Fuel Science & Technology International, Vol.13, No.7, 895-909, 1995
LIQUEFACTION OF CELLULOSIC WASTE .5. WATER FORMATION AND EVALUATION OF PYROLYTIC CHAR AS A BY-PRODUCT OF PYROLYSIS REACTION
Liquid hydrocarbon oil and water have been produced from the liquefaction of cellulosic matter present in municipal solid wastes (MSW). Gases and residual char have also been produced as by-products resulting from the pyrolysis reaction of cellulose. Quantities of water and pyrolytic char were estimated at different conditions of the process (temperature pressure of hydrogen, carrier oil medium and concentration of boric acid). From the results obtained, it was suggested that the formation of water seems to be sensitive to the operational conditions which enhance a water-gas shift reaction (in which water molecules are consumed to produce carbon dioxide and hydrogen). Decreasing of the undesired chary by-product could be achieved by increasing the concentration of boric acid that catalyzes the liquefaction reaction. Two petroleum distillates, namely gas oil and residual fuel oil, were used as carrier media of a solid refuse. It was found that fuel oil is more efficient as a buffering medium that prevents cellulose macromolecules from a rapid and complete charing during the liquefaction process. The pyrolytic char was characterized and evaluated by means of different analytical procedures and solvent extraction using petroleum ether 40-60 degrees C and methanol. Calorific value of the pyrolytic char was found to be 4.6 Kcal g(-1) which is quite close to that of a brown coal. Dropping point test of the extracted material by petroleum ether indicated that the extract can be utilized for producing lubricating greases via saponification with a salt of sodium or calcium.