scholarly journals Catalytic Pyrolysis of Lignin Model Compounds (Pyrocatechol, Guaiacol, Vanillic and Ferulic Acids) over Nanoceria Catalyst for Biomass Conversion

2021 ◽  
Vol 11 (16) ◽  
pp. 7205
Author(s):  
Nataliia Nastasiienko ◽  
Tetiana Kulik ◽  
Borys Palianytsia ◽  
Julia Laskin ◽  
Tetiana Cherniavska ◽  
...  
Keyword(s):  
Catalytic Pyrolysis ◽  
Biomass Conversion ◽  
Value Added ◽  
Spectroscopic Studies ◽  
Surface Complexes ◽  
General Transformation ◽  
Carboxylate Groups ◽  
Transformation Mechanisms ◽  
Ft Ir ◽  
Temperature Programmed

Understanding the mechanisms of thermal transformations of model lignin compounds (MLC) over nanoscale catalysts is important for improving the technologic processes occurring in the pyrolytic conversion of lignocellulose biomass into biofuels and value-added chemicals. Herein, we investigate catalytic pyrolysis of MLC (pyrocatechol (P), guaiacol (G), ferulic (FA), and vanillic acids (VA)) over nanoceria using FT-IR spectroscopy, temperature-programmed desorption mass spectrometry (TPD MS), and thermogravimetric analysis (DTG/DTA/TG). FT-IR spectroscopic studies indicate that the active groups of aromatic rings of P, G, VA, and FA as well as carboxylate groups of VA and FA are involved in the interaction with nanoceria surface. We explore the general transformation mechanisms of different surface complexes and identify their decomposition products. We demonstrate that decomposition of carboxylate acid complexes occurs by decarboxylation. When FA is used as a precursor, this reaction generates 4-vinylguaiacol. Complexes of VA and FA formed through both active groups of the aromatic ring and decompose on the CeO2 surface to generate hydroxybenzene. The formation of alkylated products accompanies catalytic pyrolysis of acids due to processes of transalkylation on the surface.

scholarly journals Catalytic Pyrolysis of Lignin Model Compound (Ferulic Acid) over Alumina: Surface Complexes, Kinetics, and Mechanisms

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1508
Author(s):  
Tetiana Kulik ◽  
Nataliia Nastasiienko ◽  
Borys Palianytsia ◽  
Mykola Ilchenko ◽  
Mats Larsson
Keyword(s):  
Ferulic Acid ◽  
Catalytic Pyrolysis ◽  
Model Compound ◽  
Alumina Surface ◽  
Surface Complexes ◽  
Lignin Model Compound ◽  
Renewable Biomass ◽  
Benzene Toluene ◽  
Ft Ir ◽  
Temperature Programmed

Studies of the thermochemical properties of the important model compound of lignin-ferulic acid (FA) and its surface complexes are substantial for developing technologies for catalytic pyrolysis of renewable biomass into biofuels and lignin-derived chemicals as well as for bio-oil upgrading. In this work, the catalytic pyrolysis of ferulic acid over alumina was studied by temperature-programmed desorption mass spectrometry (TPD MS), in situ FT-IR spectroscopy, thermogravimetric analysis, and DFT calculations. We established that both the carboxyl group and the active groups (HO and CH3O) of the aromatic ring interact with the alumina surface. We calculated the kinetic parameters of formation of the main products of catalytic pyrolysis: 4-vinylguaiacol, guaiacol, hydroxybenzene, benzene, toluene, cresol, naphthalene, and PACs. Possible methods of their forming from the related surface complexes of FA are suggested.

scholarly journals Thermal Transformation of Caffeic Acid on the Nanoceria Surface Studied by Temperature Programmed Desorption Mass-Spectrometry, Thermogravimetric Analysis and FT–IR Spectroscopy

