Bodo Saake

Hamburg University | UHH · Chemical Wood Technology

This study explores the application of chemotaxonomic methods to trace the geographic origin of wood used in paper production. Utilizing thermal desorption gas chromatography-mass spectrometry (TD-GC-MS) and principal component analysis (PCA), distinct chemical profiles were identified in both hydrophobic and hydrophilic extracts. Residual wood ext...

This paper evaluates the modification of fiber morphology and the strength property development of paper from Enset fiber as a function of soda pulping conditions and refining energy. Soda pulping was conducted at pulping temperatures between 160 and 180 °C. The NaOH charge was 16, 20, and 24% based on the initial raw material. The beating of pulp...

This paper presents a comparative analysis of the blind test outcomes of two independent methods for the identification of tropical wood species in pulp and paper products. Both, the established anatomical and the relatively new chemotaxonomic method support the European Deforestation Regulation 2023/1115 (EUDR), which aims to ensure that only lega...

European paper mills are currently facing the question of whether recovered paper, their main raw material, will be available in sufficient quantities and an acceptable quality in the future. An alternative to recovered paper or wood fiber is the use of agricultural residues such as wheat straw. Sodium carbonate-based straw pulping processes have t...

The European Deforestation Regulation 2023/1115 (EUDR) prohibits trading of wood and wood products obtained from illegal logging on the EU market. While the identification of solid wood via anatomy, chemistry and genetics has already been established, there is a lack of identification methods for pulp and paper that complement anatomy. This publica...

Massive tonnes of fibrous residues are produced during the harvesting of the Enset plant for food preparation. The fibers are characterized by high cellulose and hemicellulose content and low lignin and extractive content. These make the fiber a good candidate for its concurrent valorization aimed at dissolving grade pulp and biogas. Prehydrolysis...

Enset fibrous residues are characterized by high carbohydrate, low lignin, and low extractive contents. These make the fiber a good candidate for its simultaneous valorization aimed at cellulose pulp and hemicellulose sugar recovery. An Integrated bio-refinery scheme using pre-hydrolysis stem treatment and subsequent soda pulping was used for this...

The aim of this study was the experimental demonstration and assessment of a novel lignocellulose biorefinery (LCB) for the integration of beech wood-based products as platform and fine chemicals. The process sequence included organosolv pulping followed by pulp bleaching, hydrothermal conversion of hemicellulose to xylose and its purification, fer...

Street tree pruning residues are a widely available and currently undervalorized bioresource. Their utilization could help alleviate an increasing biomass shortage and offset costs of the pruning process for the municipalities. In this work, a holistic valorization pathway of pruning residues leading to fibers, oligosaccharides, biogas, and compost...

The utilization of agricultural products and residues for the production of value-added and biobased products is a highly relevant topic in present research. Due to the natural recalcitrance of lignocellulosic biomass against enzymatic degradation, pretreatments are important requirement for further processes. For the raw material in this study, co...

Currently, most of the collected waste medium-density fiberboards (MDF) is incinerated or landfilled, as economically viable recycling methods are yet to be developed. By steam refining waste medium-density fiberboards (MDF), it is possible to hydrolyze the incorporated resins and isolate a high yield fiber fraction. Further refining of the steam t...

In this work, we present an approach to cross-link cellulose nanofibrils (CNFs) with various metallic cations (Fe³⁺, Al³⁺, Ca²⁺, and Mg²⁺) to produce inks suitable for three-dimensional (3D) printing application. The printability of each hydrogel ink was evaluated, and several parameters such as the optimal ratio of Mⁿ⁺:TOCNF:H2O were discussed. CN...

Maize, also called corn, is one of the most available feedstocks worldwide for lignocellulosic biorefineries. However, a permanent biomass supply over the year is essential for industrial biorefinery application. In that context, ensiling is a well-known agricultural application to produce durable animal feed for the whole year. In this study, ensi...

In this work, we present an approach to cross-link cellulose nanofibrils (CNFs) with various metallic cations (Fe ³⁺ , Al ³⁺ , Ca ²⁺ , and Mg ²⁺ ) to produce inks suitable for three-dimensional (3D) printing application. The printability of each hydrogel ink was evaluated, and several parameters such as the optimal ratio of M ⁿ⁺ :TOCNF:H 2 O were d...

Agricultural residues are promising and abundant feedstocks for the production of monomeric carbohydrates, which can be gained after pretreatment and enzymatic hydrolysis. These monomeric carbohydrates can be fermented to platform chemicals, like ethanol or succinic acid. Due to its high availability, corn stover is a feedstock of special interest...

