Panos Kouris

Research Project Emiel Hensen / Panos Kouris

Setting up the base for the first lignin biorefinery: From lignin to biofuels and chemicals

 

Background

A considerable issue associated with large-scale ethanol production from lignocellulosic biomass is the co-production of large amounts of lignin. Lignin is one of the main constituents in the cell walls of almost all dry plants and available in large quantities. Nowadays, lignin is burned as a low fuel to produce steam and electricity. To make the future processing of large quantities of second generation biomass into chemicals and fuels economically viable, it is necessary to develop efficient routes to convert lignin into transportation fuels and chemicals. Our group has already proven in lab scale that lignin can be converted into lignin crude oil (LCO) via a catalytic de-polymerization process, under supercritical ethanol using layered double hydroxides-derived mixed oxides catalyst (CuMgAlOx). This LCO has already been found to be a suitable low sulfur marine fuel “as is”, creating thus a quicker route to revenue. The next step is to scale up this process in a 4 liter batch reactor and define the process operating window for converting lignin into (partial) deoxygenated aromatics in high yield and minimizing the possible repolymerization reactions. Additionally, a conceptual process design for pilot activities is being conducted, with feasibility studies and final (batch/continuous) process design for a combined pilot scale lignin-to-LCO & LCO-to-chemicals biorefinery.

Possible topics

Scaling-up the lignin depolymerization

Depolymerization: Scale-up of current process from 1 gram to 20-50 gram lignin scale in existing 4 L autoclave.

Operating window: Analysis of product composition as a function of operating conditions, solvent and catalyst composition.

Investigating the depolymerization and repolymerization behaviors of lignin during reaction. A variety of approaches such as GC-MS, NMR (1H, 13C, 2D HSQC), GPC, elemental analysis (CHO) etc. will be applied to analyze the monomeric product and characterize the structural change of lignin.

Recycle: Investigate the reuse of ethanol, catalyst and unconverted lignin.

Catalyst synthesis and characterization

Focus on screening out the most active mixed-oxide catalyst, optimizing the catalyst composition and synthesis method, investigating the structure-sensitivity relations by characterization and activity test in depolymerization reactions.

 Process design and piloting

Functional and conceptual process design. Work with AspenPlus. Economic evaluation of the process.

Reactor engineering (mass transfer limitations & design options/issues linked with experimental part).

References

1.  X.Huang, T.I.Koranyi, M.D. Boot, and E.J.M. Hensen, ChemSusChem 2014, 7, 2276 – 2288.

2.  A.J. Ragauskas, G.T. Beckham, M.J. Biddy, R. Chandra, F. Chen, M.F. Davis,  B.H. Davison, R.A. Dixon, P. Gilna, M. Keller, et al. Science 2014, 344, 709.

For further information:

Emiel Hensen  (Helix, STW 3.35, Tel 5178, e.j.m.hensen@tue.nl)

Panos Kouris (Helix, STW 4.39, Tel 2287, p.d.kouris@tue.nl)