2019 ◽  
Vol 3 (1) ◽  
pp. 34 ◽  
Author(s):  
Nataliia Nastasiienko ◽  
Borys Palianytsia ◽  
Mykola Kartel ◽  
Mats Larsson ◽  
Tetiana Kulik
Keyword(s):  
Mass Spectrometry ◽  
Thermogravimetric Analysis ◽  
Cerium Dioxide ◽  
Temperature Programmed Desorption ◽  
Hydroxyl Groups ◽  
Surface Complexes ◽  
Desorption Mass Spectrometry ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Ft Ir Spectroscopy

The studies of pyrolysis of caffeic acid (CA) and its surface complexes is important for the development of technologies of heterogeneous catalytic pyrolysis of plant- and wood- based renewable biomass components. In this work, the structure and thermal transformations of the surface complexes of CA on the surface of nanoceria were investigated using Fourier transform–infrared (FT–IR) spectroscopy, thermogravimetric analysis (TGA) and temperature-programmed desorption mass spectrometry (TPD MS). It was found that CA on the surface of cerium dioxide forms several types of complexes: bidentate carboxylates, monodentate carboxylates and complexes formed as a result of interaction with phenolic hydroxyl groups. This is due to the ability of nanosized cerium dioxide to generate basic hydroxyl groups that can deprotonate phenolic groups to form phenolates on the surface. The main pyrolysis products were identified. The possible ways of forming 3,4-dihydroxyphenylethylene, acetylene carboxylic acid, pyrocatechol and phenol from surface complexes of CA were suggested. It was established that on the nanoceria surface effectively occur the decarboxylation, decarbonylation, and dehydration reactions of the CA, which are the desirable processes in biomass conversion technologies.

scholarly journals Hierarchical Porous MIL-101(Cr) Solid Acid-Catalyzed Production of Value-Added Acetals from Biomass-Derived Furfural

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3498
Author(s):  
Shengqi Liu ◽  
Ye Meng ◽  
Hu Li ◽  
Song Yang
Keyword(s):  
Biomass Conversion ◽  
Value Added ◽  
Chlorosulfonic Acid ◽  
Hierarchical Porous ◽  
Acidic Sites ◽  
Metal Organic ◽  
Ft Ir ◽  
Good Catalytic Activity ◽  
Valuable Compounds ◽  
Adsorption Desorption

Considering economic and environmental impacts, catalytic biomass conversion to valuable compounds has attracted more and more attention. Of particular interest is furfural, a versatile biorefinery platform molecule used as a feedstock for the production of fuels and fine chemicals. In this study, the Cr-based metal-organic frameworks (MOFs) MIL-101 were modified by chlorosulfonic acid, and MIL-101 was changed into a hierarchical MOF structure with smaller particles and lower particle crystallinity by CTAB, which significantly improved the acidic sites of the MOFs. The original and modified MIL-101(Cr) catalysts were characterized by XRD, N2 adsorption-desorption, SEM, TEM, and FT-IR. The effects of different catalysts, reaction temperature, catalyst amount, and alcohol type on the reaction were studied. Under the action of the MOFs catalyst, a new mild route for the condensation of furfural with various alkyl alcohols to the biofuel molecules (acetals) was proposed. The conversion route includes the conversion of furfural up to 91% yield of acetal could be obtained within 1 h solvent-free and in room-temperature reaction conditions. The sulfonic acid-functionalized MIL-101(Cr) is easy to recover and reuse, and can still maintain good catalytic activity after ten runs.

scholarly journals Catalytic pyrolysis of lignin-cellulose biomass and its model phenolic components on the nanosized oxides surface

2021 ◽  
pp. 241-254
Author(s):  
Tetiana V. Kulik ◽  
◽  
Nataliia S. Nastasiienko ◽  
Borys B. Palianytsia ◽  
Kostiantyn S. Kylik ◽  
...  
Keyword(s):  
Catalytic Pyrolysis ◽  
Raw Materials ◽  
Rapeseed Meal ◽  
Spectroscopic Studies ◽  
Raw Material ◽  
Thermal Transformations ◽  
Renewable Biomass ◽  
Fundamental Research ◽  
Nanosized Oxides ◽  
Temperature Programmed

