[TC2015] applicability of medium boiling fraction of flash pyrolysis condensates in phenolic resins

Abstract

Fossil-based phenol is used to a large extend to produce phenol–formaldehyde (PF) resins, which are most commonly applied in engineered wood products such as plywood. Pyrolysis oil from straw pyrolysis might be a suitable bio-based substitute for such applications. By staged condensation of flash pyrolysis vapors, a phenolic monomers concentrated fraction could be produced. This fraction was used for the production of several PF resins with different recipes and degrees of substitution. Resulting resins were analyzed for free formaldehyde and dynamic viscosity as well as being characterized by curing behavior within a differential scanning calorimetry experiment. Finally, tensile strength specimen samples were made for testing according DIN EN 205. Bioresin tensile strength was found to lay in the range of 7–8 N/mm2, which is below but close to the minimum value of 10 N/mm2 for wood adhesive application

Valorization of aqueous waste streams from thermochemical biorefineries

“…25 Separation strategies for mixed phenolics have included adsorbents for phenolic-sugar separation, fractional condensation for a phenol-formaldehyde resin precursor, and combined solvent and staged pH extraction of methoxyphenols. [53][54][55] Reports of isolating monomers above 90 wt% purity from thermochemical streams are less prevalent, but one example leveraged steam distillation and multi-solvent extraction scheme to isolate syringol at 92.3%. 56 By extracting oxygenated aromatics, known for their toxicity to wastewater treatment microorganisms, 57,58 the necessity and/or severity of wastewater treatment can be minimized.…”