Pyrolysis Of Blends Research Articles

Thermogravimetric study on thermal degradation kinetics and polymer interactions in mixed thermoplastics

AbstractPotential interactions during thermal degradation of polymer blends significantly influence product yields and their composition. Therefore, chemical recycling of plastic waste requires fundamental understanding of feedstock dependency for effective process design. This study investigates the pyrolysis of polymer blends (HDPE, LDPE, PP, PS, ABS, PET, PA6, PVC) through thermogravimetric experiments at different heating rates. Sample homogeneity’s impact on interactions is analyzed using particles, powder, coextruded blends, and samples in crucibles with separated compartments. A kinetic model is presented to support the experimental findings, assuming linear superposition of individual polymer kinetics. A proposed grouping of thermoplastics, reflecting their degradation behavior and potential interactions, correlates with the polymer structure. Observed interactions, particularly in blends of heteroatom-containing polymers (N, O, Cl), are accelerated reactions and coke formation. Hence, the model accurately predicts the degradation of heteroatom-free polymer mixtures but encounters challenges with more complex blends. This comprehensive study emphasizes the importance of feedstock composition for future pyrolytic polymer recycling. Graphical abstract

Generation and emission mechanism of polycyclic aromatic hydrocarbon (PAHs) during the coking process in Shanxi, China

Although coking process is the important source of polycyclic aromatic hydrocarbons (PAHs) in the environment, the generation and emission of PAHs during this process is unclear. It is crucial to clarify the formation mechanism of PAHs in coal pyrolysis during the coking process for effectively identifying and controlling the emission of these organic pollutants. In this study, the combination of laboratory simulation and field sampling was used to analyze the mechanism of PAHs formation and emission in coking process. The release of PAHs from the pyrolysis process of coal blends used in coking plants was 1778.20 ± 111.95 μg · g−1, which was much higher than the content of free PAHs in raw coal (76.50 ± 12.46 μg · g−1). 3-ring PAHs were the most abundant components of free PAHs and pyrolysis-generated PAHs. PAH formation during pyrolysis of coal blends was primarily attributed to the cracking of the macromolecular structure of coal, with minimal influence of free PAHs in blended coal. The emission of PAHs from coal-charging was higher (62.93 ± 17.75 μg · m−3) than that from pushing of coke (11.79 ± 1.91 μg · m−3·, PC) and combustion of coke oven gas (5.53 ± 1.20 μg · m−3, CG), and was mainly related to free PAHs in coal. In contrast, the characteristics of PAHs in the flue gas of PC and CG were similar to those from blended coal pyrolysis. PAHs in fugitive emission from coke oven were primarily affected by flue gas leakage and were mainly related to coal pyrolysis and free PAHs in blended coal.

Effect of the catalyst type on pyrolysis products distribution of polymer blends simulating plastics contained in waste electric and electronic equipment

