Toxic formaldehyde emissions, and the necessity to reduce the consumption of petrochemicals, stim... more Toxic formaldehyde emissions, and the necessity to reduce the consumption of petrochemicals, stimulates the development of environmentally friendly adhesives. The aim of this research was to study, for the first time, the possibility of using condensed tannins (CTs)-rich extracts from grey alder (Alnus incana) and black alder (Alnus glutinosa) bark in the production of particleboards and plywood adhesives. The chemical structure, composition, and molecular weight of the CTs were identified by a 13C-NMR and TOF-MS analysis. Three innovative adhesive systems were studied: CTs-phenol-formaldehyde (CTs-PF) resin; a CTs-polyethyleneimine (PEI) adhesive system; and CTs–PEI combined with an ultra-low emitting formaldehyde resin (ULEFR)—CTs–PEI–ULEFR. The results showed that CTs-PF resin has properties close to commercial PF resin, and the formaldehyde emission was twice lower. CTs–PEI bonded particleboards corresponded to the requirements of the EN 312:2010 standard for particleboards in d...
The objective of this work was the development of environmentally-friendly, sustainable adhesive ... more The objective of this work was the development of environmentally-friendly, sustainable adhesive systems for the manufacture of engineered wood products (mainly glulam) to replace synthetic adhesives made from petrochemicals. Lignin-based adhesive systems were proven to provide industrial glulam products with performance comparable to the products produced with conventional gluing systems. The application of this innovative adhesives technology is expected to provide environmental and cost benefits and to lead to higher demand for glulam products when carbon neutral building solutions are sought.
An alternative way to use lignins, is to break them down into smaller aromatic compounds. The Ene... more An alternative way to use lignins, is to break them down into smaller aromatic compounds. The Energy research Centre of the Netherlands (ECN) achieves this using pyrolysis technology, which converts BioligninTM into a phenolic pyrolysis oil. In BIOCORE, this oil has been tested by CHIMAR to make PF‐based adhesives, replacing a part (10 %) of the phenol component by pyrolysis oil. Results so far are promising and indicate that a greater proportion of pyrolysis oil could be used.
Conventional composites from wood and synthetic polymers, like particleboards, find many applicat... more Conventional composites from wood and synthetic polymers, like particleboards, find many applications in the construction and furniture sector. However, deforestation, global warming, the concern about adequate wood supplies in the long term, countries that have no land suitable for the development of forests, high volumes of unused agricultural wastes, accumulation of nondegradable plastics, and the unceasing interest of the consumers for new products, are some of the reasons that motivate scientists to seek alternative solutions to wood and petrochemical polymers. The most feasible solution so far seems to be the manufacturing of particleboards with materials from renewable resources that are also biodegradable. To this direction, various agricultural wastes, mostly from lignocellulosic crops like hemp, kenaf, jute, etc., but also residues from other cultivations like rye, rice, wheat, as well as grasses, have been successfully used in combination with biodegradable polymers from ...
Τα τελευταία χρόνια έχει ενταθεί η εκμετάλλευση φυσικών πόρων για παραγωγή χημικών προϊόντων, καυ... more Τα τελευταία χρόνια έχει ενταθεί η εκμετάλλευση φυσικών πόρων για παραγωγή χημικών προϊόντων, καυσίμων και ενέργειας. Αυτό προέκυψε από την ανάγκη μείωσης των εκπομπών αερίων του θερμοκηπίου, περιορισμού των αποβλήτων, εξοικονόμησης ορυκτών πόρων και δημιουργίας προϊόντων που είναι φιλικά προς τον άνθρωπο και το οικοσύστημα. Έτσι δημιουργήθηκε μια νέα μορφή οικονομίας, η βιο-οικονομία, η οποία προσφέρει τη δυνατότητα δημιουργίας νέας επιχειρηματικότητας και θέσεων εργασίας.Το ξύλο διαδραματίζει βασικό ρόλο στη βιο-οικονομία όχι μόνο επειδή παρέχει πολλά από τα αγαθά της καθημερινής ζωής αλλά και επειδή είναι μια καλή πηγή για παραγωγή ποικιλίας χημικών ενώσεων και καυσίμων που λαμβάνονται από αυτό μέσω της διεργασίας της βιο-διΰλισης. Ωστόσο, η ευρεία χρήση του ξύλου μαζί με την ταχεία ανάπτυξη του παγκόσμιου πληθυσμού δημιουργούν σοβαρές ανησυχίες στις βιομηχανίες ξύλου και ξυλοσανίδων (όπως πχ μοριοσανίδες, MDF, OSB, κόντρα πλακέ κλπ.) σχετικά με τη μακροπρόθεσμη επάρκειά του και ...
