A Comprehensive Characterization of Pyrolysis Oil from Softwood Barks

Pyrolysis of raw pine bark, pine, and Douglas-Fir bark was examined. The pyrolysis oil yields of raw pine bark, pine, and Douglas-Fir bark at 500 °C were 29.18%, 26.67%, and 26.65%, respectively. Both energy densification ratios (1.32–1.56) and energy yields (48.40–54.31%) of char are higher than pyrolysis oils (energy densification ratios: 1.13–1.19, energy yields: 30.16–34.42%). The pyrolysis oils have higher heating values (~25 MJ/kg) than bio-oils (~20 MJ/kg) from wood and agricultural residues, and the higher heating values of char (~31 MJ/kg) are comparable to that of many commercial coals. The elemental analysis indicated that the lower O/C value and higher H/C value represent a more valuable source of energy for pyrolysis oils than biomass. The nuclear magnetic resonance results demonstrated that the most abundant hydroxyl groups of pyrolysis oil are aliphatic OH groups, catechol, guaiacol, and p-hydroxy-phenyl OH groups. The aliphatic OH groups are mainly derived from the cleavage of cellulose glycosidic bonds, while the catechol, guaiacol, and p-hydroxy-phenyl OH groups are mostly attributed to the cleavage of the lignin β–O-4 bond. Significant amount of aromatic carbon (~40%) in pyrolysis oils is obtained from tannin and lignin components and the aromatic C–O bonds may be formed by a radical reaction between the aromatic and aliphatic hydroxyl groups. In this study, a comprehensive analytical method was developed to fully understand and evaluate the pyrolysis products produced from softwood barks, which could offer valuable information on the pyrolysis mechanism of biomass and promote better utilization of pyrolysis products.

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Impact of CO2 on Pyrolysis Products of Bituminous Coal and Platanus Sawdust

Polymers ◽

10.3390/polym11081370 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1370 ◽

Cited By ~ 5

Author(s):

Ying Luo ◽

Haoxi Ben ◽

Zhihong Wu ◽

Kai Nie ◽

Guangting Han ◽

...

Keyword(s):

Specific Surface ◽

Bituminous Coal ◽

Hydroxyl Groups ◽

High Porosity ◽

Pyrolysis Oil ◽

Biomass Pyrolysis ◽

Element Analysis ◽

Pyrolysis Products ◽

Pyrolysis Oils ◽

The Impact

Abundant studies have been completed about factors on the pyrolysis of coal and biomass. However, few articles laid emphasis on using CO2 as a carrier gas to explore the compositional changes of pyrolysis products in coal and biomass pyrolysis for industrial application and commercial value. The experiments on coal and biomass pyrolysis in N2 and CO2 using a horizontal tube furnace were conducted at 500 °C. The impact of introducing CO2 on the pyrolysis process of bituminous coal and Platanus sawdust was investigated. The nuclear magnetic resonance (NMR) spectra of tar and the characterizations of char including Brunner-Emmet-Teller (BET) measurements, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, and element analysis were studied. The findings in light of the experimental results show that introducing CO2 enhances the coal and biomass pyrolysis in a solid product by promoting the fracture of hydroxyl groups. It also promotes tar decomposition and the release of volatiles, which contribute to the occurrence of char with high porosity, pore volume, and specific surface. Furthermore, higher specific surface enhances the adsorption performance of char as active carbon. Simultaneously, CO2 promotes the increase of oxygen-containing aromatics especially the methoxy-containing aromatics, and the decrease of deoxygenated aromatic hydrocarbons in pyrolysis oils. In addition, the introduction of CO2 changes the amount of aliphatic compounds in various ways for the pyrolysis of coal and biomass. From a perspective of business, the changes in the composition of pyrolysis oil brought by CO2 may create new value for fuel utilization and industrial products.

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Pyrolytic Behavior of Major Biomass Components in Waste Biomass

Polymers ◽

10.3390/polym11020324 ◽

2019 ◽

Vol 11 (2) ◽

pp. 324 ◽

Cited By ~ 13

Author(s):

Haoxi Ben ◽

Zhihong Wu ◽

Guangting Han ◽

Wei Jiang ◽

Arthur Ragauskas

Keyword(s):

