Pyrolysis of oil extracted safflower seeds: Product evaluation, kinetic and thermodynamic studies

Thermal Decomposition of 2-Cyclopentenone

The thermal decomposition of 2-cyclopentenone, a cyclic oxygenated hydrocarbon that occurs in the pyrolysis of biomass, has been studied in a combined experimental and theoretical approach. Gas-phase pyrolysis was performed at temperatures ranging from 1000 to 1400 K in a pulsed, microtubular reactor. Products were identified by FTIR spectroscopy following their isolation in a low-temperature argon matrix. The following products were identified: carbon monoxide, ketene, propenylketene, vinylacetylene, ethylene, propene, acrolein, acetylene, propyne, and propargyl radical. Computational results identify three different decomposition channels involving a H atom migration, and producing prop-2-enylketene (Pathway 1), prop-1-enylketene (Pathway 2), and a second conformation of prop-2-enylketene (Pathway 3). A fourth decomposition pathway involves simultaneous rupture of two C-C bonds forming a high energy cyclopropenone intermediate that further reacts to form ethylene, acetylene, and carbon monoxide. Finally, a fifth pathway to the formation of acrolein and acetylene was identified that proceeds via a multistep mechanism, and an interconversion from 2-cyclopentenone to 3-cyclopentenone was identified computationally, but not observed experimentally.

Pyrolysis and Physicochemical, Thermokinetic and Thermodynamic Analyses of Ceiba aesculifolia (Kunth) Britt and Baker Waste to Evaluate Its Bioenergy Potential

Ceiba aesculifolia is an important species in Mexico that generates significant amounts of biomass waste during its exploitation, which can be utilized to produce energy. This study presents the characterization of this waste based on chemical (proximal and elemental) and thermal analyses (TGA-DTG) at different heating rates (β = 10-30 °C/min (283-303 K/min)) in the presence of nitrogen and in a temperature range of 25-900 °C. Kinetic parameters were calculated and analyzed as well. Activation energy (Ea) and the pre-exponential factor (A) were determined using the Friedman (132.03 kJ/mol, 8.11E + 10 s -1), FWO (121.65 kJ/mol, 4.30E + 09), KAS (118.14 kJ/mol, 2.41E + 09), and Kissinger (155.85 kJ/mol, 3.47E + 11) kinetic methods. Variation in the reaction order, n (0.3937-0.6141), was obtained by Avrami's theory. We also calculated the thermodynamic parameters (ΔH, ΔG, ΔS) for each kinetic method applied. The results for Ea, A, n, ΔH, ΔG, and ΔS show that this biomass waste is apt for use in pyrolysis. Moreover, the moisture (<10%), ash (<2%), volatile material (>80%), and HHV (>19%) contents of C. aesculifolia allowed us to predict acceptable performance in generating energy and fuels. Finally, infrared spectroscopy analysis (FT-IR) allowed us to identify important functional groups, including one that belongs to the family of the aliphatic hydrocarbons.

Gasification of biomass for syngas production: Research update and stoichiometry diagram presentation

Gasification is a thermal process that converts organic materials into syngas, bio-oil, and solid residues. This mini-review provides an update on current research on producing high-quality syngas from biomass via gasification. Specifically, the review highlights the effective valorization of feedstocks, the development of novel catalysts for reforming reactions, the configuration of novel integrated gasification processes with an assisted field, and the proposal of advanced modeling tools, including the use of machine learning strategies for process design and optimization. The review also includes examples of using a stoichiometry diagram to describe biomass gasification. The research efforts in this area are constantly evolving, and this review provides an up-to-date overview of the most recent advances and prospects for future research. The proposed advancements in gasification technology have the potential to significantly contribute to sustainable energy production and reduce greenhouse gas emissions.

Auxiliary effect of CO2 on pyrolysis of oily sludge

The efficient recovery and conversion of energy in oily sludge has great prospects. In this article, the main objective is to investigate the impact of the addition of CO₂ during the pyrolysis of oily sludge on energy recovery and conversion by thermogravimetric analysis (TGA) and compare the effect with the traditional pyrolysis effect from the perspective of thermal conversion behavior, products composition, and kinetics analysis. The results of the experiment showed that in the CO₂ atmosphere, the main weight loss temperature of oily sludge was mainly concentrated in the range of 300-500 °C, which is lower than the reaction temperature range of traditional pyrolysis. The yields of CO and H₂ in the products have been greatly improved, and the highest proportion in the gas products can reach 19.29% and 22.38%, respectively. The E_a (activation energy) values of oily sludge were determined to be in the range of 40-120 kJ·mol^-1 with the conversion between 0.2 and 0.8 via DAEM, KAS, Starink, and FWO methods, respectively, in which the FWO method has shown the strongest adaptability. The results of this study provide reference values for practical engineering applications.

An Efficient Deacidification Process for Safflower Seed Oil with High Nutritional Property through Optimized Ultrasonic-Assisted Technology

