Process concepts are being explored to convert lignocellulosic biomass to bio-oil, which can subsequently be upgrade to liquid transportation fuels, e.g. by co-processing in a conventional oil refinery. The conversion processes are based on liquefaction in a high-boiling solvent at moderate temperatures and pressures, for instance 300°C and 40-60 bars.
One process concept uses the recycled bio-oil product as a liquefaction medium . Recycled bio-oil appeared indeed to be very effective in liquefying the biomass to high degree. However, it becomes increasingly heavy and viscous upon recycling. Hence, a line of investigation is focusing on reducing or mitigating the formation of heavy product. This is attempted either by avoiding their formation e.g. through optimization of process parameters or the use of acid-base additives [2,3] or by removing the heavy ends prior to recycle e.g. using a novel L/L extraction with T-swing [5,6].
Alternatively, we also explored the possibility to avoid recycling the bio-oil with its heavy ends. Here, we explored the use of cheap hydrocarbon solvents that are present in oil refineries. One approach proposes a once-through by liquefying the lignocellulose in a typical FCC feed and feeding the resulting blend directly to the FCC unit . Another approach exploits the natural L/L demixing of bio-oil and hydrocarbons a room temperature to recover and recycle the hydrocarbon solvent .
Beyond developing process concepts, we also try to better understand the chemistry of lignocellulose liquefaction. To this end, we undertook a detailed analysis of the bio-oil and recognized that it’s largely composed of phenolic components, without the water and sugar-like species found in pyrolysis oil . We also studied the liquefaction of the various constituents of lignocellulose and found the carbohydrates to be responsible for the undesired formation of char. In contrast, the lignin was responsible for the formation of heavy liquid products . Finally, we also investigated the role of the solvent in more depth in attempt to understand the properties what differentiate a good solvent from a poor one .
- M. Castellví Barnés, M.M. de Visser, J.-P. Lange, G. van Rossum and S.R.A. Kersten:Chemistry of the liquefaction of wood and its model components,2016, in preparation
- S. Kumar, A. Segins, J.-P. Lange, G. Van Rossum and S.R.A. Kersten:Liquefaction of lignocellulosic in light cycle oil: A process concept study,2015, ChemSusChem, 4 (6), p.p. 3087-3094. (DOI: 10.1021/acssuschemeng.6b00055
- S. Kumar, J.P. Lange, G. van Rossum and S.R.A. Kersten:Liquefaction of lignocellulose: Do basic and acidic additives help out?,
- 2015, Chem. Eng. J., 278, p.p. 99-104. (DOI: 10.1016/j.cej.2014.12.026)
- M. Castellví Barnés, J.-P. Lange, G. van Rossum and S.R.A. Kersten:A new approach for bio-oil characterization based on gel permeation chromatography preparative fractionation,2015, J. Anal. Appl. Pyrol., 113, p.p. 444-453. (DOI: 10.1016/j.jaap.2015.03.005)
- S. Kumar, J.-P. Lange, G. Van Rossum and S.R.A. Kersten:Bio-oil fractionation by temperature-swing extraction: Principle and application,2015, Biomass and Bioenergy, 83, p.p. 96-104. (DOI: 10.1016/j.biombioe.2015.09.003)
- S. Kumar, J.-P. Lange, G. Van Rossum and S.R.A. Kersten:Liquefaction of lignocellulose in fractionated light bio-oil: Proof of concept and techno-economic assessment,2015, ACS Sust. Chem. & Eng., 3 (9), p.p. 2271-2280. (DOI: 10.1021/acssuschemeng.5b00547)
- S. Kumar, J.-P. Lange, G. Van Rossum and S.R.A. Kersten:Liquefaction of Lignocellulose in Fluid Catalytic Cracker Feed: A Process Concept Study,2015, ChemSusChem, 8 (23), p.p. 4086-4094. (DOI: 10.1002/cssc.201500457)
- S. Kumar, J.P. Lange, G. van Rossum and S.R.A. Kersten:Liquefaction of Lignocellulose: process parameter study to minimize heavy ends,2014, Ind. Eng. Chem. Res., 53 (29), p.p. 11668-11676. (DOI: 10.1021/ie501579v)
- G. van Rossum, W. Zhao, M. Castellvi Barnes, J.-P. Lange, S.R. A. Kersten:Liquefaction of lignocellulosic biomass: solvent, process parameter, and recycle oil screening,2014, ChemSusChem, 7 (1), p.p. 253-259. (DOI: 10.1002/cssc.201300297)