The Sunday afternoon tour began at North Carolina State University's
(NCSU) experiment farm south of Raleigh at the Animal and Poultry Waste
Management Center. Hosts, Chris Hopkins, Extension Associate and Preston
Burnette, Site Manager presented the basic science and scope
of their portable torrefier machine. The torrefier is a controlled
pyrolysis device that "toasts" green chips under controlled temperature
and oxygen and is largely fueled by the gases released within the
exothermic heating process. Chris and Preston took turns explaining
their justification for the design and building of their prototype and
second full-scale unit with grant dollars, namely: decrease the water
content, perishability, and the logistical constraints of transporting
green biomass, while adding value and increasing heating value of
chipped logging debris.
Joe James from Agritech Producers explained his efforts to commercialize
the NCSU torrefier and welcomed questions from the audience. The tour
included a hands-on look at the machine and a discussion ensued about
the process, including yield, fuel consumption, energy balance estimates
and general experiences related to torrefying wood ships and ground
switch grass.
The Tour then proceeded to Progress Energy's Cape Fear (310 MW coal-fired) power generating station in rural Moncure, NC. A presentation of on the co-firing challenges and opportunities was made by Progress's biomass engineer Grant Blume. Attendees toured the complete plant from coal delivery , pulverizing and injection systems to the automated control room. After a trip to the top of the seven story generating station and a panoramic view, attendees returned to a summary presentation of the co-firing process of coal and biomass, lessons learned, and the anticipated position of woody biomass and residuals in Progress's energy portfolio.
The Cape Fear facility will be the location of a test firing of torrefied wood chips in the coming months to test its co-firing compatibility. The tour returned to the Raleigh Convention Center in time to join the welcome reception already in progress.