In view of the expected increase in available waste medium-density fiberboard (MDF) and the current insufficient and unsatisfactory disposal capacities, efficient ways of recycling the waste material need to be developed. In this study, the potential of steam refining as a method to hydrolyze the resins, isolate fibers, and obtain a hemicellulose-r...

This paper investigates a strategy to convert hydrophilic cellulose nanofibrils (CNF) into a hydrophobic highly cross-linked network made of cellulose nanofibrils and inorganic nanoparticles. Firstly, the cellulose nanofibrils were chemically modified through an esterification reaction to produce a nanocellulose-based macroinitiator. Barium Titanat...

In recent years, subfossil oak has become increasingly popular, particularly in the manufacture of small wooden products. Due to the long period of its underground preservation, detailed knowledge of its properties is essential to properly use this material. In this study, subfossil oak samples dated to approximately 1000, 2000 and 3000 years BP an...

One of the major challengesin transforming from fossil to bio-based materialsis the production of biomass-derived intermediates in a well-described,reproducible manner at a relevant scale.Lignin, as the only renewable aromatic resource, will play an important role in the future bioeconomy.Various grades of lignin were produced at Fraunhofer CBP’spi...

The main aim of this investigation was to study the interaction of cationised xylans as antimicrobial substances with poly(ethylene terephthalate) (PET) model films, prepared by spin coating. A quartz crystal microbalance (QCM-D) with dissipation monitoring was applied as a nanogram sensitive balance to detect the amount of adsorbed cationised xyla...

Two commercial carboxymethyl celluloses (CMC) with degree of substitution (DS) 0.75 and 0.77, respectively, have been submitted to exhaustive methanolysis until the amount of the insoluble residue did not further decrease. Dissolved and insoluble material were determined gravimetrically and further analyzed with respect to their substituent distrib...

The paper presents the results of a German-Czech-Hungarian-Slovenian wood research consortium, dealing with wood modification techniques by using renewable modification agents for the outdoor use of local, originally non-durable modified wood species like beech, poplar and pine sapwood. Higher value assortments of naturally durable and dimensional...

Owing to superior mechanical properties, synthetic polymers like poly(ethylene terephthalate), polytetrafluorethylene, polypropylene, etc. keep an exceptional position in medical and technical fields. However, in many cases, their highly hydrophobic and inert surfaces represent an important drawback for many applications. Therefore, surface modific...

P nuclear magnetic resonance (NMR) spectroscopy is a common analytical approach for the quantitative determination of the different hydroxyl groups in technical lignins. However, the analysis of lignosulfonates with this method is more difficult due to solubility problems in the commonly used solvent systems. Hence, extensive derivatization procedu...

Herein, a novel synthesis of a fully renewable lignin-based building block equipped with cyclic carbonate functionalities is presented. In an efficient two-step procedure, organosolv lignin from ethanol–water pulping of beech wood is oxyalkylated with glycerol carbonate to insert adjacent hydroxyl groups. The oxyalkylated lignin is then reacted via...

Xylan is a highly available polysaccharide in the plant kingdom and is therefore a valuable resource for novel materials from renewable resources. Hydroxyalkylation is one of the most common reactions to derivatize biopolymers by altering hydroxyl groups. State of the art procedures incorporate epoxides, which are toxic, carcinogenic and highly exp...

The main aim of this research was development of thin functional xylan layers on polyethylene terephthalate (PET) fabric surfaces. Xylans, derived from hard wood and oat spelt, were modified chemically in order to introduce cationic functional groups. Cationization of xylans was proved by elemental analysis, total bound nitrogen determination, and...

Fucoidans are sulphated fucose-rich polysaccharides predominantly found in the cell walls of brown algae. The bioactive properties of fucoidans attract increasing interest from the medico-pharmaceutical industries and may drive an increase in demand of brown algae biomass. In nature, the biochemical composition of brown algae displays a seasonal fl...

The chemical structures obtained by the modification of arabinoxylans with the cyclic carbonates propylene carbonate (PC) and 4‐vinyl-1,3-dioxolan-2-one (VEC) with varying degrees of substitution were investigated. Therefore, a new analytical method was developed that is based on a microwave-assisted hydrolysis of the polysaccharides with trifluoro...

This study investigated the blending of unbleached wheat straw high yield MEA (monoethanolamine) pulp with recycled pulp to improve the strength properties of recycled pulp. First, the cooking temperature in MEA high yield pulping was stepwise reduced from 160 °C to 120 °C to enhance pulp yield as much as possible. The optimum temperature for the i...

Blending unbleached bagasse soda pulp with old corrugated container (OCC) pulp to reinforce the strength properties of the OCC is investigated. Firstly, bagasse pulp was collected from a local paper mill and the refining behaviour and strength development of this bagasse pulp was evaluated. The results demonstrated that application of up to 200 kW/...

