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Tetra Pak® paper and PE (polyethylene) wastes were evaluated to obtain a new composite material with awareness of environmental responsibility. Fillers and coupling agents were used for this joining process. Calcite (CaCO3), boric acid (H3BO3), SPT (Sodium Perborate Tetrahydrate / NaBO3.4H2O), titanate, MAPE (maleic anhydride grafted polyethylene, and vinyltriethoxysilane (C8H18O) composites were produced in 30 × 30 cm plates. A total of 30 samples were prepared as 5 mg flour for thermogravimetric analysis (TGA). Samples were observed in a thermal analyzer at 10, 15, or 20 °C/min heating rate in nitrogen atmosphere. Graphs were obtained as a result of TGA, and the activation energies were calculated using these graphs. The activation energy was calculated using the Flynn-Wall-Ozawa method. The determined activation energies of the composites were close to each other for each temperature group. In the samples using calcite and vinyltriethoxysilane, relatively higher activation energies were observed in comparison to the samples with boric acid and MAPE.

Tetra Pak® paper and PE (polyethylene) wastes were evaluated to obtain a new composite material with awareness of environmental responsibility. Fillers and coupling agents were used for this joining process. Calcite (CaCO3), boric acid (H3BO3), SPT (Sodium Perborate Tetrahydrate / NaBO3.4H2O), titanate, MAPE (maleic anhydride grafted polyethylene, and vinyltriethoxysilane (C8H18O) composites were produced in 30 x 30 cm plates. A total of 30 samples were prepared as 5 mg flour for thermogravimetric analysis (TGA). Samples were observed in a thermal analyzer at 10, 15, or 20 °C/min heating rate in nitrogen atmosphere. Graphs were obtained as a result of TGA, and the activation energies were calculated using these graphs. The activation energy was calculated using the Flynn-Wall-Ozawa method. The determined activation energies of the composites were close to each other for each temperature group. In the samples using calcite and vinyltriethoxysilane, relatively higher activation energies were observed in comparison to the samples with boric acid and MAPE. [ABSTRACT FROM AUTHOR]

The effects of different hot air speeds and temperatures on the drying characteristics of half-ripe rice paper were investigated by hot air convection drying experiments. The thin-layer drying experiments were carried out at three different combinations of air speeds of 1.97 m/s, 3.00 m/s, and 3.90 m/s and temperatures of 85 °C, 100 °C and 115 °C. The results show that among the 10 drying kinetic models selected, the Modified Page model is the most suitable model to describe the drying characteristics of the thin layer of half-ripe rice paper; the whole drying process exists obvious ascending, constant and descending processes; the effective moisture diffusion coefficient of half-ripe rice paper is in the range of 1.52656 × 10−9 m2/s–3.15816 × 10−9 m2/s, whose size increases with the increase of the hot wind speed and temperature. Its magnitude increases with the increase of wind speed and temperature; the drying activation energy of half-ripe rice paper is 6.55 kJ/mol calculated by Arrhenius equation. [ABSTRACT FROM AUTHOR]

This paper studies the pyrolysis mechanisms of Nomex insulation paper in nitrogen and air atmospheres. The Nomex insulation paper is composed of 93% poly (m-phenylene isophthalamide) (PMIA) fibers and 7% inorganic substances based on elemental analysis. Using the thermogravimetry, it is found that the pyrolysis behaviors in nitrogen and air are similar below 770 K, with large discrepancies identified in the temperature range of 770–1073 K. The peak mass loss rate in air is 9 times higher than that in nitrogen. The kinetic analysis shows that the average activation energy (E ) in air is lower than that in nitrogen by 32% when the temperature is higher than 770 K, indicating a lower thermal stability. The PMIA fibers are found decomposing more seriously in air using SEM. Below 770 K, the functional groups of two atmospheres are mainly produced by the breakage of amide bonds and formation of aromatic nitrile. Unlike nitrogen, the organic substances in the solid residue are mostly oxidized at 1073 K in air. Consequently, the maximum productions of H2O, CO2 and CO in air are nearly 5 times higher than those of nitrogen, and the HCN generated during pyrolysis is further oxidized to NOx in air. Combining with the results of Py-GC/MS, it is inferred that the small molecules generated by the degradation of PMIA molecular chains, especially the benzene rings, will experience oxidization reactions in air atmosphere, with large amounts of H2O, CO2, CO and NOx produced. [ABSTRACT FROM AUTHOR]

Organic-rich pulp and paper mill sludge (PPMS) has the potential to become a renewable carbon source for producing alternatives to fossil-based product. In this work, PPMS treated by hydrothermal carbonization (HTC) was investigated based on its pyrolysis properties. The pyrolytic mechanism, kinetics data and product of the sample were studied using TG as well as pyrolysis tests in Py-GC/MS and a bench-scale reactor at 450, 550, and 650 °C. The results show that the thermal decomposition of feedstock is a two-stage reaction. The mean activation energy of the pyrolysis of HTC treated PPMS was estimated as 233.08 kJ/mol, which is higher than that of the pyrolysis of paper sludge reported before. The changes in enthalpies, entropies and Gibbs free energies from the reactants to the activated complex were estimated. The concentration of monocyclic aromatic hydrocarbons in the derived organic liquid fraction shows a positive correlation with the pyrolysis temperature. At 550 °C, the organic liquid fraction reached its highest yield at 13.7% with an oxygen level of 10.7 wt% and a higher heating value of 35.9 MJ/kg. The pyrolytic chars show that a molar ratio of O:C is less than 0.2, which shows potential for use as a carbon sink. • Multi-scale study of pyrolysis behaviour of paper sludge. • Δ H ǂ, Δ G ǂ, and Δ S ǂ of pyrolysis reactions are studied on TG. • Detailed components analysis of the pyrolytic vapor on Py-GC/MS. • Comprehensive evaluation of pyrolysis product from bench-scale reactor. [ABSTRACT FROM AUTHOR]