The valorization of the plastic part from waste electric and electronic equipment (WEEE) is of significant importance for the upcycling of this waste stream with pyrolysis proposed as an appropriate, environmentally friendly, thermo-chemical recycling technique. The subject of this study is to investigate the distribution of the products obtained after the addition of certain catalysts in the pyrolysis of polymer blends with a composition similar to that of plastics in WEEE. Specifically, blends of acrylonitrile-butadiene-styrene (ABS), high impact polystyrene (HIPS), polycarbonate (PC), polypropylene (PP) and poly(vinyl chloride) (PVC) were examined in experiments taking place in a lab scale pyrolyser coupled with gas chromatography/mass spectrometry (Py-GC/MS) for the on-line recording of the products obtained. Six different catalysts (CaO, γ-Al2O3, Fe2O3, ZSM-5, Silicalite, Al-MCM41) were used and the optimum pyrolysis temperatures were selected for each system based on evolved gas analysis. The results from catalytic cracking were compared and evaluated in terms of the number of compounds produced, the ratio between aromatic and aliphatic products, and the intensity of the peaks. It was found that the best choice for the decomposition of ABS is Fe2O3 and for HIPS the Al-MCM41. γ-Al2O3 affects PC degradation and CaO exhibits specific selectivity to this polymer. Pyrolysis of blends results in the production of a mixture of hydrocarbons together with other aliphatic and aromatic compounds. Polymer blends including chlorinated compounds such as PVC start degrading at relatively low temperatures, slightly over 200 °C. Degradation occurs in two steps with peaks around 300 and 465 °C, respectively. The first is attributed to the removal of halogenated compounds and the second to the scission of the main carbon chain. PVC degradation produces chlorine radicals that affect the degradation mechanism. The presence of the catalysts did not significantly change the temperatures of degradation. However, they do change the type of the products obtained. Pyrolysis of the styrenic polymers, i.e. ABS or HIPS resulted in mainly aromatic compounds with one, two or even three aromatic rings, whereas PC results in several phenols. CaO is proposed as the best choice for catalytic cracking of Blend A, whereas Silicalite should be considered for Blend B since it leads in the production of more aromatic compounds compared to conventional pyrolysis.

Investigation of zeolite H-β effect on pyrolysis of polystyrene by multiple kinetic analysis methods.

For studying the effects of H-β zeolite on the pyrolysis of polystyrene (PS), non-isothermal thermogravimetric measurements were conducted in N2 under 5, 10, 15, and 20K/min. The results show that the addition of 10 ~ 30 wt.% H-β zeolite can significantly decrease the initial pyrolysis temperature of PS, indicative of the catalytic effect of zeolite used. Through kinetic analysis of the pyrolysis of PS blends, the isoconversional activation energies are calculated to be 121.8 ~ 191.9, 92.1 ~ 173.8, and 116.7 ~ 192.4kJ/mol for the PS blends with zeolite loading of 10, 20, and 30 wt.%, respectively. Meanwhile, the pyrolysis degradation functions are determined through the Master-plots method integrated with a recently developed compensation-effect method to follow chemical reaction mechanism with the reaction order of 0.9, 1.0, and 0.6 for PS/zeolite blends of 10, 20, and 30 wt.% loading, and their pre-exponential factors are respectively calculated to be 6.18 × 108 ~ 5.71 × 1011, 2.36 × 106 ~ 9.23 × 1011, and 8.38 × 107 ~ 1.11 × 1012min-1. Our work may provide some insights for how to better describe experimental results with theoretical predications and necessary information for performing any potential pyrolysis designs.

Preparation of carbon-based microwave absorbing materials by hybrid activation pyrolysis of lignin and coal

• Preparation of carbon materials by potassium hydroxide activation. • Lignin and coal synergistically improved the microwave absorption performance. • The best reflection loss of the prepared carbon-based material was -61.02 dB. In this work, the cheap and eco-friendly microwave absorber materials were prepared by the activation pyrolysis of lignin and coal blends. The microwave absorption performance of the carbon materials prepared by mixing and activation of lignin and coal is more than twice as high as that of pure coal and lignin carbon-based materials. The optimum reflection loss of -61.02 dB at 6.16 GHz and less than -10 dB in the frequency range of 4.72 GHz to 7.6 GHz, with an effective absorption bandwidth of 2.88 GHz. The results indicate that the lignin and coal mixture have a synergistic effect during pyrolysis, which can effectively improve the pore structure and graphitization degree of the carbon material, thus improving the microwave absorption performance of the material. This study provides a low-cost and effective way to produce lightweight and efficient microwave absorbing materials.

Hydrogen-Rich and Clean Fuel Gas Production from Co-pyrolysis of Biomass and Plastic Blends with CaO Additive.

