Energy & Fuels, Vol.25, No.11, 5438-5443, 2011
Study of Catalytic Hydropyrolysis of Rice Husk under Nickel-Loaded Brown Coal Char
The hydropyrolysis of rice husk was carried out in a fluidized-bed reactor. To determine the optimal condition for the bio-oil yield and investigate the effects of an inexpensive nickel-loaded Loy Yang brown coal (Ni/LY) char activity on the product yield and composition, the non- catalytic hydropyrolysis was tested under different reaction conditions (gas flow rate, static bed height, and temperature). The maximum bio-oil yield of 47.06% was obtained at a gas flow rate of 2 L/min, a static bed height of 5 cm, and a temperature of 500 degrees C. In the presence of the catalyst, the bio-oil yields markedly reduced, while the gas yield and water content showed an opposite trend. The influence of the catalyst was to convert the oxygen content in bio-oil to the formation of H2O, CO, and CO2. The oxygen content of bio-oils decreased, whereas the higher heating value of bio-oils increased when increasing the volume fraction of Ni/LY char. The bio-oil with the lowest oxygen content (20.7 wt %) and the highest heating value (30 MJ/kg) was obtained with a 75% volume fraction of the catalyst. The catalytic hydropyrolytic oil contained more aromatic hydrocarbons with slightly reduced oxygenated compounds than the non-catalytic hydropyrolytic oil. The high amount of aliphatic and aromatic hydrocarbons was obtained from hydropyrolysis, with the volume fraction of Ni/LY char >50%. The results indicated that the bio-oils from the hydropyrolysis, using Ni/LY char, contained more aromatic hydrocarbons with slightly reduced oxygenated compounds and can be used as liquid fuel and chemical feedstock.