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Adhesive bond performance of heat-treated wood at various conditions
(Triveni Enterprises, 2016) Kol, Hamiyet Sahin; Ozbay, Gunay
Heat treatment of wood leads to chemical, structural and physical changes in wood constituents, which can significantly affect the bonding performance of wood in several ways depending on the adhesive type used. In the present study, fir (Abies bornrniineriana Mattf.) and beech (Fagus orientalis L.) were heat treated at 170 degrees C, 180 degrees C, 190 degrees C, 200 and 212 degrees C for 2 hours. Four different types of adhesives were used for bonding process: melamine-urea-formaldehyde (MUF), melamine formaldehyde (MF), phenol formaldehyde (PF), and polyurethane (PUR) For all the pretreatment conditions, highest shear strength of adhesive bonds of each adhesive system was observed for untreated samples and shear strength decreased with increasing heat treatment. The strength of each adhesive bond of samples which were soaked in water was much less than dry samples, approximately half of the dry strength. Generally, the shear strength of the adhesive bonds after boiling was smaller than or similar to the values obtained for soaking. The untreated samples lost more strength after soaking and boiling than heat treated samples. With increasing heat treatment severity, reduction in shear strength increased in dry samples while decreased in soaking and boiling samples. For instance, after soaking, the untreated samples lost more strength (almost 39%) than heat treated samples (almost 24% for most severely heat treated samples). The results showed that the shear strength of adhesive bonds was influenced by heat treatment and depended on pretreatment of samples prior to testing. In general, all adhesives used performed in quite a similar way for all pretreatment conditions, and the bonding performance of heat treated fir wood was less satisfactory than that of beech wood for all adhesive system and condition.
Adhesive characteristics and bonding performance of phenol formaldehyde modified with phenol-rich fraction of crude bio-oil
(Taylor & Francis Ltd, 2015) Aslan, Metin; Ozbay, Gunay; Ayrilmis, Nadir
Commercial phenol-formaldehyde (PF) adhesive was gradually substituted by increasing amount of the phenol-rich fraction (PRF) of crude bio-oil up to 40wt%. The effect of substitution level of the PRF on the chemical, curing, morphological scanning electronic microscope(SEM), and bonding characteristics of the PF adhesive was determined. The tensile-shear strength of single lap-joint wood specimens bonded with the modified PF adhesives was investigated under indoor and outdoor exposure conditions. The chemical composition of the PRF was investigated using some chromatographic and spectroscopic techniques. Further structural analysis of PRF-modified PF adhesives was determined using Fourier transform infrared spectroscopy(FTIR). The PRF resol had a similar molecular structure to commercial pure phenol resol adhesive. The PRF could be partially substitute for the petroleum-based phenol in commercial PF adhesives with inexpensive phenols derived from lignocellulosic wastes.
BIO-OIL PRODUCTION FROM CATALYTIC PYROLYSIS METHOD OF FURNITURE INDUSTRY SAWDUST
(Gazi Univ, Fac Engineering Architecture, 2013) Ozcifci, Ayhan; Ozbay, Gunay
In this study, scots pine (Pinus sylvestris L.) sawdust was used as biomass resources. Catalyzed and uncatalyzed (thermal) pyrolysis processes were conducted in a fixed-bed reactor. The effects of the parameters on pyrolysis product yields such as temperature and catalysis type were investigated. The pyrolysis of the experimental samples that have a particle size in the range of 0.850-1.60 mm were carried out at the temperatures of 400, 500 and 600 degrees C at the heating rate of 5 degrees C/min. Nitrogen gas (N-2) flow was used at the rate of 30 ml/min during the process. Basic salts such as Na2CO3, K2CO3 and Lewis acid (FeCl3) were used as catalyses. As a result, it was determined that temperature and catalysis types were effective parameters in the yields of char, bio-oil and gas products. Also it was determined that the conversion of wood materials into fuel or valuable chemicals with the pyrolysis method is an applicable technology.
