Production of pyrolytic lignin for the phenolic resin synthesis via fast pyrolysis

Recycling of waste wood into resol type phenol-formaldehyde (PF) resins via fast pyrolysis was demonstrated. Waste wood collected from the building demolition site in Finland was pyrolyzed with 20 kg/h circulating fluidized bed pyrolysis pilot unit. Pilot was operated with high organic liquid yield (60 wt% on average) and the produced fast pyrolysis bio-oil was fractionated by water addition into aqueous phase and water insoluble phase. The obtained fractions were characterized, and the water-insoluble viscous lignin fraction was used in the synthesis of PF-resins. Commercial phenol was successfully replaced by pyrolytic lignin fraction at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% producing resins of low in free formaldehyde content, but resins with high replacement ratio exhibited higher viscosities. The use of H2O/n-butanol mixture as solvent at a ratio 70:30 wt/wt% proved capable to prolong the storage time of the resin and helped to maintain the viscosity at acceptable values for at least 2 weeks before their use in the targeted application. Finally, the gluing performance of the resins was evaluated by measuring the tensile shear strength of lap joints formed by gluing 5 mm thick beech wood veneers. All the produced resins fulfilled a dry strength limit of ≥ 10 N/mm2. Wet strength limit ≥ 7 N/mm2 was fulfilled by the resins with the replacement ratio up 40 wt%, but resins with replacement ratio of 50 wt% had somewhat reduced wet strength. These results confirm a promising protentional application of pyrolysis derived lignin fraction in phenolic wood adhesives, at least in dry conditions

Valorization of Eucalyptus, Giant Reed Arundo, Fiber Sorghum, and Sugarcane Bagasse via Fast Pyrolysis and Subsequent Bio-Oil Gasification

[Image: see text] Fast pyrolysis of giant reed Arundo (Arundo donax), fiber sorghum (Sorghum bicolor L.Moench), eucalyptus (Eucalyptus spp.), and sugarcane bagasse (Saccharum officinarum) was studied in bench-scale bubbling fluidized bed reactor. Product yields were determined, and detailed physicochemical characterization for produced fast pyrolysis bio-oils (FPBOs) was carried out. The highest organic liquid yield (dry basis) was observed with sugarcane bagasse (59–62 wt %), followed by eucalyptus (49–53 wt %), giant reed Arundo (39 wt %), and fiber sorghum (34–42 wt %). After the pyrolysis experiments, produced FPBOs were gasified in an oxygen-blown autothermal catalytic reforming system for the produced synthesis gas. The gasifier consists of a partial oxidation zone where the FPBO is gasified, and the raw syngas is then reformed over a fixed bed steam-reforming catalyst in the reforming zone. The gas production (∼1.7 Nm(3)/kg FPBO) and composition (H(2) ∼ 50 vol %, CO 20–25 vol %, and CO(2) 25–30 vol %) were similar for all FPBOs tested. These results show that the combination of fast pyrolysis with subsequent gasification provides a technically feasible and feedstock flexible solution for the production of synthesis gas

Entrained Flow Gasification of Polypropylene Pyrolysis Oil

Petrochemical products could be produced from circular feedstock, such as waste plastics. Most plants that utilize syngas in their production are today equipped with entrained flow gasifiers, as this type of gasifier generates the highest syngas quality. However, feeding of circular feedstocks to an entrained flow gasifier can be problematic. Therefore, in this work, a two-step process was studied, in which polypropylene was pre-treated by pyrolysis to produce a liquid intermediate that was easily fed to the gasifier. The products from both pyrolysis and gasification were thoroughly characterized. Moreover, the product yields from the individual steps, as well as from the entire process chain, are reported. It was estimated that the yields of CO and H(2) from the two-step process were at least 0.95 and 0.06 kg per kg of polypropylene, respectively, assuming that the pyrolysis liquid and wax can be combined as feedstock to an entrained flow gasifier. On an energy basis, the energy content of CO and H(2) in the produced syngas corresponded to approximately 40% of the energy content of the polypropylene raw material. This is, however, expected to be significantly improved on a larger scale where losses are proportionally smaller

Evaluation of Analysis Methods for Formaldehyde, Acetaldehyde, and Furfural from Fast Pyrolysis Bio-oil

