showed the thermal decomposition of chemical constituents which was supported by GC-MS data. The inhibition efficiency of MCPE is tested in 0.5M HCl medium taking aluminum as the target metal by Weight loss method (303K-308K). The anticorrosive property of MCPE was also tested using Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization methods (303K). In all the methods, the inhibition efficiency of MCPE was found to increase with an increase in % volume of the MCPE exhibiting good agreement with each other. Also, inhibition efficiency decreased with an increase in temperature, showing adsorption of inhibitor is by physisorption and thermodynamic parameters are measured. Tafel plots showed MCPE could retard both anodic and cathodic reactions, predominantly acting as an anodic type of inhibitor. Surface morphological changes of the metal were studied using Scanning Electron Microscopy which confirmed that MCPE acted as an inhibitor by adsorption mechanism.

Inverse Modeling of Thermal Decomposition of Flame-Retardant PET Fiber with Model-Free Coupled with Particle Swarm Optimization Algorithm.

The thermal decomposition model of flame-retardant polyethylene terephthalate (FRPET) fiber is essential for predicting its fire behavior and do relevant fire simulation. In this work, the thermal decomposition character of FRPET is investigated via thermogravimetric analysis at four heating rates. Two kinetic schemes are proposed based on the analysis of experimental data and model-free methods. The model-free methods (Friedman and advanced Vyazovkin methods) are employed to determine possible search range for particle swarm optimization algorithm with constriction factor (CFPSO). Thus, this coupled method could evaluate the kinetic parameters for two proposed schemes without initial guess. Both models could reasonably predict the experimental data with obtained parameters, and the second two-step consecutive model shows better performance. The performance of CFPSO on the second model is further compared with improved generalized simulated annealing algorithm, and CFPSO was found to be more effective. Furthermore, global sensitivity analysis was conducted via the Sobol method to investigate the influence of kinetic parameters for the second model on predicted results. The most influential parameters are ln A and Eα of the second reaction and reaction order n of the third reaction.

Experimental investigation on the effect of electron injection into air for thermal decomposition of solid waste

In this research, the thermal decomposition characteristics of cellulose, polyethylene, and their mixture with electron injected air were investigated using a laboratory-scale reactor. An electron generator with a voltage of 12 V was adopted as the key part to inject the electrons into the air in order to accelerate the thermal decomposition of the carbonaceous materials in the reactor. In addition, a modified fixed bed reactor was adopted to investigate the effects of the different parameters including the ON/OFF of the electrons injection into air, the thermal decomposition temperatures (400 °C and 500 °C) and the feedstock (cellulose, polyethylene and their mixture) on the syngas generation as well as the weight reduction rate. The results showed that the combustion reaction of char was more accelerated in the electron-ON case than that in the electron-OFF case. For example, in the case of cellulose, the amount of CO2 generation differs about 2 times between the electron ON and OFF cases. Also under the same conditions, the amount of CO generated can be suppressed to about 2/3 by the electron injection. In the case of polyethylene, the electron injection effect was confirmed only for enhancing the CH4 generation. However, there was a significant synergy effect in the electron-ON case for the cellulose and polyethylene mixture. These results showed that the electron injected air can accelerate the combustion reaction of char. The results suggest a potential advantage of electron injection to improve conventional waste incinerators.

Thermal Decomposition Characteristics of Poly((4-Vinylbenzyl) Trimethylammonium Bis (Trifluoromethanesulfonimide)) Studied by Pyrolysis-GS / MS

Over the past decades, significant advances have been made in the development and research of gas separation membranes based on ionic liquids (IL) and their polymer analogs (PIL) for membrane separation of "acid gases" such as CO2 and H2S from gas mixtures. Polymers containing various amino groups are of great interest for the selective separation of acid gases from gas mixtures, since ammonia and its derivatives are used in conventional purification. In this work, we have synthesized a monomeric ionic liquid based on 4 vinylbenzyl chloride with included triethylamine by the Menshutkin reaction. Further, on its basis, polymer ionic liquids were obtained by the method of free radical polymerization, then an anion exchange reaction was carried out to replace the Cl anion with Tf2N. To analyze the process of thermal pyrolysis of poly [VBTEA-Tf2N] a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) was employed in this research. The obtained materials, which are high molecular weight compounds, can be used to obtain polymer membranes of various architectures by traditional methods: both non-porous symmetric membranes and microporous asymmetric membranes.

