Thermogravimetric pyrolysis kinetics study of tobacco stem via multicomponent kinetic modeling, Asym2sig deconvolution and combined kinetics

Characterizing novel cellulosic fibers extracted from Vicia faba plant waste stems as a promising reinforcement for applications in sustainable textile and lightweight biocomposites

Plant fibers (like cotton, jute, etc.) provide essential materials for human civilization. Here, we study natural fibers (NFs) derived from the Vicia faba (Vf) plant stems, which were examined in this research to assess their potential as a sustainable substitute in plant fiber-based industries. Their previously unexplored morphological, physicochemical, and thermomechanical characteristics are the main focus of the research. X-ray diffraction (XRD), scanning electron microscopy, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy, and Weibull distribution (WD) analysis were among the methods used. According to XRD, Vf fibers (VfFs) feature crystallites that measure 2.98 nm and have a crystallinity index of 60 %. VfFs showed a failure strain of 1.47 ± 0.40 %, a Young's modulus of 4.15 ± 0.36 GPa, and an average tensile strength of 56.37 ± 13.33 MPa. The maximum likelihood method of statistical WD analysis was used to examine these properties. TGA revealed that VfFs had an activation energy of 89.40 kJ/mol and are thermally stable up to 352 °C. These findings support an environmentally friendly approach to material enhancement by highlighting the potential of VfFs for usage in lightweight biocomposites and their applications in the textile industry.

Enhancing Syagrus romanzoffiana lignocellulosic fibers' properties by ecological treatment with sodium bicarbonate for applications in sustainable lightweight biocomposites

Investigating the fascinating world of natural fibers, where Syagrus romanzoffiana fibers (SrFs) are promising substitutes for glass and synthetic fibers in composite materials, is more than interesting. The improvement of SrFs through an environmentally friendly treatment employing sodium bicarbonate (NaHCO₃) at different concentrations (5 %, 10 %, 20 %, and 30 % by weight) over various durations (24, 72, and 168 h) is the subject of this study. The objective is to provide a sustainable and economical approach to enhancing fiber characteristics. Comparisons were made between treated and untreated fibers and fibers from semi-arid and humid regions to evaluate geographical influences. Key findings include considerable enhancements in tensile properties: a 58 % rise in Young's modulus and a 69 % rise in traction stress for fibers treated with 20 % NaHCO₃ for 72 h. The stretching at fracture of these treated fibers was measured at 1.04 ± 4.49 %. The treated fibers also showed an increased crystallinity index of 71.61 % and a crystal size of 2.38 nm. Fourier-transform infrared spectroscopy revealed the chemical modifications from the treatment. Thermogravimetric analysis (TGA) indicated thermal stability up to 327 °C and a kinetic activation energy of 53.84 kJ/mol, compared to 62.72 kJ/mol for untreated fibers. The study highlights an environmentally friendly approach to material development by showcasing the potential of treated SrFs in lightweight biocomposite applications. This study provides valuable information on the TGA/pyrolysis of SrFs at 10 °C/min for potential bioenergy production, including assessing environmental impact, opportunities concerning sustainable resource management, and integration with other renewable energy systems.

Extracting and characterizing of a new vegetable lignocellulosic fiber produced from C. humilis palm trunk for renewable and sustainable applications

Research on natural fibers as greener substitutes for synthetic ones has surged in response to the growing need for sustainable materials. An underutilized natural resource, Chamaerops humilis trunk (ChT), is the subject of this study's extraction and characterization process. The work examines these fibers' possible uses in biocomposites by examining their structural, physicochemical, and mechanical characteristics. Numerous characterization techniques were used to evaluate ChT fibers (ChTFs) thoroughly, including density measurement, diameter determination, analysis of the fibers' moisture content, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermal analysis, water absorption tests, and tensile testing. Experimental results show that ChTFs possess an average density of 0.97 g/cm3, an average diameter of 562 ± 60 μm, a moisture regain ranging from 7.94 to 8.63 %, an average linear density of 9.338 Tex, heat resistance to 225 °C and a mean traction resistance of 45.08 ± 9.92 MPa. Such findings underscore the significance of comprehending the ChT's mechanical characteristics to enhance fiber-reinforced composites and explore their possible uses in the textile sector besides their promising reinforcements in biocomposites and as a source of biomass for renewable bioenergy.