In this study, practical application for the industrial-scale hydrogen evolution reaction (HER) process is established using sustainable Cu 2 CoSnS 4 embedded in paper-working electrodes. The Cu 2 CoSnS 4 is produced using a solvent-free solid-phase approach. The effect of a wide pH range of electrolytes on working electrodes for hydrogen evolution reactions is also investigated. The Cu 2 CoSnS 4 embedded paper-working electrodes exhibit goodelectrocatalytic activity for hydrogen evolution reaction with low overpotential values of 233, 310, and 261 mV vs RHE at 10 mA/cm 2 in 0.5 M H 2 SO 4 ,1 M KOH, and 1 M PBS, respectively. These designed electrodes exhibit high double-layer capacitance and electrochemical surface area for a wide pH range. In acidic, alkaline and neutral environments, the catalyst-embedded paper electrodes explicit high turnover frequencies of 2.15 s−1, 2.75 s−1, and 2.11 s−1, respectively. The temperature-dependent hydrogen evolution reaction is studied to calculate the activation energy of the cathodic electrode. Utilising chrono-amperometry for about 118 h in an acidic media, which shows that electrodes have a high degree of stability. In comparison to other previously reported work on catalyst-embedded electrodes, the Cu 2 CoSnS 4 embedded paper-working electrodes offer excellentpotential for HER activity across a wide pH range and are suitable for industrial application. • Cu 2 CoSnS 4 embedded paper working electrodes are developed for hydrogen generation. • The electrodes exhibit universal pH hydrogen evolution reaction. • Electrodes shows excellent stability upto 40hr for continuous hydrogen generation. • The electrode displays good stability at current density more than 200 mA/cm2. [ABSTRACT FROM AUTHOR]

The thin-layer drying performance for a typical solid waste (paper towel) was evaluated at hot air temperatures of 90–130 °C (0.5 m/s air velocity) and microwave powers of 200–800 W in a bench-scale microwave combined convective drying setup. Influences of hot air and radiation modes (multi-magnetron and mode stirrer) on the temperature distribution uniformity were examined. The effective moisture diffusivities of sample during pure hot air drying ranged from 6.07 × 10−9 to 1.31 × 10−8 m2/s, while those for pure microwave drying were from 3.54 × 10−8 to 1.52 × 10−7 m2/s. The apparent activation energy of sample in pure hot air drying was estimated as 23.17 kJ/mol, while that for pure microwave drying was 22.64 W/g. The effective moisture diffusivities of sample in combined drying ranged from 5.71 × 10−8 to 2.05 × 10−7 m2/s. The heating uniformity for microwave was improved effectively by the combined drying. The application of the mode stirrers and multi-magnetron radiation modes further improved the microwave heating uniformity. Midilli model can well describe moisture content of paper towel over time. [ABSTRACT FROM AUTHOR]

Thermal annealing is a convenient, low-cost, and versatile route to fine-tune the physicochemical properties of graphene oxide paper (GOP) toward various applications. Therefore, a thorough monitoring of the thermal decomposition of GOP is generally required for a precise and safe adjustment of its properties. From this perspective, thermogravimetry analysis (TG-A) is employed to scrutinize the multi-step thermal decomposition process of GOP under a nitrogen atmosphere. GOP is elaborated from modified hummers graphene oxide (GO). Nonisothermal TG-A is carried out for the as-prepared GOP at different heating rates. Activation energy is assessed for the overall decomposition process by several isoconversional models. Derivative thermogravimetry (D-TG) curves are derived numerically from TG-A data. To find the number of reactions involved, D-TG curves are deconvoluted into individual peaks by the well-known Fraser–Suzuki function. The obtained results show that the thermal decomposition of GOP consists mainly of six reactions: physisorbed water dehydration, rearrangement and elimination of oxygen functional groups, disproportionation reaction, chemisorbed water dehydration, desulfonation, and degradation of the carbon framework. Furthermore, kinetic triplets for each of the individual reactions are figured out by coupling the Vyazovkin nonlinear method with the compensation effect. [ABSTRACT FROM AUTHOR]

Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing temperature of 270 °C. The stronger bonding of wet fibres can be explained by the inter-diffusion of lignin macromolecules with an activation energy around 26 kJ mol−1 after lignin softening. The associated exponential acceleration of diffusion with temperature dominates over other factors such as process dynamics or final material density in setting wet strength. The optimum pressing temperature for dry strength is generally lower, around 200 °C, beyond which hemicellulose degradation begins. By varying the solids content prior to hot-pressing for the TMP sheets, the highest wet strength is achieved for the completely dry web, while no strong correlation was observed for the dry strength.

The diffusion of moisture in the meta-aramid fiber (PMIA) oil-paper insulation system and the thermal decomposition of PMIA insulation paper in different moisture contents were studied via molecular dynamics simulations. The results showed that the PMIA insulation paper had a stronger ability to absorb water molecules than the insulating oil; therefore, water molecules in the insulating oil diffuse to the insulation paper, which further affects the thermal decomposition of the PMIA insulation paper. The activation energy of the water-bearing composite model was 129.96 kJ/mol, which was 5.5% lower than that of the pure PMIA (137.61 kJ/mol). It indicated that moisture could promote PMIA decomposition. The micromechanism of the enhanced thermal decomposition of PMIA with moisture contents could be described as follows: The O–H bond of the water can easily break to generate H atoms and hydroxyl radicals (•OH). The strong activity of H atoms allows it to easily combine with the ammonia base at the end of PMIA to generate NH3. Additionally, the free •OH radical can easily combine with the amido and carbonyl bonds at two ends of PMIA, undergo an oxidation reaction, and generate an oxhydryl. Therefore, it can reduce the chemical stability of the PMIA chain and further drive thermal decomposition. Statistical data on fragments generated by the thermal decomposition of the water-bearing PMIA composite system show that the main products include H2, C/H/O-containing molecules, hydrocarbon molecules, N-bearing molecules, and free radicals. [ABSTRACT FROM AUTHOR]