The treatment and disposal of waste biomass and plastics are of great importance to achieve both waste management and resource recycling. In this work, pyrolysis of biomass and plastic blends were investigated to identify the influence of temperature and in situ CaO addition on the production of hydrogen-rich, HCl-free, and low tar content fuel gases. The results show that the increase in temperature and the use of CaO significantly improved both the quantity and quality of the fuel gas and mitigated the formation of tar compounds and HCl. Moreover, H2 yield was significantly improved from 0.30 to 3.68 mmol/g with the increase in temperature from 550 to 850 °C. Also, the use of in situ CaO significantly increased the H2 yield by 28–88%. The H2/CO ratio was also enhanced from 0.35 to 1.50 with the temperature increase and CaO addition. Tar removal efficiency reached approximately 70.09% with the use of CaO at 850 °C. The produced HCl gas could be effectively absorbed by CaO through dechlorination reactions to form CaClOH at a highest mitigation efficiency of 92.37%. The results could be used to develop clean and efficient treatment technologies of waste biomass and plastics.

Study of co-pyrolysis kinetics, synergetic effects, and thermodynamics of coal and biomass blends

ABSTRACT The present work investigates the thermochemical conversion characteristics, reaction kinetics, and thermodynamic behavior of coal and biomass (Rice husk (RH)) blend pyrolysis in a TG reactor. Three different proportions of biomass (75, 50, and 25%) are blended with sub-bituminous Indian coal for the co-pyrolysis study. Pure coal and pure RH pyrolysis is characterized by three reaction stages, whereas the blended sample shows a four-stage thermal degradation reaction. A significant synergy is not found in the present study. Model-free techniques (FWO, KAS, and Starnik) are used to estimate the activation energy for various blending mixtures of the feed samples. The activation energy obtained for the equal mass ratio of coal and RH using the KAS, FWO, and Starnik methods is 61.45, 76.58, and 75.54 kJ/mol, respectively. The reaction order for coal: RH blend 25:75, 50:50, and 75:25 is estimated to be 4, 2.4, and 1.3, respectively. The favorable activation energy (Eα ) is found for the blending mixture of 50% coal and 50% RH. The positive value of ΔH indicates the endothermic nature of pyrolysis. The positive and negative values of ΔS indicate the complexity and nonspontaneous nature of coal and biomass blend pyrolysis. The average Entropy (ΔS) for an increasing % of coal is decreasing and the value comes to negative for 75% coal, indicating that thermal equilibrium is favorable for a higher % of coal.

Co-pyrolysis of cashew nut, coconut shells, and rice husk waste: kinetic and thermodynamic investigations

ABSTRACT Co-pyrolysis of low ash content of coconut shell (CNS) and cashew nuts shells (CCS), and high ash content rice husk (RH) blends was performed using thermal gravimetric analysis (TGA). RH was blended with both CCS and CNS at 0, 30, 60, and 100% RH by mass. Results showed that CCS and CNS have low ash contents of 2.7 and 1.5%, respectively, while RH has high ash content of 26.7% on dry basis. TGA under nitrogen gas study was carried out at three heating rates of 10, 15, and 20 K/min. It was observed that the increase of CCS/CNS increased decomposition rates of blends. For example, RH increased from 6 to 7.7%/min when CNS was added. Furthermore, addition of low ash content leads to high decrease of maximum decomposition rates compared to high-high or low-low ash blends. Synergistic analysis has found out that a positive effect is observed when CNS/CCS is added to RH. The decrease of maximum decomposition temperature of 60–63°C compared to other studies of 10°C for all low and 40° for all high ashes is of great advantage. Flynn-Wall-Ozawa (FWO), Kissinger-Akahra-Sunose (KAS), and DAEM kinetic model analysis for 0.1 ≤ α ≤ 0.75 were used between 315 and 840°C. FWO model gave activation energy of 85, 70, and 75 kJ/mol, for RH, CNS, and CCS, respectively. Addition of low ash content biomass reduced activation energy of RH, activation energy of RH was reduced from 85 to 72 kJ/mol when CNS was added. RH requires high energy than the rest, example, RH needed 66.29 kJ/mol of energy compared to 51% of CNS and 56 kJ/mol for CCS. The entropy results were negative which implies a different orientation of molecules from origin samples properties. The Gibbs-free energies were positive and thus non-spontaneous process. Empirical models generated using SB model indicated that kinetics depends on reaction order and acceleration mechanism rather than diffusion and nuclei growth. Kinetically, the blending of high and low ash content biomass leads to high decrease of operating temperature and activation energy compared to low-low or high-high ash content blends. It has been recommended to further study on quality and quantity of product from such blends and the possibility of pre-treatment methods such as microwaves to improve pyrolysis of such blend.