Abstract Phenol-formaldehyde (PF) resins are widely used in wood-based applications by reason of ... more Abstract Phenol-formaldehyde (PF) resins are widely used in wood-based applications by reason of their heat and water resistance, high mechanical strength and chemical stability. Challenges regarding the environmental impact of petroleum-based resources lead to an increased interest of developing new resins where components such as phenol are replaced with renewable materials. This work evaluates the environmental impact of phenol-formaldehyde resins using an organosolv lignin as phenol replacement. Two life cycle analysis (LCA) boundaries (i.e. Cradle-to-Gate, Gate-to-Gate) are studied for PF resin having different substitution levels of phenol: 0%, 40% and 100%. The LC Soft (ICAS) is used for the LCA, which provides information regarding the carbon footprint (CF), fifteen environmental impact categories (e.g.: soil, water, air, human toxicity) and the life cycle inventory (LCI) contribution. The results show improvements for all environmental impact categories for the lignin substituted resins compared to PF resin, confirming the significant role of lignin. Moreover, the impact of the raw materials (Cradle-to-Gate) is significantly higher than the impact of the production process (Gate-to-Gate).
Scientists today are intensively seeking alternatives to petrochemical materials. Among others, l... more Scientists today are intensively seeking alternatives to petrochemical materials. Among others, lignin is a promising candidate because it is available in large quantities while its chemical structure makes its use possible in a variety of chemical reactions. Lignin, received by numerous methods from various feedstocks, is a promising material for the synthesis of many products like active carbon, thermosetting and thermoplastic polymers, surfactants, phenolic chemicals, etc. In this paper, the potential of using Biolignin – a trademarked organosolv lignin from straw prepared by Compagnie Industrielle de la Matière Végétale (CIMV; Neuilly-sur-Seine, France) – in the synthesis of phenol-formaldehyde (PF) resins was studied by CHIMAR HELLAS S.A. (Kalamaria, Greece). Before its use, Biolignin was further purified and subjected to mechanical treatment for the reduction of its particle size in order to increase its reactivity. The effectiveness of the treatment was verified by atomic for...
The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successful... more The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successfully applied for acidification of urea-formaldehyde (UF) resins. The resins were synthesized at a laboratory scale and characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The bonding ability of the resins was tested through the preparation of particle boards (PBs). It was found that the UF resins prepared with AQcatPy as acidification medium have a similar performance to typical UF resins, where conventional chemicals like formic acid (FA) or acetic acid (AA) serve for pH adjustments. The new resins give PBs with somewhat improved thickness swelling (TS) values, while all other properties are at the same level.
To increase the share of biomass for renewable energy in Europe conversion pathways which are eco... more To increase the share of biomass for renewable energy in Europe conversion pathways which are economic, flexible in feedstock and energy efficient are needed. The BioBoost project concentrates on dry and wet residual biomass and wastes as feedstock for de-central conversion by fast pyrolysis, catalytic pyrolysis and hydrothermal carbonization to the intermediate energy carriers oil, coal or slurry. Based on straw the energy density increases from 2 to 20-31 GJ/m3, enabling central GW scale gasification plants for bio-fuel production. The catalytic pyrolysis reduces oxygenates in the oil enabling power and refinery applications. The fast pyrolysis and HTC processes of demo-size are optimized for feedstock flexibility, yield, quality and further up-scaling is studied. A logistic model for feedstock supply and connection of de-central with central conversion is set up and validated allowing the determination of costs, the number and location of de-central and central sites. Techno/econ...
