Apisada Tandhapongse, Nakorn Worasuwannarak and Navadol Laosiripojana
Abstract: The 50:50 w/w blended of organosolv lignin from the fractionation of bagasse and eucalyptus was successfully converted into carbon fiber. The properties of isolated lignin samples were studied and analyzed by elemental analysis (CHNO), Fourier transform infrared spectroscopic (FT-IR), Nuclear Magnetic Resonance Spectroscopy (H-NMR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC). The images of carbon fibers were observed by scanning electron microscope (SEM). The blended organosolv lignin could be melt spun at 140°C to form lignin fibers. The collected fibers had medium brittleness. The fibers could stabilize at 250°C under air at rate 0.1°C per minute however, some of areas of the fibers were slightly fused. Then, the fibers were carbonized under nitrogen at 900°C. The received blended organosolv lignin based carbon fibers had carbon content at 82.84%. The carbon fibers had smooth surface with the diameter of 13-20 µm. The 50:50 w/w blended of organosolv lignin from bagasse fractionation and organosolv lignin from eucalyptus fractionation had average electrical resistivity of 3x10-2 Ωm which had a potential to be used as semiconductor material.
Keywords: Lignin fiber, Fractionation, Organosolv lignin, Melt spinning, Carbon fiber.
Shabbir H. Gheewala*, Thapat Silalertruksa, Pariyapat Nilsalab, Naruetep Lecksiwilai, Wanchat Sawaengsak, Rattanawan Mungkung and Jirawat Ganasut
Pornlada Daorattanachai*, Sansanee Totong and Navadol Laosiripojana
Abstract: The purpose of this work was to investigate catalytic non-oxidative dehydrogenation of ethanol into acetaldehyde and hydrogen using monometallic Cu, Ag and bimetallic Cu-Ag catalysts supported on SiO2 at metal loading variations (2.5, 5, and 10 wt.%). The experimental results revealed that Cu catalysts with low Cu loading (2.5-5 wt.%) exhibited better activity than Ag catalysts in temperature range of 250-400°C. Moreover, we found that the addition of Cu considerably promoted the catalytic dehydrogenation activity of Ag/SiO2 catalysts. Among all prepared catalysts, the 10 wt.% Cu-Ag/SiO2 showed the best catalytic activity for non-oxidative dehydrogenation of ethanol with ethanol conversion of 53%, acetaldehyde yield of 42%, and hydrogen yield of 49% at 400°C.
Keywords: Dehydrogenation; Ethanol; Acetaldehyde; Hydrogen; Cu; Ag; Cu-Ag.