Bonding performance of wood bonded with adhesive mixtures composed of phenol-formaldehyde and bio-oil
(Elsevier Science Bv, 2015) Ozbay, Gunay; Ayrilmis, Nadir
This study investigated the bonding performance of phenol-formaldehyde (PF) adhesive containing different amounts of pyrolysis bio-oil. The amount of bio-oil in the PF adhesive was gradually increased to 40 wt%. Pine wood sawdust was converted into renewable chemical feedstock for the production of bio-based phenolic adhesive. The chemical composition of the bio-oil, and the viscosity and pH of each type of adhesive mixtures were analyzed. The bonding performance of the adhesive mixtures was determined using single lap-joint tensile specimens. The results showed the bond quality of the PF adhesive containing 20 wt%, bio-oil was better than that of the commercial PF adhesive under dry conditions. The PF adhesive containing 20 wt% the bio-oil met the requirements for durability classes of 1-3 specified in EN 12765, (2002). Environmentally friendly adhesives from biomass can be used as a substitute for existing petroleum based PF adhesive in the manufacture of wood-based panels. (C) 2014 Elsevier B.V. All rights reserved.
Catalytic Pyrolysis of Pine Wood Sawdust to Produce Bio-oil: Effect of Temperature and Catalyst Additives
(Taylor & Francis Inc, 2015) Ozbay, Gunay
In this work, non-catalytic pyrolysis of Turkish pine (Pinus brutia Ten.) wood sawdust was performed in a fixed-bed reactor at various temperatures to obtain the optimum conditions to achieve a maximum bio-oil yield. The highest yield of bio-oil was obtained about 46 wt% at 550 degrees C for non-catalytic pyrolysis. At the optimum conditions, the effects of different catalyst types (KOH, ZnCl2, and ZnO) and amount of catalyst (5, 10, 15, and 20wt%) on the pyrolysis product yields and bio-oil properties were investigated. The presence of catalysts changed the product distribution considerably. Increasing the amount of catalyst led to a decrease in the yield of liquid product, while the gas and char yields increased compared to non-catalytic pyrolysis. The chemical compositions of bio-oil were determined with GC-MS analyses. It was determined that bio-oils contain a large variety of organic compounds, such as furans, aldehydes, ketones, phenols, acids, benzenes, alcohols, alkanes, and polycyclic aromatic hydrocarbons (PAHs). The catalysis by KOH significantly increased the levels of phenols, while it reduced the formation of acids and aldehydes. ZnCl2 produced bio-oil with high percentages of aldehydes. Moreover, ZnO reduced the proportion of PAH in the bio-oil. These results demonstrated that bio-oils could improve with a catalyst. Therefore, catalyst selection for high bio-oil quality is crucial in industrial applications.
Catalytic pyrolysis of waste melamine coated chipboard
(Wiley-Blackwell, 2013) Ozbay, Gunay; Ozcifci, Ayhan; Karagoz, Selhan
Catalytic pyrolysis of waste melamine coated chipboard was performed in a fixed-bed reactor at 400 degrees C, 500 degrees C, 600 degrees C, and 700 degrees C and a residence time of 1 h. The effects of temperature and catalysts on both product distribution and bio-oil composition were discussed. Lewis acids (AlCl3, TiCl4, and FeCl3), bases (NaOH and KOH), and basic salts (Na2CO3 and K2CO3) were used as catalysts in the pyrolysis process. The product distributions were changed depending on both the type of catalyst and temperature. Bio-oil obtained from the pyrolysis of melamine coated chipboard contained a large variety of oxygenated hydrocarbons. Phenols were found to be the major compounds identified in bio-oils for all tested runs. The bio-oils produced by Lewis acids contained aldehydes. However, the bio-oils obtained from the thermal run, the run with bases, and the run with basic salts did not contain these compounds. (c) 2011 American Institute of Chemical Engineers Environ Prog, 32: 156161, 2013.