Chemical Shift ◽

Water Soluble ◽

Pine Bark ◽

Pyrolysis Oil ◽

Waste Biomass ◽

New Methods ◽

Biomass Components ◽

Preliminary Study ◽

Pyrolysis Oils

The pyrolytic behavior of several biomass components including cellulose, hemicellulose, lignin, and tannin, from two sources of waste biomass (i.e., pine bark and pine residues) were examined. Compared to the two aromatic-based components in the biomass, carbohydrates produced much less char but more gas. Surprisingly, tannin produced a significant amount of water-soluble products; further analysis indicated that tannin could produce a large amount of catechols. The first reported NMR chemical shift databases for tannin and hemicellulose pyrolysis oils were created to facilitate the HSQC analysis. Various C–H functional groups (>30 different C–H bonds) in the pyrolysis oils could be analyzed by employing HSQC-NMR. The results indicated that most of the aromatic C–H and aliphatic C–H bonds in the pyrolysis oils produced from pine bark and pine residues resulted from the lignin and tannin components. A preliminary study for a quantitative application of HSQC-NMR on the characterization of pyrolysis oil was also done in this study. Nevertheless, the concepts established in this work open up new methods to fully characterize the whole portion of pyrolysis oils produced from various biomass components, which can provide valuable information on the thermochemical mechanisms.

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Preparation and analysis of pyrolysis oils

Proceedings of the National Academy of Sciences of Belarus Chemical Series ◽

10.29235/1561-8331-2020-56-2-235-249 ◽

2020 ◽

Vol 56 (2) ◽

pp. 235-249

Author(s):

T. M. Henarava ◽

S. M. Leschev ◽

V. V. Sauchyn ◽

V. V. Levkina

Keyword(s):

Chemical Composition ◽

Sample Preparation ◽

Water Soluble ◽

Quantitative Composition ◽

Pyrolysis Oil ◽

Pyrolysis Products ◽

Reliable Analysis ◽

Liquid Pyrolysis Products ◽

Pyrolysis Oils ◽

Promising Source

A critical review of the methods for producing pyrolysis waste oils was carried out, the possibilities and limitations of each approach were discussed. Liquid pyrolysis products (pyrolysis oils) are promising source of valuable chemical compounds, and can be also used as a fuel. A reliable analysis of pyrolysis oils is necessary to study their component composition, basic characteristics and to select the most suitable methods for the extraction of the necessary compounds. It is known that the results of GC-MS analysis of liquid pyrolysis products are usually ambiguous: there are problems of peaks overlapping and incorrect interpretation of the data, due to the complexity of the matrix and the multicomponent composition of the object. The paper presents data on the chemical composition of pyrolysis oils obtained by elemental analysis, IR spectroscopy, NMR spectrometry, GC-MS, GC-GC/MS. Based on the presented results, pyrolysis oil usually contains aromatic compounds, water-soluble substances and hydrocarbons. It was found out that there are conflicting data on the chemical composition of the pyrolysis oils of waste tires in the scientific literature. It is proposed to carry out sequential extraction sample preparation of pyrolysis mixtures to increase the reliability and accuracy of the componential and quantitative composition of the GC-MS method. Obviously, a reliable analysis of complex pyrolysis mixtures without preliminary targeted sample preparation seems unlikely.

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Development of Highly Efficient, Glassy Carbon Foam Supported, Palladium Catalysts for Hydrogenation of Nitrobenzene

Nanomaterials ◽

10.3390/nano11051172 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1172

Author(s):

Ádám Prekob ◽

Mahitha Udayakumar ◽

Gábor Karacs ◽

Ferenc Kristály ◽

Gábor Muránszky ◽

...

Keyword(s):

Zeta Potential ◽

Glassy Carbon ◽

Palladium Nanoparticles ◽

Palladium Catalysts ◽

Sucrose Solution ◽

Supported Catalyst ◽

Carbon Foam ◽

Hydroxyl Groups ◽

Polyurethane Elastomers ◽

Oh Groups

Glassy carbon foam (GCF) catalyst supports were synthesized from waste polyurethane elastomers by impregnating them in sucrose solution followed by pyrolysis and activation (AC) using N2 and CO2 gas. The palladium nanoparticles were formed from Pd(NO3)2. The formed palladium nanoparticles are highly dispersive because the mean diameters are 8.0 ± 4.3 (Pd/GCF), 7.6 ± 4.2 (Pd/GCF-AC1) and 4.4 ± 1.6 nm (Pd/GCF-AC2). Oxidative post-treatment by CO2 of the supports resulted in the formation of hydroxyl groups on the GCF surfaces, leading to a decrease in zeta potential. The decreased zeta potential increased the wettability of the GCF supports. This, and the interactions between –OH groups and Pd ions, decreased the particle size of palladium. The catalysts were tested in the hydrogenation of nitrobenzene. The non-treated, glassy-carbon-supported catalyst (Pd/GCF) resulted in a 99.2% aniline yield at 293 K and 50 bar hydrogen pressure, but the reaction was slightly slower than other catalysts. The catalysts on the post-treated (activated) supports showed higher catalytic activity and the rate of hydrogenation was higher. The maximum attained aniline selectivities were 99.0% (Pd/GCF-AC1) at 293 K and 98.0% (Pd/GCF-AC2) at 323 K.

