Experimental Study on Sugarcane Bagasse Pyrolysis in a Hermochemical Processes Pilot Plant

Abstract

This paper investigates the sugarcane bagasse pyrolysis for bio-oil and biochar production in a pilot plant that was designed to perform the gasification process. After some modifications of changing the temperature of fluidized bed reactor and the catalytic reforming reactor, the fast pyrolysis process was performed at 500–600 °C using a fluidized bed reactor (air flow rate: 20–70 L.min-1) under atmospheric pressure, with sugarcane bagasse feeding (2–3.5 kg.h-1) with particles size less than 1.18 mm. Fluidization tests were performed with air feed (oxidative pyrolysis), to guarantee the fluidization is occurring, finding that the minimum fluidization rate was 22 L.min-1 (minimum velocity of gas: 6.3 cm.s-1). The residence time was 7 seconds (ratio between empty reactor volume by fluidizing gas flow). The highest bio-oil yield of 7.43 wt. % was obtained at 500 °C, with a bagasse flow rate of 3.5 kg.h-1 and 25.93 L.min-1 of air flow rate, and this low yield can be explained by the inefficient heat exchanger used. On the other hand, biochar yield achieved 35.88 wt. % using a temperature of 570 °C, 3.1 kg.h-1 of bagasse flow rate, and 28.26 L.min-1 of air flow rate. Considering this pilot plant has never operated in a pyrolysis mode, these results demonstrate that pyrolysis can be applied to this pilot plant, being versatile for different types of processes with a great potential for biochar and bio-oil production besides the high gas production.