Hydrothermal Liquefaction of Glycyrrhiza Glabra L. (Liquorice): Effects of Catalyst on Variety Compounds and Chromatographic Characterization

Abstract

In this study, Glycyrrhiza glabra L. was transformed into liquid and solid products with catalysts (H3BO3, ZnO) and without catalyst at 250 degrees C, 300 degrees C, and 350 degrees C by using the hydrothermal liquefaction method. The obtained products were analyzed by the GC-MS, FT-IR, SEM, elemental analysis and(1)H NMR methods. The highest conversion rate was obtained as 35.73% (wt) using H(3)BO(3)as a catalyst at 350 degrees C. According to the results of the elemental analysis, the energy values of liquid products (light bio-oil, heavy bio-oil) ranged between 21.87 and 31.78 MJ kg(-1)and the energy values of solid products ranged between 16.22 and 18.28 MJ kg(-1). Catalysts showed different effects on compound types; while the H(3)BO(3)catalyst was active in the formation of the monoaromatic compounds, ZnO catalyst was effective in the formation of polyaromatic compounds.