Investigation on the self-decomposition and explosion hazard of azo compounds

Azo compounds are self-reactive chemicals that violently produce flammable gases with heat release (i.e., an exothermic reaction). However, the explosion mechanism and ignition probability of azo compounds have not been clearly defined for storage or transportation. In this study, explosion scene analyses and various pyrolysis tests were performed to evaluate the thermal decomposition characteristics and explosion phenomena of azo compounds in a storage facility. The chemical debris collected from a fire scene was determined to be similar to the pyrolyzate of one of the tested azo compounds used by Py-GCMS. The minimum amounts of azo compounds, which could be ignited by self-decomposition heat, were calculated from the results of differential scanning calorimetrys and the heat transfer equation. The results were used to discuss a safety and response strategy for preventing the propagation of an explosion accident, namely a chemical backdraft.

The effects of TiH2 on the thermal decomposition performances of ammonium perchlorate-based molecular perovskite (DAP-4)

ABSTRACT In order to promote the development of molecular perovskite energetic materials, studying thermal decomposition performances of AP-based molecular perovskite energetic materials ((H2dabco)[NH4(ClO4)3], DAP-4) catalyzed by metal hydrogen storage fuel is significant. In this study, the morphology, structure and thermal decomposition characteristics of TiH2, DAP-4 and DAP-4/TiH2 composite materials were characterized and investigated. The experimental results showed that the DAP-4 peak exothermic temperature at different heating rates both showed a decreasing trend with TiH2 content increased. With 20 wt% TiH2 added, the DAP-4 peak exothermic temperature decreased from 394.3 ℃ to 352.8 ℃ (10 ℃/min heating rate), and the apparent activation energy (Ea ) also decreased from 201.5 KJ/mol to 182.3 KJ/mol. A possible catalytic thermal decomposition mechanism of perovskite catalyzed by TiH2 was proposed. This work is helpful to further understand the thermal decomposition characteristics of molecular perovskite energetic materials in the presence of metal hydrides.

Thermal decomposition characteristics of retained austenite and its influence on impact toughness of B-containing 9Cr1Mo1Co(FB2) steel during the two-step tempering

The decomposition kinetics of retained austensite (RA) and the effect of its decomposition on the impact toughness of FB2 steel during the two-step tempering were studied by employing differential scanning calorimetry (DSC), magnetic saturation measurement (MSM) and transmission electron microscopy (TEM). Furnace-cooling from 1100 °C produces 9.7vol.% filmy RA due to the contributions to Ms from the C enrichment (MS(Che) = 102 °C) and the high internal stress (ΔMS(stress) = -93.3 °C). With the increase of the first step tempering temperature from 570 °C to 630 °C for 1–10 h, RA involves into the different decomposition characteristics, forming θ phase, M3C particles, filmy M3C and M7C3, and also leading to the volume fraction of the carbon-depleted RA transformed into martensite fγRA→M decrease from 87.6% to 0.0% during the subsequent cooling process. During the second step tempering at 670 °C, these θ and M3C particles evolve into spherical M23C6, while film-like M3C and M7C3 evolve into filmy M23(C,B)6. Deteriorated by the filmy M23(C,B)6, the impact toughness increase from 72 J/cm2 to 118 J/cm2 with the increase of fγRA→M from 0% to 87.6%. While for the samples with fγRA→M=0, enhancing the second step tempering temperature to 690 °C for 10 h can further promote the spheroidization of filmy M23(C,B)6 and reduce hardness, resulting in the enhancement of impact toughness from 72 J/cm2 to 112 J/cm2. In summary, a two-step tempering process (570 °C for 1–5 h plus 670–690 °C for 10 h) for RA-containing FB2 steel is suggested to obtain excellent impact toughness and high hardness.

