Journal article

Publication year: 2012

Pages: 262-269

Journal: Fuel: The Science and Technology of Fuel and Energy

Volume number: 94

Issue number: 1

ISSN: 0016-2361

eISSN: 1873-7153

DOI Link: https://doi.org/10.1016/j.fuel.2011.08.040

Publisher: Elsevier

Abstract: 
The thermal degradation of free fatty acids and animal fat in a moving bed of sodium carbonate and 5 wt% of water were carried out at 430 +/- 20 degrees C at a pilot scale plant. During start-up the loading rates for a 60: 40 mixture of oleic and stearic acids were 10 kg/h resulting in a 69 +/- 5% of bio-crude. The acidity index was remarkably low within a range of 0.64-0.80 mg KOH/g during 3 weeks of operation. The loading rates for animal fat were increased from 10 to 40 kg/h corresponding to a weight hourly space velocity of 0.03-0.1 h(-1) over a period of 6 months. Heat transfer into the reactor was the limiting criterion. The main product with a yield of 65 +/- 5% was bio-crude showing an acidity index of 0.5-1.8 mg KOH/g. The mean value for kinematic viscosity at 40 degrees C was 1.78 mm(2)/s. The net calorific value of bio-crude was 41.6 MJ/kg. Coke deposits on sodium carbonate were determined to be 5 +/- 1%. The gaseous products ranged from 25 wt% to 30 wt%. The presence of CO2, H-2, CH4, C2H6, C2H4 and C-3 to C-5 hydrocarbons as major components was established by gas chromatography. The gases were directly fed into an on-site gas line and used for heating purposes. The distillation curve of bio-crude from animal fat showed hydrocarbon based bio-fuels in the boiling ranges of gasoline and diesel. Upon rectification 66% of bio-diesel and 21% of bio-gasoline were obtained. This corresponds to a total yield of 43% bio-diesel and 14% bio-gasoline from animal fat. The bio-diesel had favorable low-temperature properties (cold filter plugging point = -18 degrees C) with oxidation stability between that of mineral oil based diesel and fatty acid methyl ester fuels. The gasoline fraction lacked low-boiling hydrocarbons as indicated by a vapor pressure of 26 kPa instead of 60-90 kPa (DIN EN 228). Thus, water-cooled condensers need to be improved for a full-scale plant. The results are discussed in terms of German specifications for standard fuels. (C) 2011 Elsevier Ltd. All rights reserved.

Harvard Citation style: Weber, B., Stadlbauer, E., Stengl, S., Hossain, M., Frank, A., Steffens, D., et al. (2012) Production of hydrocarbons from fatty acids and animal fat in the presence of water and sodium carbonate: Reactor performance and fuel properties, Fuel: The Science and Technology of Fuel and Energy, 94(1), pp. 262-269. https://doi.org/10.1016/j.fuel.2011.08.040

APA Citation style: Weber, B., Stadlbauer, E., Stengl, S., Hossain, M., Frank, A., Steffens, D., Schlich, E., & Schilling, G. (2012). Production of hydrocarbons from fatty acids and animal fat in the presence of water and sodium carbonate: Reactor performance and fuel properties. Fuel: The Science and Technology of Fuel and Energy. 94(1), 262-269. https://doi.org/10.1016/j.fuel.2011.08.040