Frequency Domain Spectroscopy (FDS) is widely used to estimate oil–paper insulation. The high moisture and long aging change the FDS characteristics of the insulating oil–paper, so normalization processing is required. Still, the choice of single activation energy needs further research. This paper studies the FDS characteristic of oil–paper insulation samples with different moisture and aging degrees and improves the traditional temperature correction method. The enhanced Arrhenius model uses the segmented activation energy to make the normalized FDS curve coincide better with the target curve, and the error is reduced. In addition, to verify the method's effectiveness, this paper proposes an iterative correction process. It corrects the tan δ-f curve of the bushing with an aging time of 800 h based on segmented activation energy, and the overall normalization effect is improved. [ABSTRACT FROM AUTHOR]

Highlights • Mechanical properties of waste papers are closely correlated with devolatilization. • Start of devolatilization caused a sudden decrease in relative storage modulus ( E ′ r). • Kinetics of storage modulus change is investigated referring to activation energy. • E ′ r can be predicted with mass loss ratio and CO 2 emission. Abstract This article details a correlation study on early devolatilization behaviors (drying & volatile emission at 25–240 °C) and the change in mechanical properties (expressed by viscoelasticity) of four types of waste papers. The early stage of devolatilization was investigated using the TG-FTIR and mechanical properties using the dynamic mechanical analysis (DMA) method. The results show that the elastic and viscous mechanical properties showed obvious correlations with free and bound water evaporation and volatile emission. The storage modulus (E ′) and loss modulus (E ″) of the papers decreased as temperature increased and at the two important temperatures, namely 100 °C, the start of bound water evaporation, and 150 °C, the start of devolatilization in TG & DTG curves, E ′ showed extrema. Especially the relative storage modulus ( E ′ r) exhibited a sudden decrease at around 150 °C, where the activation energy of thermochemical conversion jumps from low values to high values, indicating the start of devolatilization. CO 2 is the major compound of the volatiles and it is well correlated with E ′ r in exponential function model and can be used as an index for predicting the E ′ r of the waste papers in their early devolatilization stage; while during the drying stage, mass loss ratio can be used to predict E ′ r of the waste papers. [ABSTRACT FROM AUTHOR]

The reuse of waste papers by conversion into valuable carbon materials has received considerable attention for diverse applications such as energy storage and water purification. However, traditional methods for converting waste papers into materials with suitable properties for specific applications are often complex and ineffective, involving consecutive carbonization and activation steps. Herein, we propose a simple one-step microwave (MW)-assisted synthesis for preparing waste paper-derived porous carbons (WPCs) for energy storage and water purification. Through a 30-min synthesis, WPCs with graphitic structure and high specific surface area were successfully produced. The fabricated WPCs exhibited outstanding charge storage capability with a maximum specific capacitance of 237.7 F g−1. Additionally, the WPC demonstrates a high removal efficiency for various dyes, achieving a maximum removal efficiency of 95.0% for methylene blue. The developed one-step MW synthesis not only enables the production of porous carbon from waste paper, but also offers a viable approach to address solid waste management challenges while simultaneously yielding valuable materials. [Display omitted] • Waste paper-derived porous carbons were synthesized by one-step microwave synthesis. • Within 30-min MW synthesis, graphitic and high-surface area WPCs were produced. • WPC exhibits outstanding electrochemical capacitance of 237.7 F g−1. • WPC exhibits high removal of various dyes, with maximum of 95.0% for methylene blue. [ABSTRACT FROM AUTHOR]

In this research, we characterized and discriminated 24 different kinds of writing/printing papers that may or may not have similar compositions by using Thermogravimetric Analysis (TGA). All paper samples were obtained from the local market in and around Chandigarh (Northwest India). Large differences were observed in the estimation of the kinetic parameters of cellulose and hemicellulose. The calculated percentage weight loss and activation energy for Reaction I and II was further used to determine the thermal stability of each sample. Although few differences were observed on visual examination of the samples, significant differences were obtained on the basis of their kinetic parameters. Multivariate analysis was further applied to the results and considerable enhancement of the results was observed. The current study provides 99.28% discrimination among all the possible pairs of paper samples. The technique is cost-effective, involves no sample preparation, consumes less time and provides reproducible results. [ABSTRACT FROM AUTHOR]

• A simple and fast method for loading electrocatalyst Ni 2 B on carbon paper. • A simple process that provides ideas for industrial production. • The solution resistance (Rsol) is only 2.68 Ω after electrochemical impedance testing on Ni 2 B/cp. • The mass of catalyst loaded is only (2–2.5) mg per cm2. In this paper, nickel boride (Ni 2 B) was successfully loaded on carbon fiber paper by electrodeposition and high temperature annealing. The activities of the electrode materials were compared at different deposition currents. The results show that the Ni 2 B/CP-2 electrode with a high surface crystallinity and tetrahedral structure exhibits excellent (OER) activity. Specifically, it can drive a current density of 10 mA cm−2 at a low overpotential of 280.4 mV in 1 M KOH solution, and it has the highest TOF value among these four materials. Furthermore, highly electronegative boron reduces the energy barrier of the nickel metal oxidation reaction and contributes to the charge transfer. [ABSTRACT FROM AUTHOR]

