Preliminary Study of the Biorefinery Concept to Obtain Furfural and Binder-less Panels from Hemp (Cannabis Sativa L.) Shives

AbstractThe objective of the study was to investigate the preliminary technological parameters for obtaining furfural and binder-less panels depending on hydrothermal pre-treatment temperature, steam explosion treatment and pressing conditions. If the pre- treatment temperatures were 160–180°C and the time 90min, the yield of furfural was 64.8–67.2% from that which was theoretically possible. The furfural obtaining dynamics significantly increases in the first 10minutes, when the yield of furfural at 180°C is almost twice as high as at 160°C. The obtained maximal MOE value (3250N mm-2) and good enough surface of some panels demonstrate that all prepared hemp shives materials can be used for binder-less panel production. The obtained excellent correlation between MOE and MOR values (r = 0.9) demonstrates that the strength of the composites could be predictable

Catalyzed Hydrothermal Pretreatment of Oat Husks for Integrated Production of Furfural and Lignocellulosic Residue

This study presents a novel approach for biorefining oat husks into furfural, leveraging a unique pilot-scale setup. Unlike conventional furfural manufacturing processes, which often result in substantial cellulose degradation and environmental concerns associated with sulfuric acid usage, our method utilizes phosphoric acid as a catalyst to achieve high furfural yield while minimizing cellulose destruction. Drawing on our research conducted in a distinctive pilot-scale environment, we successfully developed and implemented a tailored biorefining process for oat husks. Through meticulous experimentation, we attained a remarkable furfural yield of 11.84% from oven-dried mass, accompanied by a 2.64% yield of acetic acid. Importantly, our approach significantly mitigated cellulose degradation, preserving 88.31% of the cellulose content in oat husks. Existing catalytic (H2SO4) furfural manufacturing processes often lead to substantial cellulose degradation (40–50%) in lignocellulosic leftover during the pretreatment stage. As a result of the research, it was also possible to reduce the destruction of cellulose in the lignocellulose leftover to 11.69% of the output (initial) cellulose of oat husks. This research underscores the feasibility and sustainability of utilizing oat husks as a valuable feedstock for furfural production, highlighting the potential of phosphoric acid as a catalyst in biorefining processes. By showcasing our unique pilot-scale methodology, this study contributes to advancing the field of environmentally friendly biorefining technologies

Direct Furfural Production from Deciduous Wood Pentosans Using Different Phosphorus-Containing Catalysts in the Context of Biorefining

This study seeks to improve the effectiveness of the pretreatment stage when direct furfural production is integrated into the concept of a lignocellulosic biomass biorefinery. First of all, the catalytic effects of different phosphorus-containing salts (AlPO₄, Ca₃(PO₄)₂, FePO₄, H₃PO₄, NaH₂PO₄) were analysed in hydrolysis for their ability to convert birch wood C-5 carbohydrates into furfural. The hydrolysis process was performed with three different amounts of catalyst (2, 3 and 4 wt.%) at a constant temperature (175 °C) and treatment time (90 min). It was found that the highest amount of furfural (63–72%, calculated based on the theoretically possible yield (% t.p.y.)) was obtained when H₃PO₄ was used as a catalyst. The best furfural yield among the used phosphorus-containing salts was obtained with NaH₂PO₄: 40 ± 2%. The greatest impact on cellulose degradation during the hydrolysis process was observed using H₃PO₄ at 12–20% of the initial amount, while the lowest degradation was observed using NaH₂PO₄ as a catalyst. The yield of furfural was 60.5–62.7% t.p.y. when H₃PO₄ and NaH₂PO₄ were combined (1:2, 1:1, or 2:1 at a catalyst amount of 3 wt.%); however, the amount of cellulose that was degraded did not exceed 5.2–0.3% of the starting amount. Enzymatic hydrolysis showed that such pretreated biomass could be directly used as a substrate to produce glucose. The highest conversion ratio of cellulose into glucose (83.1%) was obtained at an enzyme load of 1000 and treatment time of 48 h

Influence of Biomass Pretreatment Process Time on Furfural Extraction from Birch Wood

Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, dilute sulphuric acid hydrolysis was used for hemicelluloses secession from birch wood. The reaction was investigated at different biomass treatment times (10-90 min, increasing it by 10 min). We found that the greatest amount of furfural 1.4-2.6%, which is 9.7-17.7% from theoretical possible yield, was formed in the first 30 min of the beginning of birch wood pentoses monosaccharide dehydration, but the greatest yield of furfural 10.3%, which is 70.0% from the theoretical yield, can be obtained after 90 min. Given that furfural yield generally does not exceed 50% from the theoretical amount, the result can be considered as very good