ABSTRACT Lignocellulosic crops like kenaf, flax and hemp have been extensively studied the last y... more ABSTRACT Lignocellulosic crops like kenaf, flax and hemp have been extensively studied the last years with the help of new technology and many new products fabricated with them are ready for the market or have already been marketed. Both the core material and the bast fibers of these crops are ideal feedstocks for the production of yarns and paper of high quality, for rendering flame retardant properties to composites reinforced with them, for the production of energy via a sustainable way without polluting the environment and for use as alternative materials to wood for the manufacturing of panels like particleboards and fiber boards (MDF, HDF, etc.). The investigation of lignocellulosic feedstock as potential source for the sustainable production of materials, products and energy has resulted in promising solutions for the successful replacement of their counterparts made from fossil raw materials. However, the related industries still have some challenges to face, like the cost of materials from lignocellulosic plants in comparison with those derived from fossil sources and the availability of the feedstock throughout the year.
ABSTRACT In the recent years, the research about the use of natural cellulosic fibers as substitu... more ABSTRACT In the recent years, the research about the use of natural cellulosic fibers as substitutes of the synthetic fibers (glass, aramid and carbon) used in the reinforcement of polymers, has been increased due to their biodegradability, lightness, reduced cost and favorable mechanical properties. Green composites are a particular class of biocomposites in which a biodegradable polymeric material is reinforced with natural fibers and represent a growing field in polymer technology. Such biodegradable polymers are usually aliphatic polyesters. The final properties of the composites are mainly depended on the kind of the fibers used, their aspect ratio, their volume fraction and orientation, and the adhesion strength on the fiber-matrix interface. Hence, one of the challenges that researchers face today is to achieve satisfactory interfacial bonding which will result in products with better mechanical properties. Such composites could find more industrial applications and consequently would have greater commercial acceptance. However, this is difficult due to the hydrophilicity of the fibers and the hydrophobicity of used polyesters. In the particular review the advances on the preparation of green composites with bast fibers and aliphatic polyesters are discussed. Emphases are given on the summary of the literature and presentation of the effect of the different kinds of bast fibers on the final products. The treatments used to improve the properties of the aliphatic polyesters in order for the final composites to perform advanced mechanical and thermal properties as well as biodegradability are also reviewed.
ABSTRACT In this study, an experimental phenol–formaldehyde resin with 20% phenol replacement by ... more ABSTRACT In this study, an experimental phenol–formaldehyde resin with 20% phenol replacement by cashew nut shell liquid (CNSL) was studied and compared with a conventional phenol–formaldehyde resin synthesized totally from petrochemical raw materials. The resins were characterized with standard lab analysis for their physicochemical specifications, while their thermal properties were studied with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). For comparison reasons pure CNSL and wood were also included in the TGA study. A DSC study conducted both for the neat resins and the system wood–resin as to examine the effect of wood on the curing performance of the resins in the real time conditions of their usage at the wood-based panels industry.The adhesion strength of these resins was investigated by their application in plywood production. The plywood panels were tested for their shear strength and wood failure performance while their free formaldehyde emissions were determined with the desiccator method. It was proved that although the neat CNSL modified PF resin (PCF) cures at longer time and higher temperature than a conventional PF resin, wood affects it more significantly, resulting in the evening of their curing performance. This is a novel finding that manifests the possibility of replacing a convention PF resin by a CNSL modified one in the plywood production, without changing any of their production conditions and with improvement to their overall properties.
