THERMOLYSIS OF ORGANOSOLV LIGNIN IN SUPERCRITICAL WATER AND SUPERCRITICAL METHANOL

The thermolysis of organosolv lignin in supercritical water and superc ritical methanol has been examined to investigate the relations betwee n oil and char yields and reaction conditions. Reactions were carried our at temperatures of 623, 648, 693 K and pressures of 10, 20, 30, 40 MPa for 1 h. It was found that the formation of char is suppressed an d reactions for oil production became predominant at lower temperature s and higher pressures. Using the data from elemental analysis and H-1 -NMR for the oils, concentrations of 8 types of functional groups were determined from structural characterization analysis, For the oils pr oduced from the reactions in supercritical water, relatively high conc entrations of hydroxy groups were observed due to the dominant solvoly sis pathway in supercritical water. The oils from supercritical methan ol reactions have high aromaticity indicating that the pyrolysis pathw ay becomes dominant in supercritical methanol. The catalytic activitie s of Na2CO3 and hydrophilic smectites in supercritical fluid reactions were investigated from the measurements of oil and char yields. Oil a nd char did not affect the reactions in supercritical methanol. On the other hand, the oil yield increased for the reactions under high pres sure conditions in supercritical water.