Fast pyrolysis bio-oil (FPBO), a second-generation liquid bioenergy carrier, is currently entering the market. FPBO is produced from biomass through the fast pyrolysis process and contains a large number of constituents, of which a significant part is still unknown. Various analytical methods have been systematically developed and validated for FPBO in the past; however, reliable methods for characterization of acetaldehyde, formaldehyde, and furfural are still lacking. In this work, different analysis methods with (HS-GC/ECD, HPLC, UV/Vis) and without derivatization (GC/MSD, HPLC) for the characterization of these components were evaluated. Five FPBO samples were used, covering a range of biomass materials (pine wood, miscanthus, and bark), storage conditions (freezer and room temperature), and after treatments (none, filtration, and vacuum evaporation). There was no difference among the methods for the acetaldehyde analysis. A significant difference among the methods for the determination of formaldehyde and furfural was observed. Thus, more data on the accuracy of the methods are required. The precision of all methods was below 10% with the exception of the HPLC analysis of acetaldehyde with an RSD of 14%. The concentration of acetaldehyde in the FPBO produced from the three different biomasses and stored in a freezer after production ranged from 0.24 to 0.60 wt %. Storage at room temperature and vacuum evaporation both decreased significantly the acetaldehyde concentration. Furfural concentrations ranged from 0.11 to 0.36 wt % for the five samples. Storage and after treatment affected the furfural concentration but to a lesser extent than for acetaldehyde. Storage at room temperature decreased formaldehyde similarly to acetaldehyde; however, after vacuum-evaporation the concentration of formaldehyde did not change. Thus, the analysis results indicated that in FPBO the equilibrium of formaldehyde and methylene glycol is almost completely on the methylene glycol side, as in aqueous solutions. All three methods employed here actually measure the sum of free formaldehyde and methylene glycol (FAMG)

Synthesis and Characterization of Novel Catalytic Materials Using Industrial Slag: Influence of Alkaline Pretreatment, Synthesis Time and Temperature

Industrial ferrous wastes found their application in construction. However, they are mostly stored polluting the environment. In the current work, possibility of value added products synthesis from steel slag with their further use as catalysts was investigated. Slag-based catalysts were obtained by alkaline treatment with sodium hydroxide by variation of synthesis parameters. The physico-chemical properties of the synthesized materials were determined by N2-physisorption, SEM, EDX, TEM, XRD and TPD. Slag-based catalysts were applied in the transformation of wood biomass, namely softwood sawdust. Novel catalytic materials synthesized from industrial slag exhibited the presence of strong basic sites and highly crystalline phases of SiO2, Al2O3, CaCO3, Ca(OH)2, Fe2O3, MgO and TiO2. Alkaline treatment of the raw material promoted creation of mesoporosity and an increase of the surface area. Catalytic fast pyrolysis of pine sawdust displayed variations in the yields of the reaction products in the presence of catalysts as compared to thermal fast pyrolysis.</p

Activated Carbons from Fast Pyrolysis Biochar as Novel Catalysts for the Post-Treatment of Pyrolysis Vapors, Studied by Analytical Pyrolysis

Biochars are attractive materials for carbon catalysts since their carbon content and surface area are relatively high and minerals present in biochar can act as active sites for catalytic reactions. In this study, biochars from the fast pyrolysis of birch, pine, and unbarked willow were activated and acid washed. These materials were tested as catalysts for a post-treatment of pine wood pyrolysis vapors, aiming at stabilizing the vapors before their condensation. All the unmodified biochars had high content of minerals, those being highest in willow due to the bark. After the activation treatments, the surface areas and pore volumes of all biochars significantly increased. All studied biochars and activated carbon catalysts reduced the oxygen content of the pyrolysis degradation products. This effect was more pronounced for compounds derived from polysaccharides vs. lignin. The most promising catalyst for vapor upgrading was unwashed activated carbon from willow, having high surface areas and pore volumes together with high mineral contents. These properties together promoted the high conversion of polysaccharide-derived products (anhydrosugars, acids, and pyrans) into CO2. Release of highly oxidized degradation products may indicate that reductive stabilization takes place via hydrogen migration from the polysaccharide-derivatives to lignin derivatives, mediated by the carbon catalyst

Lignoselluloosan komponenttien luonnehtiminen analyyttisellä pyrolyysi-kaasukromatografia- massaspektrometrialla