Toxic formaldehyde emissions, and the necessity to reduce the consumption of petrochemicals, stim... more Toxic formaldehyde emissions, and the necessity to reduce the consumption of petrochemicals, stimulates the development of environmentally friendly adhesives. The aim of this research was to study, for the first time, the possibility of using condensed tannins (CTs)-rich extracts from grey alder (Alnus incana) and black alder (Alnus glutinosa) bark in the production of particleboards and plywood adhesives. The chemical structure, composition, and molecular weight of the CTs were identified by a 13C-NMR and TOF-MS analysis. Three innovative adhesive systems were studied: CTs-phenol-formaldehyde (CTs-PF) resin; a CTs-polyethyleneimine (PEI) adhesive system; and CTs–PEI combined with an ultra-low emitting formaldehyde resin (ULEFR)—CTs–PEI–ULEFR. The results showed that CTs-PF resin has properties close to commercial PF resin, and the formaldehyde emission was twice lower. CTs–PEI bonded particleboards corresponded to the requirements of the EN 312:2010 standard for particleboards in d...
The objective of this work was the development of environmentally-friendly, sustainable adhesive ... more The objective of this work was the development of environmentally-friendly, sustainable adhesive systems for the manufacture of engineered wood products (mainly glulam) to replace synthetic adhesives made from petrochemicals. Lignin-based adhesive systems were proven to provide industrial glulam products with performance comparable to the products produced with conventional gluing systems. The application of this innovative adhesives technology is expected to provide environmental and cost benefits and to lead to higher demand for glulam products when carbon neutral building solutions are sought.
An alternative way to use lignins, is to break them down into smaller aromatic compounds. The Ene... more An alternative way to use lignins, is to break them down into smaller aromatic compounds. The Energy research Centre of the Netherlands (ECN) achieves this using pyrolysis technology, which converts BioligninTM into a phenolic pyrolysis oil. In BIOCORE, this oil has been tested by CHIMAR to make PF‐based adhesives, replacing a part (10 %) of the phenol component by pyrolysis oil. Results so far are promising and indicate that a greater proportion of pyrolysis oil could be used.
Conventional composites from wood and synthetic polymers, like particleboards, find many applicat... more Conventional composites from wood and synthetic polymers, like particleboards, find many applications in the construction and furniture sector. However, deforestation, global warming, the concern about adequate wood supplies in the long term, countries that have no land suitable for the development of forests, high volumes of unused agricultural wastes, accumulation of nondegradable plastics, and the unceasing interest of the consumers for new products, are some of the reasons that motivate scientists to seek alternative solutions to wood and petrochemical polymers. The most feasible solution so far seems to be the manufacturing of particleboards with materials from renewable resources that are also biodegradable. To this direction, various agricultural wastes, mostly from lignocellulosic crops like hemp, kenaf, jute, etc., but also residues from other cultivations like rye, rice, wheat, as well as grasses, have been successfully used in combination with biodegradable polymers from ...
Τα τελευταία χρόνια έχει ενταθεί η εκμετάλλευση φυσικών πόρων για παραγωγή χημικών προϊόντων, καυ... more Τα τελευταία χρόνια έχει ενταθεί η εκμετάλλευση φυσικών πόρων για παραγωγή χημικών προϊόντων, καυσίμων και ενέργειας. Αυτό προέκυψε από την ανάγκη μείωσης των εκπομπών αερίων του θερμοκηπίου, περιορισμού των αποβλήτων, εξοικονόμησης ορυκτών πόρων και δημιουργίας προϊόντων που είναι φιλικά προς τον άνθρωπο και το οικοσύστημα. Έτσι δημιουργήθηκε μια νέα μορφή οικονομίας, η βιο-οικονομία, η οποία προσφέρει τη δυνατότητα δημιουργίας νέας επιχειρηματικότητας και θέσεων εργασίας.Το ξύλο διαδραματίζει βασικό ρόλο στη βιο-οικονομία όχι μόνο επειδή παρέχει πολλά από τα αγαθά της καθημερινής ζωής αλλά και επειδή είναι μια καλή πηγή για παραγωγή ποικιλίας χημικών ενώσεων και καυσίμων που λαμβάνονται από αυτό μέσω της διεργασίας της βιο-διΰλισης. Ωστόσο, η ευρεία χρήση του ξύλου μαζί με την ταχεία ανάπτυξη του παγκόσμιου πληθυσμού δημιουργούν σοβαρές ανησυχίες στις βιομηχανίες ξύλου και ξυλοσανίδων (όπως πχ μοριοσανίδες, MDF, OSB, κόντρα πλακέ κλπ.) σχετικά με τη μακροπρόθεσμη επάρκειά του και ...
