(780e) Evaluation of Bio-Oil Corrosion Characteristics

Patrick A. Johnston¹and Robert C. Brown^1,2

¹Center for Sustainable Environmental Technologies; ²Department of Mechanical Engineering

Iowa State University

Ames, IA 50011

Petroleum crude oils contain naphthenic acids that are one of the main causes of corrosion in the petroleum industry during storage, transport, and refining. “Naphthenic Acid Corrosion” NAC has been related to three parameters: Total Acid number (TAN), temperature, and flow rate [1, 2, 3, 4]. Bio-oils do not contain naphthenic acids but do however contain other organic acids such as acetic, formic, glycolic and propanoic acid that may have similar consequences to metal surfaces. A comprehensive corrosion study needs to be completed to determine the actual effects of the organic acids in bio-oil on select metal surfaces. As a result of this study, acid number and corrosion potential of pyrolysis bio-oils can be correlated and ranked to produce a fraction that is non-problematic with typical petroleum refining equipment.

The proposed project will evaluate and compare corrosion and acid number (AN) on fast pyrolysis bio-oil stage fractions produced at Iowa State University (ISU).  The corrosion characteristics will be evaluated using a vacuum distillation apparatus that will simulate a distillation tower in a petroleum refinery. Metal specimens will be subjected to both the liquid and vapor phase of the bio-oil.  Method D664 “Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration” will be used to determine acidy of the bio-oil samples.  Ion Chromatography (IC) and High Performance Liquid Chromatography (HPLC) will be used to quantify organic acid concentration.  The corrosiveness will be ranked gravimetrically according to mass loss during the study.  Selected metal specimens will also be examined by Scanning Electron Microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS) to determine morphological and composition changes on the metal surfaces.

References:

1. A. Jayaraman, H. Singh, and Y. Lefebvre, Rev. Inst. Fr.Pet.41, 265 (1986).

2. C. M. Cooper, Hydrocarbon Process.51, 75 (1972).

3. E. Babaian-Kibala, H. L. Craig, G. L. Rusk, et al., Mater.Perform. 32, 50 (1993).

4. E.B. Zeinalov, V.M Abbasov, and L.I. Alieva, Petro. Chem.49, 185 (2009).