Chemical Characterization of Bio-oil from Pyrolysis of Undecayed and Decayed Fagus orientalis Wood
(Zagreb Univ, Fac Forestry, 2017) Hosseinihashemi, Seyyed Khalil; Hassani, Saeed; Latibari, Ahmad Jahan; Ozbay, Gunay
Among forest diseases, fungi are the most important agents that cause irreparable losses to the wood of standing trees and logs. In this study, pyrolysis of undecayed and decayed beech (Fagus orientalis) wood were carried out using a fixed-bed reactor at pyrolysis temperature of 500 degrees C in nitrogen atmosphere. The influence of Trametes versicolor fungal decay on the yield and chemical composition of products was investigated. The bio-oil yield was 62.5 wt% at a pyrolysis temperature of 500 degrees C for decayed wood, while the bio-oil yield was found to be about 58 wt% at the same temperature for undecayed wood. Bio-oils were characterized using some chromatographic and spectroscopic techniques, such as gas chromatography-mass spectrometry (GC/MS). It was found that Tetracosamethyl-cyclododecasiloxane (5.50%), tetradecamethyl-hexasiloxane (4.85%), 2,6-dimethoxy-phenol (4.21%), and benzene acetic acid (3.16%) were the main oil components present in decayed beech wood, while syringol (14.86%), methoxyeugenol (6.59%), naphthalene (4.41%), o-guaiacol (3.60%), isoeugenol (3.17%), and 2-methoxy-4-methyl-phenol (3.08%) were present in undecayed beech wood. These results show that decayed wood can be used for the production of bio-oil.
The effect of heat treatment on bio-oil properties obtained from pyrolysis of wood sawdust
(Springer, 2015) Ozbay, Gunay; Pekgozlu, Ayben Kilic; Ozcifci, Ayhan
Heat treatment is becoming increasingly popular and is growing as an industrial process to improve wood properties. The Finnish wood heat treatment technology, ThermoWood, is the most commonly used technology in the industrial area. In this study, pyrolysis of untreated and heat-treated ash wood (Fraxinus excelsior L.) was carried out using a fixed-bed reactor at different pyrolysis temperatures. The influences of the heat treatment process and the pyrolysis temperature on the yields and chemical composition of products were investigated. The maximum bio-oil yield was 46 wt% at a pyrolysis temperature of 550 degrees C for untreated wood, while the biooil yield was found to be about 41 wt% at a pyrolysis temperature of 500 degrees C for heat-treated wood. The elemental composition and higher heating value (HHV) of the bio-oil was determined. The chemical composition of the bio-oil was investigated using some chromatographic and spectroscopic methods, such as gas chromatography-mass spectrometry (GC/MS) and 1 H-NMR. It was found that the heat treatment process significantly reduced the organic acids, ketones and aldehydes, while it increased the phenolic compounds. These results show that heat-treated wood sawdust should be used as a valuable feedstock for production of the bio-oil.
Effects of Catalysts on Modulus of Rupture and Chemical Structure of Heat-Treated Wood
(Zagreb Univ, Fac Forestry, 2018) Ozcifci, Ayhan; Kokten, Erkan Sami; Ayrilmis, Nadir; Ozbay, Gunay; Altun, Suat
Heat treatment process, which is widely used in the wood industry, has shown some negative effects on the mechanical strength of wood. The objective of this study was to investigate the effects of catalysts on the modulus of rupture (MOR), mass loss and chemical structure of heat-treated Scotch pine (Pinus sylvestris L.) samples. For this purpose, some catalysts (50 % NaOH and 47 % KOH solutions, solid KOH) were added to the heat treatment process. Heat treatment experiments were performed under the nitrogen atmosphere at the temperature of 212 degrees C for 2 h. The MOR and chemical changes monitored by FT-IR spectra were then examined for the test groups. According to the results of this study, the use of commercial solid potassium hydroxide (KOH) in heat treatment decreased the degree of strength loss and mass loss of heat-treated wood. The strength (MOR) loss of samples heat-treated in the presence of potassium hydroxide was found to be only 5.4 %, while the strength loss in non-catalytic treatment was found to be 12.5 %.
