Fast pyrolysis from Napier grass for pyrolysis oil production by using circulating Fluidized Bed Reactor: Improvement of pyrolysis system and production cost

This article focused on production cost of pyrolysis oil production of Napier Grass in Circulating Fluidized Bed Reactor (CFBr) which sand was used as bed material. The Napier grass was converted to pyrolysis oil by using fast pyrolysis process. The reactor temperature, superficial velocity (Uf) and feed rate of feedstock were adjusted in order to find the best condition of this experiment, and the Quadratic Response Model was used to predict the yield of pyrolysis oil and the optimum condition coupled with the experiment. From a results of this experiment, it was found that the maximum pyrolysis oil production was 36.93 wt% at 480 ºC of bed temperature, 7 m/s of superficial velocity and 60 kg/hr of feed rate, while the result from the Quadratic Response Model indicated that the maximum pyrolysis oil production was 32.97 wt%. From the analysis of properties of pyrolysis oil, results showed that heating value, density, viscosity, pH and water content were 19.79 MJ/kg, 1,274 kg/m 2.32 cSt, 2.3 and 48.15 wt%, respectively, and the ultimate analysis was also determined. From the analysis of the efficiency of energy conversion, it was concluded that the value of cold efficiency and total energy conversion to pyrolysis oil in this system were 24.88% and 19.77%, respectively. The greatest energy consumption in this system was made by the energy from the heating process. Furthermore, from the calculation result of production cost in this study, it was concluded that a production cost of pyrolysis oil was 0.481 $/liter or 9.88 $/GJ at the 75 kg/hr of feed rate.