Engineering R&D: Biotrickling reduces bakery ethanol emissions by 85-100 percent
A four-month pilot study conducted at the Interstate Brands Wonderbread Bakery in Columbus, OH concluded that a two-stage biotrickling filter composed of environmentally-available bacteria immobilized on solid polypropylene fibers reduced ethanol emissions by 85 to 100 percent. As shown on the table on page 28, the system averaged 91 percent ethanol-removal efficiency during the study period, excluding filter downtime.
The project was funded by the EPA, USDA, the Lincoln Food Processing Center at the University of Nebraska and the American Bakers Association (ABA). The EPA supplied the trailer-mounted biofiltration unit, designed by PRD Tech, Inc. and incorporating proprietary PRD support media. PRD Tech worked with with the department of chemical engineering at the University of Cincinnati to conduct the study. Malcolm Pirnie, Inc. (Columbus, OH) designed and installed the duct work connecting the oven-stack to the biofilter.