Optimization of process parameters using response surface methodology for maximum liquid yield during thermal pyrolysis of blend of virgin and waste high-density polyethylene

Optimization of process parameters using response surface methodology for maximum liquid yield during thermal pyrolysis of blend of virgin and waste high-density polyethylene

Catalytic pyrolysis of polymers with brominated flame-retardants originating in waste electric and electronic equipment (WEEE) using various catalysts

The increasing volume of plastics in waste electric and electronic equipment (WEEE) together with the existence of potentially hazardous compounds make it of paramount importance to explore advanced recycling techniques for controlling the formation of undesirable products while enhancing the formation of the desirable ones. Harmful compounds could be formed during their recycling by pyrolysis because of the brominated flame-retardants usually incorporated into the plastics originating in WEEE. This paper examines catalytic pyrolysis of polymeric blends that consist of acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), polycarbonate (PC) and polypropylene (PP), in the absence and presence of a brominated additive: tetrabromobisphenol A (TBBPA), with a view to reducing the bromo-compounds formed during their pyrolysis, while favouring the production of valuable compounds, such as phenols. Five catalysts: Al2O3, Fe/Al2O3, MgO, Fe/MgO and ZSM-5 with different textural properties were evaluated for their performance during pyrolysis of the mentioned blends at 440 °C (peak degradation temperature). It was found that all catalysts promoted the production of phenolic compounds, which are valuable products that can be further used in chemical industries. Among all catalysts tested, the best one was considered to be Fe/Al2O3, since it led to larger amounts of phenols for all blends examined. As for their debromination efficiency, attention was given on the reduction of dibromophenol formed, due to the presence of TBBPA in the polymeric blends. Results showed that Fe/Al2O3 was the optimal catalyst since it led to bromine reduction greater than ∼75%. Fe/MgO was the second one leading to reduction greater than 60% and MgO led to an important reduction (greater than ∼55%).

Effects of Additives on Coke Reactivity and Sulfur Transformation during Co-pyrolysis of Long Flame Coal and High-Sulfur Coking Coal.

A silica-aluminum-based mineral (GL) was selected for inspecting the effects of interactions of minerals in coal blends on the coke reactivity index (CRI) and sulfur transformation during co-pyrolysis of long flame coal and high-sulfur coking coal. Results indicate a good compatibility for the supply of active hydrogen, decomposition of sulfur, and regulation of reactivity. The experimental values of sulfur content in different coal blend cokes are lower than the calculated values, which can be determined as a result of the directional regulation effect of long flame coal on sulfur transformation. The addition of GL in coal blends significantly reduces the CRI of the corresponding coke, and the effect of GL on coke reactivity is also verified by a 10 kg coke oven experiment. When increasing the ratio of long flame coal, the sulfur fixation in the solid phase has a tendency to be enhanced by alkaline minerals. Also, GL plays a role in reducing the capture of sulfur free radicals by alkaline minerals, which improves the sulfur removal during pyrolysis of coal blends and then reduces the sulfur content in coke. This work provides a reference for using silica-aluminum-based minerals to reduce the capture of sulfur and catalytic effect on coke reactivity.