EFFECTS OF SOME IMPREGNATION CHEMICALS ON COMBUSTION CHARACTERISTICS OF LAMINATED VENEER LUMBER (LVL) PRODUCED WITH OAK AND POPLAR VENEERS
(North Carolina State Univ Dept Wood & Paper Sci, 2010) Kol, Hamiyet Sahin; Ozbay, Gunay; Kose, Lutfu; Kurt, Seref
The objective of this research was to investigate the effects of impregnation chemicals on the combustion properties of 3-ply laminated veneer lumber (LVL) made of Oak (Quercus petraea subsp. Iberica) and Poplar (Populus tremula L.). For this purpose, oak wood was used as the outer ply and poplar used for the core ply in LVL. Borax (BX), boric acid (BA), borax+boric acid (BX+BA), and di-ammonium phosphate (DAP) were used as impregnation chemicals, and urea formaldehyde (UF), phenol formaldehyde (PF), and melamine-urea-formaldehyde (MUF) adhesives as bonding agent were used to produce LVLs. The vacuum pressure method was used for the impregnation process. The combustion test was performed according to the procedure defined in the ASTM-E 69 standards, and during the test the mass reduction, temperature, and released gas (CO, O-2) were determined for each 30 seconds. As a result, di-ammonium phosphate was found to be the most successful fire retardant chemical in LVL with MUF adhesive. LVL produced from a combination of oak and poplar veneers with MUF adhesive and impregnated with DAP can be recommended to be used as a fire resistant building material where required.
IMPACTS OF BLEACHING CHEMICALS AND OUTDOOR EXPOSURE ON CHANGES IN THE COLOR OF SOME VARNISHED WOODS
(North Carolina State Univ Dept Wood & Paper Sci, 2010) Ozcifci, Ayhan; Ozbay, Gunay
This study was carried out to determine the changes of the surface color of Scots pine (Pinus sylvestris L.) and Oriental beech (Fagus orientalis Lipsky) woods after exterior conditioning. First, the samples were bleached with 25% NaOH and 17.5% H2O2. Afterwards, they were varnished with polyurethane and synthetic varnishes, and then they were exposed to exterior conditions for 12 months. Tests for color differences and metric chroma were done according to the ASTM D-2244 standard. It was deduced that exposure to exterior conditions causes color differences in samples, while bleaching with the given solution reduces that effects, and reverts the surface color to that of the natural control specimens. However, bleached specimens exposed to 12 months exterior conditioning had more discoloration than those of natural control samples. In conclusion, if the wood materials will be exposed to outdoors after bleaching, finishing process should be applied to surfaces in order to prevent further color change.
Modeling of Bio-Oil Production by Pyrolysis of Woody Biomass: Artificial Neural Network Approach
(Gazi Univ, 2020) Ozbay, Gunay; Kokten, Erkan Sami
This study is dedicated to developing a reliable artificial neural network (ANN) model to model the pyrolysis liquid product (bio-oil). Some related parameters with the bio-oil yield such as the pyrolysis temperature, duration, catalyst type, catalyst ratio, particle size, proximate, and ultimate analysis of the biomass were tested. Due to the different characteristics of different biomass types and pyrolysis methods, only slow and intermediate pyrolysis data from woody biomass were used in modeling. The correlation coefficients (R) were 0.992, 0.933, and 0.951 for training, validation, and testing, respectively. In order to evaluate the predictability of the ANN model, the predicted results were compared with the experimental results that were not introduced before. The simulated data were in good agreement with the experimental results indicating the reliability of the developed model. The relative impact results revealed that the most important parameter that affects the bio-oil yield was catalyst type (11.4%).
The pyrolysis characteristics of wood waste containing different types of varnishes
(Tubitak Scientific & Technological Research Council Turkey, 2016) Ozbay, Gunay; Ozcifci, Ayhan; Kokten, Erkan Sami
The wood industry produces large amounts of wood waste. This waste usually contains a number of nonwood materials, such as paints or varnishes. In this study, the pyrolysis characteristics of wood waste containing synthetic, polyurethane, and polyester varnishes were investigated for conversion into renewable liquid fuels. The elemental analysis and higher heating values of the bio-oils were determined. The chemical compounds present in the bio-oils obtained at an optimum temperature were identified by gas chromatography/mass spectroscopy analysis. The product yields and compositions were affected by the types of varnishes. The maximum bio-oil yield of 46.7% was obtained from pyrolysis of waste wood containing polyester varnish at a final pyrolysis temperature of 500 degrees C. The bio-oil produced from wood waste containing varnishes was composed mainly of phenols, aldehydes, acids, ketones, alcohols, benzenes, and N-containing compounds. The phenols accounted for the largest amount of compounds in the bio-oils. Therefore, the bio-oil produced from varnished wood waste could be a potential substitute for biofuels and green chemicals.
