(669f) Kinetic Study of Dissolution of Biochar in Tetralin | AIChE

(669f) Kinetic Study of Dissolution of Biochar in Tetralin

Authors 

Kundu, R. - Presenter, The University of Tulsa
Ramsurn, H., The University of Tulsa
The need for renewable energy across the world has recently increased due to the effects of global warming. One of the primary alternatives that researchers are investigating, in order to replace or at least complement fossil fuels and mitigate the effects of global warming, is the production of biofuels from biomass. Biomass consists of 30-35 wt% cellulose, 15-35 wt% hemicellulose, and 20-35 wt% lignin. In our research, biochar was first produced from cellulose and lignin by hydrothermal carbonization (HTC). In HTC, each biomass model compound (cellulose or lignin) was mixed with water and heated to 220C-370C in a closed batch reactor to form biochar, a carbon rich solid. In the second step, the dissolution of cellulose and lignin biochar in a hydrogen donor solvent (tetralin) was studied at 400oC (temperature at which tetralin breaks down to naphthalene and hydrogen) for 60 mins. This liquefaction process, analogous to the direct coal liquefaction, has the potential to produce value-added chemicals like aromatics. In order to understand the effect of temperature on product distribution, the dissolution experiments were stopped at various points (200oC, 250oC, 300oC, 350oC and 400oC) during the heating stage. For the isothermal stage at 400oC, the reaction was stopped after 15, 30, 45 and 60 mins to investigate the kinetics of the reaction. The results would provide a detailed look into the conversion of biochar and yield of the different products formed at various stages of the dissolution reaction, crucial for process design. The products formed during dissolution at various stages were analyzed using gas chromatography-mass spectroscopy and mainly consisted of pre-asphaltenes (tetrahydrofuran soluble), asphaltenes (toluene soluble) and oil (hexane soluble).