The Production of Liquid Fuel by Fast Pyrolysis of Biomass

Abstract

The NREL Fast Ablative Pyrolysis Technology was employed to generate oils from various biomass feedstocks. The oil yield from wood (64 percent) was higher than from herbaceous species (51 percent). Biomass oils have potential to be used as fuel though their properties are different from those of petroleum derived oils. They are multicomponent mixtures containing various groups of organic compounds such as sugars, aldehydes, acids, and phenolics. The density of the oils is about 1.2 g/ml and the pH is in the range 2.5–3.7. The viscosity of 20–80 cP (at 45°C) corresponds to that of No. 6 fuel oil. The high heating value for the biomass oils is in the range of 22.5–24.4 MJ/kg on a water-free basis. Considering the highest oil yields, it corresponds to approximately 65 percent of the wood heating value transferred to the oil.

Fast pyrolysis of microalgae to produce renewable fuels

“…The high-quality bio-oils are obtained from fast pyrolysis of microalgae. The contents of carbon and hydrogen of bio-oils from microalgae are higher than those of oil from wood [17,19,23] (Tables 3 and 4), whereas the oxygen content is lower than that of wood oil. The H/C and O/C molar ratios are 1.72 and 0.26 on average (Table 3), while the H/C and O/C molar ratios of bio-oil from wood are 1.38 and 0.37, respectively [19].…”

Combustion Properties of Biomass Flash Pyrolysis Oils: Final Project Report

“…Union Fenosa typically uses a eucalyptus feedstock. NREL has worked on development of an ablative vortex design for the pyrolyzer, in which the injected particles are abraded as they travel a helical path along the inside wall of the reactor (Czernik et al, 1995;Diebold and Scahill, 1997). For tie pyrolysis oil combustion work performed at Sandia, NR.ELproduced oils were predominantly tested, because of their wel.1-defmedproduction conditions and the variety of feedstocks and particulate capture schemes used.…”

“…Two different types of hotgas fdtration are indicated for removing entrained char particles from the pyrolyzer exhaust flow: the earlier NREL oils were produced with the cyclone separators, whereas later oils were produced using a high-temperature baghouse. [Schematic based on figures in Czernik et al, 1995, andDiebold andScahill, 1997, and …”

A model for the evaporation of biomass pyrolysis oil droplets

“…Usually only trace amounts of hydrocarbons are present, the vast majority of the components being oxygenates. These fuels are typically denser and more viscous than petroleum fuels, with a specific gravity typically around 1.2 [5,6,10,[22][23][24][25]. The chemical composition may change over time owing to "aging", in which light components are polymerized [18,26,27], and phase separation is also possible [6,7].…”