Lignocellulose is currently considered as a potential renewable source of a wide range of valuable chemicals, including aromatics. Catalytic pyrolysis is the promising method for the conversion of biomass raw materials. The development of renewable biomass pyrolysis technologies requires fundamental research on catalytic thermal transformations of lignocellulosic raw materials. Therefore, in this work, the methods of IR spectroscopy, temperature programmed desorption mass spectrometry (TPD MS) and thermogravimetric analysis were used to investigate the catalytic thermal transformations of rapeseed meal (RM) and ferulic acid (FA) as a model phenol-containing component of such raw material on the surface of nanosized oxides CeO2, SiO2 TiO2/SiO2, Al2O3/SiO2 and CeO2/SiO2. The most effective catalyst in the conversion of biomass to ketones was a nanocomposite CeO2/SiO2 with the highest content of nanoparticles of CeO2 (24%). According to the data of FTIR spectroscopic studies, the interaction of FA with the CeO2 surface occurs with the participation of phenol and carboxyl groups. The main products of thermal decomposition of FA on the surface of CeO2 are 3-methoxy-4-vinylphenol, guaiacol, coumaric acid and hydroxybenzene. Condensed aromatics (naphthalene, alkylnaphthalenes) were registered in small quantities.

scholarly journals Catalytic Pyrolysis of Aliphatic Carboxylic Acids into Symmetric Ketones over Ceria-Based Catalysts: Kinetics, Isotope Effect and Mechanism

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 179 ◽  
Author(s):  
Tetiana Kulik ◽  
Borys Palianytsia ◽  
Mats Larsson
Keyword(s):  
Carboxylic Acids ◽  
Isotope Effect ◽  
Catalytic Pyrolysis ◽  
Value Added ◽  
Linear Free Energy ◽  
Kinetic Isotope ◽  
Energy Relationships ◽  
Temperature Programmed ◽  
Aliphatic Carboxylic Acids ◽  
Pyrolysis Of Biomass

Ketonization is a promising way for upgrading bio-derived carboxylic acids from pyrolysis bio-oils, waste oils, and fats to produce high value-added chemicals and biofuels. Therefore, an understanding of its mechanism can help to carry out the catalytic pyrolysis of biomass more efficiently. Here we show that temperature-programmed desorption mass spectrometry (TPD-MS) together with linear free energy relationships (LFERs) can be used to identify catalytic pyrolysis mechanisms. We report the kinetics of the catalytic pyrolysis of deuterated acetic acid and a reaction series of linear and branched fatty acids into symmetric ketones on the surfaces of ceria-based oxides. A structure–reactivity correlation between Taft’s steric substituent constants Es* and activation energies of ketonization indicates that this reaction is the sterically controlled reaction. Surface D3-n-acetates transform into deuterated acetone isotopomers with different yield, rate, E≠, and deuterium kinetic isotope effect (DKIE). The obtained values of inverse DKIE together with the structure–reactivity correlation support a concerted mechanism over ceria-based catalysts. These results demonstrate that analysis of Taft’s correlations and using simple equation for estimation of DKIE from TPD-MS data are promising approaches for the study of catalytic pyrolysis mechanisms on a semi-quantitative level.

Production of Value-Added Aromatics from Wasted COVID-19 Mask via Catalytic Pyrolysis

2021 ◽  
pp. 117060
Author(s):  
Seul Bee Lee ◽  
Jechan Lee ◽  
Yiu Fai Tsang ◽  
Young-Min Kim ◽  
Jungho Jae ◽  
...  
Keyword(s):  
Catalytic Pyrolysis ◽  
Value Added

scholarly journals Extraction of sugarcane bagasse arabinoxylan, integrated with enzymatic production of xylo-oligosaccharides and separation of cellulose