Abstract Phenol-formaldehyde (PF) resins are widely used in wood-based applications by reason of ... more Abstract Phenol-formaldehyde (PF) resins are widely used in wood-based applications by reason of their heat and water resistance, high mechanical strength and chemical stability. Challenges regarding the environmental impact of petroleum-based resources lead to an increased interest of developing new resins where components such as phenol are replaced with renewable materials. This work evaluates the environmental impact of phenol-formaldehyde resins using an organosolv lignin as phenol replacement. Two life cycle analysis (LCA) boundaries (i.e. Cradle-to-Gate, Gate-to-Gate) are studied for PF resin having different substitution levels of phenol: 0%, 40% and 100%. The LC Soft (ICAS) is used for the LCA, which provides information regarding the carbon footprint (CF), fifteen environmental impact categories (e.g.: soil, water, air, human toxicity) and the life cycle inventory (LCI) contribution. The results show improvements for all environmental impact categories for the lignin substituted resins compared to PF resin, confirming the significant role of lignin. Moreover, the impact of the raw materials (Cradle-to-Gate) is significantly higher than the impact of the production process (Gate-to-Gate).
Scientists today are intensively seeking alternatives to petrochemical materials. Among others, l... more Scientists today are intensively seeking alternatives to petrochemical materials. Among others, lignin is a promising candidate because it is available in large quantities while its chemical structure makes its use possible in a variety of chemical reactions. Lignin, received by numerous methods from various feedstocks, is a promising material for the synthesis of many products like active carbon, thermosetting and thermoplastic polymers, surfactants, phenolic chemicals, etc. In this paper, the potential of using Biolignin – a trademarked organosolv lignin from straw prepared by Compagnie Industrielle de la Matière Végétale (CIMV; Neuilly-sur-Seine, France) – in the synthesis of phenol-formaldehyde (PF) resins was studied by CHIMAR HELLAS S.A. (Kalamaria, Greece). Before its use, Biolignin was further purified and subjected to mechanical treatment for the reduction of its particle size in order to increase its reactivity. The effectiveness of the treatment was verified by atomic for...
The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successful... more The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successfully applied for acidification of urea-formaldehyde (UF) resins. The resins were synthesized at a laboratory scale and characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The bonding ability of the resins was tested through the preparation of particle boards (PBs). It was found that the UF resins prepared with AQcatPy as acidification medium have a similar performance to typical UF resins, where conventional chemicals like formic acid (FA) or acetic acid (AA) serve for pH adjustments. The new resins give PBs with somewhat improved thickness swelling (TS) values, while all other properties are at the same level.
To increase the share of biomass for renewable energy in Europe conversion pathways which are eco... more To increase the share of biomass for renewable energy in Europe conversion pathways which are economic, flexible in feedstock and energy efficient are needed. The BioBoost project concentrates on dry and wet residual biomass and wastes as feedstock for de-central conversion by fast pyrolysis, catalytic pyrolysis and hydrothermal carbonization to the intermediate energy carriers oil, coal or slurry. Based on straw the energy density increases from 2 to 20-31 GJ/m3, enabling central GW scale gasification plants for bio-fuel production. The catalytic pyrolysis reduces oxygenates in the oil enabling power and refinery applications. The fast pyrolysis and HTC processes of demo-size are optimized for feedstock flexibility, yield, quality and further up-scaling is studied. A logistic model for feedstock supply and connection of de-central with central conversion is set up and validated allowing the determination of costs, the number and location of de-central and central sites. Techno/econ...
