Catalytic pyrolysis is an effective means for high-value utilization of biomass. This study investigated the effect of solid base catalysts (CaO, calcium aluminate catalysts CaAl-1, CaAl-2, CaAl-3), acid zeolite catalysts (ZSM-5, Fe/ZSM-5, Co/ZSM-5, Ni/ZSM-5, Cu/ZSM-5, Zn/ZSM-5) and base-acid tandem catalysts on pine sawdust pyrolysis using Py-GC/MS. Acid zeolite catalysts exhibited robust deoxidation and aromatization capabilities, favoring aromatics, while solid base catalysts yielded more phenols and ketones.
View Article and Find Full Text PDFThere is a lack of detailed research on the production of isoprene and D-limonene by solid base-catalysed thermal depolymerization of waste tires (WTs). This work aimed to investigate the thermal decomposition characteristics, reaction kinetics, high value-added products production and potential mechanisms during WT pyrolysis in the presence of calcium oxide (CaO) via Thermogravimetry-Fourier Transform Infrared spectrometer (TG-FTIR) and Pyrolyzer-Gas Chromatography/Mass spectrometry (Py-GC/MS). The results obtained from TG indicated that CaO accelerated depolymerization in terms of reducing the reaction temperature, which is also reflected in the kinetic parameters.
View Article and Find Full Text PDFThe pyrolysis characteristics of land biomass (corn stalks (Cs), pine sawdust (Ps)) and coastal zone biomass (Jerusalem artichoke stalks (JAs) and reed (Re)) were investigated based on thermogravimetric analysis (TGA) and products' analysis. The kinetic parameters were obtained by three isoconversional methods (Friedman, KAS, and FWO) and one model-fitting method (DAEM). The simultaneous effect of high temperature (700-900 °C) and high heating rate (1000 °C/s) on the pyrolysis product simulating the typical conditions of a fluidized bed gasifier was studied.
View Article and Find Full Text PDFTo understand the fast pyrolysis kinetics and product evolution of waste pine sawdust, high heating rate thermogravimetry-Fourier transform infrared (TG-FTIR) was used to obtain the kinetic parameters and the chemical groups formed during the pyrolysis process, while pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to investigate the detailed compositions of products under the staged (seven stages from 300 to 600 °C) and direct fast pyrolysis process. Spectral bands were identified for acids, alcohols, aldehydes, aromatics, esters, ethers, hydrocarbons, ketones, phenols, and sugars. Research found that the apparent activation energy for fast pyrolysis is much higher than that of slow pyrolysis.
View Article and Find Full Text PDFFurfural residue (FR) is an inevitable by-product of industrial furfural production. If FR is not managed properly, it will result in environmental problems. In this study, FR was used as a novel precursor for activated carbon (AC) production by HPO activation under different conditions.
View Article and Find Full Text PDFFast partial hydropyrolysis of biomass was carried out at the level with hydrogen concentration of 0% to 30% and temperatures ranging from 700 to 900 °C by using a downer pyrolyzer. A theoretical parametric effect on yields and properties of the hydropyrolysis products were clarified. It was found that the volatile matter evolved during pyrolysis was substantially increased in the presence of hydrogen.
View Article and Find Full Text PDFAn environmentally friendly lignin-based composite (Lignin-PEI) was facilely prepared via cross-linking enzymatic hydrolysis lignin matrix and branched poly (ethylene imine). The specific physicochemical and structural properties of lignin-PEI were characterized by elemental analysis, N physisorption, GPC, TG, SEM, FT-IR and XPS. The nitrogen content of lignin-PEI was 9.
View Article and Find Full Text PDFA novel natural deep eutectic solvent (NDES) with water content ranging from 65 to 93 wt%, in which betaine (Bet) acts as the cation and amino acids (AAs) as the anions, was prepared by a simple and green chemical route. [Bet][AA] NDES showed excellent xylan and lignin solubility, however, scare cellulose solubility. A mild and facile pretreatment process with [Bet][AA] NDES was carried out at 60 °C for 5 h.
View Article and Find Full Text PDFThe catalytic activity of biochar for tar removal was evaluated in a bench-scale combined fixed bed reactor by comparison of gaseous tar catalytic cracking behaviors over land (Corn stalks, Cs), coastal (Reed, Re) and marine (Sargassum horneri, Sh) char catalyst. The experiments demonstrated that the tar yield after addition of the biochar was reduced significantly; the tar conversion efficiency reached to 94.6% for catalytic at 850 °C with 50 mm char bed length using Re char.
View Article and Find Full Text PDFSelectively breaking the C-O bonds within biomass during catalytic fast pyrolysis (CFP) is desired, but extremely challenging. Herein, we develop a series of metal-oxide nanocomposites composed of W, Mo, Zr, Ti, or Al. It is demonstrated that the nanocomposites of WO-TiO-AlO exhibit the highest deoxygenation ability during CFP of lignin, which can compete with the commercial HZSM-5 catalyst.
View Article and Find Full Text PDFA lignin-based biosorbent (LSMA) was prepared by cross-linking lignosulfonate and N-methylaniline with the aid of ammonium persulfate for efficient removal of Cr(VI) from aqueous solution. Since LSMA possessed both amino groups and oxygen-containing functional groups, such as phenolic, carboxyl, and sulfonic groups, the maximum adsorption capacity of 1264.8 mg/g was achieved at 318 K according to the Langmuir isotherm.
View Article and Find Full Text PDFThe steam gasification properties and kinetics, products distribution and syngas composition derived from land, coastal zone and marine biomass have been studied by TGA and free-fall tubular gasifier. Volume model, shrinking core model and random pore model were applied to describe the reaction kinetics. The influence of temperature and fuel types on steam gasification in a free-fall tubular gasifier were clarified simultaneously.
View Article and Find Full Text PDFThis study aimed at investigating fast pyrolysis behavior and products distribution of two typical coastal zone biomass fuels (Jerusalem artichoke stalk (JAS) and reeds (Re) by TGA and a homemade down tube reactor. The kinetic analysis with different ramping rates was conducted by FWO and DAEM models. The liquid, gaseous and solid products are characterized to study the influence of temperature.
View Article and Find Full Text PDFThe aim of this work was to study the pyrolysis behavior of castor oil, corn starch, soy protein, lignin, xylan, and cellulose. The pyrolysis behavior, gaseous product evolution, kinetics and thermodynamics of these model compounds were investigated via TG-FTIR under high heating rates. The TG/DTG curves showed that castor oil had the widest pyrolysis temperature zone and lignin had the highest residual rate.
View Article and Find Full Text PDFMunicipal solid waste treatment has been and will continue to be a major issue facing countries worldwide, and gasification has recently gained more attention as an efficient and clean technology. The steam gasification characteristics and kinetics of five different municipal solid waste chars had been investigated by the method of isothermal thermogravimetric analysis. The results showed that the gasification reactivity increased with gasification temperature.
View Article and Find Full Text PDFEvid Based Complement Alternat Med
November 2011
The pyrolytic kinetics of Phragmites australis was investigated using thermogravimetric analysis (TGA) method with linear temperature programming process under an inert atmosphere. Kinetic expressions for the degradation rate in devolatilization and combustion steps have been obtained for P. australis with Dollimore method.
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