Effects of phase change material (PCM)-based nanocomposite additives on thermal decomposition and burning characteristic of high energy propellants containing RDX

A kind of phase change material (PCM)-based nanocomposite was prepared and added into high energy propellants containing RDX as additives to investigate its effect on thermal decomposition and burning characteristic of high energy propellants. The effect of PCM-based nanocomposites on thermal decomposition of high energy propellants is investigated by TG/DSC-FTIR-MS technology. Due to the delayed protection effect (PCM-based nanocomposites can absorb lots of heat at the range of certain temperature when it undergoes structure change or phase transitions) of PCM-based nanocomposites under the thermal decomposition condition, the thermal stability of high energy propellants modified with PCM-based nanocomposites is improved. At the same time, the concentration of N2, NO2, H2O and CO2 is increased during thermal decomposition of high energy propellants whereas NO and CO is decreased. The burning gaseous products and burning characteristic of high energy propellants are studied by the combination of closed bomb test and Fourier transform infrared spectrum. The main burning gaseous products are N2, CO2, CO, H2O, CH4, etc. After the high energy propellant modified with PCM-based nanocomposites, the concentration of CH4 is increased while CO, CO2 and H2O is decreased under the high-pressure burning condition. The progressivity factor of high energy propellants is increased by 22.2% compared with the control sample while the maximum pressure is merely decreased 1.25% after the addition of the PCM-based nanocomposite, thus PCM-based nanocomposites can be used to adjust the burning process and improve the burning progressivity of high energy propellants. This study is expected to boost the practical application of PCM-based nanocomposite to the propellant formulation and effectively control the burning characteristic of high energy propellants.

Slow pyrolysis of an LDPE/PP mixture: Kinetics and process performance

High- and low-density polyethylene (HDPE and LDPE) and polypropylene (PP) are the most common polymers among plastic waste as they have multiple commercial applications. This study focused on thermal degradation characteristics and kinetic of a plastic mixture with a composition of 92.5 wt% LDPE and 7.5% PP. Thermal decomposition characteristics of the plastic mixture was analysed through thermo-gravimetric analysis (TGA). The overall kinetic of the process was studied using the modified Coats−Redfern method and the Ozawa-Flynn-Wall (OFW) method. The apparent activation energy (E) and pre-exponential factor (A) obtained were 316.0 kJ/mol; 8.09E+21 min−1 and 311.5 kJ/mol; 4.35E+21 min−1, respectively. Slow pyrolysis of the analysed mixture was carried out in a semi-batch reactor under atmospheric pressure and nitrogen atmosphere and three different pyrolysis temperatures were investigated: 420 °C, 450 °C and 500 °C. H2, CH4, C2H4, C2H6 and C3H8 were the main components of the gas phase. Liquid (oil/wax phase) yields increased with increasing operative temperature from 42% at 420 °C to 62% at 500 °C. On the other hand, solid phase showed a specular behaviour compared to the oil/wax phase, decreasing from 21% to 5% in the considered temperature range. On the contrary, gas phase did not change much with pyrolysis temperature, with a decrease from 37% at 420 °C to 34% at 500 °C. Products’ energy yields were also estimated at 420 °C. They ranged from 7.4% to 37.8% and 43.0% for solid, gas and oil fraction, respectively. Oil fraction collected from pyrolysis at 420 °C was also characterized.

Co-hydrothermal carbonization of different feedstocks to hydrochar as potential energy for the future world: A review

Co-hydrothermal carbonization (co-HTC) has emerged recently as a promising thermochemical technique that can transfer organic solid residue (e.g., biomass, sewage sludge, plastic, livestock manure) into value-added products (i.e., hydrochar). This advanced mechanism conceals the weakness of hydrochars derived from the hydrothermal carbonization (HTC) of a single feedstock. The co-HTC of various feedstock blends used for hydrochar is reviewed in this article. Biomass/sludge, biomass/plastic, biomass/coal, biomass/manure were the most common feedstock blends. Many studies have found that co-HTC, compared to single feedstock, enhances the yield, ultimate and proximate properties, higher heating value (HHV), thermal behaviors, and overall quality of hydrochars. The synergistic effects of feedstock types, blending ratio, temperature, and residence time are also discussed. The feedstock mixing ratio emerges as the most important variable, followed by feedstock types, temperature, and reaction time. Thermogravimetric (TG) and derivative thermogravimetric (DTG) analyses have made it possible to better understand the thermal decomposition characteristics of hydrochars. In most papers on this subject, the range of combustion temperature and comprehensive combustion index (CCI) has increased. Overall, the physicochemical and thermal behaviors of hydrochar derived from co-HTC make it energy-efficient and environmentally sound by reducing the waste load and avoiding pollution issues. Additionally, several important suggestions have been recommended for future advances being made in co-HTC of feedstocks and its comprehensive application.