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

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

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

Chemical Composition and Mechanical Properties of Wood after Thermal Modification in Closed Process under Pressure in Nitrogen

In this study, silver birch (Betula pendula) and Scots pine (Pinus sylvestris) wood planks (1000 × 100 × 25 mm) were thermally modified in pilot-scale equipment. Research extended our knowledge of the thermal modification (TM) process in a closed system under nitrogen pressure, as well as how process parameters affect the chemical composition and mechanical strength of wood. Various TM regimes were selected—maximum temperature (150–180 °C), modification time (30–180 min), and initial nitrogen pressure (3–6 bar). Chemical analyses were performed to assess the amount of extractives, lignin, polysaccharides and acetyl group content following the TM process. The mechanical properties of TM wood were characterized using the modulus of rupture (MOR), modulus of elasticity (MOE), and Brinell hardness. The MOR of both studied wood species following TM in nitrogen was reduced, but MOE changes were insignificant. The Brinell hardness of TM birch wood’s tangential surface was much higher than that of the radial surface, although Scots pine wood showed the opposite pattern. TM birch and pine wood specimens with the highest mass loss, acetone soluble extractive amount, and the lowest xylan and acetyl group content had the lowest MOR and Brinell hardness

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

The Effect of Catalyst Amount on the Production of Furfural and Acetic Acid from Birch Wood in the Biomass Pretreatment Process

The conversion of lignocellulosic biomass to bioethanol has attracted renewed attention in recent years due to its environmental, economic, and strategic advantages. Birch woodchips were used as the raw material due its several characteristics, such as high cellulose and hemicellulose content that can be readily hydrolyzed into fermentable sugars. Dilute acid hydrolysis was used as the pretreatment process which can be considered as one of the most promising biomass pretreatment methods. But there occur several challenges and limitations in the process of converting birch wood to bioethanol. During the biomass pretreatment process the degradation products such as furfural and acetic acid, which has an inhibitory effect on the further fermentation process in the bioethanol production section, may be form from hemicelluloses. But both these inhibitors as individual chemicals are very important for the production of many products. In order to develop the theoretical foundations for joint production technology of furfural, acetic acid and bioethanol, it is necessary to study the effect of the amount of catalyst on the formation of furfural and acetic acid from birch woodchips and the content of cellulose in the lignocellulose residue after pretreatment process. The effect of the amount of the catalyst on the furfural and acetic acid formation process was studied in a range from 1.5% to 4.0%, calculated on oven dried wood (o.d.w.), while temperature and time of the pretreatment process were constant. The obtained results demonstrated that the effect of the amount of the catalyst on the formation of furfural and acetic acid and the content of cellulose in the lignocellulosic leftover is very significant. The amount of furfural increased from 6.2 % to 10.8%, calculated on o.d.w., the amount of acetic acid increased from 5.2% to 5.8%, calculated on o.d.w., but the content of cellulose in the lignocellulosic leftover decreased from 34.7% to 14.1%, calculated on o.d.w. after 90 min from the beginning of the birch wood pretreatment process

Etiķskābes iegūšana no bērza koka koksnes pie tās kompleksas pārstrādes

Tehnisko etiķskābi pasaulē ražo 165 kompānijas 8,2 milj. t gadā praktiski tikai no naftas produktiem. Prognozē, ka tās ražošanas apjoms līdz 2015. gadam palielināsies līdz 11,8 milj. t gadā un to papildus daudzumu vajadzēs ražot, galvenokārt, no biomasas. Pēc Valsts meža dienesta Meža departamenta datiem bērza koksne resursi Latvijā sastāda vairāk nekā 150 milj. m3. Pēc kopējās krājas bērzs aizņem otro vietu starp valdošajām koku sugām Latvijā. Tāpēc ir ļoti svarīgi atrast šiem resursiem ekonomiski izdevīgu izmantošanu. Šīs problēmas efektīvākais risinājums varētu būt kompleksa bērza koksne pārstrāde ražojot etiķskābi un citus produktus. Pārstrādājot tikai 1 milj. m3 šīs koksnes atliekas varētu saražot 25 000 t etiķskābes. Tas dos iespēju ekoloģiski tīri un ekonomiski efektīvi pārstrādāt bērza koksnes atliekas. Lai atrisinātu šo problēmu, pirmo reizi pasaules zinātniskajā praksē, izmantojot jaunā patentā [1, 2] aprakstītās idejas, izpētīta bērza koksnes hemiceluložu polisaharīdu deacetilēšanās un etiķskābes veidošanās procesa galvenās likumsakarības. Parādīts, ka etiķskābes veidošanās dinamiku un iznākumu ietekmē galvenokārt procesa temperatūra, katalizatora koncentrācija un procesa ilgums. Iegūtie rezultāti būs par pamatu jaunai etiķskābes iegūšanas no bērza koka koksnes tehnoloģijai, par kuras rūpniecisko realizēšanu jau interesējas SIA „LFK” un citas firmas Latvijā

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