Safflower seed oil (SSO) is considered to be an excellent edible oil since it contains abundant essential unsaturated fatty acids and lipid concomitants. However, the traditional alkali-refined deacidification process of SSO results in a serious loss of bioactive components of the oil and also yields massive amounts of wastewater. In this study, SSO was first extracted by ultrasonic-assisted ethanol extraction (UAEE), and the extraction process was optimized using random centroid optimization. By exploring the effects of ethanol concentration, solid−liquid ratio, ultrasonic time, and the number of deacidification times, the optimum conditions for the deacidification of safflower seed oil were obtained as follows: ethanol concentration 100%, solid−liquid ratio 1:4, ultrasonic time 29 min, and number of deacidification cycles (×2). The deacidification rate was 97.13% ± 0.70%, better than alkali-refining (72.16% ± 0.13%). The values of acid, peroxide, anisidine and total oxidation of UAEE-deacidified SSO were significantly lower than those of alkali-deacidified SSO (p < 0.05). The contents of the main lipid concomitants such as tocopherols, polyphenols, and phytosterols in UAEE-decidified SSO were significantly higher than those of the latter (p < 0.05). For instance, the DPPH radical scavenging capacity of UAEE-processed SSO was significantly higher than that of alkali refining (p < 0.05). The Pearson bivariate correlation analysis before and after the deacidification process demonstrated that the three main lipid concomitants in SSO were negatively correlated with the index of peroxide, anisidine, and total oxidation values. The purpose of this study was to provide an alternative method for the deacidification of SSO that can effectively remove free fatty acids while maintaining the nutritional characteristics, physicochemical properties, and antioxidant capacity of SSO.

Chemical Composition and Thermogravimetric Behaviors of Glanded and Glandless Cottonseed Kernels

Common “glanded” (Gd) cottonseeds contain the toxic compound gossypol that restricts human consumption of the derived products. The “glandless” (Gl) cottonseeds of a new cotton variety, in contrast, show a trace gossypol content, indicating the great potential of cottonseed for agro-food applications. This work comparatively evaluated the chemical composition and thermogravimetric behaviors of the two types of cottonseed kernels. In contrast to the high gossypol content (3.75 g kg⁻¹) observed in Gd kernels, the gossypol level detected in Gl kernels was only 0.06 g kg⁻¹, meeting the FDA’s criteria as human food. While the gossypol gland dots in Gd kernels were visually observed, scanning electron microcopy was not able to distinguish the microstructural difference between ground Gd and Gl samples. Chemical analysis and Fourier transform infrared (FTIR) spectroscopy showed that Gl kernels and Gd kernels had similar chemical components and mineral contents, but the former was slightly higher in protein, starch, and phosphorus contents. Thermogravimetric (TG) processes of both kernels and their residues after hexane and ethanol extraction were based on three stages of drying, de-volatilization, and char formation. TG-FTIR analysis revealed apparent spectral differences between Gd and Gl samples, as well as between raw and extracted cottonseed kernel samples, indicating that some components in Gd kernels were more susceptible to thermal decomposition than Gl kernels. The TG and TG-FTIR observations suggested that the Gl kernels could be heat treated (e.g., frying and roasting) at an optimal temperature of 140–150 °C for food applications. On the other hand, optimal pyrolysis temperatures would be much higher (350–500 °C) for Gd cottonseed and its defatted residues for non-food bio-oil and biochar production. The findings from this research enhance the potential utilization of Gd and Gl cottonseed kernels for food applications.

Catalytic Fast Pyrolysis of Soybean Straw Biomass for Glycolaldehyde-Rich Bio-oil Production and Subsequent Extraction

In this study, soybean straw (SS) as a promising source of glycolaldehyde-rich bio-oil production and extraction was investigated. Proximate and ultimate analysis of SS was performed to examine the feasibility and suitability of SS for thermochemical conversion design. The effect of the co-catalyst (CaCl₂ + ash) on glycolaldehyde concentration (%) was examined. Thermogravimetric-Fourier-transform infrared (TG-FTIR) analysis was applied to optimize the pyrolysis temperature and biomass-to-catalyst ratio for glycolaldehyde-rich bio-oil production. By TG-FTIR analysis, the highest glycolaldehyde concentration of 8.57% was obtained at 500 °C without the catalyst, while 12.76 and 13.56% were obtained with the catalyst at 500 °C for a 1:6 ratio of SS-to-CaCl₂ and a 1:4 ratio of SS-to-ash, respectively. Meanwhile, the highest glycolaldehyde concentrations (%) determined by gas chromatography-mass spectrometry (GC-MS) analysis for bio-oils produced at 500 °C (without the catalyst), a 1:6 ratio of SS-to-CaCl₂, and a 1:4 ratio of SS-to-ash were found to be 11.3, 17.1, and 16.8%, respectively. These outcomes were fully consistent with the TG-FTIR results. Moreover, the effect of temperature on product distribution was investigated, and the highest bio-oil yield was achieved at 500 °C as 56.1%. This research work aims to develop an environment-friendly extraction technique involving aqueous-based imitation for glycolaldehyde extraction with 23.6% yield. Meanwhile, proton nuclear magnetic resonance (¹H NMR) analysis was used to confirm the purity of the extracted glycolaldehyde, which was found as 91%.

Thermogravimetric pyrolysis of onion skins: Determination of kinetic and thermodynamic parameters for devolatilization stages using the combinations of isoconversional and master plot methods

Thermogravimetric pyrolysis of onions skins was studied thoroughly for the first time. Kinetic calculations of devolatilization stages were performed applying direct Arrhenius plot (DAP) method and combinations of isoconversional and Criado's Z(α) master plot (CZMP) methods. The kinetic parameters calculated using combined methods were utilized successfully to reproduce the experimental kinetic curves whereas those calculated using DAP method failed in this sense. The average E_a values of isoconversional methods were between 164.0 and 172.0 kJ/mol. The CZMP method yielded multiple F-type reaction mechanisms. The simplified kinetic models of combined methods were also developed by using single reaction mechanisms deduced from multiple reaction mechanisms. The Friedman-CZMP combination was the best option for developing simplified/unsimplified kinetic models. Determination of reaction mechanism using DAP method by searching for the highest R² value of regression equation among several candidates was found unreliable. ΔH, ΔG and ΔS values were calculated for 10 °C/min heating rate.