Title:
Hydrothermal Lignin Liquefaction
Author(s):
Hornung, U., Forchheim, D., Meyer, P., Kruse, A.
Document(s):
Paper
Abstract:
A high pressure hydrothermal process is applied to convert lignin to phenol. The advantage of such an approach is that fast hydrolysis reactions, thermal degradation reactions and in situ hydrogenation via the water gas shift reaction are taking place simultaneously. 32 g of lignin and 400 ml of water are processed in a 1 l tumbling batch reactor at 380 °C and 24 MPa with reaction times between 30 min and 4 h. Since the formation of solid residues is not fully understood the gained solids are analyzed with FT-IR to characterize the chemical nature. The dominant structure is aliphatic with a low content of hydroxy/methoxy groups, and presumably a low amount of fully substituted aromatic compounds. In order to influence the solid formation different gas atmospheres as CO, H2, CO2, N2 were applied during the hydrothermal treatment of lignin. The idea is to suppress the formation of solids residues due to in situ hydrogenation reactions via the water gas shift reaction or via direct hydrogen addition. This expectation could not be verified, since the yields of solids are higher in presence of CO, formic acid and hydrogen, but in matters of phenol concentration a slight increase is achieved with hydrogen and formic acid addition. FT-IR analysis shows that the chemical nature of the solids is more or less independent on the applied reaction times and gas atmospheres.
Keywords:
lignin, phenol, hydrothermal liquefaction, subcritical water conversion, FTIR of solid residues
Topic:
Biomass Resources
Subtopic:
Biomass residues and by-products
Event:
19th European Biomass Conference and Exhibition
Session:
VP1.2.39
Pages:
510 - 513
ISBN-13:
978-88-89407-55-4
ISBN-10:
88-89407-55-7
Paper DOI:
10.5071/19thEUBCE2011-VP1.2.39
Price:
FREE
