Poultry Droppings Make for a Great Fuel
You can't stop progress: turning chicken droppings into electricity is one thing, but developing transportable pyrolysis units to convert poultry droppings into bio-oil on-the-go? A team of scientists from Virginia Tech's College of Agriculture and Life Sciences is working with a coalition of poultry growers to test a transportable unit that would convert poultry litter — a mixture of manure, feathers, bedding and spilled feed — into bio-oil (or pyrodiesel), producer gas and fertilizer.
It would do so by first heating the litter until it vaporized; the vapor would then be condensed to make the bio-oil. At the same time, a form of slow release fertilizer could be recovered from the pyrolysis unit. The main advantage of this system is its self-sufficiency: the vapor generated by heating the biomass can be used to power the unit. "The self-contained transportable pyrolsis unit will allow poultry producers to process the litter on site rather than having to haul the litter to a separate location. In addition, the thermochemical process destroys the microorganisms reducing the likelihood of the transmission of disease to other locations," said Foster Agblevor, the lead researcher on the project.The large amount of poultry litter produced each year — above 5.6 million tons — makes this technology highly applicable. In addition to providing an economical, efficient means of creating bio-oil, this transportable pyrolysis unit has several concrete environmental benefits as well: it would greatly ameliorate the logistics of biofuel production (by reducing inefficiencies related to biomass transportation), cut down water contamination and reduce the threat posed by many litter-borne diseases, such as avian influenza. According to Agblevor, bio-oil yields range from about 30 - 50% by weight — depending on the bedding content and age of the litter (the higher the bedding content, the larger the yield).
"The type of poultry litter used will affect the amount and quality of the bio-oil produced and ultimately will impact the producer's profitability. Finding the right set of conditions for the poultry litter is key to the adaptation of this technology," said Agblevor.