Cellulose acetate (CA)-based materials, like cigarette filters, contribute to landscape pollution challenging municipal authorities and manufacturers. This study investigates the potential of enzymes to degrade CA and to be potentially incorporated into the respective materials, enhancing biodegradation. Deacetylation studies based on Liquid Chroma...

The structure and composition of a biobased polymer blend with wood like appearance was studied. The effects of processing time for mixing at 190 °C was investigated. The structure of the blend was unveiled combining fractionation techniques with size exclusion chromatography and nuclear magnetic resonance analysis. The material was found to be a b...

The synthetic versatility and the low toxicity of cyclic alkyl carbonates has driven a wider interest in their use to access new biobased and environmentally friendly polymer building blocks, especially as alkylating reagents. Here, we report for the first time, the synthesis of biobased polyols from lignins of different sources (hardwood, softwood...

This work focused on the enzymatic treatment of deinking sludge (DS), a waste stream arising from German deinked pulp mills. Three industrial DS samples were characterised with respect to chemical composition and fibre morphology. In this study, four cellulase enzyme preparations were tested under neutral pH conditions and one cellulase was identif...

The anticipated shortage and price increase of fossil resources rendered material applications of renewable resources especially lignocellulosics highly attractive. When using lignin for polymeric materials, the macromolecular nature of lignin can be retained to reduce synthesis efforts. However, the effective integration of lignin into polymers is...

Based on the results of this study, a total energy amount of 3,111 TJ/year can be produced from the anaerobic digestion of deinking sludge (DS) arising from German deinked pulp mills, which can then be used to replace up to 5% of the total energy demand for those mills. The DS examined was generated by flotation deinking at the laboratory scale fro...

Beech wood organosolv lignin was modified with propylene carbonate (PC) in an efficient, facile and solvent-free procedure without using highly toxic and explosive propylene oxide (PO). Comparative studies of the oxyalkylation procedure were performed varying crucial reaction conditions. The results of FTIR, ¹H NMR, ¹³C NMR and ³¹P NMR spectroscopi...

The transformation of lignocellulosic biomass into bio-based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached the commercial level, produces a high yield of an organic-rich liquid stream. Despite the recent efforts in elucidating the degradation paths of...

Around Denmark, Laminaria digitata and Saccharina latissima are particularly common macroalgae species and are considered as prospective candidates for biorefineries. In this study, the carbohydrate composition and protein levels of L. digitata and S. latissima from three different sites in Denmark were compared for 1 year, and compositional variat...

Since the opening in October 2012, the Fraunhofer-Center for Chemical-Biotechnological Processes has adapted and improved the fractionation of lignocellulosic feedstock into lignin, cellulose and hemicellulose-rich streams. This biorefinery concept is based on an Organosolv process using mixtures of water and ethanol. As lignin properties are gener...

The effect of processing temperature and time on polylactide/lignin blends was evaluated. Two blends, one commercial and one prepared mixing polylactide (PLA) with different lignin contents, were processed at 190 and 170 °C for different mixing times. The commercial blend was a blend of PLA with 5 mass% of soda lignin and 15.4 mass% of softwood whi...

The exact quantification of all carbohydrate constituents in wood and pulp is a challenge because of the various glycosidic linkages of the polysaccharides with different stabilities. The individual detector responses for the compounds in the hydrolysates additionally complicate the quantification as pure standards for 4-O-methyl-α-D-glucuronic aci...

Lytic polysaccharide monooxygenases (LPMOs) are a class of powerful oxidative enzymes that breakdown recalcitrant polysaccharides such as cellulose. Here we investigate the action of LPMOs on cellulose fibers. After enzymatic treatment and dispersion, LPMO-treated fibers show intense fibrillation. Cellulose structure modifications visualized at dif...

The surface chemistry and dispersion in poly(lactic-acid) of microfibrillated wood and microfibrillated lignocellulose prepared from untreated and partially delignified beech were compared with conventional microfibrillated cellulose produced from bleached pulp. High heterogeneity in fibril morphology and bulk chemical composition was observed. Als...

Lignin is a promising candidate for blends with thermoplastic polymers. Still, this endeavour is a challenge due to poor compatibility between both components. In this article, the effect of lignin esterification on the improvement of the compatibility between hardwood Kraft lignin and high-density polyethylene (PE-HD) is investigated. For this pur...

A novel synthesis for the incorporation of vinyl groups into the bio-polymer xylan is presented. For derivatization the cyclic organic carbonate 4-vinyl-1,3-dioxolan-2-one was used in DMSO under alkaline conditions. As a result xylans containing vinyl functionalities are obtained. This is increasing the reactivity, for example for radical induced r...