Analytical pyrolysis combined with gas chromatography mass spectrometry (Py-GC/MS) is a technique that can be used for the analysis of lignocellulose materials in situ. Pyrolysis degradation products provide information concerning the nature and origin of the initial sample. The main aim of this thesis was to apply analytical pyrolysis for lignin and carbohydrate characterisation from various lignocellulosic plant materials. Isothermal pyrolysis was the main technique utilised. In addition, thermochemolysis, thermal desorption and fractionated pyrolysis were applied in order to provide better understanding of the changes observed in lignin structure and carbohydrate composition in various materials and processes. In pyrolysis, hardwood lignin is degraded to guaiacyl and syringyl type pyrolysis degradation products with similar side chain structures, whereas carbohydrates form stable anhydrosugars. Lignin degradation products can be used to define the lignin composition and S/G ratio of the wood feedstocks. However, Py-GC/MS cannot be recommended for the comparison of carbohydrate composition between different wood species. Information on lignin structure and quantity was obtained directly from pulps by Py-GC/MS. Decrease of oxygenated lignin pyrolysis products and increase of short side chain structures were associated with beta-ether bond cleavage. Decrease of the short side chain structures as a function of delignification was interpreted to indicate leaching of the lignin products formed in cooking, and thus enrichment of native lignin in the residual pulp lignin. Due to the more complex chemical structure of brewers spent grain than of wood, its lignin composition was characterised by Py-GC/MS and thermochemolysis. Thermochemolysis results demonstrated that Py-GC/MS leads to underestimation of native type syringyl structures and S/G ratios. In addition, thermochemolysis with TMAAc and TMAH reagents was applied as a means to differentiate between free fatty acids and esters, respectively. The results showed that thermochemolysis with alkaline TMAH can be used to determine total fatty acid contents from the aliphatic and aromatic esters. TMAAc can be used to distinguish between free acids and aliphatic esters, but not between aromatic esters and free acids. In addition a thermal desorption method was developed to provide information on the odorous volatile organic compounds released from lignin. The method is applicable to the comparison of different lignin samples below their thermal degradation temperatures.Pyrolyysi-kaasukromatografia-massaspektrometrialla (Py-GC/MS) voidaan analysoida lignoselluloosamateriaaleja ilman tarvetta eristää niiden komponentteja. Pyrolyysituotteet antavat tietoa tutkittavan näytteen luonteesta ja alkuperästä. Tässä väitöskirjassa tutkittiin laajasti analyyttisen pyrolyysin soveltuvuutta ligniinin ja hiilihydraattien karakterisointiin erilaisista lignoselluloosamateriaaleista. Pääasiallisena menetelmänä käytettiin isotermistä pyrolyysiä. Sen lisäksi hyödynnettiin termokemolyysi-, termodesorptio- ja fraktiopyrolyysitekniikoita, jotta voitiin paremmin ymmärtää muutoksia ligniinin rakenteessa ja hiilihydraattien koostumuksessa eri materiaaleissa ja prosesseissa. Pyrolyysissä hiilihydraatit muodostavat stabiileja anhydrosokereita, kun taas lehtipuun ligniini hajoaa sivuketjurakenteeltaan analogisiksi guajasyyli- ja syringyylityyppisiksi yhdisteiksi. Näiden pyrolyysituotteiden avulla voidaan lignoselluloosaraaka-aineista määrittää ligniinin koostumus ja syringyyli-guajasyylisuhde (S/G). Työssä saatujen tulosten perusteella Py-GC/MS-tekniikkaa ei kuitenkaan voida suositella hiilihydraattikoostumuksen vertaamiseen eri puulajien välillä. Kemiallisten massojen Py-GC/MS antoi tietoa ligniinin pitoisuudesta ja rakenteesta ilman edeltävää ligniinin eristystä. Työssä havaittiin, että happea sisältävien ligniinin pyrolyysin hajoamistuotteiden väheneminen ja lyhyen sivuketjun omaavien rakenteiden lisääntyminen ovat yhteydessä keiton aikana tapahtuneeseen beta-eetterisidosten katkeamiseen. Vastaavasti lyhyen sivuketjun omaavien pyrolyysituotteiden väheneminen massaa valkaistaessa osoitti keittoprosessissa syntyneiden kemiallisten rakenteiden poistuvan ja natiivin kaltaisen ligniinin rikastuvan massan jäännösligniiniin. Koska panimomäskillä on monimutkaisempi kemiallinen koostumus kuin puulla, sen ligniinin rakennetta luonnehdittiin sekä Py-GC/MS- että termokemolyysitekniikoilla. Termokemolyysin antamat tulokset osoittivat, että Py-GC/MS aliarvioi luonnollisten syringyylirakenteiden osuuden ja S/G-suhteen. Termokemolyysiä sovellettiin myös erottamaan vapaat rasvahapot niiden estereistä käyttämällä TMAAc- ja TMAH-reagensseja. Tulokset osoittivat, että alkalista TMAH-reagenssia voidaan käyttää kokonaisrasvahappopitoisuuden määrittämiseen sekä alifaattisista että aromaattisista estereistä. TMAAc-reagenssia voidaan puolestaan käyttää erottamaan vapaat hapot ja alifaattiset esterit, mutta ei aromaattisia estereitä ja vapaita happoja. Lisäksi kehitettiin termodesorptioon perustuva menetelmä ligniinistä haihtuvien haisevien orgaanisten yhdisteiden määrittämiseksi. Menetelmä soveltuu erilaisten ligniininäytteiden vertailuun lämpötiloissa, jotka ovat alle niiden termisen hajoamislämpötilan