Oregon’s Willamette Valley is the largest producer of hazelnuts in the United States utilizing approximately 65,000 tons of whole hazelnuts in a single season. While the nut itself is of interest to the food-retail industry, hazelnut shells could be ready for a bigger role in energy and agricultural markets. Since the oil crisis of the 1970’s, sustainable derivation of chemical feedstocks from renewables as an alternative to petroleum-based feedstocks will be integral to reducing economic reliance on politically unstable regions. Further, climate change disruptions in agricultural practices, namely, air pollution, have prompted the investigation of soil ameliorants to restore soil health and improve plant growth. Of the several biomass feeds currently researched, hazelnut shells are unique in their ability to produce both a renewable bio-oil feedstock and a biochar soil ameliorant via pyrolysis. In this line of inquiry, a pyrolysis unit was designed to process 10,000 tons of hazelnut shells seasonally for Clark Farms Nursery, of Cascade Foods in Albany, Oregon. Central to the design is the implementation of a cutting-edge auger reactor employed to minimize attrition phenomena characteristic of a standard fluidized bed. An auger reactor, in which a screw conveys preheated steel shot and hazelnut shells from a feed hopper, heats the shells in the absence of oxygen whilst ensuring uniform heat transfer to optimize biochar collection. In addition to the pyrolysis unit design, a technoeconomic and safety analysis is presented with a final conclusion on the overall viability of the venture.