This work investigates which acid can mainly lead to the reduction of alcohols contents in insulating oil during transformer oil-paper insulation aging. In terms of the activation free energy barrier theory, the microscopic mechanisms for the preferential reactions of methanol and ethanol with formic, acetic, naphthenic and stearic acids are analyzed. It is revealed that the decrease in alcohols concentrations in the middle and late stages of transformer oil-paper insulation aging is mainly caused by the reaction between alcohols and naphthenic acid. The results are cross-validated by utilizing the frontier molecular orbital theory and accelerated thermal aging experiments. Additionally, it is observed that methanol is more susceptible to the effect of acids than ethanol in the middle and late stages of aging. The obtained conclusions, in this paper, could provide a theoretical basis for using alcohols in oil as aging indicators to characterize the full-stage aging status of transformer paper insulation. [ABSTRACT FROM AUTHOR]

The pyrolysis of waste disposable paper cups (WDPCs) was investigated using a thermogravimetric analyser coupled with a Fourier transform infrared spectrometer. The activation energies of the pyrolysis reactions were obtained by the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods respectively. The kinetic model was determined by the master plots method. Thermogravimetric results showed that the highest weight loss rate occurred from 345 to 365 °C as the heating rate was increased from 10 to 30 °C min-1, indicating the pyrolysis of cellulosic material in the WDPC. The weight loss between 400 and 500 °C can be attributed to the decomposition of polyethylene. By analysing the FTIR spectra, it was found that the absorbance of all the evolved gaseous products had peaks at 360 °C due to the decomposition of cellulose fibres and the cracking of polyethylene at 485 °C led to the emergence of a second hydrocarbon peak. Ketones were the most abundant condensable organic products and CO2 was the dominating gaseous product, which can also be produced via secondary cracking of the small molecule organics above 400 °C. Kinetic analysis revealed that the average activation energy of the pyrolysis of the WDPC was 153.75 kJ mol-1 from the FWO method and 151.43 kJ mol-1 from the KAS method. The reaction mechanism can be described by the R3 model. [ABSTRACT FROM AUTHOR]

Cellulose material is a dielectric with intricate microscopic relaxation processes due to its complex structure. However, conventional models and curve fitting methods used for tracing and analyzing these processes often fail to capture crucial dielectric information. This paper aimed to extract the Distribution of Relaxation Time (DRT), the most fundamental and effective dielectric information providing the time scale and relative contribution of all microscopic relaxation processes. First, a distributed extended Debye model with infinite branches was constructed based on the microscopic nature of dielectric relaxation. Then, an implicit equation of the DRT function was established, inspired by the mathematical principles of infinite subdivision and summation. To obtain the numeral solution of the DRT function, a regularization method was proposed and validated. Finally, the approach was applied to cellulose insulating paper with varying degradation degrees. The relaxation process with a long time constant played a significant role, and variations during the degradation process were attributed to reduced activation energy. With clear physical interpretation and robust mathematical foundation, our method sheds light on the intricate dielectric relaxation processes in cellulose. This not only enhances the theoretical understanding and practical application of cellulose materials but also provides valuable insights for the analysis and application of other materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Mechanical strength of insulation paper was the key factor for the life of large oil-immersed transformer. To more accurately assess the life of the insulation paper, the aging mechanisms of transformer insulation paper were analysed and a new method using the activation energy was proposed to access the paper's life. Then the life prediction model was defined. Accelerated aging tests of transformer oil-paper insulation samples were executed under different temperatures. According to the test results, the parameters of life prediction model were found out. So, the life of insulation paper under the working condition could be calculated. In the end, an example of insulation paper life evaluation was given to illustrate the effectiveness of this method. [ABSTRACT FROM AUTHOR]

The electrocatalytic hydrogenation of aromatic rings in benzoic acid derivatives has arisen as a notionally engaging substitute for thermal catalysis under mild conditions. However, the utilization of organic solvents and low faradaic efficiency are incompatible with the principles of green chemistry and energy conservation. Herein, bimetallic PtRu supported on carbon paper developed by co-electrodeposition with optimized atomic ratios maintains an inspiring high conversion of 92.9%, high selectivity of 100% and a high faradaic efficiency of 62.2% for the hydrogenation of benzoic acid to cyclohexanecarboxylic acid in an acidic aqueous electrolyte without external H2, which is the best result to date. The optimized electrocatalyst also exhibits outstanding stability and universality for the electrocatalytic hydrogenation of benzoic acid derivatives. In situ Raman results and theoretical calculations prove that the synergistic effect generated by Ru modifying the electronic structure of Pt simultaneously enhances the capture of benzoic acid molecules and interfacial active hydrogen species and lowers the reaction energy barrier. After adsorbing benzoic acid, more accumulation of electrons around the Ru atom reduces the electron density of phenyl, thereby activating the reaction. Meanwhile, the uniform alloy nanoclusters anchored to the carbon paper surface ensure highly efficient electronic transmission and high dispersion of active components, reducing excessive agglomeration. A proton-exchange membrane reactor is also used to certify the potential of the electrocatalytic hydrogenation of benzoic acid derivatives for large-scale application. [ABSTRACT FROM AUTHOR]

