Kinetics of the Catalytic Thermal Degradation of Sugarcane Residual Biomass Over Rh-Pt/CeO2-SiO2 for Syngas Production

Kinetics of In-Situ Catalytic Pyrolysis of Rice Husk Pellets Using a Multi-Component Kinetics Model

Ash-based catalysts, as low-cost materials, are applicable in biomass pyrolysis and play a role in lowering the activation energy. This study enriched the insights of different method of catalyst addition into biomass in the catalytic pyrolysis. The addition of rice husk ash as a catalyst into rice husk pellets allows for better solid-solid contact between the biomass and the catalyst, since the common methods were only solid mixing. This research aimed to investigate the thermal characteristics and kinetics of the biomass components (hemicellulose, cellulose, lignin) in the in-situ catalytic pyrolysis of rice husk pellets with the addition of husk ash. The three-independent parallel reaction kinetics model was used to calculate the kinetics parameters based on thermogravimetric analysis conducted at 303-873 K with various heating rates (5, 10, 20 K/min) and ash addition ratios (10:0, 10:1, 10:2). The thermogram shows that the pyrolysis of rice husk pellets was divided into two stages. Stage 1, ranging from 510-650 K, represented the decomposition of hemicellulose and cellulose, occurring faster with high mass loss, while Stage 2, starting at around 650 K, represented lignin decomposition, occurring more slowly with low mass loss. The catalytic activity of the ash was only apparent at high temperatures, where cellulose and lignin decomposition were more dominant. Activation energy, as a representation of catalytic activity for each component, was not always lower in catalytic pyrolysis. However, the average activation energy decreased with increasing heating rates and ash addition ratios. The addition of the catalyst slowed the decomposition of hemicellulose but accelerated the decomposition of cellulose and lignin. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Integration of steam gasification and catalytic reforming of lignocellulosic biomass as a strategy to improve syngas quality and pollutants removal

Residual biomass gasification is a promising route for the production of H₂-rich syngas. However, the simultaneous formation of pollutants such as light hydrocarbons (HCs), benzene, toluene and xylenes (BTEX), polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during gasification must be controlled. As a result, this study evaluated the effect of temperature and catalytic reforming over a Rh-Pt/CeO₂-SiO₂ catalyst during steam gasification of sugarcane residual biomass on syngas composition and pollutant removal. The above was carried out in a horizontal moving reactor, an Amberlite XAD-2 polyaromatic resin was used to collect the contaminants and characterization of the catalyst was performed. In this study, a concentration of up to 37 mol% of H₂, a yield of 23.1 g H₂ kg^-1_biomass, and a H₂/CO ratio ≥2 were achieved when gasification and reforming were integrated. In addition, the catalyst characterization showed that Rh-Pt/CeO₂-SiO₂ was not susceptible to sintering and favored the formation of hydroxyl groups that promoted CO oxidation, thereby increasing the H₂/CO ratio, as confirmed by in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). At 800 °C, where a high H₂ yield was obtained, 209 g Nm^-3 of light HCs and BTEX, 10.9 g Nm^-3 of PAHs, and 32.5 ng WHO-TEQ Nm^-3 of PCDD/Fs were formed after gasification. Interestingly, after catalytic reforming, 62% of light HCs and BTEX, 60% of PAHs, and 94% of PCDD/Fs were removed, leading to cleaner syngas with properties that allow it to be used in a wide range of energy applications.

On-Line Thermally Induced Evolved Gas Analysis: An Update-Part 1: EGA-MS

Advances in on-line thermally induced evolved gas analysis (OLTI-EGA) have been systematically reported by our group to update their applications in several different fields and to provide useful starting references. The importance of an accurate interpretation of the thermally-induced reaction mechanism which involves the formation of gaseous species is necessary to obtain the characterization of the evolved products. In this review, applications of Evolved Gas Analysis (EGA) performed by on-line coupling heating devices to mass spectrometry (EGA-MS), are reported. Reported references clearly demonstrate that the characterization of the nature of volatile products released by a substance subjected to a controlled temperature program allows us to prove a supposed reaction or composition, either under isothermal or under heating conditions. Selected 2019, 2020, and 2021 references are collected and briefly described in this review.

