Production and Analysis of Fast Pyrolysis Oils from Proteinaceous Biomass

Fast pyrolysis of lignocellulosic biomass is a facile method for producing high yields of liquid fuel intermediates. However, because most fast pyrolysis oils are highly oxygenated, acidic, and unstable, identification of feedstocks that produce higher quality pyrolysis liquids is desirable. Therefore, the effect of feedstock protein content was studied by performing fast pyrolysis experiments on biomass with varying protein content. The feedstocks ranged from low-protein content, similar to 5% up to feedstocks with > 40 wt.% protein content. Protein content was not a major factor in the yield of pyrolysis oil or the distribution of biomass carbon into the pyrolysis products. However, elevated levels of protein did cause a deoxygenation effect in the pyrolysis process with more of the oxygen rejected from the biomass as water. The deoxygenation caused the pyrolysis oil from the higher protein containing biomass to have higher energy content. Furthermore, the concentration of basic nitrogen groups caused the pyrolysis oil from the higher protein biomass to shift to a more neutral pH and lower total acid number than has been measured typically for lignocelluloic biomass pyrolysis oils. Some of the pyrolysis oils, particularly those from the mustard seed family presscakes exhibited better thermal stability than low-protein pyrolysis oils.