Polydiacetylenes (PDAs) are a family of highly conjugated polymers that generate optical response sensitively if exposed to stimuli, the color would change from blue to red. PDAs with reusability and color reversibility are at the central of current research efforts generously. They enhance the electrostatic interaction between cations and the negatively charged carboxylate head groups to increase the rigidity and decrease the energy barrier by introducing Ni2+ into the side chains of PDAs. The amphiphilic 10,12‐pentacosadiynoic acid (PCDA) molecules with the hydrophilic and hydrophobic group are dispersed into Ni2+ aqueous solution and self‐assembled in situ into nanoparticles. Transferring the solution onto a paper base to yield a precisely controlled thickness of PDAs thermal paper. The thermal paper undergoes UV‐induced topological chemical polymerization and further cross‐linking to form stably blue. Because of the reduced energy barrier, red thermal paper after thermal stimulation can undergo color reduction under UV light irradiation. Increasing the photopolymerization time from 5 s to 600 s leads to the rising of the color change temperature from approximately 76.4 °C to 105.4 °C. The polydiacetylene/Ni2+ (PDA/Ni2+) thermal paper can be available for green printing, thermal history recording, and temperature visualization. [ABSTRACT FROM AUTHOR]

Highlights: [•] The combustion of paper sludge could be improved by blending rice straw. [•] There existed significant interaction between rice straw and paper sludge. [•] The interaction improved the thermal decomposition of the blends. [•] The activation energy of initial fuel first decreased and then increased. [•] The average activation energy was the minimum by blending 80% rice straw. [Copyright &y& Elsevier]

Accurate determination of the thermal properties of cellulose is of particular significance in studying the mechanism of cellulosic cigarette paper combustion. This paper probes into the influence of four kinds of potassium carboxylates on the thermal degradation kinetics and the heat properties of cigarette paper through simultaneous thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC) measurement under air atmosphere. Reduced mass loss and mass loss rate, and increased solid residue for samples containing four potassium salts implied that potassium carboxylates may retard the formation of levoglucosan and volatiles by inhibiting the depolymerization reaction and simultaneously accelerate char formation by catalyzing the dehydration reaction. Kinetic parameters were analyzed based on three non-isothermal models available in literature. The results indicated that three modeling methods exhibit good consistency. A global activation energy range of 106–155 kJ mol −1 was proposed for cigarette paper with potassium carboxylates. The four potassium salts studied considerably reduced the activation energy in the following descending order: potassium 1,2,3,4-butane tetracarboxylate (PBTCA) > citrate > gluconate > ascorbate. The heat properties of cigarette paper were also determined by integrating the DSC curves. The results demonstrated that both cellulose degradation and char oxidation have strong exothermic peaks. Cigarette paper samples with potassium salts have lower exothermic cellulose degradation process and higher exothermic char oxidation process, which were further confirmed by greater differences as the amounts of salt citrate or PBTCA increased. [ABSTRACT FROM AUTHOR]

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Highlights: [•] The pyrolysis kinetics of cigarette paper was investigated. [•] Potassium salt KHCO3 decreased the pyrolytic peak temperature significantly at 107°C. [•] The activation energy range of 134–252kJmol−1 for cigarette paper cellulose was proposed. [•] Four studied potassium salts in the cigarette paper decreased the activation energy remarkably. [•] Both potassium cations and anions are responsible for the catalyzing effect on the pyrolysis kinetics of cigarette paper. [ABSTRACT FROM AUTHOR]

1‐Methylcyclopropene (1‐MCP) has been shown to be a suitable inhibitor of ethylene production in fruit and vegetables during preservation and distribution. In this study, a 1‐MCP controlled‐release system on coated paper was produced using shellac as the coating material. The effect of humidity and temperature on the release of 1‐MCP from the coated paper was investigated using a dynamic sorption system (DVS) with stepwise humidity changes (initial 20% relative humidity (RH) for 2 h, then increased to 40%, 50%, 60%, and 80% RH for 2 h, respectively). The release rate kinetic data were simulated using an Avrami equation with a mechanism release number n of 1.26. The results showed that the dynamic release of 1‐MCP from the coated paper was mainly affected by humidity, for which the release rate constant could be correlated with moisture concentration in humid air. The highest humidity condition (80% RH) resulted in the highest apparent activation energy of 46.8 kJ/mol. The effect of 1‐MCP coated paper on apple storage was evaluated by measuring the ethylene production rate, flesh firmness, and titratable acidity (TA) of apple. Ethylene production rates of apple were significantly affected with 1‐MCP coated paper. The values were 0.22 nL/g FW/h at 50 mg of 1‐MCP powder and 44.7 nL/g FW/h at 0 mg of 1‐MCP powder after 15 days at 4°C and 15 days at 20°C. The other properties of apple such as flesh firmness and TA also indicated that 1‐MCP coated paper could delay fruit softening during storage time. Based on these results, the release of 1‐MCP could be controlled by coating paper with shellac solution and promising to produce functional packaging for fruit. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compared to N 2 , the pyrolysis of MSW and PS was more complete under CO 2 atmosphere. • The evolution of six typical pyrolysis products were illustrated by TG-FTIR. • MgO could act as a catalyst to promote the pyrolysis reaction of blends. • Through DAEM, the activation energy in two stages were about 170 and 300 kJ/mol. In order to explore a harmless and resource-based way to treat municipal solid waste (MSW) and paper sludge (PS), the co-pyrolysis MSW and PS was studied in this paper. Firstly, MSW and PS had the lower residue mass, and MSW had higher pyrolysis index under CO 2 atmosphere, compared with the one under N 2 atmosphere. Hence, the CO 2 was used as the carrier gas in the following study. Secondly, under CO 2 atmosphere, the co-pyrolysis of MSW and PS with and without MgO were researched. With the increasing of PS ratio, the pyrolysis performance of the blends decreased constantly. MgO act as catalyst could improve the pyrolysis characteristic index of the blends. However, MgO was an inorganic salt and it would affect the synergistic effect of MSW and PS. The curves of online evolutions of all the gas products and the functional groups had an obvious peak at around 500 ℃. The activation energy of the blends in the first step (<600 ℃) were around 170 kJ/mol and reached more than 300 kJ/mol of the second step (600−1000 ℃). In addition, the adding of MgO could decrease the activation energy of MSW, 50M50P and PS. Finally, 50M50P-M was suitable for treating more sludge. And these results could offer some referential information for designing and optimizing the co-pyrolysis technology for MSW and PS. [ABSTRACT FROM AUTHOR]

