(657a) Physicochemical Properties of Upgraded Bio-Oils from Catalytic Pyrolysis of Biomass: A 13C NMR Spectroscopic Investigation to Understand the Effects of the Chemical Composition of the Oils

The production of infrastructure-ready biocrude oil from catalytic pyrolysis offers an opportunity to co-process biomass derived intermediates alongside petroleum feedstocks such as atmospheric gas oil (AGO) and vacuum gas oil (VGO) in standard refinery units. Recent studies [1-4] suggest that, up to 20wt% of upgraded bio-oils can be directly cracked in fluid catalytic cracking (FCC) process with these petroleum feedstocks without affecting the yields. Nevertheless, one of the critical success factors for commercial scale bio-oil co-processing is the physicochemical properties of the upgraded bio-oil. Since the upgraded bio-oil produced in catalytic pyrolysis is not completely free of oxygenated species, there is the need to fundamentally understand the impact of its chemical composition on the physicochemical properties. In this work, several upgraded bio-oils with varying fuel qualities produced from catalytic pyrolysis of different biomass feedstocks with HZSM-5 at 475 ^oC were characterized. The kinematic viscosities ranged from 4 to 60 cSt; the pH values were between 3.2 and 5.0; the storage stability varied from 0.02 to 0.84 cSt/day; the densities were within 0.96 and 1.14 kg/m³, the O/C molar ratios ranged from 0.1 to 0.28; and the nitrogen contents were between 0.1 and 2.12 wt%. Using ¹³C NMR spectroscopy and Pearson correlation coefficients, we were able to establish relationships between the various functional groups and the following physicochemical fuel properties: long-term storage stability, acidity, viscosity, density, solid residue, and elemental composition. The evidence from this investigation suggests that residual oxygenated species such as phenolics, anhydrosugars, and carbonyls continue to negatively impact the fuel properties of even upgraded bio-oils with low oxygen content levels (e.g.,12 wt.%.).  In this talk, we will also discuss the opportunities and challenges of utilizing biocrude oil as a feed for standard refinery units.

References

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3.         Fogassy, G., N. Thegarid, Y. Schuurman, and C. Mirodatos, The fate of bio-carbon in FCC co-processing products. Green Chemistry, 2012. 14(5): p. 1367-1371.

4.         Thegarid, N., G. Fogassy, Y. Schuurman, C. Mirodatos, S. Stefanidis, E.F. Iliopoulou, K. Kalogiannis, and A.A. Lappas, Second-generation biofuels by co-processing catalytic pyrolysis oil in FCC units. Applied Catalysis B: Environmental, 2014. 145(0): p. 161-166.