Fast pyrolysis of Dipterocarpus alatus Roxb and rubber wood in a free-fall reactor

Abstract

Dipterocarpus alatus Roxb, sometimes called the ‘diesel tree’, because its resin has been reported to run small engines directly, has not been studied as a source of bio-oil from pyrolysis, although considerable waste is generated from furniture making. Here, we compared it with rubber tree waste, using cassava rhizomes (already extensively studied as a bio-oil source) as a reference. Our free-fall pyrolysis system used a conventional cooled condenser, as well as an electrostatic precipator, to capture bio-oil. Total bio-oil yields were: D alatus, 62% w/w of input biomass, cassava 61%, rubber wood and leaves, 59%. The electrostatic precipitator was responsible for ~20% of the total bio-oil yield: adding the precipitator increased overall yield significantly. HHV values wre highest for rubber wood (21–22 MJ/kg), but only slightly lower for D alatus and cassava (19–20 MJ/kg). Small differences in the properties of the bio-oil from both condensers confirmed that different fractions of the oils were collected in the two condensers. Overall, D alatus showed good potential as a high yielding source of bio-mass for pyrolysis.