ABSTRACT Lignocellulosic crops like kenaf, flax and hemp have been extensively studied the last y... more ABSTRACT Lignocellulosic crops like kenaf, flax and hemp have been extensively studied the last years with the help of new technology and many new products fabricated with them are ready for the market or have already been marketed. Both the core material and the bast fibers of these crops are ideal feedstocks for the production of yarns and paper of high quality, for rendering flame retardant properties to composites reinforced with them, for the production of energy via a sustainable way without polluting the environment and for use as alternative materials to wood for the manufacturing of panels like particleboards and fiber boards (MDF, HDF, etc.). The investigation of lignocellulosic feedstock as potential source for the sustainable production of materials, products and energy has resulted in promising solutions for the successful replacement of their counterparts made from fossil raw materials. However, the related industries still have some challenges to face, like the cost of materials from lignocellulosic plants in comparison with those derived from fossil sources and the availability of the feedstock throughout the year.
ABSTRACT In the recent years, the research about the use of natural cellulosic fibers as substitu... more ABSTRACT In the recent years, the research about the use of natural cellulosic fibers as substitutes of the synthetic fibers (glass, aramid and carbon) used in the reinforcement of polymers, has been increased due to their biodegradability, lightness, reduced cost and favorable mechanical properties. Green composites are a particular class of biocomposites in which a biodegradable polymeric material is reinforced with natural fibers and represent a growing field in polymer technology. Such biodegradable polymers are usually aliphatic polyesters. The final properties of the composites are mainly depended on the kind of the fibers used, their aspect ratio, their volume fraction and orientation, and the adhesion strength on the fiber-matrix interface. Hence, one of the challenges that researchers face today is to achieve satisfactory interfacial bonding which will result in products with better mechanical properties. Such composites could find more industrial applications and consequently would have greater commercial acceptance. However, this is difficult due to the hydrophilicity of the fibers and the hydrophobicity of used polyesters. In the particular review the advances on the preparation of green composites with bast fibers and aliphatic polyesters are discussed. Emphases are given on the summary of the literature and presentation of the effect of the different kinds of bast fibers on the final products. The treatments used to improve the properties of the aliphatic polyesters in order for the final composites to perform advanced mechanical and thermal properties as well as biodegradability are also reviewed.
ABSTRACT In this study, an experimental phenol–formaldehyde resin with 20% phenol replacement by ... more ABSTRACT In this study, an experimental phenol–formaldehyde resin with 20% phenol replacement by cashew nut shell liquid (CNSL) was studied and compared with a conventional phenol–formaldehyde resin synthesized totally from petrochemical raw materials. The resins were characterized with standard lab analysis for their physicochemical specifications, while their thermal properties were studied with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). For comparison reasons pure CNSL and wood were also included in the TGA study. A DSC study conducted both for the neat resins and the system wood–resin as to examine the effect of wood on the curing performance of the resins in the real time conditions of their usage at the wood-based panels industry.The adhesion strength of these resins was investigated by their application in plywood production. The plywood panels were tested for their shear strength and wood failure performance while their free formaldehyde emissions were determined with the desiccator method. It was proved that although the neat CNSL modified PF resin (PCF) cures at longer time and higher temperature than a conventional PF resin, wood affects it more significantly, resulting in the evening of their curing performance. This is a novel finding that manifests the possibility of replacing a convention PF resin by a CNSL modified one in the plywood production, without changing any of their production conditions and with improvement to their overall properties.
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Papers by Electra Papadopoulou