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Adsorption of Benzene from Aqueous Solution Using Base Modified Expanded Perlite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.622-623.1779 ◽

2012 ◽

Vol 622-623 ◽

pp. 1779-1783

Author(s):

Richard Appiah-Ntiamoah ◽

Xuan Thang Mai ◽

Francis W.Y. Momade ◽

Hern Kim

Keyword(s):

Zeta Potential ◽

Adsorption Capacity ◽

Linear Regression Analysis ◽

Basic Medium ◽

Maximum Adsorption Capacity ◽

Hydroxyl Groups ◽

Expanded Perlite ◽

Oh Groups ◽

Base Solution ◽

Ph Range

In this study, the adsorption capacity of expanded perlite (EP) for benzene at low concentrations in water was investigated after EP was treated with sodium hydroxide (NaOH). IR spectra used to characterize the modified EP showed that there was no bonding between NaOH and the hydroxyl groups on the surface of EP. However, the NaOH provided a basic medium for negatively charged surface oxide ions (-SO-) to form on EP. This fact was corroborated by pH readings of the modification solution. This reduced in pH from 10 to 9 at the end of the reaction which indicated that the hydroxyl OH- groups on the EP underwent deprotonation and hence releases H+ into the solution, and also positive sites on EP adsorbed OH- ions from the base solution. Mahir et al. in their paper Zeta potential of unexpanded and expanded perlite samples in various electrolyte media confirmed that EP has no isoelectric point and exhibits negative zeta potential in the pH range of 2-11. The surface oxides (-SO-) were believed to have given EP it adsorptive potential. Adsorption isotherm values correlated reasonably well with the Langmuir isotherm model and it parameters (qo and K) were obtained using linear regression analysis. A maximum adsorption capacity (qo) value of 19.42 mg/g was achieved.

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Proton spin–spin coupling constants and intramolecular hydrogen bonding in bromine derivatives of 1,3-dihydroxybenzene

Canadian Journal of Chemistry ◽

10.1139/v76-315 ◽

1976 ◽

Vol 54 (14) ◽

pp. 2228-2230 ◽

Cited By ~ 5

Author(s):

Ted Schaefer ◽

J. Brian Rowbotham

Keyword(s):

Hydrogen Bond ◽

Hydrogen Bonding ◽

Proton Spin ◽

Coupling Constants ◽

Spin Coupling ◽

Hydroxyl Groups ◽

Oh Groups ◽

Spin Coupling Constants ◽

Spin Spin Coupling ◽

Derivatives Of

The conformational preferences in CCl4 solution at 32 °C of the hydroxyl groups in bromine derivatives of 1,3-dihydroxybenzene are deduced from the long-range spin–spin coupling constants between hydroxyl protons and ring protons over five bonds. Two hydroxyl groups hydrogen bond to the same bromine substituent in 2-bromo-1,3-dihydroxybenzene but prefer to hydrogen bond to different bromine substituents when available, as in 2,4-dibromo-1,3-dihydroxybenzene. When the OH groups can each choose between two ortho bromine atoms, as in 2,4,6-tribromoresorcinol, they apparently do so in a very nearly statistical manner except that they avoid hydrogen bonding to the common bromine atom.

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The Role of Carboxyl and Hydroxyl Groups of Humic Acid in Removing AuCl4- from Aqueous Solution

Indonesian Journal of Chemistry ◽

10.22146/ijc.23620 ◽

2017 ◽

Vol 17 (1) ◽

pp. 95 ◽

Cited By ~ 5

Author(s):

Sri Sudiono ◽

Mustika Yuniarti ◽

Dwi Siswanta ◽

Eko Sri Kunarti ◽

Triyono Triyono ◽

...

Keyword(s):

Aqueous Solution ◽

Humic Acid ◽

Peat Soil ◽

Sharp Decrease ◽

Hydroxyl Groups ◽

Mixed Solution ◽

Oh Groups ◽

Characterization Result ◽

Ft Ir

Humic acid (HA) extracted from peat soil according to the recommended procedure of the International Humic Substances Society (IHSS) has been tested to remove AuCl4- from aqueous solution. The removal was optimum at pH 2.0 and it was mainly dictated by attachment through hydrogen bonding to unionized carboxyl (–COOH) groups and reduction by the action of the hydroxyl (–OH) groups to gold (Au) metal. The removal of AuCl4- improved after HA was purified through repeated immersion and shaking in a mixed solution containing 0.1 M HCl and 0.3 M HF. When the purification led to the sharp decrease in ash content from 39.34 to 0.85% (w/w) and significant increase in both the –COOH and –OH contents from 3240 to 3487 mmol/kg and from 4260 to 4620 mmol/kg, respectively; the removal of AuCl4- improved from 0.105 to 0.133 mmol/g. This improvement of AuCl4- removal by the purified HA was accompanied by higher ability in reduction to Au metal. The attached AuCl4- on –COOH groups of both crude and purified HAs was qualitatively observed by the characterization result of FT-IR spectroscopy, while the presence of Au metal on the surface of those HAs was verified by the characterization result of XRD.