Pyrolysis characteristics of RDF and HPDE blends with biomass

The main objective of this work was to study refuse-derived fuels (RDF) and high-density polyethylene (HDPE) upgrading by pyrolysis of blends of these materials with wood. The study considered three operational conditions: cracking temperature, heating rate, and different wt.% of RDF and HDPE. The results demonstrate that the cracking temperature of 500 °C and the faster heating rates increased the liquid yield for RDF blends. On the other hand, HDPE blends favor gas production at 550 °C and faster heating rates, which enhance the process operativity because polymeric materials generate waxes and are reduced beneath such conditions. Finally, produced gas LHV increases as RDF and HDPE were added. For example, the LHV of the produced gas only with wood at 550 °C and 20 °C/min was 10.34 MJ/m3 and with 25 wt% HDPE was 14.82 MJ/m3.

Effect of brominated flame retardant on the pyrolysis products of polymers originating in WEEE.

Chemical recycling is an environmentally friendly method, which is often used for the recycling of plastics included in waste electric and electronic equipment (WEEE), since fuels and secondary valuable materials can be produced. Brominated flame retardants (BFRs) are usually added into these plastics to reduce their flammability; but they are toxic substances. The aim of this work is to examine the thermal behaviour and the products obtained after pyrolysis of polymer blends that consist of acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), polycarbonate (PC) and polypropylene (PP) with composition that simulates real WEEE, in the absence and presence of a common BFR, tetrabromobisphenol A (TBBPA), in order to investigate its effect on pyrolysis products. Blends were prepared via the solvent casting method and the melt-mixing in an extruder; it was revealed that the latter method may be a better choice for blends preparation, since it did not affect the products obtained. The chemical structure of each polymeric blend was identified by Fourier transform infrared spectroscopy (FTIR). Thermal degradation of the blends was evaluated by thermogravimetric (TG) experiments performed using a thermal analyser (TGA) and a pyrolyser for evolved gas analysis (EGA). It was observed that blends had a similar behaviour during their thermal degradation; and in most cases, they followed a one-step mechanism. Pyrolysis products were identified by the pyrolyser combined with a gas chromatographer/mass spectrometer (GC/MS), and comprised various useful compounds, such as monomers, aromatic hydrocarbons and phenolic compounds that could be used as chemical feedstock. Furthermore, it was found that TBBPA affected products distribution by enhancing the formation of phenolic compounds and on the other hand by resulting in brominated compounds, such as dibromophenol.

Thermal conversion behavior and nitrogen‐containing gas products evolution during co‐pyrolysis of cow manure and coal: A thermal gravimetric analyzer/differential scanning calorimetry–mass spectrometer investigation

AbstractThe kinetics and thermal behaviors of cow manure (CM) and Meihuajing bituminous coal (MHJ) blending from room temperature to 950°C were investigated by thermal gravimetric analyzer (TGA) coupled with differential scanning calorimetry (DSC) and mass spectrometer (MS). TG curves show that the high heating rate accelerates thermal decomposition rate, and the position of differential thermal gravity (DTG) peaks shifts to a higher temperature. Owing to the heat transfer limitation phenomenon, the residual weight of CM is only 40.38% with the heating rate of 1°C/min in comparison with other heating rate. DSC takes more time to reach a steady state than TGA. Gaseous evolution curves of HCN and NH3 were obtained during the pyrolysis of blends based on TG–MS experiments. With the increased heating rate, the emissions increased a lot due to the secondary reaction of volatiles. The Eα of 1C1M obtained using Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), Friedman, and Kissinger methods is within 124.58–317.18, 121.97–321.11, 150.28–331.64, and 209.26 kJ/mol, respectively. The kinetic parameters calculated based on four model‐free kinetic modeling methods shows good agreement. And the thermodynamic parameters were obtained and discussed under different conversion rates. This work is greatly important to understand the co‐prolysis mechanism of CM and coal and to design the pyrolysis reactors.