Persian wingnut, Persian honeylocust, Persian ironwood and Persian alder are of four endemic and important species of Hyrcanian forests that initial data about the presence of bioactive components in them are available, however no comprehensive study has been done about their chemical components yet. Furthermore, bioactive phenolics are more in kno...

Lignins from pulp mills and biorefineries will gain increasing commercial importance in the next years. Their utilisation in polyolefin blends is of growing research interest as it offers a value-added usage of lignin as well as substitution of non-renewable resources. However, the low compatibility of lignin and polyolefins restrains a satisfying...

A novel synthesis for the incorporation of vinyl groups into the bio-polymer xylan is presented. For derivatization the cyclic organic carbonate 4-vinyl-1,3-dioxolan-2-one was used in DMSO under alkaline conditions. As a result xylans containing vinyl functionalities are obtained. This is increasing the reactivity, for example for radical induced r...

A new route towards embedding fibrillated cellulose in a non-polar thermoset matrix without any use of organic solvent or chemical surface modification is presented. It is shown that microfibrillated lignocellulose made from cellulose with high residual lignin content is capable of stabilising an emulsion of unsaturated polyester resin in water due...

In this study, a steam refining process, optimized earlier with respect to carbohydrate yield, was used to extract lignins from non-debarked poplar wood from short growth plantations by enzymatic hydrolysis (EHL) and alkaline extraction (AEL) for the utilization in lignin-phenol-formaldehyde resins (LPF). Three different pretreatment conditions wer...

Biobased precursors for the production of carbon fibers could be a cheaper and more environmentally-friendly alternative to polyacrylonitrile. In line with the 7th Framework Project CARBOPREC, which gathers 14 partners coming from 7 different countries, novel precursors based on either cellulose or lignin are produced by integration of carbon nanot...

A facile approach to obtaining cellulose nanofiber-reinforced polystyrene with greatly improved mechanical performance compared to unreinforced polystyrene is presented. Cellulose nanofibers were obtained by mechanical fibrillation of partially de-lignified wood (MFLC) and compared to nanofibers obtained from bleached pulp (MFC). Residual hemicellu...

Two bacterial polysaccharide lyase (PL) family 7 alginate lyases (EC 4.2.2.-) from Sphingomonas sp. (SALy) and Flavobacterium sp. (FALy), respectively, were selected for heterologous, monocomponent expression in Escherichia coli. The thermal stability, pH, and temperature reaction optima and substrate preferences of the enzymes on different alginat...

Pinus pinaster wood was pulped in ethanol/water medium catalyzed with sulfuric acid, and lignin was recovered from the liquid phase by precipitation upon water addition. Lignin samples were characterized for composition and thermal properties. Lignin samples were reacted with selected esterification agents (butyric, isobutyric, or crotonic anhydrid...

The high-value utilization of lignins is the most prominent opportunity to enhance the competitiveness of lignocellulosic biorefineries and reduce dependence On fossil resources. The incorporation of lignin into phenol formaldehyde (LPF) resins represents a viable route toward this target. Due to its macromolecular nature, lignin could function as...

A new method for the chemical characterization of xylans is presented, to overcome the difficulties in quantification of 4-O-methyl-α-D-glucuronic acid (meGlcA). In this regard, the hydrolysis behavior of xylans from beech and birch wood was investigated to obtain the optimum conditions for hydrolysis, using sulfuric acid. Due to varying linkage st...

The solubility in water and carbohydrates/lignin composition after hydrolysis of wood welded by linear friction welding was studied. Welded beech (WB) and welded spruce (WS) were analyzed at welding times (Wt) of 1, 1.5, 2, 2.5, 3 s, and 2, 4, 6, 8, 10, 12 s, respectively. Scratched welded material was first extracted in water, dried, cryo-milled,...

The determination of the chemical composition of lignocellulosic material is a resource-consuming analytical challenge that usually requires several chromatography-based techniques. Minor cell wall components and degradation products are, therefore, often ignored. 1H NMR spectroscopy applied to acid hydrolysates offers a quicker and more complete m...

Xylan is an abundant polysaccharide consisting of xylose units and has gained a significant increase in research interest in the last decades. Hydroxyalkylation of xylan is a way of modifying xylans to achieve xylan ethers with better water solubility as well as to form materials which can be used for gels, films or packaging applications. In this...

Lignin-based benzoxazines are synthesized for the first time using organosolv lignin as the phenolic component and aniline or propargyl amine as the amine component through the Mannich condensation reaction. Acid-catalyzed phenolation of organosolv lignin is performed to increase the phenolic structure with the open ortho-position, which is a requi...