You are working on the “Organosolv fractionation of lignocellulosic biomass” and are at the beginning of the FLEXI-GREEN FUELS process. Could you describe in simple words the organosolv process?

Organosolv is a process in which lignocellulosic or plant biomass is treated in mixture of water with an organic solvent, typically we use ethanol at temperature normally ranging between 160 °C and 200 °C for a typical period between 15 min and 60 min, that eventually results in fractionating biomass into its major components, which are cellulose, hemicellulose and lignin. This way, we can then process those streams separately and use them in the most efficient way as feedstocks for the production of a range of green energy, chemicals and materials.

This work package requires a broad knowledge on the fractionation process, so let me ask you: “When did you start working on the organosolv pretreatment process?”

Our group has been working since long time with organosolv fractionation of lignocellulosic biomass. We actually started in 2014 to develop organosolv fractionation processes. Initially we started working with an already existing reactor, whereas at the same time we designed and implemented a custom hybrid organosolv-steam explosion reactor. We have invested a lot on the organosolv fractionation process. Both, in developing the process itself and understanding its fundamentals, but also by designing a custom reactor that is capable of performing organosolv in a continuous operation, which is a significant breakthrough in the field.

What additional benefits do you expect from the project?

Apart from starting new collaborations and especially in the field of using the fractions of cellulose, hemicellulose and lignin in interesting applications, an additional benefit was that within the project we work together with KIRAM in the recovery of the solvent that we use in the organosolv. That is very important for the process, as recovery and recycling of the used solvent (such as ethanol) is necessary towards establishing an economically viable process. Moreover, within the project we also work with the use of other solvents (than ethanol) and also tested the applications of triple solvent systems, as well as organic solvents that we have not worked in the past. This resulted to a fundamental understanding on how the solvents interact with biomass components and how we can tune them towards delivering fractions of desired qualities.

What is the most surprising result in these two years of the project?

By adjusting the composition of a multi-solvent system in organosolv, we generated fractions of qualities that we did not anticipate. That opened-up a lot of interesting work in understanding the fundamentals of the process.

Thank you for the insights into your thoughts. One last question. What is your favourite technical “research tool” and why?

Our favourite technical research tools is NMR and stands for Nuclear Magnetic Resonance. It allows us to analyse the molecular structure of our compounds. This method gives us the opportunity to have a very good view of the chemical structure of complex molecules such as lignin. This in turn allows us to understand how we can use this molecule and which are the best suited applications based on the specific structure it has. But also how we can affect the structure of the molecule by adjusting the process parameters of organosolv so as to deliver, for example, lignin of certain structure when aiming towards a specific application.