Catalysts for Sustainable Hydrogen Production: Preparation, Applications and Process Integration

The earth is experiencing a series of epochal emergencies, directly related to the overexploitation of natural resources [...]

Probabilistic Framework for Optimal Experimental Campaigns in the Presence of Operational Constraints

The predictive capability of any mathematical model is intertwined with the quality of experimental data collected for its calibration. Model-based design of experiments helps compute maximally informative campaigns for model...

Bioethanol Production from Sugarcane Press-Mud: Assessment of the Fermentation Conditions to Reduce Fusel Alcohol

Within a biorefinery context, bioethanol is a promising platform molecule since it can be used as raw material to produce a wide spectrum of valuable industrial products such as H2 and light olefins. However, the presence of impurities limits the conversion of bioethanol in these products. Herein, we aimed to determine the proper pretreatment and fermentation conditions to yield bioethanol with a low content of impurities, such as 3-methyl-1-butanol, by using sugarcane press-mud as feedstock. To do so, a Box-Behnken methodology was employed to select proper pretreatment and fermentation conditions. Factors assessed were temperature, stirring, and pH during fermentation of hydrolysates coming from two different pretreatment methods named as hydrothermal and acid hydrolysis. Results showed that the fermentation temperature should be kept between 26–30 °C to assure at least 91 g/L ethanol. The fusel alcohol content would be reduced by 22% at 30 °C, pH = 4.5, and 200 rpm if sugarcane press-mud is pretreated under acid hydrolysis conditions (T = 130 °C, t = 1 h, 16 g HNO3/kg solid). Further studies should aim to integrate these conditions within a biorefinery concept to yield valuable products such as H2 and ethylene.

Different pyrolysis kinetics and product distribution of municipal and livestock manure sewage sludge

Thermogravimetric analysis and pyrolyzer-gas chromatography/mass spectrometry measurements were taken to examine the kinetic behavior and product distribution on the thermal and catalytic pyrolysis of different types of sewage sludge. Compared to livestock manure sewage sludge (LMSS), municipal sewage sludge (MSS) had larger ash (30.3%) and lower fixed carbon (7.9%) contents. The peak intensities for the 1^st decomposition region (200-380 °C) on the derivative thermogravimetric curve of MSS were higher than those of LMSS. In contrast, the peak height in the 2^nd temperature region (>380 °C) of MSS was lower than that of LMSS. The activation energy for the pyrolysis of MSS (Avg. 186.5 kJ/mol) was lower than that of LMSS (Avg. 263.4 kJ/mol) over the entire conversion range. MSS produced larger amounts of fatty acids and cholesterol than LMSS. The in-situ catalytic pyrolysis of MSS over HBeta using a pyrolyzer-gas chromatography/mass spectrometry also produced larger amounts of aromatic hydrocarbons than LMSS, suggesting that its better feedstock properties strongly influence the final product oil quality.

Sugarcane Industry Waste Recovery: A Case Study Using Thermochemical Conversion Technologies to Increase Sustainability

The sugarcane industry has assumed an increasingly important role at a global level, with countries such as Brazil and India dominating the field. However, this causes environmental problems, since the industry produces large amounts of waste, such as sugarcane bagasse. This by-product, which is energetically partially recovered in sugar mills and in the pulp and paper industry, can make a significant contribution to the general use of biomass energy, if the usual disadvantages associated with products with low density and a high moisture content are overcome. From this perspective, thermochemical conversion technologies, especially torrefaction, are assumed to be capable of improving the fuel properties of this material, making it more appealing for potential export and use in far-off destinations. In this work, sugarcane samples were acquired, and the process of obtaining bagasse was simulated. Subsequently, the bagasse was dried and heat-treated at 200 and 300 °C to simulate the over-drying and torrefaction process. Afterward, product characterization was performed, including thermogravimetric analysis, elemental analysis, calorimetry, and energy densification. The results showed significant improvements in the energy content, from 18.17 to 33.36 MJ·kg−1 from dried bagasse to torrefied bagasse at 300 °C, showing that despite high mass loss, there is potential for a future value added chain for this waste form, since the increment in energy density could enhance its transportation and use in locations far off the production site.