Bio-oil Production from Napier Grass Using a Pyrolysis Process: Comparison of Energy Conversion and Production Cost between Bio-oil and Other Biofuels

Wasakorn Treedet, Ratchaphon Suntivarakorn, Ilham Mufandi, Piyapong Singbua


This article presents bio-oil production from Napier grass by using a pyrolysis process. The comparative potential of energy conversion and the cost of production among bio-oil, bio-ethanol, biogas and syngas from gasification by using Napier grass as raw material were also analyzed. The pyrolysis in this study was developed from previous work in order to improve the yield of bio-oils. The circulating fluidized bed reactor (CFBr) was used as the reactor, and a new scrub condenser was applied in order to increase the performance of condensing vapor into bio-oil. This system had the ability to feed Napier grass between 45-75 kg/hr, and it could create a solid-recirculating rate of about 52.36 kg/m2s at 7 m/s of maximum superficial velocity. From the results of the bio-oil production, it has been concluded that the maximum yield of bio-oil production is 44.60 wt% at a feed rate of 60 kg/hr and bed temperature of 480°C. The properties and chemical components of bio-oil were also determined. A comparison of energy conversion from Napier grass to products such as bio-oil, ethanol, biogas and syngas through the gasification process as well as an analysis of cost of production revealed that syngas production through gasification has a greater potential energy conversion and cost of production than other technology, which had an energy conversion efficiency and cost of production of about 72.65% and 0.26 USD/GJ, respectively. However, as compared to liquid fuel, the gas fuel has greater limitations in terms of utilization and transportation. The bio-oil production from pyrolysis in this study had a cold efficiency and cost of production of about 28.24% and 17.98 USD/GJ, which proved a more advantageous trend of cold efficiency and production cost than bio-ethanol production, thus it can support a large energy project to create more energy security.


bio-oil; CFBr; energy conversion; Napier grass; production cost.

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