Determination of Kinetic and Thermodynamic Parameters of Pyrolysis of Coal and Sugarcane Bagasse Blends Pretreated by Ionic Liquid: A Step towards Optimization of Energy Systems

Pyrolysis behavior of ionic liquid (IL) pretreated coal and sugarcane bagasse (SCB) blends through thermogravimetric analysis (TGA) was studied. Three blends of coal and SCB having 3:1, 1:1, and 1:3 ratios by weight were treated with 1-ethyl-3-methylimidazolium chloride ([Emim][Cl]) at 150 °C for 3 h. Untreated and IL treated blends were then analyzed under pyrolytic conditions in a TGA at a constant ramp rate of 20 °C/min. Kinetic and thermodynamic parameters were evaluated using ten Coats-Redfern (CR) models to assess reaction mechanism. Results showed that the untreated blends followed a definite pattern and were proportional to the concentration of SCB in the blends. IL treated blends exhibited a higher average rate of degradation and total weight loss, indicating that IL had disrupted the cross-linking structure of coal and lignocellulosic structure of SCB. This will enhance the energy generation potential of biomass through thermochemical conversion processes. The lower activation energy (Ea) was calculated for IL treated blends, revealing facile thermal decomposition after IL treatment. Thermodynamic parameters, enthalpy change (ΔH), Gibbs free energy change (ΔG), and entropy change (ΔS), revealed that the pyrolysis reactions were endothermic. This study would help in designing optimized thermochemical conversion systems for energy generation.

Inhibition effect of methanol addition on carbon deposition in propane pyrolysis

Methanol-mixed fuels consisting of methanol, propane, and a small amount of auxiliary solvent are widely used as inexpensive industrial fuels, but the carbon deposition in the pyrolysis of this fuel seriously restrains its popularization. This paper studied the characteristics of gaseous products and carbon deposition in the pure propane and methanol-propane mixture pyrolysis experimentally, analyzed the effect of methanol addition on the reaction path of propane pyrolysis and production rate of key species by using detailed reaction mechanism. Results show that methanol addition can restrain C2H4 converting to C2H2 in the later stage of pyrolysis. The carbon deposition rate and particle diameter increase exponentially with the increase of reaction temperature in both pure propane and methanol-propane blend pyrolysis. Methanol addition can significantly reduce the carbon deposition rate and particle diameter. The reaction path analysis indicates that the main reaction paths forming benzene are C3H3 → A1 and C4H4 → I-C6H6 → A1, and C3H3 is a key specie to form benzene. The pyrolysis of methanol-propane mixture generates more H2 and H than that of pure propane pyrolysis, which makes most C3H6 convert to C2H4, reduces the amount of C3H3 and suppresses the conversion of C2H4 to C2H2. And then the amount of benzene is reduced significantly and the generation of subsequent PAHs and carbon deposition is inhibited. Lots of H2 also restrains the hydrogen abstraction from benzene resulting in the delay of the formation of PAHs and carbon deposition. This study is of great significance to research the soot formation in hydrocarbon combustion with alcohol fuel.

A kinetic study of microalgae, municipal sludge and cedar wood co-pyrolysis

In the present study, pyrolysis kinetics of the pure and blends of cedar wood (CW), algal biomass (AB), and digested sludge (DS) with and without the catalyst ZSM–5 were examined. Both Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) model-free methods were used to calculate the total activation energy (Ea), change in enthalpy (ΔH), and change in Gibb’s free energy (ΔG) of 18 different biomass combinations. The highest Ea (548.52 kJ/mol) and ΔH (532.22 kJ/mol) were found for the CW. The biomass blend of AB: CW at weight ratios of 2:1 with catalyst (2:1 catalyst to biomass weight ratio) resulted in the lowest Ea (57.03 kJ/mol) and ΔH (50.11 kJ/mol) with a ΔG value of 243.25 kJ/mol. Statistically significant response surface models were developed to describe the effect of biomass blend composition on Ea and ΔH. This study demonstrated that catalytic pyrolysis of biomass blends from different sources can be used to significantly reduce the energy requirement for the process.

