(214b) Upgrading of Bio-Oil As Transportation Fuel Using Water/Oil Based Extraction

Authors: 
Dolah, R., Massachusetts Institute of Technology
Karnik, R., Massachusetts Institute of Technology
Hamdan, H., Universiti Teknologi Malaysia
Conversion of biomass into biofuels is a promising approach for the production of renewable fuels to replace liquid fuels in aviation and other modes of transport. Although the share of biomass in the total final energy consumption by end-use sector is 14%, majority of it is in heating and cooling (12.6%) and only 0.8% is in transportation. The challenge is the incompatible properties of bio-oil including low heating value, thermal instability, and high corrosivity that necessitates upgrading. Water-oil extraction is investigated as a simple and inexpensive upgrading method that can improve the properties of bio-oil by extracting corrosive and thermally unstable acidic compounds by using their greater polarity and preferential solubility in water. In this paper, pine wood is used as bio-oil and water-oil extraction is performed by mixing water and bio-oil which forms an aqueous phase (water soluble fraction) and an organic water-insoluble fraction (or “pyrolytic lignin”). Removing the aqueous phase which is composed of high-polarity compounds such as formic acid, acetic acid, and ketone results in “upgraded” bio-oil. The water-insoluble fraction is expected to have notably lower acidity, increase its pH, reduced oxygen and its water content. Parameters in water extraction are investigated for optimization of the water extraction process for the bio oil which includes water temperature, stirring time, and water-bio oil ratio. The properties of water-insoluble fraction are characterized and compared with the initial bio oil without water extraction.

Keyword:

Biomass renewable energy, fast pyrolysis, bio oil upgrading, water extraction, pyrolytic lignin