Liquefaction of ammonia and cellulose: effect of nitrogen carbon ratio in the feedstock

The effect of the N/C (Nitrogen/Carbon (weight/weight)) ratio on the behavi or of nitrogen in biomass liquefaction was examined. Cellulose and ammonia were selected as the simplest carbon and nitrogen sources, respectively. Af ter reaction at 300 degrees C for 1 h, the reaction mixture was separated i nto oil-A (water soluble), oil-B (water insoluble), aqueous phase and resid ue. Both the yield and nitrogen content of the total oil (oil-A + oil-B) in creased with increasing N/C ratio. On the other hand, the yield of residue decreased with increasing N/C ratio. These results show that ammonia acts b oth as a reactant and as a basic catalyst during the liquefaction of ammoni a and cellulose. Distribution of nitrogen in the total oil showed the highe st value (25.0%) at 0.18 N/C ratio and was small in the range of low N/C ra tio. In the aqueous phase, soluble forms of organic nitrogen are recognized , while ammonia nitrogen increased with increasing N/C ratio. Distribution of nitrogen into the residue decreased with increasing N/C ratio. In the ob tained oil, more than 60 compounds were detected by GC-MS. We identified 14 nitrogen-containing compounds, which were partly aromatic compounds. The l iquefaction of cellulose and ammonia consisted of a very complicated combin ation of various reactions. (C) 1999 Elsevier Science Ltd. All rights reser ved.