Effective waste management through Co-pyrolysis of EFB and tire waste: Mechanistic and synergism analysis

Driven by the need for solutions to address the global issue of waste accumulation from human activities and industries, this study investigates the thermal behaviors of empty fruit bunch (EFB), tyre waste (TW), and their blends during co-pyrolysis, exploring a potential method to convert waste into useable products. The kinetics mechanism and thermodynamics properties of EFB and TW co-pyrolysis were analysed through thermogravimetric analysis (TGA). The rate of mass loss for the blend of EFB:TW at a 1:3 mass ratio shows an increase of around 20% due to synergism. However, the blend's average activation energy is higher (298.64 kJ/mol) when compared with single feedstock pyrolysis (EFB = 257.29 kJ/mol and TW = 252.92 kJ/mol). The combination of EFB:TW at a 3:1 ratio does not result in synergistic effects on mass loss. However, a lower activation energy is reported, indicating the decomposition process can be initiated at a lower energy requirement. The reaction model that best describes the pyrolysis of EFB, TW and their blends can be categorised into the diffusion and power model categories. An equal mixture of EFB and TW was the preferred combination for co-management because of the synergistic effect, which significantly impacts the co-pyrolysis process. The mass loss rate experiences an inhibitive effect at an earlier stage (320 °C), followed by a promotional impact at the later stage (380 °C). The activation energy needed for a balanced mixture is the least compared to all tested feedstocks, even lower than the pyrolysis of a single feedstock. The study revealed the potential for increasing decomposition rates using lower energy input through the co-pyrolysis of both feedstocks. These findings evidenced that co-pyrolysis is a promising waste management and valorisation pathway to deal with overwhelming waste accumulation. Future works can be conducted at a larger scale to affirm the feasibility of EFB and TW co-management.

Extracting and characterizing novel cellulose fibers from Chamaerops humilis rachis for textiles' sustainable and cleaner production as reinforcement for potential applications

New cellulose (CL) fibers are derived from Chamaerops humilis (Ch) rachis. They play an essential role in various industries to produce environmentally friendly products as an alternative to enhancing and strengthening lightweight composites, such as dashboards automotive. Distinctive properties of Ch fibers (ChFs) were determined by extracting fibers from dwarf palm plant branches using anaerobic analysis. This search comprehensively studies morphological, physical, mechanical, and thermal characteristics and water absorption testing. The fiber diameter was 241.23 ± 34.77 μm, while the obtained linear density and density were 13.71 ± 0.57 Tex and 0.801 ± 0.05 g/cm3, respectively. The moisture content was 8.5 %, and the moisture regain was 9.29 %. Scanning electron microscopy images showed the fibers and smooth and rough surfaces. The thermogravimetric analysis demonstrated the maximum degradation of 352 °C, thermal stability of 243 °C, and the kinetic activation energy reached (79.78 kJ/mol). X-ray diffraction proves the availability of CL, with a crystallinity index = 68.38 % and crystal size = 2.92 nm. Fourier transform infrared succeeded in detecting functional groups and chemical compounds of fibers. The fibers exhibited a tensile stress of 110.85 ± 77.08 MPa, an elongation at a break rate of 2.29 ± 1.27 %, and Young's modulus of 6.05 ± 3.9 GPa. The maximum likelihood method (2P-Weibull distribution) was employed to examine the distribution of mechanical properties of fibers. According to the results above, new ChFs are an excellent reinforcement for elaborating fiber-reinforced biocomposites.