Activation energy is popularly used for the estimation of remaining life of transformer insulation. It is defined as the average rate of all reactions that happen with cellulose. Existing literature shows that the activation energy of oil–paper insulation can be obtained from polarization depolarization current (PDC) and return voltage measurement (RVM) data that are measured at a specific temperature. It is practically difficult to ensure the same measurement temperature for both PDC and RVM data. On the other hand, PDC data and its analysis get influenced by de-trapping current. This de-trapping current is generated by ionic charge carriers that get freed from trap sites during PDC measurement process. Formation of these trap sites is related to physical, chemical reactions that happen at oil–paper interface. This paper proposes a methodology which uses de-trapped charge, dislodged from deep and shallow traps, to assess insulation condition and for the prediction of activation energy. Thus, eliminating the need of RVM data. The proposed method is tested using data collected from various real-life in-service transformers. [ABSTRACT FROM AUTHOR]

• Kinetics of paper-laminated phenolic PCB pyrolysis was explored based on the TGA results. • The kinetic parameters were estimated by isoconversional model-free kinetic approaches. • Variation of apparent activation energy indicated the mechanism change during the pyrolysis. • Discrete and gaussian DAEMs were implemented to describe the kinetics of pyrolysis process. • Good agreement was observed between experimental results and data predicted by the DAEMs. This work explores the pyrolysis characteristics and kinetic behavior of paper-laminated phenolic printed circuit boards (PLP-PCBs) using thermogravimetric analysis under non-isothermal linear heating programs. The initial estimation of the kinetic parameters during the pyrolysis was obtained from the analysis of the experimental data by three isoconversional kinetic models, i.e. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) integral methods, as well as the Friedman differential method. For all three methods, the apparent activation energy exhibited a strong dependence on the degree of the reaction conversion. To allow for the complexity of the reactions involved in the PLP-PCB pyrolysis, two distributed activation energy models (DAEMs) with a first-order reaction function were derived by assuming the discrete and multi-Gaussian distributions for the activation energies. A six pseudo-component Gaussian DAEM was able to accurately describe the PLP-PCB pyrolysis. By applying the discrete DAEM algorithm, the pyrolysis of PLP-PCB could be precisely characterized by 37 dominating reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, an analysis of co-pyrolysis municipal solid waste and paper sludge with additive (MgO) were investigated by TG-FTIR and Py-GC/MS. The proportions of paper sludge in the blends were 10%, 30% and 50%, respectively. The pyrolysis characteristics, the yields of pollutants (CO, SO 2 , NO, HCl) and CO 2 , the products and chemical composition, the kinetic behaviors and the distribution activation energy model were investigated. After adding paper sludge, the sums of pollutants reduced, the amount of aliphatic hydrocarbons decreased and oxygenates compounds increased. After adding MgO, the results showed that the residue mass decreased, the emission of pollutants reduced, the ratio of aliphatic hydrocarbons became larger, the ratio of oxygenates compounds became smaller, and the activation energy reduced. According to the beforementioned results, the 30% percentage of paper sludge in the mixture with MgO might be the most suitable ratio for co-pyrolysis. [ABSTRACT FROM AUTHOR]

Pyrolysis characteristics of Tetra Pak, a paperboard-polyethylene-aluminium foil, were investigated in this study with a focus on the synergistic effect between its individual components. Scanning electron microscopy analysis indicated that molten LDPE coating on cellulose surface led to suppression on mass and heat transfer and the increased activation energy of pyrolysis reaction. Samples of individual components and simulated Tetra Pak packaging were pyrolyzed in a thermogravimetric analyzer at various heating rates. Synergistic effect between cellulose and LDPE on E a and the formation of characteristic products are investigated: Kinetic analysis showed that the cellulose decomposition peak in the simulated mixture exhibited a higher E a than that of pure cellulose at each conversion rate. For LDPE, the free radicals formed from cellulose pyrolysis enhanced the degradation of plastic polymers, resulting that E a of its decomposition peak in the mixture being lower in comparison to pure LDPE, with a discrepancy of around 16–27 kJ·mol−1. The formation of characteristic products including levoglucosan, furfural, 5-hydroxymethylfurfural, and alkanes from pyrolysis of cellulose and LDPE mixture with different mass ratios was further investigated in a micro-pyrolyzer. The results suggested that synergistic effects and physical barrier existed during fast pyrolysis between cellulose and LDPE. The extent of the synergy effect depended on the proportion of cellulose and LDPE in the mixture. • Synergistic effect was investigated during pyrolysis of Tetra Pak. • Molten LDPE coating on cellulose increases E a of cellulose pyrolysis. • The extent of synergy effect depends on the proportion of cellulose and LDPE. [ABSTRACT FROM AUTHOR]