Pyrolysis of Firwood (Abies bornmulleriana Mattf.) Sawdust: Characterization of Bio-Oil and Bio-Char
(Zagreb Univ, Fac Forestry, 2015) Ozbay, Gunay
This paper describes the research of slow pyrolysis of firwood (Abies bornmulleriana Mattf.) sawdust by using fixed-bed reactor. The effect of temperature ranging between 350 and 600 degrees C on gas, liquid and solid products was examined. The maximum bio-oil yield of 45.9 % was obtained at the final pyrolysis temperature of 500 degrees C. The elemental analysis and heating value of bio-oil and bio-char were determined, and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques such as Gas Chromatography-Mass Spectrometry (GC/MS) and Proton Nuclear Magnetic Resonance (H-1-NMR). The liquid product was mainly composed of phenolics, including 2-methoxy-phenol, 2-methyl-phenol, phenol, as well as aldeyhdes, acids, esters, alcohols and ketones. The chemical characterization has shown that the bio-oil obtained from residues of forestry production, such as firwood sawdust, can be used as an environmental feedstock, which is an ideal candidate for alternative fuels. Moreover the bio-char can be used as an energy source and active carbon.
Pyrolysis of goat manure to produce bio-oil
(Elsevier - Division Reed Elsevier India Pvt Ltd, 2019) Erdogdu, Ahmet Emrah; Polat, Refik; Ozbay, Gunay
In this paper, biomass in goat manure form is pyrolyzed by a fixed-bed reactor. The influence of the temperature within the range of 300-600 degrees C is to be detected in solid, liquid and gas products. Different product yields emerge according to the pyrolysis temperature. At 500 degrees C, the product yield reaches the maximum valuation, the bio-oil obtained at this temperature is analyzed via gas chromatography and mass spectrometry (GC/MS) and elemental analysis. The highest efficiency of the bio-oil reached at 26.1% by weight at 500 degrees C. As a result of the TGA analysis, it was observed that the maximum separation rate was between 250 and 500 degrees C and the conversion was complete at about 600 degrees C. Elemental analysis proved that the amount of oxygen in the bio-oil was 23.15% and carbon was 51.75%, while the amount of oxygen in the raw material was 39.85% and carbon was 42.08%. In addition, the pH value of the bio-oil was 4.12. Bio-oil combination product involves organic compounds for instance, benzenes, alcohols, alkanes, alkenes, ketones, phenols and polyaromatic hydrocarbons (PAHs). These results depict goat manure can be used as a precious raw material in bio-oil production. (C) 2018 Karabuk University. Publishing services by Elsevier B.V.
SHEAR STRENGTH OF HEAT-TREATED TALI (ERYTHROPHLEUM IVORENSE) AND IROKO (CHLOROPHORA EXCELSA) WOODS, BONDED WITH VARIOUS ADHESIVES
(North Carolina State Univ Dept Wood & Paper Sci, 2009) Kol, Hamiyet Sahin; Ozbay, Gunay; Altun, Suat
The aim of this study was to evaluate the effect of heat treatment on the shear strength of tali (Erythrophleum ivorense) and iroko (Chlorophora excelsa) woods, bonded with some structural adhesives. Shear strength of untreated and heat-treated woods bonded with phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), melamine-formaldehyde (MF), and polyurethane (PUR) adhesives was studied. An industrial heat treatment method (ThermoWood) was used. The timbers were thermally modified for 2 hours at 180 degrees C. Laminated samples having two sample sets were prepared from untreated and heat-treated wood for the shear strength test. The results of the tests showed that the heat treatment affected shear strength of laminated wood negatively. Although there was a considerable difference in adhesive bond shear strength between untreated and treated wood, both wood species bonded with the adhesives fulfilled the required value for shear strength of the adhesive bonds. PF, MUF, MF, and PUR adhesives performed in a rather similar way for both wood species.