Co–pyrolysis of biomass blends: Characterization, kinetic and thermodynamic analysis

The present study has dealt with characterization and co–pyrolysis of binary and ternary blends of three biomass, viz. water hyacinth (WH), Thevetia peruviana (TP) and sugarcane bagasse (SCB). The biomass blends were characterized for proximate and ultimate analysis, surface morphology and functional groups. Co–pyrolysis of blends was carried out using a thermogravimetric analyzer (TGA) at heating rates of 8, 10, 15 and 30 °C min−1. TGA data was analysed using Ozawa–Flynn–Wall (OFW), advanced isoconversional model of Vyazovkin (Vyazovkin _AIC) and distributed activation energy model (DAEM). The dominant reaction mechanism of co–pyrolysis at different stages of conversions was deduced using Criado plots. The kinetic parameters of activation energy and pre–exponential factor, and thermodynamic parameters of ΔH and ΔS showed large variation with conversion, which is indicative of complex chemistry of thermal conversion of various structural components of biomass with synergistic interactions. The activation energies for binary blends WH SCB, WH TP, TP SCB were in the range 122.90–237.53, 127.93–272.92, and 124.80–235.94 kJ mol−1, respectively. For ternary blends WH 111, WH 211 and WH 311, activation energy varied in the range 119.64–194.31, 123.40–246.80, and 121.65–194.75 kJ mol−1, respectively. The predominant reaction mechanism for all blends was ordered reaction (F1) in lower conversion range (α ≤ 0.25), and diffusion limited process (D1 or D2 or D3) in higher conversion range (α = 0.35–0.55). Positive ΔH for all blends indicated endothermic nature, while positive ΔS indicated more disordered system after reaction – typical of pyrolysis.

CO-pyrolysis of bituminous coal and coconut shell blends via thermogravimetric analysis

ABSTRACT The thermal behavior of bituminous coal, coconut shell, and their blends during pyrolysis process was investigated in this study. The experiments were conducted at different weight percent of coconut shell (10, 20, 30, 40, and 50 wt%) and temperatures ranging from 30°C to 900°C. The DTG data for fuel blends showed additive profiles that reflected behavior of the individual fuel. When coconut shell was mixed with coal under weight percent of 20–50%, the nature of peaks in DTG profiles changed from higher to lower in the third stage reaction, shifting devolatilization temperature from 400°C to 450°C. This led to a decrease in the maximum rate of mass loss from 10.6% to 7.4%/min. However, the 10 wt% blend caused a slight increase in the maximum rate of mass loss from 10.6% to 11%/min. In addition, co-pyrolysis kinetics of fuel blends indicated that the blending of coconut shell with coal at BBR higher than 30% can increase the value of activation energy and induce slow pyrolysis of blends.

Investigation into the co-pyrolysis behaviors of cow manure and coal blending by TG–MS

In this study, the co-pyrolysis characteristics of cow manure (CM) and Meihuajing bituminous coal (MHJ) blends were investigated in detail. The mass loss behavior and gas evolution characteristics of the blends were analyzed online by thermogravimetry–mass spectrometry (TG–MS), and kinetic analysis was performed. The results demonstrate that the addition of CM to the MHJ increases the reactivity of blends, indicating that interaction between the CM and MHJ occurred during co-pyrolysis. For conventional gases, the release order of gases during CM and MHJ blend pyrolysis is H2O, CO2, CO, CH4, H2. For sulfur-containing gases, with increasing proportion of CM, the emissions of H2S, COS, and C4H4S increase and that of SO2 decrease, and the release temperature interval shifts to lower directions. The Coats & Redfern model was used, an increase of activation energy with CM addition was observed. The optimum blending ratio based on the lowest activation energy is CM:MHJ = 1:3 and the activation energy is 41.9 kJ/mol.