Municipal papers and polyethylene terephthalate (PET) wastes are primary constituents of municipal solid waste (MSW) which necessitates effective disposal. Co-pyrolysis is an efficient transformation technology for the production of valuable gas and liquid fuels. Therefore, co-pyrolysis characteristics, kinetics, gas and liquid products of cellulose and PET mixtures were investigated in a two-stage reactor by multiple characterizations coupling with deep learning approach. The results indicated that there exhibited positive interaction for cellulose and PET co-pyrolysis in terms of mass difference (δ m) and mass loss rate difference (δ r) between experimental and calculated values. The thermal decomposition process and synergistic effects (δ m and δ r) were accurately predicted by deep learning approaches (R 2 =0.9823–0.9993) using temperature, catalyst, mixing ratio and heating rate variables. Feature importance revealed that the temperature, catalyst, heating rate and mixing ratio were in the descending order to affect the remaining mass from TG curves. And the temperature played a predominant role in synergistic effects. The Flynn-Wall-Ozawa (FWO) method was more suitable for fitting the pyrolysis process to obtain activation energy (E a) with higher R 2 (0.94714–0.99640) compared with Kissinger-Akahira-Sunose (KAS) method. When the mixing ratio of cellulose and PET was 1:1, the E a was significantly reduced to 80.73 KJ/mol, and further reduced to 73.04 KJ/mol by introducing the catalyst, as compared to E a of individual cellulose (178.95 KJ/mol) and PET (198.34 KJ/mol). Co-pyrolysis of cellulose and PET led to a reduction of carbohydrates, furans, alcohols, ketones, and phenols, while the content of acids was remarkably increased which was consistent with the observation in FTIR that the absorption peak of C＝O became sharp and strong. The introduction of ZSM-11 resulted in an increase in aromatics and a decrease in acids content owing to aromatization and deoxygenation. This work is expected to offer beneficial guidance for the efficient disposal of MSW and the application of deep learning methods. [Display omitted] • The interactive pathway for catalytic co-pyrolysis of cellulose and PET was proposed. • The activation energy reached the lowest 73.04 KJ/mol when the mixing ratio was 1:1. • Optimized convolutional neural network predicted synergistic effects with R 2 > 0.99. • Feature importance for TG was temperature > catalyst > heating rate > mixing ratio. [ABSTRACT FROM AUTHOR]

In this study, through orthogonal experiments design, the influences of ultrasonic pretreatment (frequency, power and treatment time) on co-pyrolysis and catalytic pyrolysis of municipal solid waste and paper mill sludge were explored. The differential thermogravimetry curves became steeper and the peak values were larger after pretreatment, which made the pyrolysis reaction rapidly and the volatile separated out timely. However, the change of pyrolysis characteristics was not obvious after adding MgO. The catalytic effect of MgO increased with the increase of sludge ratio. After pretreatment, the average activation energy of the samples had an overall increasing trend, but the change was small. MgO had a decreasing effect on activation energy, and with the increasing proportion of sludge the degree of reduction became significant. In addition, high ultrasonic frequency had a negative effect on reducing activation energy. • Study on the co-pyrolysis of municipal solid waste and paper mill sludge. • The differential thermogravimetry curves became steeper after pretreatment. • Distributed activation energy model was used to calculate the kinetic parameters. • The average activation energy had a minor increasing trend after pretreatment. • High ultrasonic frequency had a negative effect on reducing activation energy. [ABSTRACT FROM AUTHOR]

Cellulose is the main component of transformer insulating paper. In this paper, the pyrolysis mechanism of cellulose is studied by means of computational chemistry. This study is aimed at exploring the generation process of the methanol from cellulosic insulating paper at the atomic level. A simulation scheme of cellulose pyrolysis with detailed reaction pathways for methanol production has been obtained that is not readily accessible by experiments. The molecular dynamics method based on reactive force field (ReaxFF) is adopted to simulate the pyrolysis of cellobiose. A model composed of 40 cellobioses simulated at 500–3000 K was established, and the force biased monte-carlo is mixed into ReaxFF to make it closer to the actual situation and ensure the reliability. The result reveals that the –CH2– group from the C5 (or C 5 ′ ) group in cellobioses grabbed the nearby H atom to form methanol. In the pyrolysis process of cellobioses, methanol is stable at the early stage but unstable even disappeared in the later stage. The pre-exponential factor A and activation energy Ea of the ReaxFF-MD simulation are consistent with previous experimental results. Thus, this study provides an effective theory of the methanol as an indicator to evaluate the aging condition of cellulosic insulating paper in the early stage at the atomic level. [ABSTRACT FROM AUTHOR]

Although degradation of iron gall ink containing paper has been scientifically studied for almost 250 years, we still do not have a good understanding of the kinetics of the process. While many studies focussed on model samples to avoid the inhomogeneity of real historic samples or the need for sampling, this research was conducted on a selection of real documents. Accelerated degradation experiments were performed at six combinations of temperature and relative humidity (RH) in the intervals 50–80 °C/20–80% RH. The analytical methods were optimised such that sample consumption was minimised and errors and uncertainties were evaluated. The results show that the rate of degradation, measured as change in the degree of polymerisation of cellulose in paper beneath ink, can be described in Arrhenius terms, and that the apparent activation energy for the process depends on the moisture content in the material. The variation is consistent with the process of hydrolysis becoming less prominent at lower moisture content values, although the results indicate that hydrolytic degradation predominates during natural ink-induced degradation. In the context of the historic samples used in the study, the presence of ink accelerated the degradation of paper by a constant factor of 1.59 in comparison to paper without ink, across the range of experimental T and RH. This indicates that a dose-response function could be developed for ink-induced degradation of paper. [ABSTRACT FROM AUTHOR]

With rising concern for environmental protection, the use of ozone has been increasingly studied in the pulp and paper industry. Feasible models for efficient quality prediction and process control are in high industrial demand. In this study, the reaction kinetics of delignification and viscosity during the ozone bleaching process (OBP) of low-consistency hardwood pulp (LCHP) are explored using exponential and zero-order response models, respectively. The effects of ozone dose, reaction temperature, reaction time, and pH on the changes in residual lignin content and pulp viscosity were analyzed. The corresponding kinetic parameters, such as the reaction order, rate constant (k), and activation energy (E), were also obtained. The models suggest that temperature should be one of the most significant factors affecting the effectiveness of the OBP system. The strategy to improve the OBP selectivity is based on reducing the reaction temperature while increasing the ozone concentration and pH in the reaction system. [ABSTRACT FROM AUTHOR]