PROCESSING POSSIBILITIES OF BIRCH OUTER BARK INTO GREEN BIO-COMPOSITES

The main objective of the study was to obtain bio-composites from grey alder sawdust using a mixture of birch outer bark suberinic acids as a binder, and to test their mechanical properties. Ethanol-extracted birch outer bark was used as a raw material for the investigation. Characteristics (suberinic acids content, epoxy acids content and acid number) of the hydrolytically depolymerized birch outer bark binder were also determined. The initial filler/binder ratio and molding parameters (temperature and pressure) were established by the full factorial design. Preliminary data showed that the increase of the pressing temperature from 160 to 200 °C at a pressure of 3.5 MPa resulted in a minor growth of the boards’ density (up to 1.0 g/cm3) and bending strength (up to 17.1 MPa). Our investigation has shown that it is possible to use one of the plywood production residues – outer birch bark – as a raw material for obtaining particleboards, which have mechanical properties beyond the standard limits. The used method is also environmentally friendly, easy realizable in practice and has a potential to be cost-effective

Thermomechanical and Alkaline Peroxide Mechanical Pulping of Lignocellulose Residue Obtained from the 2-Furaldehyde Production Process

The necessity for the reduction in greenhouse gas emissions, the growing demand for the improvement of biorefinery technologies, and the development of new biorefining concepts oblige us as a society, and particularly us, as scientists, to develop novel biorefinery approaches. The purpose of this study is to thoroughly evaluate the leftover lignocellulosic (LC) biomass obtained after the manufacture of 2-furaldehyde, with the intention of further valorizing this resource. This study demonstrates that by using thermomechanical and alkaline peroxide mechanical pulping techniques, birch wood chips can be used in the new biorefinery processing chain for the production of 2-furaraldehyde, acetic acid, and cellulose pulp. In addition, the obtained lignocellulosic residue is also characterized. To produce a lignocellulosic material without pentoses and with the greatest amount of cellulose fiber preserved for future use, a novel bench-scale reactor technology is used. Studies were conducted utilizing orthophosphoric acid as a catalyst to deacetylate and dehydrate pentose monosaccharides found in birch wood, converting them to 2-furaldehyde and acetic acid. The results showed that, with the least amount of admixtures, the yields of the initial feedstock’s oven-dried mass (o.d.m.) of 2-furaldehyde, acetic acid, and lignocellulose residue ranged from 0.04 to 10.84%, 0.51 to 6.50%, and 68.13 to 98.07%, respectively, depending on the pretreatment conditions utilized. The ideal 2-furaldehyde production conditions with reference to the purity and usability of cellulose in residual lignocellulosic material were also discovered through experimental testing. The experiment that produced the best results in terms of 2-furaldehyde yield and purity of residual lignocellulose used a catalyst concentration of 70%, a catalyst quantity of 4%, a reaction temperature of 175 °C, and a treatment period of 60 min. It was possible to create pulp with a tensile index similar to standard printing paper by mechanically pulping the necessary LC residue with alkaline peroxide, proving that stepwise 2-furaldehyde production may be carried out with subsequent pulping to provide a variety of value-added goods

Characterization of Birch Wood Residue after 2-Furaldehyde Obtaining, for Further Integration in Biorefinery Processing

Latvia is a large manufacturer of plywood in Eastern Europe, with an annual production of 250,000 m3. In Latvia’s climatic conditions, birch (Betula pendula) is the main tree species that is mainly used for plywood production. A significant part of the processed wood makes up residues like veneer shorts, cores, and cut-offs (up to 30%), which have a high potential for value-added products. The aim of this research was to comprehensively characterize lignocellulosic (LC) biomass that was obtained after 2-furaldehyde production in terms of further valorization of this resource. The polymeric cellulose-enriched material can be used in the new biorefinery concept for the production of 2-furaldehyde, acetic acid, cellulose pulp, thermomechanical (TMP) and an alkaline peroxide mechanical (APMP) pulping process. In addition, we experimentally developed the best 2-furaldehyde production conditions to optimize the purity and usability of cellulose in the leftovers of the LC material. The best experimental results in terms of both 2-furaldehyde yield and the purity of residual lignocellulose were obtained if the catalyst concentration was 70%, the catalyst amount was 4 wt.%, the reaction temperature was 175 °C,and the treatment time was 60 min. After process optimization with DesignExpert11, we concluded that the best conditions for maximal glucose content (as cellulose fibers) was a catalyst concentration of 85%, a catalyst amount of 5 wt.%, a temperature of 164 °C, and a treatment time of 52 min

Impact of Birch Wood Prehydrolysis Conditions upon the Yield and Properties of Activated CarbonfFrom Lignocellulose

The xylan-rich outer layer of birch veneer blocks making plywood factory residue veneer shorts is an ideal raw material for production of furfural, acetic acid and activated carbon. The aim of our investigation was to find optimum prehydrolysis conditions, within the limits of technological parameters tested at present, and to secure high yield and quality of all intended products. It has been elucidated that a 2% catalyst (H2SO4) concentration at 167–177oC ensures high yield of furfural and the quality of lignocellulose is appropriate for processing into activated carbon. During prehydrolysis, the plasticity of lignocellulose is greatly improved, and it granulates perfectly. The activated carbon yield in comparable conditions is by 10–15% higher; the sorption activity of iodine is practically the same (907 and 953 mg I2/g, respectively) as in the case of the catalyst concentration 3% (o.d. wood basis) even not taking into account the 13% lower activated carbon yield at a 3% catalyst concentration. The superheated steam expenditure is lower, since partly it can be substituted by carbon dioxide