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Leila Khaleghipour ◽  
Javier A. Linares-Pastén ◽  
Hamid Rashedi ◽  
Seyed Omid Ranaei Siadat ◽  
Andrius Jasilionis ◽  
...  
Keyword(s):  
Sugarcane Bagasse ◽  
Sugar Content ◽  
Value Added ◽  
Apparent Molecular Weight ◽  
Bacillus Halodurans ◽  
Glycoside Hydrolase Family ◽  
High Concentration ◽  
Enzymatic Production ◽  
Successful Separation ◽  
Ft Ir

AbstractSugarcane processing roughly generates 54 million tonnes sugarcane bagasse (SCB)/year, making SCB an important material for upgrading to value-added molecules. In this study, an integrated scheme was developed for separating xylan, lignin and cellulose, followed by production of xylo-oligosaccharides (XOS) from SCB. Xylan extraction conditions were screened in: (1) single extractions in NaOH (0.25, 0.5, or 1 M), 121 °C (1 bar), 30 and 60 min; (2) 3 × repeated extraction cycles in NaOH (1 or 2 M), 121 °C (1 bar), 30 and 60 min or (3) pressurized liquid extractions (PLE), 100 bar, at low alkalinity (0–0.1 M NaOH) in the time and temperature range 10–30 min and 50–150 °C. Higher concentration of alkali (2 M NaOH) increased the xylan yield and resulted in higher apparent molecular weight of the xylan polymer (212 kDa using 1 and 2 M NaOH, vs 47 kDa using 0.5 M NaOH), but decreased the substituent sugar content. Repeated extraction at 2 M NaOH, 121 °C, 60 min solubilized both xylan (85.6% of the SCB xylan), and lignin (84.1% of the lignin), and left cellulose of high purity (95.8%) in the residuals. Solubilized xylan was separated from lignin by precipitation, and a polymer with β-1,4-linked xylose backbone substituted by arabinose and glucuronic acids was confirmed by FT-IR and monosaccharide analysis. XOS yield in subsequent hydrolysis by endo-xylanases (from glycoside hydrolase family 10 or 11) was dependent on extraction conditions, and was highest using xylan extracted by 0.5 M NaOH, (42.3%, using Xyn10A from Bacillus halodurans), with xylobiose and xylotriose as main products. The present study shows successful separation of SCB xylan, lignin, and cellulose. High concentration of alkali, resulted in xylan with lower degree of substitution (especially reduced arabinosylation), while high pressure (using PLE), released more lignin than xylan. Enzymatic hydrolysis was more efficient using xylan extracted at lower alkaline strength and less efficient using xylan obtained by PLE and 2 M NaOH, which may be a consequence of polymer aggregation, via remaining lignin interactions.

scholarly journals Gallium nitride catalyzed the direct hydrogenation of carbon dioxide to dimethyl ether as primary product

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chang Liu ◽  
Jincan Kang ◽  
Zheng-Qing Huang ◽  
Yong-Hong Song ◽  
Yong-Shan Xiao ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Dimethyl Ether ◽  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Density Functional Theory Calculations ◽  
Product Distribution ◽  
Spectroscopic Studies ◽  
Direct Hydrogenation ◽  
Hydrogenation Of Co

AbstractThe selective hydrogenation of CO2 to value-added chemicals is attractive but still challenged by the high-performance catalyst. In this work, we report that gallium nitride (GaN) catalyzes the direct hydrogenation of CO2 to dimethyl ether (DME) with a CO-free selectivity of about 80%. The activity of GaN for the hydrogenation of CO2 is much higher than that for the hydrogenation of CO although the product distribution is very similar. The steady-state and transient experimental results, spectroscopic studies, and density functional theory calculations rigorously reveal that DME is produced as the primary product via the methyl and formate intermediates, which are formed over different planes of GaN with similar activation energies. This essentially differs from the traditional DME synthesis via the methanol intermediate over a hybrid catalyst. The present work offers a different catalyst capable of the direct hydrogenation of CO2 to DME and thus enriches the chemistry for CO2 transformations.

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

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