This Is AuburnElectronic Theses and Dissertations

Production of High pH Value Bio-oil from Woody Biomass and Poultry Litter




Ravindran, Harideepan

Type of Degree



Mechanical Engineering


Fast pyrolysis, a biomass to liquid conversion process, has attracted a lot of interest from industry and academia due to its high oil yield. Bio-oil can be produced from various biomass feedstocks that are regionally appropriate. Small diameter trees removed from forests have very little economic value in the current market, and the utilization of underutilized biomass to bio-oil could be a niche market for energy production. Also, Alabama is the third largest poultry producing state, and has substantial amount of poultry litter available. The main objective of this work was to produce high pH value bio-oil using cheap and simple methods. Apparently, this study was divided into three specific objectives in which the first task focused on determining maximum bio-oil production from selected biomass and their pH value. The second and third tasks comprised of experimentation and evaluation of new techniques to produce high pH value bio-oil. The first task evaluated bio-oil production from pine wood, underutilized forest biomass, and poultry litter at different temperatures in between 425-500oC, and characterized according to the ASTM Standard (D7544-09) to document the effect of temperatures. The study found that pine wood gave the highest bio-oil at 500oC, but the poultry litter bio-oil showed the highest pH. In the second and third tasks, cheap and simple methods, such as using a bio-based additive (poultry litter) with primary biomass (pine wood), and through cascade (2- stage) pyrolysis process, were used to produce high pH value bio-oil. From the studies, it was found that the pH value of bio-oil increases while increasing the composition of the additive in the primary biomass. However, the bio-oil produced from 15 wt.% poultry litter in pine wood did not meet selected properties recommended by the ASTM Standard. Further, the pH value of bio-oil obtained from 2-stage process was slightly higher when compared to the bio-oil produced from single stage process. Here, style of references used in the journal “Bioresource Technology” was followed in this report.