Quantitative analysis of pyrolysis characteristics and chemical components of tobacco materials based on machine learning

To investigate the quantitative relationship between the pyrolysis characteristics and chemical components of tobacco materials, various machine learning methods were used to establish a quantitative analysis model of tobacco. The model relates the thermal weight loss rate to 19 chemical components, and identifies the characteristic temperature intervals of the pyrolysis process that significantly relate to the chemical components. The results showed that: 1) Among various machine learning methods, partial least squares (PLS), support vector regression (SVR) and Gaussian process regression (GPR) demonstrated superior regression performance on thermogravimetric data and chemical components. 2) The PLS model showed the best performance on fitting and prediction effects, and has good generalization ability to predict the 19 chemical components. For most components, the determination coefficients R 2 are above 0.85. While the performance of SVR and GPR models was comparable, the R 2 for most chemical components were below 0.75. 3) The significant temperature intervals for various chemical components were different, and most of the affected temperature intervals were within 130°C-400°C. The results can provide a reference for the materials selection of cigarette and reveal the possible interactions of various chemical components of tobacco materials in the pyrolysis process.

Co-pyrolysis of sewage sludge and waste tobacco stem: Gas products analysis, pyrolysis kinetics, artificial neural network modeling, and synergistic effects

This research comprehensively investigates the co-pyrolysis of sewage sludge (SS) and waste tobacco stem (WTS). Various SS and WTS ratios (1:0, 0.75:0.25, 0.50:0.50, 0.25:0.75, and 0:1) were tested over a range of heating rates (30 °C to 800 °C). Apparent activation energies were calculated using model-free methods, and the co-pyrolysis mechanism was described with the master plot method. Results suggest that SS and WTS co-pyrolysis follows power-law models (P3, P4). Among blends, S75W25 exhibited optimal synergy, with the lowest activation energy required for the pyrolysis reactions and inhibits CO2 emissions. S75W25's pyrolysis gas primarily contained acids (e.g., ethylxanthogenacetic acid, acetic acid), hydrocarbons (e.g., supraene, cyclopropyl carbinol), and other compounds (e.g., CO2, pyrazine, pyridine, indole). ANN was utilized to forecast the temperature-mass loss relationships in co-pyrolysis, with the optimal model being ANN21, yielding a high correlation coefficient (R2 = 0.99999). This study offers guidance for the efficient utilization of waste SS and WTS.

Co-pyrolysis of biomass and polyethylene: Insights into characteristics, kinetic and evolution paths of the reaction process

Investigation on the distribution and mechanism of co-pyrolysis products is vital to the directional control and high-value utilization of agriculture solid wastes. Co-pyrolysis, devolatilization, kinetics characteristics, and evolution paths of corn stalk (CS) and low-density-polyethylene (LDPE) were investigated via thermogravimetric experiments. The co-pyrolysis behaviors could be separated into two stages: firstly, the degradation of CS (150- 400 °C); secondly, the degradation of CS (400- 550 °C). The devolatilization index (DI) increased with the addition of LDPE. Furthermore, a combination of devolatilization chemical analysis with product analysis to analyze the intrinsic mechanism during co-pyrolysis. The results indicated that the yield of alkanes and olefin in gas products increased with the addition of LDPE. Additionally, LDPE pyrolysis maybe abstract hydrogen from CS pyrolysis and evolved into hydrogen, methane, and ethylene. Further, the co-pyrolysis kinetic parameters were computed by using model-free isoconversion methods, which showed promotion of CS pyrolysis and the reduced activation energy. All the activation energy were declined, which indicated a "bidirectional positive effect" during co-pyrolysis. The mean activation energy of P-cellulose (P-CE), P-hemicellulose (P-HM), P-lignin (P-LG), and LDPE decreased by 23.49 %, 12.89 %, 15.36 %, and 27.82 %, respectively. This study further proves the hydrogen donor transfer pathway in the co-pyrolysis process of CS and LDPE, providing theoretical support for the resource utilization of agricultural solid waste.