Polar and non-polar components in Fast Pyrolysis Bio-Oil in relation to REACH registration.

Sep 2021
Publications

Fast pyrolysis is maturing, and significant amounts of pyrolysis oil are introduced on the European market. Consequently, registration in the European REACH system is required, demanding dedicated chemical analyses and expertise. Both VTT and BTG are already active in the fast pyrolysis field for a long time, and in several projects, attention was given to REACH related issues. Therefore, it was decided to have a dedicated effort within IEA Bioenergy Task 34 to combine and share the experiences of VTT and BTG on this subject which is expected to be beneficial for producers, end-users, project developers and researchers in this field.

Summary

Fast pyrolysis bio-oil (FPBO) is entering the European market and estimated production capacity will exceed 100 million litres in 2021 with individual production capacities of well above 10 kton/year.

So-called REACH registration is mandatory. REACH stands for Registration, Evaluation, Authorisation and Restriction of Chemicals. It is the European system aiming to protect human health and the environment through the better and earlier identification of the intrinsic properties of chemical substances. In 2013 a FPBO registration dossier was submitted to ECHA (European Chemicals Agency). In the dossier FPBO is classified as a UVCB, i.e. a product with Unknown or Variable composition, Complex reaction products or Biological materials. The registration is valid for FPBO produced by fast pyrolysis from lignocellulosic biomass and is characterized by its chemical and physical properties. In addition, specific restrictions are given on the concentrations of some polar and non-polar compounds. This report focuses on the analyses of these compounds.

The polar compounds considered are formaldehyde, acetaldehyde, methanol, furfural, phenol and cresol. Different analysis methods have been applied by VTT, University of Groningen (RUG) and BTG to measure the concentrations of these compounds in FPBOs of different origin or post-treated in different ways. Taking into account the complexity of measuring individual components in FPBO the agreement between the measuring methods is acceptable. Formaldehyde cannot be measured directly as it is in chemical equilibrium with methylene glycol. The actual concentration is calculated using the equilibrium constant and the sum of concentration of formaldehyde and methylene glycol. Additionally, the formaldehyde concentration in the atmosphere around fast pyrolysis units was measured. Under normal working conditions and proper pre-cautions, the formaldehyde concentration is always well below legal exposure limits.

The specific non-polar compounds in FPBO refer to the poly-aromatic hydrocarbons (PAHs) and more in particular the EPA PAH13. The starting point were the different analysis methods known from literature for measuring PAHs in FPBO. RUG & BTG have evaluated these methods and further improved them. A specific challenge is to avoid the co-extraction of phenolic compounds as it gives overlapping peaks in the subsequent analysis resulting in false PAH values. Some variation in results is observed, but in all cases the total PAH13 content is well below the limit of 35 ppm as given in the Reach registration for FPBO.

Summarizing, the analysis methods have successfully been developed or improved. Based on analysis of FPBOs from different biomass resources it appears that generally FPBOs can comply with the specifications and limits given in the FPBO REACH dossier.

Full report available here: IEA-REACH-related-compounds-in-FPBO-final2