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Cell adhesion to hydroxyl groups of a monolayer film

Journal of Cell Science ◽

10.1242/jcs.91.2.269 ◽

1988 ◽

Vol 91 (2) ◽

pp. 269-279

Author(s):

N.F. Owens ◽

D. Gingell ◽

A. Trommler

Keyword(s):

Cell Adhesion ◽

Flow Chamber ◽

Cell Contact ◽

Hydroxyl Groups ◽

Adjacent Area ◽

Oh Groups ◽

Monomolecular Films ◽

Langmuir Blodgett Films ◽

Long Chain Alcohol ◽

Minimal Measure

We have studied cells on chemically defined monomolecular films of the long-chain alcohol docosanol. Langmuir-Blodgett films of the alcohol were deposited on glass coverslips, previously made hydrophobic with octadecyl groups. This gives films in which the alcohol headgroups face outwards to the water. Molecular orientation and film integrity were shown by a fluorescence adsorption test. Cell contacts on the films were observed in media without proteins by interference reflection microscopy (IRM) and the mechanics of detachment were examined by hydrodynamic shearing in a flow chamber. Cell contact with docosanol was compared with that on an adjacent area of octadecyl glass without a monolayer. Dictyostelium amoebae settled and spread on both docosanol and octadecyl glass, but little or no locomotion was seen on docosanol. On octadecyl glass the amoebae moved actively, forming ultrathin cytoplasmic lamellae, which look dark under IRM, and left distinctive trails of membranous debris. Hydrodynamic shearing showed that the amoebae stuck strongly to both surfaces and could not be removed from either at the maximum attainable wall shear stress of 6Nm-2. Red blood cells also adhered to both surfaces and removal from both occurred between 1 and 3Nm-2. IRM and scanning electron microscopy (SEM) studies indicated that this force leads to a minimal measure of red cell adhesion, since removal often involved the breakage of cytoplasmic tethers. Our results show that alcoholic -OH groups, in a two-dimensional array, provide a surface that is strongly adhesive for cells. No other method has made it possible to demonstrate cell adhesion purely to -OH groups, in a known orientation and density, and in the absence of any other functional groups on the interface.

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Hydroxyl-Group Identification Using O K-Edge XAFS in Porous Glass Fabricated by Hydrothermal Reaction and Low-Temperature Foaming

Molecules ◽

10.3390/molecules24193488 ◽

2019 ◽

Vol 24 (19) ◽

pp. 3488 ◽

Cited By ~ 2

Author(s):

Masanori Suzuki ◽

Shigehiro Maruyama ◽

Norimasa Umesaki ◽

Toshihiro Tanaka

Keyword(s):

Low Temperature ◽

Surface Area ◽

Porous Glass ◽

Hydrothermal Reaction ◽

Group Identification ◽

Fluorescence Yield ◽

Hydroxyl Group ◽

Hydroxyl Groups ◽

Oh Groups ◽

Xafs Spectroscopy

Porous glass was prepared by the hydrothermal reaction of sodium borosilicate glass, and oxygen-ion characterization was used to identify the hydroxyl groups in its surface area. A substantial amount of “water” was introduced into the ionic structure as either OH− groups or H2O molecules through the hydrothermal reaction. When the hydrothermally treated glass was reheated at normal pressures, a porous structure was formed due to the low-temperature foaming resulting from the evaporation of H2O molecules and softening of the glass. Although it was expected that the OH− groups would remain in the porous glass, their distribution required clarification. Oxygen K-edge X-ray absorption fine structure (XAFS) spectroscopy enables the bonding states of oxygen ions in the surface area and interior to be characterized using the electron yield (EY) and fluorescence yield (FY) mode, respectively. The presence of OH− groups was detected in the O K-edge XAFS spectrum of the porous glass prepared by hydrothermal reaction with a corresponding pre-edge peak energy of 533.1 eV. In addition, comparison of the XAFS spectra obtained in the EY and FY modes revealed that the OH− groups were mainly distributed in the surface area (depths of several tens of nanometers).

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