Industrial single-screw and twin-screw prototype reactor pyrolysis for bio-oil and charcoal production from biomass: A case study of cogon grass (Imperata cylindrica)

Abstract

Biomass conversion by pyrolysis process is important in renewable energy because the current global situation changes the use of energy in various forms according to the demand. The pyrolysis process is different in terms of temperature, pressure, reactor type and biomass control before entering the reactor. This research compares the efficiency of single-screw pyrolysis reactor and twin-screw pyrolysis reactor in producing bio-oil from cogon grass (Imperata cylindrica) for industrial development by analyzing the oil content and chemical and physical properties of bio-oil from pyrolysis process at temperature between 400 °C and 500 °C. The analysis of biomass, bio-oil and charcoal properties was performed using physicochemical methods and GC–MS. The results showed that the liquid phase from the pyrolysis process using a twin-screw at 500 °C had the highest value of 58.75 % and 37.39 % bio-oil. In comparison, the bio-oil yield from single-screw at 500 °C was 55.23 % liquid phase and 33.76 % bio-oil. GC–MS analysis revealed that the majority of hydrocarbon compounds were phenol, benzene, 1-ethyl-3‑methoxy, and pyridine 2-methyl. The bio-oil from the twin-screw reactor contained more benzene, 1-ethyl-3‑methoxy, and pyridine 2-methyl than the bio-oil from the single-screw reactor. The carbon content of the bio-oil from the twin-screw reactor (53.23 wt%) was higher than that of the bio-oil from the single-screw (38.23 wt%). The bio-oil from the twin-screw reactor had a higher heating value than the bio-oil from the single-screw reactor at all temperatures. The viscosity of bio-oil from the single-screw reactor had a low point (0.353 Pascal/min) at 25 °C, which was equal to that of bio-oil from the twin-screw reactor (0.354 Pascal/min). Single-screw reactors and twin-screw reactors are efficient in producing bio-oil, especially twin screw reactors. The results of this research are pilot projects to establish industrial pyrolysis reactors focusing on biomass conversion to energy fuels for further sustainable domestic energy development.