SYNTHESIS AND CHARACTERIZATION OF RESOL TYPE PHENOL-FORMALDEHYDE RESIN IMPROVED BY SIO2-NP
(Slovak Forest Products Research Inst, 2021) Ozbay, Gunay; Kokten, Erkan Sami; Ozcifci, Ayhan
In this work, resol type phenol-formaldehyde (RPF) resin was modified with silicon dioxide nanoparticles (SiO2-Np). SiO2-Np was added at varying ratios from 1 to 4 wt.% to improve the bonding performance of the RPF resins. The physical characteristics of the nano-modified RPF (nano-RPF) resins were examined. The effects of modification were studied by Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The results of FT-IR revealed that the nano-RPF resins were successfully produced by phenol, formaldehyde, and SiO2-Np. The nano-RPF resins demonstrated high thermal stability at temperatures above 500 degrees C. The adhesive performance of the nano-RPF resins was investigated under dry and wet conditions. The nano-RPF resins indicated better adhesive performance than unmodified RPF resin. The RPF resin could be improved by SiO2-Np.
Synthesis of Bio-Oil-phenol-Formaldehyde Resins under Alkali Conditions: Physical, Chemical and Thermal Properties of Resins and Bonding Performance
(Zagreb Univ, Fac Forestry, 2020) Ozbay, Gunay; Cekic, Caglar; Ahmad, Muhammad Syarhabil; Kokten, Erkan Sami
In the present study, bio-oil produced from vacuum pyrolysis of woody biomass has been investigated as a source of chemical feedstock. Bio-based resins were produced using the bio-oil with phenol substitutions ranging from 10 to 30 wt%. The conventional GC/MS analysis was carried out for the evaluation of the chemical composition of bio-oil. TGA, DSC and FT-IR analyses were used in order to characterize the bio-oil-phenol-formaldehyde (BPF) resins. The bonding quality of wood samples bonded with the BPF resins was investigated under different pre-treatment conditions. The highest shear strength was observed for the control samples bonded with the laboratory PF resin. As the amount of bio-oil was increased up to 30 wt%, the shear strength of the samples decreased from 12.08 to 11.76 N/mm(2). The bonding performance was not negatively affected by the combination of bio-oil under dry conditions. According to TS EN 12765 standard, the relevant performance requirements for bonded samples under dry conditions must be at least 10 N/mm(2). Relating to the standard, all samples bonded with BPF resins obtained the requirements for durability class C1. Under wet conditions, the bonding performance was negatively affected by the addition of bio-oil. However, the BPF resins fulfilled the durability requirements for C1, C2, and C3 specified in EN 12765 (2002).
Synthesis of biobased phenolic resins using catalytic pyrolysis oil and its effect on oriented strand board performance
(Taylor & Francis Ltd, 2020) KOKTEN, Erkan Sami; Ozbay, Gunay; Ayrilmis, Nadir
The aim of this work is to investigate the chemical, physical, thermal and mechanical properties of bio-oil-phenol-formaldehyde (BPF) resin synthesized with catalytic pyrolysis oil. In this way, catalysed and uncatalysed pyrolysis processes were carried out in a vacuum pyrolysis reactor at the temperature of 500 degrees C. Sodium hydroxide (NaOH) and potassium hydroxide (KOH) were used as catalysts in the catalysed pyrolysis processes. The BPF resins were synthesized using the bio-oil at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% phenol replacement levels. The chemical composition of the bio-oil was analyzed by GC/MS analysis. The thermal characteristics and chemical structures of the resins were characterized by TGA and FT-IR analysis, respectively. Physical properties including pH, viscosity, solid content and gel time of the resins were determined. Oriented Strand Board (OSB) were manufactured to evaluate the mechanical performances of modified resins. The BPF resins were successfully synthesized with phenol, bio-oil and formaldehyde. BPF resins synthesized with catalytic bio-oils showed better thermal stability than BPF resin synthesized with non-catalytic bio-oil. The mechanical test results showed that the IB strengths of OSBs made with BPF resins synthesized by use of NaOH exhibited better performance than OSBs commercial PF made.

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