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The oil-impregnated pressboard of the transformer is an important part of the oil paper insulation system． The frequency domain dielectric response curve is affected by the test temperature and the internal moisture content of the pressboard． In order to study the influence of different factors on the accuracy of the calculation, a number of oil-impregnated pressboard samples with different moisture content were firstly prepared under the laboratory conditions． Temperature-dependent dielectric spectroscopy test was implemented for samples with different moisture content． Secondly, according to the test results, a spectral translation method based on characteristic frequency points was proposed． The temperature dielectric spectra of different moisture were calculated by translation． At last, based on the frequency domain spectrum translation results of oil-impregnated pressboard with different moisture content, the relaxation time activation energy will affect the shift trend of temperature dielectric spectroscopy． The activation energy of the oil-impregnated pressboard’s relaxation time increases exponentially with the rise of moisture content． To better combine the relationship between the frequency conversion method and the effect of the moisture content on the activation energy, according to the experimental results, the activated energy and moisture content of the oil-impregnated pressboard were quantitatively characterized． The proposed frequency translation model is optimized, and the effectiveness of the optimal translation method is verified． [ABSTRACT FROM AUTHOR]

By using thermogravimetric analysis (TGA), the effects of different additives (MgO, Al 2 O 3 and ZnO) on the pyrolysis characteristics and activation energy of municipal solid waste (MSW), paper sludge (PS) and their blends in N 2 atmosphere had been investigated in this study. The experiments resulted that these additives were effective in reducing the initial temperature and activation energy. However, not all the additives were beneficial to reduce the residue mass and enhance the index D . For the different ratios of MSW and PS, the same additive even had the different influences. The catalytic effects of additives were not obvious and the pyrolysis became difficult with the increase of the proportion of PS. Based on all the contrast of the pyrolysis characteristics, MgO was the best additive and 70M30P was the best ratio, respectively. [ABSTRACT FROM AUTHOR]

Frequency domain spectroscopy (FDS) is widely used to diagnose the condition of transformer oil–paper insulation. However, FDS measurements are highly temperature dependent. The master curve technique is the most common method to remove the temperature effect on FDS, but the reliability of this method is largely dependent on the value of the activation energy, which can be affected by moisture content and thermal degradation degree. To understand the effects of these two factors on the activation energy, FDS measurements at different temperatures were performed on oil‐impregnated pressboards with different thermal degradation degrees and moisture contents. The activation energies of the pressboards were calculated using the Arrhenius equation. Results show that they vary between 0.88 and 1.06 eV along with thermal degradation degree and moisture. The two‐way ANOVA indicates that the effects of these two factors on activation energy are not significant at 95% confidence level when the degree of polymerisation (DP) changes from 415 to 1300 and when the moisture does not exceed 4%. The average activation energy (0.95 eV) can be utilised to generalise the Arrhenius equation to better eliminate the temperature effects. Finally, FDS measurements on a model transformer are performed to verify the effectiveness of the proposed technique. [ABSTRACT FROM AUTHOR]

This work reports on deoxygenation thermokinetics involved in preparing freestanding deoxygenated graphene oxide paper (DGOP) and the degree of deoxygenation-electrical transport correlation. The differential scanning calorimetry (DSC) and thermomechanical analyzer (TMA) for dimensional change study revealed that the manifestation of graphene oxide paper (GOP) into DGOP is associated with the activation energy of 153.8 kJ/mol with releasing gaseous moieties in the range of 210–230 °C. With variation in deoxygenation temperature ranging from 50 to 250 °C, DGOP is altered from dark brown to black, indicating the thermal reduction of DGOP. Upon increasing the annealing temperature, the hydrophobicity and electrical conductivity of DGOP are significantly increased. DGOP-250 exhibited superhydrophobicity and electrical conductivity of 102.2° and 4.5 S/cm, respectively. Understanding the underlying controlled-thermokinetics in converting GOP into DGOP with DSC and TMA helps in fine-tuning the structural modification associated electrical transport and hydrophobicity, which is desirable for practical applications. [Display omitted] • Freestanding graphene oxide paper (GOP) preparation via vacuum-assisted filtration • GOP converts into DGOP with the activation energy of 153.8 kJ/mol • Deoxygenation is prominent in the range of 210-230 °C as per DSC and TMA study • Deoxygenation temperature (50 to 250 °C) altered DGOP from dark brown to black • DGOP-250 showed hydrophobicity and electrical conductivity of 102.2° and 4.5 S/cm [ABSTRACT FROM AUTHOR]

As the temperature gradient always exists in the insulation of power equipment, the influence of temperature gradient on oil-impregnated paper insulation is studied by experiments and simulation. It's found that in the both single-layer and double-layer structures, the heterocharges always appear near the lower temperature electrode, and increase with the enhancement of temperature gradient and field stress, resulting in more considerable field distortion. However, there are more heterocharges in the single-layer samples while the field distortion is more severe in double-layer samples. Numerical simulations were carried out to investigate the mechanism of temperature gradient effect. It is indicated that the space charge accumulation is mainly due to the temperature dependence of the charge injection and conduction. The behavior of interface charges can be well described by assuming an energy barrier for charge transportation at the interface. [ABSTRACT FROM AUTHOR]

The correct form is 5 HT ht Graph Fourth error (serious) The equation (21) in [[1]] is as follows 6 HT ht Graph Equation (6) is a dimensionless equation presented in [[1]] after the non-dimensionalization in equation (17) in [[1]]. [Extracted from the article]