THERMAL-CHEMICAL FRACTIONATION OF LIGNOCELLULOSIC BIOMASS H. Heeres, E.J. Leijenhorst, R. Ongena, L. Van de Beld BTG Biomass Technology Group BV PO BOX 835, 7500AV Enschede, the Netherlands E-mail: Heeres@btgworld.com ABSTRACT: Biomass is a valuable, sustainable feedstock for the production of chemicals and materials, and will play an important role in the transition towards a Sustainable Process Industry. Bio-based products – products wholly or partly derived from materials of biological origin – can make the society more sustainable and lower its dependence on fossil fuels. For the optimal utilization of bio-resources, fractionation on the basis of functionalities is often desired. Most commonly, biomass is separated into its main constituents lignin, cellulose and hemi-cellulose by steam or acid treatment. Thermo- chemical fractionation is an alternative, innovative two-step conversion process to transform different bio-resources into raw- materials for renewable chemicals and products. In this approach, a short thermal treatment at elevated temperature (fast pyrolysis) is followed by a low temperature fractionation of the mineral free, liquid product (FPBO) that keeps the key chemical functionalities intact in separate, liquid, depolymerized fractions. These fractions consist of components derived from the de-polymerization of cellulose, hemicellulose and lignin. Both the fractionation of FPBO and the use of the fractions in bio-based products are further developed in the EU-funded project called Bio4Products and Interreg project “Groen Goud”. The application of the pyrolytic fractions will be demonstrated in a number of end products such as phenolic resins, sand foundry moulding resins, paints, engineered wood and natural fibre reinforced products. Exploratory research on both the fractionation and the applications has been carried out at bench-scale using pyrolysis oil derived from different types of biomass. Results were very positive and larger quantities of pyrolytic fractions are required for further product development and demonstration. Recently, a dedicated fractionation unit with a throughput capacity of 3 ton FPBO/day has been designed, constructed and commissioned. Keywords: Fast Pyrolysis, fractionation, demonstration, biomass, pilot plant, TCF, thermochemical 1 INTRODUCTION Pyrolysis is the thermal decomposition of organic material in an oxygen-free environment, and it results in solid, liquid and gaseous products. Fast pyrolysis is applied when the aim is to maximize the liquid yield. In this context fast relates to the rapid heating of the organic material. Typically, the process is carried out at ambient pressures and a reactor temperatures of around 500°C. The biomass is rapidly heated and the vapour stream is rapidly cooled to avoid further reactions, and to maximize the yield of liquids. In case of clean woody biomass (e.g. pine wood) the liquid yield can be up to 70 wt%; about 15 wt% of the biomass is converted into charcoal and the remaining 15 wt% to non-condensable gases (e.g. CO, CO2, CH4). The liquid product is often called Fast Pyrolysis Bio- Oil (FPBO), although its properties do not justify to call it an oil. It is polar, acidic, contains water, and it is inmiscible with fossil oils. It can be seen as a very broad mixture of components derived from the deploymerisation of cellulose, hemicelluloses, and lignin components of the feedstock. Nowadays, clean wood-based FPBO is commercially used to replace fossil heavy fuel oils and natural gas in boiler applications. In Europe, commercial sized fast pyrolysis plants (> 10 MWth) are operational in Joensuu, Finland (Fortum), and in Hengelo (Empyro), the Netherlands [1]. Recently, the realisation of a new plant was announced by GreenFuelNordic (Lieska, Finland), which is more or less identical to the Empyro plant. The Empyro plant is based on the BTG fast pyrolysis process, and –by the end of 2018- Empyro has produced over 30 million litres of FPBO. Empyro is a polygeneration plant and an overall energetic efficiency of over 85% is achieved (pyrolysis oil, process steam & electricity). Nearly all the oil produced is supplied to a dairy company and used as a co-feed in a process steam boiler combined with natural gas. The FPBO complies with the European standard for FPBO fuel for use in industrial boilers (EN 16900:2017). The very short heating time in the fast pyrolysis process results in a liquid product containing fragments of the original biomass. This means that the original chemical functionalities present in the biomass are largely retained. In the fractionation process the FPBO is separated into different fractions with specific functionalities like extractives, carbohydrates/sugars and lignin/phenolics, see Fig. 1. Each fraction can be used as renewable raw material for a wide variety of end products. Fig. 1: Illustration of the 2-step Thermo-Chemical Fractionation (TCF) process. Alternatively, the approach of staged or fractional condensation is often proposed in literature [2,3]. The production of the various fractions is an integral part of the process by operating a number of condensers at different temperatures. A separation of components on the basis of boiling point/vapor pressure will be obtained. This is principally different from the TCF process in which a separation on the basis of solubility in specific solvents is achieved, and a better separation on functionalities can be expected.